UNIVERSITY OF CALIFORNIA AT LOS ANGELES THE PESTS AND BLIGHTS OF THE TEA PLANT A REPORT OF INVESTIGATIONS CONDUCTED IN ASSAM AND TO SOME EXTENT ALSO IN KANGRA GEORGE WATT, M.B., C.M., F.L.S., C.I.E., OFFICIER D'ACADEMIE; CORRESPONDING MEMBER, ROYAL HORTICULTURAL SOCIETY OF ENGLAND. REPORTER ON ECONOMIC PRODUCTS TO THE GOVERNMENT OF INDIA. CALCUTTA : OFFICE OF THE SUPERINTENDENT, GOVERNMENT PRINTING, INDIA. 1898. *\ce $U CALCUTTA : GOVERNMENT OF INDIA CENTRAL PRINTING OFFICE, 8, HASTINGS STREET. .' ! SB CONTENTS. PAGE CHAPTER I. EXTENT OK PERSONAL EXPLORATIONS I. Localities visited and. dates of Tour in Kulu and Kangra ...... 3 II. Localities] visited and dates of Movements in Assam ...... ib. CHAPTER II. INDICATIONS OF DETERIORATION- HI. Some General Considerations on results ob- tained 8 IV. Treatment of Blights and Pests ... 9 V. Influences of cultivation .... 14 VI. Vegetable Blights 20 VII. Insect and other Animal Pests ... 25 VI II. Influence of Jats of Tea on the Development of Blights and Pests .... 29 CHAPTER III. -PLANT LIFE IX. Nutritive and Reproductive systems . . 33 X. Circulation of Sap 35 XL Conditions of Maturity .... 37 XII. Practical Lessons to be Learned ... 38 CHAPTER IV. SEED GARDENS AND THE IMPROVEMENT OF SEED XI II. Indigenous Seed 41 XIV.- Seed Gardens 50 CHAPTER V. HOEING AND WEEDING XV. Change in Relation to Disease ... 55 XVI. Objects of Tillage . . . . ib. XVII. Opinions of Authors on Hoeing of Tea Estates 58 XVIII. Advantages and Disadvantages of Weeds . 61 CHAPTER VI. DRAINAGE OF TEA GARDENS XIX. Water and its Relation to the Soil . . 66 XX. Water and its Relation to the Plant . . 69 XXL Indian Authors on Tea Drainage % 72 XXII. Conditions of Successful Drainage . . 78 XXIIL Assam Method of Surface Drainage . . 80 XXIV Position of Drains 85 XXV. Sub-Soil or Pipe Drainage Recommended . 88 XXVI. Burying of Prunings in Drains , 94 20644 ii CONTENTS. CHAPTER VII. PRUNING PAGE XXVII. Diversities in Pruning .... 97 XXVIII. Theory of Pruning 99 XXIX. Position and Angle of Section ... 102 XXX. Shape of the Tea Bush .... 105 XXXI. Season of Annual Pruning . . . . 114 XXXII. Requirements of Flushing .... _ii6 XXXIII. Nature and Extent of Annual Pruning. . 117 XXXIV. The Collar or Point of Union of Root to Stem 121 XXXV. Imperfect Collar Pruning .... 122 XXXVI. Collar Pruning satisfactorily performed . . 125 CHAPTER VIII. PLUCKING XXXVII. Continuous Production of new shoots . . 131 XXXVIII. Plucking for Quantity or for Quality . . 134 XXXIX. Number of Leaves Left on the Plant . . 141 XL. Opinions of Indian Authors on Plucking . 145 XLI. Over-Plucking Injurious . . . . 153 XLII. Deterioration in Yield and Value of Produce . 155 CHAPTER IX. TEA FERTILISERS XLIII. General Principles of Manures and Manuring 161 XLIV. Manures for Tea . . . . . . 164 XLV. Green Manuring . . . . . 166 XLVL Nitrification ... . , . 168 XLVIL The Fixation of Nitrogen by Plants . . ib. XLV III. Soil Inoculation 174 XLIX. Concluding Remarks on Tea Fertilisers . 175 CHAPTER X -THE TEA PESTS L. Introductory Observations . . . . 178 LI. Sources of Information and Assistance. . ib. LI I. The Beetles .'-.':. . . . 182 LI 1 1. Other Beetles reported as attacking the Tea 194 CHAPTER XL LEPIDOPTBRA- L IV. The Moths and Butterflies . . . 195 LV. Bag-worms, Faggot-worms, etc. ... 201 LVI. Wood-boring Caterpillars .... 217 LVIL Slug-like Stinging Caterpillars ... 220 LVIII. Hairy Caterpillars ..... 228 LI X. Nocturnal Moths with Mostly Naked Cater- pillars 24 o LX. Leaf-Rollers and Leaf-Tiers ... 243 CONTENTS. Ill CHAPTER XII. DIPTERA PAGE LXI. The Flies, Gnats, Daddy Longlegs, Hessian Fly, Gad Fly, Horse and Cattle Flies, etc. . 255 LXI I. The Saw-flies, Gall-flies, Ichneumon-flies, Bees, Wasps and Ants 257 LXI 1 1. The Grasshoppers, Crickets, Locusts, etc. . 260 CHAPTER XIII. HEMIPTBRA OR RHYNCHOTA LXIV. Tea-Musquito, Green-fly, Aphides, Plant- Lice, Scale-Insects, Plant-Bugs, etc. . . . 264 LXV. The Thrips 337 CHAPTER XIV. PSEUDONEUROPTERA LXVI.-Termitidae or White-ants .... 339 CHAPTER XV. OTHER ANIMAL PESTS- LXVIL The Snails and Slugs 370 LXVIII. The Julus-worms or Mellepedes ... 371 CHAPTER XVI. ARACHNOIDBA LXIX. The Spiders, Mites, Scorpions, etc. . . 373 CHAPTER XVII. VEGETABLE PARASITES OF THE TEA PLANT: THE BLIGHTS LXX. Leaf Parasites or Blights . . . . 412 LXXL Blights on the Stem 433 LXXII. Fungi on the Roots of the Tea Plant . . 459 THE PESTS AND BLIGHTS OF THE TEA PLANT BEING A REPORT OF INVESTIGATIONS CONDUCTED IN ASSAM AND TO SOME EXTENT ALSO IN KANGRA. CHAPTER I. EXTENT OF PERSONAL EXPLORATIONS. IN response to an application made by the Indian Tea Association, the Government of India authorized me to pay a visit to certain of the Tea Districts in order to institute enquiries mainly into the subject of Tea Blights and the value of Adhatoda Vasica as an insecticide against the injury done by the more alarming insect pests. 2. The greater importance of Assam as a tea-producing country has necessitated a larger portion of this report being devoted to the particulars learned in that province than has been given to Kangra. It is believed, however, that the opinions advanced are applicable not only to Assam and Kangra, but to some extent at least to the tea dis- tricts of India as a whole. The present report is intended purely and simply as a popular statement, since it would take many years to do justice to the subject or even to fully work up the mass of material that had been collected during the few months sr^nt in Assam and Kangra. It is issued in the hope that it ma/ prove of some slight practical value, but chiefly from the expectation that I Official Instructions. Adhatoda. Cow/, with paras. 2O-2, 292, 573, 689, 704, 742, 758 and 795. Nature of Report. COM/, with paras. 54, 55, 92, 316. . :.*:. : *. "fte'port'bf Investigations in Assam Extent of Personal Explorations. Future Enquiry. General Principles. Collections of Pests. Names of Tea Gardens. may possibly succeed to awaken interest in certain directions and in subjects of enquiry that need to be very considerably elaborated before anything of a definite character can be established. By having a report that touches on such points, though only in a popular (and one might almost call it a speculative) form, it may be possible to lay down the lines on which a more detailed enquiry should be conducted. But I may say at once that my visit to Assam convinced me most completely that the investigations I had been deputed to undertake in a few months, could only be accomplished by a scienti- fic officer residing in the tea districts for some ten years or so and conducting a series of complicated and delicate investigations in in- timate association with the planters. In fact the study is one that might easily be regarded as sufficient to occupy the whole time and attention of several investigators for a life-time. The utmost I can hope, therefore, to accomplish by the present report may be said to be, to establish general principles for future guidance; to direct attention to the subjects that seem of greatest moment ; and to con- struct a basis of mutual action between the practical planter and the scientific investigator, who may ultimately work up the material al- ready collected and that which, it is hoped, may be furnished conti- nuously by the planters as one result of this preliminary statement. With the last-mentioned object in view I shall endeavour to exhibit the gaps that require to be filled up in our Museum sets of specimens and to indicate some of the simpler experiments that have to be performed before we can speak even in general terms of some of the most serious blights. 3. The present report will, as far as possible, be confined to the subject of tea and shall only incidentally deal with the other botanical enquiries conducted by me during my explorations in Assam and Kangra. 4' It is not intended that mention should be made of gardens in which certain blights were found to prevail, but it may be of value to record here the chief centres visited by me and the dates of my movements. The periods of appearance and disappearance of certain blights is of distinct importance. Moreover, my not having seen cert a i n blights in some of the gardens visited, may be accounted for by my having reached these gardens too early or too late in the season, as the case may be. Tea Pests and Blights. Extent of Personal Explorations. I. Localities visited and Dates of my Tour in Kulu and Kangra. 5. On the 8th October 1894 I visited Bajoara, and crossing the Babbu Pass into Nugger I followed the valley down to Sultanpur, which was reached on the 27th ; I then directed my steps from Kulu to Kangra vid the Jatingri Pass and reached Baijnath on the 4th November. Several gardens and tea houses owned and worked by Natives were then inspected ; the 6th was spent at Soongal J 7th at Holta; 8th at Palampur; 9th at Gopalpur; and loth at Dharmgiri. As many gardens as possible were visited around the cen- tres named. II. Localities visited and Dates of my Movements in Assam. 6. I left Calcutta on the 1 2th of March and returned again on the 25th July 1895. Deducting the time occupied by journeying in train and steamer to and from the province, it may be said that my explora- tions occupied a little over three and a half months. But of that short period fully one month was taken up in botanical investigations which, from the results obtained, may be pronounced as having had but a negative or at most an indirect bearing on the subject of tea blights. The report which I have now the honour to present represents, therefore, the results obtained during little more than two months' explorations in the Assam tea districts. 7. Sibsagar District. I reached Sibsagar on the i8th March, and up to the 5th April devoted myself to the study of the gardens and neighbouring jungles in the vicinity of Nazira. The following were the chief gardens visited : Ligri Pukri, Mazenga Maikipur, Bamon Pukri, Suntok, Cherideo, Dholebagan, Gileki, Atkhel, and Deopani. From Suntok I went for a few days on an excursion up the Dekho river and collected many plants of interest, but failed to trace more than one or two of the tea blights into the jungles. I also inspected some of the seams of coal in the trans-Dekho Naga country. Simi- larly from Gileki I made a botanical excursion into the jungles on the lower hills that skirt the tea gardens and witnessed the primitive mining operations of the Nagas and others employed on the seams' or rather pouches of nummulilic coal of that locality. I then turned to what may be called the more north-eastern por- tions of the Sibsagar tea district. On the 6th of April I went to TOUR KANGRA. TOUR ASSAM. Sibsagar. Report of Investigations in Assam Extent of Personal Explorations. Dumar Dallang ; yth, Khumtai ; 8th, Moran and Khwang ; gih, Sepon ; loth, Naharar.i; nth, Luckwah ; i2th, Nahorhabi; and i6th, back to Ligri Pukri. 8. Jorhat. I next visited the south-western section of the Sibsagar gardens by revisiting on the i8th and igth Atkhel; Amguri, 2oth and 2ist; Tiphuk, 22nd; Selang, 23rd; Noakachari, 24th; Jetukia (Melang), 25th; Cinnamara, 26th; Moaband and neighbourhood, 9. Golaghat. Nigiriting, 3oth April and ist May; Badalipar, 2nd ; and 3rd to 5th other gardens in the Nigiriting neighbourhood. On the 6th May I proceeded to the gardens near the Golaghat Station. Having already amassed a considerable amount of information regard- ing tea pests and blights, it was felt desirable that I should make a ran through the Naga Hills. Besides the subject of tea, my orders were to institute enquiries regarding other matters and to make cer- tain collections of economic products. I had failed to find in the jungles around the tea gardens more than one or two of the tea blights, and the opinion had been forced on me, therefore, that the majority of the more alarming maladies had been induced by cultiva- tion. It was accordingly recognized as very desirable that I should have an opportunity to study indigenous tea in its natural habitat. 10. Nambar Forest. On the 7th to the loth of May I marched through the Nambar forest to Dimapur. Many botanical and econo- mic collections were made, but again I failed to find any more of the tea blights in these very extensive jungles. Two- plants were, how- ever, seen to be punctured in a manner very similar to that effected by the Tea Mosquito. These were Polygonum sp. and Msesa indica. Although I spent several hours watching the former, I was unsuccessful in identifying the insect, but the puncturings were seen to be very different in shape to those on the tea plant, and therefore I inferred that they were in all probability not caused by Helopeltis theivora the Mosquito. The latter plant (Maesa), a small bush common all over the plains and lower hills of Assam, up to altitudes of 3,000 feet, had its leaves punctured very much like those of the tea plant. I was aware the insect responsible for this had been identi- fied by Entomologists as allied to the mosquito of the tea, though quite distinct. I soon confirmed that opinion. It is a bright red creature, the wingless larvae of which might be described as almost Tea Pests and Blights. Extent of Personal Explorations. scarlet. But to the non-scientific observer it may at once be distin- guished from the enemy of the tea plant by the absence of the drum- stick-like process on the back a structure which may be said to be highly characteristic of Helopeltis theivora. I go into these details here so as to dispose of an insect which has so often been mistaken as the possible origin of the tea mosquito, owing to the very similar appearance of the leaves punctured by it to those of mosquito- blighted tea. I was also aware that, according to several writers, the wild pan (Piper) had been recorded as the plant upon which the mosquito lived, when it could not find tea. It may fairly be said that both during my explorations in the Nambar forests and in the jungles around the tea gardens, I examined many miles of country with festoons of this creeper everywhere, yet I never once came across a leaf punctured in any form whatsover, nor could I obtain the slightest indication of a species of Helopeltis living on that plant. In passing it may be said that, as a botanist, I was much disap- pointed with the Nambar forest. It might almost be described as an impenetrable expanse of some ten or twelve species of lofty trees with a dense undergrowth not very much more varied in character. The soil is, however, remarkably rich and in some parts would be very suitable for tea should an expansion in that direction take place in the future. ii. Nag a Hills. From Dimapur I passed to Kohima, and had during the ascent repeated opportunities of studying purely indigenous tea that is to say, tea regarding which no suspicion could arise (as undoubtedly exists in the case of the plains of Assam) of its being the survival of ancient Native cultivation. It was found on a rich red clayey soil, very similar to the soils in all the more successful gardens of the plains and curiously enough in association with wild Sa trees (Albizzia stipulata) and stunted bamboos. But what struck me as most significant, I failed absolutely to find any trace of Mosquito, Green-fly, Red-spider, Blister-blight, Red-rust, Grey-blight, Thread- blight, etc., etc., on the wild tea. In fact, with the exception of the older leaves bearing certain lichens and epiphytic fungoid organisms (which are also found on the tea in cultivation near jungle), I could get no trace of any of the pests and blights of the cultivated plant. The stems of the older plants, just as in old tea gardens and seed- gardens, were densely coated, however, with grey lichens. These may TOUR in ASSAM. Pan Leaves. Conf. with para. 543. Naga Hills. Sa Tree. Conf. with para. 86. Absence of P?sts on wild Tea. Conf. with laras. 45-49, 86, 3%0. Peport of Investigations in Assam Extent of Personal Explorations. TOUR AS&M. Return to Nazlra. Dibrugarh. be spoken of as epiphytes, and I think are very unwisely regarded as maladies. At all events, much unnecessary trouble is expended by the planters in the removal of such like epiphytes, while other and far more serious blights are allowed to do incalculable harm.* The grey lichen-coated stem is by most planters spoken of as " hide- bound." But it is a natural indication of age or want of vigorous growth, and if associated with declining yield is a consequence, not a cause of deterioration. All old tea will become lichen encased, and in the wild state the tea plant is more uniformly coated with these epiphytes than is the case almost with any other plant of the jungles in which tea occurs. If lichen or " hide-bound " be therefore a disease of the cultivated tea, every wild tea plant is so diseased, and indeed it might almost be said that the condition known as hide-bound is the only disease of the wild tea plant. From Kohima I marched north through the Naga Hills to Wokha and Mokokchang until I emerged from the hills once more at Gileki. 12. From the ist to the i2th of June I re-explored some of the gardens around Nazirain order to check the experiments that I had instituted, and to note the changes that had taken place during the interval of about six weeks of my absence, and on the 8th Tune I visited Behubar. 13- On the 1 3 th June I proceeded by small steamer down the Dekho river and thence by mail boat to Dibrugarh. 14. Di6rugarh.-QK the 15 th I commenced my exploration of ie gardens of Dibrugarh by going to Khonikor, and on the i6th made a passing visit to Chaukidingi ; iTth, i8th, and i 9 th were spent at Pamtola with excursions to a good many of the other gardens in that neighbourhood; 2oth, 2ist, and 22nd, Makum (Margherita) 23 rd, went down the river to Namsang; a 4 th, Jaipur and other gardens; 2 5 th and a6th f Ting ri, Bali Jan and other gardens ; 2 7 th Dum Duma; 28th,Talap; 2 9 th and 3 oth, Dum Duma (and out- gardens) also Sukerating. July ist returned to Panitola and pro- ceeded to Dibrugarh on the 2nd. Tea Pests and Blights. Extent of Personal Explorations. 15. North Lakkimpur. Through the kindness of the Jokai Com- pany I proceeded on the 3rd July, on board their steam launch, to visit some of the gardens of North Lakhimpur. Explored Bordeobam 5th, Patalipam 6th and 7th, Dirpai 8th, but owing to the floods on the Snbansiri river, was unable to visit Other gardens of this locality, and accordingly returned on board the Jokai steam launch to Biswanath Ghat. 1 6. Biswanath. On the nth July I inspected Gopesadarhu ; 1 2th, passed through Pertabghur and Bor Phukri spending a few hours in each; i3th, Mijikajan; uth, Giladharee and other gardens near by ; 1 5th, returned to Biswanath Ghat, thence to Silghat by mail steamer and that afternoon inspected Koliabar. 17. Nozvgong. On. the morning of the i6th I drove to Kellyden and spent some hours there, reaching Salonah late in the afternoon. The iTth was spent at Salonah, with a visit to Amluckie in the after- noon. On the 1 8th I drove back to Silghat visiting on the way Salol and Seconee. 1 8. Tezpur.On the i8th July I arrived at Tezpur and spent the 1 9th at Borjuli and Sonajuli ; 2oth, visited Hathibari and Nahorrani; on the 2ist returned to Tezpur and reached Calcutta on the 2 5th July. TOUR in ASSAM. North Lakhimpur. Biswanath. Nowgong. Tezi Report of Investigations in Assam Indications of Deterioration. Unsatisfac- tory Extent of Ground Covered. Co-operation of Planters. Con/, with. PIITOS. 24, 311(6). CHAPTER II. INDICATIONS OF DETERIORATION. Con/, wtih Deterioration, pp. 15B-16O. III. Some General Considerations on Results Obtained. 19. Unsatisfactory Nature of the Explorations. It may as well be stated here pointedly that my visit to Kangra was unsatis- factory. I reached the tea gardens too late in the season for seeing the most serious blights. Kangra, moreover, is so free from blights that I would have been in a better position to benefit by my inspection of these gardens had I reached them after having explored the larger and more important centres of the tea industry, instead of com- mencing operations there. The lessons to be learned from Kangra are more negative than positive, namely, the absence of all the impor- tant blights. I shall have occasion, however, to allude in further paragraphs to the pests that were actually met with in Kangra, but it may be stated that the present report is mainly based on my researches in Assam. It will also be seen, from the statement above of my move- ments in- Assam, that as much ground as possible was covered, during the brief term of my visit to that province. The time allowed me was far too short to admit of any very practical results being attained or scientific experiments performed. Through the kindness of the planters, however, I was enabled to cover on an average from 15 to 20 miles of road travelling daily (in passing from one locality to another), not including the 5 or 6 miles accomplished on foot while inspecting the gardens and hunting for blights. It may further be added that with very few exceptions I never stayed more than 24 hours at any single garden. Though necessarily of a very desultory nature, a certain amount of experience was gained, in thus rapidly inspecting a fairly charac- teristic set of gardens throughout the province, and of discussing with practical men the many problems of tea-planting that hinge on the subject of blights. I desire, however, to repeat that the present report is submitted chiefly in the hope that it may serve as a basis for more satisfactory operations in the future. The obvious defects of a panoramic view of the problems here reviewed, lies Tea Pests and Blights. Indications of Deterioration. in the fact that a garden visited in March or April may manifest a condition of affairs entirely dissimilar to that which would prevail in July and still more so in September and October. Moreover, I am assured that the Spring of 1895 was taken as a whole an abnormally bad one for blights of all kinds. Conclusions that are scarcely justi- fiable by fact are likely, therefore, to be occasionally and unavoidably arrived at on certain subjects, particularly the distribution and seasons of appearance of disease. But such defects may readily enough be corrected in the future, by the vast amount of experience and knowledge that exist, being pieced together, speculations dispelled, and a final report framed that would undoubtedly be of practical value. With the success that has attended the efforts to battle with similar maladies in other branches of agricultural and horticultural enterprise before us, it is no sanguine expectation to affirm that none of the pests and blights of tea, need be regarded as incurable or incapable of being averted. Indeed the wonder is that with so much talk of blight- proof wheats, blight-resistant potatoes, Phyloxera-free vines, etc., etc., no tangible progress has been made in that direction with the tea plant. IV. Treatment of Blights and Pests. 20. Imported Insecticides. The outcry has come from the tea districts for cures without any definite steps having been taken to ascertain the nature of the maladies to be cured. The response has been the supply of certain well-known patent and other insecti- cide preparations which the planters have been urged to " try." They have done so at considerable loss of time and money. When it is recollected that an acre of tea may contain 2,500 plants or even more, and that most gardens average 500 acres, the larger concerns owning 2,000, 3,000 and even 10,000 acres, it will be seen how impracticable hand syringing with insecticide fluids must be, even should the poisons employed be quite effectual in killing the pests. Were the entire labour force of a garden to be armed with syringes, the whole estate could not be syringed for many days. By the system of syringing limited plots daily, the portions so syringed become very nearly as badly affected as ever before the whole garden can be overtaken. Moreover, the blights of greatest moment occur when all hands are required to pluck the leaf and when stoppage of that operation for even a few days (in order to syringe) might mean not RESULTS : Unsatisfac- tory. Seasons of Pests. Pests Curable. TREATMENT of BLIGHTS: Insecticides. Difficulty in Syringing. 10 Report of Investigations in Assam Indications of Deterioration. TREATMENT of BLIGHTS : Insecticides. Poisons. Useful in Early Stages, Chiswlek Soap. Con/, with paras. 736, 742. only the loss of the flush then on the bushes but possibly a permanent injury to the flushing power of the garden for the rest of the season. But of course a severe outbreak of blight would no doubt materially reduce the necessity for plucking and thereby liberate a certain amount of hands for insecticide operations. In my opinion, however, insecticides are in the majority of cases impracticable and the labour charge in most cases too great even when, as in the case of an infusion of Adhatoda Vasica, the insecticide would cost next to nothing. Were it possible to run carts between the rows of bushes and to thus use larger and more powerful syringes than can be employed by manual labour, the case might be different. But there arises still another consideration, namely, that most, if not all, the insecticides in use are poisons and some of them even contain arsenic. It is all very well to say that the plants so syringed need not be plucked until after the fall of sufficient rain to wash the leaves clean. But were an insecticide of this nature extensively employed, it would by no means be improbable that some of the poison might find its way into the manufactured tea, moreover its use would undoubtedly endanger the lives of the coolies, and it might even poison the tea bushes them- selves. It is quite true that " Paris Green " and " London Purple " have been found effectual in killing certain blights, but it may be said that in no other edible crop* are the leaves the commercial com- modity, and therefore that the danger in the use of arsenical pre- parations is ten -fold greater with this than with almost any other crop seeing that the blights are nearly all leaf diseases. But while such views may be advanced on the subject of an extensive use of insecticides, it should not to be inferred that they are useless in all cases. On the contrary, if employed in the early stages of certain maladies, insecticides very possibly might avert the severity of attack. Sulphur, for example, has been used with success apparently on red-spider and the Chiswick Soap is claimed by its manufacturers to be a cure for all the more serious pests. But I have no practical experience with these or any other insecticides, and mention them simply because of their having been so loudly com- mended in certain publications. An unfortunate point remains to be added, however, that with mosquito, green-fly and even red-spider, * Except perhaps Pan and Mulberry. Tea Pests and Blights. ii Indications of Deterioration. the pests have advanced so far before being detected that they have even then passed beyond the stage of mitigation. 21. Indigenous Insecticides. Before concluding these gene- ral observations on the treatment of blights, and more especially on the subject of insecticides, I have to admit that prior to my visit to Assam I was in hopes an infusion of the leaves and twigs of Adhatoda Vasica might be found an effectual remedy against some of the more serious insect pests. The experiments performed by me in Assam convinced me, however, that, while it paralysed the mosquito, it did not act as a direct or immediate poison to that insect. But even had it proved effectual I am now satisfied that it would have been impracticable not merely because of the reasons already ad- vanced against all insecticides, but also owing to special considera- tions. The mosquito is an extremely active creature and withal remarkably timid. The slightest disturbance to the bush, and the adult or perfect insect flies off, while the immature or wingless ones probably drop to the ground or at all events disappear into the recesses of the crowded central portions of the bush. It is thus very nearly im- possible to bring the insecticide into contact with the mosquito, short of absolute submergence of the bushes, and even were that possible the adults would temporarily fly away only to return again with the renewed vigour of whetted appetites. It may be argued that the leaves, with the poison on them, would accomplish the object aimed at, on the return of the insects. Quite so, but that implies that the leaves should be so impregnated with the poison that they could not be used in the manufacture of tea. A poison which would remain on the tea bushes for some days should most certainly be guarded against, since the poisoned young leaves would stand a good chance of being plucked. With red-spider Adhatoda proved very successful, but not more so than a decoction of muddy water or water impregnated with cow-dung This tiny insect lives on the upper surface of the leaf, is immediately killed by the Adhatoda solution no doubt, but the forcible syringing with pure water has very nearly the same effect. The objection to Adhatoda is the same as to all other insecticides, viz., the impossi bility of reaching every leaf when, within a few days from its first ap- pearance, this minute creature may be found to have covered the whol tea area. The reader will find further particulars regarding red-spider and the methods of dealing with it, in the special chapter below devotee to that pest. TREATMENT BLIGHTS : Adhatoda. Mosquito. Con/, with para. 6S9. Red-spicier. Con/, with para. 749. Report of Investigations in Assam Indications of Deterioration. TREATMENT of BLIGHTS : Adhatoda on Mosquito Gfl Poisonous Fern. Con/, with paras.95, While, therefore, my personal experiments with Adhatoda on the tea blights have proved disappointing, the reports I have received from many planters have been more encouraging. In one of the gardens visited in North Lakhimpur, the superintendent assured me that, while he failed to discover that Adhatoda averted or lessened the attack of mosquito, a plot of badly affected green-fly tea had been completely freed from that pest by its use. He also assured me that in one of the gardens under him white-ants had appeared to an alarming extent. About 2 to 3 gallons of the Adhatoda solution had been poured on each bush near the stem with the result that the ants were killed and the bushes immediately showed marked signs of improvement. 22. Adhatoda is easily cultivated ; a plot of land of 10 to 20 square yards, with the cuttings one foot apart, would afford an abundant supply for all possible needs. This would cost next to nothing. I am, therefore, constrained to urge that, until a more trustworthy body of evidence has been obtained than we at present possess, the use of this insecticide should not be abandoned. Those interested in this subject will find Mr. D. Hooper's Hand-book (Imperial Institute Series) on Adhatoda, convenient and useful. Owing to my being editor of the series, under which it appears, I have contributed certain details to Mr. Hooper's Hand-book that might otherwise have appeared in this report, but which need not now be republished. The poorest soil available, especially abandoned village sites should be selected for Adhatoda cultivation. In addition to being a useful insecticide the plant has a high manurial value that should commend it to the attention of planters even were there no other considerations. 23. On more than one occasion I was shown a fern one of the commonest road-side plants in Assam known to be poisonous *and a decoction of which had been found an effectual insecticide against some of the tea pests. I had not an opportunity of trying this myself, but was assured by two or three planters independently both in Sibsagar and Dibrugarh that they had used it with much advantage. There are in fact many indigenous and abundant plants in Assam that are known to have insecticide properties, and where such preparations are desired I would recommend the use of locally manufactured insecticides to any patent chemical substance of a mineral and inorganic nature, * Nephrodium aridum, Baker. Tea Pests and Blights. Indications of Deterioration. more especially articles poisonous to the higher forms of life as well as to the blights. But in all cases infusions of insecticides should be made up with soap in order to assist in their adhesion. 24. Agricultural Reforms. From the remarks just offered it may be inferred that, as one of the practical outcomes of my Assam explorations, I have been compelled to realize that remarkably little value can be placed on insecticides. In fact, until we have deter- mined the life history of each pest, so as to be able to attack it with poisons, where these are indicated, at the weakest stage of its existence, I regard the promiscuous use of insecticides as pernicious. They certainly result in much loss of interest, and tend to give a feeling of satisfaction that is destructive to further effort. A much famed insecticide has been tried, has proved a failure and therefore nothing further need be thought of. The scheme proposed by this successful planter and that, has been pursued with avidity by his neighbours, only to be followed by a deepening conviction of the futility of averting what must after all be endured and placed against the financial successes on the other side of the record of the garden's operations. The process of trying effects is one of blindly groping in the dark so long as we have no grounds for our experi- ments. And this state of affairs, as it seems to me, has come about more by accident than anything else. The planters have only to be pointedly told that their co-operation is indispensable to any solution of the complex problems of the tea pests and blights, to ensure a large body of willing and careful observers." The time and money spent in trying experiments with insecticides had far better be directed to an intelligent effort to trace out the habits of pests. 25. Experiments that should be performed in every district. Why should we, for example, be unable to say where red- spider hibernates ? Some half a dozen simple experiments, extending, perhaps, over two or three years, would solve that point. Is there any occasion that half the planters should say they believe the mosquito hibernates on the tea bushes themselves, while the other half hold that the insect migrates to the jungles for that purpose. Surely, if a few bushes were completely enclosed by fine wire gauze frames, care being taken that some 20 mosquitos or so were placed within each, the return next year of the pest to the bushes or the freedom of the bushes from the blight would remove all doubts on that point. TREATMENT BLIGHTS : Soap. Con/, with para. 736. Agricultural Improve- ments. Life Histories of Blights. Co-operation Indispensable Con/, ivith paras. 19, 317 (6). Necessary Experiments. Cow/, with paras. 1O8, 274, 277. Hibernation Red-spider, of Mosquito. Report of Investigations in Assam Indications of Deterioration. TREATMENT BLIGHTS. Stunted Blight. Scientific Investiga- tions. Conf. with para. 318. Consequence not Cause. Defective Cultivation. Conf. with paras. SO, 43, 45, 51, 64, 92, 1O6, 166, 186, 197, 255, INFLUENCES The Wild Plant. Conf. with paras. 186, ISO. So again the majority of planters maintain that green-fly causes the " stunted blight," but a few hold a very different opinion. Personally I failed to prove the action of the green-fly, but my experiments were unsatisfactory. Need there be any doubt on that point ? Two or three bushes, in remote portions of the garden, some that had been severely pruned, others not (but none showing any trace of " stunt " at the time) have only to be carefully enclosed by very fine wire gauze or better still muslin, then a supply of the fly added, when a flood of light would be thrown on the disputed point. Such experiments and many others, if performed independently by planters in different parts of the country, would afford the data upon which might be framed a rational scheme of treatment for the pests and blights. 26. But I have seen such diversity in the behaviour of most of the diseases of the tea plant that I have had forced upon me the con- viction that many of the pests and blights of Indian tea should be relegated to the position of consequences rather than causes of the unhealthy state of the bushes. Where gardens or portions of gardens have been treated liberally and rationally, I have seen remark- ably few blights. I could mention many examples of one garden infested with every possible malady, while, hardly a mile off, the outskirts are reached of another garden of equal age, identical soil, exactly similar jat of plant, but enjoying an almost complete immu- nity from blight. Such examples I think very nearly justify the opinion that in addition to exhaustion from age (discussed in another chapter, pp. 155-160) there is an even more serious danger defective cultivation so that many of the tea pests and blights will have to be dealt with by changes in the systems and principles of the agricul- tural operations pursued. Few planters will refuse to admit that cer- tain plots of their gardens are unhealthy, and that the plants are pre- disposed to the attacks of what may be called external maladies. F. Influences of Cultivation. 27. Botanical Characteristic of Wild Tea.-It has already been stated that the diseases of the tea plant have very largely originated through cultivation. In the wild state the so-called Assam indigenous tea plant may be described as a somewhat remarkable large bush in exceptional cases it might even be called a small tree. It rarely forms a pronounced stem, but gives off near the ground, say, Tea Pests and Blights. Indications of Deterioration. from 2 feet upwards, three, five, or as many as ten branches which ascend and are sparsely, though similarly, branched, so that the tall narrow bush of 20 to 50 feet in height becomes not unlike a minia- ture poplar tree. It fruits freely on last year's wood (or near the extremities of the twigs) and the fruits are i, 2, 3, or 4 seeded with occasionally two seeds within each section of the fruit. The leaves are for the most part not more than 3 to 4 inches long and i| to 2 broad. They are of a dark green colour, concave on the upper surface, that is to say, the sides of the leaf ascend slightly so as to form a depression towards the mid-rib. The margins are sharply serrate and the apex considerably elongated. The veins of the leaf when examined by transmitted light show eight primary branches (on either side of the mid-rib) and eight subordinate veins. The veins of one side very nearly alternate with those of the other. The first pair and the last pair are very minute. These sixteen veins arch upwards in loops that unite together a little within the margin. There are often still more subordinate ramifications seen in some forms of the plant, but only the veins that form the loops here mentioned should be counted. 28. Races (Jats) of the Tea Plant. The number of the veins is a fairly constant and an interesting feature of the various forms of the tea plant. Thus, for example, it will be found that in the so-called China tea plant, only eight veins loop round in the way mentioned, and in hybrid teas there may be nine, ten, eleven, twelve, thirteen, or fourteen pairs. I do not advance these statements as applicable to every leaf that may be plucked off a tea bush, but I do affirm that the vast majority of the leaves of the " pure Assam indigenous plant " will be seen to have sixteen pairs of veins, " good hybrids " will have from twelve to fourteen, and all " bad hybrids " less than that, while the majority of the leaves of " pure China " will have only eight veins or sometimes even fewer. The " Manipur plant " (and the " Cachar " stock which may originally have been derived from the Manipur) has more than sixteen pairs of veins. In some cases twenty-two veins may be counted. But the Manipur plant has altogether a larger habit than the Assam. 29. Peculiarities Produced in the Garden. According to botanists all forms of the tea plant belong to one species. Whether we are to regard the Assam form as a natural race (shall I say variety) distinct from the Manipur or not, cultivation can be seen to have INFLUENCES of LTIVA- ~ON: The Wild Plant. CUL1 TI( Veins of Leaf. Conf. with para. 8O. Recognition Cultivated Forms. Conf. ii-tth para. 7%. Assam Indigenous. Conf. with paras. 49, Manlpur. The Garden Plant. 16 Report of Investigations in Assam Indications of Deterioration. INFLUENCES CULTIVA- The Garden Plant. China Plant in Kangra. Flashing. Con,/, with para. 2O6. Igin of Con/, with fara. 66. produced even greater departures than exist between the very small thick-leaved China stock and the large soft leathery-leaved Manipur plant. Setting on one side the botanical problem here indicated, attention may be directed to the subject of the changes in the charac- ter of the tea plant, under the hands of the planter. When grown for its leaf-flushing power it is a bush not more than 4 to 5 feet in height. In some cases a short thick stem, from 4 to 9 inches in diameter and 2 feet in height, has been produced ; in others it has been made to branch very early into a skeleton of five or six main branches, each perhaps 2 inches in diameter ; and in still another condition a broom of a perhaps 50 to 100 shoots not thicker than the thumb have been made to ascend from the ground parallel to each other to a height of 3 or 4 feet. In all these cases the plant has lost its natural habit of a sparsely branched tall bush. The China plant of the Assam gardens is for the most part a low, much-branched bush which only very occasionally is seen to have a distinct stem. In Kangra, however, it is often tall, erect, and very much more like the hybrid than the China plant met with in Assam. But in addition to a complete change in primary structure or form, it has become densely covered with a multitude of minute branchlets that bear leaves nearly twice the size of the average leaves of the wild plant, and in the better jats of Assam indigenous these are pale coloured, soft, less distinctly serrated and concave below. It has to a large extent been deprived of the power of flowering and fruiting,* its whole energies have been concentrated in the flushing or production every seven to ten days (during part of the season at least) of a complete new set of shoots that each bears a terminal bud and three to seven leaves according to the system of plucking that may be pursued. Not only have the leaves become soft and pale green, but, together with the whole of the young shoots, they are very succulent and only slightly lignified. 30. Origin of Disease. The entire nature of the plant has been changed. It is of course grown for its young leafy shoots, and success depends on the quantity and rapidity with which these are formed. There is reason to believe that in the early years of tea * Indeed it is considered (and very justly so) an indication of a dege- neration, from the planter's standard of a good bush, when it shows a tendency to fruit ; the fruits are promptly removed in consequence, but I fear the act of removal could hardly be an effectual cure for this tendency. Tea Pests and Blights. 17 Indications of Deterioration. planting, the Assam indigenous afforded only some four or five flushes* during the season. It now yields on an average from 20 to 30. And if this fact alone does not appeal to most planters as denoting a radical change in the plant, the well-known further fact may be added that for some years past it has been observed that mid season in all good jat gardens at least is gradually becoming later. I am aware that some planters think this is due to the plants not being so severely plucked in the early months of the season, a change of practice on that point having taken place owing to the more extended cultivation of Assam indigenous. There may be some truth in that, but still there would appear no doubt the period of the plant's activity is being altered in adaptation to climatic changes (consequent on the opening out of large tracts). It may seem paradoxical, however, to say that success consists in the production and development of a diseased state, but such is the case. The fattened ox is in reality an animal in a condition of disease, quite as much so as blanched celery is a diseased vegetable product. In both cases they could not exist but for the protecting care that is bestowed on them. In other words animals and plants are, strictly speaking, diseased whenever their natural functions are disarranged. In such a condition they can exist when carefully tended only. It might, however, more correctly express this view of the case to say they are in an unhealthy condi- tion and to thus reserve the term " disease " to the specific ailments that supervene. They are, in other words, living in a state of predis- poaition to the organic diseases that may ultimately effect their destruction. 31. This is true of course of nearly all cultivation, is in other words an expression of the effects of domestication. But it is doubly true in this case. The tea is forced to produce an abnormal or disproportionate amount of leaf ; it has been practically refused the rest given after fruiting ; and it has been removed from the shade of the forest and association with other plants. Indeed it seems very likely that the so-called rest that the plant gets in winter is more than obliterated by the annually recurring effort that is required shortly thereafter to recover the severe shock of the pruning (and probably also the deep hoeing) to which it has been subjected. * See Bruce's Reports. INFLUENCES of CULTIVA- TION. Origin of Disease. Mid Season. Diseased State. Disease a Consequence of Cultiva- tion. Predisposi- tion. Conf. with par. -is. 44, J7, 73, 226, 282, 345, Domestica- tion. Winter Rest. i8 Report of Investigations in Assam Indications of Deterioration. INFLUENCES CULTIVA- TION. Renewal of Stock. Perennial Crops. Old Tea Bushes. Renewal by Filling up Vacancies. Old Gardens Soil Exhaustion, Con/, with paras. 38, 54, 108, 114, 128, 144, 157. 32. Renewal of StocJe. The stock would undoubtedly be healthier were the tea plant allowed to fruit and die after the lapse of so many years, fresh seedlings being made to take the place of the older and exhausted plants. There can be little doubt that such crops as jute, indigo, and wheat, crops that are renewed each year from seed, are by no means so predisposed to disease as are perennial crops grown on the same soil from year to year without any rotation or change in stock. It follows that success in tea-planting must in the end lie in the direction of safeguarding the plant against its predisposition, and that accordingly with the vast majority of the pests and blights prevention must be infinitely better than cure. But the undoubted vitality of the tea plant is such as to have ob- scured the value of these truisms. Gardens can be pointed out that have given excellent results for thirty or forty years, and a few planters have even assured me that they were convinced such gardens may be expected to continue to do so indefinitely. The superinten- dent of one of the largest concerns in Assam writes me that in his " opinion old tea when properly treated does not deteriorate." There are, however, many difficulties in the way of trustworthy statis- tics being compiled on the subject of the possible deterioration of old gardens. Though the manager very likely knows the actual yield of each separate plot, the published returns express the averages for the whole estate. Few gardens are of one age throughout, the majority have had and are now having, new plots added to their leaf-yielding area every few years. Moreover, it would be hard to say that all the plants in any single plot of, say, 20 years' existence were of one age. The habit of filling up vacancies is believed in and carried out by a great many planters. In fact in many of the old gardens there is reason to believe that this practice has been followed and to such an extent as to have practically renewed the greater part of the so- called forty-year old gardens. The question for the moment may be said to be not one of whether the Assam soil is capable of bearing tea for 40 or 400 years, but exclusively one of the power of endurance of the individual plants. It will be seen under the Chapters below on Drainage and Manures and Manuring that I fully recognise soil exhaustion as an equally serious danger. I have been taken over many estates where no hesi- tation has been shown in making the statement, " This Company is Tea Pests and Blights. Indications of Deterioration. practically saved by one of its out-gardens a bit of excellent lane which six or eight years ago was put under the finest Assam Jat.' I am not aware of having been taken over a blighted garden or an inferior portion of a garden, without the apology having been given me that it was "An old garden," a "Neglected bit," or a "Piece ruined by a previous manager." But if the old gardens have done so admirably and have such capabilities still in them, why have we al this outcry for permission to interline and then uproot or for exten- sions into new areas ? Is all that purely and simply the result of the vastly superior yielding power of the " Assam indigenous ? " Is there no danger that the plant which stands at present so high in popular favour, after a term of, say, forty years' bearing, may be found inferior to the Burma, Lushai, Japan or some other new favourite ? While not desiring for a moment to throw doubt on the merits of the Assam plant, it may be asked, Is it safe to affirm that no element of the present outcry should be assigned to a very natural deterioration which has taken place as the result of so many years' compulsory leaf bearing ? If deterioration be admissible, the much-talked-of blights might be viewed as very largely referable to the position of consequences of the present system of cultivation. It can be shown that in most gardens there are maladies present, less visible, it is true, than the visitations of the mosquito, but which are nevertheless permanently injuring the bushes. The effects of these diseases can easily be demonstrated. 33. All well established new gardens admittedly give better results than old ones. This, as already indicated, is doubtless largely due to a better and more productive /#/ or stock being planted out in the new gardens than exists in the older ones. But I was shown over many gardens of the very finest jats of tea, the yield of which had declined. I did not come across a garden badly blighted that gave the opposite record. And, with the exception of one or two of the blights and more especially in cases where these blights had only recently ap- peared to any serious extent, I did not find a garden in Assam badly blighted in which the bushes did not show that they were in an unhealthy state, apart altogether from the peculiar malady with which they were at that particular time beset. 34- There would appear to be no doubt that the number and se- verity of the tea blights are in the ascendant, and more especially in INFLUENCES CULTIVA- TION: Old Gardens. New Races. Deterlora. tion. Conf. ^v^th paras. 271- Blights In the Ascendant. Conf. with para. 166. Unhealthy Bushes. Conf. with para. 166. 20 Report of Investigations in Assam Indications of Deterioration. INFLUENCES CULTIVA- TION: Unproductive Gardens. Old versus New Gardens. Con/, with para. 274. Procrastina- tion Dangerous. Collar Pruning. Conf. with paras. 185, 193,211, 215-25, 872. VEGETABLE BLIGHTS. Coffee-Leaf Disease. For Several Years was Harmless. Conf. with para. 276. the old than in the new districts. But I speak here of the blights col- lectively, for I am fully aware of certain pests that attack the finest and youngest tea. These pests are doubtless alarming, but their ul- timate effect on the production of the estate is not to be compared with the hundreds of acres that give returns hardly commensurate with the expenditure on them and which are shown to the visitor with an apology for their shortcomings. Personally I would rather own a vigorous garden that was shut up for a few months a year by some en- demic pest than one in a chronic state of semi-unproductiveness. The battle against the former is one in which victory must in the end be with the intelligent cultivator, the latter has but one rational course before it extermination and replanting. 35. It is next to folly to expend money and time in the vain hope of coaxing old, diseased, and unproductive gardens into a state of productiveness. In some cases renovation of the bushes no doubt can be brought about by " collar pruning," but if the stock chanced to be bad originally interplanting better jats and uprooting the old bushes would in the end be found more satisfactory, provided the soil has given no indications of exhaustion. I do not go into the question here of the advantages of renewal of stock or filling up of vacancies versus extension into new clearances. My present intention is to exemplify the conviction I formed in Assam that by far the most serious dis- eases are those which slowly but surely and permanently reduce the productive power of the bushes and ever hold over the industry the warning of the Ceylon coffee disease against procrastination in their treatment. VI. Vegetable Blights. 36. The Coffee-Leaf Disease is a fungus that first had attention directed to it in 1868. Prior to that, according to the reports that exist, it had been known to the planters but \vas not regarded as of any serious consequence. Indeed NietneP, who described some 28 insect and other animal pests of the coffee plant, adds in a sub- sequent revision of his report, that he had known it for several years, but that it never did any material harm to the coffee until lately. For this reason it was not included in his Observations on the Enemies of the Coffee Tree. In my opinion we have similarly been giving a disproportionate amount of attention to the insect and other pests of the tea plant, to the utter neglect of the fungal blights. In 1869 the Tea Pests and Blights. Indications of Deterioration. coffee-leaf disease received the name of Hemileia vastatrix anc it is curiously interesting, as indicating, the mysterious way in which many of the better known fungal blights of crops have made their appearance, that when first examined by the Rev- Mr. Berkeley it was then quite new to science. There was experienced in fact some difficulty in assigning to it a definite place since it was found inter mediate in its structural peculiarities to two of the chief groups o parasitic fungi previously known. Though searched for in the neigh- bouring jungles for some time, the late Mr. Thwaites failed to find i on any of the allied plants to the coffee. It certainly could not have been a prevalent fungus in Ceylon before it appeared on the coffee since Mr. Berkeley informs us he had examined more than one thou- sand species of fungi from Ceylon without having had sent to him a specimen of this curious parasite. In 1871 it was, however, discovered on the wild coffee of Ceylon, Coffea travancorensis, but whether it had spread from that plant to the cultivated coffee unobserved or had gone in the opposite direction has never been satisfactorily ascertained. In 1878 the Rev. Mr. Abbay read a paper on the subject of the coffee-leaf disease before the Linnean Society which, as afford- ing some useful warnings against any neglect in the treatment oi the fungal diseases of the tea, may be here briefly reviewed. " A first, he says, the ' disease ' was regarded by those best able to judge as a temporary one, which would run its course for a year or two and then disappear as mysteriously as it came. This view was strengthened by the apparent departure of the pest when the rainy monsoon came on ; but with the return of dry weather it re-appeared, ct of the disease presently became apparent in a diminution jit which the tree yielded; and in 1872 the matter was re- xs serious. Previous to, and including, 1871, the average five years over the whole island had been 4-5 cwt. per 1st for the five succeeding years the average had only been ' In 1878 the yield became less than 2 cwt. an acre and the annual loss was estimated at ,2,000,000. "Since the ' made its appearance in 1869, the enterprise has suffered to ' of fro.m ji 2,000,000 to / 15,000,000 in crops alone ; yet I ^re is not a single recorded instance of a tree having been le pest." For coffee-leaf disease see Professor H. Mar- 8 report published in 1881. 22 Report of Investigations in Assam Indications of Deterioration. VEGETABLE BLIGHTS. Tea Blights. Ever Present, Effect of Blights. Con/. w uh paras. 839. SO. 37. Some Tea Blights. What subsequently took place is matter of history and need not be dwelt on here. Without wishing to give this report on Assam tea a tone of alarm greater than the facts that I have been confronted with justify, I am bound to say, that there are fairly prevalent a few fungal blights and one or two insect pests, not hitherto recorded as of serious consequence, that in some respects establish a parallelism to the story of the coffee disease. They have most mysteriously appeared, with one exception have not as yet been traced into the neighbouring jungles, not even to the wild tea, and they are for the most part looked on as curiosities or have not even been recognized as blights. Unfortunately I hold a different opinion. They have certainly hardly as yet given prognostications of any one of them suddenly assuming gigantic proportions, but they are ever present enemies that are reducing the productiveness of the bushes upon which they have become established. I have on more occasions than one marched across gardens this way and that in company with the managers and counted along with them from 25 to 60 per cent, of bushes badly affected by one or other of these blights. They do not kill the bushes (no more than the coffee-leaf disease did at first), but within a few years the plots so affected have to be exhibited with an apology for their shortcomings. I could name a dozen or more gardens that have each a plot of from 50 to 100 acres of fine, large, well-formed indigenous Assam bushes, that a few years hence, if immediate and drastic measures are not taken, will be re- duced to distorted unhealthy stumps each bearing a few gnarled and unproductive branches. 38. And it is the neglect of such blights, very possibly more than anything else, that has brought about the change in productiveness of some of the older gardens. There are few gardens indeed in which one cannot detect here and there a plant affected by one or other of the fungal blights and minute pests to which I allude. In other cases they are more prevalent, particularly in certain plots, but fortunately in only rare instances are they to be found to the alarming extent I have named. I need hardly specialize here these blights, since further particulars will be found in the paragraphs below that deal with them individually. 39. Two parasites of this nature one a fungus, the other an alga may, however, be said to live on the bushes (if not removed) from Tea Pests and Blights. Indications of Deterioration. year to year and to annually destroy a large percentage of the twigs which ought to bear the flushing shoots. These are known popularly as " Thread blight" and " Red rust" (Cephaleuros virescens*). One, if not two, species of fungi live on the roots and extend from bush to bush until their presence is recognized by the death of a circular clump of bushes. So again three, if not four, serious blights attack the leaves for so many months a year and seem thereafter to leave the bushes altogether. These are "Blister blight" (ExO- basidium vexans) , " Grey blight," and a curious disease which I think must be accepted as a felt-mite (Acarus sp.), I have given to this insect pest the provisional trivial name of " Apple-foliage blight " on account of the more or less permanent structural changes which it effects on the leaves. 40. The last mentioned does not seem to have been recognized by the planters as a blight at all. The fact that the plants affected by it never flushed, had been observed by nearly every one. These plants have for the most part been regarded as sulking, though in some cases individual bushes had been observed for many years to have remained in the same state without giving a single leaf in return for the cultivation and even manure that had been expended on them liberally. I believe most of the gardens in Sibsagar district, where this disease seems to be worst, contain from one to five per cent, of bushes affected in the manner here indicated. But in addition to this felt -mite there are several species of blister-mites distributed all over the tea estates. The leaves are pale coloured and on the under side show multitudes of minute warts. 41. The term " Grey blight " I have given to a fungal leaf disease (Pestalozzia Guepini) of increasing frequency and severity that has been observed by many planters as doing considerable injury. It seems to have first appeared in the Dibrugarh district, but has within the past few years spread over the greater part of Assam, The leaves become blotched with grey patches on the upper surface. These commence for the most part at the base, more rarely the apex of the leaf, and extend until the whole surface is covered. Each leaf, as the disease advances, drops into contact with a leaf below, and where it so touches becomes fused with a woolly-like structure that * Formerly known to Indian Planters as Mycoidea parasitica. VEGETABLE BLIGHTS : Red Rust. Con/, with paras. 851- 874. 9SK Cow/, with paras. 818- 26. Con/, with paras. y59- Prevalent In Sibsagar. Grey Blight. COM/, with paras. 8O4~ Originated in Dibrugarh. Report of Investigations in Assam Indications of Deterioration. VEGETABLE BLIGHTS: Grey Blight wind Distributed. Blister Blight. Conf. with paras. 818- Bushes turn Blank. is seen to at once communicate the disease. The injury spreads rapidly until a zone of, perhaps, a foot in diameter has passed round the circumference of the bush. Not infrequently it extends upwards as well and the bush then becomes entirely denuded of its leaves. But curiously enough the action seems often to be suddenly arrested, so that bushes may be found partially or entirely denuded of their foliage or only a large patch on one side of them may be so affected. The malady appears also to be carried by the wind since across certain plots all the larger or exposed bushes become at first affected and on the same side. But this fungus not only destroys the leaves, it attacks the buds as well, so that when the bush throws off the attack and bursts into fresh activity, it is seen to have large gaps or holes, caused by the twigs that have perished. In some respects it resem- bles thread-blight, specially in the woolly attachment that communi- cates the disease, but there is no thread extending down the twigs, and the upper, not the under, surface of the leaf is invaded by the fungus. 42. "Blister blight," which at first I thought might not be of fun- gal origin, but possibly a gall-forming mite, allied to that which cftuses the blisters on the leaves of the pear tree (Phytoptus pyri) similarly attacks the leaves. There is, however, no doubt as to its being of fungal origin. It exists as large shining circular depressed blotches above, which below seem as if they were coated with white wool. When first seen it appears as a minute pink spot with a gradually expanding transparent pale green margin. In two months' time all the affected leaves and twigs turn black and die. The bushes then recover and the planter may be disposed to think the blight has disappeared and may even imagine from the renewed activity of the plants that it has done no material injury. At the same season, however, it will very possibly return once more and again close large portions of the garden, though it need not necessarily commence on the same bushes on which it first appeared last season. Of one garden I was told of two attacks, one in Spring, the other in Autumn. Can it, therefore, be said that ex- perience, in other parts of the world, supports the affirmation that since blister only appears in Spring it is not serious although it may close the garden for parts of March, April and May ? But even were this of no great consequence, have we any evidence that blister may Tea Pests and Blights. Indications of Deterioration. not change its habit and come at two or more seasons ? It has already been reported to have done so in at least one garden. 43. It will be seen, from the further particulars recorded below, regarding these animal pests and vegetable blights, that in the first instance they almost invariably attack tea of a particular kind or in a certain stage of growth. They have not as yet been found on wild, that is, indigenous tea in the jungles, and therefore there would seem no doubt they find in the cultivated states of the plant the peculiar conditions necessary for their production. There would appear abun- dant evidence that many of these diseases cannot in any way be treated with insecticides, but may yield to improvements in the system of pruning, more especially a change in the season of pruning, to suit special diseases. In some instances they are associated with imperfect drainage, in others occur for the most part in small confined plots surrounded with jungle, or bad ventilation, in still another con- dition, appear on young vigorous shoots in the early months of un- pruned tea. But the inference, as I have already said, seems to me unavoidable that in many instances the peculiar conditions of culti- vation and the character of bush and leaf, which the planter aims at producing, -are peculiarly the hot-beds of many of the most serious diseases of the tea plant. This statement will be again returned to and substantiated in the Chapters on Pruning and Plucking. VI I. -Insect and other Animal Fests. 44. The publication of this report has not been delayed until the scientific determinations of all the blights and pests had been accom- plished, because I deem the general principles involved by the study of these of even greater consequence. This defect compels me, however, to speak, for the present, in terms of uncertainty regarding some of these maladies. There would seem no doubt that the pre- valence and the wide distribution of most of the pests indicate that cultivation has produced a condition of predisposition to these attacks. This idea could not be more clearly established than by a study of the better known insect pests of the tea plant. It might, almost without fear of contradiction, be affirmed that the majority of the herbivorous insects of the Assam valley have shown, or are showing, a willingness to live on some part of the tea plant such as the leaves, buds, flowers, bark, root or wood. The great majority of these pests do so very 26 Report of Investigations in Assam Indications of Deterioration. ANIMAL PESTS. Common to Coffee and Tea. Mosquito-like .Puneturings. little harm, however, and have given so little indication of their ever being able to do much more injury than at present, that the interest in them centres mainly in the indications they afford of cultivation having altered or weakened very materially the nature and properties of the tea plant. 45. Common Pests of Coffee and Tea. Botanically tea is not so near related to coffee as it is to several of the indigenous bushes that are prevalent in the jungles around the gardens. Eurya japo- nica, for example, is not only a bush readily mistakable for tea, but it might be described as cousin to it. The coffee plant is not a native of Assam and is only experimentally grown in one or two gardens. There is, however, a wild species of the genus common all over the province Coffea bengalensis. The so-called wild coffee of many persons in Assam is a Morinda, and, therefore, not coffee at all. The indigenous coffee plant is leafless for more than half the year. I have examined it with great care, but never found on it any of the tea pests. Yet strange as it may seem, a very large percentage of the insect pests of the Ceylon coffee plant, as described by Nietner have been found doing considerable damage to tea in India. Few, if any, of these common pests of coffee and tea have as yet been traced to other plants in the Assam jungles, and the problem thus presented for solution is one of great obscurity. Insects, as a rule, are remarkably accurate botanists. In the jungles the majority will be found to confine their predatory habits to certain species of plants, sometimes even to certain varieties of a species, omnivorous insects (that is to say, insects that will feed on different plants) are met with more frequently under cultivation than in the jungles. The scarlet insect that has been alluded to as puncturing the leaves of Msesa indica is not likely to be found on any other plant. When eight or ten of these insects were confined on tea shoots, they re- fused to puncture them and most of the insects accordingly died of star- vation, the others recovered directly they were given a supply of their own peculiar food. I have examined carefully all the plants of the Assam jungles that are allied to the tea (such as Eurya, Schima,* etc., and even Camellia thea itself, in its wild habitat, but never succeeded to find any of the tea pests on these. Similarly I have looked at the bushes and herbs of these jungles that are allied to * See the remarks under the account of Mosquito, paras. 513-14. Tea Pests and Blights. 27 Indications of Deterioration. coffee, but equally failed to find on these the insects that have been recorded as common to both coffee and tea. 46. Nietner (The Coffee Tree and Its Enemies, Edition by Green, 1880) describes 27 insect pests on Ceylon coffee, and of these (or closely allied forms) some ten or eleven are found on tea in India. It may be of interest to record here the names of these correspond- ing Coffee and Tea pests. (1) Lecanium coffeae, Nietner (the brown scaly bug), found by me in North Lakhimpur, Nowgong, etc. (2) Lecanium nigrum, Nietner (the black bug) ; "said to occur in Kangra. And in association with these two bugs (just as in Ceylon) a black fungus is met with (? Triposporium Gardner!, Berk-} living apparently upon the saccharine secretions caused by these insects. (3) Aphis coffeae, Nietner, represented in Kangra and Assam by the allied insect Ceylonia theaecola. This curiously interest- ing creature occurs in every tea garden in Assam, and on one occa- sion I found it in the jungles feeding on Maesa indica. (4) Tetranychus bioculatus, W.-M. (the Red-spider), described by Nietner as Acarus coffeae. Found by me once or twice on rose bushes, in flower gardens, and on the flowering Camellia. Never seen in the jungles. It seems to have become diffused throughout the tea districts of the world. I found it, for example, in a new garden, in the Dibrugarh district, that has at least 20 miles of jungle all round separating it from other tea gardens. Could it have been imported by rose bushes ? (5) Zeuzera coffeae, Nietner. The Red-borer, common in Assam and Kangra, though in neither of these centres assuming alarming proportions. (6) Parasa lepida, Moore (the Indian form), described by Nietner as Limacodes graciosa. This moth exists in the larval stage as a stinging caterpillar of a greenish colour; and if not itself present in Assam one or two allied species take its place. (7) Agrotis? suffusa, Fabr. (representing the Ceylon coffee " Cut-worm," A. segetum), was found in one or two nurseries eating the roots of the young tea. The determination of this moth may be regarded as open to doubt. (8) Gracilaria theivora, Wlsm, This insect is common on the tea both in Ceylon and in Assam and is a pest of considerable ANIMAL PESTS : Common to Coffee and Tea. Brown Bug. Con/", with paras. 643- Fungl. Con/. iHth paras. 638-9, 801, 837-8. Black Aphis. Con/, with paras. 597- 610. Red-spider. Con/, with paras. 718- Red-borer. ConA with paras. 393- S tinging Caterpillars.. Con/, with paras. 399 Cut- worm. Con/, with paras. 451- 63. Leaf-roller. Con/, with paras. 462- 73. 28 Eeport of investigations in Assam Indications of Deterioration. ANIMAL PESTS : Common to Coffee and Tea. Leaf-borer. Conf. with paras. 491- White-ants. Conf. u-ith paras. 665- 710. Predisposi- tion. Conf. u-ith pnras. SO, 02, 826, 282 820. Indian and Colon Tea Pests. importance. The larvae in their early stage travel beneath the under- epidermis of the leaf, generally in the direction from the mid-rib to the margin. They then emerge and cause a fold of the margin, perhaps an inch in length and less than a quarter in breadth to roll over them. In a further stage they roll the leaf more or less com- pletely from apex to base, doing considerable injury to the tea where they are met with at all plentifully. (9) Oscinis these, Bigot. This is an extremely common insect in Assam ; in most gardens it is not difficult to find a bush that has one or more of its leaves burrowed by the larvae of this minute fly. The action appears to commence near the base of the leaf and is carried to the apex where the chestnut-coloured cocoon may be readily seen. (10) Termes taprobanes, Walker (the common white-ant of India), the T. fatalis of Nietner's Ceylon coffee pests, often does much harm to tea. 47. Doubtless when the study of the tea pests has been prose- cuted more satisfactorily than at present, other examples may be found. But those mentioned may be held as supporting the view that is here desired to inculcate, namely, that cultivation of the tea plant . (just as is the case of the coffee) has brought it into a condition of predisposition to the attacks of blights and pests. It is curious, how- ever, that two so widely dissimilar plants as tea and coffee the one grown for its leaf and the other for its seed should have resulted in bringing them into a condition favourable to so many pests in com- mon. This may of course be due to the active principle of coffee and tea being chemically so very similar, if not identical. 48. Common pests of Indian and Ceylon Tea. It is even more remarkable still that throughout the Indian and Ceylon tea areas so large a proportion of the tea pests should re-appear again and again in localities often remote from each other and which possess but little in common save the existence of the tea plant. Mr. E. E. Green has published in the Ceylon Independent several very admirable papers on the subject of the tea pests of Ceylon. These have re- appeared as a useful little book called The Insect Pests of the Tea Plant. Mr. E. C. Cotes, formerly an assistant in the Indian Museum, issued some two years ago, in the Museum Notes, a review of the literature of the Indian tea pests, in the possession of the Indian Museum. Tea Pests and Blights. Indications of Deterioration. The explorations conducted by me in Kangra and Assam have not only brought to light a large number of new tea pests, but have revealed the fact that a very much more extensive series of the Ceylon ones occur in India than was previously thought. Mr. Cotes, for ex- ample, describes some 40 species of tea pests, and of these 1 8 have not been recorded as met with in Ceylon ; two species mentioned by Mr. Cotes seem peculiar to Ceylon; and the balance are either mentioned by Mr. Cotes, as common to both India and Ceylon or are species hitherto recorded in Ceylon only but which, it will be seen in another chapter of this report, have now been added by me to our list of Indian tea pests. 49. When it is recollected that some of these, such as the mites, are so minute that they cannot be seen by the naked eye, the marvel is pre- sented not only of their existing both in India and Ceylon, but of their being capable of moving with rapidity from district to district within India itself. Mr. Green speaks of the mite mentioned below (which I take to be very possibly one of the species of mites recently found by me in India) as having been detected in certain Ceylon nurseries. Although not hitherto recorded in India a minute mite closely allied to, if not identical with, the species described by Mr. Green as Typhlodromus carinatus was found by me all but universal in Assam in association with another mite an undescribed species which I have called the pink-mite Phytoptus these. The latter is possibly the chief cause of the late flushing of the purer Assam jats of tea, and what struck me as significant, it had (like the red-spider) found its way to all the new gardens and in one case to a garden opened out only four years ago in a district where no other estate occurs nearer than 20 miles in any direction. I looked very carefully for this mite in the jungles around the tea gardens, but failed absolutely to detect it, though, from March to Jane, the characteristic pale green leaf of Assam indigenous te?, plucked from a very large proportion of the gardens, if viewed under a fairly powerful lens, would be seen to be literally siive with this very minute enemy to the planter. VIII. influence of Jats of Tea on the Development of Blights and Pests. 50. Cause of Late Flushing. -The circumstance mentioned above will no doubt come as a revelation to many planters, since the Indian and Ceylon Tea Pests. Mites. Migration of Purple-mite. Con/, with paras. 747- 6S. Pink-mite. Con/, with para". 7SO- 95. Late Flushing. Con/, with para, 785, JATS Of TEA in RELATION to BLIGHTS and PESTS. Report of Investigations in Assam Indications of Deterioration. JATSofTEA RELATION to BLIGHTS and PESTS. Slnglo. Bazaloni. Namsang, Pink-mite. Banjhi. Con/, with paras. 79, 1906, 83O. Cultivation : Effects of. Immunity of Manipur Stock. opinion that the pale colour of Assam indigenous was an indication of the high quality of the /a/ is all but universally held. I do not for a moment wish it to be understood that I deny that the Assam indigenous races collectively are not naturally pale coloured perhaps more so than the Cachar and Manipur, and I am not unaware that within the series of forms (or jats) designated " Assam indigenous" there are recognizable shades of colour. Singlo is for the most part paler coloured than Bazaloni or Namsang. But what I do contend for is that there is very commonly seen in gardens of Assam indigen- ous, a greater degree of paleness than is natural, and that this abnormal paleness is associated with exceptionally late flushing. It occurs more especially in seasons of drought and late rains, on plots of land that become flooded in the rains and caked in the dry weather, or that are too exposed and dry for Assam jats. The leaves will be seen to be not only pale green, almost straw-coloured, but to have a pink tinge, especially along the margins and veins. Later on in the season they become spotted, bronzed and very brittle, and, although they do not fall off, the bushes have been distinctly arrested in their growth and the buds even rendered unproductive or " ban- jhi" This state of affairs is undoubtedly caused by the pink-mite, and, although its presence has never before been recognized, it is in many respects a more serious visitation than the much-talked-of red-spider, because of its attacking the young tea and the better jats. 51. Though searched for carefully I failed to find the pink-mite on China tea or even on hybrid jats, unless when these approached very closely to the Assam types. Here then we obtain an indication that cultivation has not only changed the character of the tea plant, but that there have been produced special conditions that are more favourable to one set of blights and pests than to others, or it may be, that give a degree of immunity from certain diseases. I am not prepared to affirm thai the success that has been at- tained by some gardens, with Manipur stock, i s due very materially to the fact that I have found this mite much less frequent on the Cachar and Manipur jats of tea than on the pure Assam indigenous. Indeed I have reason to believe that the pink-mite is not unknown even in Cachar gardens, presumably of Cachar stock. But I hold emphati- cally that it is most unwise to purchase a particular jat of seed, on the high reputation ii enjoys, without reference to its suitability or Tea Pests and Blights. Indications Of Deterioration. otherwise to the conditions under which it is proposed to be culti- vated. We know enough to begin to piece together some elementary facts regarding each of the better known races of the tea plant, and among these should undoubtedly be included the liability of the Assam indigenous to the ravages of the mite here alluded to, on all soils that do not retain sub-soil moisture or that suffer from lateness of rainfall. 52. Hybrid more liable to Mosquito. So again the hybrid teas are known to flush early, are in many cases hardy, give a rich flavour to the teas, and yield favourable results in gardens where the purer jats have, comparatively speaking, failed, but my own observations confirm the very general report that mosquito makes its appearance first of all upon the hybrids. It is certainly remark- able that the newer gardens that possess next to no hybrids enjoy a comparative immunity from this by far the most serious insect pest of the tea plant. But in 1881, according to the late Mr. Wood-Mason, it was chiefly found on the China plant and had never been seen on the indigenous. It has since that date apparently changed its habit, for it may be found on all forms, though preferably on the hybrids. But in some gardens where it may be said to have only recently appeared, the mosquito still shows its preference for the China plant. 53. China and Hybrid first attacked by Red-spider. In a like manner red-spider appears first of all on China and poor hybrid teas, rarely on Assam. It is the first to appear of all the serious pests in point of date, and a concensus of opinion was given me that seemed significant, viz., that in the early part of the season it was first observed on the bushes near the lines or other buildings within the garden. I do not deal here with the practical considerations that may suggest themselves from that observation, since my present object is to endeavour to set forth the indications that support the opinion that certain/aft of tea are more liable to, or fyijoya comparative immunity from, certain blights. But if the illustrations already given be accepted as sufficient justification (and many more might be mentioned), then the affirmation may be made that some practical steps to improve the seed and, if possible, to produce blight-proof jats of tea, is one of the most imperatively demanded reforms of the industry. 54. Conclusion. Having thus very briefly brought before the reader some of more general considerations that would seem to justify the inference being drawn that, during the past half century JATS .of TEA RELATION to BLIGHTS and PESTS. Flushing Early. Liability to Mosquito. Change in Habitat. Liability to Red-spider. Con/, with para. 739. Blight-proof Con/, with para. 72. Conclusion. Report of Investigations in Aesam Indications of Deterioration. CONCLUSION Prevention Better than Cure. Pests as Indicative of Defects in Cultivation. Con/, with pnras. SO, 43, 45, Gl t 92, 1O6, 1V6 386, 197, 255, 315, 318, 3X0. Extent of Personal Explorations. Con/, with, paras. 2, 55, 92, 316. of cultivation, many very remarkable changes have taken place in the properties and disease-resisting powers of the Assam plant, I need hardly add that the problem, to my mind, that presents itself for con- sideration is more one of methods of prevention rather than of cure. In a further part of this report, I shall endeavour to set forth all I have been enabled to discover regarding each of the chief maladies of the crop, but the final conclusion arrived at, from the study of these pests and blights, is, I presume, of greater consequence than pure scientific details. That conclusion may be stated briefly, that reforms in the selection of seed, better systems of tillage, more rational pruning and less severity in plucking, would bring about improve- ments in the health and yielding properties of the plant, of a far greater and more lasting character than could be accomplished by the discovery of methods of curing one disease after another. To effect a cure, without the removal of the predisposing conditions, would, in all probability, be in each case to prepare the way for another and perhaps a more disastrous enemy. I do not, however, wish it to be supposed that there is no occasion to study the diseases, nor to attempt to work out the life histories of the parasites to which the plant has become liable. The surest indication of defects in soil or in cultiva- tion, will unquestionably be obtained by a study of the enemies of the plant. But even when methods of improvement have been fully established, it would still be necessary to eradicate parasites, so that the study of the pests and blights of the plant must be looked upon as an imperative obligation laid on every practical planter. With these remarks it may now be desirable that I should attempt to exhibit, one after the other, some of the more important features of tea-planting that I regard susceptible of improvement. I would crave the indulgence of the reader, however, for any mistaken con- ceptions I may have fallgn into, and by way of apology for my shortcomings would offer the reminder that my knowledge of the subject may, in perfect fairness, be characterised as acquired during a ride of two months' duration through the tea districts of the province of Assam. Personally I should have preferred to delay publication until I had had further opportunities of verifying or correcting my im- pressions ; but it has been thought that a statement of my views, how- ever immature, might nevertheless be useful as indicating the direction investigation might now take and probably as originating a more liberal exchange of ideas and experiences than we at present possess. Tea Pests and Blights. 33 Plant Life. CHAPTER III. PLANT LIFE. 55. While fully conscious that it would be both undesirable and un- satisfactory to attempt in a few pages a scientific account of even the leading features of Plant Life, it may serve a useful purpose, neverthe- less, if I endeavour to bring to mind some of the leading facts that should guide the tea-planter in his out-door operations. I shall, there- fore, only touch on those aspects of this very instructive study that have a direct bearing on Hoeing and Weeding, Draining, Pruning, Plucking and Manuring. It should accordingly be understood that the few brief paragraphs that comprise this chapter have been offered with one object, namely, to help to elucidate certain practical recommenda- tions which I feel called upon to lay before those interested in tea- planting. My remarks must not, therefore, be judged according to the standard of advanced research into the physiology of plants. IX. Nutritive and Reproductive Systems. 56. Parts of the Plant. It is customary to speak of the parts of a plant as consisting of two sets. Nutritive and Reproductive. The former are concerned with the life of the individual, the latter with the perpetuation of the species. The nutritive organs may be said to be the Roots, Stem, Branches and Leaves ; the reproductive, the Flowers and Fruits with their ultimate offspring the Seed. Although not absolutely correct, it may be said that the roots are the mouths of the plant, and that the leaves are both the lungs and the stomach. The food of plants may be expressed briefly as Air, Water and Mineral Substances. The atmosphere being but indirectly under the control of the agriculturist, his attention is mainly directed to the soil. Under the Chapters on Hoeing and on Draining, an effort will be made to indicate the manner in which the cultivator may take full advantage of the valuable properties of air. By drainage, moreover, not only can the soil temperature be raised, but even climatic condi- tions beneficially influenced. Air may be regarded as consisting of Oxygen and Nitrogen, two gases that are intimately mixed up but which remain chemically free NUTRITIVE TIVE. PLANT LIFE. Conf. with pnrn.fi. 117, 186. Nutritive and Reppoduetive Functions. Mouths of the Plant. Food of Plants. Value of Air. Composition of Air. 34 Report of Investigations in Assam Plant Life. NUTRITIVE REPRODUC- TIVE. Nitric Acid. Respiration, Con/, with para. 61. Chlorophyll. Con/, with para, GO. MaWals. Assimilation. 'Cow/, with paras. 58-64, 117,183-4, 245, 268, 297. from each other a wonderful fact and one of the greatest importance. During thunderstorms, however, actual union takes place between a certain amount of these two gases, and a compound results which by a further union with the elements of water becomes Nitric Acid. That acid is of the greatest value to the plants since it contributes toward the decompositions of the soil by which insoluble substances are rendered soluble. But the air also contains a very considerable amount of Carbonic Acid gas, and a lesser amount, of an equally valuable compound, Ammonia. 57. Respiration. Animals inhale the air in order that its free oxy- gen may be combined with the waste carbon of their bodies forming carbonic acid, and this is exhaled. Plants breathe by precisely the same principle, but added to their respiration they have a process of digestion. Under the influence of the light rays of the sun, acting on the green colouring matter of the leaves, the carbonic acid of their exhalation, as also the carbonic acid of the atmosphere, is decom- posed, the carbon retained as a food material, and pure oxygen ex- haled. During night, however, this absorption of carbon does not take place, so that the respiration of plants is then demonstrable as identical with that of animals. 58. Food Materials. The food of animals has to undergo a regular series of chemical changes collectively designated Digestion, before it can be absorbed or utilized. Moreover, the food materials of animals are very different from those of plants, since animals are unable to live upon earthy or inorganic substances. The animal is in iact entirely dependent on the plant for the preparation of its food. Plant food may be said to be oxygen, hydrogen, nitrogen and carbon, (all derived from air and water) also certain earthy materials obtained from the soil. The plant possesses no stomach strictly so speaking, but nevertheless its food materials have to undergo chemical changes, by a process designated Assimilation, which closely corre- sponds to digestion, before they can be built up in the tissues of the plant. Although the proportion of mineral matter eaten by plants is comparatively small, the higher plants at least cannot live without certain mineral substances. Each plant may be said to demand certain inorganic substances, otherwise it will not grow. The agriculturist, in his efforts to improve the soil, has, therefore, to direct attention chiefly to these indispensable inorganic food substances. During the process Tea Pests and Blights. 35 Plant Life. of assimilation the food materials are built up into various organic compounds, and these again are utilized in the formation of plant tissues. Briefly, the organic compounds of plants may be said to be: ist. Starches or compounds built up of oxygen, hydrogen and carbon, in varying proportions. Of this nature may be mentioned starch proper ; cellulose or the constituent of wood and fibre ; gum ; and, lastly, sugar. 2nd. Gluten or the Protein compounds. These contain nitro- gen in addition to the oxygen, hydrogen and carbon of the starches, as also smaller proportions of sulphur, phosphorus, etc. Of this nature may be mentioned gluten proper ; albumen ; casein, etc., etc. All living and growing vegetable tissues contain a certain pro- portion of protein matter and a liberal supply of nitrogen is, there- fore, indispensable to the life of plants. Let it be added in passing that nitrogen may be regarded as derived mainly, if not entirely, by the roots. 3rd. Oils or Fats. These all agree in containing less oxygen than would be necessary to convert their hydrogen into water. 4th. Water, an article of food the elements of which are occa- sionally separated and utilized in the formation of cer- tain compounds. X. Circulation of Sap. 59. Groivth* On placing a seed under the conditions of germina- tion the first change that takes place may be said to be that a portion of its protein undergoes a sort of putrefaction by which it is converted into a substance very generally designated Diastase. That substance is no sooner produced than it acts upon the store of starch (also con- tained within the seed) and converts it into a form of sugar, which being soluble thus increases the specific gravity of the cell contents. Osmose is in this way brought into action, that is to say, water is absorbed. It passes through the component cell-walls of the seed, obedient to a law of nature that a balance must be at once struck, should the specific gravities of two adjacent fluids be disturbed. 3 A NUTRITIVE REPRODUC- TIVE. Chemical Compounds of Plant Tissue. CIRCULA- TION. Conf. with paras. B9-64, 118, 231. Growth. Diastase. Law of Osmose* Report of Investigations in Assam Plant Life. CIRCULATION Action of Chlorophyll. Growth. Ascending or Crude Sap. Water. 60. The latent embryo being thus supplied with soluble food materials commences to grow. No sooner has its young stem and leaves ascended above ground than their cells become charged with a green colouring matter ( Chlorophyll) the services of which are now eminently required. With the exception of the moisture and the small amount of soluble substances absorbed, growth hitherto must be viewed as simply the result of the embryo having been able to use the materials which had been stored up for it within the seed. It may in fact be defined as growth the result of re-arrangement. But no sooner have the roots penetrated the soil and the leaves unfolded in the atmosphere than three distinct phenomena make their appearance : jst. The sun by evaporation withdraws moisture from the leaves and thus the specific gravity of their cell- contents becomes increased owing to concentration. 2nd The leaves commence to breathe and purify thereby what may even already be impure. 3rd. The leaves decompose the carbonic acid of the atmosphere inhaled by them, retain the carbon and set free the oxygen. 61. Ascent of Sap. For convenience we may view these con- ditions as originating the circulation of the sap and commencing the process of assimilation. It has been stated that by osmose the specific gravity of the cell-contents of the delicate roots that had emerged from the seed, was lowered. But by transpiration from the cells of the leaves, the specific gravity of their cell -contents is now raised. In consequence the cells above draw on the cells below for an extra supply of moisture. This suction from above and osmotic pressure from below may thus be viewed as sufficient to originate a circulation of fluid through the plant tissue. The ascending current is called the Crude Sap, because, while it contains many of the necessary food materials, they exist in a condition that cannot be utilized. The crude sap has to undergo a series of changes which, as already stated, are collectively designated the assimilation or digestion of plants. 62. But let us see what the crude sap contains, before we proceed to discuss the changes of assimilation. Water of course constitutes by far its largest proportion and is in addition the medium, through Tea Pests and Blights, Plant Life. which other substances have been absorbed for the food materials of plants must be soluble. Held in solution, then, the crude sap contains nitrogen and nitrates. These nitrates have been derived from various sources, such as the ammonia of decomposing organic matter and of the air, nitrates formed by the nitric acid of the air, and last but perhaps the most important of all from the nitrating organisms of the soil which originate chiefly from the roots of leguminous plants. Lastly, the crude sap contains the mineral substances derived from the soil. 63. Avoiding all controversial points, it may not incorrectly then be regarded that the current of water, laden with these food materials, ascends through the young layer of wood, immediately underneath the bark, being propelled by the following amongst other forces : osmotic pressure below, suction due to transpiration above, the chemi- cal affinity that the cell-walls possess for water, capillary attraction between layers of cells and tissues, and, lastly, the decomposition of water and the utilization of its component elements during assimila^ tion. 64. Assimilation and Descent of Sap. By whatever means it may be, this is certain, that a steady current of sap ascends amongst the young wood cells and, [on reaching the leaves, is acted on in the three ways already mentioned. It is concentrated by perspira- tion, it is purified by respiration, and it is carbonised by decomposi- tion of the carbonic acid gas of the atmosphere. This carbon enter- ing into combination directly with the elements of water, forms one or other of the soluble starches. By union with water, with carbon and with a nitrate, protein matter is produced. In this way, then, many nutritious food-stuffs are formed. The sap is now digested or as it is called assimilated, and it slowly makes its way downwards by diffusing itself through the entire substance of the plant. From the elaborated Descending Sap the various tissues and structures are able to pick out the compounds which they require and these built up within the cells, cause them to grow, and finally, when mature to multiply, so that with vigorous circulation of sap rapid growth takes place. XI. -Conditions of Maturity. 65. Plant Tissue. The cell maybe said to be the ultimate struc- ture. It is a small sac, the containing wall of which is composed of CIRCULATION Of SAP. Origin of Nitrates. Con/, with para. 296- Nitrating Organisms. Cow/, with para*. 1G5 > 285, 297- 313. Position of Current. Motives of Circulation. Assimilation. Agents of. Descending Elaborated Sap. Position of. Plant Structures i 220644 Report of Investigations in Assam Plant Life. CONDITIONS of MATURITY. Formation of Wood. Conf. with piirns. 176, 183, 186, 190, 199, 2O5, 225. Production of Flowers. Conf. u-ith para. 29. Continuous Growth : Flushing. Improve- ment of Soil. Conf. with paras. 58, 9S-4, 108, 114-16, 128, 282-313. cellulose. One of the most striking peculiarities of the cell-wall has already been mentioned, but may be here more pointedly recapitu- lated. Although devoid of pores of any kind, fluids pass freely through in obedience to the law of osmose. The cell-contents are of a liquid nature with sometimes solid materials formed within. Many microscopic plants consist simply of one cell. Others are built up of cells all of one shape and size, like the bricks of a wall only that they are living bricks that increase in number by cell division. In still a third class of plants the cells are of different shapes, many compacted together and even fused, end on end, into tubes that ultimately form fibrous tissue and wood. These changes in the shape and also in the special adaptations of the cell, are brought into existence in obedience to the demand for the accomplishment of fixed and definite functions, attributed to the various organs of plant structure. The walls of the cells are thickened when the object is to form wood ; the cell-walls in that case gradually become impervious to fluids and thus cease to participate in the circulation of sap. Wood is, therefore, developed to give strength and support to the young growing shoots and to bear the flowers and fruits. 66. Reproduction.-Eut the formation of wood, beyond certain limits, when the object aimed at by the cultivator is a free circulation of sap and rapid production of shoots, may be regarded as an un- favourable and undesirable symptom. It is an unmistakable sign of the advance of age and will assuredly be followed by the produc- tion of flowers and fruits. When, therefore, a plant has attained maturity, reproduction becomes the governing principle of its future life. Should it be prematurely aged, by adverse circumstances, it may similarly be seen to put forth an effort to make up for the fast approach of its own death by the production of the germs for a new generation. XII. Practical Lessons to be Learned, 67. Continuous Growth Flushing. To the tea-planter, there- fore, the production of wood or of flowers should be looked upon as untoward circumstances. In both cases pruning becomes a necessity. But pruning must go hand and glove with soil improvement, for if a check be given to the natural desires of the plant, viz., to provide for a new generation, without supplying it with the materials necessary for continued growth, the shock may prove fatal. But it should Tea Pests and Blights. Plant Life. never be forgotten that the cultivation of the tea plant, figuratively speaking, might be characterised as a forced procrastination in the ful- filment of a universal law of nature. And the simile which it is here desired to draw is but partially true. The lower portion of the stem may represent a seared old age, forced through pruning and cultiva- tion, to continually renew its youth. But the presence of old wood in the stem, by retarding circulation and constantly forcing on the younger upper shoots the necessity to flower and fruit, must be in- jurious to the planter's aims and objects. 68. Under the Chapters on Pruning and Drainage, an effort will be made to exemplify the chief peculiarities of the roots. It may here, however, be explained that absorption takes place chiefly in the minute hairs that surround the ultimate fibrils. Hairs are in many cases greatly elongated simple cells. They suck in the moisture of the soil, charged with food materials. This is transmitted from the young roots along the older roots to the stem and onward to the leaves. The activity of absorption depends, however, almost entirely on the demands of growth and is regulated by the leaves. Transpi- ration and assimilation are not physical phenomena. The mouths of the leaf are minute openings in the epidermis (stomata), mostly situate on the under-surface. These open, to allow of free transpiration, or close when a rest is desired, and thus directly control the roots. The strength of the ascending current of sap is accordingly depen- dent on the extent and activity of the young growing shoots and the number of fresh hungry leaves. Old mature leaves practically take no part in this action. They are thick, hard and dark-coloured, because the cells of which they are composed have become fully charged with food materials. 69. In the Chapter devoted to Plucking, an explanation will be offered as to the meaning of flushing. But in passing it may be said that the knife having secured for the planter, the effort, on the part of the plant, to produce new shoots (instead of maturing those already in existence, with the view to the production of seed), a vigour has been given to the roots which must either result in " bleeding " from the cut surfaces or in the production of more and still more shoots to take the place of those plucked off. 70. From what has been said it, therefore, may now be fully under- stood that pruning for the production of leaf is, and must be, a very PRACTICAL LESSONS. Old Wood. Root*. Demands of Growth. Breathing Mouths. Flushing-. Con/, with paras. 2O6, 220. Flowering and Fruiting. Con/, with para. 29. Bleeding. 40 Report of Investigations in Assam Plant Life. PRACTICAL LESSONS. Uprooting Replanting. Con/, with paras. 77, 79 28O-1. Preservation of Health. Production and Area. hurtful and exhausting proceeding. It should, accordingly, be pursued with either of two objects in view : (a) The death of the plant being accepted as a necessity, after a fixed number of years, the system of pruning should be that best calculated to secure the utmost return during the life of the plant. (V) The object being to preserve the plant indefinitely, the system of pruning pursued should be that calculated to give the highest annual return, commensurate with the health of the plant. In connection with these two considerations the reader is referred to the remarks under Deterioration (pp. 755-760), more especially the concluding observations on the recent increased ratio of produc- tion to the expansion of the area of cultivation. Tea Pests and Blights. Seed Gardens and the Improvement of Seed. CHAPTER IV. SEED GARDENS AND THE IMPROVEMENT OF SEED. XIII. Indigenous Seed. 71. Localities. It may in all fairness be said that at present very nearly all that is stipulated for, in purchasing seed from a particular garden, is that a certain percentage shall germinate. The recom- mendation that the seed has been produced in an isolated spot, within a jungle or forest, where it is presumed to have been indigenous, may be said to vastly increase its value. The chief advantages claimed for such seed are, purity oijat and strength, due to the seed being the produce of semi-wild plants. I made a point of personally visiting as many of the seed-gardens as I could, and may say that in none of those seen did the conditions exist that would satisfy me as a botanist, that the plants were, strictly speaking, indigenous. There was very little in fact to remove the suspicion that they might originally have been planted. One naturally had to face the very pertinent question, How comes it that in the plains of Assam, the so-called indigenous tea, covers only small isolated patches of 5, 20, or at most 100 acres, while many miles of precisely similar jungle and forest extend around ? I think I am correct, however, in saying that the seed-gardens of Assam very nearly correspond to the localities where the plant was found by DPS. Wallich, Griffith and McClelland (the Commissioners appointed by Government to enquire into the existence of tea in Assam) in 1835. It seems probable that the localities of the so-called wild tea within the valley, have not been materially increased in number since DP. Griffith spoke of them as "patches of a very limited character." He mentions Kufu, Ningrew, Namsang, Tingri, Gabru, etc., etc. It is necessary, in fact, to leave the valley and to penetrate into the Naga Hills and Manipur before the tea plant can be said to form a feature of the prevailing vegetation over fairly extensive tracts of country. Then again the swampy jungles or damp dense forest tracts, in which most of these isolated plots of seed-tea occur, are about as dissimilar as it is possible to imagine, from the conditions that NDI *ous Conf. ^Hth paras. 39- SO, 49. Isolated 1-atehes. Report of Investigations in Assam Seed Gardens and the Improvement of Seed. IMPROVE- MENT Naga Hills and Manipur Teas. Possible early Cultivation. Hybrid Bushes in Seed-Gardens. Assam Indigenous- Variable Term. Recognition of Forms. Con/, with pat-ax* 27 and 28. PeAlt Selection. Con/, with para. 84. Blight Proof Cow/, with paras, 53, #87-88. prevail, in what may be viewed as the forests of truly wild tea in the Naga Hills and Manipur. I do not think that it has been satisfactorily made out that there never was, on the fringe of high land that skirts the mountainous walls of Assam, a condition of native tea cultivation, such as exists at present in the Shan States, long anterior to the existence of the European industry. If this idea be allowed to gain cre- dence, the observation repeatedly recorded by me, while examining seed-gardens, that in few indeed of these gardens could the /a/ of tea be pronounced uniform, would at once be accounted for. It does not by any means follow that the first China tea plant that reached the valley of Assam came to it, as the result of the enlight- ened action of Lord William Bentinck in his efforts to organize the modern tea industry. I have not infrequently seen unmistakable hybrid teas in some of these so-called indigenous seed-gardens, but even were these removed it could hardly be said that the remainder manifested throughout a constant type. " Assam indigenous " is, in my opinion, a very comprehensive term indeed, so that we should speak of badyW Assam indigenous just as we freely admit the term bad hybrid. 72. Recognition of Different Forms. It may, in fact, be doubted, were the owners or managers of seed-gardens invited to pick ou the plots of land in a garden that had been planted with a certain percentage of their seed, whether they could make more than an occasional successful guess in that direction. In other words, I do not believe that any one of the famed seed-gardens could be said to produce more than seed of a certain locality, although it may be admitted that a distinct percentage of that seed has been proved to satisfaction to possess fairly constant properties. My contention is, however, that with a little more attention to the establishment, through selection and vigorous extermination of all departures from a required standard, it would be possible to very greatly improve the quality of the seed even in the existing seed-gardens. There should be no more any difficulty in the future to produce and maintain in each seed-garden a recognizable jat of tea, with ascertained properties and suitability to certain climates and soils, if not freedom from certain diseases, than there has been found to produce and maintain the famed pedigree wheats, or the prized races of potatoes, peas, cab- bages, roses, fruits, etc. Tea Pests and Blights. Seed Gardens and the Improvement of Seed. The same attention has not been given to the subject of tea seed as has been expended on that of most other agricultural crops, and hence the apathy that prevails on the supply of seed. The manager of a garden on showing a plot of land under a certain famed stock, will often freely enough admit that it is by no means of one uniform jat. Inferior hybrids may be recognized in the field, but he will blame his own subordinates for not having rejected these in the nursery stage, instead of viewing them as possible indications of the condition of the seed-garden or of adulteration in supply. He may even uphold the opinion that seed from such and such a locality, whatever the jat may be botanically, has certain properties. In other words, he may maintain that the environment of the seed-garden is of equal, if not of greater, importance than the particular jat of tea grown in that garden. 73. Selection. It is needless to attempt to give here an essay on the principles usually followed in selecting and perfecting culti- vated races of plants. Suffice it to say briefly that were I called upon to undertake such a task I should most certainly work back from the tea garden itself instead of forward from the so-called " jungle seed- garden." The tall unpruned plants in the seed-garden (or in fact all tea bushes left to grow at will) have lost most of the external peculiarities of form and colour of leaf, and habit of branching, by which they are recognizable the one from the other. It is accordingly a matter of considerable difficulty to identify the prized forms of the tea garden in the seed-producing state, since all become in the seed- garden very much alike. It follows that the various jafs of tea found in the leaf -garden should be carefully studied and their various merits ascertained by comparative tests before any start is made with the seed-garden. 74. If by these means it were observed that one bush possessed certain properties of merit, such as, that it flushed exceptionally freely or early ; that it enjoyed immunity or perhaps only suffered less severely from particular blights ; or that it succeeded better on a peculiar soil (for which it was desired to have a special stock), than any of the other forms in the garden, I should single out that individual plant for experiment. So again if I found a bush that flowered and fruited freely in the stunted form of the tea garden, I should look upon that as a possible advantageous property that might be perpetuated with the view IMPROVE- MEST SEED. Adulteration. Selection. Working from the Tea Garden. Individual Bushes Experi- mented with. 44 Report of Investigations in Assam Seed Gardens and the Improvement of Seed. IMPROVE- MENT of SEED. Propagation by Cuttings. Stock for new Seed- Garden. Objections to Improvement of producing from the Assam indigenous a plant that would in some respects resemble the China stock. I should have each bush that manifested special properties deemed worthy of investigation isolated, by an enclosure, so that it should not be plucked or otherwise interfered with. It could then be studied carefully with the view to ascertain whether the peculiarity it possessed was more or less fixed. It might then become necessary to cover it completely with a fine wire gauge frame so as to prevent cross fertilization on its reaching the flowering stage. After a sufficient supply of well-formed seed had been obtained from it, I should remove the enclosure and treat it like the other bushes, but have that individual plant numbered and recorded as the standard upon which improvement was to be effected and with which compa- risons were in the future to be made of the results obtained. Another method would be to produce by cuttings a large number of plants from some particular bush in order to see if its special pro- perty was preserved. Having previously selected and prepared a bit of good tea land in the jungles, say, a mile away from the garden, I should now sow the seed there or plant out the rooted cuttings. Doubtless many of the seedlings, after a year or two, would give indi- cations that the seed had been hybridized in spite of every precaution. Every seedling or cutting that manifested the slightest departure from the arbitrarily selected standard I should have instantly removed, and after a time only some half a dozen of the best and purest retained. These I should allow to run to seed, but when the flowers began to form would pluck off a large number, and in order to secure fertiliza- tion within the specially selected individuals and to obviate the risk of external influence, would mechanically fertilize the flowers from which this second stage of seed was desired. After obtaining the required quantity I very possibly might next exterminate the plants in the seed- garden and trust to the new and less hybridized supply. Repeating the process of sowing I should again eliminate all the seedlings, say, when they were two or three years old, that manifested the slightest tendency to depart from the structural peculiarities that it was desired to develop. This would take many years no doubt ; but, by a process of careful selection, a definite type of plant could easily be developed and fixed. A supply of seed might then be obtained to plant out a fairly large seed-garden. 75. Want of Continuity. As against all this I am reminded of Tea Pests and Blights. 45 Seed Gardens and the Improvement of Seed. the want of continuity or continuance of interest in everything Indian The scheme described would take years, and before it had advanced very far, those originally entrusted with the experiment would very possibly have disappeared from the scene of this very interesting scientific study. But if that be regarded as unanswerable, then the outcry against the spread of the diseases of the tea plant is irrational. If those who have the control of so many millions of pounds sterling cannot or will not follow the dictates of universal experience in all other branches of agricultural enterprise, there is nothing further to be said. But I cannot believe that the large, wealthy and influential companies that are concerned in the world's supply of tea, would admit that there existed any element of uncertainty in the matter. The executive may be changed, but any policy once inculcated need in no way suffer by such accidents. The suggestion might, moreover, be here made, for the consideration of the Tea Association, whether it would not be desirable to bring to India a professional'seed-grower and to entrust to him the experiment of improving the quality of the tea seed, in a set of seed-gardens to be owned and supervised by the Association. But I am asked, Could the owners of the present seed-gardens be expected to support such a scheme ? Perhaps not ; but if they are so short-sighted as to think there is no room for improvement, I should at once disregard their opposition. In all such questions the interests of the majority, not the minority, have to be considered. But let me add, I think it my duty to express my views on the necessity for reform irrespective of financial or even practical considerations. It is for those con- cerned with such matters to discover how far and in what way effect can be given to these recommendations, assuming that they commend themselves as desirable. 76. Advantages of Uniformity of Stock. It is perhaps hardly necessary to reiterate the fact that gardens of mixed jats are far less productive than those in which greater care has been mani- fested in the selection of seed. It is also well known that gardens of fairly uniform and good jat are very nearly exempt from the rav- ages of mosquito, red-spider, etc. I have been taken over many such gardens and had convincing proof in others that it is in the inferior portions, with poor jat teas, where these and other pests first make their appearance, and from whence they spread to the better parts of Professional Seed-grower. IMPROVE- MENT of SEED. Uncertainty. Advantages Uniformity. Con/, with paras. 79, 89, 261. Report of Investigations in Assam Seed Gardens and the Improvement of Seed. IMPROVE- of SEED. I Evils of | Mixed Jats. Flushing Season. Blending. Recognizable Forms. Laurel- leavedlea. Peculiar Disease. Con/, with para. 831. the garden. To plant out a garden with some half a dozen jats of tea, one bush China, another Assam, and a third an inferior hybrid, or shall I put it two-thirds Assam and one-third inferior jats (dispersed through the better /aft), is to provide the conditions neces- sary for blights to attack the entire garden simultaneously. It was a mistaken notion that to plant Assam and China bushes together secured a good blend of the properties of the two stocks. It has long since been proved to satisfaction that there are mechanical difficulties in collecting and manufacturing leaves of mixed size, age and thickness. Moreover, differences of jat involve a further difficulty in the season of flushing and time necessary to mature each successive flush. If plucked when the one jat is ready, the others may be too old or too young, and a loss that may be appalling is thereby sustained. If it be thought desirable to have early flushing as well as late flushing plants, let these be in separate plots where they can be plucked at their respective seasons. Blending cannot be successfully accom- plished at the garden and should never be attempted since under the climatic conditions that prevail, during the manufacturing season, the sooner each day's produce is packed the better. 77. Certain Forms of Tea found in most Gardens. Any person who may be disposed to doubt these very sweeping statements, regarding the wide diversity of quality and yield of the different bushes that compose the vast majority of the gardens in Assam, need only walk into the nearest plot of tea and compare bush by bush. He will find the greatest possible differences in the shape, colour, texture, degree of prominence of the veins and of the marginal serra- tion of the leaves. If next he turns attention to the flushing power of two bushes of different jats, but of as near as possible equal size, he will find that one has only, say, 20 flushing shoots, while the other may have 100. Here, for example, is a bush with fine large, broad, thick and shining dark-coloured leaves, with coarse serration and with deep depressions between the widely arching veins. At a dis- tance it looks not unlike a Cachar/a/bush, but is larger and coarser built and spreads into stouter lateral branches than is customary with the Cachar. It was obtained, however, from the same seed- garden as the others and treated absolutely in the same manner as this other plant with smaller paler leaves and minute serration. The former may be seen to be liable to a peculiar blight. This may be Tea Pests and Blights. 47 Seed Gardens and the Improvement of Seed. described. A constriction occurs at the base of the leaf, the sides are compressed upwards, the leaf turns over to one side under the wind, the now upturned under-surface becomes at first purple, then brown and dies ; it is then attacked by a fungus. I have never seen that peculiar disease except on the Assam indigenous plant which I trust my description may bring to the mind's eye of the practical man. It may be asked, Is that large clumsy plant anything like as produc- tive as the smaller leaved, more erect bush growing alongside of it ? The two forms of tea here indicated are to be found in nearly every garden in Assam. The planter will now please turn round and look at this other bush, for behind him is a third form, a stunted plant with broad leaves that are deeply cut on the margin, until they almost look like those of the holly. These holly-like leaves will be seen to be abruptly ter- minated, instead of being gradually tapered. The newly formed wood has become prematurely brown and the plant is copiously branched and densely covered with ever-green leaves, but it flushes very indifferently. That is to say, the buds do not elongate quickly? the leaves rapidly become too thick and hard to be used as tea ; the buds in fact sometimes look like small green roses, and the plant for all the good that it does might just as well be dug up. Neither the laurel-leaved large bush nor the holly-leaved plant here indicated are profitable, compared with many other forms that might easily enough be substituted. Their dense dark green foliage give a vigorous look to the garden however, and thereby they escape the condemnation that they richly deserve. No treatment will ever succeed to bring bushes that are by nature non-productive into a state of efficiency. But I am told it will never pay to uproot even useless plants. That may be so (though I very much doubt it), but why plant useless bushes? A very short inspection of any tea garden will suffice to show most persons that there are different qualities of tea bushes both as to flavour of tea afforded and yield of leaf. If that be so, why should advantage not be taken of so ordinary an observation by developing the seed supply from selected stock. 78. Hybrids- The usual expression " hybrid " has been em- ployed in some of the remarks above, though of course the tea " crosses " are not, botanically speaking, " hybrids " unless the China plant be regarded as a distinct species from the Assam, which it Of SEED. Holly-leaved Tea. Var ying Quality. Uprooting Tea. Cow/, with paras. 35, 70, 142, 164. 225, 276, 280-1. Hybrids. 5 3 Report of Investigations in Assam Seed Gardens and the Improvement of Seed. IMPROVE- MENT of SEED. Extermina- tio n of China Jats. Peculiarities of Hybrids. Uniformity Vastly Improves Outturn. Inferior Hybrid. Coarse Plant closed up Leaves. Green-fly. Con/, with paws. 3O8- 10. certainly is not. The term is, however, convenient and need not be objected to. While the popular cry of the present day is to exterminate all China tea and all hybrids and to substitute indigenous jats, I venture to think there may be a danger in carrying this idea too far. There are undoubtedly good as well as bad hybrids and for some soils and certain climatic conditions a good hydrid may be better than the purest and best Assam indigenous. The very worst argument against the hybrid teas is their greater liability to mosquito ; their advantages are that they flush earlier and are less affected by deficient rainfall than the poorer jats* As already pointed out, they are dangerous when in- termixed with Assam indigenous, but under proper control might, in my opinion, be grown on special plots of land for which they have undoubted advantages. 79. The object I have at present in view, however, is to indicate the mixed character of the plants to be found in most gardens, in the hope of being able to convey the idea that a vast improvement in yield would result, were the gardens of the future planted with one form of tea only and that the one that had been ascertained of most value. " With old gardens where uprooting and replanting are considered financially impossible I would say, see that every vacancy is filled up by the right jat, and it is possible much sooner than might be supposed at first sight a complete renovation may be effected. But to return to the subject of the races of the plant it may be said there is an infinitely more ex- tensive series of hybrid, than of pure forms. Here, for example, is a large thick-leaved hybrid, with prominent veins, with the leaves excep- tionally narrow for their length, pointed at both extremities, and with the sides of the leaf closed upwards so as to show the lighter under- surfaces. The whole attitude of the plant conveys the idea of being parched or of giving indications of suffering from heat and want of rain. Many planters point to these peculiarities as indicative of the approach of green-fly. I have seen the condition here mentioned scores of times without a trace of green-fly and that too from March to July. But I have never seen the peculiarities mentioned occur in any form of plant except the narrow, pointed, dark-green-leaved hybrid here described. Like many other forms of the tea plant this has very frequently a disease of its own which may indeed be the This latter fact I suspect may be due to shallow soil saturation. See chapter on Drainage. Tea Pests and Blights. Seed Gardens and the Improvement of Seed. cause of the convolute closing up of the leaves. Over the surfaces of the upturned portions will frequently be seen a multitude of brown or black spots that give the plant a very unsightly appearance. These spots are due to the growth of pustules imbedded within the tissue that contain a wart-forming mite which may possibly be peculiar to this form of plant. Are hybrids of that character profitable ? Count the number of flushing buds and you will see that whatever be the cause of the parched condition, the plant is " banjhi" (=barren) that is, its buds have been arrested in their growth and are unproductive. The parti- cular form of plant here described is in fact infinitely more liable to become banjhi than is any other jat in the garden. 80. But there are other hybrids which in point of shape and size of leaf can only be definitely classified by counting the veins. They are sometimes called good hybrids, at other times bzdjats of Assam. From the indigenous teas they may be recognized at a distance by their thicker texture, more parallel veination and darker colour of foliage and also by the important fact that they come into bearing at a much earlier date. But I forbear to mention further the long list of hybrids that might be described in this place hybrids that differ from each other in shape of bush and size and texture of leaf until they gradually merge from the .pure Assam into the pure China. An infinite series might be picked out in any one garden, many of the forms of which, if carefully studied, would each be found to have properties of its own. 81. Process of Hybridization. But before leaving the subject of these hybrids it may be as well to say that I did not come across a planter who had actually mechanically hybridized different forms and ascertained for himself the advantages or disadvantages of this method of dealing with the jats of tea. What is more surprising, I have a letter before me now from one planter who denies that the forms commonly called hybrids have been produced by crossing the Assam indigenous and the China. There can, in my opinion, be no room for doubt that they are crosses between the two races mentioned, but it is surprising that the production of these crosses should have been left to accident. It seems possible that the female element in the inferior hybrids may have been the China stock. But this could only 4 IMPROVE- MENT of SEED. Wart-form- ing Mite. Banjhi! Bushes. Con/, ivltlk para*. 51t, 2O6, 23O. Veins of the Leaf. Conf. with para. 27. Hybridism. Crosses not Hybrids. Experiment necessary. Report of Investigations in Assam Seed Gardens and the Improvement of Seed. IMPROVE- MENT of SEED. Mixed Stock. Comparative Values. Percentage of Quality in Seed. Garden. Seeds. be determined by actual experiment. I desire pointedly to draw attention to the uncertainty that exists regarding the origin of the hybrids, in order to convey the idea that in crossing one Assam jat with another: Assam with Cachar; Assam with Sylhet; Assam with Manipur ; Assam with Naga ; Assam with Burma ; or Assam with China, etc., etc., very different results may be obtained in each of these from two stock plants, i.e., in the one case obtaining the seed from (a) Assam, in the other from () China. So again the strengthening effects of crossing the resultant with (a) or with (3) has not apparently been systematically tested. A very extensive series of such experiments might be tried, and who can say that he .who follows these up may not produce ajai of tea infinitely superior to any stock at present in existence. Hybridism has hitherto been left to Nature ; it has in fact been regarded as an unavoidable evil instead of being recognized as one of the possible means of solving the question of blights or of effecting improvements in the yield and quality of tea. 82. Mixed Stock. The above remarks on the mixed nature of the stock in most gardens must be held as sufficient for the present pur- pose. Since it can be demonstrated that one plant is less productive than another, an importance is at once given to a more careful selec- tion of seed, that should commend itself to all persons interested in tea cultivation. How the many difficulties that beset the adoption of measures of reform are to be overcome must be left for practical men to determine. It seems likely, however, that were a stipulation made, in seed transactions, as to percentage of quality as well as of germination, the companies who do a business in supplying seed would soon find it to their interest to free their seed-gardens of all doubtful paints. So far as I understand the contracts simply stipulate for seed of a particular seed-garden (such as Bazaloni, Tingri, Nam- sang, etc., etc.), but make no provision for uniformity oijat. It is apparently accepted that seed from a certain seed garden is of uni- form quality. XIV. Seed-Gardens. 83. Seed-Gardens. I cannot close these remarks on the desir- ability of effecting improvements in seed without repeating the con- viction that there is involved in the craving for seed from the jungles, Tea Pests and Blights. Seed Gardens and the Improvement of Seed. an error that, in my opinion, very largely underlies present evil. The seed-gardens are practically jungles that are cultivated very occasionally and indeed are situate, as a rule, in localities of such a nature that they can be visited at certain seasons only. For example the manager of one of the special seed-gardens informed me he would lend me an elephant, to enable me to try to visit the seed-garden, but would not undertake to accompany me nor give me any guarantee that I might be able to reach the garden. This was in June when the garden in question was supposed to be cut off from all communication by inundation, and for many months to come would be so. The plants are thus to a large extent neglected. They are not infrequently badly blighted and may thus be admitted are widely different from the plant as met with in the true wild habitats of the species, dealt with under paragraphs n and 27. I have seen more fungal blights in one or two seed-gardens than anywhere else, and some of these may possibly be found to be hereditary. On one occasion my atten- tion was drawn to the fact that a fungal disease (Brown Blight) seen on the leaf often attacks the superficial structure of the fruit and could be even recognized on the contained seed. Nearly every tree in most seed-gardens bears, as a rule, a Loranthus that is sapping its life and lessening its power to produce healthy seed. These parasites are doubtless systematically removed, but in the intervals of the visits paid to the seed-gardens, the trees become again attacked. 84. In my opinion, therefore, it would be preferable to the present system, were every large company to open out a seed-garden of its own, in some suitable situation and within manageable distance of head-quarters. The first step in that direction should be the selection of the stock, and in this the very greatest care should be manifested. Advantage in every direction might be expected to follow an almost hypercritical study of the seedlings intended for the future seed-garden. 85. Cultivation Necessary. The plants should be regularly and carefully cultivated, in fact to a greater extent than in the leaf- garden. It is hardly necessary to repeat that it is an erroneous as- sumption that seed from the neglected jungle, ordinarily called a seed-garden, can be superior to that obtainable scientifically. What such seed may be supposed to gain in strength, by production in a state of nature, is infinitely more than counteracted by the evils of the system. To argue that the wild seed of any plant could be superior 4 A "SB?" of SEED. Cut off from all Communica- tion. Brown Blight. Conf. with para. 828. Loranthus. Conf. with para. 798. Selection of Stock. Conf. with tar as. 72-74, Cultivation. Cultivated ied Superior to Wild. Report of Investigations in Assam Seed Gardens and the Improvement of Seed. IMPROVE- MENT SEED. Faces of Stock. Seed-Garden Sites. Habitat of wild Tea. Cow/, with para. 11. Sa Tree. Con/, with paras. 11, 11O, 297, 302-3, 311, 573. Pruning for Seed. Size of Bushes. Collection of Seed. to cultivated is to affirm that agriculture has not and cannot effect improvements in any direction, however much these may be desired by men. That wheat, oats, sheep, goats, etc., etc., existed in nature from all time as they do now, and that were we able to discover the original source from which the prized races of plants and animals had been evolved, it would be preferable to breed from the wild rather than the specially developed stock. With ideas of this kind currently held it would almost seem that the conception of possible improvement of stock was an unheard of doctrine a mere theoreti- cal speculation. 86. Selection of Site for Seed-Garden. To cause a healthy- bush to produce seed, its treatment must be entirely different from that pursued when the object is a perennial flushing of leaf. The soil selected should approximate as near as possible to that already mentioned as characteristic of the tracts of country in which the plant is truly indigenous. Low-lying, swampy, black, heavy soils, with much decomposing organic matter, should be avoided. A soil of red-clay loam, rich in lime and magnesia, should be specially selected and common salt added as a manure, should the soil be deficient in chlorides. In its truly wild state the tea never occurs in dense forest but rather in association with open mixed scrubby vegetation, and hence the seed-garden might with advantage be interplanted with clumps of some of the smaller bamboos and with Sa trees (Albiz- zia stipulata). 87. The pruning that should be annually given to the bushes should be the removal periodically of all branches that had already borne a sufficient amount of fruit or that were giving indications of be- coming exhausted. The primary aim should be to produce a healthy well-formed bush, with as little superfluous wood as possible. It is a matter of some practical importance to prevent the bushes from run- ning into unmanageably large sizes, since in that state they incur the risk of being broken during the rough handling they are often subjected to, in the collection of seed. That object would very possibly be attained by the systematic removal of one or more branches every three or four years. In fact the lopping off or thin- ning out of a certain percentage of overgrown boughs would do less harm to seed-production, where quality of seed was aimed at, than Tea Pests and Blights. 53 Seed Gardens and the Improvement of Seed. a more extensive system of light pruning. The pruning that should be pursued may briefly be said to be similar to orchard cultivation generally. But root-pruning should be systematically followed and that too every now and again. Deep cultivation is also essential, and opportunity should then be taken to cut a certain percentage of the roots. The deep hoeing and root-pruning should, as a rule, be accomplished not later than January and should only be undertaken when the soil is comparatively speaking dry. Deep hoeing in damp clay soils is distinctly injurious though sub-soil drainage with pipes placed at a safe distance from the roots would vastly improve the majority of seed-gardens. 88. Seeding, In Assam gardens the tea plant very nearly flowers throughout the year, but in the seed-garden it matures its fruits in October and November. Mr. Culbard, of Soongal, Kangra, informs me that in the tea gardens of Kangra, it ripens fruit from the 1 5th October to 1 5th November. In Assam ripe fruit may be seen occasionally at any season and this eratic seeding is distinctly objec- tionable. I picked ripe fruits from a seed garden, visited by me in the latter end of June. By careful selection there should be little difficulty in producing a stock that would fruit more uniformly, if not also at a more favourable season than at present. The danger of hybridization from the China stock, in the neigh- bouring gardens, is rapidly being removed, owing to the greater popularity of the Assam jats and the disappearance of the China. But with a few miles of jungle between the seed-garden and the tea there never was any great risk of cross-fertilization. The chief danger lay in the fact of mixed qualities existing in the seed-garden itself. 89. Seed-Production Dispersed through Tea Gardens. The habit of allowing, over certain portions of a tea garden, a selected number of bush to grow up for seed-production is, in my opinion distinctly reprehensible, as compared with the opening out of special seed-gardens. Even were all plants in the gardens of one uniform jat, so that the risk of crossing might be regarded as entirely removed the seed-bearing plants, under these conditions, cannot obtain, without injury to the leaf-bearing stock, the necessary treatment. In all the gardens where I have seen this system pursued, the plants ar simply exaggerated leaf-bearing bushes and possess none of the IMPROVE- MENT of ED. Root- pruning. Seeding. Danger of Hybridiza- tion. Produced in the Ordi- nary Leaf Garden. Cannot be Con/, with Y, 76, 7t>, Mil 54 Report of Investigations in Assam Seed Gardens and the Improvement of Seed. IMPROVE- MENT of SEED. Exchange of Seed. Improvement in Yield. peculiarities that are essential to the production of a limited quantity of high class seed. Personally I should prefer the seed from the jungle gardens to that of leaf-bearing bushes that had been selected for seed-production. 90. Exchanges. But there is one point that must still be men- tioned on the subject of seed-production. It is the all but universal ex- perience in agriculture that seed had better not be raised in the local- ity where it is to be sown. An advantage is universally admitted as secured by an exchange of seed. But were all the larger companies to accept, as an obligation laid on them, the duty of opening out seed- gardens and scientifically studying the best methods of producing the most ap proved jats of tea, exchanges might easily and profitably be effected. Indeed the extent of property held by many of the larger companies is such that with two or three small seed-gardens in different corners of their estates they need have no fear in using their own seed. 91. Conclusion. It is known that certain blights show a de- cided preference for certain races of the tea plant. Where such blights prevail to a ruinous extent selection of stock might amount to a suc- cessful remedial measure. The subject of seed-production should, therefore, not only commend itself to every person interested in tea, because of the high prices demanded for good seed, but because of the radical reforms and economies that would soon be effected were all future gardens, extensions, and replantations, made with carefully se- lected and approved stock. An undoubted increase of yield, with a corresponding lessened cost would take place and blights become of very much lessened consequence. Tea Pests and Slights. 55 Hoeing and Weeding. CHAPTER V. HOEING AND WEEDING. XV. Change in Relation to Disease. 92. The foregoing remarks have set forth some of the reasons that are believed to justify the opinion that, by the systems of cultiva- tion pursued in Assam, the physiological and even the structural peculiarities of the tea plant have been, and are being, constantly dis- tributed. The not unnatural result must be the gradual production of a cultivated stock that is not only diversified, but which collectively is gradually departing from the structural characteristics and chemi- cal properties of the original wild plant. The changes that have already been effected may be said to be on precisely similar lines to those that in China ultimately produced the form known to the Indian planter as the " China bush." It has in consequence been contended that thereby the plant has been, and is being, brought into a condition of predisposition to disease. In a series of chapters below some of the chief pests and blights> that have already invaded the tea plant, will be dealt with ; but it would appear desirable that an attempt should be made to discuss here the problems of cultivation that have been assumed as connected with the appearance and distribution of disease. In approaching this part of my subject I am conscious that I very possibly may be regarded as ad- vancing theoretical opinions in opposition to the accumulated ex- perience of half a century of practical tea-planting. For my short- comings I crave indulgence, but I may say that the time allowed me precludes my touching on more than a few out of the many aspects of tea cultivation that seem to me to deserve more careful study than has hitherto been bestowed on them. XVI. Objects of Tillage. 93. Tillage of the soil may be said to be undertaken with the two-fold object, viz., to open it up, in order that water may penetrate freely, and to turn up or expose again and again fresh portions of it to the direct action of both heat and air, in order that disintegration may take place. By these means the soil is mechanically pulverised CHANGE in RELATION DISEASE. 'reduction of New Condi- tions. Cnf with paras. 26, 30, 45, 51, loe, ma, 18G, 197, SIS, 318, 32O. China Bush. Predisposi- tion to Disease. Conf. with paras. 3O, 32, 47, 226, 282. Objects of Tillage. Conf. with paras. 54 t iia, ma. Report of Investigations in Assam Hoeing and Weeding. OBJECTS TILLAGE. Chemeial and Physical Changes. Conf. with para. HO. Rain-water. Fertility. Nitrogen Giving Organisms. Extent of Tillage for the Tea Plant Conf. with paras. 54, 155, 283. Extent of Weeding Necessary. Surface Wash. Conf. with paras. 99, 116, 124, 127, 153, 167, 216, 271. and at the same time undergoes certain very necessary chemical and physical changes that are essential before it can become available as plant food. Rain-water may be said to be nature's chief manurial agent. It holds in solution a large quantity of air which, as we know, consists of oxygen, nitrogen, carbonic acid, nitric acid and ammonia. Rain-water, moreover, has been warmed both in passing through the air and by its contact with the warm surface soil. Heat and oxy- gen bring about important decompositions in the organic ingredients of the soil ; the acids enter into union with its insoluble matter and render much of it soluble ; while the nitrogen of the air feeds the organisms of the soil, that are indispensable to the life of the higher plants. It is thus self-evident that if the soil be not fully and freely permeated by rain-water, it cannot be productive. Further, the more frequently and completely that the surface soil is broken up and exposed to the sun, air and water, the greater will be the disinte- gration of its insoluble mineral ingredients and the higher its fertility, 94. These then are the reasons that justify the hoeing, ploughing and draining of the soil. In a letter dating back some 25 years, a planter who signed himself "Dash " remarked : " If any one could inform us, planters, how the stirring up of the soil acts on the growth of the plants, we might take an intelligent interest in the cultivation of the ground." The answer is of course that cultivation, by the greater diffusion of air and water, enhances the volume and brings into the condition capable of being absorbed, the plant food-materials of the soil. But the further questions, by the same writer, show that he was by no means ignorant of the necessity for cultivation, but rather wished to ellucidate the nature and extent of the opera- tions necessary for the tea plant He accordingly proceeds to ask " whether it is better to have a well-stirred up garden, with a slight coating of grass, without wash, as is the case when ihe garden is forked over, than to have a clean hoed garden, baked by an Indian sun, after the surface has been smoothed by the rain and, wash? And does deep cultivation, say 9 inches, for the sake of allowing the moisture to descend, compensate for disturbing the roots when the bushes are growing ? If the garden is lightly forked over in the rains, would it be necessary to turn up the under-soil in the cold weather ? " 95. These pertinent questions roused the most superficial contro- Tea Pests and Blights. 57 Hoeing and Weeding. versy in the technical literature of the day and practically remain un- answered. The greatest possible difference of opinion still prevails all over Assam, for example, as to the number and depth of the hoeings that are necessary. The hoe versus the fork is still a theme hotly contested by men of long experience. The utility versus danger of weeds, can hardly be regarded as a subject of debate at the present day. The opinion is aH but universal that the freer a garden is of weeds the better. And yet there would appear to me to be no doubt that weeds of a particular class, by growing on the soil for short periods, would not only aid, as " Dash " suggests, in checking ruinous surface wash, but help in establishing the balance of the soil, so seriously disturbed by the cultivation of extensive tracts of country with a perennial bushy crop. I am fully aware that weeds with long powerful roots and stems which rise up above the height of the tea, would both injure the roots and suffocate the leaves. There must be nothing that would either interfere with the activity of the roots or retard the vigorous growth of the shoots, but can it be proved that succulent herbaceous weeds that do not exceed a foot in height, by being left on the soil for a couple of months or so injure the tea ? Would it not be safer to assume that by their taking the carbon from the air and building that up with the nitrogen and inorganic materials of the soil, weeds of the kind indicated assist in the improvement of the soil ? When hoed into the surface, in a moist green state, is it not safe to affirm that they are at once decomposed and act as green manure by giving back to the tea, in a prepared condition, the substances temporarily abstracted from the soil. 96. There is, however, a limit to the extent that even hoeing is beneficial. Every time the soil is turned up and pulverised it is exposed to the action of the atmosphere. It is dried, made porous, and oxidised. If a soil be already too porous, hoeing beyond a certain limit may become positively hurtful. Porous soils have usually a very low percentage of organic matter, as already explained, namely, that being porous, their organic materials have been rapidly oxidised and used up. For these reasons then rules for the hoeing of all gardens on a common plan cannot and should not be laid down, no more than that pruning can be made on the height principle, regardless of individual requirements. OBJECTS TILLAGE. Value of Weeds. Con/ 1 , with pnrns. g9, 107-9, 143, 267, 291-313. Balance of the Soil. Ferns, etc. Conf. with paras. 23, 800. Value of Herbaceous Weeds. Conf. u-ith paras. 99, 109-11,294. Manuring. Over- Cultivation Sandy Soils and Deficiency of Organic Matter. Conf. u-ith pnras. 113, 137, 285, 291, 313. Report of Investigations in Assam Hoeing and Weeding. It may help to bring out more clearly the opinions that prevail on the subject of hoeing if I furnish a brief abstract from the literature of this subject. XVII. Opinions of Authors in Hoeing of Tea Estate. 97. Mr. H. A. Shipp (Prize Essay on Cultivation and Manufacture of Tea in Cachar : Journal, Agri-Horti. Soc., Ind., Vol. XIV. Pub- lished, /866) says : " Hoeing should be constantly (say once in every two months) performed to a depth of at least 18 inches, and, on each subsequent occasion, to transplanting (prior to which two hoe- ings have been directed) the earth should be turned over in large clods with the roots of the weeds exposed, as they will thus die more rapidly and return to the soil, by being left on it, all the nourishment they have extracted from it." He further adds, " It is advisable to loosen the soil occasionally round the roots of the tea plants so as to give a free admission of air and moisture, and for this purpose the hand-hoe is best adapted, as in the use of the regular hoe, great danger is incurred of cutting the lateral roots of the young tea-trees." 98. Mr. W. C. MulleP {A few Observations on the Treatment of the Tea Plant in Darjeeling: Journ. Agri.-Horti. Soc., Ind., Vol. XIV., 1866) remarks that "The invariable practice on most planta- tions is to keep them as clean as possible by frequent deep hoeing throughout the year. I have four objections to this system : i St. The very great loss of soil by wash during the rains. 2nd. The. injury done with the hoe to the roots of the seed- lings. 3rd. The collar of the plant invariably gets covered. 4th. The total deprivation of shade." " During the fourth year the seedlings will have become a tree. You ought, if practicable, to give your plantation a deep hoeing, that is to say 8 inches, in September, just before the close of the rains, on every other occasion, when necessary, hoe lightly. If you wish to obtain a good supply of leaf, never allow the jungle to get more than 6 inches high during the rains; to ensure this you will find it necessary to give a light hoeing once a month." 99. Mr. Mullen wrote of Darjeeling and his remarks may be regarded as more especially applicable to gardens situate on hilly slopes. I hope, however, in a further chapter, to show that even on Tea Pests and Blights. 59 Hoeing and Weeding. the flat expanses of tea land in Assam surface wash is a frequent and dangerous phenomenon. To Mr. Mullen's four arguments in favour of a moderate coating of weeds being beneficial a fifth might be added, namely, that they protect the soil from the excessive evaporation of the hot months of April, May and part of June. 100. In passing I may invite attention to the first writer who pointedly drew attention to the fact that ulu grass (Imperata arun- dinacea) was one of the weeds that were distinctly hurtful to tea, namely, the late Mr. J. W. Masters. In a letter dated 22nd Novem- ber 1859 (Selections from the Records, Government of Btngal, No. XXXVII., pp. 47-48) he gives many interesting particulars regarding this grass, and his remarks contrast somewhat strikingly with the position of that enemy of tea cultivation at the present day. Constant tillage may be said to have eradicated the grass, to a con- siderable extent, from actual tea land. 101. Colonel Money (Prize Essay on the Cultivation and Manufac- ture of Tea ; first Ed., 1870 ; fourth, 1883), tells us that tea " will only pay with high cultivation, for high cultivation consists in frequent digging, to keep the soil open and get rid of weeds." In his special chapter on The Cultivation of made Gardens he says, "To conclude shortly, for ' hoeing and weeding ' I recommend as follows : " Dig the whole garden thrice in the year, viz., spring, rains, and autumn. Bury all weeds as you dig, in trenches between the lines. In the intervals use the Dutch hoe as often as weeds appear. Cultivate the plants by digging round them once a month if possible." "Do all this and you will find your garden is kept clean and well cultivated, at far less cost than you incurred for cultivation when it was choked with weeds for months together, while your yield will be at the same time much increased." 102. Mr. J. F. W. Watson (Prize Essay, Journ., Agri.-Horti. Soc., India, Vol. III., Pt. II., 1872), gives a very long and somewhat tedious chapter on this subject, although in many directions it is highly in- structive, more especially in the passages that deal with the eradication of injurious deep-rooted grasses. He concludes as follows : " To sum up the whole of these remarks to a practical conclusion, I would say that all lands under tea cultivation should be well deep hoed in the cold season ; secondly, that wherever dhaub, ulu or other OPINIONS of AUTHORS. Ulu Grass. Vonf. tiiith paras. 1O8, 11O, 3H9. Three Main Hoeings Re- commended. Light Hoeings once a Month. One Deep Hoeing a Year. Report of Investigations in Assam Hoeing and Weeding. such grasses infest a garden, no effort should be spared to thoroughly eradicate them, if for no other reason than that they are directly injurious to the roots of the bushes ; thirdly, that from March to the ist of November, the land should be light hoed at periods which should not be of greater frequency than once every six weeks, which interval, however, should not be much prolongated." Mr. Watson, though originally an Assam planter, wrote mainly of the tea gardens of the North-Western Provinces. 103. Mr. T. G. Stoker (Notes on the Management of the Tea Plant in Cachar, 1874), says of gardens in full bearing, " The great desidera- tum is that the lands shall be kept free from weeds and other rank growth which tend to keep the ground in a continually cold un- healthy state." " To hand-weed and hoe alternately I consider a good plan and during the rains this should be done as frequently as can be afforded." " During June, July and August the garden should, if possible, be kept scrupulously clean, and the surface crust occasionally broken with the hoe, so that the plants may be in an active warm state and thus suffer less from excessive rain." 104. The chapter below on Drainage will, I trust, show that the line of reasoning pursued by Mr. Stoker as to the soil being cold when covered by weeds is a little obscure and not in accordance with the usual experience. If properly drained, land can never be said to be injured by rain short of actual inundation. But Mr. Stoker returns to the subject and is certainly correct when he says, "Deep hoeing during the rains is injurious." The true reason for this is not, how- ever, that given by Mr. Stoker, but will be found in an article that appeared in the Tea Cyclopaedia (reprinted from the English Cyclopaedia), namely, that clay soils if interfered with when saturated with water are very apt to cake (the process known as puddling) when they become impervious to both water and air. As the best tea lands are clayey loams, it may be accepted that the risk of caking is very great. Although not quite in the sequence of this brief abstract from writers, on tea cultivation, it may be said that Mr. Bamber's re- marks on the injury done by hoeing saturated clayey soils are both instructive and accurate. He writes of heavy clayey soils, "These soils should, if possible, never be hoed during heavy rain, or when completely saturated with moisture, as hoeing at such times is certain to make them more consolidated and compact than ever, rendering Tea Pests and Blights. 61 Hoeing and Weeding. future hoeings more laborious and expensive. If the hoeing is done when the surface soil has become a little dry, it will be found that the soil will not become as adhesive as before, and if this method is continually practised, it will rapidly become more open and friable." 105. Notes on Tea in Darjeeling is the title of a little book that may be here placed under contribution : " One deep hoeing and two or three light hoeings are all that are required by a hill garden. The garden ought to be hoed deeply in November, and as big clods as possible turned up and left unbroken, thus letting as much light and air into the soil as possible. No more hoeing should be done until May." "Many planters hoe deeply, during the cold weather and go over the land in March, breaking up all clods, the real reason in many cases, why this is done, is that the agents have ordered the managers to hoe the garden a fixed amount of times, and this is an easy way out of it." 1 06. By far the most valuable account of tillage of land, in adapta- tion to tea cultivation, is that by Mr. M. Kelway Bamber (Chemistry and Agriculture of Tea, 1893). "Cultivation of tea soils," he says, " at the present time is confined almost entirely to hand-weed- ing, forking, or hoeing, chiefly the latter, and the amount and kind of such cultivation is regulated more by the amount of labour available on the garden, than by the requirements of the different classes of soil. It is a well-known fact in agricultural practice, that heavy and light soils must have very different treatment, if successful results are to be obtained, and the same thing holds good in respect of tea soils, though, as a rule, it seems to be lost sight of. It must be remembered that it is as easy to over-cultivate some soils, as to under-cultivate others, resulting in both cases in detriment to the bushes." XVIII. Advantages and Disadvantages of Weeds. 107. It would be unnecessary for me to quote any further from Mr. Bamber's most admirable chapter on Cultivation. His book is in the hands of most planters, and this chapter deserves very careful consideration. I not only concur most heartily in the opinion ad- vanced in the last sentence, but were it desirable could mention several gardens, with light friable soils, where I am satisfied injury is being done by over-hoeing. Indeed I am strongly of opinion that in the majority of gardens the error tends to lie on the side of over, One Deep and Three Light Hoeings. Report of Investigations in Assam Hoeing and Weeding. rather than under, hoeing. In my opinion it is an unfortunate cir- cumstance that tea cultivation has come to mean surface hoeing. Far better results would be obtained (at less cost in the end) by a thorough system of drainage and half the number of hoeings. Moreover, as may have been gathered from the remarks already made, I am sceptical of the advantages to be derived from gardens being kept permanently in the condition of some of those I visited in Assam (for example, in the Tezpur District), where no trace of surface vegetation (weeds) could be found anywhere. I fail to see how succulent herbaceous plants, with roots not more than a few inches in depth, could be injurious to the tea. On the contrary, when it is recollected that, of the total area of a garden, perhaps from one- fourth to one-third exists in the condition of spacing between bushes and thus unprotected from the sun throughout the year, and for an indefinite number of years, the question naturally arises, Is this a healthy state of affairs ? Are there not certain months of the year in which a light coating of vegetation would be not only a protection against excessive evaporation, but against useless disintegration ? 1 08. Experiment to Prove Extent of Hoeing and Weed- ing Desirable.! should like to see the experiment tried, for say eight or ten years, of a plot of land 30 acres in extent, consisting of a fairly uniform soil throughout, similar drainage all over, and with exactly the same age and/a/ of bushes, being divided into two equal sections and experimentally tested as follows : one half to be deep hoed three times a year, light hoed once every month and carefully weeded so that not a trace of weed could be seen anywhere through- out the entire experimental term. The other, once deep hoed and light hoed not more than four times a year, weeds being kept down during July, August and September, when thought excessive, and at each hoeing carefully buried in the soil. I should of course wish the returns preserved to be as follows : (a) Total expense of cultivation of each plot separately. () Average price obtained for the tea of each plot separately. ( 285, 2!>4, Hoeing and Nothing but Hoeing. Advantage of So, Trees. Standard Pruning Possible. Grass. Mid-Season. plant, or which exist in a condition unsuitable for it, are accumulat- ing, until the time might be supposed as rapidly approaching, when such accumulations may become positively hurtful. No rotation of crops is possible with a perennial, such as tea, and the only way, as it seems to me, to meet this difficulty is to encourage the growth of especially selected weeds for a certain number of months a year. These would undoubtedly attack the very ingredients of the soil tea does not use, while on being hoed into the soil they would furnish a greatly needed additional supply of organic matter which the tea urgently requires. If, therefore, a certain proportion of the weeds en- couraged and even sown on tea land, belonged to the family of the clover (leguminous plants), these would greatly facilitate the much- needed supply of nitrogen to the soil. I shall return to this subject in connection with Drainage and the Manuring of tea lands and need only add, therefore, that I am in favour of some scheme being designed by which specially selected weeds are allowed to occupy the soil for a certain number of months a year. The doctrine that cultivation of tea means hoeing, and no- thing else but hoeing, I most distinctly demur to accept. Moreover, I feel more than convinced that the unhealthy state of the tea bushes in many gardens should, to some extent at least, be attributed to excessive hoeing. Diary Notes on Hoeing and Weeding. 1 10. The following passages on this subject may be given from my Diary: At a garden visited on 24th April, some half a dozen planters met together and a discussion ensued on many important practical questions. The possibility of over-cultivation came up. One gentleman said he knew cases where increased coolie labour and more hoeing had vastly improved the yield. He held that Sa trees had not been shown to increase the yield though he admitted that an estate, where they had been largely grown, was one of the finest in the district, and its last year's profit a very handsome one. He thought that, if every bush could be pruned on its own merits (p. 102), it might be of advantage ; but that by pruning on a fixed system bad plants were killed off and the garden brought to a uniform state in which a definite system for all practical purposes became possible. If not given at least three deep hoeings a year, he believed, the jungle would kill the tea. He remarked that the garden roads in August and September had often grass 3 feet high. He did not believe that ulu grass was disappearing from Assam, or that any change in the grass lands was taking place other than what was being effected by better cultivation. Another gentleman, on the other hand, said that, during his 20 years' experience of Assam, he was convinced a great change had taken place. In support of this he remarked that it was well-known fact that mid- season was much later in most gardens than it was formerly. Tea Pests and Blights. Hoeing and Weeding. Most of the planters present were, however, of opinion that over-culti- vation was distinctly taking place. That surface cutting of weeds did not effect anything more than to temporarily cut them back. That the system of frequent hoeing did not effect any real disintegration of the soil. They agreed, however, with the suggestion, that a better class of weeds carefully selected and encouraged to grow instead of being hoed out, would do good. There is no Sa trees in ......... garden and the superintendent does not think there ever had been any. The soil is very dry and contains only about 0-04 nitrogen, expressed as Ammonia. He, therefore, agreed that Sa might do good, but he would prefer to try mati kalai or some herba- ceous legume rather than a tree, the shade of which was distinctly objectionable. At Patalipam, North Lakhimpur, I had some conversation with Mr. J. Lindsay Alexander on the subject of weeding : " I never hoe the ground before planting. I simply clear the jungle and by kurpe, take out the surface weeds for a space 15 inches in dia- meter, in order to clear a place for the seedlings. And until the period of hoeing I see that the weeds are kept down on these small seedling clear- ances. When the plants are 18 inches high, the ground is thoroughly hoed. This system I have pursued owing to the fact that, in my opinion, the jungle grows less if not hoed. It is also my experience that i growth makes no special effort for existence if left alone." indigenous in. Foreign Weeds. There is certainly much truth in Mr. Alexander's observation of excessive hoeing giving facilities for the growth of a uniform instead of a mixed crop of weeds. A broken loose and empty soil is more likely to harbour seed brought by wind and other agencies than a soil with its natural herbage. Foreign weeds are a greater danger to agriculture than indigenous growth, and an empty soil is sure to become clothed with some exotic, or with one weed covering the entire area instead of the mixed herbage characteristic of all natural growths. To the botanist visiting Assam, nothing would perhaps strike him with greater force than the artificial character of the weeds found on tea gardens. There is a painful uniformity, from one end of the province to the other, and a marked dissimilarity with the adjacent vegetation. In Assam there are remarkably few leguminous herbaceous plants. That family is mainly trees or extensive climbers. In tea clearances, therefore, the entire series of leguminous plants may practically be said to be re- moved. The prevailing type of tea weeds is composite plants, chiefly a purple-flowered Blumea and one or two exotic and pernicious weeds now common to most Indian cultivated areas. Where the cultivation is annual and a rotation of crops takes place, exotic weeds may be said to be infinitely less hurtful than with a perennial crop such as tea : hence the necessity for a more natural herbage. 5 WEEDS. Over-Culti- vation Admit- ted. 3fafi Krttal as Nitrogen Crop. Phaseolus aeonitifolius. Hoeing New Land before Transplant- ing. Artificial and Artificial Nature of Weeds on Tea Estates. Report of Investigations in Assam Drainage of Tea Gardens. DRAINAGE. Objects of Drainage. Solvent of Food Materials. Movement of Water in the Soil. Soils. Con/, with paras. 282- Saturated Soils. Soil Moisture. Capillary Attraction. Conf. with pa* - as. 63, 120. CHAPTER VI. DRAINAGE OF TEA GARDENS. 112. It has been said that "to drain land is to rid it of its super- fluous moisture." That is the most generally accepted idea, but the objects aimed at are to increase the depth and improve the condition of the arable soil. The drainage of agricultural land thus differs essen- tially from that of the streets of a town. The removal of surplus water is undertaken with a definite purpose in view, the fulfilment of which determines the position and number of the drains that may be neces- sary. To understand, therefore, the principle involved by the con- ception of superfluous moisture in agriculture, it becomes necessary to devote, first, some attention to the study of water and its influences on the soil, and, second, to consider the functions it performs in the economy of plant life. XIX. Water and its Relation to the Soil. 113. In the first place, then, water may be said to be the solvent by means of which the food materials of the soil are taken up by the roots. But in addition to water passing into and being diffused through the soil, by virtue of this dissolving power, it is very much more largely drawn down by another physical law, namely, the affinity for water which the various ingredients of the soil possess. All soils, it may be said, have the power to absorb and retain water apart from the temporary disappearance of certain of their ingre- dients in the state of solution. Soils may be regarded as built up of mineral particles of varying sizes and properties with inter- spaces occupied by water and air. No soil, however dry it may appear, is totally devoid of water and air. A soil is saturated when it contains the maximum quantity of water and air that its interspaces are capable of holding naturally. The water is then said to exist as moisture. The absorbing property of a soil is, there- fore, determined by the quantity of water and air that it is capable of holding in the condition of moisture. And this again is regulated by the chemical and mechanical conditions of its mineral particles. Water is diffused through the soil by what is called "capillary attraction," the interspaces act like tubes within which the water is rapidly distributed. The shape and size of these interspaces is Tea Pests and Blights. 67 Drainage of Tea Gardens. entirely dependent on the mechanical condition of the minera particles. But the chemical and physical properties of soil ingre dients aid materially in this absorption and distribution of moisture Sugar will be dissolved if placed in contact with water, but castor oi is neither dissolved nor will it mechanically mix with water it has ni affinity for it. Clayey soils manifest a strong affinity and sandy o gritty soils a very weak affinity for water. Dry clay will absorb from the atmosphere as much as 5 per cent, of moisture in 24 hours while sand, unless in a very fine state of division, will hardly absorb any. Water is thus attracted to, retained by, and distributed within the soil, until the maximum absorbing point has been attained. With clayey soils this is much higher and therefore reached considerablj later than with sandy soils. Soils that soon become saturated ar those that get the soonest parched. In soils with a due portion o clay the moisture rises up gradually from below to replace surface evaporation, and such soils, therefore, dry slowly, because of the strong affinity for water possessed by cl a y. So again clayey soils absorb th night dews, and thus to a certain extent compensate for the dail) surface evaporation by night absorption. During heavy rains an excess over saturation still passes through the soil to the under ground channels of transmission by simple gravitation, but even still very largely in consequence of the peculiar affinity of clay fo water. The excess does not at all events tend so readily to flow on the surface of clayey loams as is the case with saturated sandy soils the ingredients of which possess little or no affinity for water. From these considerations, therefore, it may be said a soil is water-logged when it retains a surplus proportion of moisture over saturation, the surplus existing not as moisture but as actual water. 114. Improvement of t he Soil. Having thus briefly indicated what is meant by superfluous water, it may be as well to similarly exemplify the principles involved in the improvement of the physical and chemical conditions of the soil through drainage. When super- fluous water exists in a soil for any length of time, terrestrial plants are drowned. The effect on the tea plant of a water-logged soil will be at once apparent when it is recollected that, in its wild habitat, it is a native of mountain slopes. By way of illustration, therefore, if wate: accumulates in a tea garden, at a certain depth below the surface, its presence must restrict the extent of culturable soil, for the roots of 5 A WATER in RELATION to SOIL. Soil Affinity fop Water. Sandy Soils. Cow/, with 137, 285, 391. Parching of Soils. Evaporation and Absorption. Vater- logged Soils. raprovement of Soil Conditions. Conf.ivith, par as. 58, 7, 93-4, 128, 282- 313. Culturable Depth estricted by Water. 68 Report of Investigations in Assam Drainage of Tea Gardens. WATER in BELAilON to SOIL. Fall In Temperature. Con/, with paras. Sfi, 93, 10*, 157, Cold Soils Late Crops, Surface Soluble Matter. Soil Improve- ment. Indications of Defective Drainage. Saving in Hoeing. the tea plant will certainly not live in water. It follows that an agency that will carry the water to a lower depth than it might flow naturally, will increase by that extent the culturable depth of the soil. So again should the removal of surplus water from a soil be left to evaporation, many very injurious influences are brought to bear on the crop and on the soil. It is a well-k n own fact that evaporation lowers the temperature. Water, before it can be expanded into the condition of vapour, must obtain a large amount of heat. A badly drained soil that contains an excess of water has its temperature lowered through the utilization of the earth's heat and the absorption of the sun's rays in the accomplishment of evaporation. As the Spring advances and the sun's rays become hotter and hotter, evapora- tion increases and the soil becomes colder and colder. A fall in soil temperature makes the crop late, and hence badly drained soils are cold and late ; perfectly drained soils warm and early. But there is another circumstance that had better be here mentioned. Just as rain carries the soluble materials into the soil, evaporation during the dry season tends to bring these again to the surface, sometimes in the form of saline efflorescence. Should the soil not be porous and readily absorbent, owing to defective drainage, the first heavy showers, with the burst of the monsoons, will carry away these accumulations of soluble matter and thus gradually impoverish the soil. 115. These are surely considerations of the first importance to the tea planter that scarcely require to be further exemplified. It will at once be admitted, however, that the contrast between neighbouring gardens as to the commencement of the flushing season is often very striking. In many instances that difference may be accepted as a prog- nostication of defective drainage in the one as compared with the other. The complaint is often heard that one garden gives a poor return as compared with another, owing to its having a shallow soil. Drainage, while removing the surplus water and lessening the evils of evapora- tion, extends the arable depth to a far greater extent than could be accomplished by the expenditure of the same amount of capital in deep hoeing. 116. The descent of the water to the drains opens up the soil, car- ries air and heat down to the level of the drains, and distributes the soluble materials of the surface throughout the entire stratum per- meated. This is accomplished through the all-important circumstance Tea Pests and Blights. 69 Drainage of Tea Gardens. that the ingredients of the soil (more especially its clay) act as a chemical filter. The warm water charged with the products of surface soil disintegration, and with air (.i.e., Oxygen, Nitrogen, Carbonic Acid, Nitric Acid, and Ammonia), is immediately seized upon and deprived of its food materials. Physical and chemical changes of the soil at once ensue. Poisonous decomposing organic matter is oxidised ; the insoluble iron salts are converted into soluble food substances ; and the nitrogen of the air is brought down to nourish and develop the indispensably necessary nitrating organisms of the soil. Physical modifications of the soil of a no less valuable character also take place. The continuous passage of water through the soil opens it up and thus tends to reduce it to a fine state ot division. Its capillarity is thus vastly improved. By drawing the rain-water down surface wash is prevented. The arable depth of the soil being increased, the roots are able to penetrate to a greater extent and are thus protected by the additional layer of soil from the evil consequences of excessive surface evaporation, and they have the further advantage that occupying a larger extent of the soil they have increased facilities of obtaining food. Plants growing, there- fore, on a well-drained soil are better able to withstand the effects of drought than those on a water-logged soil. A continuous supply of moisture is brought up to meet the .necessities of the plant, the surface soil does not become caked, and in consequence rain when it does fall is at once absorbed instead of being carried away as surface wash. XX. -Water and its Relation to the Plant. 117. Turning now to the second consideration, namely, the func- tions water performs in the economy of plant life, it need hardly be repeated that it is the solvent utilized to facilitate the nutritious solid materials of the soil being absorbed by the roots. As already remarked, when rain falls on a properly drained soil, it carries down to the roots not only the mineral ingredients of the surface (rendered soluble through the action of the sun and air), but also oxygen in the form of air dissolved in the water and, an equally important necessity to the life of the plant, heat, absorbed from the atmosphere and from the warm surface soil. In its descent through the soil the water distributes these food materials of the plant and thus carries fresh supplies to every little fibril. It would be beyond the scope of the present article WATER RELATION PLA NT . Chemical Actions of Rain-water : Oxidation. Conf. with Titrating rganisms . Conf. with paras. 297- 317. Advantages to the Roots. Surface Caking Prevented. Conf. with para. lot. Vehicle of Conveyance of Food. Report of Investigations in Assam Drainage of Tea Gardens. VIMTER RELATION PLA^T. Control Exercised by the Leaves. Evaporation and Transpira- tion. Circulation Dependent on Food Demands. to trace out in detail the further functions oi water, as it next ascends through the tissues of the plant, participates in the phenomena of digestion (or as it is called assimilation) and of transpiration (i.e., perspiration and respiration), and finally once more descends to be ' built up in the growing tissues. But it may be said a free circulation of water in and through the soil is an essential condition of successful cultivation. The minute hairs on the rootlets suck up the moisture charged with nutritive materials. By exuding an acid principle they at the same time decompose and render soluble some of the in- gredients of the soil that are necessary for the plant and which other- wise might not be rendered available. But in their search for moisture and food the roots are not passive agents obedient to mecha- nical or accidental environment. They are directly controlled by the leaves above ground. 118. Transpiration (or as it might popularly be described perspi- ration) takes place literally within the tissue of the leaf and is thus a widely different phenomenon from the drying by evaporation of a piece of damp wood. It is a vital, not a physical, phenomenon. Small mouths called stomata are distributed over the epidermis of the leaves (of land plants), more especially on the under surfaces, and these open into passages that radiate through the cellular structure of the leaf. Water in the form of vapour is given off into these passages and makes its escape through the stomata so long as they remain open. But under certain circumstances they can be closed and transpiration thereby checked. The moment this takes place the demand for fresh supplies of moisture ceases and the rootlets with their absorbent hairs remain inactive or nearly so. Transpiration is necessarily very largely influenced by the conditions of the atmosphere in relation to the degree of humidity in the soil. But these are purely accidental phenomena controlled by physical attributes. A dry atmosphere brought to bear on the leaves of a plant whose roots are in a damp soil should cause rapid transpiration, conversely a damp atmosphere with the roots in a dry soil should retard transpiration. But it must not be forgotten that the circulation of water through the tissue of the plant is primarily in consequence of its being the medium of convey- ance of food. If, therefore, its circulation was governed exclusively by such physical conditions as mentioned, the plant would be surcharged with food materials to an injurious extent and might be even forced Tea Pests and Blights. Drainage of Tea Gardens. to continue the function of assimilation during its periods of repose It will thus be seen that vitality is and must be the power that utilizes and controls the physical laws that are brought to bear on the plant. 1 19. When transpiration is not desired the stomataare closed and the suction within the roots discontinued. But while that is so there can be no doubt that with plants as with animals circumstances often arise that induce excessive absorption of both food and liquid. When that takes place disease must of necessity supervene sooner or later and when once the plant loses its activity, physical and not vital in- fluences predominate until death occurs. It cannot, therefore, be doubted but that an abnormally damp soil is a condition to be care- fully guarded against since it must of necessity expose the plant to an injurious resistance to the operation of natural laws. That the leaves may in consequence become charged with an excess of moisture (a sort of dropsical condition) seems highly probable. It might even be supposed that a too rapid evaporation (transpiration) would in juriously lower the plant temperature. Every one who has given the subject any degree of study is familiar with the sickly appearance of land plants growing on an over damp soil, and it is possible the sun blistering of the leaves to which tea planters often allude is due to this circumstance. 1 20. It will thus be seen that there are good reasons for the affirmation that drainage is undertaken with a two-fold purposes, viz., to remove excessive moisture and to increase the culturable depth as well as to improve the physical and chemical conditions of the soil. It is a mistake, therefore, to suppose that under any circumstance a perfect system of drainage is calculated to dry the soil abnormally and thus to expose the crop to the evil consequences of drought. Actual water only is carried away by drains, and before the excess can reach the channels of exit a far greater depth of soil than would have been the case otherwise has been raised to the point of satura- tion. The capillarity of the soil is vastly improved by drainage no doubt, but the affinity for water (possessed more especially by its com- ponent proportion of clay) is so strong that the presence of an ela- borate system of underground drains will not deprive it of its mois- ture. The deeper portions of the soil part reluctantly in fact with their moisture, and do so only at the demands of surface evapora- tion, not underground drainage. Evaporation is a direct disturbance WATER RELATION PiSn. Excessive Supplies. Resistance to Natural Laws. Disease. Sun Blistering:. Cow/. tHth para. 818. Two-fold Objects of Drainage. etna! Water Removed. mprovement pillarity. Con/, with paras. 63, Soil Moisture Removed by vaporatiou. Report of Investigations in Assam Drainage of Tea Gardens. INDIAN AUTHORS Closed Drains too Expensive. Conf. with uaras. 1O8, ' 157-168. Natural Drainage. Sloping Land Objection- able. in the equilibrium of soil humidity that must be adjusted. The ascending return current of moisture through the soil (caused by surface evaporation) thus brings to the roots the soluble food mate- rials, also the water, air, and heat, which had been carried down and imprisoned within the lower depths of soil through the action of the drains. XXI. Indian Authors on Tea Drainage. 121. Having thus indicated very briefly the scientific principles involved by drainage, we may now turn attention to review the atti- tude assumed by Indian writers on tea-planting regarding this all- important subject. The passages quoted will as far as possible be arranged in sequence of date of publication: 122. Dr. Jameson in his Report of the Government Tea Planta- tions of Kumaon and Garhwal, for the year 1840, says that in open- ing out a garden it should be carefully fenced. " After this has been accomplished, the land is to be drained, if necessary, by open drains under-drainage, for want of means and the expense, being imprac- ticable." 123. Mr. H. A. Shipp, Prize Essay (1865), says : "The best site for a tea plantation is that commanding water-carriage in its vicinity with a good flat, or undulating, lay of land, sufficiently elevated to give a natural drainage, and carefully avoiding all steep localities which are liable to land slips and difficult of cultivation." In his subsequent remarks on " the laying out of a garden " there is not the slightest reference to the necessity for drains of any description, nor to the de- sirability of the rows of bushes bearing a fiexd relation to the natural drainage. Mr. Shipp was a Cachar planter of considerable ex- perience. 124. Colonel Money, Tea Cultivation (first ed., 1870; fourth, 1883), seems to have had but a very crude conception on the subject of the " lay of land " suitable for tea. In consequence drainage was dismissed by him as unworthy of the planter's attention. Surface wash was admit- ted as an evil to be avoided in the selection of a site but which could not be cured. " Sloping land," he says, " is objectionable in the fol- lowing respects. It cannot be highly cultivated in any way (I hold tea will only pay with high cultivation), for high cultivation consists in frequent digging, to keep the soil open and get rid of weeds and liberal manuring. If such soil is dug in the rainy season, it is washed Tea Pests and Blights. 73 Drainage of Tea Gardens. down to the foot of the hill, and if manure is applied at any time of the year, it experiences the same fate when the rains come." But Colonel Money seems to have lost himself in this bewildering pro- blem of the selection of land for tea cultivation with the qualifications of good soil and no surface wash. "Valley land," he adds, "is not good if it is perfectly flat. It will then be subject to inundation and stagnant water. There is nothing that kills the plant so surely and quickly as the latter. Even quite flat valleys can be made sweet by artificial drainage, but to do this a lower level, not too far distant, must exist, and the danger is not quite removed then. Valleys in which no water-course exists, and which slope towards the mouth alone, are to be avoided, for the plants near the mouth always get choked with sand." " To conclude shortly, flat lands can be highly cultivated, steep slopes cannot. Tea pays best (perhaps not at all otherwise) with high cultivation, ergo, flat lands are preferable." Had tea culti- vation in India been restricted to the ideal necessities conceived by the author of this Prize Essay on Cultivation and Manufacture of Tea, India would have made but little progress in the contest with China, for the British market, and Ceylon could have had no place whatever in the world's supply of the commodity. Moreover, the cultivation of land which, while in the state of jungle, may have had no surface wash, but, on the contrary, sufficient sub-soil drainage may, when thrown under a perennial crop such as tea, have both conditions completely changed. 125. Mr. J. F. W. Watson (a planter of experience both in Assam and Dehra Dun) in his Prize Essay (1871) hardly mentions the word drainage except to impress on those about to open up new tea land the imperative necessity and one which he regards as of even greater urgency than facilities of transport, to see that the natural drainage of the soil is satisfactory. At the very end of his essay and as an appendix he alludes to the draining of hill slopes in Chittagong, as a system to check surface wash. 126. In the Tea Cyclopaedia (p. 104) the following occurs: " Drainage is an operation the less a plantation requires the better.' " The tea industry must not be handicapped by expensive expedients being necessary to the full development of the plants/' "Capital and skill applied to the carrying out of schemes of reclamation in densely populated countries, where money is abundant and arable lane INDIAN AUTHORS. erfeetly Flat Land is not Good. Flat Lands Preferable, Cultivation Disturbs the Natural Drainage. Natural Drainage Satisfactory. The Less Drainage 74 Report of Investigations in Assam Drainage of Tea Gardens. INDIAN AUTHORS. Drainage Imperative with one- half Assam Gardens. Drainage Indispen- sable. Sloping Land Con/, with para. 156. Depreciation in Quality of Tea. Con/, with paras. 214, 271-5. Bad Drainage an Enemy of Tea Planting. Open Drains Embanked. scarce, cannot be doubted. But that tea should not be grown and will certainly not pay under such circumstances, is equally certain." Truisms of this nature are of necessity the result of defective know- ledge of actual circumstances. Any one familiar with the tea districts of Assam, at the present day, will agree that artificial drainage is essen- tially necessary with at least one-half, if not three-fourths, of the land now under the crop. Moreover, drainage as a method of increasing the depth of arable soil has been entirely lost sight of in opinions such as those quoted. 127. Mr. F. Linde, Tea in India (1879), savs > "A regular system of drainage in low lying or flat lands and longitudinal drains on hilly lands are indispensable." The drains usually seen on hilly lands are made, for the most part, to catch the soil of surface wash not with the object of preventing a flow of water over the surface. In some case pits are dug in alternating rows across the face of the slope, a practice introduced from Japan. 128. Mr. Samuel Baildon, The Tea Industry in India (1882), in his chapter on the admitted depreciation in the quality of Indian teas, alludes to the constant drain on the soil with no recuperation as the undoubted cause. While he does not apparently recognize drainage as one of the most valuable aids to improvement of the soil, makes the following observation : "Extraordinary results have been obtained by ample draining and heavy pruning combined ; but planters cannot achieve victories without labour. " 129. Mr. G. M. Baker, Tea Planter's Life in Assam (1884), enu- merates " bad drainage " under the heading of " The enemies of the tea plant." " With bad drainage, " he says, " there can be no hope of a successful future for any garden. The drainage difficulty used to be surmounted by making all gardens on the side of a hill ; in fact, every one of the old gardens was made in this way, and it took many years before the'possibility of growing tea on the plains dawned upon the somewhat dense minds of old planters. " 130. Professor Wallace, India in 1887, gives a short account of tea cultivation, but makes no allusion to drainage. 131. Notes on Tea in Darjeeling by a Planter (1888) is the title of an interesting little book that contains many practical and useful hints. " In draining your flats, " he says, " cut cross drains as well as long ones about 3 feet deep, and where embankments and raised drains Tea Pests and Blights. Drainage of Tea Gardens. are made, kill off all crabs that are to be seen as they bore through the walls and sometimes flood the flats. If it is only water from Jhoras or springs you want to drain, embanked drains are much the best, as deep drains will drain the little moisture there is in the soil in April off, and every drop is then wanted, so do not cut un- necessary drains. " 132. DP. J. Augustus Voelcker, Report on the Improvement on Indian Agriculture (1893), under the heading of points of defective knowledge regarding tea cultivation, mentions the extent to which drainage may be requisite as a subject that will have to be looked into. 133. Mr. M. Kelway Bamber, in his work on the Chemistry and Agriculture of Tea (1893), was one of the first authors of special books on tea cultivation who gave the subject of drainage any serious thought. Most of his remarks are valuable and to the point, though I am satisfied he did not urge the matter with sufficient force. In- deed he qualifies his recommendations in almost every direction, as for example by the following : " Of course it is not all soils that require drainage and much harm might be done by adopting it in every case ; easily friable open soils with a free sub-soil, from which the water can easily percolate to a lower level, would certainly not be benefited by it but the reverse. " Personally I should hesitate before saying that any soil could be injured by drainage, though I would freely admit that no great advantage might ensue from certain land being drained. If it has been ascertained, for example, that the sub-soil of a plot of land is thoroughly drained naturally, and that the arable portion above is sufficiently deep for all necessities or could not be deepened by artificial drains, then I should concur with Mr. Bamber. The majority of modern European writers on the subject of drainage might almost be interpreted as saying that it is next to impossible to injure land by draining it. 134- Mr. David Crole, Tea its Cultivation and Manufacture (1897), the most recent and least practical of Indian authors on tea- planting, while neither discussing the advantages of drainage nor attempting to indicate the methods that might be pursued, alludes to the subject as if by accident. " Nullahs or drains, I am of opinion, should run between the rows of tea at intervals of about 30 feet, if the labour can be spared for it ; more especially should they be at such frequent intervals in low-lying localities, or situations exposed to INDIAN AUTHORS. Open Drains Dry the Soil. Over Drainage Urged. Conf. with next page. Next to Impossible to Injure Land by Drainage. Drains to be made if Labour Available. 7 6 Report of Investigations in Assam Drainage of Tea Gardens. Stagnant Water Fatal. A Very Different Opinion Advanced. Drainage Important. Improvemen with Artificial Drainage even when Natural Drainage is Good. the frequently disastrous effects of floods. The men have to excavate these drains with their hoes and a day's work consists of the digging a trench from 24 to 30 yards in length, i yard in depth, and of the width of a hoe, i.e., at least 9 inches in breadth. " As if conscious of having by the above passage too summarily dismissed the subject, Mr. Crole again reverts to it in two other paragraphs, thus : " Stagnant water is fatal to the proper growth of tea, and so tea land must be out of the reach of inundations. It must be borne in mind, however, that friable, open soils, with a free sub-soil, and situated on a fairly high level, would receive actual harm from artificial drainage. " He thus endorses Mr. Bamber's views and then continues : "Theoretically, the deeper the drains are cut and the more there are of them, within reason, the better (subject to the above limitation) ; but in practice it will be found that the small drains should be between a yard and 3 feet 6 inches in depth and about 20 to 40 feet apart, according as to whether the soil be stiff or light ; and, moreover, they should be kept clean, and the silt and weeds cleared out every year, if necessary. " In still a further place he returns to the subject : " It is, of course, very impor- tant to get a perfect drainage system and a good flow for the water. " He offers now no suggestion as to how or in what way a " perfect drainage " is likely to be secured. 135. Both Mr. Bamber and Mr. Crole speak of drains as being of most service when from 3 feet to 3 feet 6 inches deep. It would be interesting to know to what extent lateral or feeding drains exist in Assam that materially exceed 2 feet in depth. By way of con- trasting with half-hearted opinions of the nature quoted, it may now be useful to give here a passage from a paper recently published from the pen of the late Mr. William Pringle. "The evidence available shows that there is always an improvement in the yield of the land where it is thoroughly drained. The ratio of improvement is usually not less than 20 per cent, on soils where the natural drainage is fairly good, and in the case of moors and swamps the land is improved from a state in which it would not grow food stuffs of any particular value to a condition of first class fertility. " 136. Mr. E. C. Schrottky published in 1878 "A Series of Articles on Agriculture with special reference to Tea-Planting " and one of the Tea Pests and Blights. 77 Drainage of Tea Gardens. chapters of that most useful little pamphlet deals with " Land Drain- age." With perhaps the exception of the first edition of the prize essays, all the works mentioned in the foregoing remarks were pub- lished long after the appearance of Mr. Schrottky's pamphlet.* And yet only one writer ( Mr. Pringle) urges with anything like sufficient force the adoption of thorough drainage as essential to successful tea- planting. This is all the more surprising since Mr. Schrottky's words are so full of meaning that one would have expected that in the twenty years that have since passed his recommenda- tions would by now have been accepted axioms with every planter. It is perhaps needless for me to attempt to give passages from Mr. Schrottky's paper to show how completely he understood the true value of drainage. I commend the pamphlet to the planting community as well worthy of careful study. In one passage he refutes the idea that drains dry the soil injuriously in these words, " the drainer's object is to remove stagnant water from the soil only in order to give access to more water." " Most soils are drained, not so much to get water out of the land as to get it into the land. More water will pass through a drained than through an undrained soil ; drainage opening thoroughly even the most tenacious soil, giving a free passage to water through it and thus securing to it the entire rainfall, part of which before, on all but sandy soils, found its way over the surface of the land into ditches and nullahs, carrying away with it some of the most fertilising ele- ments of the soil. " " It is a very common notion, especially among tea-planters, that rain when it comes down in heavy showers is in- jurious and should be carried off the land as soon as possible. They do not consider that rain-water contains most valuable manurial elements, and that the luxuriant vegetation of the tropics is due, to a great extent, to the presence of these in every shower that falls." 137. It may perhaps be admitted, from the perusal of the foregoing remarks, that it was unfortunate the writers of Essays and Manuals on Tea-planting did not recognize the importance of drainage. Had they even urged that in the laying out of an estate and in the * The above remarks were page-proofed before my attention had been drawn to the chapter on Drainage in The Tea Planter's Vade Mecum published in 1885, PP- 61-64. 1 many respects I agree with the views there advanced, but cannot accept " cross drains of only if or j foot deep by 2\ feet wide at top." INDIAN AUTHORS. Drains do not Injuriously Dry the Soil. Drains Carry Water into the Soil. Manurial Value of Rain- water. Conf. with paras. 93, 116. Rows of Bushes in Relation to Natural Drainage. Conf. with Report of Investigations in Assam Drainage of Tea Gardens. SUCCESSFU DRAINAGE Rows of Spacing fop Drains. COM/, uith para. Itifi, Objections likely to be Raised. Springs. Artificial Drainage. Natural Conditions. direction given to the rows of bushes, a direct and fixed relationship should be established to the natural drainage of the soil, much good would have resulted. We should have heard nothing of the controversy as to whether the rows should run east and west, north and south, or diagonally to the sun's path. They would have been so arranged that drains, should they have subsequently become im- peratively necessary, could have been run between the rows as their natural and proper positions. But it was of primary importance from the earliest undertakings, as it is to the present day, that in laying out an estate spaces should be reserved for drains quite as much so as for roads. If found unnecessary these reserve spaces could subse- quently have been planted or, if necessary, furnished with drains con- necting on to and completing a preconceived system. In surveying the land for a new estate or new extensions, the survey officer should be directed to take the water levels with the greatest care and to indicate on his plan the trunk and mains with their chief tributary feeder or connecting drains, required to secure a perfect drainage. The planter with such a plan before him could then easily decide the direction of the rows of bushes and the spaces to be reserved for possible future lateral drains to carry surplus water from the various undulations of the soil to the connecting drains. But it is very likely that the total absence, in the past, of any preconceived plan of drainage may be employed as an argument against a complete reformation of the older gardens, in this aspect of tea cultivation. XXII. Conditions of Successful Drainage. 138. These considerations and recommendations lead naturally therefore to the study of the means by which so very great advantages may be attained, namely, the methods by which water may be most freely distributed and the excess most conveniently removed. Rivers and streams are the great arteries and veins in the circulation of water. Rain-water will percolate through most soils and appear again on the surface in the form of springs. 139. Artificial drainage may be said to be improved facilities in the conveyance of surplus water to the rivers and the substitution of a better sub-soil drainage than may happen to exist in the plot of land under consideration. In other words, improvements in the outflow and in the underground currents. Let it, however, be added these must be developed essentially on the lines of existing natural Tea Pests and Blights. 79 Drainage of Tea Gardens. conditions, sists of : A successful system of artificial drainage therefore con- /*/. Trunk drainage that is to say, improvements in the natural outfall such as deepening, straightening or embanking local streams and the construction of ditches or canals to convey the water direct from the area to be drained to the outflow. 2nd. Underground drainage that is to say, the provision of a system of underground channels or drains intended to convey sur- plus water to the canal that connects with the natural outfall. The water is mechanically as it were drawn down through the soil in consequence of the facility of escape provided by these drains. The depth of soil down to the level of the drains has first, therefore, to be saturated before any discharge can take place, so that drains regulate sub-soil humidity. 1 40. It will be evident from these propositions that the latter with- out the former would be worse than useless, but that the former without the latter might under certain circumstances be quite sufficient. Drains are, in other words, artificial improvements in the sub-soil move- ment of water towards the outflow. The natural drainage in a plot of land may be perfect so far as the peculiarities of the soil and con- ditions of the sub-soil are concerned. It may in fact be practically an island within a quagmire, and its fertility depend therefore on the provision of sufficient and complete trunk drainage. With a very large percentage of Assam gardens I believe the former may be a more pressing necessity than the latter. It is in fact to be feared this necessity has very largely been lost sight of in the selection of land to be thrown under tea. Many gardens, especially those on grasslands, are almost on a level with the surrounding rice fields, the annual inundation of which not only stops all outflow but raises the sub-soil level of excessive humidity to a ruinous extent. Where gardens are on higher and undulated land the hullahs or lower portions should be carefully surveyed and their levels ascertained in relation to the natural outflow. These should then be connected by drains suffi- ciently deep to act as the chief tributaries of the main current. But in many cases it would seem imperative that the outflow should be carried to some distance instead of being discharged into the nearest stream or surrounding rice land. The annual water-logging for months together of many gardens (or large portions of them) through the SUCCESSFUL DRAINAGE. Trunk Drains. Sub-Soil Drains. Regulation Humidity. Trunk Drainage of Primary Importance. Cleaned out and Connected by Drains. So Report of Investigations in Assam Drainage of Tea Gardens. SURFACE DRAINAGE. erlng Itles. Shallow Open Drains. Drains Laid out Sibsequent Planting Bushes. Uprooting Necessary. Con/, with paras. 35, 70, 77, 164, 211, 225, 276, 280-1. Drains Passing over Undulations. local stream obstructing the outflow is a fruitful source of many evils. It is generally held by chemical investigators that stagnant water in a soil checks the formation of nitrates and gives origin to several poison- ous compounds. It is thus most undesirable that tea land should be water-logged even for comparatively short but annually recurring periods. 141. But I am fully aware the contention that a more perfect system of drainage is indispensable to the future of tea cultivation, raises engineering difficulties, that in fact this very suggestion intro- duces a large and a difficult problem. I am convinced, however, that sooner or later that problem will have to be dealt with, if the evils of defective drainage are to be faced. XXIII. Assam Method : Surface Drainage. 142. A system of surface drainage has become general in the tea districts of Assam. Trenches are dug at regular distances throughout the garden and for the most part parallel to each other. These are on the average about 9-12 inches broad and 18 inches to 2 feet deep, and I believe only rarely of a greater depth. In fact I venture to think I am correct in designating these as a system of surface, not sub- soil, drainage. I examined them with the utmost care, and while I admit most willingly that they do a certain amount of good, feel satisfied they fall far short of the actual necessities of many estates. They have been made in the majority of cases long subsequent to the date at which the bushes were planted out, and, owing to the fact that to place them in conformity to the requirements of the land would have necessitated the uprooting of a large number of bushes, they have been run between the rows and in some cases, I am afraid, across the natural drainage. It is not uncommon to find these surface drains extending perfectly parallel for hundreds of feet up and down, over every undulation of the soil, without the slightest deviation or conformity to existing conditions and necessities. In order to allow the current to pass over the higher parts of the estate, these drains are in some places made very deep, at others shallow. But I submit that, while water no doubt may flow along them, they very frequently, I am afraid, obstruct the natural percola- tion of the soil. This statement may be abundantly demonstrated by the fact of the faces of the drains annually falling in on the side opposed to the natural flow. A drain 200 or 300 feet in length of Tea Pests and Blights Drainage of Tea Gardens. the dimensions mentioned could never suffice to carry the water that should find its way there, provided such drains were fulfilling the purpose intended. But I am afraid that in many instances the idea that these drains were even primarily constructed for the transmis- sion of water has been lost sight of, for they might more correctly be described as cess-pools. I may mention one instance where this was exemplified to a ridiculous extent. A large plot of land where the soil was water-logged had been surface drained in each direction between every third row of bushes until, as I told the manager, he had made a land and water draught-board of the plot. On enquiry as to the provision of a trunk drain to the outflow I found none had been made and the system of cross drains had been gradually worked into the parallel arrangement that radiated around this specially low portion of the estate. 143. Examples of this nature are fortunately, however, but excep- tional, and on the whole the surface drainage now fairly general may be said to have improved some Assam, estates. But I think it as well to emphasise the fact that at best it is only a system of surface drainage not very different from what I have already characterised as street, in contradistinction to agricultural, drain- age. In many gardens the managers are fully aware of this fact and bank up the earth on either side of the drains and also, just before the commencement of the rains, give the surface soil a heavy clod hoeing By these means it is held that the water is made to percolate through the soil and to find its way to the drains without washing over the surface. I find, however, that Mr. Bamber takes a very, different view. While accepting the present system of surface and open drainage as suitable to the hand cultivation that prevails, he adds, "The soil which is removed from the drains at the time of digging, and when being cleaned, will be found of much benefit to the bushes around which it is thrown, both as a manure and as a means of checking the growth of weeds for a time. It should always be spread as evenly as possible at some distance from the sides of the drains so that the soil .may slope towards, and not away from them, and care should be taken in hoeing, that a few inches of uncultivated soil should be left en either side of the drain to prevent the dis- 1 turbance and falling in of edges." In the above quotation the .j 6 SURFACE DRAINAGE. Cess-pools. COM/, with l>ar>i. 159. No Outflow. Surface Flow Prevented. Conf. with paras. 94, oa, UK, 124, , 127. Drains Banked up. Compare with Tea Planter's Vade. Mew > , pages 62, 64. Lateral Encasing Walls. Conf. with learns. 14-1 and 149. lard Sloping to the JJrtins. 82 Report of Investigations in Assam Drainage of Tea Gardens. SURFACE DRAINAGE. Embanking Drains. Percolation through the Open Drains Mischievous. Surface Drainage Prevented. COM/. tHft para. 143. Shallow Drains. Cow/, u-ith foot-note to para. 136. Ruinous Loss of Vitality. Feeding or Lateral Drains. italics are mine and the words have been so rendered in order to draw attention to an opinion to which I take exception. Everything should be done to cause the water to percolate through the soil. Rather than that the land should slope to the drains I should recom- mend the sides to be banked up and the surface made to slope away from, rather than toward, the drains. 144. It may be instructive to contrast with Mr. Bamber's approval of shallow surface drains, Mr. Schrottky's views. "Speaking of Land Drainage," he says, " we must not be understood to mean the shallow surface drains which are now almost universally used in tea and coffee plantations, to carry off any heavy rainfall, as soon as possible, to the nearest river. Nothing could be worse than this ; what we mean is, a thorough sub-soil drainage, acting 3 or 4 feet below the surface, and capable of absorbing into the soil all the rain granted by the bounty of nature, and either con- sisting of closed pipe, stone, or brush-wood drains, or of open drains with good embankments to prevent all surface drainage. Every precaution should be taken to retain in the land all the rain that falls on it, until it has had time to percolate through the soil and impart to it all the manurial elements it contains." So again he says, " It is a very common fallacy entertained by planters that shallow drains, say 1 5 to 1 8 inches deep, are as effective as deeper drains. This notion should be got rid of as soon as possible, for it is replete with mischief." "Of what use can shallow drains be, 15 or 1 8 inches deep, generally without embankments?" " Their only use, as far as we can see, is to encourage surface drainage and wash out the roost fertile portion of the soil. Some tea gardens have been ruined by shallow drains." These words were penned close on 20 years ago, and I am afraid they are very nearly as true to-day, of the Assam gardens, as ever they were, except that the ruinous action of open shallow surface drains has been continued to a greater extent and the disease and loss of vitality foretold by Mr. Schrottky, become a reality with many of the older concerns. 145. According to the most generally accepted opinion in Europe, a useful and effective system of feeding or lateral drains should be at least 3 if not 4 feet below the surface, so that the drainage becomes sub-soil. That is to say, the water derived from rain is made Tea Pests and Blights, Drainage of Tea Gardens. to penetrate through the soil to a depth sufficient to reach the deepest roots before it is removed. If drainage 4 feet below the surface be deemed essential in the cultivation of annual and herbaceous crops, it follows that it is doubly more so with a perennial and bushy crop such as tea. Thus even admitting that by banking up the soil and clod hoeing, a surface flow to the drains may be prevented, the system of drainage that prevails in Assam tea gardens is one that must create a very shallow percolation of the soil. Hence it may reasonably be concluded that either the open drains described do not fulfil the purpose of drains, or if they do, they remove the water at a point above the level of the major portion of the young absorbent roots of the tea plant and very possibly leave the soil water-logged below their level. 146. I am afraid also that an elaborate system of open drains tends to dry the soil to an injurious extent. Mr. Bamber, it will be observed, recommends that a strip of soil (which in practice is from half to a foot in thickness) should be carefully preserved on the sides of the drains. This recommendation is very generally followed with the result that these lateral ridges become retaining walls. After a few seasons they become practically impervious to water. They are then coated with ferns and other vegetation, and I fear harbour to a very large extent the hibernating stages of a good many of the tea pests. 147. But Assam falls far short in extravagance in this respect to a garden visited by me in Kangra. There the drains are not only 4 to 6 feet deep but nearly as wide. At first it looked as if they had been intended as secret passages constructed for some ancient strate- gic necessity. I was told they were drains that served the further purpose of furnishing additional surface soil to the intervening culti- vated plots. I have seen nothing to compare with these, except perhaps the mulberry beds in the Bogra district. The stunted bushy cultivation of that plant, could not be accomplished unless the roots were above the level of the annual rice-field inundation. Immense labour was accordingly expended, the soil was excavated from strips of land some 8 to 10 feet in breadth and thrown up on intervening spaces of like dimensions. Elevated beds were thus formed some 4, 6 or 8 feet above the intervening portions. On the lower spaces rice was grown and on the higher mulberry. But, can it be matter of surprise that, where such conditions were necessary, the industry stood 6 A SURFACE DRAINAGE. Shallow Percolation. Drying of the Soil. Con/, with paras. 147 and 162. Pests Harboured in Open Drains. Con/, with para. 72O. Unneces- sarily Large Open Drains. Mulberry Cultivation. Report of Investigations in Assam Drainage of Tea Gardens. SURFACE DRAINAGE. Obstruct Sub-Soil Percolation, Water- logged Basins. Dry the Soil Injuriously. Con/, with paras. 146, 162. Equilibrium of Soil Moisture. Lateral Retaining Walls. Com. ii'ith para. 143. Demonstra- tion of Value of Drains. a poor chance of becoming either lucrative or lasting. The mulberry beds are being abandoned and the silk-rearers are in a state of 'poverty. 148. I have little hesitation, therefore, in affirming that open shallow drains of the nature indicated, do not serve the purpose of sub-soil suction, but, on the contrary, encourage a surface wash of the rain- water toward these superficial channels of escape. I should not indeed be surprised to find that in many cases, as already suggested, these drains entirely obstruct the natural sub-soil percolation and convert the intervening plots into water-logged basins. That they dry the surface abnormally I have little hesitation in affirming. Let any one work out the amount of soil (on a level with a certain pro- portion of the roots) that is exposed in these drains to the merciless heat of the dry season, and he will be surprised at the very large per- centage obtained. It should be recollected that in a healthy soil a complete adjustment is constantly taking place from particle to particle. When the roots of the plant abstract moisture from one spot, all adjacent portions immediately part with the necessary amount of humidity to restore the balance. So in the same way if an open drain has its sides and bottom dried abnormally from exposure to the sun, the adjacent soil parts with its moisture to replenish the loss and restore the equilibrium. 149. The simple fact that the sides of these drains are never culti- vated, increases the difficulty, for a cultivated surface suffers less by eva- poration than an uncultivated one, while it is at the same time more absorbent. If I am not, therefore, very much mistaken, the injury done to the tea land during the hot season, by these elaborate open- ings into the soil, must be quite as great as the damage they occa- sion, through the tendency of a surface wash toward them during the rainy season. That they certainly are not sources of moisture to the tea, may be abundantly demonstrated by the fact that the roots are never found to penetrate through or even approach the enclosing walls of these drains. That they do not deepen or improve the qual- ity of the soil, may be still further seen by the fact that the rows of tea bushes hard by manifest no superiority to those at a distance. And this last observation is significant, for most people are familiar with the 'bands of bright green grass or richer corn that in Europe correspond to the pipes that are lying 4 feet below the surface of a well-drained field. Tea Pests and Blights. Drainage of Tea Gardens. XXIV. Position of Drains. 150. In most Assam gardens the construction of receiving drains to connect with the main outflow, has no doubt been carefully con- sidered, but in some few instances, examined by me, receiving drains had been entirely neglected or placed in wrong positions. The receiving drains should of course occupy the lowest portion of the ground and the sub-soil drains should follow the line of the greatest ascent and run parallel to each other or converge toward the bottom, as necessity may dictate. It is no doubt sometimes also of advantage that the feeding drains should pursue a diagonal course, and thus enter the receiving drains at an acute, not a right, angle. Undulating land can never be satisfactorily drained by a fixed direction being laid down for the sub-soil drains, in defiance of surface configuration. Each depression must be drained by itself and have a central receiving drain traversing the lowest portion and connected with all the other receiving drains. It is essential also for a rapid flow of water that the sub-soil (or lateral) drains on either side of the receiving drain should not discharge opposite each other. 151. Distance Apart. As to the distance apart of lateral or feeding drains, the following table was given by the late Mr. Pringle (derived from Mr. Dempsey, C.E.) as the final results of English experience : Nature cf Soil. Depth of Drains. Distance apart. Compact. 2 feet 6 inches. 15 feet. 2 Q 18 Soft free clay . . Me Jin 'ii. 2 Q 30 21 >, 21 ,, 27 )> Friable .,..,. 7 7 3 Porous. Light loam Sandy 3,6 7 Q 33 39 Light gravelly sand . . 4 ' 4. 6 5' 60 POSITION of DRAINS, Outflow. Adaptation to Configura- tion. Lateral Feeding Drains. Con/, with foot-note to para. 136. 86 Report of Investigations in Assam Drainage of Tea Gardens. POSITION of DRAINS. Fall in Lateral Drains, Depth the Important Factor. Nature of Sub-Soil. Open Drains made to Bushes Rising out of Ground. Con/, with para. 216. Ruinous Surface Wash. Conf. u-ith paras. 94, 9y, 116, 124 J27, 137, 21V, 271. Three feet should be the minimum depth of lateral drains, on good average tea land, the mains or connecting drains should be correspondingly lower. The lateral drains should, if possible, have a fall of i in 100 or i in 150; Mr. Schrottky fixes the minimum at i in 220. Mr. Pringle, who was for some time Agricultural Chemist in Coorg (under Messrs. Matheson & Co.), seems to have been in favour of open drains for coffee and tea plantations owing to the liability of closed ones being blocked by the roots. He adds, "wing drains need not exceed i foot 6 inches at top by 4 to 6 inches at bottom. Depth is the important factor, not width." 152. Nature of Sub-Soil. In Europe the practice prevails of digging deep holes in order to study the nature of the sub-soil before commencing to lay out drains. So far as I was able to ascertain from the study of the cuttings made for railways and roads, the better class tea soils of Assam are often of an enormous depth and of a uniform nature throughout, namely, a rich red or yellow clayey loam. This circumstance no doubt may necessitate certain departures from European agricultural practice. But that open drains should be made professedly to facilitate surface wash, as I was, on more occa- sions than one, informed was the case, is a very radical departure indeed. I was repeatedly assured that the natural drainage was quite sufficient. This was more especially said to be the case when the drains were run across the face of sloping land instead of up and down or diagonally. 153. Bushes Rising out of the Ground. While not doubting that there may and indeejd does exist in many cases a distinct necessity for terrace cultivation, I would most emphatically take exception to the statement that drainage is unnecessary. Hardly a garden could be said to exist in Assam where surface wash does not or had not taken place. This is of course more especially the case on all land with a slight declivity. The bushes that once had been securely rooted in a deep soil may now be seen standing on the top of a cluster of roots, so that the stem, Mangrove-like, is i or 2 feet above the level of the ground. And this is by no means confined to sloping land, but may be witnessed on all flat land where free percolation does not take place. The surface soil has been washed away and the bushes thus made to rise as it were out of the soil. No more certain indi- cation of ruinous surface wash could be mentioned. Tea Pests and Blights. Drainage of Tea Gardens. 154. Bushes Seeming to Subside. Interference with the natural drainage may, on the other hand, be seen to produce a subsidence of the soil around the bushes. At a garden in the Sibsagar district, visited on the nth April, the observation was made that one-half of the estate on the north side of the Ali ( or road ) was much inferior to that on the south, and, moreover, appeared water-logged. It- consisted of a heavy red sandy loam and was mostly under China and inferior jat Assam hybrid bushes. The water was seen to collect on the surface into pools, and owing to the impervious nature of the soil to finally gravitate towards the bushes. The roots then served to conduct it below until, through this continual subsidence, the ground around the bushes become the lowest portions. Large holes, often a foot in diameter and i| feet deep, were thereby excavated with smaller passages leading from bush to bush. This condition was frequently observed in gardens where the drains might be said to follow method- ical system -of parallels regardless of the local undulations and natural drainage of the soil. In a garden with impervious soil where water tends to flow on the surface and to use the stems and roots as conductors to the sub -soil, thorough drainage and even drill hoeing would appear imperatively necessary. Though due doubtless to a slightly different state of affairs to that in which the bushes instead of appearing to sink into depressions are seen to stand above the surface, both denote defective drainage. 155. Sites of Assamee Villages. In this connection I may also mention a very evident example of defective drainage. Planters are familiar with the fact that plots of land here and there, in very nearly every estate, are barren or practically so. These are generally explained as being old sites of Assamee villages or coolie lines. It is a well as- certained fact that land on which human beings have resided for any length of time is sterile. This is, however, not due entirely to the ac- cumulation of poisonous organic materials. It is a direct consequence of the soil having been so compacted that it is impervious to both water and air. Such soils may be repeatedly deep hoed and even richly manured, but will still take many years before the tea bushes planted on them show any indications of activity. Let one or, if necessary, two good sub-soil drains be run through such plots, and in a comparatively short time they will be seen to have been converted POSITION of DRAINS. Seeming Subsidenca of Bushes. Roots Conducting Water below. Defective Drainage Indicated. Old Assamee Villages. Conf. with para, 312. Drainage Report'of Investigations in Assam Drainage of Tea Gardens. POSITION of DRAINS. Drainage of Hill iides. Coitf. with para. 137, also Tea Planter' rade JUernm, p. 63. Sub-Soil Drainage Checks Surface Wash. Increase the Arable Depth. Sandy and Porous Soil with Low Organic Matter. Con/. ,rith parti*. 96, 113, 285, Hit!. into pieces of the very best soil. The oxygen of the air ( drawn down by the water) will rapidly convert the accumulations of organic matter from a poisonous to a highly nutritious condition. The water both through its chemical and physical properties will open up the soil and render it arable to the needed depth, and thus drainage as a means of tillage will be demonstrated to succeed where the hoe had failed absolutely. 156. Sloping Land. Sloping land, it is often said, cannot be thoroughly cultivated because of the very certain removal of the loosened soil that would take place by surface wash. Far from drain- age therefore, being unnecessary on sloping land and hill sides, it is just in such situations wheie it may be of most pressing urgency. A rapid vertical percolation into a liberal sub-soil drainage will stop surface wash more effectually than terrace cultivation or Japanese cess-pools to catch the soil. XX V. Sub-Soil or Pipe Drainage Recommended. 157. The most effectual check in fact to surface flow of water is a liberal and deep percolation and rapid sub-soil removal of surplus water. Indeed I attribute the backwardness of many gardens or por- tions of gardens as due primarily to the cold, sour, and water-logged condition of the soil. I would strongly recommend experiments to be made in sub-soil draining, especially with heavy soils of great depth and with shallow sandy loams where surface wash has been clearly established. I was taken over a garden in Upper Assam where the yield had fallen off within the past few years by one-half its former record. The decline had been steady for a number of years back. Various reasons were assigned by the superintendent for this circumstance. The soil was so extremely sandy and porous that ooen drains, such as had been introduced in other estates, could not be maintained. The real explanation no doubt is the shallowness of the soil and the continuous loss during the past number of years, through surface wash. Sub-soil drainage would, in a case of this kind, .induce a -venical instead of a lateral flow of water and thus give a greatly needed deeper fertility .and humuiity than at present exists. 158. Cultivation of the nature pursued in Assam must tend to break up the ingredients of the surface and thus gradually increase Tea Pests and Blights. 89 Drainage of Tea Gardens. the evil tendencies by the production of a soil that cannot retain suffi- cient moisture to meet the necessities of the crop. No wonder there- fore when an originally light sandy loam after 40 or 50 years' conti- nuous cultivation of the same perennial crop begins to show signs of losing its fertility. It has been hoed some eight or ten times every year without the slightest effort having been made to deepen the arable stratum. Year after year its soluble materials have been brought to the surface and washed away by the heavy and sudden rainfall that often alternates with hot dry days. No manure has been given, no rotation of crops pursued. A persistent system of hoeing has been looked to as the one requirement for a never ending pro- duction of tea. 159. Objections to Pipe Drainage. While fully conscious that my views on the matter of sub-soil drainage are likely to be opposed to those of the majority of tea-planters, I think it as well nevertheless to impose thereby no restrictions on my freedom of utterance. But it may be as well to record here the opinions of the few authors who have expressed themselves on the subject of pipe drainage: M r. Schrottky comments on the subject in the following passage : " Pipe drains cannot be used, as the roots would invariably choke up the pipesjbut closed stone or brush-wood drains are practicable." I fear that in Assam stone drains would be an impossibility from the fact that there are no stones to be had in tea gardens. Brush-wood drains I certainly could not recommend owing to the fact that they would most certainly harbour and encourage the development of \\hite-ants. But to continue from Mr. Schrottky, " The fall in such drains, however, ought not to be less than i in 220. The drains will of course converge to the nearest river, nullah or jheel ; where the plantation lies in a hollow and no outlet can be found for the drains, drainage can be often established by digging a few wells and estab- lishing a connection between the surface and some porous sandy substratum. This plan will also answer where the garden is so sur- rounded by rice kheis and villages, as to prevent access for the drains to any nullah or river. All drains should, of course, be con- structed on the fundamental principle that water runs to the lowest level and a previously well-considered plan should underlie all opera- tions. " Mr. Schrottky's remarks on the subject of drainage into wells are worthy of careful considerat'on. PIPE DRAINAGE. Surface Tillage. Surface Wash. Persistent Hoeing. items Drains. Con/ 1 , ivilh Tea Planter's rade Menu m, p. O3. Brush-Wood Drains. Fall in Lateral Drains. Drainage into Wells. Report of Investigations in Assam Drainage of Tea Gardens. PIPE DRAINAGE Objections Penetration of Roots. Vermin. Objections See letter by " A Novice," Tea Planter's Vade Menum, p. 64. Con/, with P*9* 77. 160. Mr. Bamber narrates the objections to pipe drainage in the following passage : " The question has been raised as to the possi- bility of using pipe drainage for tea, and so doing away with the open drains. Several advantages would be gained by its adoption, but there are also several objections to it, the most important of which is, that in the dry season the roots of the tea-bushes would certainly penetrate the joints of the pipes, wherever water was to be found, and rapidly choke the drain ; and it would be very difficult to discover the exact spot where the stoppage had occurred, without opening the drain in several places throughout its length." " Vermin, white-ants, etc., would also be liable to damage the drains, by excavating the soil below the pipes, when they would drop out of their proper level, and so prevent a free flow. In the case of such an accident the faulty spot would probably be shown by the water rising to the surface as a spring, during- any very heavy rainfall." 161. The only other writer who deals with the subject of covered drains * for tea plantations (so far as I can discover), is the gentleman whose letters to the Madras Mail I have already placed under contri- bution, namely, the late Mr. William Pringle. "Open drains," he re- marks, " are more suitable for plantations than closed ones laid with pipes, which are liable to be blocked by the roots of the trees." 162. I have already detailed the chief objections that exist to open surface drains. One of the most important is the injurious drying of the soil that must take place. Were the lateral or feeding drains to be lowered to 3! or 4 feet, they might, and no doubt would in that case give origin to a satisfactory sub-soil percolation, but their drying pro- clivity would only be the greater by the increased depth. I repeat drains are intended to remove surplus water, not to deprive a soil of its natural moisture. It seems to me, therefore, that in the Tropics the surface soil should not be exposed to any additional influences that may dissipate its humidity than occur naturally. I should like to know, however, if covered (pipe) drains in tea land had ever been tried. I came across no one in Assam who could tell me of any experiments in that direction, and consequently could obtain no evidence that they had been found defective in the way * The Tea Planter's Vade Mecum says, the trifling rain-fall in England renders pipe drainage practicable : some of the tea districts would have to dispose of at least five times as much rain-water. strictly speaking, correct ? Is this statement, Tea Pests and Blights. Drainage of Tea Gardens. indicated by Messrs. Schrottky, Bambep,and Pringle. I am not pre- pared of course to say that these gentlemen have been reasoning on purely theoretical grounds, since in Europe the rule is laid down as absolute that drains must be kept at some distance from hedges or trees. But the tap root of the tea plant goes straight down into the soil, and the laterals to the best of my knowledge do not cover more than a space of 5 feet in diameter. The greatest diameter, more- over, occurs at about 2 feet below the surface, lower down the laterals become shorter and shorter until they practically disappear. It is customary to say that the roots of a plant spread below ground to a slightly less extent than the branches above. The dome of leaves and branches is intended in fact to act like an umbrella con- veying the rain to the part of the ground as near as possible right above the young growing roots. 163. Scheme for Pipe Drainage. To drain effectually and at the same time to obviate the danger of the roots disturbing the pipes it no doubt would be necessary to uproot one row of bushes where the required distance apart did not already exist. I do not suppose, how- ever, that with bushes 7 feet apart there would be the slightest danger of underground drains, at a depth of 4 feet below the surface, being in any way injured by the roots of the tea. I have had many tea bushes partly or entirely dug up, in order to see the extent to which the roots pene- trate and spread laterally. I have no doubt but that with good drainage and a rich sub-soil, the tap root might descend 6 to 10 feet or even more, although I never come across a bush the main root of which materi- ally exceeded 5 feet. Indeed I was greatly surprised at the shortness of the roots and at there being so very few of them as compared with the number of branches a circumstance that is probably accounted for by the severe and constantly repeated pruning to which the plant is subjected. 164. It would of course be disastrous to plant tea bushes on the top of drains, in the way wheat or turnips are sown in Europe. But not a few gardens in Assam, even at the present day, have their bushes 7 or even 8 feet apart in one direction. In most cases such gardens have been or are being interlined with young bushes. I have no doubt but that covered drains between every fifth or sixth row, in a garden of the nature indicated, would be perfectly safe. The land would be thoroughly drained and for many years to come would ffiK DRAINAGE. Relation of Roots to Branches. Conditions Necessary. Number and Extent of the Roots. Bushes must not be Planted on Top of Drains. Report of Investigations in Assam Drainage of Tea Gardens. entail no further trouble or expense on this score. Where bushes stand only 4 feet apart there no doubt would be some risk in the roots disturbing the pipes. Deep covered sub-soil drainage in that case might mean the uprooting of a row of bushes to allow of the drains being placed and maintained in position. But I think there can be little doubt as to the fact that defective drainage has largely to account for the rapid development of the blights and diseases of the tea plant. The improvement effected by good drainage would more than repay the loss sustained by the removal of the bushes necessary to allow of a complete system being introduced. 165. I would strongly recommend all extensions or new gardens to be laid out in the future with provision for a liberal system of sub- soil drainage, in direct adaptation to the conditions of the soil and the configuration of the land. It would be no very serious loss, where the bushes are 5 feet apart, to plant each sixth row, or where they are 4 feet apart, each seventh row, 8 feet apart instead of 5 or 4 feet as may be the case with the others. Were this system followed, sub-soil pipes placed 4 feet below the surface and running along the middle of these blank spaces would approximately occur every 32 or 34 feet. The space above the pipes would be found convenient for the work people on which to place their children, also baskets and other collecting materials and agricultural implements that often are at present thrown down between the bushes and do considerable damage. These alternating strips might also be utilized for the cultivation of nitrogen giving leguminous crops. And indeed even should sub-soil pipes never be placed within them they would afford a greatly needed ventilation to the garden. 1 66. From all I was able to learn in Assam the chief causes of the want of vigour and prevalence of pests might be said to be defective drainage, excessive plucking, absence of any rotation in crops, want of manure, and overcrowding. If I be correct in that opinion the loss of every sixth or seventh row of bushes would be of small conse- quence. The increased yield, due to the deepening and improving of the soil, would more than compensate for a loss even of so serious a nature as that proposed. But in my opinion the time is rapidly approaching when such losses will have to be accepted. 167. Mr. Bamber considers white-ants as likely to disturb pipe drainage. I cannot see how this could come about. In many tea Tea Pests and Blights. Drainage of Tea Gardens. gardens it would be difficult to find a white-ant hillock anywhere. But apart from the fact that they would have to be fairly common in gardens now before they could be regarded as likely to prove a positive danger in the future, there are other circumstances that I think should instantly dispel that anticipation. I have had several ant hillocks out open in Assam and never found one yet in which the ants were more than 2 or at most 3 feet below the surrounding surface level of the soil. Their hillocks may be as much as 3 to 8 feet above, but they rarely penetrate to any great depth, though their lateral burrowings are often marvellously extensive. The mere fact that pipes would be damp and the ground around them porous and traversed by the water passing to the drains, would render such posi- tions unlikely ones for white-ants to take up their abode. Were the pipes to be made of wood instead of clay it might be different. 1 68. Coat of Pipe Drainage, I confess I can see no sufficient reason why tea gardens in Assam should not be pipe-drained.* The difficulties that exist are those alone incident to all departures from established usage, and once the subject has been viewed as one that must be surmounted, one difficulty after another will disappear. I am of course fully aware that pipe drainage would be expensive. Assum- ing that 6-inch clay pipes could be put down at 8 annas per running foot, and that it was found necessary to have drains every 30 feet, that would mean 1,450 running feet per acre, or 8750 against R4O for the open surface drains at present in use. But I have repeatedly remarked, and desire here to reiterate, that my object in writing this report is to indicate the probable causes and possible cures of the lea pests. The financial aspects of the questions raised I leave to those whom it may concern. I would, however, point out that the expenditure for surface drainage is a frequently recurring one, while pipe drains, if successful at all, would be permanent. Moreover, they would discharge the object aimed at so infinitely more satisfactorily that I am fully convinced they would in the end be found economical rather than extravagant. If it will pay to drain wheat fields it ought surely to pay to drain tea gardens. Moreover, there is no reason why clay pipes could not be made locally and at a third the price estimated, or even less than that. But it is useless to argue on probabilities, PIPE DRAINAGE. White-ants. Confrwith pava. 665(3). * See Report of an experiment at pipe draining a Vegetable garde Assam Jo-urn. Agri.-Hort. Soc. Ind. Vol. IV. Proc. nth July 1845. garden in Financial Considera- tions. Con/, with, paras.t O8, Renewal of Drains. Conf. with para. 169. Advantages. 94 Report of Investigations in Assam Burying of Primings in Drains. BURYING PRUN/NGS. Experiment Necessary. In Drains. By Trenching. Position of Bushes made to Govern Drainage. Renewal of Drains. Con/, with para. J 68, Burying Primings Recom- mended. fonf. tvith para. 699. to me the suggestion seems well worthy of trial. I would, therefore, urge the owners and agents of tea gardens to accept this recom- mendation as one to be seriously considered. As I have shown it would not cost a very great deal to have 20 acres or so, drained in the manner recommended. Careful returns of the plot experimented with, if preserved before and after, would in a very few years demonstrate conclusively the utility and practicability of sub-soil drainage. XXVI. -BURYING OF PRUNINGS IN DRAINS. 169. Before concluding these remarks on drainage I desire once more to take exception to another of Mr. Bamber's recommendations. " It is the practice," he tells us, " on several gardens to bury prunings in the drains, after they have been open some years, and to dig new drains between the next row of bushes, utilizing the soil removed to fill up the old drains. This burial of the prunings, the leaves of which contain a large amount of nitrogen, is no doubt of much benefit to the bushes in the immediate neighbourhood ; but, if the drains have been dug originally the right distance apart, it would probably be found more economical to spread the prunings evenly and trench them in with a double hoe than to incur the expense of re-digging all the drains." The mere fact that such a system exists of periodically changing drains from between one row of bushes to another shows that it is the existence of bushes that governs the position of drains, not the configuration of the land and nature of the soil. When once placed in their proper positions, drains should not be changed, unless through distinct indications of deficiency in the drainage. The pores of the soil having been so adjusted that water has found its way toward drains, in particular positions, a disturbance of those positions would retard for some time the percolation and thus do positive harm. Apart, therefore, from the expense of renewing many thousand feet of open drains, with no compensating advantage, there are distinct reasons why the practice should be discontinued. 170. My chief objection to Mr. Bamber's remark on this subject lies, however, in the fact that, instead of condemning the habit of bury- ing prunings as dangerous, he recommends it and, moreover, suggests an even more pernicious system of doing so than that to which he takes exception. But I regret to say Mr. Bamber is not singular in this Tea Pests and Blights 95 Burying of Primings in Drains. opinion. Most writers on the subject of the disposal of prunings either recommend that they should be buried or view with indifference the fact of their being buried, Colonel Money says, "Let all prunings be buried between the lines of plants, if possible, before the leaves have been withered. They make capital manure, but much of the virtue escapes if they are allowed to lie on the ground any time before they are buried." Mr. C role says, " Heavy prunings are generally buried in trenches specially cut for them between the lines of tea, at intervals of two or three rows or more, in order to act as a sort of green soil manure ; but as some planters fancy that this method does not conduce to the health of the plants, but makes them prone to blight in some unaccountable manner, the prunings are sometimes carried away and burnt." He then goes on to say that the men do the " cutting down as the heavy pruning is called, and the women the other lighter pruning. After the pruning is over and it is always well to get through with it as soon as possible the men double-hoe the soil ; that is after turning up the top sod with the hoe, they hoe up the soil beneath, scrape the prunings into the shallow trench thus formed, and bury them below the sods of the next lot in front that they hoe, thus securing all the benefits from the manuring properties of the otherwise useless prunings." 171. Dissemination of Disease. But for the use of such ex- pressions as " fancy " and " unaccountable " applied to a question of this nature, I should have regarded the burying of prunings as one that had only to be mentioned in order to secure that the practice would in future be rigorously prohibited. Even admitting that there is a slight manurial advantage by so doing, some of the most serious maladies to which tea is subject is thereby distributed all over the garden. It will pay the planter ten times over to incur the expense of purchasing a chemical manure, that will give to the soil as much, if not more, nitro- gen and other materials than are contained in the prunings. By bury- ing them he risks the perpetuation and extension of many insect and fungoid pests that harbour on the shoots when the periods of their inactivity occur. 172. In a garden in the Tezpur district visited by me in July, 1 pulled out of the ground many projecting twigs of partially buried prunings, and showed the manager, who was with me at the time, that these contained, in their active condition, the spore-bearing structures Report of Investigations in Assam Burying of Prunings in Drains. BURYING PRUNINGS. Thread Blight. Conf. with paras. 830- Poot Fungi. Conf. with paras. S75- 81. Sappophytlc then Parasitic. Burning. Conf. tHth para. 213. Drying Prunings Langerous. Ashes used as Manure. of " Red Rust." These prunings had been buried in the Autumn and had thus continued for months to distribute the disease. Red-rust had made its appearance in the garden a few years previously and had been spreading at an alarming extent, and no wonder since year after year, by burying the prunings the malady had been carried from affected to healthy bushes. 173. On another occasion (in June), while examining a garden in Sibsagar district, the manager at my request dug the ground around a bush where thread blight was seen to run up the stem, as if extend- ing from the roots. It was soon discovered, however, that it was spreading from buried prunings. 174. I might multiply such examples, but the instances given will suffice to show that surface trenching of prunings is a most dangerous proceeding. If thrown into drains aH completely covered with 2 to 3 feet of earth, the evils to which I allude might be greatly mitigated. But, as opposed even to this, it may be said, there can be no doubt, that the roots of the tea plant are often invaded by fungi that would seem to originate in the first instance on the roots of dead trees and other decomposing vegetable matter in the soil, being what the bota- nist calls saprophytic in the first stage of their existence (and thus harmless to living plants), but assume a further stage in which they are parasitic and kill the plants upon which they then live. Surely with possibilities of this nature it should be regarded, under every circumstance, as dangerous to bury tea prunings. They should bp collected into heaps on the roadways and invariably burned, the ashes being scattered over the surface of the soil. Ar,d let me add that in gardens badly blighted, the burning should not be delayed until the prunings have dried. By so doing the blights contained on them mature rapidly in order to check their approaching destruction through the death of the prunings. Their germs are at once distri- buted and the evil it is desired to intercept is thus more widely dis- seminated than might otherwise have been the case. It is desirable that each day's prunings should be burned at once even should they be only charred and the leaves and twigs alone actually burned, In that condition they are comparatively harmless and the coolies might then, if they desired, be permitted to carry off the larger portions for firewood. Finally, when fully dried, the remainder should be com- pletely burned and the ashes scattered on the garden soil as manure. Tea Pests and Blights. 97 Pruning. CHAPTER VII. PRUNING. XXVII. Diversities in Pruning. 175. Pruning is an operation performed in horticulture to induce a plant either to assume a particular shape that it might not do natur- ally or to force it to concentrate its energies in a direction it certainly would not do if left to itself. In both instances, therefore, pruning may be viewed as an interference, on the part of the cultivator, with the habit of the plant, and hence unless prosecuted with intelligence may cause material injury. As a result of accumulated knowledge in the sciences of Botany and Horticulture it is now known that, should the aim of the cultivator be to produce abundance of flowers and fruits, the plant must be encouraged to form healthy branches of a particular nature. So again it is a well-ascertained fact that should the object desired be the production of leaf, everything must be done to discourage the tendency to produce flowers. The system of pruning pursued in the orchard may be said accord- ingly, to be the very opposite to that in the tea garden. And it may at once be acknowledged that, with the exception of the propagation of ornamental foliage plants and the production of new forms of certain vegetables, English horticultural experience is of compara- tively little value to the Indian tea-planter. This, it need hardly be explained, is owing, very largely, to the production of leaf forming so insignificant a part in the training given to the English gardener. It no doubt might be different with practical men who were familiar with the production of mulberry a plant grown like tea purely and simply for the supply of leaf. 176. Prevalent Conditions. These explanatory remarks have been offered as in part accounting for the diversity of opinion and practice that prevails, even in one portion of the Indian tea districts (Assam), on this all-important subject. It would be comparatively easy to understand the existence of different methods in remote coun- tries where perhaps diversities existed in climate, soil, and plant. But the state of affairs that prevails in Assam, to say the least of it, is often very perplexing. Hardly any two gardens could be said to be alike in 7 DIVERSITIES in PRUNING. Objects of Pruning. fop Fruit and Pruning for Leaf. Conf. with para. 178. Different Methods Necessary. Report of Investigations in Assam Pruning. DIVERSITIE PRUNING. Shape of Pruning, Size of Bush. Con/, with para. ZOO. Yield to Acre Governing Principle. their systems of planting out, pruning and plucking. Thus, for example, as to the initial shape of bushes aimed at : In one garden the manager prides himself in his bushes having stout erect stems, perhaps 2 feet above ground before branches are given off. In another special merit is claimed for the fact that the bushes have practically no stems, three or four main branches having been made to rise almost from the level of the ground in order to carry the leaf- bearing twigs. In a third the stem has been headed down to produce a pyramidal bush, the merit of which, we are told, is an immensely strong central axis. In still a fourth broom-like masses of erect shoots form dense clumps, produced it may be from three or four plants having been grown together or as a consequence of heavy pruning. So again, according to the system of pruning, the bushes may be kept at a very large size, say 3 to 4 feet high and from 4 to 6 or even 8 in diameter, and clipped to a perfectly flat table-like surface. According to another the bushes are small, spreading and open, in consequence of being each year pruned down to little more than 1 8 inches or 2 feet above groun d, also to their having all superfluous twigs carefully removed. According to a third the bushes are pre- served in the pyramidal condition already mentioned, so that in winter the central naked stems stand up like the masts of ships in a crowded harbour. In still a fourth the central stem is headed back and the branches and twigs in the centre yearly thinned so that the bush assumes the so-called saucer shape, being low and open in the middle but high and dense on the circumference. 177. Underlying these and such like diversities in both the initial shape desired and in the subsequent prunings, there is a fundamental bone of contention that maybe expressed thus : Distant planting with large bushes versus close planting with small bushes. But let me add that there no doubt are certain advantages of one system as compared with another, in relation to the class of plucking prescribed by the owners or agents. It would accordingly be unjustifiable were the assumption made that the diversities that exist are entirely a conse- quence of personal idiosyncrasy. The examples mentioned are, however, but a few out of the numerous diversities met with all over the vaUey of Assam. Each, it may be added, is often hotly contested as being by far the most advantageous. Should even a suggestion of hesitation to accept that Tea Pests and Blights. Pruning. view be offered, a reference is invariably made to the dividends that had been paid to the share-holders of the concern. It will be understood, therefore, that in the face of such odds it is naturally difficult to make progress in the advocacy of views that are apt to appear as purely theoretical. It is often and not unnaturally regarded as simple presumption for a person, not himself a practical planter, to assert that, better and more lasting results might be attained by a modification of systems that have been pursued with financial suc- cess close on half a century. XXVIII* Theory of Pruning. 178. One of the ablest papers on the subject of the pruning of tea bushes was written by Dr. (now Sir) George King and published in the Agri.-Horticultural Society's Journal for 1871 (Vol. III., Pt. 7). It seems desirable to give here a few passages from that paper which, it is feared, is not sufficiently well known by the planting community "Now the bearing of flowers and fruit," writes Sir George, "is the natural consummation of a plant's life, and the removal of these after they have been produced does no harm to the producing plant as an individual (on the contrary often benefits it), although the act affects its possible posterity. It is true that, in order to force it to bear unna- tural quantities of flowers and fruit, or flowers and fruit possessing unnatural qualities, the horticulturalist often exposes a plant to treat- ment which is injurious to it as an individual, and which leads to premature old age ; at the same time it is treatment, which, as regards flowers or fruit, is the most advantageous. In contrast to this is the action of the tea grower who, by the very collection of this crop, neces- sarily exposes his plants to treatment which, as regards a continua- tion of that crop, is disadvantageous." " In the cultivation of almost all kinds of fruit trees, the opera- tion of pruning holds a prominent place. The problems respectively presented to the European grower of fruit and flowers, and to the Indian cultivator of tea being different, it is only reasonable to expect that different methods of practising that operation would be advisable. The general practice of pruning as carried on by European gardeners is, however, founded, for the most part, upon a knowledge of the principles of vegetable physiology, and it is, therefore, also reasonable to suppose that Indian tea growers might have learnt a good deal 7 A THEORY PRUNING. Financial Arguments. Production of Flowers. Leaf Crop Disadvan- tageous. European Experience. Con/, with para. ITS. Report of Investigations in Assam Pruning. THEORY of PRUNING. Pruning to a fixed Height. COM/, with paras. 96, 110,208. Individual Necessities. Pruning. COM/, with para. 226. Formation of Shoots. Con/, with paras. 197-8, 828,246-7.' on the general subject of pruning from European writers on gardening even although not venturing to put their plantations under the charge of practical European gardeners with full powers to do as they might deem best. Until within a year or two ago, however, the only kind of pruning attempted in the tea gardens of the North-West Provinces, was the removal of wood actually dead, and the application on rare occasions of a hedge clipping-scissors, which delicate imple- ment used to be entrusted to a native gardener (mail) with orders to reduce by its means certain bushes to a particular height, a stick of the required length being given to him as a measure. Indiscrimi- nating treatment like this is the kind of pruning to which a few gardens in these provinces used now and then to be submitted.* Rational pruning involves consideration and selection ; and each bush ought to be treated according to its own individual condition, and not in accordance with a rule of thumb laid down for an entire field or garden. It is only certain stems and branches to which, as a rule, the knife can be applied with advantage, and these for the most part are the ones that afford the most marked examples of the natural effects of " plucking." Now, if we think of the matter for a little, the process of "plucking" will be seen to be really of the nature of pruning, and to recommend pruning as a cure for the evils of plucking, may, therefore, appear paradoxical. To explain the seeming paradox, let us consider briefly the appearances presented by a young shoot of tea before it has been deprived by the plucker of its tip with the three or four leaves or leaf-buds born thereon. Such a shoot bears on its entire length, let us say, ten leaves, and at the point where each leaf springs from the stem (i.e., at the axil) there lies a small bud. Each of these buds is capable of development into a lateral branchlet. In a branch bearing as we have supposed ten leaves, it is not probable that, were things left to their natural course, each of the ten axillary buds would become developed into a natural branchlet. When, however, ; the growing point of the shoot is re- moved, these axillary buds are stimulated by the ascending sap, and' most of them expand into lateral branchlets ; and these being in turn topped by the plucker, their axillary buds are stimulated, though in a less degree, into expansion into branchlets, and so on. The vigour * The practice is by no means unknown in Assam to the present day though the scissors is not used. [ G. Watt. ] Tea Pests and Blights";-' ^ Pruning. with which lateral branchlets follow on " plucking " or topping the leaders, diminishes regularly with each repetition of the process until after a few years of such treatment a period of nearly complete stagna- tion is reached, and the original ten-leaved shoot with which we started, presents the appearance of a tough greyish-barked and often gnarled stem, bearing at its top a dense collection of small wiry twigs, which carry a quantity of small thin tough leaves, totally unfitted for manufacture into good tea. These twigs, moreover, are of such low vitality that when topped they hardly respond by throwing out fresh lateral shoots or " flushes." This is the kind of stem of which the clumps of unpruned tea already described consist. The reason of the smallness and non-activity of the leaves upon these brush-like masses is simply that they have increased in number out of proportion to their means of nourishment. The stem, through the sap-wood layer of which their nourishment is transmitted, has not increased proportion- ally with the number of the leaves which have been forced into exist- ence by the operation of plucking ; and it is a physical impossibility that, through the layer of sap-wood in the stem, there can be trans- mitted enough sap to support many young leaves, in addition to old ones with which its top is crowned. Were such a stem left to itself, and all plucking suspended for a time, it is probable that in some cases an equilibrium would be established between the leaves and sapwood, and that the latter would again become extensive enough for the trans- mission of sap sufficient to suppotr a natural succession of young leaves, or, in other words, to " yield flushes." But the process of recovery would involve time, which to the tea-planter means money. A quicker way, therefore, of obtaining leaf must be tried, and this is found in pruning off the profitless wiry spray with which the stem is crowned, so that the sap transmitted upwards may cease to be dissipated away in the support of leaves which can never be made into tea, but which as long as they remain on the plant must hav,e their needful supply of sap ; and further, that the sap may be directed into the new shoots which the plant may be expected to throw out after pruning." " It is thus that pruning becomes the necessary sequence of plucking, if healthy young leaves fit for tea-making are sought to be continu- ously produced. The end in view should never be lost sight of when using the knife, for the mere meaningless mutilation of a plant by its application is quite as likely to be hurtful as not." THEORY of PRUNING. Number of Leaves. Low Vitality of Flush- bearing Twigs. Conf. with para. XO> P 186. Age of Primary Branches. Con/, with paras.211 f 981. 132 Eeport of Investigations in Assam Plucking. CONTINUOUS PRODUCTION of SHOOTS. Check to Growth. Less and Still Less Mature Wood. Con/, with para, 178. Flushing Power. Con/, tvith paras. 178, H06, 22S. Balance between Root and Stem Disturbed. Banjhi Buds. Con/, with paras. So, 79, 206. they are plucked. This, I am convinced, is a serious mistake. These twigs have subsequently to become the main branches to carry the flushing shoots, and they should most certainly be allowed more than one year to mature wood before being in any way interfered with. 228. It is the sudden check given by plucking, to the development of healthy wood, that is, the chief injury the plant has to battle against. When the extremity of a shoot is nipped off, the effort to mature wood that had perhaps just then commenced, is suddenly arrested, for the young leaves are the lungs and, to some extent, the mouths also of the plant. It has thus become a more imperative obligation on the plant to replace the parts removed, and in consequence return to the duty of development of wood is tardily performed. The lateral buds that may be seen nestling within the little recesses formed by the leaves at the points of their union to the twig, accord- ingly burst forth and elongate into saplings to take the place of those removed. No sooner, however, have these grown to a certain extent than they are plucked, and the, process of wood forming once more deferred. But the third set of flushings that must now come are, of necessity, borne upon less mature wood than the first. Time after time this is repeated, for perhaps 20 to 30 times a year, and each succeeding flush is, therefore, borne on less mature and still less mature wood than its predecessor. 229. This then is the state of affairs that prevails during the flush- ing season. For eight to nine months a year there may be said to exist a struggle on the part of the roots to cause the production of young shoots, in order to assimilate the continuous supply of nourishment which they are draining from the soil. By pruning the balance be- tween the condition of root and stem has been disturbed. The roots are now rendered capable of nourishing a larger number of shoots than exist. The production of shoots is, therefore, the Flushing Power of the plant determined by the pruner's knife. But it is need- less to say, this again is but the expression above ground of the state of affairs that prevails below. A sufficiency of young and vigorous roots and a liberal supply of food materials are indispensable to the res- ponse being given by the plant to the degree of pruning to which it has been subjected. 230. Banjhi Buds. It will now be seen that it would be irrational to prune beyond the ascertained flushing capabilities of the plant. Tea Pests and Blights. 133 Plucking. Planters in Assam are familiar with the condition known as banjh (barren) buds. Instead of elongating to the extent necessary to allow of plucking, the terminal bud of each little shoot seems to sulk and the leaves that have already unfolded from it have become dark-colourec and matured before they are half their natural size. The bush is then spoken of as " banjhied" Perhaps regarding few other aspects of tea plucking could a more animated controversy be aroused than as to the proper method to treat bushes in this state. Should the buds be left on the bush or plucked off ? That is the question asked on ever) hand. Now were the buds injured in any way and banjhi in conse- quence, the lateral buds on the shoot would sprout forth with as much vigour as if the terminal bud had been plucked. It accordingly follows that we must assume the inactivity of the buds is but the expression of a want of energy in the entire plant. To force it therefore, into activity by plucking the terminal buds may injure it materially. It has possibly been already overworked, the fooc supply may be insufficient or the climatic conditions unfavourable it may be suffering from some specific disease, or its stem may be so gnarled and rotten as to be unable to support the excessive growth demanded. The cause must be sought and cured. In the majority of cases manuring and a good hoeing will suffice to cause the banjhi buds to once more resume activity. Mr. David Crole is of " opinion that early in the plucking season all ' banjhi ' leaf, whether single or double, should be severely eliminated from the bushes." " I have myself tried experiments in this matter, and, to the best of my judg- ment, they answered, my expectations." After alluding to the un- certainty of experiments not " conducted under circumstances which render a careful comparison of the results over a long period (say several seasons) at the same time easy and certain, so that a reliable average may be arrived at whereupon a fair judgment of success or failure may be based," he adds, " Anyhow, I suggest the experi- ment as one well worthy of trial, and I am confident that it may be carried out without any risk of its affecting the flushing of the bush adversely." I need hardly add to the above that I regard Mr. C role's recommendation as opposed to the planter's best interests. 231. Abandoned Tea. It is a well-known fact that tea that has been abandoned for a few years, because of its having become so per- sistently banjhi (barren) that it was unprofitable, is found when again CONTINUOUS PRODUCTION SHOOTS. Treatment Should not be Plucked. Con/, with Peal's Account, Tea Planter's fade lUefium, p. 99. Plucking Re- sommended. Lbandcned 134 Report of Investigations in Assam Plucking. QUANTITY PLUCKING. Rest to Soil and Plant. Con/, with Reasons for Improvement Three Leaves and the Terminal Bud. brought under cultivation to have vastly improved. This may be explained as due to two causes : (a) The rest given to the soil through the sort of rotation afforded to it by the unrestricted growth of weeds (fallow). (3) The reparation of the defects in the bush through the rest. Being not called upon to flush it has time to mature wood to the extent necessary to sustain flushing. Moreover, the circulation of the sap becomes established by its having time to work off the obstructions caused through pruning. Both plant and soil have been brought into a healthier state. This supports in the strongest manner the argument that heavy and constant plucking weakens the bush. It causes the flushing to be made on imperfectly matured, gnarled and snagged twigs. Prun- ing becomes, therefore, an imperative necessity, the knife being made to go as far back as possible, in other words, on to the well formed red shoots of last year. XXXVIII. Plucking for Quantity or for Quality. 232. Two systems of plucking may be said to be met with in Assam. The one might be designated plucking for quantity, and the other for quality. These systems differ mainly in the age of the shoots, and, consequently, in the number of buds they bear at the time of plucking. The engraving below ( Fig. 2 ) will be found to indicate these two conditions. 233. Quantity The normal Spring shoot (A) has been allowed to elongate from the apex of last year's twig, [ (h) being the section of light pruning made last Autumn ], until it has produced eight lateral and one terminal, or, in all, nine buds. It is then plucked between (3) and (c), the portion removed containing three leaves, and the terminal bud. As a result the bud (c~) or the buds (c) and 00 or sometimes also even (e) are forced to develop. It is not desirable, however, that the bad (e) should elongate at present, and this only exceptionally happens, the usual thing being that the buds (0 and 00 are developed. At the end of the saason's plucking the next light pruning would have to be made at the point indicated by CO, so that one, two or three shoots might next Spring be expected, namely, from the buds (e), (/) and (^). It will thus be seen that the flushing shoots (c) and ( was Amoved at first plucking: the tips Jl shoots (c), (rf) and 0) at second (=ist Flush). The dark portion with leaves numbered is what will then remain Tea Pests and Blights. 43 Plucking. leaves, in addition to the phaki. In the two shoot condition (f) and (d) six leaves, therefore, remain, and in the three shoot form (<), (d) and (e), seven leaves. By another method (F), however, the two or, it may be, three flushing shoots produced, are each retained till they carry five leaves and the phaki, so that with two shoots, eight leaves remain, or with three shoots ten leaves, after plucking the first flush. 247. Leaves Retained in Quality Plucking. Similarly there are two parallel conditions in quality plucking : (G) (Fig. 5) in which the flushing shoots are retained till they have each formed four leaves and the phaki, and the other (H) in which the plucking is made when the shoots have each only three leaves and the phaki. In (G), there- fore, after the first flush has been plucked, seven leaves, and in (H) only five leaves remain. FIG. 5. RESULT OF SECOND PLUCKING IN QUALITY. The letters denote the leaves and buds of the Spring shoot as in Fig. 2 (B). Shoot (a) (c) was removed at first plucking : the tips of shoots (d) and (e) at second. The dark portion with leaves numbered is what will then remain. LEAVES on the PLANT. In G. Seven In H. only Five Leaves Remain. 144 Report of Investigations in Assam Plucking. LEAVES on the PLANT. Onttupiffrom Extra Shoots Double the Assimilating Power. . Practical Suggestion. Additional Shoots. 248. Practical Conclusions that seem Justified. These diagrams thus figuratively express very important considerations in the systems of plucking. It is not desirable, and rarely occurs, that more than two shoots are formed on (G) or (H), viz., the buds (d) and 0). The two lower buds (/) and (g) must be reserved as the stock on which the Autumn pruning has to be made. 249. It will thus be observed that in quantity plucking, there is always the possibility of three shoots (thus giving an increased outturn) and further that a larger number of leaves remain on the shoot, with quantity plucking (as in (F) its most complete form) since the shoots in each case are allowed to produce five leaves and the phaki, before being plucked. But not only are there a larger number of leaves, but the additional interspaces between the leaves open the bush up and give greater facilities to obtain light and atmosphere. 250. Compare this with the state of affairs in the most refined system of plucking for quality that to some extent prevails, viz., (H) where the shoots are plucked when they each contain three leaves and the phaki, and, consequently, at the end of the second plucking (i.e., first flush) have only five leaves left on them instead of the ten leaves of (F). 251. The system of quality plucking represented by (G) may also be revealed as infinitely superior to (H), since after the second plucking, seven leaves remain instead of five, and the greater open- ness and additional few extra days' growth, must be viewed as giving a much-needed strength to the flush-bearing frame work. Indeed it would seem that were the system shown in (F) to be pursued up to the second pluckings, and thereafter changed into quality plucking, an even better result still might be confidently looked for. I commend this suggestion for careful consideration. 252. The system of quantity plucking exhibited by (E) is, I believe, the one most generally practised. After the second plucking the shoots will be found to have left on them six leaves, if only two shoots be produced; or seven leaves, when three shoots are formed. From the point of view that it is here desired to urge, the only improvement toward the health of the plant possessed by (E) over the quality plucking (G), is in the greater age of the normal Spring shoot and the greater age of the lateral flushes before either are plucked. In point of leaf remaining on the plant this is distinctly inferior to (G), Tea Pests and Blights. 145 Plucking. though the strength given to the shoots makes it superior in other respects. 253. I have purposely tried to express the principles involved in the better systems of plucking, found by me to be practised in Assam, according to what might be called a botanical standard. I think the gradual development of the arts both of pruning and plucking, must follow some such lines and more closely than appears to have been the case in the past. I have read every book and report on tea cultivation that I have been able to discover, but in none of them will it be found that the positions of pruning and plucking have been defined according to the fixed positions of the buds. Indeed writers on these subjects have, as a rule, contented themselves by expressing their recommendations in general terms, so that it will be found none of them can be represented graphically with much hope of conveying the author's meaning. I trust I may be pardoned giving special prominence to these observations, as I cannot help feeling that something more definite must be evolved before our systems of pruning and plucking can be said to be directly adapted to the actual conditions of the plant and the requirements of tea planting. XL. Opinions of Indian Authors on Plucking. 254. Folio wing the system pursued in other chapters of this report, it may be useful if I exhibit a few passages selected from some of the better known authorities in order to exhibit the diversities of opinion and practice that prevail or have prevailed. 255. Mr. H. A. Shipp (a Cachaf planter, 1865) says, "The plucking season commences about the end of April and continues till the end of October, during which time a series of flushes occurs at intervals of twelve or fifteen days, according to the weather, and thus twelve crops of leaf may be gathered in one season." " The yield from an acre planted at 5 feet apart should be 28olb of green leaf, or 7081 of manufactured tea in the third year ; double that in the fourth, and quadruple that in the fifth year, though care and high cultivation will give even a much larger return, as both in Assam and Cachar 7 maunds or 56ott of manufactured tea have been obtained from one acre." It may be pointed out that in Assam the yield of 7 maunds an acre which Mr. Shipp thus, as it were, mentions with pride as 10 OPINIONS AUTHORS. General Terms. Definite Action Necessary. Season. Seven ds an Maunds an Acre Spoken >f with Pride Report of Investigations in Assam Plucking. OPINIONS AUTHORS. Plants Over- taxed. Three Sets of Pluekers : 1st Took Two and a Bud. 2nd Took Next Two Leaves. Lea Half Ni of Pluc a Ye H*1_f Number jckings fear. Young Shoots Plucked. Two and a Bud Will Never Pay. having been obtained, is annually doubled by many concerns, and in some instances would seem to be trebled. Instead of 1 2 pluckings a year, one hears of 30 flushings with 10, 15 and even 20 maunds an acre as the annual output. It is somewhat curious that all this has been obtained without any compensating manure to the soil, and with teas of a higher instead of an inferior quality being produced. Is there no risk, therefore, that the plants are being over- taxed and are becoming diseased in consequence ? But Mr. Shipp proceeds to describe the system of plucking pursued in his time. The coolies were divided into three sets. The first gang were designated the "Pekoe pluckers." These plucked off "the convoluted bud and its two expanded leaves." This then corre- sponded to the only plucking that is now-a-days made by gardens that go in for quality teas. Then followed the " Souchong pluckers." These plucked off the next two leaves and were followed by the third gang, or " Congou gatherers." Now, let us see what this meant. The " two and a bud " tips were nipped off and the two subsequent collec- tions stripped the shoots of their leaves but left them their buds intact. The coolies were instructed " to pluck onwards and leave about a quarter of an inch from the eye or bud for the reproduction of fresh shoots." This system was therefore about as absurd as could well be conceived. The plants were alone saved from complete destruc- tion through only half the number of pluckings being taken a year, as compared with the modern system. That circumstance no doubt allowed the shoots to grow to fully double the extent they are per- mitted to at the present day. 256. Mr. W. C. Muller (a Darjeeling planter who wrote in 1865) gives no particulars of the system then pursued except that " the young shoots alone are plucked." " By omitting to pluck the flush in time you not only lessen the number and rapidity of your flushes, but in order that the tree may flush again, you are compelled to pluck leaves which have grown so old and stiff that they are rolled with difficulty and break during this operation." 257. Colonel Money's chapter on Plucking is so involved and con- tradictory that nothing would be gained by discussing it in detail. Alluding apparently to the system of plucking separately the Pekoe "two leaf and a bud," mentioned by Shipp, he says, " It has been attempted again and again to do it, partly to the extent of taking the Tea Pests and Blights. Plucking. Pekoe leaves a, b and c* separate from the others (for the manufac- ture best suited to these upper leaves is not suited to the lower), but it has been as often abandoned, and I doubt if it is now practised anywhere. I am sure it will never pay." Fortunately for tea-plant- ing Colonel Money's theories did not gain any very great hold on the minds of practical men and consequently the kind of plucking that, in the fourth edition of his work (published 1883), which he said would never pay, is that alone followed by perhaps more than three-fourths of the tea planters of India. To conclude this reference to Colonel Money and his system of plucking tea, it will suffice to give the foil owing as fairly characteristic of the spirit of the chapter on this all-important subject, " Shortly, the principle I advocate is to prune severely, so that the plant in self-defence must throw out many new shoots; to be sparing and tender with these until the violence done to the tree is in a measure, but not quite repaired ; then till Septem- ber, to pick so much that the wants of the plant in foliage are never quite attained ; and after September to take all you can get. " Under such a treatment it was fortunate some consideration was given to the growth of shoots before the merciless plucking began. 258. Mr. J. F. W. Watson published in 1872 an account of tea- plucking. It is a very elaborate one and, to some extent, might be called a modification of that already given by Mr. Shipp. The tip, with its terminal bud and first leaf only, was to be taken off, and also the top two-thirds of the next leaf, but not its bud. This would be expressed by saying the first plucking was made between (3) and (c) Fig. 2 B, instead of between (c) and (rf). Later on, when the wood of the shoots was supposed to have been formed, "two-and-a- bud " was taken and the two or three leaves below. This system had the advantage of giving an extra bud, thus allowing of one more flushing shoot, but the collection later on of the 3rd, 4th and $th leaf, counting from the apex of the shoot downwards, must have weakened boih the bush and the quality of tea. If quantity be desired, " three- and-a-bud " uniformly pursued would be both superior and simpler. Some of Mr. Watson's general observations on the importance of giving the bush some time to develop, in the early months of the * This reference is to his plate on page 104 (a) the bud, (b) first leaf and (c) the second leaf of " two and a bud " modern pluckings. (as in Fig. 2 B. above). 10 A OPINIONS AUTHORS. Prevent Plant from Attaining its Wants in Foliage. First Plucking One and Bud with Portion of Third Leaf. Subsequently Two and a Bud. Portions of 3rd, 4th and 5th Leaves Stripped. Report of Investigations in Assam Plucking. OPINIONS of AUTHORS. Bad Plucking Impairs Vitality. Care Needed with Young Shoots. not be Plucked in Spring. First Flush Should be Allowed to Grow. season, are valuable. On plucking he says depends " the yield of leaf (and therefore the outturn of tea), and the condition and health of the bush very greatly depend, to a greater degree than those not well acquainted with the cultivation of the tea would probably believe. Bad plucking will most undoubtedly tend to impair the vitality of the plant and will diminish its yield, while careful pluck- ing conducted on sound principles will have the precisely opposite effects. " " A good deal depends, in commencement, as to how the bushes have been pruned. If they have been cut down very low then the utmost care and circumspection will be needed in dealing with the new shoots, for these must be looked on as the nuclei of the future tree ; for the bush as left by the pruner, it will be obvious, is hardly worthy of being called a tree ; and was to grow to one, and if, therefore, care be not taken with the coming shoots, there will be no tree at all, and the pruned bush will just remain what it is. With bushes that have required little pruning, and are of good average size with no lack of young wood, the same degree of cautiousness is scarcely needed ; or neglect, at least, will not produce disastrous effects, as in the other case." " Assuming that a bush has been from necessity pruned down to 18 inches in the close weather, leaf in the Spring month should be no consideration what- ever, nor should ever be plucked till a good growth of young wood has been fully secured. No shoot should be touched if less than 8 inches long. " 259. Mr. T. G. Stoker (a Cachar planter, 1874) has some useful and practical hints. His little work might almost be described as having been written in the transitionary period of old shoots subse- quently deprived of their terminal bud and of the five or six leaves below and the modern school where " two and a bud " or " three and a bud " is uniformly taken. He says " I would suggest that the first flush should always be allowed to grow out, and that it should not be tipped until having again gone on and made three or four further leaves. I would never endeavour to increase the yield by plucking coarser leaf, but I would gradually do so by taking the flushes at a younger stage." " By letting the plants start unchecked, this great advantage is also gained, that the shoots not having been checked at first, they do not break from their lower axils, and fine clean wood is secured for next year's pruning." Tea Pests and Blights. 149 Plucking. 260. Mr. 8. Baildon (Tea in Assam) remarks that, " Plucking has to be watched most carefully, for if carelessly done, the garden will b thrown back to a very serious extent. Sometimes, instead of plucking in the way which they know to be correct, the women strip the leaves, by putting their hand below the lowest leaf to be plucked and then drawing it roughly upward. The risk is, that women will pluck a shoot too low down, and bring in coarse hard leaf which is not wanted, as it takes a long time to wither, and the good leaf becomes over-withered whilst waiting for the coarser, which acts as does China in breaking or bruising the fine leaf and spoiling the general appearance." Mr. Baildon then proceeds to describe the method of nipping off " two-and-a-bud " along with the upper half of the third leaf. It may be said that the system of tearing off a portion of a third leaf was and indeed is (for, to some extent, it is still practised) a survival of the more barbarous system of stripping off two or three leaves below " the two and a bud " plucking. Fortunately the habit of tearing off even part of the third leaf is rapidly giving place to the more rational and definite methods of quantity plucking which I have already described. 261. Mixed Leaf .Mr- Baildon concludes his chapter on Pluck- ing with a most instructive paragraph on the difficulty of both plucking and manufacturing leaf brought in from a mixed garden of Assam indigenous, hybrid and China bushes. " Assam and China bushes growing together," he says, " give more trouble to the planter than a novice would imagine. He must either take the China flush when that is ready, and sacrifice the superior hybrid and Assam leaf, or allow the China to grow until the other is ready, and then have uneven leaf brought in for manufacture, and this is a great nuisance. With leaf which would of itself make fine, good-looking tea, there is mixed up a lot of coarse, hard China leaf, and when rolled together the latter snaps, mixes with the good leaf, breaks or bruises it, and the manufactured tea, instead of presenting a good appearance for whole leaf, looks more like broken tea, with a lot of small, hard, flat pieces of China leaf standing out in bold relief, spoiling the appearance of the whole." 262. NoteaonTeainDarjeeling-by a planter commences the chapter on Plucking by the remark that, " Of course everything OPINIONS of AUTHORS. Difficulty In Withering. Two and a Bud with Upper Half ofThird. Difficulty in Working Gardens or Mixed Jats. Con/. uAtH paras* 72, 76, 79, 89. 150 Report of Investigations in Assam Plucking. OPINIONS AUTHORS. Special Treatment fop Sides of Bushes. Number of Buds Left Dependent on Vigour of Shoot. Plucking Portion of 3rd Leaf Does iasten :hing. Hard versus Light ing at eginning of Sea Lig Plucki Beginn Number of Flushes. Con/, tvith paras. 238, depends on what sort of pruning has been done. And what sort of tea is wanted." It then continues, " In any case directly the bushes begin to shoot have a gang of coolies on taking out all the open leaf which shows. Put on a good many coolies, as if once the leaf is allowed to get ahead, it will be almost im- possible to catch it up again." " Two leaves and a bud ought to be picked, but sides of bushes on no account touched until they get to level of rest of the bush. In the second flush again have the best people going round taking off longer shoots and leaving an extra two leaves." In the third flush leave one leaf again making five in all (if the growth is stunted), if it has run up well four leaves will be suffi- cient." " Thin out bushes as much as you can, and on no account leave too much growth from any particular flush, as the longer the growth you leave, so much longer will it take to harden up ; and if the weather is cold, the next flush may be delayed for weeks." " Many planters advocate picking half the third or Pekoe-Souchong leaf, and say the flush comes on sharper if this is done. It may be so in the plains, but it is not the case up here." 263. Mr. M. Kelway Bamber, {Chemistry and Agriculture of Tea, 1893}, v ery truly remarks that, " The ideas on plucking are many and varied, and much has been written on the subject since the com- mencement of tea-planting in India. Some have advocated one method, and others an almost entirely opposite one, both giving valid reasons to justify their processes. The age at which plants are first regularly plucked also varies in different districts, but usually at three years ; a light tipping being sometimes given at two years to assist in the formation of the bush. There are some who recommend hard plucking at the commencement of the season, and others who say pluck lightly at first, and gradually pluck harder as the season pro- gresses. The number of flushes during the season averages 1 1 to 12,* and after a light pruning, the first is allowed to grow about six leaves before plucking commences, when the top two or three are taken, the second flush to grow about five leaves, and so on." I refrain from detailed comment on the above passage which may * In a further passage Mr, Bamber mentions that, according to Bruce, "the indigenous bushes of Assam only yield four flushes." Hence " It will be noticed that the rate of flushing has largely increased since tea- S 'anting was first commenced." I have already stated that in Assam e flushings average from 20 to 30. G. W. Tea Pests and Blights. Plucking. possibly have been written as expressing an average of all conditions throughout the Indian tea districts. It could hardly be said to be applicable to Assam. But Mr. Bamber's remarks that follow are most instructive and deserve to be carefully perused (pp. 208-211 of his work) more especially the passages regarding the higher total extract and more tannin in young as compared to old leaves. " As tannin is the chief source of the strength of tea, the advisability of plucking young leaf is apparent, when thick liquoring teas are required." 264. Mr. David Crole (A Text-Book of Tea Planting and Manu- facture, /3Eb of phosphoric acid, i^itt) of lime, and 2olb of nitrogen per acre. " In attempting to return to the soil in the form of manure all the fertilising constituents abstracted by the plant it must be borne in mind that it is impossible to calculate the composition of a manure so as to represent the exact proportion of plant food necessary. The ash of the tea leaves, for instance, does not give an absolute indication of the loss, as the prunings with a larger percentage of lime have to be taken into account, the available nitrogen and salts and their combi- nations must be known, and it should be remembered that the several parts of a manure are not absorbed by the roots with equal velocity. 290. "A Manure for Tea. Considering that there are four elements eminently necessary for the tea plant, the following mineral mixture would supply a very suitable manure. The potash salts would first be assimilated because of their ready solubility, while the phosphates would require the action of the soil and carbonic acid to make them sufficiently soluble : Mineral phosphate } L - me rf 3'9 2 Saltpetre (95 per cent.) Ashes (of wood or plants) f Potash * ( Nitrogen (in nitrate) C Potash 20 < Phosphoric acid (Lime. Materials Removed from the Soil. Conf. with. para. V7O. A Manure for Tea. 1 66 Report of Investigations in Assam Tea Fertilisers. " A manure of this description could readily be prepared in India. A mineral phosphate of the above composition is afforded by the deposits of nodules near Trichinopoly. If mineral phosphate is not procurable in Northern India, bone-dust, an article which would supply additional nitrogen or ammonia, might be substituted. If more nitrogen is required, the ashes might be replaced by one of the many oil-cakes obtainable at a cheap rate wherever oil-seeds are cultivated and pressed. XLV. Green Manuring. 291. "An application of green leaves or herbaceous plants, to regenerate the soil has been resorted to from time immemorial both in wet and dry cultivation. There can be no doubt that it is one of the most economical manures and a very convenient source of nitrogen. But for the leaves to be of advantage to the land there should be a deficiency in organic matter in the soil, and lime, potash and phosphoric acid must be present, as the mineral matter in green manure is not rendered available for use until decomposition is far advanced. It is usually applied by allowing a herbaceous crop to grow nearly to maturity, and then ploughing or hoeing it into the earth. At other times certain plants which are empirically known to improve cultivation are brought from a distance and worked into the soil. The leaves that fall from the shade trees planted in an estate, contribute no doubt to the more valuable constituents of the soil, although their action may vary according to their chemical composition and the time of year when they are shed. Green manure renders the soil porous, and is more especially suited for exhausted sandy loams. 292. The following information concerning materials of this description which have been used either experimentally by European planters or for ages by the ryots, will serve as a guide to their value. " The Acacia dealbata, or Yellow Wattle, is a leguminous tree introduced on the Nilgiris, the tops of which have been tried as a source of fertility to coffee and tea soils. It is richer in nitrogen than cattle manure, and is very abundant near tea estates. Tephrosia purpurea, a leguminous shrub related to the indigo, is used by native cultivators in Tinnevelly, who buy it by the cart load, and consider the leafy branches of great value for their crops. Erythrina lithos- perma is the 'Dadap' of Java. It has been introduced into some Tea Pests and Blights. 167 Tea Fertilisers. (D. Hooper.) estates as a shade and has been recommended for its manurial pro- perties. The roots are provided with nodules similar to those of other nitrogen gatherers of this order, and the fallen leaves are said to benefit the soil, and ultimately the plants, growing near the trees. Desmodium gangeticura, a leguminous herb, has also been tried as a green manure in Southern India. The large leaves known in Tamil as watta-gunie (Macaranga Roxburghii) have been used for cen- turies by the natives all over Mysore and Travancore for improving their rice crops. The tree is found near tea estates, and a sample of the fallen leaves was sent to me for valuation. The watta-gunie belongs to the natural order EUPHORBIACEJE. The above four plants were supplied by Mr. E. M. Ewart, of Shencotta, who advocates green manuring very extensively. The table below gives the analyses of these plants as also of Adhatoda Vasica. The remarkable manurial value of that plant is appreciated by the agri- culturists of Northern India. 293. " The following analyses show the uniformity of the nitrogen in the first three leguminous plants and the variation in the amount and constitution of the mineral matter. The results are calculated on the absolutely dry plants : Acacia Tephrosia Erythrina Des- Maca- Adha- dealbata. purpurea, lithos- medium ranga toda perma. gangeticura. Roxburghii. Vasica. Albuminoids . 17-64 17-51 17'45 20-16 15-23 23-43 Fat . . 3-80 7-03 2'6o 5-66 9-65 5-82 N.- free extract 49*18 40-36 2931 14-50 23-41 18-87 Crude fibre . 25-55 28-39 43 35 49'38 44'94 3'28 Ash . . 3:83 671 7-29 10-30 6-77 21-60 GREEN MANURING. Desmodium. Macaranga. Adhatoda. Con/, with Hand-Book recently published. Analyses. Value of weeds to the Soil. Conf. with paras. 95, 99, 1O9-H8. loo- loo 1 loo- ioo' loo- loo- Nitrogen . 2'8o 278 2-77 3-20 2*41 372 In ioo parts of ash. Potash . . 13-84 23-23 35-14 1864 I4' 20-11 Lime . . 26-32 18-63 9-14 20-68 I4'22 Phosphoric acid 5-13 5-89 8-41 3-40 6*31 Silica . . 6-59 2-23 2-44 13-59 24-28 1-86 294. " It has been noticed in California that trees give a decreased production of fruit when the orchards are constantly weeded and the soil deteriorates physically notwithstanding the application of manures. Mr. E. Hilgard in 1896 used the square pod pea (Lotus Tetra- gonolobus), as a green manure to supply the nitrogen to the soil. i68 Report of Investigations in Assam Tea Fertilisers. The plant was most suitable ; it yielded 24-26 tons per acre. The nitrogen percentage is less than that of lucerne or clover, but the nitrogen of the produce of an acre is much larger. 295. " In Assam the manuring of tea is usually practised in the cold weather. Some good results have, however, been obtained with manure applied later, and some planters have advocated June as the best month when the land is moist with the early showers. Mp. T. G. Stoker, of Cachar, recommends weed and grass mulching as a capital method for improving the surface soil. For the sides of fee- lahs and exposed western slopes mulching is perhaps the best plan that can be adopted. It has been found that 800 maunds of a mixture of green weeds with cowdung hoed into an acre during the rains has given excellent growth and has doubled the yield of tea. XL VI. -Nitrification. 296. " The nitrogen in the organic matter or humus of the soil is for the most part in an insoluble condition and not available for the food of the plant. The oxygen of the air acts upon the vegetable albumen and produces ammonia the odour of which is always notice- able in stables and in pits where vegetables are allowed to rot. The ammonia combining with certain acids forms soluble and neutral salts which are readily absorbed by the roots. The whole of the ammonia is not disposed of in this manner ; a portion is attacked by a minute organism or ferment which changes it into nitrous acid, and another organism acting upon the nitrous acid changes it into nitric acid. This process of converting ammonia into nitric acid is a process of oxidation and is carried out in two stages by two distinct forms of bacteria which are recognisable under the microscope. The little organisms are termed nitrifying bacteria and the whole process is known as nitrification. Nitrification is a most important part of natural fertilisation and is more or less actively going on in all soils. The effects of nitrification are seen in the saltpetre deposits near aban- doned villages in India, and in the dry regions of Chili and Peru such vast accumulations of sodium nitrate are found that thousands of tons are exported annually to the United Kingdom and the continent. XLVIIThe Fixation of Nitrogen by Plants. 297. " The method of assimilating nitrogen from the atmosphere Tea Pests and Blights. 169 Tea Fertilisers. (D. Hooper.) by means of root tubercles should be clearly distinguished from the process of nitrification which has just been described. The reader will find much useful information on this subject in an issue of The Agri- cultural Ledger No. 7 of 1894. The present remarks are indeed intended to amplify that paper in one or two directions, more espe- cially in giving an explanation of the well-known properties of the sau tree (Albizzia stipulata). The question whether free nitrogen can be taken up by plants has been a source of discussion among scientific agriculturists for many years. It was accepted, as a rule, that this element could not be used by the plant except in combination in the form of humus, manures, and rain-water. Messrs. Lawes and Gilbert, however, in the course of their experiments on crops, found ! that leguminous plants, such as vetches, beans and peas, contained more ntirogen than could be accounted for by the ammonia and nitric acid supplied in manures and rain-water. In addition to this fact it should be mentioned that it has been known for hundreds of years that the fertility of the soil could be improved by the growth of leguminous crops in rotation with other crops. 298. "In 1886 Hellriegel and Wilforth, after working for three years on the subject of direct nitrogen assimilation by plants, dis- covered that many of the PAPILIONACE.E (a sub-order of the LEGUMI- NOSJE), obtained a large proportion of their nitrogen from the atmos- phere. The excess of nitrogen was due to certain micro-organisms that flourished in and around the roots of these plants which as- similated the gas and rendered it available for the plant. In the absence of these organisms the fixation of free atmospheric nitrogen did not take place. Having found that nitrogen was absorbed from the air by these organisms, the German chemists deter- mined to test whether the nodules or tubercles on the roots were in any way connected with the nutrition of the plants. These tubero- sities never appear in sterile soil, and are always associated with luxuriant growth. On cutting them open and examining them micros- copically, they are seen to contain amongst their cells a ramifying growth which in time gives rise to a number of small cells having much the appearance of bacteria, and called by some investigators Bacterium radicicola. The nodules contain a large quantity of nitrogen, but the quantity appears to vary according to the develop- ment of the plant upon which they grow. Stoklasa in 1895 examined FIXATION of NITROGEN. Sau Tree. COM/, with paras. 11, 86, 110, 3O2-3, 311. Hellriegel Wilforth's Discovery. Report of Investigations in Assam Tea Fertilisers. the roots and nodules of the yellow lupin and found the following percentage of nitrogen present : In Roots. In Nodules. Flowering period . . . 1*64 5-22 Fruiting period . . . 1*84 2'6i jpomplete ripeness . . . 1-42 171 299. " The manner in which the nitrogen is used by leguminous plants is not perfectly understood, but it is generally supposed that the bacteria present in the tubercles feed upon the nitrogen, and the foster plant feeds upon the bacteria. Others maintain that the bacteria give rise to degenerate forms called bacteroids which are the indispensable factors in nourishing the plant. Prazmowski has summarised the conclusions arrived at thus : 1. The root nodules are symbiotic* formations, which derive benefit from the plants by obtaining nourishment from them, and are thus enabled to propagate themselves, and on the death of the plant to return in greatly increased numbers to the soil. 2. The symbiosis is of use to the plant by enabling it, under the influence of the bacteria, to feed on atmospheric elemen- tary nitrogen. 3. Only plants provided with nodules can acquire nitrogen from the free nitrogen of the air. 4. The recovery of the infected plant and the emptying of the oldest nodules are coincident. 5. The absorption of the bacteroids is the means by which the plants obtain atmospheric nitrogen. 6. It is probable that the bacteria are built up of starch and elementary nitrogen. 7. In the absence of other sources, the nodule-bacteria are able to assimilate free nitrogen, although to a much less extent than when in symbiosis with the plant. 300. " It was at first supposed that nodule-bearing plants were confined to the PAPILIONACKJE, and that no other family had the power of absorbing nitrogen from the air. Recent experiments, however, * A term that may be defined as the living together of dissimilar organisms. G. W. Tea Pests and Blights. 171 Tea Fertilisers. (D. Hooper.) have shown that that phenomenon is not the peculiar property of the pulse-bearing plants. The ALGJ:, for instance, have the power of fixing free nitrogen, and it is impossible to say at present to what extent these lower organised plants are concerned in supplying nitrogen to the higher forms of vegetation. 301. " Nobbe has found that a flowering tree, the Elaeagnus hor- tensis, far removed from the LEGUMINOSJE, has tubercles on its roots and is able to fix free nitrogen. Hiltner in 1895 made the interesting discovery that the roots of the alder (Alnus glutinosa) if provided with nodules, utilise nitrogen in a similar manner as the PAPILIONACE.E. It was noticed that the organisms that produce nodules in the alder root act as a parasite until the nodule is fully developed, after which the plant benefits. A comparison between analyses of the alder nodules and those of the lupin reveal a great difference in the amount of com- bined nitrogen present in the form of proteids. Roots of Alder . 5-4 per cent, of protein. Nodules . 8-3 Roots of Lupin * 5-2 Nodules . 31-6 "The alder appears to a disadvantage when compared with the lupin, but the appearance of nodules on its roots is an interesting observation. In this connection attention may be drawn to the fact that the alder leaves contain more nitrogen (3'6i per cent.) than the leaves of many of the common forest trees of Europe as shown by their examination by Professor Emmering about 12 years ago. 302. " Regarding the plants outside the PAPILIONACE.E which deve- lop root nodules, refeience must be made to the leguminous shade trees used in tea plantations, a subject which brings us to a practical consideration of the supply of nitrogen to the tea plant. " Several years ago Colonel Hannay (in Dibrugarh, Assam) called attention to the value of the sau tree and gave it the name of the tea fertilising tree. The sau tree is Albizzia stipulata of botanists, and belongs to the sub-order MIMOSE^E of the LEGUMINOS^:. To Mr. J. Buckingham belongs the honour of having prominently drawn attention to the value of the sau tree. Several experiments were made by him which went to prove that sau possessed peculiar properties in bringing round exhausted soils and causing the bushes to The Sau Tree in Tea Gardens. 172 Report of Investigations in Assam Tea Fertilisers. flush vigorously, while imparting a vitality of which old tea was defi- cient. On the 2$rd October 1884, Mr. Buckingham published, for the benefit of the Indian Tea Association, a little pamphlet on this subject which gave his own experience and that of several planters regarding the sau tree. Shade is not usually the cause of an increase of yield,, and is in fact condemned by the generality of planters, as it tends to make the bush throw out long stalky shoots and thus to produce poor and woody flushes ; such, however, can hardly be said to be the case when sau is employed. The tea bushes under that tree have been reported by those who believe in it to yield a considerably higher amount in a given area than in any other part of the garden, under similar conditions of soil and age of bush. It has been observed that tea grown under sau enjoys a considerable immunity from blights and pests, while the surrounding trees are suffering badly. " The action of the sau was attributed by some to the beneficial shade which it casts over the plants ; others considered that it was the manure furnished by the dead leaves ; a few thought that the advantage of interplanting the trees was the fact that the roots went to a greater depth than the tea roots, and drained the superabundant moisture from the surface soil, while, on the other hand, they brought up from the sub-soil food material for the tea plants. Mr. Buckingham remarks, ' I do not wish to contend that sau is capable of improving tea plants where the soil contains elements which in some instances nature has abundantly supplied for the support of the bush, but I do assert that the vitality of the tea bush is limited probably in a great measure depending on the character of the soil, and unless we restore some of those essential parts we are yearly, I may say weekly, abstracting, the tea-planter in a few more years may be surrounded by tea which the very best cultivation and the most scientific pnining can never bring round.' 303. " The immediate benefit which Albizzia confers upon the soil and the tea plants where it grows is not due to some chemical ingre- dient imparted to the soil, as was once supposed, but to the presence of tubercles which are attached to the roots. The discovery of these tubercular bodies on the roots of the sau tree was made by DP. Watt during his tour in Assam in 1895. Dr. Watt not only noticed the prevalence of the nodules but, by examination under the microscope, he was able to detect the bacteria in the cells of these structures. Tea Pests and Blights. 173 Tea Fertilisers. (D. Hooper.') This then is another instance that the fixation of nitrogen by means of nodule-bacteria is not confined solely to plants of the PAPILIONACE.E. Since this discovery Dr. Watt has found that the Sensitive Plant (Mimosa pudica), the bab&l tree (Acacia arabica), and many other species of the MIMOSEJE possess nodules, but that so far none of the C^SALPINIEJE have been found to do so. 304. " The comparative absence of blights in the vicinity of trees of this order is a very important point in connection with successful tea cultivation. The action of nitrogen in the soil may not interest some planters, but when they see the pests of their gardens kept off by certain trees, which serve a double purpose of fertilising the sur- rounding land, the subject becomes one of no mean importance. 305. " In Dr. Watt's diary (kept during his tour in Assam), refer- ence is made to another legume-bearing bush which may be here mentioned. ' I was taken,' he writes, ' to a discontinued portion of the garden where I found a species of Dalbergia (medeloa). Around these trees, tea was seen in large healthy clumps of dark green bushes, while between these clumps the plants that formerly existed had all died, or were small and sickly. By my direction certain seedlings of the Dalbergia were dug up, and on subsequent microscopic examination these were discovered to contain a Bacterium in their root tubercles. It was, moreover, recorded as remarkable that in the deserted garden no blights could be seen except two or three bushes with thread blight, one in a particularly vigourous clump right under a Dalbergia. I next inspected the hilly portions of the estate where the tea yields so little that the terraces are only hoed once a year. The bushes were mostly China or poor hybrid and in bad condition. Blights were prevalent except under and around a semi-scandent Dalbergia where they were large and healthy-looking. It thus seemed a matter that placed beyond doubt that leguminous trees were beneficial to the tea and, to a certain extent, gave immunity from disease.' 306. " In another district DP. Watt had occasion to visit a garden where medeloa (Dalbergia assamica) trees had formerly been planted. ' The tea was one of the finest bits in the garden, large, well- formed plants of a deep green colour, flushing freely. As the medeloa belongs to the PAPILIONACE.& it had enriched the soil and the tea was reaping the benefit for years after the medeloa bushes had been felled.' FIXATION NITROGEN. Nodules In the Mtmosese. Advantages Derived from Dalbergia. 174 Report of Investigations in Assam Tea Fertilisers. XLVIII.-SoU Inoculation. 307. " The other method of bringing nitrogen to the crop besides that of directly applying nitrogenous manures is by inoculation of the soil with bacteria. In the process of assimilating nitrogen by the agency of nodules on the roots of leguminous and other plants, the nodules yield up to the soil myriads of bacteria. These bacteria live normally in the soil, but are especially abundant in soils where leguminous crops have grown ; they fix upon the roots of certain plants, absorb nitrogen for their benefit and are after certain changes consumed by the plant. The absence of nitrogen-bearing bacteria from the soil gives rise to ' nitrogen hunger ' in the plants and this is known by the unhealthy appearance, slow growth and the lighter colour of the leaves. The presence (of these bacteria under normal conditions increases the vigour and development of the plant, im- proves the flower and fruit production, and prolongs the vegetating period. The experiments of Nobbe and ttiltner in 1896 would seem to show that inoculation with nodule-bacteria is effective in plants of a similar kind. Thus in the LEGUMINOSA the bacteria of the pea (Pisum) was not used up by the vetch ( Vicia) , the bacteria from the kidney- bean (Phaseolus) nodules were not rendered available for the Robinla, and the inoculation of lucerne (Medicago sativa) with clover-bacteria had scarcely any effect. The bacteria used for inocula- tion, if a successful result is to be expected, must correspond with the plant, and the best results are obtained by using the organisms of a particular plant, as Robinia for the inoculation of that species. The soil may be inoculated in two ways : ist, by broadcasting some hundredweights of earth taken from land that has yielded a good leguminous crop. 2nd, by watering the field with water which has been in contact with earth from land which has yielded a good leguminous crop. (For further information on soil inoculation, see an article on " Green Manuring " in Journal of the Board of Agri* culture for June 18^7.) 308. "A preparation in the form of a gelatine cultivation has recently been made in Germany which under the name of nitragin is said to supply the peculiar bacteria for leguminous crops. The inoculation of the soil by this article is very simple. The liquified medium is diluted with sufficient water to moisten the seeds, or it is mixed with dry earth which is scattered over the field. As the pre- Tea Pests and Blights. 75 Tea Fertilisers. (D. Hooper.') paration has to be kept in the dark and must not be heated above the temperature of the human body, it is not likely to be used with much success in India. 309. " Dr. Watt has made the practical suggestion, however, that instead of the use of highly cultivated media and soil infusions, the soil itself in which a leguminous crop has been grown should be dis- tributed broadcast over plantations where nitrogen hunger is observed. The proposal is as follows ' 500 acres should be divided into five or ten plots each in rotation to be sown with matti-kalai (Phaseolus aconitifolius) or other leguminous crop. After the legume is grown and ripened hoe in the green stem and leave the plot of land till com- plete decomposition has taken place. The soil will then be highly charged with bacteria and by scattering it in handfuls all over the estate the soil will be inoculated with nitrogen-forming organisms.' 310. "The above method is in keeping with the theory that, when a papilionaceous crop is grown mixed with a non-papilionaceous crop, the latter will possibly derive benefit from the nitrogen fixed by. the former. In the case of cotton growing along with indigo or guinea grass with lucerne, it is likely that the non-leguminous plants receive benefit from their neighbours. It is hardly necessary to point out tubercles on the roots of plants as a means of distinguishing those that contain a large quantity of nitrogen from those that yield a small amount. Tea has never been observed to grow nodular formations, but it has been proved that the bushes are all the better for being reared near nitrogen formers. "There are many points to be examined into in connection with the manuring of tea soils, in procuring the best fertilisers, in culti- vating the best crops for green manuring, and in selecting the most suitable leguminous trees for avenues. The action of external agents in producing the tannin, or the alkaloid, or the flavour in the prepared tea-leaf is a domain upon the threshold of which science has scarcely entered. Careful experiment and patient and accurate observation are required to carry on the discoveries of others and to bring the cultivation of tea to a more satisfactory issue." XLIX. Concluding Remarks on Tea Fertilisers. 311. I have allowed Mr. Hooper's contribution to this report to appear in the form written by himself and have only exercised a slight editorial supervision. I have on several occasions suggested iOIL CULA- ION. Practical Application. Sfatti-kalai. Conf. with par ait. //;, 312. Benefits of Nitrogen Inoculation. Tannin in Tea. Conf. with paras. X63, 311. Report of Investigations in Assam Tea Fertilisers. FERTILISERS Manuring a Pressing Necessity. Absence of Rotatio of Croi Value of Sau Trees. Shade Temporary. that the study of tea manures should assume two forms, (a) those calculated to remove defects in the soil and thereby improve the health of the plant ; () those having a direct bearing on the im- provement of the quality of the tea. Whether chemical research has advanced far enough to allow of the second consideration assuming a practical form, may be open to doubt. That manuring tea has become a pressing necessity, however, there can be little room for doubt. But the first and most urgent demand is to meet in some way the defect of there being no rotation of crops in the tea planta- tion. The value of certain leguminous plants, in the supply of ni- trogen to the soil, cannot be too loudly proclaimed. Mr. Bamber in two or three isolated passages alludes to this subject, but it is so important and so obvious that I was surprised, on first reading his valuable work on the Chemistry and Agriculture of Tea, to find that he did not devote a special chapter to this subject. He apparently never thought of examining the roots of the sau, and thus could not have had any very definite conception of its aiding in the direction here more especially indicated. But it is not so much the presence of large sau trees in an estate that is beneficial as the fact that the thin pods of that tree are blown in the wind and the seed thus sown all over the estate. These spring up as self-sown seedlings only to be hoed in as green manure. They have lived long enough in the soil even then, however, to have become powerful agents in the supply of nitrogen. I am thus not by any means sure that we have even yet found a better plant than Mr. Buckingham'sfavourite the sau. But I should strongly recommend that it should be treated as a green manure. The roadsides of all tea gardens might with advantage be planted with sau trees. It is, as I have already mentioned, com- monly found in association with the truly wild tea plant. It has never been shown to be in any way injurious to the tea, and its shade is only temporary. A crop of seed might annually be obtained from the avenues and sown broadcast in selected plots of tea. When two feet or so high the crop could be hoed in as green manure. It would not, however, be necessary, nor practicable, that the whole of an estate should bear a crop of sau at one and the same time. Were each portion of the garden in rotation, every fifth or sixth year so treated, I have little doubt in affirming that a vast improvement would be brought about. Tea Pests and Blights. 177 Tea Fertilisers. 312. I have no faith in soil inoculation, so far as tea planting is concerned. But there are many more plants rich in root-warts besides the sou. The climbing and bushy species Dalbergia volubilis, D. assamica and D. stipulacea (medelod) are perhaps quite as good. Then again the sensitive plant has perhaps more root nodules than any other plant in Assam. Its thorns render it, however, impracticable except to sow on old nurseries and Assami village sterile plots. A crop of the sensitive plant would rapidly improve any land that there may be no occasion for coolies to walk over for some short time. The jungles of Assam contain many common species of leguminous plants such as Crotalaria striata, Des- modium polycarpum, Tephrosia Candida and Uraria crinita. These would grow as weeds on the tea land if sown and left alone for a month or two. The coolies treading on them while collecting the tea, would not materially hurt them, as they are hardy plants, and the Desmodium mentioned is procumbent. Many planters have already acted on the suggestion to grow mutti-kalai (Phaseolus aconitifo- lius), the cultivation of which is fully understood by the coolies; that plant should, I think, prove of great value. One company has imported from England a supply of lupin seeds and raised a crop as a nitrogen giving green manure. I have not heard the result, but the yellow lupin (Lupinus luteus) has been long recognised in England and Germany as one of the best plants for this purpose. 313. But I would here urge the suggestion already offered (para- graph 165) that strips of land should be left through every estate for ventilation purposes. Even if pipe drains be found impracticable or too expensive, these strips of land would be simply invaluable for the cultivation of nitrogen-giving plants, and an exchange of soil from these strips with the intervening plots of tea would, in my opinion, be perhaps the most economic and practicable method of securing the much-needed renewal of soil fertility. But it is enough for me to suggest the imperative necessity for this subject being taken into serious consideration. Difficulties are no doubt likely to be experi- enced, both in discovering the best plant and most convenient method of cultivation, but these and all such objections will instantly dis- appear when the subject is approached in the spirit of an earnest desire to secure the advantages indicated. >ERS. Strips of Land fop Leguminous Crops. 178 Report of Investigations in Assam The Tea Pests and Blights. Constitu- tional Diseases. Conf. with paras. 26, 30, 45, 51, 92, 106, 166 186, 197, 318, 320. Predisposi- tion to Pests. Conf. with paras. SO, 47, 92, 226, 282, 32O. Scientific Report. Conf. with paras. 2, 34 63,92. Experiment Indispen- sable. Conf. with paras. 23, CHAPTER X. THE TEA PESTS AND BLIGHTS. L. Introductory Observation. 314. As a matter of convenience I have accepted the word " Pest" to denote Insect and other Animal.Enemies, and the word "Blight " to refer to Fungal and other vegetable Parasites of the Tea Plant. While convenient the restrictions indicated for these words are of course open to criticism. 315. In the preceding chapters I have endeavoured to represent certain aspects of the cultivation of the plant that seem to me to call for more careful investigation, with a view to reforms. To my mind there exists sufficient presumptive evidence to justify the opinion that certain misapprehensions and defective methods of procedure have originated constitutional weaknesses that may be said to constantly predispose the plant to actual disease. In other words to render the depredations of its enemies and parasites more alarming than they might be otherwise. I have, therefore, advocated that such reforms as may be found desirable and practicable, should necessarily accompany more specific efforts to battle with the pests and blights. 316. In the foregoing remarks, atone or two places, I have already pointed out that the brief term of my explorations and the facilities of observation and investigation afforded, do not justify any attempt being made to deal with the pests and blights in a strictly scientific manner. It maybe remarked that there are perhaps a dozen enemies of serious moment. The others, while occasionally doing considerable injury, are, nevertheless, of a local and accidental character. To solve the life histories of the dozen serious pests and blights, might take several years' patient study. To discover means of dealing with them, would occupy much time and necessitate detailed and elaborate experiments. LI. Sources of Information and Assistance. 317. In presenting the observations which I now propose to offer it may be as well to explain the chief sources of information and assis- Tea Pests and Blights. 179 Sources of Information and Assistance. tance which have been drawn upon in the study of the pests and blights of the tea plant : M/. The Journals and Proceedings of the Agri.-Horticultiira Society of India, more especially from 1865 to 1885 the period of greatest interest by the Society in the subject of Tea Pests. 2nd. Special publications on the India Tea Industry, including the annual Reports of the Indian Tea Association from 1882 to 1896. 3rd. Newspaper correspondence from 1873 to present date, more especially the letters which appeared originally in the Tea Gazette, but which may now be conveniently consulted in the Tea Cyclopaedia and the Tea "Planter's Vade Mecum. I have only incidentally referred to Ceylon newspapers for information, but the Tropical Agriculturist has been found of great value in confirming or correcting information regarding India. 4th. The Indian Museum Notes, more especially Mr. E. C. Cotes Account (in Vol. III.) of the Insects and Mites which attack the Tea Plant in India. $th. The invaluable aid of Mr. W. T. Thiselton Dyer, Director of Kew Gardens, London, and of Mr. George Massee, Cryp- togamic Botanist to the Herbarium of Kew, for two reports on certain fungal blights collected by me. Through the kindness of the Director General, Medical Department, I have been favoured with proof copy of Dr. D. D. Cunningham's forthcoming paper "On Certain Diseases of Fungal and Algal origin affecting. Economic Plants in India ; " in that paper three of the diseases of the tea plant have been dealt with and consequently drawn upon very largely by me. The liberal assistance of Sir George King and of Dr. D. Prain of the Botanical Gardens, Calcutta, for helping me with the deter- mination of the plants collected during my tour in Assam. This every now and again has been of value in connection with the present report as, for example, in giving the names of the plants on which certain tea blights were found in the jungles. The very great assistance, most generously afforded, by Mr. E. E. Green, the distinguished Entomologist of Ceylon, who has for many years identified himself with the study of the tea pests and has in consequence discovered and investigated the life histories of a large number of very obscure species. Mr. Green has not only examined and reported on a complete series of the insect 12 A SOURES General. Botany. Entomology. i8o' Report of Investigations in Assam The Tea Pests and Blights. SOURCES INFORMA- TION. Co-operation Planters. Conf. with paras. 19, History of Appearance. Advantagesof Exchange of Opinions. Interest first Aroused by Mr. Peal. pests collected by me, but has in return presented a most valuable set of the pests collected by him in Ceylon. As types of the species he has named these have proved invaluable. Similarly I am much indebted to Dr. A. R. 8. Anderson, Officiating Superintendent of the Indian Museum, for having examined the doubtful specimens referred by me to the Museum for determination, and to Mr. Edward Barlow, the Assistant in charge of the Entomological Collections of the Indian Museum, for having very kindly worked with me during the time which I spent in comparing my specimens with the Museum sets. 6th. But a debt of gratitude is more especially due to the large circle of planters whom it was my good fortune to meet during my tours and from whom I obtained much valuable assistance. Added to all these sources of information I may mention the files of correspondence of the office of Reporter on Economic Products which have been freely drawn upon and, lastly, the results of my own personal explorations. 318. The account to be given below, therefore, of each species of pest or blight will be made, as far as possible, to embrace the entire available information. Stress will be laid on the effort to trace out the locality and date of first appearance, of each of the more important enemies of the tea plant, from the belief that particulars of that nature may very possibly be found of value in future in- vestigations. I am fully conscious, however, that defects will be discovered, and can only hope that the present review of informa- tion may stimulate greater attention being given, more especially through the planters themselves once more making the technical journals of the day the channels of recording their observations and opinions. The apathy that has existed, for the past score of years, in the matter of exchanging ideas, largely accounts, lam afraid, for the want of progress. Interest may be said to have been first prominently aroused in the subject of pests and blights by the late Mr. 8. E. Peal's : paper on "Mosquito" or, as he loved to call it, the " Tea Bug. " Prior to the appearance of Mr. Peal's paper it had been vaguely designated " Blight, " and was viewed as a mysterious visitation. Mr. Peal showed that it was caused by an insect. Immediately there arose the enquiry as to methods of extermination. From that date one discovery after another followed quickly until for twenty years or thereby the Journals of the Agri-Horticultural Society and the public newspaper of Calcutta teemed with letters and detailed Tea Pests and Blights. t8i Sources of Information and Assistance. reports on the pests and blights of the tea plant. Gradually, how- ever, the subject seems to have lost interest, perhaps, through the dis- covery of new methods of cultivation and manufacture, that gave hand- some returns in spite of the ravages of these enemies of the industry. Left thus to themselves they have multiplied and extended until attention has been forced once more to the question, which twenty years ago was discussed and pigeon-holed, by those most interested, viz., the desirability of securing scientific assistance.* 319. In presenting this compilation of available information I may as well explain that I shall deal// with the Pests, and next with the Blights. Under Pests (Insects) I shall, as far as possible, follow the classification and the scientific determinations given in Mr. Cotes Insects and Mites which attack the Tea Plant in India. It may, how- ever, serve a useful purpose, if I attempt to indicate : (a) The insects described in the Indian Museum Notes (including Mr. Cotes' special paper) as actually found on the tea plan in India. (The pests of this section will for the most part be found dealt with in Mr. Cotes' Insects and Mites, etc.) (b) The insects found on the tea plant in Ceylon and which presumably may in the future be found in India. (r) The insects discovered by me in addition to (a) and includ- ing also those which prior to the date of my explorations have been treated under the position () above. 320. These particulars will be brought out by the letters (a), (b) or (c) being placed alongside of the serial given to the species dealt with. My object in so doing is to exemplify once more the very remarkable fact that the pests and blights of the tea plant are rapidly becoming diffused over the. world's areas of tea cultivation. A large percentage of these insects have never been seen by entomologists, except on the cultivated tea plant, though many are common enemies to both tea and coffee. It need hardly be repeated that these very striking circumstances point unmistakably to cultivation having produced the conditions necessary for the appearance and distribution of these pests, the more so since the wild tea plant has been found to bear but a small percentage of these pests. (Con/, with paras, n also 44 to 49). ASSORTMENT COLLEC- TIONS. Scientific Officer to I Investigate Blights. * See Proposed Scheme, Journ. Agri.-Horti. Soc. Ind., Vol. V. N. s. Proc., 24th Aug. 1876; 23rd Nov. ; 2ist Dec.; igth April 1877; 23rd Aug.; Vol. VI. Proc., i8th Dec. 1879 ; Scheme Abandoned, 22nd July 1880. Explanation of Letters Affixed to Names of Pests and Blights. Diffusion of Tea Pests. Small Per- centage on the Wild Tea Plant. 182 Report of Investigations in Assam The Coleoptera or Beetles. 321. As a matter of convenience, I shall quote (at the end of the paragraph of references under each species) the registration numbers assigned to all pests collected by me and, when preserved in fluid, shall quote also the numbers engraved on the bottles or tubes in which they have been stored. These numbers, it will be under- stood, are given for Museum purposes only, and are of little interest to the general reader, except as indicating by their absence pest and blights of which specimens have not been procured and of which contributions would, therefore, be very acceptable. COLEOPTERA. LII.-The Beetles. 322. In this Order of insects both the grub and the perfect beetle may injure crops. The maggots or grubs are sometimes devoid of legs, but more frequently have three pairs of jointed legs one pair on each of the three segments of the body near the head, and a pair of sucker-feet near the anal extremity. The chrysalis looks like a deformed beetle, curled up and motionless. The perfect insect or beetle has an upper pair of hard wing-cases, called the elytra, and below these a pair of large membraneous wings that fold underneath the wing-cases. There would seem to be five well-known species of beetles found on the tea, with perhaps three or four more that might be regarded as occasional enemies. The Cockchafer, or White Grub, in its larval stage eats the roots of the plant, and in its mature form would appear to devour the leaves as well. Then there are at least four species of leaf-feeders, that often do considerable damage to the crop, when prevalent. Lastly a wood-borer found in Ceylon, but not as yet in India. In Sibsagar district I came across a longicorn grub which is perhaps a by no means an uncommon tea-borer, though, so far as I can discover, it has not as yet been described. I. (a) Lachnosterna impressa, Burm. THE COCKCHAFER OR WHITE GRUB. References, Tea Cyclopaedia, 44; Notes on Tea in Darjeeling, 54 ; lea Planter s Vade Mecum, p. 105 ; Bomber, Ghent, and Agri. Tea, 342: Ind. Mus Notes, Vol. /., 59 ,. Vols. 11., 149 ; III., 3, 122: (.otes, Ins. and Mites on Tea Plant in India, 5-7. (Reg. No. 21, tubes Nos. 264 and 233.) Tea Pests and Blights. 183 The Cockchafer or White Grub. 323. HISTORY. -The first mention of this beetle, as an enemy to the tea plant, so far as I have been able to discover, is contained in a letter by a Darjeeling Planter (1874) which will be found reprinted in the Tea Cyclopcedia. The author of Notes on Tea in Darjeeling (1888), gives it the vernacular name of Kumla. Mr. Bamber says. " it occurs in all the tea districts," but does not tell us whether he had actually found it in Assam. Moreover, he makes the somewhat puzzling remark, "with the aid of lamps collecting the grubs at night when out to feed, would probably prove a satis- factory method for lessening their numbers. " So far as I am aware the grubs of this beetle never under any circumstance come above ground and have no occasion to do so since their food consists of the young roots of the plant. Mr. Cotes remarks that it appeared in vast numbers in Darjeeling in 1891 (vide letter from Messrs. Davenport & Co., October 1891, Ind. Mus. Notes, 111., j). "Its prevalence in other years," Mr. Cotes adds, " is shown by the fact that in 1883 no less than 2,695,000 individuals were collected and destroyed in the public gardens, Darjeeling (vide Ind. Mus. Notes, Vol. I., 59). But Mr. Cotes makes no mention of its being found in Assam. It was collected by me in a few gardens of the Sibsagar District, more especially at Khumtai and Ljgri Pukri. Mr. Crole (Tea Text-Book, pp. 84 and 222) incorrectly gives the scientific name of this beetle to the cricket. 324. DEPREDATIONS. Like most of the predatory Melolonthin beetles this species lives in its larval stage on roots. The eggs are laid in the ground. From these the white grubs escape and very possibly attack the roots of weeds in the first instance. Ultimately they penetrate to the depth at which they are able to discover the roots of the tea plant and these they devour. Mr. Cotes suggests that the eggs are likely to be laid about the begin- ning of the rainy season, in Northern India. " How long is spent by the grubs in the ground before they become full grown we do not know, but the fact that the European species Melolontha vulgaris, Fabr., spends more than three years in this stage, while the Ameri- can species, Macrodactylus subspinosus, Fabr., spends the greater part of one year, leads to the supposition that an equally long period may be required in India." (Co/es.) A tea-planter whose opinion will be found quoted below under the paragraph on LACK TER IMPRI FOS- 2.695.COO Destroyed in 1883. Discovery in Assam. Grubs Live on the Roots. Existence. i8 4 Report of Investigations in Assam The Coleoptera or Beetles. " Remedy," thinks the Indian white grub may live in the ground for two or three years. At all events these grubs never come to the surface until after they have passed into the pupal stage, when in due course they emerge as the mature or copper-brown-coloured beetle. At Khumtai on the 7th of April I witnessed this insect making its escape from the ground and found several of the mature beetles apparently eating the leaves of the plant. A large assortment of grubs in all stages of growth were sent me in December 1895 from another garden in the Sibsagar District. These were turned up while heavy hoeing, and the manager very properly thought that they had better be picked out. He accordingly sent me a selection and desired to be informed if they were insects reported hitherto to injure the tea. These larvae I submitted to the Entomological Department of the Indian Museum, as there seemed to me to be at least two, if not three, species. The reply obtained was to the effect that " the larger grubs are the larvae of a Melolonthin beetle probably belonging to the genus Lepidiota, and the smaller are apparently the immature forms of Lachnosterna impressa. The mud ball sent is the pupal cell of a Copris beetle. " Mud balls or nodules, of the size of a large hen's egg, are frequently thrown up from the ground, during the hoeing of tea gardens, when the soil consists of a fairly heavy clayey loam. They are commonly seen on the faces of road cuttings and may easily be mistaken for the mud cells of queen white-ants. On being broken open they will be found to contain a grub of a brown colour that may some- times be 2 to 3 inches long. The nodules are stratified and closely compacted, the inner layer being sometimes of a darker colour than the outer layers. It would thus appear that in Assam there are possibly two species of beetle that attack the roots of the tea plant. Grabs of the nature mentioned should, therefore, be carefully picked out from the ground during hoeing. 325. APPEARANCE OF THE BUSH. When beetles of this family attack tea, the plant at first is seen to have lost its vigour. The buds often become lanjhi, and as the ravages of the beetle advance the leaves dioop, turn brown and finally the bush appears as if killed and it may actually be so. The appearance in fact is very similar to that when a wood-borer is at work (such as Zeuzera coffeae), with this difference Tea Pests and Blights. 185 The Cockchafer or White Grub. that the whole bush appears to bef suffering instead of one portion of it only, as is generally the case with borers. From what has already been said, of this beetle, it will be understood there may be very little evidence of its ravages for months, while the grubs are steadily sapping the life of the plant and not one plant, for, as a rule, the beetle, if present, invades a considerable area, so that a whole plot of tea may be seen to be injured and clumps of bushes killed. When this occurs, the bushes if dug up will very often be found to have the roots invaded by fungi, and the inference is sometimes drawn, though incorrectly, that the fungus is the cause of the destruction. When bushes are seen to die in the manner indicated, it would be a good plan to have a healthy bush, near to those killed, dug up and carefully examined. It may then be seen that the fungus is only saprophytic, that is to say, a species that attacks dead, not living, plants, and that the real cause of the death of the bushes is the white grubs that may then be found feeding on the living roots. 326. REMEDY. So far no cure has been discovered, except to dig up the grubs and kill them. But to check the multiplication of the pest it is necessary to catch and destroy the beetles. For this purpose children, armed with insect-collecting nets, would be found most valuable, when incited through the offer of a reward for the number captured. The planter whose letter first drew attention to this pest, tells us that he offered a reward to his coolies, when hoeing the land, of one pice for every 30 grubs collected. In consequence the coolies dug more than their day's task, so that the collection of the grub practically cost nothing. He informs us, however, that " to clear 15 acres cost in pice 8108 giving 2 lakhs of grubs which filled two hogsheads. The eggs from which these grubs sprang must have been laid some two or three years before, and most likely they have quietly been doing great mischief. I am in the habit of burying the jungle not all over the land, but in small holes, here and there, where convenient. This I found a great trap, for the grubs left the tea trees to attack this rotting vegetation and so were easily collected." The author of Noies on Tea in Darjeeling gives somewhat similar information, though he adds certain additional facts. The grub, he says, is " generally found in very rich soil, or where manure has been put down, or much jungle has been buried. This is fairly destructive to young cultivation and seed-beds, and LACHNOS- TERNA IMPRESSA. Destruction of Mature Insect Desirable. Collection of the Grubs. SSSSL Burying Weeds. Effects of Manure. 1 86 Report of Investigations in Assam The Coleoptera or Beetles. eats off the roots of the young seedlings before they harden up, in some cases killing off nearly every plant in young cultivation. Only remedy digging up. Plants attacked by Kumlas generally die slowly, first getting yellow at top and gradually dying down. Never fill in a vacancy thus caused without digging the insect up." Mr. Cotes tells us that in Ceylon, on coffee estates " where Melolonthini larvae at one time proved very troublesome, the only method of treatment that seemed to have been at all successful was digging out the grubs by hand." Speaking of the efforts made to extirpate an allied insect from the vines in Europe, bisulphide of carbon is said to have been used with success. Miss E. A. Ormerod's Text-Book of Agricultural Entomology, pp. 80, 89-93, ^11 be found to give many useful hints regarding Cockchafers. Mr. Saunders (Insects Injurious to Fruits) gives some valuable particulars regarding a species of Lachnosterna said to be injurious to the cherry, plum, and other such trees. During the day the beetle remains in repose, but at night becomes active, and, if numerous, rapidly defoliates the trees. They are best collected by placing a sheet below the bushes, during day time and then shaking when the beetles fall into the cloth, and may be collected in large numbers. He then adds that where the beetles are found abundantly the grubs may be expected to remain for some years to come since the larvae eat the roots during a protracted period of existence. The presence of this beetle even if it does not eat the tea leaves is a very dangerous prognostication of future injury, and it should, accordingly, be collected and destroyed as much as possible. 2. (a) Diapromorpha tnelanopus, Lacord. THE ORANGE BEETLE, sometimes called PEAL'S BEETLE. References. Journ, Agri.-Horti. Soc. Ind., Vol. //. n. s. Proc., Nov. ij, i86g, page ix ; Vol. IV. (n. s.) Proc., iqth Sept. i8'/2, xl ; Feb. 27th, i8js, p. mi: April 24th, 1873, p. xxii ; Vol. V., Proc., 27th Aug. 1874, p. xlvi. ; Vol. VI.. Proc., 24th July 1879, p. xxii ; (Samples from Moran), identified by F. Moore, Proc., 2$th Sept. 1879, xxx ; S. E. Peal, in Tea Cyclopaedia, pp. 35-36 ; Notes on Tea in Dar- jeeling, 52 ; Bamber, Chem. and Agri. Tea, p. 242 ; Indian A/us. Notes, Vol. I., 1 06 ; //., 154; Cotes, Ins. and Mites on Tea Plant, p. 7 ; The Planter, June 2oth, 1896 ; Crole, Text-Book, p. 222. (Reg. No. 75, tube Nos. 62 and 272.) 327. HISTORY. It would appear that Mr. E. L Edgar, of Cossipore Tea Estate, Cachar, was the first to draw attention to this beetle. He Tea Pests and Blights. 187 The Orange Beetle. then wrote, that it had only appeared this year (1869) in any numbers. We next hear of it in 1872 from Moran in Sibsagar District, Assam. Both samples were sent through the Secretary, Agri.-Horticultural Society of India, to Mr. F. Moore, who identified them as being Dia- promorpha melanopus. Mr. Peal sent samples of it to Mr. Wood Mason along with such nctes and coloured drawings that Mr. Wood- Mason undertook to write for the Agri.-Horticultural Society an account of the insect, which promises, apparently, he never fulfilled, as I have failed to trace a paper by him. Mr. Peal himself, however, contri buted some interesting particulars in the form of an article on Tea Pests that will be found in the Tea Cyclopaedia. The subsequent historic facts are soon told. It was reported from Darjeeling by many writers, and Mr. Cotes says, " The species is a common one in India." 328. DESCRIPTION. A small orange-coloured beetle with the hard pitted wing-cases ; head slightly darker coloured than the body ; belly pale coloured. Size about fth inch in length. 329. DEPREDATIONS, This very troublesome little beetle is one of those examples of an insect having left its own natural food and taken to the tea. Its life history does not appear to have been traced out, but Mr. Cotes says, " From what is known of other species of the same family, it may be expected that the eggs are laid upon the leaves, that the larvae are active little creatures which feed upon the foliage, eventually transforming, in some sheltered corner, into stationary pupae from which the beetles ultimately emerge. These points, however," he adds, " require corroboration." Mr- W. J. Fleet sent me, from Salonah, Nowgong, samples of this beetle on the 2?th June 1897, which he collected on the i7th April, but had observed the beetle subsequently up to date of his letter. The winged insect was collected by me at Nigiriting on the ist of May, and in the Sibsagar District some weeks earlier. I had a large supply sent me from Sonada, Darjeeling, in June 1897. The first two letters announcing the discovery of this pest make no mention of the date of appearance of the beetle, but these letters were pub- lished, the one on the i7th November 1869, the other on the igth September 1872. It is curious that no writer makes mention definitely of the dates of appearance and disappearance of this pest. The above facts have been mentioned to show all that is known on these points. It may, DIAPRO- MORPHA MELANOPUS. Small Orange- Coloured Beetle. Eggs Laid upon the Leaves. Dates of Appearance. Periods of Appearance. i88 Report of Investigations in Assam The Coleoptera or Beetles. DIAPRO- MORPHA MELANOPUS. Mature Beetle, not Larvse, Feed on Tea. Appearance of Shoots Eaten. jstained. Presenceof I'lu Grass Dangerous. therefore, be presumed that its period of depredation extends, say, from the beginning of April to about the end of August. One point there seems to be no doubt about. The insect does not lay its eggs on the tea, nor do the larvae feed on tea. It is only the mature beetle so far, that has been seen on tea. I questioned the late Mr. 8. E- Peal on this point carefully, and he assured me that it certainly did not breed on tea, but, in his opinion, lived its early life on ulu grass (Imperata arundinacea). Regarding the manner of its depredations there can be no doubt. Mr. Edgar, its original discoverer, says, " These insects scrape the green stem below the Pekoe or Pekoe-Souchong leaf, sometimes below the Souchong leaf if the flush is quick grown, and the stem soft. They scrape or eat a place on it from half an inch to one and a quarter inch in length and from just touching it to three-fourths through. According to the depth they go, so soon do the two or three leaves above tumble over and wither. Should they multiply, they will be very destructive to new flushes." The Assistant Manager of Moran Company, Assam, in his letter even goes more fully into the subject. He says, " So serious is it that I estimate a loss of at least a maund of tea from this flush alone, which I am now plucking, and the loss on the entire year must be very serious." " The insect eats or gnaws only a small portion of the stem of the young shoot, which, whenever the sun touches it, withers, droops, and in about a day falls off and then the shoot looks just as if it had been plucked ; so that to discover the entire depredations of this little pest, the bushes have to be examined once or twice every day." Mr. 8. E. Peal's original account of this pest is also worthy of being quoted, since it throws some additional light on the methods of procedure adopted by this insect. " Naturally, " he says, " it is a grass-eater, and may be found in considerable numbers where larger grasses abound in the open. It has a habit of alighting on the tips and flies rather slowly, resting under the curved-over tips of the ulu grass. These insects are at times found in threes or fours, and rest there in the little shade afforded. In attacking tea, they generally eat away portions of the green stem of the shoot that is just fit to pluck ; the shoot falls over, withers, dies, and turns black and dry. If this beetle is at all common, considerable damage is done, and a garden or patch of tea presents a brown, withered appearance. As the portion eaten out Tea Pests and Blights. 189 The Orange Beetle. of each stem is not large, a single beetle may ruin half a dozen shoots as one morning's work." The author of Notes on Tea in Darjeeling says, "This is a small reddish yellow insect, which always runs up if cow-dung has been put down, and sometimes on new extensions, probably from the same cause. This beetle seems to attack heavy pruning or young tea more than pieces. It bites the shoot low down, and the shoot then withers and rots away. If there is sun-grass near the tea, the beetle goes to the grass, instead of the tea." Mr. Bamber did not evidently give much attention to this pest as he devotes only some two lines to it and says, ''at present the damage done has been small." Mr. Cotes (Insects and Mites, etc.) gives no particulars as to its depredations, but refers to the Indian Museum Notes, Vol. /., p. 106, where it is stated that specimens had been received from Mr. 8. E. Peal in 1885. A Darjeeling correspondent in The Planter says, " Often when reading articles on tea blights I have bee'n surprised never to have seen the ' Orange beetle ' mentioned. " " I have often seen a dozen or more of these beetles on one bush and every bud lying over dry and making the bush look almost as though withering up at first sight. Another peculiarity about them is, that they only seem to go for the Assam jats, and are scarcely ever seen on a China bush, evidently preferring the more succulent shoot of the Assam bush to the less juicy one of the China." The fact of this insect showing a decided preference for the Assam tea is a point of considerable interest. This I had recorded in my diary and found, when in Assam, that Mr. Peal and others had made the same observation. 330. REMEDY. In consequence of our ignorance of the early his- tory of this insect, only the one cure is open for consideration, namely, to collect and destroy the beetle. This Mr. F. Moors recom- mended over 20 years ago, and nothing further has been brought to light. Mr. Peal was of opinion that far from ulu grass being a protection (as suggested by the author of Notes on Tea in Darjeeling) it is the chief cause of the mischief. While walking through one of the Moran Company's gardens Mr. Peal stripped the long blades of ulu grass through his hand and demonstrated to me thereby the day habitat of the insect. But while Mr- Peal speaks of the insect accomplishing its ravages in the morning I found the insect in the Golaghat DIAPRO- MORPHA MELANOPUS. Attack Young Tea. Prefers Assam Jata. Conf. with paras. 49 r 71-2, 198. Early History Not Known. Hoars of Eating. 190 Report of Investigations in Assam The Coleoptera or Beetles. Sub-Division most active late in the afternoon. It is thus probable that it feeds both in the morning and in the afternoon. A planter whose letter originally appeared in the Tea Gazette, says, " I have had thousands of bushes damaged by this insect, and find it pays ' hand over fist ' to give coolies so much for catching the little pests, say a pice for fifty. By so doing I have succeeded in destroying as many as 20,000 in the day." Mr. Peal says, " eight or ten well-made butterfly nets, depth, say, 18 inches, and diameter of mouth i foot, ring or hook of sfout brass wire, bent, soldered and inserted in 4 feet high bamboo handles. These in the hands of as many smart boys will bring down the numbers very rapidly. If at all plentiful, a boy can easily ' bag ' 300 beetles per hour, and where not much of a pest, I have taken several times myself at the rate of 250 per hour. A few days of this and the nuisance will abate very perceptibly." 331. LADYBIRDS BEETLE MISTAKEN FOR THE ORANGE BEETLE.-^ I desire in passing to warn those, unfamiliar with the appearance of the Orange Beetle, not to be too hasty in coming to the conclusion that any small orange-coloured or red beetle, found on tea, is the pest here dealt with, or " at all events has no business " on the tea and had, therefore, better be removed. While visiting a garden in the Sibsa- gar District, the manager informed me that some ladybirds that I had caught and was examining were Peal's Beetle. I assured him he was mistaken and that the ladybird was one of the planter's best friends. It was no good my protesting that he was mistaken for " some years ago they had caught that very insect by the thousands daily." Of course this was a case of mistaken identity. The insect to which he alluded, as having been collected, I found subsequently was the orange beetle right enough. The ladybird beetle is almost circular in outline and of a bright red colour with a few spots on its wing-cases. The orange beetle is a narrow elongated insect with a somewhat large and curiously truncated head, as if cut off abruptly. The wing-cases are of one uniform orange yellow colour throughout and seem as if some one had dabbed them all over with the point of a needle the surface of the wing-case being pitted. The wing-cases of the ladybird are perfectly smooth and polished. The larvae and even the mature insect of the ladybird beetle are carnivorous and feed for the most part on the black aphis (Ceylonia Tea Pests and Blights. 191 The Green Beetle. thesecola), and I believe also on the larvae of the mosquito and green-fly. I have watched ihem repeatedly devouring the black aphis, and been surprised that colonies of these curious aphides were not alarmed by the appearance among them of so formidable an enemy. They seem undisturbed and await their turn of destruc- tion perfectly unconcerned. The ladybird does not injure the tea in any way and should most certainly be encouraged, on no account destroyed, through the mistaken notion of its being the orange beetle. 3- (a) Astycus chrysochlorus, Wied. THE GREEN BEETLE. References. Indian Museum Notes, Vol. III., gg, 126; Cotes, Ins. and Mites, etc., 8. 332. HISTORY. I have given this insect the name of Green Beetle as a simple and characteristic description. M r. Cotes tells us that it " was sent to the Indian Museum in April 1892 from a tea garden in Cachar, where it was supposed to have been the cause of some injury to the bushes. It was said to strip the young leaves off the tea shoots." 333. REMEDY. Nothing further can be said than has already been mentioned in connection with the orange beetle. The insect should be collected and destroyed whenever seen. As with all others so with this species, it may be said, that the sooner the pest is attacked the better. It is, however, unfortunate that we have to confess ignorance of the actual life history of this beetle. 4. (c) Astycus lateralis, Fabr. (Reg. No. 1 02, tube No. 131.) 334. HISTORY. Messrs. Balmer Lawrie & Co., on the 3rd of June 1897, were good enough to forward to me a few beetles that had been sent to them from the manager of the Hukanpukri Division of the Jokai Company's estates. Mr. E. Ramsden in forwarding the specimens reported that they had been found on one-year-old plants. They had come during the night in thousands and simply stripped the bushes. Fortunately they were easy to catch. My reply identified the insect as a species of Astycus. Subsequently, however, on re- examining the specimens, I came to the conclusion that it might pos- sibly be a species already identified by entomologists. I accordingly sent the samples to Dr. Anderson, of the Indian Museum, and he was good enough to inform me that the name of the insect was as above ""SUSP Carnivorous. 192 Report of Investigations in Assam The Coleoptera or Beetles. (A. lateralis). It is a much smaller beetle than A, chrysochlorus, is of a dark brownish black ground colour, with a distinctly green metallic tinge. The chief difference to the non-professional eye may be said to be that A. chrysochlorus is about f of an inch in length and is of a bright pale green colour, while A. lateralis is about half an inch long and of a dull metallic green. 335. REMEDY. There is nothing further to remark on this point than has already been said regarding A- chrysochlorus. 5 (c) Astycus ? sp. nov. (Reg. No. 101, tube No. 72.) 336. HISTORY. A black beetle with a metallic green tint, is not uncommon in Assam as a tea pest. At first I took this to be A. chrysochlorus, but, on comparing at the Museum my specimens with the beetle from Cachar, I agreed with Mr. Barlow that it must be regarded as a distinct and possibly an undescribed species. In point of size it is intermediate between A. lateralis and A. chry- SOChlorus, but in colour is more like the former than the latter. I was shown specimens at Amguri, by Mr. Buckingham, which he had collected some time prior to the date of my visit. The insect had not appeared very severe but was known all over the Sibsagar District. It came one year, gave considerable cause for anxiety, and then disappeared for a number of years, perhaps to re-appear when least expected. 337. DEPREDATIONS. At Dirpai, North Lakhimpur, on the 8th July I found a colony of this beetle doing much damage to some 10 to 12 bushes all near each other in one portion of the garden. The beetle commences on the margin of the leaf and eats downwards towards the midrib. When about half way down it commences on a new place, so that great ugly holes are cut out of the leaf. REMEDY. Same as for the other beetles dealt with under this genus. 6. (b) Xyleborus fornicatus, Eichhoff. WOOD-BORING BEETLE. Reference. Indian Museum Notes, Vol. IV., p. 57, Plate V., Fig. 2 . 338. HISTORY. This curious little beetle has been found in Cey- lon to riddle the tea stems. Specimens were sent to the Indian Museum on the aoth January 1897 by Mr. E. E. Green, and were forwarded Tea Pests and Blights. '93 The Wood-boring Beetle. to Mr. W. F. H. Blandford, who identified the pest as the beetle above named. 339. DEPREDATIONS. Mr. G. Alston, Superintendent of Craig- head, Nawalapituja, who first drew Mr. Green's attention to this new tea pest, wrote that it appears mostly in patches. " Most of the trees show no outward sign of the pest, except when almost every branch is attacked, when they turn rather yellow and stop flushing. Young trees about two years old, before they are topped, often snap off at the spot where the borers have made holes for their entrance or exit. Strong vigorous trees in good soil seem to be very little affected by it, and threw out good red wood even from badly bored stems. On the other hand, poor plants on ridges or poor soil seem to naturally feel the effect of it quickly, though in no case have I seen a tree killed by it. Isolated branches die off, but new branches come out in their place. As a rule, you can only tell an attacked tree (except in the case of young plants, when the stems snap off) on pruning it, when the holes in the wood are very appa- rent. It (the beetle) does not attack the cut surface after pruning, but makes its entrance through the back. In the case of young red wood it very generally goes straight down the pith ; in older branches I have often seen the wood riddled as if a charge of snipe-spot had been fired into it, with only one or two minute holes in the bark for exit or entrance. And yet in the case of vigorous trees they seem to thrive notwithstanding. Since 1893 the pest has spread very much, and become more general, though I cannot say that I see much differ- ence in the fields that were attacked then." The plate quoted above is an excellent one, but if the reader possess a copy of Miss Ormerod's useful little Text-Book of Agricultural Entomology he will find (p. 100) an illustration of the very closely allied species X. despar which shows the ravages of the European species on the plum. 340. REMEDY. It would be dangerous to suppose that because strong, healthy, well-nourished bushes seem little affected by this pest that there is no occasion to take steps to secure its eradication. Should it appear in the Indian tea areas, every effort should be at once made to stamp it out. Improve the vigour of the plant by manuring, deep drainage and other means. Lop off and burn all affected parts. If found in a small compact area I personally should, however, prefer to fire the plot. In my experience this is by far the 13 YLEBORUS iRNICATUS. Branches Die off. Entrance Made through the Bark. Vigorous Trees do not seem to Suffer. Should be Instantly Eradicated. 194 Report of Investigations in Assam The Tea Pests and Blights. TANYMECUS Fire might be resorted to. most effectual remedy with all diseases that occur over fixed and limited areas, more especially if the disease is recognised and the firing can be accomplished early in Spring. All over the plot dry straw should be placed within and through the bushes so as to secure rapid combustion. The embers should be at once cleared away from the bark of the main stem. After the fire has burned out, the bushes should then be pruned and all charred portions removed. The Spring shoots may be delayed a few weeks, but in exceptional cases only will the bushes be killed, unless the firing be done late in the season. LIU. Other Beetles Reported as Attacking the Tea. 7 Curculio tanymecus. 341. In the Journal Agri.-Horticultural Society of India, VoL VI. . s . Proc., 24th July 1879, mention is made of a beetle sent to the Society by Messrs. Williamson, Magor & Co., "as doing much mischief to the tea bushes in the Munguldye Company's plantations. " The specimens were forwarded to Mr. A. Grote and ultimately submitted to Mr. F. Moore. The reply appears in the Proc. of the i8th Decem- ber 1879. "The green beetle sent to you by the Munguldye Company is a Curculio allied, as Moore thinks, to C. tanymecus, but these beetles ordinarily bore into the stem and branches of plants and do not meddle with their leaves." I am unable to trace the name C. tanymecus. There is a genus of beetles known as Tanymecus, but Gemninger and Harold make no mention under Curculio of a species C. tanymecus. 342. It is somewhat significant that the pest alluded to, in above correspondence, should apparently have disappeared while two species of Astycus (that are by no means remote from Curculio) should have taken its place as leaf-defoliators in Assam. 8. Two other species of beetle have been sent to me by Mr. Fleet, as injurious to tea, viz., Crioceris impressa and Oides bipunctata. I have obtained no particulars regarding these beetles, and mention them purely in order to suggest further enquiry. 9 Grubs of Lepidiota and of Copris have been mentioned above (p. 184) as having been sent from a tea garden, but in addition I have before me now a third grub, viz,, that of a Longicorn beetle {Reg. No. 103} which has been reported as doing much injury to the tea. The Longicorn (CERAMBYCID) beetles are mostly dangerous wood-borers. Tea, Pests and Blights. '95 Lepidoptera (Saturnidae). CHAPTER XL LEPIDOPTERA. LI V. The Moths and Butterflies. 343. It is perhaps hardly necessary to explain that the insects of this Order pass through three complete phases. (a) In the imago or perfect phase they have, as a rule, two pairs of wings, and these are coated with minute and variously shaped scales, hence the name Lepidoptera. () The caterpillars that emerge from the eggs con- stitute the second phase, and it is these that are destructive to crops, the perfect insect being, as a rule, quite harmless. The caterpillar of a moth or butterfly is at once distinguished from the grub of a beetle by the possession of one to four pairs of sucker feet (or prolegs) placed near the middle of the body. (son, Fauna British India (Moths), Vol. I., 149-50; Green, Insect Pests of the Tea Plant, pp. 25-29, Fig. 6; Bamber, Chem. and Agri. of Tea, 244 ; Ind. Mus. Notes, Vol. II., p. 153 ; Cotes, Insects and Mites, etc., pp. 10-11. (Reg. No. 63.-) 353. HISTORY. Mr. Bamber remarks of this moth that it is " said to attack the foliage of tea and cocoa in Ceylon, also seen in Dar- jeeling." He then adds, "the damage done in India is very limited." Mr. Cotes, upon the above authority, gives this as a tea pest in Darjeeling. Sir George Hampson does not mention the species as found at Darjeeling. 354. DEPREDATIONS. -It was collected by me at Moaband on the 28th April, and the specimens, when shown to one or two planters, were identified as the caterpillar that some short time previously had done considerable damage to several gardens. At Amguri Mr. Buckingham had informed me that he had known the caterpillar do very con- siderable mischief. This species may, therefore, be accepted as one of those curious cases of spasmodic development that are of so frequent occurrence. An insect suddenly assumes alarming pro- portions and as mysteriously disappears again, for a number of years. The caterpillars of this moth apparently feed in the evening. They eat the leaves from the apex right down to the petiole, and deposit large curiously formed excreta on the leaves by which their presence may readily be detected. 355. DESCRIPTION. I was unfortunately unable to rear the worms collected and failed to find any cocoons, but I had Mr. Cotes' descrip- tion and figure with me at the time, and compared the live caterpillars very carefully with the drawing on page n. The insect found by me differed in some respects, so that I am disposed to think it may prove a distinct species. During day it sits in the curled-up attitude figured, by Green, and, as he very properly remarks, may then be readily mistaken for a brown withered leaf. It remains perfectly still. The LOBSTER LOBSTER CATERPIL- LAR. Sudden Development. a oo Report of Investigations in Assam Lepidoptera (Notodontidae). first pair of legs are much reduced and look like antennae. The next two pairs are greatly, one might say abnormally, elongated, and in the day attitude remain folded down at the knees so that they marvel- lously resemble the veins of a leaf, while the hindmost pair of prolegs appear never to be used for progression, but assume a fixed erect attitude, in imitation of the petiole of the supposed withered and shrivelled leaf. In general colour the creature may be said to have the chocolate brown tint of a fallen leaf, except for the rich, deep chestnut velvety patches and bands of white, that this remarkable creature possesses. But these are not unlike openings or perforations in the mimiced leaf. I came across nothing in Assam that struck me as being half so eccentrically formed, and can well understand that its configuration and attitude might easily be supposed to protect it from caterpillar- feeding birds. 356. It differed, however, from the description of the caterpillar of Stauropus alternus, sufficiently to make me suspect it may be a distinct species. The fifth, sixth and seventh somites had creamy white oblique bands, near their pointed and paired extremities, the eighth had no markings, while the ninth had a claret-coloured longi- tudinal band fringed on both sides with white. The tenth somite, instead of being pointed below, as in the figure given by Moore and by Cotes, was flattened and deflexed over the fourth pair of prolegs. The terminal somite was, as Sir George Hampson says, swollen and carried over the back (instead of being turret-shaped), but the anal prolegs were certainly not absent as Sir George says they are. These points of difference, therefore, seem to justify the inference that the Assam Lobster Caterpillar may not be Stauropus alternus, but, if so, it is certainly a closely allied species. Family SYNTOMIM:. 14- (c) Syntomis cyssea, Cram. References. Hampson, Fauna British India (Moths), Vol. I., 213. (Reg. No. 104.) 357. The caterpillars of this very plentiful Assam moth were found eating the tea leaves by Mr. J. A. Thomson, of Ligri Pukri, who was good enough to rear these and furnish me with the moth. So far this can hardly be called a tea pest, though it seems as well to record the fact that it had been found feeding on the tea plant. Tea Pests and Blights. 201 The Bag-worms and Faggot-worms. Family 15- (c) Pintia ferrea, Wlk. References. Hampson, Fauna British India. (Moths), Vol. I., 258. (Reg. No. 105.) 358. lam also indebted to Mr. J. A. Thomson for having furnished me with the moth of this species reared on tea. It is but rarely met with and can hardly be designated a pest. Mr. E. G. Green informs me that the nearly allied moth, Heterusia cingala, Moore, has appeared in Ceylon as a tea pest. " The caterpillars, he writes, have occasion- ally been very prominent, defoliating the tea over large acreages at a time. Fortunately, the caterpillar is very subject to the attacks of a Tachinid fly which usually prevents the appearance of a second large brood. From over a hundred living caterpillars sent to me from one infested estate, I only succeeded in breeding out three moths, all the others were killed with the fly which emerged in hundreds in my breeding cages. Some of the cocoons contained as many as twelve pupae of the fly apiece." LV. Bag-worms, Faggot-worms, etc. Family PSYCHID.E. 359. This Family of moths is, perhaps, the most dangerous of all Lepidopterous pests. There are many species found on tea in Assam and Kangra, a good few of which I have been able to identify, with Mr. Green's generous assistance, and the facilities afforded me at the Indian Museum. Others I have left for the present under their pos- sible generic designations. During my rapid tour through Assam, I was in many cases only able to collect caterpillars, and consequently have not got the complete series of worms, chrysalides and moths to enable me to name them. The notes which I wrote up in my diary regard- ing these tea pests may, I trust, however, enable the practical planter to recognize the forms to which I allude, and the filling in of their scientific names may, therefore, be left over for some future occasion. The bag-worms differ from all the other moths already described, in that the caterpillar forms around itself a small house by fastening together fragments of leaves, twigs or other portions of the tea plant. It thus snail-like carries its house on its back and pops inside on the slightest alarm. When it has reached its full growth, the bag or bundle of faggots is tied up to a branch. The worm then inverts BAG-WORMS. A Usoful Parasite. BAG-WORMS. Identifica- tion. Peculiarities. 202 Report of Investigations in Assam Lepidoptera (Psychidse). itsslf so as to bring its head where its tail was formerly, and there remains till the time comes for it to escape as a winged moth. But, as a rule, only the males become winged, the females continue within their little houses. The males come and mate with them and the eggs are laid within the house, thereafter the female dies. As a rule, there are only a few males and many females, so that insects of this family are rarely seen on the wing. Perhaps of a hundred cocoons that may be preserved in a breeding cage, so as to procure the males, only two or three will be obtained. 360. It is, therefore, most important not to regard the dead-looking old bags or faggot-houses as past any danger. They may be literally packed full of eggs from which a large progeny of young caterpillars would most certainly come forth. All should be collected and des- troyed. Mr. Green, in a letter to hand, remarks what it will be seen, from the description below, to be my experience also, that the smaller and more obscure members of this family are the most destructive as tea pests. 16. (a) Clania (Eumeta) crameri, Westw. THE FAGGOT-WORM. References. Hampson, Fauna British India (Moths), Vol. /., 291 1 Jour. Agri.-Horti. Soc. Ind., IV. n. s. Proc., 2gth May 1873, xxv ; June 26th, xxxi ; 2ist August, xxxi-u ; Vol. V., Proc., 3otk July 1874, xxxvi ; Peal, in Tea Cyclopaedia, 36 ; Green, Insect Pests of Tea, 3-8, Fig. 5 ; Bamber, Chem. and Agri. Tea, 243 ; Indian Museum Notes, Vol. I., 304; II., 757 ; ///., 133; IV. , 17-18, 41 ; Cotes, Ins. and Mites, etc., 14. (Reg. No. 24, tube Nos. 86, 261.) 361. HISTORY. It is a little difficult to be certain that this insect is actually indicated by the very obscure descriptions handed down to us by some of the earlier writers. Moreover, the next species (C. variegata) has been sometimes known to assume the same con- dition of a faggot-house. It seems safe, to believe, however, that Mr. G. F. Pinney, of Rungajam, in Assam, was the first to draw atten- tion to this as a tea pest, His letter which appeared in 1873, in the Journal of the Agri. -Horticultural Society of India, induced Dr. R. A. Barker to inform us that he had found it in the Darjeeling Terai. Perhaps the next notice of historic value is a letter fromTezpur, 1874, in which this insect is spoken of as having proved very destructive. Mr. Peal, speaking of the PSYCHID& says, one species makes its case of twigs. Mr. Green tells us that before the introduction of tea in Tea Pests and Blights. 203 The Faggot-worm. Ceylon, this psychid was common on coffee, so that it is an old offender. Mr. Cotes remarks that specimens of it had been sent to the Museum "from tea gardens alike in Sikkim and Assam." An old and experienced Cachar planter, to whom I showed my collec- tions of tea pests the other day, informed me, however, that this species, so far as he was aware, does not occur in Cachar, but that No. 1 8 (. 21) will serve at once to identify the insect though it is not good. The two antennse- like long tufts of hair on the head, as also the erect anal tuft, are each made up of groups of pectinate hairs of different lengths, so that the collective tuft looks as if jointed. Then instead of having what appears like six pairs of prolegs, in the middle of the body, there should only be five pairs. It is possible that one of these supposed pairs of prolegs is intended to represent a tuft of hairs. 429. DEPREDATIONS. The insect, like most of the members of the family to which it belongs, feeds for the most part during night. At day time the caterpillars hide below projecting corners of clods, in drains, or in rotten portions of the stem. They show a special liking for newly-planted-out tea, both in young gardens and vacancies. It is this feature of the insect that constitutes its chief danger. No person could walk through a garden in Assam without being struck with the remarkable fact, that, along roadsides where there may be young tea bushes, in vacancies all over the estate, or in new extensions, all the old mature leaves of the seedlings have been riddled to pieces. The entire intercellular tissue of the leaf has been eaten away and only a skeleton remains, corre- sponding to the midrib and veins. The young shoots and tender leaves are rarely attacked. The state of affairs that I have indicated is the work of this remarkably elegant hairy caterpillar, but you may look for days and see no signs of the depredator unless you examine carefully on the ground or return to the affected tea late in the afternoon. The following passage from my diary may be here given as descrip- tive of the chief peculiarities of this insect: 430. I went over Tiphook on 2ist April with Mr. J. Lawrence, Manager, and was shown some young tea recently planted out where all the older leaves had been eaten to skeletons and few of the younger leaves touched. No caterpillar or other insect had ever been seen feeding on these bushes, though fresh excreta could be found on the leaves, below those perforated. It thus seemed probable that the destruction was caused by a winged insect that came at some fixed time, say at night, and left in the morning. I accordingly suggested that we should revisit that particular new extension late in the afternoon. We accordingly returned at 5-30 P.M. in order THE INDIAN TEATUSSOCK Mr. Moore's Illustration of the Caterpillar. Prefer Newly- planted-out Tea. Leaves Skeletonised. 234 Report of Investigations in Assam Lepidoptera (Lymantriidae). to try, if possible, to discover the depredator. We had not far to go, the bushes were at once seen to have each one, two or more of the caterpillars of Dasychira (Olene) mendosa on them. These were carefully watched for at time, until it was fully established that these were the insects that had eaten out the intercellular tissue of the leaves until only skeletons remained. They were undoubtedly, there- fore, the pest we were in search of, and a curious discovery it was. On hearing us speak, these clever creatures desisted from their feeding operations, and turned their heads up in a curiously threaten- ing attitude as if both on the defensive and offensive. It was further discovered that this remarkably active insect hides in the ground and crawls up on the bushes late in the afternoon, so that it thus feeds mainly at night. 431. One cocoon was collected from the plot of young tea, but, though careful search was made, this was the only one seen. This had been spun of grey brown spinose hairs and was deposited on the under surface of two leaves drawn together. The hairs forming the cocoon were seen to be feathered and some of them to end in tufts, exactly similar to those on the back of the caterpillar, only twice as long or more. It would thus appear that the creature produces greatly elongated hairs on its back just before the time of passing into the state of a chrysalis. It cuts these off and builds its cocoon of them, but it must not only elongate the hairs but produce a very much larger quantity than it carries as a caterpillar. Two of the cater- pillars reared in the cage produced much smaller and less perfect cocoons to the one collected on tea, but otherwise identical in shape, configuration and structure. (I may here add that on the i5th May an Ichneumonid insect escaped from the cocoon found on the tea bush. (Tube No. 203.) 432. After having solved the problem of the injury being done to the young tea Mr. Lawrence drove me through a large portion of the garden, not visited in the morning. I found two young plants (filling up vacancies) remote from the new plantation mentioned above, and these were observed to have the leaves similarly reduced to skeletons and to bear Dasychira mendosa caterpillars. But though the neighbouring old bushes were carefully scarched.none of these caterpillars could be discovered on them. This insect thus shows an inexplicable preference for the older leaves of one or two Tea Pests and Blights. 2 35 The Indian Tea Tussock Moth. year old seedlings, and does much harm, therefore, to new plantation ; but it rarely, if ever, attacks old and well-established bushes. As the result of this afternoon's study, I was enabled to piece together observations made in many other gardens. I had frequently seen young tea planted out in vacancies or along roadsides, with the older leaves reduced to skeletons, but I could never ascertain the agent of their destruction. The practical inference, therefore, may be said to be that when planters find the leaves of new extensions riddled in the manner described, they should send out the " grub collectors " late in the afternoon, and instruct them to seek for these beautiful, clever, and timid, hairy enemies. 433. REMEDY. Collect and destroy the caterpillars and cocoons. Where the insect is found to be doing serious damage, it would be a good plan to give the surface soil a good dressing with dry lime and to immediately thereafter hoe the ground. Were this done in the early part of the day, it is probable that a very large percentage of the caterpillars would thereby be destroyed. In Europe Dasychira pudibunda (the Pale Tassock Moth) does much damage to the beech, oak, hornbean and alder. Mr. Biandford tells us (Schlich's Manual Forestry, Vol., IV. 274-2^ that the eggs are laid low down on the stem, about a yard from the ground. The caterpillars hatch in three weeks and make their first meal off their egg-like shells, and thus remain a short time in clusters. They finally ascend and skeletonise the leaves, but do not appear to come down to the ground during day time. In September or Octo- ber, however, the worms descend to pupate on the ground. The treatment often pursued is to girdle the trees with grease. If done before the hatching of the eggs, this would prevent the ascent of the young worms, and later on check the mature ones from reaching the ground. The suggestion, therefore, might be offered as worth trying, namely, to girdle the stems of the seedling tea plants in the manner here indicated. 3& (a) Dasychira, sp. 434- Mr. Cotes tells us that caterpillars identified as belonging to this genus were sent to the Indian Museum in 1886, from a tea garden in the Duars, where they were said to have caused serious damage by feeding on the leaves of the tea plant. Mr. Bamber, alluding THE INDIAN Collect the Caterpillars and Cocoons. Top Dressing with Lime. Eggs Laid on Stem. Pupate on the Ground. Girdling with Grease. Report of Investigations in Assam Lepidoptera (Lymantriidae). apparently to this same fact, under the name D. thwaitesi, Moore, says, that the insect had been " reported as doing much damage by defoliating tea and sal (Shorea robusta). The sal trees through- out 200 square miles of forest in Assam, are said to have been defoli- ated by it in 1878." 39. (c) Dasychira securis, Hubn. Reference. Hampson, Fauna British India (Moths), I., 453. (Reg. No. 109.) 435. The caterpillars of this moth were found by Mr. J. A, Thomson, of Ligri Pukri, feeding on tea. A few were collected and reared, and the perfect moths supplied to me. There is, however, nothing further to be said regarding this species than will be found in the foregoing remarks. 40. (c) Dasychira,^. 436. During my explorations in Assam I came across two other caterpillars on tea that, I presume, may belong to this genus. Regard- ing these the following passages from my diary may be here given : 437. (A) A caterpillar, apparently a species of Dasychira, was found at Sepon on the i5th April only one being seen. Ground colour brown with blue bands and orange-red spots. Over the third somite from the anal extremity there are two trumpet-like projections that each ended in a sharp red point. Then further up on the next two somites, two sea-anemone-like bodies of a yellow colour, each with a central depression. Over the space between the thoracic legs and the prolegs is placed a large compact tuft of grey-brown hairs that stand erect and connivent into a ball, while on either side of the head are ear-like red elongations. Altogether this is one of the most remarkable caterpillars found on the tea plant, but it had never been observed by any of the planters, to whom it was shown, so that it must be regarded as a rare pest. It belongs, however, to a family well known as crop depredators. 438. (B) A caterpillar obtained along with D. mendosa, on the Tiphook young tea : I could find only one or two. It was canary yel- low all but a triangular black band. Hairs radiating in tufts from elevated warts. In front of the black mark there was an erect tuft, and on either side of the head exceptionally large tufts of yellow hairs. Feet with cilia. There appeared to be no doubt that it was Tea Pests and Blights. Black Hairy Caterpillars. related to the caterpillar collected at Sepon, and was thus in all pro- bability a species of Dasychira possibly D. horsfieldi. 41. (c) Euproctis ? sp. nov. References. Hampson, Fauna British India (Moths), Vol. I., the genus, pp. 47i'4 8 4- (Reg. No. 85, tubes Nos. 156,211, 235.) 439. HISTORY. Through the kindness of Messrs. Finlay, Muir & Co. 1 had the pleasure to receive, on the i3th March 1897, cocoons and caterpillars of what appeared to be a new tea pest. From the cocoons, three badly formed moths were ultimately obtained. These Dp. A. R. 8. Anderson was good enough to have compared for me with the col- lections at the Indian Museum, with the result that they were pronounced to " probably belong to the genus Euproctis." I next sent a specimen of the moth and some caterpillars and cocoons to Mr. Green in Ceylon, and he favoured me with his opinion on them, namely, that " it was evidently a species of Euproctis." The speci- mens had been obtained from Mr. Harrison, Manager of Lebong Tea Estate, Darjeeling. 440. DEPREDATIONS. It may be worth while suggesting that this in all probability is the black caterpillar mentioned by the author of Notes on Tea in Darjeeling. On page 53 he says, it " sometimes clears every leaf off patches of 30-40 acres. This is the larva of a small white moth. It is a black caterpillar about \ inch long." That brief description corresponds very closely with the material fur- nished me by Mr. Harrison who writes, this is " a new sort of blight. It is a black -brown hairy caterpillar. It attacks the old leaves and strips the trees. It performs all its ravages at night, and hides itself under clods and stones during day. I have boys on catching some thousands daily. They appear on the dry ridges and are not found in any damp hollows. They have stripped the leaves some 50 to 60 acres of an adjoining garden, and are now attacking the bark. On lower portions of Lebong they have now appeared and are doing considerable harm. I fancy they will disappear with rain." 441. REMEDY. It will be seen that the method of attack and other particulars of this pest correspond in every particular with Dasychira mendosa above, and the treatment to be pursued should thus be the same as for that pest. Report of Investigations in Assam Lepidoptera (Hypsidae). 42. (c) Numenes siletti, Wlk. References. Hampson, Fauna British India (Moths'), Vol. /., 456. (Reg. No. no.) 442. This bright orange-coloured little moth is by no means uncom- mon on tea, though nowhere to the extent to be regarded as a pest. Family HYPSID^. 43. (a) Hypsa alciphron, Cram. References. Hampson, Fauna British India (Moths), Vol. I., 302. (Reg. No. in.) 443. This very common moth was found feeding on tea at one or two localities. The caterpillars were collected and reared for me by Mr. J. A. Thomson at Ligri Pukri, Sibsagar. It can hardly be said to be a pest, but no member of this family should be looked upon as harmless. Family ARCTIID^E. 444. This family of nocturnal moths are like the last characterised by having fairly large hairy caterpillars. It is probable that some half a dozen or more species are occasionally found on the tea plant, but none of them have as yet assumed a very definite position as tea pests. Mr. Cotes refers (Insecls and Mites, etc., p. 22) to a caterpillar of what, he presumed, might be a species of this family. The samples were sent to the Museum in April 1891 by Messrs. Andrew, Yule & Co. from a garden in Jorhat. " The manager of one of the gar- dens wrote that he had been getting twenty-five 2-md. bags of these caterpillars picked off the bushes daily, and, that in spite of all efforts, they seemed rather to increase in numbers. They stripped the leaves and the bark of the bushes to such an extent as in some cases to kill the plants. The manager added that, during the ten years he had been in the district, he had never seen such a visitation and that his coolie sirdars, some of whom had been over 20 years on the garden, could not remember the like." (Con/, with para. 487). 44. (a) Arctia ricini, Fair. References. Hampson, Fauna Br. Ind. (Moths), Vol. II, 77 . Ind. Mus. Notes, III. (6), 14. 445. In the Journal, Agri.-Horticultural Society of India {Vol. XI., Proc. 26th March 1897), p. 603, it is stated that Messrs. Andrew, Yule & Co., submitted to the Society samples of an insect sent by the Tea Pests and Blights. 239 Other Black Hairy Caterpillars. manager of the Singtom Tea Estate, Darjeeling. The manager wrote : " The Caterpillars are in millions here and are quite strip- ping the bushes of their old leaves." 45. (c) Creatonotus lactineus, Cram. References. Hampson, Fauna British India (Moths), Vol. II., 2. 243, 255 ; Ind. Mus. Notes, Vol. I., p. 204 } II., 165; III., 138 ; Cotes, Insects and Mites, etc., 28. (Reg. No. g, Tube No. 161.) 491. HISTORY. I have given the specific name these on the authority of the Indian Museum Notes, Vol. I., (//. ^r), 204. Mr Green was the first to draw attention to this insect as a tea pest Mr. Bamber alludes to it {Chemistry and Agriculture of Tea, pub- lished in 1893) in two places, once in its true position as a species oi DIPTERA, and again at the end of his account of Scale Insects. In both positions he .calls it Agromyla, obviously a misprint for Agromyza. It seems probable that the one leaf-mining insect which Mr. Bamber may have had in his mind, was the early stage o: Gracilaria theivora, the other, the insect which it is desired to exhibit in this place. But Mr. Cotes (Insects and Mites, etc., pub- lished, 1895} states that this insect "has not yet been recorded from India." It would thus appear that Mr. Bamber's remarks were no regarded as establishing the species as an Indian tea pest. It was found by me in every garden in Assam, and samples sent to Mr. Green, who has been good enough to examine them and to report that they are identical with the Ceylon insect. There is, therefore now no longer any room for doubt as to the existence of this tea pest in Assam. LEAF-MINING Con/, with para. 46 (9), 614. EAF-MINING FLY. Common Assam. Report of Investigations in Assam Hymenoptera. OCINIS THE^E. Found on Last Year's Leaves. 492. DESCRIPTION. The rough sketch opposite gives the appear- ance of a leaf, burrowed by this insect. After wandering about to a consider- able extent and devouring the tissue, below the upper epider- mis, the larva moves towards the margin and there pupates. The letter (a) Fig. 10, indi- FIG. 10. THE TEA LEAF MINING FLY. cates the pupal case. In Ceylon the larvae seem to form sinuous tunnels instead of burrowing and eating over a more or less compact space the habit of the Indian insect. 493. DEPREDATIONS. Fortunately this interesting little fly seems to prefer last year's leaves, and not more than one affected leaf here and there can be said to be met with, so that at present it has to be viewed as a curiosity more than a pest. At the same time I have found some gardens sufficiently attacked to suggest the undesirability of this fly being allowed to increase. Green tells us that the larvae lie from first to last in the single leaf upon which the egg was first deposited. " The action," he remarks, " of the little miner, while at work, can be distinctly seen through the thin cuticle of the leaf. It moves its head which contains a sharp cutting instrument in regular sweeps, like a mower with his scythe. At each sweep a portion of the cuticle is separated from the leaf and (presumably) a portion of the leaf is taken into the animal's body. It is a very rapid worker : a specimen under examination cleared a space more than twice its own size within half an hour's time." It may be here added, however, that several allied insects, such as the Hessian Fly on wheat, the Frit Fly on oats, the Turnip leaf- miner, the Rice Fly and many such agricultural pests, show that Tea Pests and Blights. 257 Red and Black Ant of the Tea Bush. mining flies cannot be despised. There can be no doubt that every leaf invaded, is destroyed to the plant, and the study of pests is beset with sudden and unexpected expansions, so that it would be unsafe to say that this minute parasite is incapable of ever becoming a source of anxiety to the tea planter. HYMENOPTERA. LXII.The Saw-flies, Gall-flies, Ichneumon-flies, Bees, Wasps and Ants, 494. This order of insects embraces a good few forms that are destructive to plants such as the Saw-flies and Gall-flies, but many others that are parasitic on plant pests, such as the Ichneumon-flies. It is somewhat curious that no species of Saw-fly nor Gall-fly has, so far, been recorded as met with on the tea. The members of this Order are all characterised by the possession of mandibles; wings when present in two pairs which, during flight, are often linked together so as to act as one pair ; and by the first segment of the abdomen being separated from the remaining seg- ments and united to the thorax, the attachment of the remainder of the abdomen being by a flexible joint. Two species of ants are commonly found on the tea plant. Some planters regard these as friendly. They are as follows : 58. () Cremastogaster contenta, Mayr. THE RED AND BLACK ANT OF THE TEA BUSHES. 495. HISTORY. This insect, while not hitherto apparently recorded as a pest of tea cultivation, is closely allied to Cremastogaster Dohrni, Mayr., which in Ceylon has been found to injure Cinchona, Coffee and Tea. It forms small, black-looking, mud enclosures, around the twigs, mostly near the bifurcations of the shoots. These may at first be only an inch in length, and contain perhaps not more than a dozen ants. In course of time, however, they gradually increase in size until they become from a foot to a foot and half in diameter, and then contain many thousand ants. The hive is constructed of a black papier-mache looking material, in which no doubt there is a large proportion of mud. It is formed more or less in layers, so it would appear when viewed from the outside, but, on being cut open, it is seen to be composed of a vast number of REDBACK Other Mining RED-BLACK ANT. Hives on Tea Bushes. Report of Investigations in Assam Hymenoptera. galleries of cells in every direction. There is no outer protecting membrane, and it is of one material throughout. 496. In one garden, in the Sibsagar District, the superintendent told me he believed most thoroughly in this ant as protecting the estate from insect pests ; accordingly, he would on no account have the hives removed. Every second or third bush had a large hive such as I have described, and one portion of the garden looked almost black owing to the immense quantity, large and small, of the hives borne on the branches. It was useless my saying that I was willing to undertake to collect as many pests in his garden as could be found in any other in the neighbourhood selected for the purpose of comparison. He believed in ants, and there was no getting beyond that fact. My visit lasted for an hour or two only, but I examined the bushes with considerable care to see if they enjoyed any special immunity from blights and pests. I could see no difference between that garden and the one or two neighbouring gardens I had been recently investigating. 497. DEPREDATIONS. As this ant is very frequent in Assam tea gardens, I took some little trouble to study it during the repeated occasions I came across it. A very large number of small nests will generally be found constructed on bushes badly affected by the Tea Aphis (Ceylonia theaecola). The head and thorax of the ant are of a bright brick-red colour ; it has two sharp spurs on either side of the middle portion of the "alitrunk" or first abdominal section attached to the thorax. The abdomen proper is of a somewhat triangular shape, pointed at the anal extremity, and, during the act of running, is carried in a strikingly erect and threatening attitude. Up and down the shoots these clever little ants may be seen to be traversing while paying their attentions to the aphis. Far, however, from eating that particular tea pest, they protect and even imprison it ; for this purpose they carry up some of the material of which their hives are formed and cement the leaves of the shoot around the aphis. It seems probable, there- fore, that new ant nests are formed around colonies of that aphis. It is the sweet exudation of the aphis that they are after, and they thus protect, rather than kill, the pest. I did not, however, come across a Lecanium or other scale-insect imprisoned, as Mr. Green tells us is the case with the Ceylon ant. ( Con/, with p, Tea Pests and Blights. 259 Ants found in Tea Bushes. 498. But they become pests themselves and of a serious nature. They injure the bark on the portions of the branches within their hives, to such an extent that the circulation of the sap is checked, the parts projecting above the hive are accordingly starved and rapidly die. On no account, therefore, should these ants be allowed to get established in tea gardens. The injury they do to the tea plant far out-weighs any possible help they may render, and their hives should accordingly be cleared off every bush upon which they are found. 59. (c) CEcophylla smaragdina, Fair. THE RED ANT OF ASSAM. 499. HISTORY. This is the common ant, seen on trees all over the province. It draws together a mass of leaves and unites them by a fine white silken web into a hive. It is capable of biting with con- siderable severity on being disturbed, and is accordingly a source of great annoyance to the women while picking tea leaf. It is no doubt a carnivorous insect, and might do good, but is distinctly objection- able. Besides which it cannot be healthy for the tea bush to have a clump of its twigs and leaves, perhaps 2 feet in length and breadth, tied up in the manner indicated. Flushing with that portion of the bush is quite out of the question, and I am much disposed to think that the two or three adjoining bushes, to a red ant's nest, are very likely to be neglected both by the pluckers and the hoers. 500. REMEDY.. The best way to get rid of both above species of ants is to place a small box over the hive and light a basin of flour of sulphur below. The majority of the ants will be killed, and in the morning the hive may then be cleared off, or the branch bear- ing it may be cut off. 60. (c) Wasps, 501. Various species of Wasps are occasionally found on the tea bushes, and should be killed and their hives removed in the manner described for ants. A small nest of red ants, lopped off and placed at night against a wasp's hive, will, I am told, be found an excellent method of dealing with wasps. Two or three ants attack each wasp, and in a few hours' time the entire swarm will be found dead. I 7 A REDBACK Injury effected. RED ANT. Source of Annoyance and Loss. WASPS. 260 Report of Investigations in Assam Orthoptera. ORTHOPTERA. LXIII.The Grasshoppers, Crickets, Locusts, etc. 502. As the name ORTHOPTERA implies, these insects have the wings folded lengthwise, the lower wings being closed fan-like beneath the upper pair. The body is more or less cylindrical, and the forelegs very often formed for burrowing in the ground. They accordingly dig holes, many of them living very largely on larvae and worms, others on roots, fruits and leaves. The Locust is, perhaps, the best known defoliator of this assemblage of insects, but to the tea planter the cricket is the most serious pest of the Order. It would seem proba- ble that there may be two or three species of Cricket, though I only met with one in Assam. 61. ( a ) Acridium peregrinum, Oliver. 62. ( a ) Acridium flavicorne, Fair. 63. (a) Catantops indicus, Saussure. LOCUSTS. 503. HISTORY. Particulars are given by Mr. Cotes (Insects and Mites, etc., pp. 43-44} of the above species. As I did not come across these pests during my brief explorations in Assam, I do not think it is necessary for me to do more than mention the fact that they have been known to injure the tea. Mr. Peal in a letter to the Tea Gazette says, " Lately part of my garden was taken possession of by many thousands of Locusts, apparently the same as those I have seen in flights in the hills of the North- West." " These insects did not feed on the tea, but they seemed to prefer the bushes to live on, and did a considerable amount of damage by walking over and appa- rently mouthing the young leaves, which, whenever the locusts touched them, turned black and curled up." 504. Mr. Cotes concludes his account of locust thus : " Acridiae of this kind are likely to lay their eggs in the ground. The larvae are active grasshoppers, which differ from the adult chiefly in being smaller in size and wingless. They are active throughout their entire existence, and devour the leaves of plants in large quantities." 64. (a) Brachytrypes achatinus, Stoll. THE CRICKET. References. Journ. Agri.-Horti. Soc. fnd., Vol. I, n.s. t i86g t Proc. i Qth Feb., p. xiii ; Tea Cyclopaedia, 40 Money, Tea Cultivation, Tea Pests and Blights. 261 Grasshoppers, Crickets and Locusts. 8g~go , Baildon, Tea In Assam, 46 ; Notes on Tea in Darjeeling, 55,- Ind. Mus. Notes, Vol. III. (pt. 5), 77 / Cotes, Insects and Mites, etc., 45. (Reg. No. 114.) 505. HISTORY. The earliest mention of the Cricket as a tea pest occurs in a letter of Mr. Peal's to the A gri. -Horticultural Society of India, dated i86g. A little later Mr. Peai wrote a paper on tea pests (that will be found in the Tea Cyclopaedia'), but omitted to mention the Cricket. Whereupon a Cachar planter wrote to the Tea Gazette drawing attention to this as a serious omission. Colonel Money devotes only a few lines to the subject of pests under the heading of " White-ants, Cricket and Blight." The fourth edition of his work appeared in 1883, so that even fourteen years ago the subject of pests and blights was regarded by the author of the Prize Essay on tea as practically of no moment. He, however, tells us that the cricket was very destructive to seedlings. The same opinion has been given by Baildon and by the author of Notes on Tea in Darjeeling (1888). Mr. Cotes mentions that the only occasion on which representatives of the insect had been sent to the Indian Museum was in July 1893 and from Jorhat in Assam. The figure (/>. 45) given by Mr. Cotes is of the immature insect, and is little more than one-half size of the full-grown cricket. Mr. Bamber makes no mention of the cricket, and Mr. Crole (1897) confuses it with Lachnosterna impressa. The cricket was collected by me in at least a dozen nurseries and young plantations, here and there all over the province. Mr. W. H. C. Whigham, of Hautley, Golaghat (to whom I am indebted for much valuable assistance), has sent me a dozen or more of the full-grown cricket and in excellent condition. It will thus be seen that the cricket is a very widely distributed tea pest, but so far we have apparently no mention of it from the Duars, Darjeeling, Kumaon, Kangra, nor from South India. Colonel Money's remarks may possibly be accepted as having special reference to Chittagong. There would seem every likelihood, however, that, although no special mention occurs of this pest outside Assam and Cachar, it possibly occurs throughout the Indian tea districts. 506. I have already remarked under Agrotis ypsilon (A. suffusa, Cotes, Insects and Mites') that the black grub may, in some instances, be the actual depredator, in some few instances where blame has been laid on the cricket. CRICKET. Widely 6 DIstrt- buted Pest. Possible Errors. 262 Report of Investigations in Assam Orthoptera. BRACHYTRY- PES ACHA- Seedlings. Sometimes Do Incalculable Mischief. Sometimes Attack Old Plants. Specially Abundant on Sandy Soils. Method of Capture. 507. DEPREDATIONS. Both these insects (the black grub and the cricket) have the same vicious habit of living in nurseries or new plan- tations. During night they emerge from their burrows to eat off the young stems. The seedling, in the majority of cases, is thereby killed. The Cachar planter to whom reference has been made above, wrote that "the Cricket is both common and very destructive in Cachar. It is about ij inch in length when full grown, and lives in small burrows sometimes singly, sometimes two or three in one hole. The burrows frequently penetrate to a great depth, and where the crickets are so numerous that it becomes necessary to dig them out (which some- times happens), the tunnels are followed a foot and a half or two feet, and even then not uncommonly without avail. The cricket feeds on the young leaves of the young plants ; and to obtain these, it cuts through the stem of the plant, about three quarters of an inch from the ground, and then carries off the top to his hole, so that each meal which the insect makes causes a vacancy ; where they appear in any number the destruction may be imagined. They will cut through a stem as thick as a pencil without difficulty, and amongst small plants in a nursery they sometimes do incalculable mischief. I have seen them attack an old plant, where they eat off the young shoots, and thus did a great deal of harm to the succeeding flushes ; but I have only once seen this occur." 508. The Director of Land Records and Agriculture, Assam, fur- nished the samples above alluded to, as sent from Jorhat to the Indian Museum. The following passage from the report on these may be taken from the Indian Museum Notes, in amplification of the above letter from Cachar. " The creature was observed to be specially abun- dant on sandy soil. If makes burrows from 9 to 18 inches deep in the ground, where it conceals itself during the day-time. In the evening it sits at the mouth of the hole, and may be recognized by its shrill piping." 509. REMEDY. So far as I know, there is only one way of dealing with this pest, namely, that generally pursued in Assam, namely, reward to the children to catch the insect. And they do this very cleverly. Armed with a straw or long flexible twig and a piece of bamboo, by way of a spade, they proceed to the nursery or new plantation. Having found a likely hole they insert the straw as far as it can go, and then proceed to dig down (following the straw) till they Tea Pests and Blights. The Cricket. come on the cricket. It might be desirable to substitute a soft copper wire for the straw, and, if properly used, the wire might even kill the cricket. Its use would not in any case necessitate such care to avoid cutting the guide, as is the case with a straw or twig. Poisonous fluids poured down the holes might also be effectual. In Europe the mole-cricket is captured by burying in the ground flower pots or other vessels with smooth sides mouth upwards. The crickets fall into these at night-time and cannot escape. 510. The life history of the Indian species has not been worked out, so that we do not know when the breeding season occurs. The eggs are laid in small caverns underground no doubt, as is the case with the English mole-cricket. It would be an effectual method of dealing with the pest to have every hole traced out and the eggs discovered and destroyed at the breeding season. The female gene- rally keeps watch at the mouth of the tunnel leading to the eggs, and the larvae very possibly take more than one season to reach maturity. It is most desirable that we should obtain full particulars of the life history of the Indian cricket, in order to be able to suggest methods of treatment. ;BI T C H K E ET. A Wire Useful. Traps. Desirable to Know Breed- ing Season. Destroy the Eggs. 264 Report of Investigations in Assam Hemiptera (Capsidae). CHAPTER XIII. HEMIPTERA OR RHYNCHOTA. LX1V. Tea-Mosquito, Green-fly, Aphides, Plant-Lice, Scale- Insects, Plant-Bugs, etc. 511. Under this Order I propose to deal with the HOMOPTERA and HETEROPTERA of Entomologists, without making more than a popular distinction between these sub-orders. Some of the most serious tea pests fall within this assemblage, namely, the Mosquito, Green-fly, Tea Aphis, and Scale-insects. The term " Bug " has at different times been applied by planters, to almost every member of the Order, though the true plant-bugs constitute the HETEROPTERA only, a com- paratively small group of the entire assemblage. Family CAPSID^E. 65. (a) Helopeltis theivora, Water house. The TEA MOSQUITO originally called "BLIGHT," and subse- quently the " TEA-BUG." References. Report, Commissioners appointed to enquire into State and Prospects of Tea Cultivation in Assam, Cachar and Sylhet, 1868, p. 3; Peal in "Englishman," i8thSe.pt. 1872; 2oth March 1873; I2tn Sept- i873 l Journ. Agri.-Horti. Soc. Ind., n. s., Vol. I., Proc., Jan. soth t 1869 {Blight in Cachar), p. vii; Vol. III., p. 221 , Vol. IV. i Peal, the Tea-Bug of Assam, pp. 126-132, -with coloured plates; Proc., 27th Feb. 1873, p. vii ; Proc., 2otfi Nov. 1873, pp. xh-xlvii; Vol V., Dr. C. Aleyboom, " Roest " (Rust) on Tea Plant, pp. 55-61 ; Proc., isth April 1874, PP- xvii-xix ; Proc., 251/1 June 1874, pp. xxvii-xxix ; Proc., joth July 1874, P- xxxvii ; Proc., Aug. 27th, 1874 pp. xlvxhi ; Proc., 24th Aug. i8?6,p.xxvi; Vol. VI., Proc., i8ih Dec. 1879, P- xli; 2*nd July 1880, p. xxi ; Vol. VIL, Proc., 28th Oct. 1885, p. clxxxv ; Proc., soth Dec. 1885, p. cxcv ; Vol. IX., 24th Nov. i8gs,pp. cdvii-cdx , Tea Cyclopaedia, Pl>- 36, 37, 46, 47-49, 50-54; Stoker, Notes on the Manage- ment of Tea in Cachar (1874), p. *9'' Money, Tea Cultivation, fourth edition, July 1883; (Also original Prize Essay, Agri.- Horticultural Soc. Journ., Vol. III., 1871, p. 221); Baildon, Tea in Assam (1877), p. 45: Official Correspondence on the Deputation of Wood-Mason to Assam, 1880-1881 ; Wood-Mason, Report on Tea-Bug in Assam (1884), pp. 12-20 , Tea Planter's Vade Mecum (1885), Tea-Bug., pp. 100-102, Mosquito 103-104 ; Notes on Tea in Darjeeling (1888), p. 51 Green, Insect Pests of the Tea (1890), pp. 71-81 ; E. T. Atkinson ( ? 1890 ) (Rhynchota) in Indian Museum Notes, Vol. I., (pt. 4), pp. 175-186, plate XII. ; L. de Niceville, I. c. pp. 197-198; Bamber, Chem. fef Agri. of Tea (1803), pp. 245-248, Ind.. Mus. Notes, Vol. II., pp. 43, 166 ; Vol. IV., p. 42 ; G. C. Dudgeon Tea Pests and Blights. 265 The Tea Mosquito. in Indian Mus. Notes, Vol. III., (ft. 5), pp. 33-38; Miles, Bulletin Micro. Soc., Calcutta, Vol. IV., July 1895, PP- 4~44 : Christison, Home & Colonial Mail, ist Jan. 1897; Crole,Tea Text-Book, pp. 82, 223. (Reg. No. i, tubes (red form) Nos. 6, 135, 164, 229, 231, 237, 244, (green furm) 126, 182, 220.) History. 512, First Mention of Blight The facts regarding the appear- ance of this, the most alarming of all Indian tea pests, may be said to be fully indicated by the above citation of papers, reports and letters, that have appeared. It seems to have been first noticed in Cachar about 1865. The Report of the Commissioners appointed by Government to enquire into the state and prospects of Tea Cultivation, informs us that "heavy losses from blight in 1865 and again in 1867 " had been sustained. " It is said to show itself in the end of June or July, and to continue more or less to the close of the season. The circumstances of its appearance and progress have not been noted with the accuracy necessary to enable us to form any opinion of its nature." " The loss from this cause in the gardens of one company in 1867 was estimated as high as 50,000 Ibs. of Tea. It is a singular fact that blight is almost, if not entirely, confined to that part of Cachar which lies to the south of the Barak River." 513. Early Allusion to it in Darjeeling. The next historic incident to which attention may be drawn, is a correspondence given in the Proceedings of the Agri.-Horticultural Society of India, for the zoth January 1869. Dr. Thomas Anderson (Superintendent, Royal Botanic Gardens, Calcutta) sent certain samples to the late Rev. Mr. Berkeley. These consisted of specimens furnished by the late Mr. 8. E. Peal, of Assam, under the name of "Black Smut or Rust," and another set by Messrs. Jardine, Skinner & Co., from one of their Cachar gardens. Regarding the latter Mr. Berkeley said, he could find no fungus, but the former, he thought, might be a species of Asterina. In submitting this report to the Agri.-Horticultural Society, Dr. T. Anderson remarked that since he had sent the samples to Mr. Berkeley he had himself observed the disease called " Blight " by Cachar plan- ters on some tea plants at Darjeeling. " He had carefully examined the bushes and could find no diseased leaves in any other stage of the disease, but that forwarded to Mr. Berkeley. He, however, found several leaves with a small insect lying under the epidermis of TEA MOSQUITO : HISTORY. First Recorded South of BaraKRiver Early Mistakes. Cachar Blight not Fungoid. 266 Report of Investigations in Assam Rhynchota (Capsidae). HISTORY. Found In " Mresa. Con/, with para. 1O. First Suggestion o Insect Origin A BHght Peculiar to Caehar. the leaf, and he supposed that this insect must have devoured the parenchyma, and caused the transparent spots ( blight ) with which the leaf was covered. Dr. Anderson exhibited some of these leaves with the insect in position ; also a few leaves with minute eggs of an insect, collected in patches on the surface of the leaf. Dr. Anderson said that he found many of the indigenous plants in the forests, adjoining those tea estates in which blight had been observed, were also affected. He particularly noticed Gordonia Wallichii,* a Ternstrcemiaceous plant nearly allied to tea, a Polygonum, an Osbeckia and Maesa montana as suffering much from the blight. Dr. Anderson shewed young leaves of Cinchona succirubra from a tea estate at Darjeeling ; these leaves were covered with the blight spots." 514. I have given the above passage in full, as I think it is of great historic value. Dr. Anderson was the first observer to suggest that the blight was in all probability caused by an insect. He made a mistake, however, in associating a leaf-mining insect (possibly Oscinis these) with it, so in a like manner the " patches of eggs " that he discovered were very possibly the male scales of Chionaspis these. A similar mistake, no doubt, had been made in sending to Mr. Berkeley leaves with "black smut" as it was called, since these leaves in all probability contained one of the numerous species of COCCID^E with its associated fungus, but which had nothing in that case to do with mosquito. There remains, however, as I take it, the unmis- takable fact that Dr. Anderson found in Darjeeling mosquito punc- turings on Tea and Cinchona as early as 1869. It is also significant that he should have drawn attention to the very similar puncturings that we know are caused by allied insects, on Maesa and Polygo- num. But Schima Wallichii has only once, since the date of Dr. Anderson's observations, been recorded as being so punctured, namely, by Mr. C. N. Harcourt, Ind. Mus. Notes, Vol. II., (pt, I), p- 43. Schima is a closely allied plant to the tea, and it is, there- fore, just possible that all subsequent observers have made a mistake in not giving this subject more careful study. 515. The next fact in historic sequence is Colonel Money's refer- ence to " blight " in his Prize Essay published originally in 1871. He there tells us : " Blight (a serious matter I hear in Caehar) I know * Schima Wallichii, Choisy, as it is now called. Tea Pests and Blights. 267 The Tea Mosquito. but little of. I do not remember hearing anything about it, when I was there, now six years ago. " The date thus given for the appearance of the pest corresponds with that already mentioned, namely, 1865. The volumes of the Agri.-Horticultural Society of India from 1872-1877 may be said to literally teem with papers and letters from planters and others on the subject. 516. Identification of Insect. To Mr. 8. E. Peal belongs both the credit of having awakened interest in this insect and of having himself written perhaps the best account of the methods of depredation effected by it, that exists even to the present day. " The Tea-Bug of Assam" with seven coloured plates, will be found in the fourth volume of the Agri.-Horticultural Society's Journal. Ten years later Mr. d. Wood-Mason paid Mr. Peal the compliment of saying that, in his opinion, the Society " did not spend as much money as the beauty of the drawings and the importance of the subject demanded. " Mr. Peal did not give the insect its scientific name, and he did not discover its method of depositing its eggs on the tea shoots, but in every other respect his paper contains very nearly all that we at present know of a practical nature regarding the pest. Shortly after the appearance of Mr. Peal's paper, Dr. C. Aleyboom, of Java, contributed to the Agri.-Horticultural Society a translation of an article he had written " a few years ago, " in which it would appear, after testing every aspect of the disease that seemed to suggest a fungoid origin, he had arrived at the same conclusion as Mr. Peal, namely, that it was caused by an insect, though he neither named nor described it. 517. Mr. Peal, in the same journal, published a letter in reply to some of Dr. Aleyboom's observations. He also furnished samples of the insect, and these were forwarded to England for the inspection of Entomological experts. A copy of Mr. Peal's letter to the {Englishman, i8th September 1872) was forwarded to Mr. Grote along with the specimens, and these were ultimately submitted to Mr. F. Moore. In the Proceedings of the Society for 2oth November 1873, Mr. Melville Pike, of Serispur Tea Factory, Hylakandy, Cachar, is stated to have forwarded samples of the mosquito. These were accom- panied with a most instructive letter that gives many useful details ; amongst others, he says that the insects are amber- coloured, but be- come green on their being distended with the sap. He then proceeds MOSQUITO : HISTORY, Discovery in Assam. Discovery in Java. Insect named Mr. Moore. Become Green after Feeding. Con/, wit para. S73 (P. 1991). 268 Report of Investigations in Assam Hemiptera (Capsidae). HELOPELTIS THEIVORA: HISTORY. Professor Westwood's Paper. Rediscovered in Darjeeling. Scientific Investiga- tions. to give particulars of the time taken for the insect to reach maturity and the number of punctures a full-grown insect is capable of inflict- ing per day. 518. Mr. Crete's reply as to the name of the insect furnished by Mr. Peal (Proc., i$th April 1874) informed the Society that Mr. Moore had identified it as a species of HELOPELTIS (a genus of CAPSID.&) of which four species as yet are known, one from Ceylon and two from the Indian Archipelago. The Assam form is thus the fourth, and it much resembles that from New Guinea. From its feeding on the juice of the tea plant Mr. Moore adds" I have named it Helopeltis theivora." 519. In the Proceedings for 251*1 June 1874, further particulars regarding the insect are given. Samples had been submitted to Professor Westwood who wrote a paper on it, the only additional point of historic interest being the fact that the Java mosquito had been examined and named in 1871. In 1874 Mr. Peal, who had been asked for a further supply of specimens, reported that " curiously enough the bug is not here this year, the early and unexceptionally heavy wet may have something to do with it." Later on, 27th August, he again wrote, " I now find I was rather premature in this, as they are again causing damage. This year they seem to have shewn later than usual." 520. One of the earliest direct reports on mosquito in Darjeeling District will be found in a letter from Messrs. Lloyd & Co., Agents for the Chenga Tea Company, 28th October 1885. 521. Scientific Investigations Required. This leads naturally to the period of the official correspondence regarding the late Mr. J, Wood-Mason's deputation to Cachar, in order to study the " tea-bug, " and to suggest the best means for destroying the pest. Mr. J. Wood- Mason' 8 explorations to ok place from March to November 1881, and his Report on the Tea-Mite and the Tea-Bug of A ssam* appeared in 1884. Some of the particulars, regarding which it was desired to obtain in- formation, as set forth in the correspondence, may be here usefully abstracted from these official papers. In their letter to the Govern- ment of India, the Calcutta Tea Agents asked for the services of both * It would have been more correct had this been called The Tea-Bug of Cachar, since apparently Mr. Wood-Mason did not visit Assam proper. Tea Pests and Blights. 269 The Tea Mosquito. a botanist and an entomologist. They stated that information wa desired on the following points : is/. The nature of the insect. 2nd. Its manner of propagation. 3rd. Its time of propagation. 4th. Its place of propagation. $th. The stages of its existence. 6th. The stage in which most easily destroyed. "jth. The most effectual modes of its destruction. 8th. Whether modes of pruning, plucking and cultivating the bushes, etc., are not at fault, and what changes in these directions would be likely to have a beneficia effect. 522. It seems somewhat unfortunate that it did not occur to Mr Wood-Mason that it would be desirable to attempt to trace out the history of the pest. He does not mention the gardens where he found it, nor those in which he did not find it. He makes no refer- ence to the annual date of appearance and disappearance. He disposes in a few words of the suggestion of its possible association with parti- cular soils, with shade, or with methods of cultivation. These, he says, are not singly nor collectively causes of the disease. He dis- . covered its method of depositing its eggs on the young shoots a practical fact of great importance but he does not venture on a sug- gestion even, as to its method of hibernation the period when in all probability it could be most easily assailed. In the official corre- spondence prior to his deputation to Cachar, Mr. J. Wood- Mason laid before the Government of India a paper of Professor Ray Lan kester's (which had appeared in Nature) on the subject of the possi- bility of attacking the insect pests of crops, by communicating to them the spores of destructive (parasitic) fungi. But in the report of his investigations Mr. Wood -Mason makes no further allusion to this subject, nor to his having discovered any of the natural enemies of the mosquito. 523. Discovery of Insect in Ceylon. The next paper on mos- quito that need be here mentioned is one by the late Dr. Trimen (Nature, Vol. XXX., (1884), p. 634) which gives particulars of the depreda- tions on Cacao and Cinchona of H. antonii. This may be said to TEA MOSQUITO : HISTORY. Subjects of Information still Desired. Con/, with para. 338, 555. Discovery of the Ovipositor. Con/, with para. 536. Natural Enemies. Cow/, tvith paras. 542, 566-11. Discovery Mosquito in Ceylon. 270 Report of Investigations in Assam Rhynchota (Capsidas). HELOPELTIS THEIVORA HISTORY. Various Species of Helopeltis. Possible Natural Con/, with para. 566. Method of Depositing Green Colour of Abdomen. Hairs on the Legs and have been followed by Mr. E. E. Green's most excellent account of the appearance of that insect on tea in Ceylon. 524. The Species of Helopeltis. The late Mr. E. T. Atkinson (Ind. Mus. Notes, Vol. 7. (pt. 4), 175-186 ) published a review of the known species of Helopeltis, some ten in number; one, the Ceylon insect, H. antonii already mentioned, two found in India, viz., H. theivora and H. febriculosa, and the remainder in Java, New Guinea and the Philippines. One of the most interesting side issues of Mr. Atkinson's paper may be said to be the mention of a possible natural enemy to the mosquito, a REDUVIID that had been discovered by Mr. W. L Distant among some Ceylon samples of H. antonii. The plate furnished by Mr. Atkinson gives illustrations of four of the species of Helopeltis, the figures of H. theivora being exception- ally beautiful and accurate. 525. More Recent Investigations. Perhaps the next Indian papers of importance are those by Mr. C. N. Harcourt (Ind. Mus. Notes, Vol. II., 43) and by Mr. G. C. Dudgeon (Ind. Mus. Notes, Vol. III., (pt. 5), pp. 33-38}. Both these writers deal with the method of depositing eggs on the young shoots. But Mr. Dudgeon adds several interesting additional details. A point of special value may be here alluded to, in Mr. Dudgeon's paper, viz., where he tells us that the abdomen, in fresh specimens of both sexes, is invariably bright emerald green, marked dorsally, on the third to ninth seg- ments, with shiny dark brown. So again, he continues, the larvae are greenish with deep ochreous or orange legs and antennae. He further discusses the question of the puncturings, similar to those on tea, that are to be seen on jungle plants, such as on Maesa indica, and adds that, so far, none of these have proved to be caused by Helopeltis theivora. 526. Lastly, Mr. Cotes' account of this insect, in Insects and Mites of ike Tea Plant in India (pp. 29-33}, mav be characterised as a useful review of the literature of this pest, but one which furnishes no addi- tional information. It may further be pointed out that the insect as figured by Mr. Cotes differs in certain respects from Mr. Atkinson's most excellent plate, for example, both the legs and antennae are shown by Mr. Cotes as very hairy, while they are quite glabrous in the drawings furnished by Mr. Atkinson. The object I have in directing attention to these particulars may be at once stated, viz., that I suspect Tea Pests and Blights. 271 The Tea Mosquito. there are two forms of mosquito met with in Indian tea gardens, and that the drawings mentioned practically represent these. 527. Conclusions. To conclude this brief historic review of the early literature of the subject, it may be said that it is significant that a form of the so-called tea mosquito should have simultaneously ap- peared in Cachar and Assam, namely, from 1865 to 1868. If we can accept Dr. T. Anderson's observations as pointing to mosquito, then the insect would seem to have appeared about the same period in Darjeeling. We next hear of it in Java and subsequently in Ceylon. Description. 528. Explorations in Assam. During my explorations in Assam, I came across the mosquito here and there all over the province. It appeared, disappeared and re-appeared in the most perplexing manner. One garden would be found practically stopped through this pest, while a few miles off another garden could hardly be said to have any mosquitos. In every garden where it was found to an injurious extent, women and children were employed to collect the insects. At the end of the day's operations the collectors returned and an estimate was made of the sum due to each. For several weeks on end I must have seen and examined many thousand mosquitos almost daily. They were all of a bright orange-red colour, almost pink in the very young larval stage, but deepening with age, the males becoming almost black in general colour. Mr. Peal's plates are, if anything, too yellow for the insect as seen by me; Mr. Wood-Mason gives no description of the insect he investigated in Cachar. 529. Green Colour of Mosquito. Prior to my visit to Assam I had read the passages alluded to above, where the mosquito is said to turn green on its absorbing the tea sap. As I had failed to find any examples of that colour, I was surprised and mentioned the fact to Mr. Peal. He at once said it was a mistake, that the colour deepens with age, but does not change on its sucking the tea juice. To make quite sure I had some insects placed on a tea bush enclosed with mosquito-curtain cloth, and watched them puncture the leaves, saw the brown spots gradually form on these, but never witnessed any change of colour in the insect itself before nor after its meal. I never came across a green mosquito in any of the gardens of Sib- sagar or Dibrugarh. But on this very point of the colour of the TEA MOSQUITO : DESCRIP- TION. Distribution in Assam. Orange Red Colour. Green Colour of Mosquito. Con/, with para. 517, 525, 573 (p. 291). Report of Investigations in Assam Hemiptera (Capsidse). HELOPELTIS JBRICU- LOSA: ;RIP- Green-fly. Conf, with paras. 577, 679. NORTH BANK MOSQUITO. Naked Shining Red Form. Hairy Green Insect. insect Mr. Peal seems to have unconsciously changed his opinion without the suggestion having apparently occurred to his mind that there might be two species. Shortly after the appearance of Mr. Peal's original paper, a tea planter wrote in The Tea Gazette, "As to the description of the insect, on the whole I think Mr. Peal is very correct, but on a few points I think he errs ; thus, for instance, he says that, when very young, it is ' of a pale green colour ' ; now I have examined many thousand specimens, and I have never found one of that colour yet : they are even from the very earliest stage, when little larger than the red-spider, of a brownish-red colour, and never, during any stage of their existence, become of a green colour. From the great similarity in appearance, otherwise between the young of the mosquito pest and the tea aphis, I am inclined to think Mr. Peal must have confused the two." In this connection it may be remarked, Mr. Peal certainly did make a mistake in calling green-fly an aphis. 530. North Bank Mosquito, But I was greatly surprised on my crossing to North Lakhimpur (that is to say, to the gardens on the north bank of the Brahmaputra) to find the young insects of a pale emerald colour, and yellowish green with faint brown markings in the adult condition. At Patalipam, visited in July 1895, * coul d not find an orange-red mosquito on the tea, though I was told a red insect was occasionally met with. This led me to compare my collections of red mosquito with the live green ones. They differed in several respects. The orange-red insect, in its mature state, was seen to be larger than the straw-coloured form. It was observed to be very nearly glabrous (that is to say, had few, if any, hairs on the body, legs, or antennge), and the abdomen was of a bright shining dark orange-red with black bands on the five terminal segments. These bands, at least the last three, could hardly be called dorsal, however, since they were seen to be nearly as deep in colour on the belly as on the back of the segments. The green and straw-coloured insect, on the other hand, was noted to be considerably smaller and very much more hairy, than the red form, especially on the lower portions of the legs, and on the antennae, while the drumstick-like spine on the scutellum was observed to be almost bristly, both on the shaft and on the knob. A pale-coloured Tea Pests and Blights. 273 The Tea Mosquito. lateral line was also noted as extending across the dark dorsal bands the last three segments, and the belly was pale straw-coloured. Th males seem to turn quite black and the wings to become near twice the length of the body. 531. These characters may not of course suffice to justify the separation as two species, but I still further observed that the effec on the plant, of the puncturings of the green insect, were very diffe ent from those of the red. Whether, therefore, they be regarded i varieties or species, the isolation of the two forms seems to me worth of consideration. 532. It was accordingly with no small interest that I examined th type samples preserved in the Indian Museum. The first serie that attracted my attention consisted of samples sent from Darjeelin by Sir G. King as having been found on the Cinchona. These wer undoubtedly identical with my North bank Assam insect. Mr. Atkin son tells us that certain samples of mosquito collected by Mr. Gammi at the Mungphu Cinchona plantations, had arrived at the Museum, an that he had sent these to Dr. Bergroth for identification. The insec in question had proved to be Helopeltis febriculosa, Bergroth The description of that species answers very nearly to my Nortl bank Assam insect. The tibise are spoken of as clothed with sligh somewhat hispid hairs ; the abdomen is said to be sub-virescent and the rostrum sparingly thinly pilose, etc. 533. Whether the whole of the mosquitos of the Darjeeling tea districts should, from the circumstances narrated, be assumed to be H. febriculosa may be open to some doubt, but, it will be observed, Mr. Dudgeon speaks of the abdomen as being bright emerald green. The point is worthy of further enquiry since it is certainly significant that the green insect should be practically un- known in the gardens of the South bank of Assam, while it is fairly abundant on those to the North. 534. But I must hasten to add that the other day (July 1897), I asked the superintendent of Patalipam to kindly furnish me with a fresh supply of the green mosquito I had found there in 1895. His reply is most instructive. The green insect had been getting more and more scarce every year, and the red one taking its place. He furnished me with samples, and quite half were the red sub-glabrous insect with black or rather brown-black terminal abdominal segments. 18 TEA MOSQUITO : DESCRIPTION. Effect on Plant. Darjeeling insect. atalipam Mosquito. Report of Investigations in Assam Rhynchota (Capsidae). HELOPELTIS THEIVORA : T E , N O EA - N HIBERN TION. The Ovipositor. Con/, with para. 522. Bristles of tde Egg. It may, therefore, I think, be suggested that the green insect was the one that first appeared, and that the story of its turning green on its having had a meal arose from the two forms being confused one with the other. Annual Generations and Period of Hibernation. 535. I regret to say that the shortness of my explorations in Assam prevented me from instituting any very practical investigations into these all-important points in the life history of the mosquito. It may, however, be useful if I bring together all the facts that have been ascertained. Mr. Melville Pike gave (1873) the following particulars : " The insect on growing older and increasing in size assumes a deeper amber or orange colour : after moulting their skins, the antennse get longer and turn to a black colour, is less active in moving or flying about in its perfect state, and is provided with wings of a dark (ap- proaching to black) colour." 536. Discover y of tte Ovipositor. -The most important part of Mr. Wood-Mason's investigations was doubtless the discovery of the method and place of deposit of the eggs. After giving a passage from Mr. Peal's report, descriptive of the course of depredation, he continues : " It was reserved for me to discover the manner and position in which the tea-bug lays its eggs ; and a brief but sufficient account of my observations is given in the following communication addressed by me on June 8th, 1881, to the Chief Commissioner of Assam, by whose orders it was published in the Assam Gazette, for general information : 537- " Tea-Bug. Have discovered, by observation of specimens of this formidable pest kept in confinement, that the female deposits her eggs singly in the substance of the tenderest shoots of the plant, in the internodes or portions of the stem between the pekoe and the two or three leaves succeeding from above downwards, and in the buds deve- loped in the axils of plucked leaves and in the parts thereabout ; that the presence and position of each egg is from the first indicated on the exterior by two unequally long, glistening white, bristle-like prolonga- tions of its shell, and later by discoloration of the point pierced. Have discovered by dissection that she is provided with a serrated oviposi- tor, of the shape and sharpness of a sabre, wherewith to pierce holes in the soft tissues of the plant for the reception of her eggs. These Tea Pests and Blights. 375 The Tea Mosquito. observations have been verified in the field upon numerous blighted bushes ; but, though eggs have readily been found by the unaided eye on blighted portions of bushes, not a single one has yet been seen on any perfectly uninjured shoot. The vigorous and unremitting pluck- ing of the blighted portions of bushes might mitigate the evil ;* and I would suggest that this message be sent to newspapers and pub- lished in the Gazette for general information." 538. " The agents and owners of tea-estates had always attached the greatest importance to the discovery of the eggs, as they hoped by the destruction of these to effect the extermination of the pest, or at least a diminution of its numbers ; and with the view of assisting the planters in finding out in what part of the plant the eggs were deposited, long before I visited Assam I had suggested that eggs or viviparously produced young should be sought on the young and tender shoots. Some time before my mission was arranged, I received from Mr. Alexander Wilson several microscopic slides, which, that gentleman informed me, were supposed to contain viviparously pro- duced young taken from young shoots by one of his employes, who, I think it was stated, had actually witnessed their birth on the shoots." 539. " These slides proved on examination to contain ripe eggs which had evidently been taken from the bodies of females and not from the plants at all the prepaier of them having evidently mistaken the two unequal processes which spring from the mouth of each egg for antennse, and hence jumped to the conclusion that he had found fully formed embryos ready to be deposited alive upon the bushes Though I never succeeded in finding embryos in eggs extracted from the bodies of females, it is possible, but highly improbable, that under certain circumstances such may occur, that eggs may be retained by the females until development is far advanced, and be inserted in this condition in the usual manner into the substance of young shoots just as undeveloped eggs are." 540. " The knobbed ends and also the sides of the two tubular processes of the mouth of the egg-shell, to a greater or less extent, ar< studded with button-shaped elevations, each of which has a minute pi in its centre. These pits are probably the ends of minute tubules which place the lumens of 'the processes in direct communication with the exterior, and thus serve to carry air to the developing ovum. The TEA MOSQUITO : GENERA- TIONS and HIBERNA- TION. Mscovery of the Egg. Con/, with para. 521. Viviparous Reproduc- tion. 18 A Conf. -with paras. 543, 545, 560-1. Tubular Processes of the Egg. 2 7 6 Report of Investigations in Assam Hemiptera (Capsidae). HELOPELTIS THEIVORA: GENERA- TIONS and HIBERNA- TION. Eggs not Deposited on Punctured Shoots. IP Of Spider Attacking Mosquito. Con/, ivith paras. 522, S66, 670. Formation Wings. Position of Eggs. Con/, with paras. 537. 645, 660-1: eggs are provided with deep saucer-shaped lids, perforated, sieve-like, with holes which are large enough to admit the spermatozoa." 541. " In order that the reader may form some idea of the numbers of the eggs, I may state that, on one occasion I counted more than forty eggs in twelve shoots taken consecutively and at randum from a plucker's basket ; and that on another occasion I selected and plucked from one bush of a plot of tea, which was only moderately blighted, four shoots with one or more eggs in each. The females appear instinc- tively to avoid puncturing the shoots or the parts of the shoots in which they lay their eggs, for one can rarely find eggs on badly injured shoots." 542. Period Required for Larval Growth. Mr. Harcourt says, " The eggs are laid in the soft stems of the tea shoots, and can only be discovered from the three small hairs which are attached to each egg and which protrude from where it lies. The eggs are about one-thirty- second of an inch in length and very slender. When first laid, they are hard and white in colour, but they become red before hatching. The larva becomes full grown in about a week after emerging from the egg ; and it has the characteristic bug-like odour and the only animal noticed to attack it is a small spider." A writer in the Tea Gazette says, " The rapidity with which the wings are developed is something wonderful :-*-with one specimen which I had imprisoned for about seven days no wings were visible ; then, two little embryo ones like minute quills showed themselves ; and after these had remained about three days, the full four wings were developed apparently at once. Certainly, late one evening no wings were visible, only the little stumps of quills, and in the morning the four wings were fully developed and the insect had changed from brown to black." " While in the larval stage they are all alike, except in regard to size, but when fully developed two different kinds appear one a slim delicate sort of fellow all black, the other with an orange hump between his shoulders and with a dirty white abdomen. The former is the male, and the latter the female." 543. Hibernating Eggs. Mr. Driver, as quoted by Mr. Atkinson, says, " I think the eggs are laid at the points where new shoots spring from the older stems and that they are hatched in March, just about the time the new shoots begin to grow. They go on breeding during the rains, but heavy rain washes them off the bushes and destroys them. These insects are indigenous in Assam, and, while in the jungles, live Tea Pests and Blights. 277 The Tea Mosquito, on a creeper known as the 'jangli pan.'* The jangli pan leaves taste very like the pan of commerce. The insect is called woohonce by the Assamese. These insects thrive best under large shady trees, such as the rubber and wild fig." The above opinion, if confirmed, would point to hibernation being most probably by eggs deposited at the bottom of each shoot. 544. Nature of the Egg and Method of Hatching* Mr. Dudgeon advanced our knowledge of the subject of the deposition of the eggs on the young shoots in several directions. He tells us that two are generally placed together, so that four short stiff threads are seen protruding from the shoot. Each egg, even before being laid, possesses its own pair of these hair-like elongations. Mr. Dudgeon further tells us that, " nine or ten eggs are generally found in the body of a mature female as, owing to their large size in comparison to the insect itself, there would scarcely be room for more. It is possible that more eggs are formed as they are laid." 545. " The eggs are at first pure white, and are generally found in the green stems of tea which have been passed over by the leaf pluckers as being too hard for manufacture. Did the insect content itself with laying in the soft green stems, doubtless it would soon be exterminated on tea gardens, where the leaf is not allowed to run out much. But apparently nature has provided against man, and the eggs are laid in the unpicked slightly hardened stems. (Con/, with paras. JJ7, 560.) Just previous to the larvae emerging the eggs become yellowish, the inner or more spherical end being streaked with orange red (representing the legs and antennae of the larvae)." 546. Mr. Dudgeon also made some interesting observations on the method of escape of larvae from the eggs. They would appear to leave the lower end of the egg and to eat their way through the tissue of the shoot. * In the extract given below from my diary (p. 291) it will be found I asked Mr. Peal about this. At the time I thought that Pea! had said the mosquito lived on the wild pan. He repudiated ever having done so and informed me that (like myself) he had never seen it on the pan. In a letter recently to hand from Mr. P. J. Macdonald, the following occurs : " This same insect is said to commit great havoc on the pAn crop." Could this statement be true of Cachar, though certainly not of Assam ? The point is worthy of careful enquiry, since it is probable the mosquito pest of tea first appeared in Cachar. I looked very carefully during many marches through miles of wild pan, but never saw the slightest indication of mosquito puncturings on that plant. MOSQUITO : and HIBERNA- TION. Pan Leaves. Conf. with para. 1O* Method of Hatching. Eggs laid in Unpicked Stems. Escape of Larvae. Report of Investigations in Assam Rhynchota (Capsidae). HELOPELTIS THEIVORA : GENERA- "JSP Hibernation in Ground. Hibernation in Water. 547. Hibernation in a Larval or Imaginal Condition and within the Ground. In another part of his paper Mr. Dudgeon alludes to the question of hibernation. " Although theories and ex- planations have been given," he says, " by many on this point, I have never heard of one which was not based on supposition and occasion- ally most absurd ones. One which is most generally believed is, that the insect retires to the jungles in the cold season to feed on other plants, when the pruners have removed from the tea bushes all the leaves and stalks that were soft, leaving it nothing there to subsist on." " My own theory regarding mosquito blight in the cold weather is, that it hibernates in a semi-dormant state near the root of the tea plant,* either in the larval or imaginal stage, and, that, as in the case of many other insects, it does not require nourishment during this period. As soon as the weather commences to get warm, its vigour returns, and it commences feeding on the young shoots and is propa- gated throughout the year, being observed in Darjeeling to be worst about September and October. This seems natural, as, during each successive brood, the individuals multiply until the cold weather comes, which, without doubt, kills off many, and others, in their sup- posed dormant state, fall easy victims to their persecutors, leaving a scattered minority to reproduce their species in the Spring. These conjectures I have not however been able to verify yet." In a letter received from Mr. P. J. Macdonald a remark occurs that may possibly be regarded as pointing to hibernation in the ground. " The blight," writes Mr. Macdonald, " shows a decided pre- dilection for the same feeding ground year after year, and, without any apparent cause, will avoid portions of a garden which are identi- cally similar to those annually visited." 548. Hibernation in Water. The suggestion has been often made, very possibly from a mistaken idea, that this pest was an actual mosquito, that it hibernates in water. It would serve no very useful purpose to give a review of the repeated occasions on which this statement has been made. As expressive of all, I may give the follow- ing : " I believe the blight hibernates in water or swampy ground. Tea in the neighbourhood of such surroundings is invariably first attacked. " It cannot of course be said hibernation in water is im- possible, though I should think highly improbable. * See the concluding remarks, para. 561. Tea Pests and Blights. 279 The Tea Mosquito. 549- Hibernation on the Bamboo, on TunTrees, etc., etc. A very large number of planters believe that the insect hibernates on the bamboo. No one has, however, either observed the hiber- nation or seen the bamboo leaves punctured in a manner similar to the tea. The opinion seems to have originated from the prevalence of bamboo in the jungles of Assam, when taken in conjunction with the observation that mosquito blight very often commences on the jungle end of an estate, or in out-gardens surrounded by jungle. But, on the other hand, there might of course be an allied insect to HelO- peltis theivora found on the Tun, so that until the tea mosquito has been actually collected and named by an entomologist from the Tun, all such reports, as the above, must be disregarded. In the extracts from my diary, given below (/>. 291), it will be seen that Mr. llbert (Moran Tea Company, Sibsagar) had observed that the mosquito developed under the shade of trees, and that Ficus and Cedrela (tun) are the shade trees which it more especially favours. Mr. llbert had never seen the mosquito feeding on any jungle plant, though on one occasion, to his certain knowledge, it attacked a few Hibiscus plants in his flower garden. 550. The above abstract gives, so far as I am aware, all the parti- culars of the life of the mosquito that have as yet been learned. It is supposed that the insect takes about a week to reach maturity from the time of its escaping from the egg. If that be actually the case the number of generations must be very great during the year. But how long does it live in the mature state, and how many eggs does each female lay ? Surely, with a question of such vast importance, the remark may be pardoned that it is surprising that the planters have not themselves removed all doubt on the numerous obscure points in the life of this terrible pest. No rational effort can be made, towards a cure, until we are possessed of full particulars, and there should be little difficulty in obtaining these particulars. 551. My own inferences as to hibernation, point very much in the direction indicated by Mr. Dudgeon. In the extracts from my diary of observations, which will be found below (pp. 293-4), ^ w^ be observed that on several occasions gardens have been freed absolutely from this pest by having been fired. Such examples would point to hibernation being either in the ground around the tea bush, or on the bush itself. The passage quoted above from a paper by Mr. Drive MOSQUITO j GENERA. 1IONS and HIBERNA- TION. Shade Tree. Annual Generations. Firing of Gardens. 280 Report of Investigations in Assam Hemiptera (Capsidse). HELOPELTIS THEIVORA DEPREDA- TIONS. Red Mosquito. Green Mosquito. (/. 576) would necessitate hibernation being in the condition of an egg deposited at the base of the Spring shoot the portion that would be left in light pruning. Mr. E. E. Green informs me that in Ceylon the " eggs are very frequently deposited in the internodes between the bud-scale and the first leaf. It is this fact that allows so many of them to escape destruction in the ordinary course of plucking," That is a point worthy of careful investigation, but it would seem probable that ultimate hibernation may be in the condition suggested by Mr. Dudgeon. Depreciations. 552. Appearance of Bushes with Red Mosquito. It would seem hardly necessary that I should attempt to detail the appearance of bushes blighted by mosquito after the very accurate account given by Mr Peal and several subsequent writers. In India the mosquito operates on the upper surface of the leaf, but, according to Dr. Aleyboom, the form met with in Java punctures the under surface. The insect both in its larval and mature condition inserts its proboscis through the epidermis of the leaf or shoot, and sucks the juice. A discoloration occurs over the area of depletion, and it becomes pale brown. A small speck may be seen in the centre of the spot, mark- ing the actual puncture and the circumference of the space is indi- cated by a slightly darkened rim. In time this deepens in colour and dries up until it becomes a black and dead space of, perhaps, |th to f th of an inch in diameter. If the puncturings are made by very young larvae, they are said to be more numerous and to coalesce into irregular patches. The adult moves from place to place and may puncture the same leaf a dozen times, so that, on these spots becom- ing discoloured, the whole leaf turns black and shrivels up. It is unfortunately the young shoots, the tea-making " two and a bud " or " three and a bud " portions, that the mosquito alone attacks, so that, when badly affected, the operations of a garden may be en- tirely interrupted and the bushes become black as if scorched by fire. The terminal buds being thus killed, the laterals spring forth and are in their turn punctured and killed, and for a time a rapid flushing occurs and a desperate effort made by the plant, without the planter being able to get more than a tithe of the shoots that he had anticipated. 553. Action of Green Mosquito. That is briefly the story of the ravages of the red mosquito. It will best, perhaps, fulfil my Tea Pests and Blights. 281 The Tea Mosquito. purpose if I now give a passage from my diary, descriptive of th depredations of the green mosquito : As already explained, the larvae are pale green, not red, and the manner of attacking the tea seems different from that of the insec met with on the South bank. The Patalipam insect first attacks a the lower lateral young buds which, when punctured, are killed. Th leaves on the main shoot are also punctured, but not so profusely a with the red insect. The result of this is that the leaves remain o the shoot, become contorted and twisted, but still keep thei green colour. The punctures become actual perforations througi the tissue, not mere discolorations. Ultimately the main bud ma be punctured, in which case the shoot stops growing. A bud righ down at the redwood has accordingly to take its place, instead o the lateral buds which renew the completely killed and blackene central axis of the shoot, with the South bank insect. In other words the mosquito of the South bank (which has red, not green, larvae attacks the main bud and the new leaves around it first, so that the flushing shoot becomes at once deflexed and turns black. When the terminal bud is punctured by the Patalipam insect, the whole shoot is killed and the pith will then be seen to be black within the still green shoot. 554- Choice of Jats. Mr. Wood- Mason tells us that in his day the mosquito preferred the China plant, the indigenous enjoying "an almost complete immunity from attack." He goes into details in justi- fication of this fact, by alluding to previously recorded instances where pests have shown favour for certain forms of a plant and have left alone others of the same species. Unfortunately this immunity of the indigenous plant cannot be said to continue to the present day. It is true, however, that mosquito very often commences operations in a garden, by attacking the China or hybrid bushes first, but it soon extends to the finer jats and may be said by mid season to take all kinds alike. It would almost seem, however, that certain tracts of country (such as the Tezpur District) that comprise a large percentage of comparatively new gardens or that have few, if any, gardens with low jat bushes, feel the effect of mosquito very much less than districts with many old gardens and a high percent- age of inferior jat tea plants. As showing the extent to which the opinion still prevails that the indigenous jats escape the blight, I may TEA MOSQUITO : DEPREDA- TIONS. Lateral Buds First Killed. Choice of Jats. hina Plant. Inferior Hybrids. 282 Report of Investigations in Assam Rhynchota (Capsidae). HELOPELTIS THEIVORA : REMEDY. Physical Influences. Cow/, with paras. 321-2, Distribution. Local Circum- stances. Provincial Circum- stances. See Distribution of Red Rust. Con/, with para. 832. quote the following passage from a letter received by me from Mr. P. J. Macdonald : " Gardens of entirely Indigenous Tea are never attacked by blight." That may be the Cachar experience, but it is certainly not the Assam. Remedy. 555. Physical and Geographical Conditions. It has by no means been shown that position, soil, climate, shade, ventilation, methods of cultivation, and surrounding jungle do not exercise singly or collectively an influence on the appearance and distribution of this pest. These and other such topics have been spasmodically discussed in a perfunctory manner without any attempt having been made to tabulate results and conditions with a view to arriving at definite conclusions. This unsatisfactory state of affairs may in a measure have arisen from the early notion that "Blight" was a mysterious visitation due very possibly to influences for the most part beyond control. Prominence was thereby given to considera- tions such as I have named, to the exclusion of the actual cause, namely, that it was an insect, the germs of \vhichhadtobeintroduced, but could not be created by conditions of soil, climate, etc. 556. Appearance and Disappearance. We now know the immediate cause, beyond all question, but, it seems to me, that greater attention must be paid in the future to the external influences named above before we can hope to approach the question of the eradica- tion of mosquito. The appearance of the insect in one garden, its disappearance from another, only a mile or two distant, and its re- appearance in a third, are local circumstances that possibly may be accounted for by external influences that favour the growth of the insect in the one, and are inimical to it in the other. So again there are conditions of a more general and widespread character, such as the gradual disappearances of the pest in the lower portions of the Assam Valley that call for solution. It is prevalent here and there all through the gardens of the South bank, m'z., in Dibrugarh and Sibsagar down to about Nigiriting, where it becomes almost unknown, it disappears very nearly from the gardens of Nowgong, though it re- appears again at Silghat. So in the same way with the North bank, one garden here and another there suffers badly from North Lakhimpur down to about Biswanath and Tezpur, may be said to be quite free from the pest. Where mosquito abounds red rust is practically unknown. Tea Pests and Blights. The Tea Mosquito. These cannot surely be accidental circumstances ; they are more likely to be governed by conditions on the one hand favourable, and on the other unfavourable, to the life of the insect. To be able to contest the ground held by this terrible pest, therefore, we must fully understand such influences and steps should be taken to obtain some- thing more than personal opinions and speculations. I would, there- fore, urge on the Tea Association and all those interested in Tea cultivation the desirability of an annual census being taken for, say, the next five years all over the tea area. 557. As an appendix to this chapter (pp. 297-301), I shall sug- gest some of the more important questions that might be addressed to managers of gardens in tabulating returns for the census, and shall also propose a few experiments of a preliminary nature that might be instituted. Were replies to these to be furnished I feel certain that we should very soon find ourselves making a tangible advance towards the object finally desired, namely, the eradication of the pest. 558. The Collection, of Mosquitos.M present the system pur- sued is to put on all hands to collect the insects and to have these destroyed. Some good no doubt is accomplished, but at most this is but a palliative treatment. When it is recollected that a garden of 500 acres may contain 1,500,000 bushes, and that when badly affected, each bush may have an average of 10 or more mosquitos, some conception is obtained of the very small results likely to be secured by a collection of even 50,000 daily. Still, however, each female destroyed might have meant eight to ten eggs deposited on the plant, consequently the system of sending out the women and children to collect, cannot be regarded as a useless expenditure. But to be of direct value the collection should be energetically pro- secuted on the first appearance of the pest. 559. Insecticides. I have already expressed my opinion on this subject. There are many poisons that no doubt would kill the larvae of mosquito if they could be applied satisfactorily. To a large extent, however, the objection to the use of insecticides, in tea planting, is more one of expediency than utility. The adult insect flies off with the slightest disturbance : the larvae move to the under sides of the leaves or into protecting corners and angles of the branches. It is commonly said they drop to the ground, but I failed to discover this being the case. On the assumption that they do 482 Report of Investigations in Assam Hemiptera (Capsidae). drop to the ground, a system of tarring the stems, with a view to prevent their again crawling up, was recommended, tried, and, I believe, found unavailing as a remedial measure. The rain which falls almost daily at the season when this pest prevails, would wash off and thus prevent insecticides from re- maining on the bushes, so as to kill the insects on their returning to feed. I have had very little experience, however, in the use of insecticides, and require to possess authentic results of compara- tive plots, before I could recommend that the idea should either be abandoned or large sums of money expended in this direction. But let me add, in conclusion, no insecticide should be employed that contains arsenic or any other highly poisonous substance, both because of the danger to the coolies and the risk that would undoubt- edly be run in the tea bushes being killed, as well as their pests. 560. Hard PlucMng as a Remedy,~It will be seen that Mr. Wood-Mason entertained some expectations that his discovery of the location of the egg on the tea bush, might have practical results. (Paras. 537, 543~5i 55 *) Unfortunately the insect deposits, perhaps, more eggs below the plucking point than above. It also lays its eggs on the green shoots left after the plucking has been made, so that heavy plucking can hardly be regarded as a direct cure. There would, however, be no object in leaving shoots fit for plucking or nearly so, on the bushes of a mosquito-infested plot of land. Plucking allows of tea being made, and at the same time removes the food of the insect, while it no doubt destroys a certain proportion of the eggs. Heavy plucking must, therefore, be beneficial, but to be effectual the plucking would have to be followed by light pruning, so as to cut off all the shoots down to the red wood, the portions so removed being carried off and burned. This no doubt would throw the flushing back very greatly, but if a complete check could be simultaneously given all over the garden, the removal of the food of the insect would no doubt help very greatly towards the eradication of the pest. What good is there in the flushing of a garden badly affected with mosquito ? Practically no return can be obtained for months, and the loss may just as'well be produced as a remedial measure as allowed to be brought about by the pest. 561. Destruction of Prunings. So far as I was enabled to ascertain, there would seem reason to think badly affected plots of tea (that perhaps should only have had a light pruning in the winter), Tea Pests and Blights. 285 The Tea Mosquito. were they to be heavy pruned and the prunings burned, a check might be given to a return of the pest. But please observe this recommendation rests alone on the assumption that the insect hiber- nates on the bush and on the youngish wood. We possess no precise evidence in support of heavy pruning and the destruction of the prunings, as steps towards the mitigation of the pest; they can only, therefore, be recommended as doing little harm and possibly much good. Mr. llbert, of Moran in Sibsagar, writes me, "The part most affected is where I had interlined the old tea, and now old and young tea are attacked indiscriminately. I should think the proportion of young bugs to fully developed, would be about 150 to i, which confirms what I told you that the young only appear in large quantities at the beginning of the year, and it looks as if eggs had been hatched on the tea bushes. The part of the garden which was very badly attacked last year, and which I pruned heavily, has not been touched by the mosquito as yet ; where it is most prevalent is on light pruned tea. There is a very little shade in that part of the garden, and there is no jungle near." But, as opposed to the natural inference from such observation, I would mention that Mr. Alexander informed me " he had noticed that gardens that went in for heavy cleaning out, i.e., removing after pruning of all twigs, leaves, etc., from the plants, were more affected the following year with blight than were gardens where that system had not been pursued." This, if general observa- tions be admissible, might be accounted for by the supposition that, treated in the manner indicated, and having no old leaves, shoots, etc., the plants exposed their vital parts to the pest. Moreover, the new leaves and shoots being all killed and the plants having no old leaves, by which to breathe, they would naturally feel the shock of the pest very acutely. But Mr. Alexander's observation would almost point to the insect being an invader, and not one that hibernated on the tea. 562. Firing Estates as a Remedy. It will be seen that one of the writers on mosquito, whose opinions have been reviewed above (Mr. Dudgeon) suspects that hibernation may take place in the ground (see para. 5^7). In the extracts from my diary (given below, p. 294), parti- culars will be found of a garden in which the owner, after trying every measure that could be suggested, to check the wholesale destruction that was being effected by mosquito, decided in 1886 to fire the entire plot. The bushes recovered the shock rapidly, the garden was MOSQUITO : REMEDY. Effect of Pruning. Proportion of Larvae to Mature Insects. Con/, with para. 673. Effect of Heavy Pruning. Does the Insect Fire as Cure. 386 Report of Investigations in Assam Rhynchota (Capsidae). improved, rather than injured, the pest was entirely eradicated and, what is more significant, up to 1895, the date of my visit to the garden, it had not returned. The cure thus seemed complete. Mr. Crole may be spoken of as an over enthusiastic advocate for fire as a cure for mosquito. In his Tea Text-Book he says, " All that can be done to combat it is to burn down, root and branch, on its first appearance, all bushes at all affected by it." At one time it was thought the mosquito might be attracted to light and thereby killed. With that purpose fires were kindled and kept burning at night. This proved a failure, and naturally so since most of the insects of this Order are but little attracted by light. Another experiment tried and abandoned was to carry flaming torches and to insert these here and there within the bushes, not long enough to set fire to the plants, but sufficient time to burn the mosquitos. This also was abandoned almost as soon as proposed, as it was found to do very little good, and was both troublesome and expensive. 563. Liming the Surface But assuming that the resting or hibernating stage, is deposited in the ground, it might be suggested that a liberal top dressing with lime, worked into the soil in the dry state, might have a beneficial result. I should like to see a plot of tea badly affected by mosquito treated as follows : (a) Heavy prune and burn the prunings immediately. (b} White-wash every twig and stem completely, immediately after the pruning. (c) Top dress the surface soil with dry lime and light hoe into the soil at once. It would seem that if the hibernation takes place on the bushes or in the soil, a treatment of that kind would go a long way toward era- dication, while at the same time it would vastly improve the health of the stock and the condition of the soil. Hardly any tea land in Assam could be said to have enough lime for the necessities of tea, and certainly no tea soils have already too much lime, so that the treatment recommended would be useful, even if not effectual, as a cure for mosquito. 564. Selection of Stock. In Chapter IV I have already suggested that the remedy for this, as also other pests, may have to be approached by the study of the protection given thrtmgh certain races of the plant being found to be proof against the pest. It may have been observed Tea Pests and Blights. 287 The Tea Mosquito. from the historic review above, that in 1881 when Mr. Wood- Mason visited Cachar, the indigenous plant enjoyed an almost complete immunity from mosquito. Since then, however, cultivation has either changed the plant in the direction desired by the mosquito, or the mosquito itself has changed, so that it no longer objects to the flavour of the indigenous tea. Mr. Steele, Manager of Shakomato Tea Company, in a communication I have had the pleasure to receive, has suggested that " we should work not so much to destroy the indi- vidual mosquitos as to prevent their appearance by some such means as manuring and changes in cultivation. It is necessary to find out what particular element in the tea sap is liked by the mosquito, and to endeavour to eradicate or adulterate that without prejudice to the character of the tea." 565. I need hardly dwell on this subject further. It is by no means an unusual occurrence to find here and there bushes not attacked by the mosquito, while all the others around are black and every shoot killed. Surely the selection of a mosquito-proof stock would be by no means impossible. So again, such instances, as narrated, in conversation, by Mr. Peal, (p. 291) are not unusual, viz., of certain bushes attacked year after year, when the rest of the garden has escaped the pest, or practically escaped. Examples of that nature point very possibly to a class of bush that should be eradicated as early as possible. The subject of a more careful selection of stock is one with immense potentialities. 566. Encouragement of the Natural Enemies of the Mosquito. I have incidentally alluded above to Mr. W. L. Distant's discovery of a REDUVIID insect which, he thought, might be parasitic on the mosquito, and which he had found mixed up with some samples of mosquito sent him from Ceylon. During my explorations in Assam I came across a REDUVIID which was undoubtedly parasitic on the mosquito of the South bank. This is an insect, perhaps, half as large again as the male mosquito, has its legs mottled orange and brown, also very hairy. The thorax is of a brown tint, and the abdomen orange coloured. It is thus remark- ably like the mosquito, only a little larger and stouter built, but may instantly be distinguished by its not possessing Ihe drumstick-like spirit on Us back so characteristic of the mosquito. 283 Report of Investigations in Assam Hemiptera (Capsidae). 567. I watched this insect capturing the mosquitos and transfixing them with its powerful proboscis. It is, I have no doubt, the natural enemy of the mosquito and the planters' greatest friend. If the collections brought in by the children are carefully examined, there will be no difficulty in picking out a few of this insect, for they are, I fear, regularly gathered from the idea that they are mosquitos. Once seen they may be readily enough recognized, even by the children. 568. I would suggest that the greatest care be expended on the encouragement and the multiplication of this insect. A few might be placed in a cage, consisting of a tub with growing tea bush enclosed by mosquito-curtain cloth and live mosquitos daily given them to eat. If the children employed to catch mosquitos, were made to feed these insects with live mosquito, they would soon be recognized, and their destruction discontinued. At the same time the life history of the REDUVIID should be studied, with a view to discovering a method of artificially increasing their number, by breeding them in captivity and liberating large swarms on the estate. 569. I am more hopeful of this little parasite than of any of the other remedial measures alluded to above. The collections at the Indian Museum have not sufficed to enable me to name it for the present; it is apparently an insect which has never before been collected. My specimens have been preserved in Tube No. 89. 570. On visiting the North bank I enquired of Mr. Lindsay Alexander if he had discovered any insect feeding on the mosquito. He replied that he had, and accordingly sent out his collectors to find some for me. Two species of plant-bugs were brought in, one be- longing to the genus Melamphaus (Tube No. 123), the other to Sycanus (Tube No. 389). The former is an insect about an inch in length and with a reddish body below, the other about three quarters of an inch in size and quite black. I had not the opportunity of witnessing these devouring the mosquito, but Mr. Alexander assured me that he had kept them in captivity and fed them daily with the mosquitos brought in by the children. Here then we have two more friendly bugs that should be studied and encouraged on every hand. But I should suspect that these species would prove less tractable than the smaller and more active REDUVIID above alluded to. I was considerably surprised to find that that parasite, found fairly plentiful in the mosquito-infested gardens of the South bank, was unknown on Tea Pests and Blights. 289 The Tea Mosquito. the North, and that its place was actually taken by the large species mentioned, which I had not previously seen in any of the gardens to the South. There no doubt are other insects that prey upon the mosquito, besides those found by me. Mr. C. N. Harcourt, of Ging Factory, Darjeeling, tells us that a small spider had been noticed by him to attack it. The number of species of spider that might be collected in a Tea Garden would be very great and are all possibly friendly. But I never observed a species of spider to attack the mosquito or, indeed, any of the tea pests. 571. So far as I could discover, none of the species of ladybird beetles are parasitic on the mosquito. My opportunities for study were, however, too unsatisfactory to justify my affirming that they do not live on the mosquito. Ladybirds have been found of so great value in other countries, and with agricultural pests generally, more especially with scale-insects, that it would be unwise to conclude that they are not likely to be found of value with the mosquito. I should, however, strongly urge that my discovery of a parasitic REDUVIID receive the most careful consideration, as that insect seemed to me to give every prospect of its being of the greatest service to the tea-planting industry. 572. Parasitic Fungi as a Cure for Mosquito. In the intro- ductory review of the historic facts that bear on the study of mosquito blight, I have alluded above to a suggestion made by Mr. J, Wood-Mason, namely, that an effort should be made to discover some parasitic fungus that might be employed in the eradication of mosquito. The idea is a most admirable one, and has recently made considerable progress in other countries and in connection with other industries. I commend it as worthy of the most careful enquiry. So far as my investigations went, however, I failed to find any mosquito or other insect that gave evidence of being parasitised. That, however, cannot be looked upon as in any way detracting from the value of the propo- sal. To bring about the result indicated would necessitate the form- ation of a laboratory for advanced microscopic research, and the discovery of the desired fungus might be protracted for years. Diary Notes on Mosquito. 573. It may help to exhibit the distribution of this pest, and also to mainfest some of the opinions held by the planters regarding it, if I publish 19 TEA MOSQUITO : REMEDY. Spiders. Con/, with para. 642. Ladybirds. Con/, with paras. 331, 608, 614.' Parasitic Fungi. Con/, wi para. 522. 290 Report of Investigations in Assam Rhynchota (Capsidse). HELOPELTIS THEIVORA. Adult Insects First seen. Con/, with para. 561. Adult Insects First seen. Thinks it does not Hibernate on the Tea . Spread from Lower Portions. Prevalent under Shade. Immature Insects Appear First. here a few passages taken from my daily observations made during my rapid tour through Assam : " During a visit to Cherideo, Sibsagar District ( 2Oth March ), an important observation may be said to have been made, namely, the fact of no young mosquitos having been seen, nor any eggs though carefully looked for. This would seem to point to the inference that the first batch may germinate from eggs deposited on some other plant than the tea, that they mature there and fly to the tea subsequently. If this be'. so, then later on, as the pest increases, eggs and larvae should be both found on the tea. The lesson from this would seem to be to keep jungle down and at a dis- tance, to pluck hard all affected bushes early in the season, and even to again prune and destroy the prunings so as to check the germination of the eggs deposited on the tea. (Tube No, 164.) " On the 6th April I had a conversation with' , Superintendent of, in the Sibsagar District, on the subject of mosquito blight. As it may very possibly be found of interest, the chief ideas may be given here in the form of question and answer : 1. Do mature or immature insects appear first ? Mature. 2. When do they appear P May or June, though one or two may be seen earlier. 3. When do they leave P End of November. 4. Do they appear on any particular side of the garden P Round the sides near jungle. 5. By eradicating the surrounding jungle to a considerable distance and pruning the tea freely, badly affected bushes are got under to a large extent. 6. Do you believe the insect hibernates on the tea P I cannot say, but think not, for the reason that after November and during pruning it is rarely, if ever, seen. 7. What sort of soil, would you say, is the prevailing feature of the estate P Black sandy loam with red clay underneath ? Possibly forest, not jungle soil. On the 8th April I had a conversation with Mr. L. G. llbert, Manager of Moran in Sibsagar District, on the subject of Mosquito Blight. Following the plan adopted in the previous record, the substance may be here given in the form of question and answer : 1. When do you get mosquito P June, when first seen j but not to the extent to injure the tea until August or September. 2. When do the insects disappear ? Seen to cease feeding in October. 3. Where do they come from ? They spread from the lower portions of the garden near halluhs in which the so-called wild Cardamomum grows. 4. Have you seen it feeding on any other plant but the tea? Never seen it on any jungle plant, but some years ago I planted Hibiscus near the garden, and it became badly affected, in fact the mosquito attacked both tea and Hibiscus alike. I also think that it attacks the San tree (Albizzia stipulata). 5. Does shade affect it P Yes, most prevalent under trees. Ficus and Cedrela seem to be its favourites, more especially the former. Indeed I think it may even be said to start under fig trees. 6. Have you observed whether the adult or the immature insects appear first P Immature, in largest quantities. 7. Have you found any method of eradication ? Cutting down jungle and shade, pruning the affected parts severely, and burning the prunings. This is done at pruning season November and December. Tea Pests and Blights. 291 The Tea Mosquito. At a garden visited on the 8th April (in the Moran Section of the Sibsagar District), I found the mosquito most prevalent in low land near the jungle. Although this garden has a large section under China plant, the mosquito showed a decided preference for the Assam indigenous. (Specimens in Tube No. 6.) Mr. S. E. Peal, during a conversation I had the pleasure to have with him on the gth April 1895, said that mosquito appeared first about 1867. Mr. Jenkins thought it was bad cultivation, others assigned various reasons. On being invited to narrate what led to his discovery of its action, he said that for several successive days he sat underneath a badly affected bush and watched until he saw the insects that punctured the leaves. Jenkins denied this discovery even then. Peal demonstrated it by putting fresh leaves in an empty kerosineoil tin along with a few insects next morn- ing the leaves were all punctured, this was satisfactory proof of a very im- portant discovery. In this connection he remarked that it was curious that it should puncture the upper surface only, though it hides on the under, when disturbed. He informed me that he first saw mosquito at Jeypur ( Tingkong), an isolated garden separated by many miles from any other estate. Soon after the insect became general all over the greater part of the South bank. On being questioned whether mature insects or the larvae appeared first on the tea bushes, he replied that the early ones seen by him were all wingless and red. It was in fact a couple of years after he had proved that mosquito punctured the leaves before he identified the mature insect. On being pressed as to whether now-a-days the advent of this scourge was in the perfect or larval condition, he replied that he believed it was the latter, but that both conditions were, as a rule, established before their presence had been detected. He had never made experiments, during the early part of the season, to test the comparative abundance of one condition over the other. Asked as to the colour of the Assam mosquito Mr. Peal said, he had never seen a green one, and did not believe they assumed that colour on having sucked the juice of the tea plant. Speaking of the various efforts towards eradication Mr. Peal said, he had once assigned plots of the gardens to certain boys. It was their duty to keep their sections clean, and they were accordingly threatened that they would be punished for every mosquito found. The pest was in this manner exterminated in about a week. Adverting to the enquiry as to the habitat of hibernation he said, that he had once marked down a bush on which he found mosquito recur- ring for four years consecutively, but they never seemed to extend to other bushes hard by. Accordin'gly he thinks mosquito must hibernate on the tea itself. He, however, admitted there was truth in my remark that the bush in question might have been a jat specially appreciated by mosquito, and one accordingly that should not be cultivated. He farther informed me that he had observed a stream of mosquito following a line, as it were, along the path of the wind. He said also that he had seen the blight on rejected tea, but not to his recollection on wild tea. Does not recollect his having said that mosquito punctured wild pan.* That remark was in consequence of my having said, that, though I had searched hard for pan leaves punctured or for mosquitos resting on the pan, I had failed utterly to confirm an observation which, I believed, he had 'made, namely, that it had been seen in the jungles puncturing the \v\\dpdn. * See the passage quoted from a paper by Mr. Driver, page 277 above. 1 9 A TEA MOSQUITO. Preferred Assam Indigenous. Attacks the Upper Surface of Leaves. Immature Insects Appear First* Colour of Assam Insect. Con/, with paras. 5Ti t 52S, 629. Preference Shown for Certain Bushes. 29* Report of Investigations in Assam Hemiptera (Capsidse). HELOPELTIS THEIVORA. Adult Insect First Observed. Method of ivestlgating Mosquito. Puncturings Experiment Adhatoda as an Insecti- cide. Coupling of Male and Female. No Change in Colour on Sucking the Sap. Experiments with Other Pests. During the inspection of Atkhel on the way to Amguri (i8th and igth April), I asked the superintendent about mosquito. Ke said that he had distinctly observed for two years that the adult black-winged insect first appeared, and that gradually the percentage of immature or red insects increased as the season advanced. (Collections in Tube No. 229.) Visited Amguri on the 21 st April. Mr. Buckingham very kindly arranged to have one or two tea plants growing in tubs and each enclosed by a light bamboo frame work covered with mosquito-curtain cloth. The cloth had been made in the form of a tube open at both ends. The lower end was securely fastened around the tub, and the top tied into a knot with a string, so that it could be opened as the door into the enclosure when so desired. On the afternoon of the 22nd April, some eight or ten live mosquitos, of various ages, were placed within one of the enclosures. Before being intro- duced, not a leaf snowed any signs of mosquito blight, but in the morning every young leaf on the plant was covered with spots. There was no dif- ference observable in the size or shape of these markings that is to say, there was no distinction into the punctures that might be attributed to the young, as compared with the old insects within the enclosure. This obser- vation, may perhaps be regarded as to some extent disposing of the state- ment made originally by Mr. Peal, and often since by others, that certain minute circular spots (like punctures) seen on tea bushes, had been made by the immature mosquito. Syringed these insects in the forenoon with a preparation of Adhatoda of three hours' maceration. No result, the mosquitos though rendered stupid and inactive, were not killed. Syringed at 9 A.M. 23rd, insects still not killed. It thus appeared that Adhatoda was useless for the purpose it had been recommended in connection with this insect, but of coarse the maceration might not have been properly prepared. Longer steeping might be necessary. As I was to be at Amguri for another day only, this experiment could not be repeated. But I tried preparing the insecticide by boiling, result the same. I then syringed certain other mosquitos with the cold infusion made rapidly, still the insects were not killed. April 22nd made another enclosure with one-year old plant. Took pair of mosquitos (male and female) found in union. All the perforated or otherwise injured leaves were previously removed from the enclosed plant. The pair remained united for three hours, on separating they flew off to the young leaves and each commenced to puncture. April 23rd, two young leaves completely covered with spots. No change in colour of mosquito after having sucked the juice of the tea leaves. April 24th, three leaves completely covered with punctures, also young stems stained as if from punctures in depositing eggs. Was unable to com- plete the investigation as to period when the young larvae would appear since I had to leave Amguri. In carrying the tubs with me the en- closures got destroyed, and the experiment was thus rendered useless. In my second mosquito observation cage I had the surplus insects killed. Yesterday one pair of mosquitos united. It is presumed, there- fore, that eggs may have been laid. If all mosquitos had been left, they would have killed the plant outright hence their being removed. There were in all some twelve insects, but the immature ones did not seem to make much progress, nor the old ones to loose much of their activity during the four days' confinement. Twigs with brown patches on young shoots and nearly all the leaves punctured but no appearance of eggs. No change in colour of the mosquitos within the enclosure. Tea Pests and Blights. 293 The Tea Mosquito. In my third observation cage I introduced on the 25th April one of the sandwich caterpillars. In less than 24 hours it had united and partially eaten three leaves. Added also one caterpillar of Dasychira mendosa. In one day it had eaten several large holes in one leaf. It works on the under surface, and at night. Added also two limpet caterpillars. They attached themselves at once to the leaves and each formed a large patch of spots in a couple of hours. They seem to cause a decomposition of the tissue of the leaf by the force of suction. A comparatively short time will suffice (say half an hour) to form a circular patch of killed and partly devoured tissue. Having satisfied myself as to the peculiar action of these cater- pillars, I had to remove them or they would have rapidly killed my tea bushes. I have mentioned these circumstances of imperfect experiments in order to demonstrate the ease with which most of the obscure features in the life of the mosquito might be solved. At present it is not known how long the individual lives ; what time is spent in the condition of egg; the dura- tion of the larval state, the number of generations that take place a year, nor the still more important point whether or not the insect hibernates on the tea bush. Any planter who would take the trouble to have half a dozen two-year old plants placed in tubs and enclosed either with cloth or fine wire gauze might make the necessarily daily observations required to solve these and all the other obscure points in the life of this insect without either any appreciable expense or trouble. I had to change my abode almost daily, and it became, therefore, an impossible task to make observations on plants and insecls that had been jolted along a dusty and hot road all day long. I tried my best, but failed, and I lagged about with me over Assam some half a dozen plants in tubs mainly with the object of demonstrating the simple nature of the appliances required to collect the scientific details so urgently necessary, before we can be said to be in a position to decide upon any definite mode of attacking the insect pests of the tea plant. (Specimens preserved in Tube No. 237.) April 24th, visited a garden in Jorhat Division. Mosquito rare. At a garden visited by me on the 25th April in the Jorhat Division, I found no mosquito. At Jorhat, on the 26th April mosquito was said to be rare. At Badulipar (May and) I found no mosquito, though unpruned tea existed. that Adhatoda did not kill mosquito, but that it stupefied it so that it could be easily caught. At Panitpla I was told of several causes where gardens badly infested with mosquito had been set fire to, with the result that, when the trees sprouted the mosquito never returned. At Makum, on the 2ist June I found mosquito on one or two leaves. At Tingri visited on the 26th June, mosquito was occasionally seen. Mr. J. Alston and Mr. Walker were good enough to take me over Sukerating on J une 3oth. While doing so, they gave me a most interesting TEA MOSQUITO. To Solve tha "e History Mosquito. 3'; Firing Badly affected Estates. 294 Report of Investigations in Assam Rhynchota (Capsidse). HSLOPELTIS THEIVORA. Garden Recovered. Appeared near Shade. Mosquito Reported on Mango. account of the serious visitation of mosquito that garden had sus- tained, and the method adopted for the eradication of the pest. As I am permitted to publish the information, I shall endeavour to relate the subject of our conversation and the facts given to me. In 1886 mosquito appeared towards the end of the season, 4,000 maunds of tea had been made that year. In 1887 the pest spread all over the 450 acres and the yield fell to 1,600 maunds. In November and December of that year the entire garden was severely pruned and also trenched, and about half green soil manured, the prunings were burned on the soil along with bamboo and other dry materials brought from the jungles for that purpose. It was set fire to on the wind side, and it burned for several days. The bushes were thus scorched and about i per cent, killed. The whole garden became black, and looked as if entirely killed; but new shoots sprang from the roots, and in a remarkably short time it had the appearance of a new garden. For about 20 feet all round the garden the jungle was cleared and also burned. Mosquito entirely disappeared and has never returned, and the garden has, moreover, been much improved. It sprouted late and was tipped only once or twice until it came regularly into bearing in July. That year (1888) it yielded 3,685 maunds. As seen at the present time (June 1895), the bushes may be described as branched from the ground and each has so many strong erect branches that they form a dense dome. It is said to yield 10 maunds an acre, but that mcludes a 100 acres of young tea recently opened out. There was shade and bamboo clumps along the main road, and the mosquito appeared in that part of the garden first. During the plague of mosquito all the young mango bushes in the bungalow garden were also punctured and the twigs killed. The insects were seen by three independent persons puncturing, and the red immature insects were also found and collected from the mango trees. Mosquitos were observed in the jungles on a Solatium (Bengan kata) or wild brinjal. Maesa indica is prevalent outside the garden, and the leaves are punctured, but the mosquito on that plant was recognized as a different species from that which attacks the tea. The story of the mangoes being seen to be punctured by the true tea mosquito interested me greatly, and I at once made for the fruit garden in order to see if any mosquitos could be found on them now. All the young leaves were undoubtedly spotted as if punctured, but no trace of mosquito could be found. Moreover, the centre of each spot, or supposed puncturing, was seen to bear a fungoid growth which never happens on the mosquito puncturing of the tea. I was thus sceptical : the story of the true mosquito on the mango. And I may add to the above extract from my diary that I have since, all over Assam and Northern Bengal, found the young brownish-green delicate leaves of the mango spotted in the way mentioned above, and think it likely that mosquito may have been seen resting on the mangoes, and that fact, coupled with the spotting of the young leaves, was probably taken as proof that they punctured and sucked the sap of the mango as well as le tea plant. Planters would, however, do well to keep a close watch on their avenues of mangoes since my observations by no means prove that the above report was inaccurate. I visited Patalipam (North bank) on July 6th in company with the Superintendent Mr. J. Lindsay Alexander, who had most kindly come to Uibrugarh to meet me and to convey me in the Company's steam-launch Tea Pests and Blights. 295 The Tea Mosquito. The garden consists of a rich sandy loam, so much so that earth will not adhere to the seedlings on being transplanted. It is, however, a garden very badly attacked by mosquito a fact opposed to the idea advanced some years ago that that pest did not prevail near running water. Patalipam is on the banks of the Subensari river. On going into the garden I at once observed one thing very peculiar about the mosquito found here. The effect of its puncturing was quite different from that observed elsewhere. I was immediately struck with this, and refused to believe that it was mosquito, upon which my com- panion smilingly said, there would unfortunately be little difficulty in con- vincing me of that fact. In a few minutes his coolies had captured a hundred or so of the insects in all stages. But they were all green in colour even down to the most minute larvce. The adult males were, almost uniformly black with a tinge of green, and the females pale green shaded into darker tinges, the belly being almost white. They were devoid entirely of the orange-yellow colour on the pronotum, the body was not yellow, nor was it found to possess the black bands over the back of the anal extremity. The insect was also observed to be considerably smaller than the brilliantly coloured mosquito seen on the South bank. I had the Indian Museum Notes with me at the time of examination of the live insects, and compared the drawings and descriptions with a large number of this mosquito in all stages of its growth, also with my preserved specimens of the South bank mosquito. I am aware that it has been affirmed that the green colour, often recorded prior to this, is due to the insects sucking the sap of the tea leaf. On this point, for example, Mr. E. T. Atkinson (Indian Museum Notes, Vol. /., page 180) says of the larvae " colour amber-hyaline, but after sucking the juices of the green leaf for some time it becomes of a greenish colour." If that be so, then during my entire residence on the South bank, the mosquito must never have been feeding for, though I looked into this point with the utmost care, I never saw one that had the very slightest greenish tinge. More- over, I reared the mosquitos within specially prepared houses for that pur- pose. I watched the red larvae as well as the perfect insects puncturing and sucking the juices of my tea bushes, until the bushes were almost killed, without witnessing the slightest change in the colour of the insects. I simply cannot credit this story of change of colour. The mosquito of the South bank, when scarcely larger than the point of a pin, is almost bright scarlet, and, as it gets older, becomes orange, then, as the wings form, it turns into a dirty greyish pink, and finally with the perfect wings assumes the adult condition. I must have received thousands upon thousands of samples for, wherever I went, I had the day's collection made by the coolies brought to me for examination. I, moreover, preserved some seven or eight bottle-fulls of these insects in all their stages, but I never saw a green one. I had intended to draw attention in my report to this mistake regarding the green colour, and, therefore, I was naturally surprised when I reached a garden where the mosquitos were green at every stage of their existence. This was all the more surprising to me when I found this peculiarity associated with a distinctly different mode of puncturing the leaf. Though not an entomologist, I am accordingly satisfied that the insect to which I allude is a distinct species. I expressed that opinion to Mr. Alexander, and he at once replied, " I quite agree with you and, moreover, we possess both species. The red form is extremely rare, but I think I may be able to get you a few." His collectors were accordingly despatched on that quest, and, sure enough, brought some of the characteristic form of Helopeltis theivora though only in the adult condition. MOSQUITO. Presence of Punning Water. Green Coloured Mosquitos. Green Colour said to be due to Sucking Tea Sap. Con/, with paras. 617, 62S. Red Mosquito. A Distinct Species. Report of Investigations in Assam Hemiptera (Capsidae). I must, therefore, leave future investigators to confirm my observations, and give a new name to the green Helopeltis or to exhibit the mistakes I may have made in the study of the North bank insect as compared with that on the South. Since writing the above note in my diary, I have been told that the green insect is occasionally found in some gardens on the South bank, so that it is probable they may be both equally widely distributed. But whether separate species, varieties or only different conditions in the life of one and the same species, the red form is that characteristic of the South bank, and the green that met with on the North bank of the Brahmaputra. But to continue the story of the North bank insect. I may say that during my visit to North Lakhimpur Mr. Alexander informed me that in his experience this insect prefers the hybrid to any other teas. In Patali- pam it usually appears about July, and continues till the end of November. But in Dirpai it is present throughout the year. Dirpai is a small garden of 150 acres extending in a long band from the Subensari river into the forests due east. The part most affected is the northern half. Mr. J. Lindsay Alexander informed me that he tried an experiment to prove whether the mosquito hibernated on the tea or in the ground around the bushes. He had a bush completely encased down to the ground with very fine wire gauze. He placed inside a good few live mosquitos. The leaves were all punctured, and continued so till the end of the season. He left the covering without interfering with it in the slightest until the bushes all around were next year badly affected. He then removed the cover. Not a leaf was punctured and the bush showed a bright green colour that for a few days contrasted strongly with the others. But being left exposed it was soon again blighted. He accordingly inferred that the insect does not hibernate on the tea, nor in the ground around the bush. This, as I explained to Mr. Alexander, was an experiment of the right kind, but by itself it could prove little or nothing. Had it been repeated once or twice, and not with one bush but with several, it might then no doubt justify the inference he had drawn. The confined condition of the bush might, however, be unfavourable to the life of the insect. The larvae might have made their escape. It may have been opened too soon. May not have gone far enough below ground. One such experiment for many reasons might very possibly be misleading. But I added that, so far as I heard, this was the only instance of an experiment to trace out the life history of this destructive pest having been made by a planter. Doubtless many more such experiments have been made and not com- municated to me. It would not in fact reflect much credit on a body of able and enlightened men who possess every facility and opportunity necessary for the solution of the obscure points regarding this their most serious pests, if it could be said that for the 20 years of its ravages they had not put forth the slightest effort to assist themselves. I shall be glad, therefore, if these remarks call forth the nature and results of all other such experiments that may have been performed. The results of experiments with Adhatoda, as an insecticide against Mosquito, I was told, had been contradictory. In one garden it was found useful, in another not. At Gopesadarhu, Charali, visited on the I2th July, the Mosquito met with was found to be the green form. As a rule, it comes in July and stays till December. If " forcing weather " occurs the plants are able to throw it off. (Tube No. 126.) Mijika Jan, Charali, I3th and 1 4th July 1895, Mr. G. H. Swinley in. formed me that, long continued damp weather and no sun, say in Tea Pests and Blights. 297 Appendix to Chapter on The Tea Mosquito. September, brings out mosquito until the garden in some years is next to useless. It is the form with green larvae. On the :6th July I went out through Koliabar with the Manager Mr. Wood. Some parts of the garden are low undulating valleys, but the better parts are upland flats of rich red clay. The tea is mostly poor j at planted too far apart. If interlined the outturn might, I should think, be vastly increased. In point of rainfall there is a vast difference between the gardens above the Nowgong hills (Sibsagar and Golaghat) as compared with those below. In Koliabar mosquito is often bad on poor jots, but the red kind is met with. At Kaliden visited i6th July, I was informed mosquito was unknown though present in Koliabar, only 13 miles distant. The Manager Mr. N. Barry told me he first saw mosquito in Cachar. He believes it was first recorded about 1864 and at Bura Jalinga. The following year it was noticed on the ping tree a tree something like a mango with smaller and darker leaves. The insect was actually collected from the tree, and its method of puncturing studied. At Salonah, Nowgong, visited xyth July, Mr. Henderson informed me that mosquito had never been known in that neighbourhood. Mosquito has not as yet visited Solal, but I found a very few leaves punctured with it at Seconee (July i8th, 1895). On 2oth July I visited Nahor rani, of Tezpur District, a garden that has much new tea of Assam jats. Near the bungalow on left-hand side of main road I found a good many leaves punctured by what I took to be mosquito, but failed to find the insect. The leaves seemed to be punctured in the manner ascribed by me to the Sibsagar insect. APPENDIX TO CHAPTER ON MOSQUITO BLIGHT. (Con/, with para. 557.) FUTURE ENQUIRY. 574. I -would suggest that future enquiry into the subject of this pest might be framed on the lines indicated by the following, among other, subjects : 1. Location and Condition of Garden : (a) Geographical, viz., district and sub-division in which situated. () Physical features of garden, e.g., level, hilly, grass land, or forest clearance, as the case may be. (f) Nearest river and direction from the river, e.g miles east or north, etc. (J) Position of jungle, e.g., surrounded and the nearest other garden being .... miles to north, south, etc. : or jungle lies on the north side : jungle kept well back, nothing to speak of nearer than .... miles : surrounded by grass land: practically surrounded by other tea estates and nearest tea garden lies to .... by miles. MOSQUITO. Red Mosquito on China Plants. First Appearance in Cachar. Unknown. Points 298 Report of Investigations in Assam Rhynchota (Capsidae). HELOPELTIS THEIVORA. Cultivation. Peculiarities of the Insect (i) Relation to rice cultivation, e.g., approximate height above the rice annual inundation ; distance of rice cultivation from the tea estate. (/) Hullahs, e.g., depressions with connecting nullahs : their position within the garden : condition, annually cleaned out and water given free passage, or filled with jungle and water more or less stagnant. (g) Nature of soil, i.e., sandy loam, red-clayey loam, black-clayey loam or rich black loam (rich in humus). (^) Climate, e.g., direction of prevailing winds : average annual rainfall : month of highest rainfall : approximate period of monsoons : average day temperature in the shade during March, June and October : month of highest, and month of lowest, temperature. 2. Cultivation: (a) Number of heavy and number of light hoeings a year. () Number of weedings. (c) Condition of drainage, e.g., depth of trunk drain or canal ; depth of main drains within the estate : depth of lateral feeding drains : distance apart of lateral drains : extent and nature of terrace cultivation. (d) Season of pruning. (t) What is done with the prunings ? (/) Plucking season : when does it commence ? what date could be called mid-season ? usual date of termination of pluck- ing : nature of plucking, viz., " two and a bud," " three and a bud," " two and a bud with portion of third leaf," etc., etc. When mosquito appears bad, state the extent of plucking then instituted, and its effect on the pest. 3. The Mosquito ; (a) From the records of the garden (the recollection of the oldest sirdars) in what year did it first appear ? (3) Did it attack any particular portion of the estate first ? if so state the position of that portion (in relation to the re- mainder, e.g., an out-garden. . . . miles to the east or west as the case may be), to the main expanse of the estate : ap- peared on the portion of the garden nearest to the jungles, in other words, on the east or north, etc., of the estate. Tea Pests and Blights. 299 Appendix to Chapter on The Tea Mosquito. (t) In what month does it usually make its appearance, and in what month does it disappear ? (d) Does it appear at one point, and spread from there all over the garden, or simultaneously break out here and there at one and the same time ? If the former, describe the posi- tion and peculiarities of the portion of the estate in which it usually makes its appearance. (e) Does it show any special favour for certain jats, such as China hybrid, indigenous Assam, etc. ? does it show any preference for unpruned tea, for light pruned tea, for collar-pruned tea, for seedlings, or for old plants ? (/) Have you any grounds for thinking it hibernates during the winter months on tea? if so, kindly state these as fully and freely as possible. (g-) Does the winged insect or immature wingless insect appear first? This, I am aware, is difficult to answer, since the insect may have been some weeks in the garden before its presence had been detected, but an approximate answer could be obtained by counting the relative proportion of mature and immature insects in the daily captures for the first month or so. (h) Kindly preserve in a bottle the first day's collection of mos- quito, using as a preservative fluid a weak solution of spirits of wine or better still half water, half glycerine : then later on, when the pest might be said to be at its worst, preserve another day's collection in a similar bottle. Place on the bottle a label bearing date of collection and name of garden. Forward these to the agents along with your replies for each year to the above enquiries. 4. Experiments to test ttie Life History of the Insect : (a) Have half a dozen two or three-year old plants well rooted in separated tubs. Construct a bamboo frame work over these, and enclose it by mosquito-curtain cloth ; tied tight around the tub and have it sewn completely all over the frame work. Fine wire gauze may be used if pre- ferred. On one side of the net enclosure, sew a tube of the cloth about two feet long and sufficient to allow the arm to be inserted, the mouth of the tube being tied around the arm, so that none of the insects can escape Report of Investigations in Assam Hemiptera (Capsidae), HELOPELTIS THEIVORA. The Life of the Insect. Number of Eggs. () Place your half dozen plants on a shell, say 2 feet high, so that they can be examined with ease. Construct over them a small roof so as to protect them from actual rain, but not to exclude light. (f) Place within two of your cages, two pairs of winged mos- quitos that appear fairly healthy that is to say, two pairs for each cage. The female is larger bodied than the male, and not so black in colour. Leave these alone, for the entire season, unless they appear to multiply to the extent to threaten the life of the plant. In that case kill off a number. Watch them daily to see how they are getting on, and record your observations, more especially towards the close of the season. Do not allow these two plants to be in any way interfered with, nor the cages to be opened except by inserting the hand through the arm-tube to water the plant or dig up the soil or prune it if found necessary. Next season watch with the greatest care to see if mosquitos re-appear upon these plants, and, if possi- ble, discover where they come from, whether they appear as winged insect or as immature larvae. This experiment, if performed by several separate observers, would very pos- sibly establish where the insect hibernates. (d) In another pair of cages place within each, one pair of young mosquitos, the female, if possible, with the body not greatly distended. Watch them couple. Record the date. Watch, if possible, the deposit of the eggs. Record if the adults again couple, and for how often. Record the first appearance of the larvae and how many, also the dates of all subsequent broods. Kill off the original pair, and from the first brood select one winged pair, male and female, kill off all the rest. Record the date of coupling of this new pair, record the appearance of their larvae, and so on with a third or a fourth, etc., etc., to the end of the season. You will thus prove the period the egg remains before hatching, the time taken for the larvae to reach maturity, and the number of broods each year. (i) With the third pair of cages test the age to which the adult can live, and the number of eggs each female can produce during her life. Place a healthy pair in each of you r Tea Pests and Blights. 301 Appendix to Chapter on The Tea Mosquito. cages. Let the female lay her eggs, and on the larvae appearing kill off the original pair and select a young pair for observation, kill off all the others. Record the date of union of the young pair, kill all the larvae as they appear, noting the number of broods before the male and female die of old age. Repeat this experiment and watch carefully whether larvae are ever borne alive, t.e., without passing through the condition of eggs. In each of the above three experiments I have suggested pairs of tubs so that a comparison may be made. It would, however, be a good plan to similarly reserve a fourth pair of bushes enclosed in the same manner and placed alongside of the other three pairs in order to see the extent to which the mosquito injures the bushes, all four pairs being under precisely similar conditions, the comparison would be a fairly safe one, the more so as it might be performed by a dozen or more observers all over the province. There are doubtless many modifications of the experiments and further stages in the enquiry that would suggest themselves naturally to persons who took a real interest in the matter, but let me add, in conclusion, no such experiments would be of the least Value, unless a diary of each observation and each step taken was carefully recorded. The six or eight tubs should, therefore, be numbered one to eight, and a little note-book preserved regarding each into which the record would be made from day to day, right through the entire period of observation. Other Circumstances and Observations. In addition to the series of questions and experiments indicated above, it would be most desirable that every encouragement should be given for the expression of individual opinions and testing of theories, regarding the insect. So long as full particulars are given, in the reports furnished, the re- sults could be readily worked up by the person employed to examine the body of evidence brought to light annually. As matters progressed, further questions no doubt would be found desirable, and additional experiments suggested as necessary. 66. (c) Paecilocoris hardwickii, Moore. References. J ourn. Agri.-Hort. Soc. Ind., Vol. II., Proc., Nov. 1869, p. ix. Proc., soth Dec. 1870, p. Ixxxvi . (Reg. No. a, Tubes Nos. 165 and i 9 8.) TEA MOSQUITO. Viviparous. Cow/. with paras. 338, 377. Report of Investigations in Assam Hemiptera (Jassidae). 575. In connection with the subject of possible natural enemies to the mosquito, I may bring to mind a bug that may be said to occur here and there throughout the tea districts of Assam. It belongs to the genns Paecilocoris. In November 1869 Mr. Edgar, of Cossipore Tea Estate, Cachar, sent what I take to be this species to the Agri.- Horticultural Society for determination, and Mr. Moore named it Paecilocoris hardwickii. Mr. Grote in forwarding Mr- Moore's report said that, " this insect had been observed as infesting the tea plants of Assam many years back. " It is found in clusters of five to ten, low down underneath the shade of the bush. They are most inactive creatures and never setem to be doing anything. They are between half to three quarters of an inch in length and a little less in breadth. Are pale yellow coloured with curious finger-nail-shaped orange-red patches round the thin margin. The head is bright-metallic blue. The thorax scarlet, and behind the thorax there are three metallic blue patches, the centre one of the three forming the outline of a triangle. Along the back are three orange-red bands and right over the anal extremity other two metallic blue bands. 576. Mr. Fleet wrote me on the 22nd April that he placed these insects under observation and " could not find that they were injuri- ous, or the contrary. The original ones that I first noticed on a bush, on the 3oth ultimo, have not even moved from the leaves on which I found them." In a subsequent letter of the 28th May he again wrote that, " a second and winged generation of this bug is now to be seen on the bushes." I took the liberty of sending samples of this bug to Mr. Green to obtain his opinion regarding it and to know if it had been seen on tea in Ceylon. The following may be given from his reply : "This is apparently immature, and would eventually develop into one of the large PENTATOMID bugs. It belongs to a plant-sucking family ; but some of them are known to vary their diet by transfixing and suck- ing caterpillars. The habit of this large species should be watched. It may prove to be a friend." Family JASSID.E. 67, (a) Chlorita flavescens, Fabr. GREEN FLY : STUNTED BLIGHT : CRINKLY BLIGHT. References. 7^0 / in Tea Cyclopaedia, 37-38 ; Correspondence I. c. t Tea Pests and Blights. 303 Green Fly or Stunted Blight. 43'49 i Journ. Agri.-Horti. Soc. Ind. t Vol. VIL, Proc., sgih June 1884, pp. xcv.-i>i. ; Tea Planter's Vade Mecum, p. 104; Notes on Tea in Darjeeling, 49 ; Bomber in Annual Report, Indian Tea Association, 1 8g 3, p. 92; Bomber, Chem. and Agri. of Tea, pp. 248-251 ; Ind. Mus. Notes, Vol. II., i6j; III. ; 9-12 i (pt. j), 140 ; IV., 42 ; Cotes, Insects and Mites, etc., pp. 34-36 j Miles, Journ. Micro. Soc. Ind., Vol. V., p. 45 ; Crole, Tea Text-Book, pp. 83, 223. (Reg. No. j.) 577. HISTORY. The first mention of this insect, as a tea pest, will be found in the Journal of the Agri.-Horticultural Society for 1884. On that occasion Messrs. Begg, Dunlop & Co. submitted, for opinion, samples furnished by their Manager of Kumber Tea Estate, Cachar. These were forwarded by the Society to the late Mr. J. Wood- Mason and were identified by him as a Homopterous insect closely allied to " the little Green-flies which are such a pest in the rains in Calcutta." He added that he had met with them frequently on tea bushes, but could never satisfy himself that they did any harm. The next writer on the subject was Mr. 8. E. Peal, but unfortunately he assumed that it was a species of aphis, and called it accordingly " The Tea Aphis" a name which crept into most subsequent books and reports. Having made that mistake he apparently assumed by analogy that it was destructive to tea and gave some startling details of the life of aphides, especially their parthenogenetic reproduction, as applicable to the green-fly. " When young, " Mr. Peal wrote, " it can hardly be distinguished from a small tea bug (mosquito) either in habit or appearance, which might have been expected, seeing that they are closely allied forms. " A writer in the Darjeeling News next an- nounces the discovery of the insect in that district, and this is followed by the author of the little book called Notes on Tea in Darjeeling. Mr. Bamber published the results of some unsuccessful efforts to ex- terminate the insect with insecticides. In his work on the Chemistry and Agriculture of Tea he says that, in Assam it is known as " blister blight," and in Darjeeling as "green-fly blight." The mistake of confusing " stunted blight " with " blister blight " was followed by Mr. Cotes in the Museum Notes ( Vol. II., /d;), but was not repeated in his subsequent special work on the Insects and Mites of the Tea Plant. Mr. Crole, the most recent of writers on tea pests, repeats the old error of " green-fly or blister blight, " while he gives a sepa- rate paragraph on " stunted flush." In this connection he remarks, GREEN FLY. Appearance in Darjeeling. Confusion in Names. Con/, with para. 81O, 304 Report of Investigations in Assam Rhynchota (Jassidae). Earliest Mention of its Depredations. " what is popularly held as a variety of it occurs sometimes when the leaves become crinkling as well, but I have satisfactorily accounted for the cause of it being due to an insect." He would thus appear to separate crinkling leaf from stunted blight, but I regret I have failed to discover the passage in which he has accounted for the former. 578. DEPREDATIONS. Mr. Cotes tells us that a large amount of damage from this insect had been reported in 1891, especially in Cachar and in the Upper Assam Valley. Specimens, he added, had reached the Museum in May from Assam, in June from Darjeeling, and in July from Cachar. " In no case, " says Mr. Cotes, " do its habits seem to have been observed with any minuteness. It was generally supposed in the tea districts, however, to be responsible for the injury caused to the tea bushes, and as this was of a kind that it would be quite capable of inflicting, the probabilities are that it was rightly accused. " But although the species is said to be fairly com- mon in Europe, Algeria, Brazil and Siberia, it would not appear to have been specially reported as being a parasite on crops except in the determination here reviewed of its being a tea pest. 579. The subject of green-fly and its depredations was one that the rapid nature of my explorations precluded me from investigating. So far as I could learn, however, there may be said to be a strong probability that it is quite unconnected with "stunted blight," " crinkly blight," and all the other maladies of the tea plant at- tributed to it. I have no proof, however, -one way or the other, and prefer, therefore, to allow the usually accepted opinions to find a place under the name of this insect, until such time as they have been fully proved or disproved. Let me only add that I fear this insect has been often confused with mosquito, especially by the early writers, who speak of it as having blackened the estates. Indeed I am disposed to concur with the planter, already quoted under the account of mosquito, who affirms that even Mr. Peal's " green-coloured mosquitos " may have been the larvae of the green-fly. Mr. Peal, however, -says that "in attacking tea, the young leaves and stems alone are punctured : growth becomes remarkably arrested : the internodes or stem between the eyes become shortened ; and the leaves present a paler dwarfed appearance. After a time they fall off and the stunted bare little shoots proclaim the blight at once. There is less mark left than by the bug (mosquito), and the effect is Probably Unconnected with Stunted Blight. Confusion. Conf. with para. 329. Tea Pests and Blights. 305 Green Fly or Crinkly Blight. mainly to dwarf the growth and shrivel up the young shoots. I do not think the question of " soil, manure, etc.," have very much to do with either the cause or cure of these insect blights, though it pro- bably has with fungoid ones." A writer, who signs himself " Green- Fly," will be found in the Tea Planter's Vade Mecum to say of green- fly that it " is becoming most common in the Darjeeling hill gardens, the effect of which is to deprive the leaf of its ordinary amount of sap. The leaf is small and stunted, as is the length of the flush, which would not weigh one-fourth of its ordinary weight : and this takes more than twice the ordinary time to come on, and, if left, the bushes shrivel up, and the buds or tips die off." The author of Notes on Tea in Darjeeling gives even a more gloomy account. " It used not to come, until well on in the second flush, but last year it was in the bushes nearly all the cold weather, and came out in swarms during pruning.", " The effect on the bushes is, that the shoots stop growing, leaves shrivel up, and only grow to 2 inches long, showing little eyes at every 4 inches, the length of shoots being perhaps 2 inches and having six or seven eyes breaking on each shoot." 580. Mr. Cotes gives a series of wood engravings to show the effect, or supposed effect, of the insect. These are very instructive and denote clearly the state of affairs that exist in "stunted blight" what- ever be its cause. In the one twig (shown half life size) the parts are healthy and fully developed. Those alongside are stunted and per- haps less than a third the size of the healthy shoot. Commenting on the samples from which these drawings were made, Mr. Cotes tells us that a garden of 199! acres so 'affected, gave less leaf on being plucked than a patch of 17 acres. "To bring the state of things before you," wrote the manager, " in the most comprehen- sive manner, I have pressed some shoots and send them by to-day's post, together with a little bottle containing about 100 of the insects which do, or are supposed to do, the damage. They are so active and difficult to catch that it took a boy a day and half to procure the specimens sent." 581. From what has been said it may have been inferred that lam by no means satisfied that it has been proved that Chlorita flavescens is responsible for the injury attributed to it. I have seen both stunted- blight and crinkly- blight without any green-fly being present. I have frequently found green-fly in vast multitudes without either blight. GREEN FLY. Deprives the Plant of its Sap. Condition in Stunted Blight. tunt without Green-Fly. Con/, para. Report of Investigations in Assam Hemiptera (Jassidae). CHLORITA FLAVESCENS. Zigzag Stem. Crinkly Blight. Experiments to Test the Action. It may be said to be most frequently seen (if not exclusively so) on heavily pruned tea. The shoots are stunted, swollen, succulent, very hairy, and the internodes (spaces between the leaves) deflected right and left in a zigzag fashion. But they are in no way discoloured, and there are no markings or puncturings of any kind. As they ad- vance in age, the leaves rise on end (or stand in a vertical attitude), and become curiously closed up, face to face as it were, along the upper surface, while the midrib in time becomes curled backwards or even twisted spirally, to a slight extent. The texture of the leaves, when these changes have taken place, is also hard, so that they are unfit for tea-making unless plucked early. The buds are also arrested in their growth, so that the bush may be described as banjhi. 582. So far as I could make out, " stunt " is the first stage of this disease, and " crinkly blight " its ultimate development. On old bushes crinkly -blight sometimes occurs by itself, or a state of affairs of a very closely allied nature is produced when the plants are either suffering from insufficient nourishment or defective drainage. The leaves rise up to the vertical position and close up lengthwise, become hard and crinkly without any evidence of stunt or green-fly. The condition of stunt, so far as my experience goes, is exclusively met with on the shoots that spring from heavy or collar pruning. 583. Green-fly is undoubtedly very often found on both stunt-blight and crinkly-blight, but no one has as yet proved that it is the cause of these diseased Conditions. I had a large number of these flies under observation within a cage over a live tea bush, but, though I watched them for hours together, I neither saw them puncturing the shoots nor eating the leaves. During the entire period of my investi- gations, the bushes showed no signs of stunting or crinkling. Similar experiments were performed by Mr. A. T. Wright at Noakachari with a like result. But neither of these experiments were carried out for a sufficiently long period to justify any definite conclusions being formed. They by no means prove that the popular notions regard- ing this insect are mistaken. But in support of the suspicion of a mistake, it may be useful if I give here a few passages from my diary. 584. According to Mr. 8. E. Peal (conversation on the gth April), green-fly does all the good in the world. It makes the bushes branch, and, if good weather follows, a heavy flush will ensue. Tea Pests and Blights. Green Fly or Stunted Blight. 585. The green-fly first appeared to his recollection about 1874 and at Golaghat. It came slowly up the valley and then turned west. It has never been so bad as it was on its first appearance. It took about two years to exhaust its severity. The enemies of the so-called green-fly, he added, seem to have developed and kept it in check for many years past until, as stated, it can hardly now be regarded as a pest. 586. At Badulipar (May 2nd) I thought I observed the green-fly eating the top surface of the tea leaf. Up to this date, though I had watched carefully for hours. I never observed the proboscis inserted into the tissue of the leaf and even at Badulipar all I could say was that the insects seemed more in earnest at doing something than I had previously observed. 587. At Dibrugarh, en the 1 5th June I found the green-fly not very bad, though numerous branches were shown to me as stunted by it. These bore no indication of having been punctured or eaten they were stunted in growth, and that was all that could be said. Green-fly had so far only appeared to a slight extent in Dibrugarh this year : it was bad last. Is generally known as " stunted growth." But when discussing the matter with a planter, he seemed doubtful as to the insect having caused the stunting of which so much had been made by planters. He had seen the insects abundant without any stunting of the bushes. 588. At a garden in the Dibrugarh District, visited on June 27th, I saw a good deal of "stunted flush" with green-fly certainly abundant at ;he same time. On discussing this subject wiih a large number of planters who met together that evening, I found many were dis- tinctly of opinion that green-fly often was to be seen on tea without the stunted growth being produced. There is certainly one observation in favour of the heresy of being doubtful of green-fly effecting what is very generally attributed to it, namely, that stunted twigs and leaves show no indication of being punctured or eaten. It was too late in the season to find my little pink-mite, but I may add that, had 1 been asked for the cause of interrupted growth without having been taken to the plot in question in order to be shown green-fly, I should very possibly have pronounced the bushes as having suffered from the ravages of the pink-mite. 589. Mr. Lindsay Alexander informed me that in his experience green-fly appears in Patalipam generally about May ; it attacks the flush that follows the plucking of April. He told me that he believes the insect eats the skin from the veins of the leaves, thus causing them to turn pinkish, this then checks the circulation of the sap, and thus stunts the growth. When the rain falls, the leaves curl. This is sometimes known as the "crinkling blight" or "stunted blight," but the pecu- liarities that give origin to these conditions do not show till about the end of May. When this occurs, the twigs become very thick, and the axis bent zigzag between, the numerous buds giving the main branch GREEN FLY a Stunted Parts grive no Indication of being Punctured. Eats the Epidermis of the Leaves. Conf. with fink-Mite, para. 7SO. 308 Report of Investigations in Assam Rhynchota (Jassida). CHLORITA FLAVESCENS Doubts Green-Fly Causing Stunt. Stunt showing ifter Pluck- ing. Descending Sap Arrested. Distortion Produced in Bud. Conf. u-ith para. V02. Green-Fly Comes and Goes. the appearance of a broom. It begins to disappear through the elonga- tion of the branches which takes place about the -end of June when the rains may be said to have been fairly established. Heavy pruned tea is most liable to this blight, and the injury is more severe and lasts longer on that condition than on ordinary tea. Although the effects only show up about May, the insect is present from a much earlier date, and may even be very abundant though the bad effects do not appear for some time. Adhatoda was tried with good results at Dirpai. 590. Gopesadarhu, Charali, visited on the I2th July. Had an interesting conversation with Mr. W. A. Steele. He informed me that he doubts green-fly being the cause of the stunted growth generally attributed to it. In proof of this, bushes were examined with the insect on them, some being stunted, others not. He is disposed to regard the stunt as due more to the general conditions of the life of the plant than to any external influence. It appears mostly on heavily pruned tea, the great abundance of shoots being, in Mr. Steele's opinion, more than the roots can nourish. The evil complained of is seen to be intensified by the stunted shoots being plucked, since the fresh shoots come up time after time stunted even long after the insect has disappeared from the plot. He is, therefore, of opinion that heavily pruned tea should not be plucked for some time until the shoots have recovered completely from the defective supply of food. He informed me that he had never seen unplucked heavy pruned tea affected. 591. Personally, I have all along been disposed to view with sus- picion the opinion that green-fly was the cause of "stunted growth." While visiting Noakachari on the 24th April, I expressed my heretical views, and found that Mr. Wright was prepared to concur with me. It was, therefore, with considerable interest that I listened to Mr. Steele's observations. I drew his attention to the fact that the stunted twigs axe abnormally thick and zigzag as if the descending sap had been arrested, thus causing a swelling of the joints. I further showed him by a section through a bud that the distortion is produced before the bud has unfolded, and not subsequently, for the axis of the young buds can be seen turning right and left before they have expanded. I further pointed out that the zigzag wood, 5 to 6 inches below the young buds must have been formed three or four months ago, and therefore anterior to the appearance of green-fly. Mr. Steele explained that green-fly begins about the middle of May. It is often checked by unduly hot weather, of even a week's duration. On the light pruned tea it comes and goes, rarely staying Tea Pests and Blights. Green Fly or Crinkly Blight. more than three weeks or a month. On heavy pruned tea it stays much longer. The insect remains in the garden throughout the year, but only at certain intervals develops to such an extent as to specially attract attention. If, therefore, it be the cause of stunted growth, it is intermittent in its depredations. 592. REMEDY. It will be found that Mr. Bamber experimented with insecticides (mostly solutions containing arsenic) in the treatment of this insect. For a time the plot of bushes syringed was freed from green-fly, but, after the first shower of rain, the insects again returned Mr. Bamber, at the same time, made the observation that the fluid used by him, on several occasions, was seen to kill the tea shoots. These results are practically what I should have anticipated as likely to occur with the insecticide treatment of a winged insect pest. 593. But I am not disposed to propose any treatment for Chlorita flavescens, until it has been satisfactorily demonstrated that it is the cause of " stunted blight" and "crinkly blight." The more natura course is to suggest treatment when we have discovered that we are dealing with the actual cause of the disease, and have learned at leas! a few particulars of the life of the pest concerned. I would, therefore urge on tea planters, the desirability of performing some practical ex- periments with the object of proving whether or not this insect is the cause of the diseased conditions complained of. All that would be necessary would be to have a few healthy bushes enclosed so as to prevent external influences, except green- fly purposely placed within the enclosure. If the bushes become stunted after, say, a couple of months, while a couple of bushes treated in every respect similarly except that no green-fly was placed within their enclosures, the in- ference might be admissible that green-fly was the cause of the disease. Another method might be to clean very carefully a bush in the middle of an affected plot, and enclose it with a fine wire gauze house having, perhaps, a couple of glass windows on the sides to admit light. A test bush alongside, with green-fly within its en- closure, would afford a useful comparison. If the bush from which green-fly had been rigorously excluded improved, while the other bush continued stunted and even got more stunted than the surround- ing bushes in the open, it would be fair to assume that the exclusion of the insect very possibly had something to do with the recovery. Of course the act of enclosing bushes excludes light and air to a large GREEN FLY. Arsenic. Conf irith paras. 381, 489, 559. Killed the Shoots. Experiment Essential. 3io Report of Investigations in Assam Hemiptera (Fulgoridae.) PHROMNIA MARGINELLA Eggs. Does it Puncture the Tea. Tea Leaves with Minute Brown Spots. extent, and these circumstances may have a beneficial or injurious influence. The experiments undertaken would accordingly have to be repeated once or twice, and varied in such a way as to remove the possibility of a wrong conclusion bring formed. 594. The eggs of this insect (according to Mr. Wood-Mason) are laid upon the leaves of the tea. The insects, enclosed within the cage, might be found to lay their eggs, and in that case it would be instruc- tive to follow a series of experiments similar to those indicated with mosquito to trace out the various stages in the life of the insect. Most important of all it would be desirable to note where and in what manner it punctured the tea and caused the injury that resulted in stunted-blight. 595. While by no means satisfied that Chlorita flavescens is responsible for what is attributed to it, I would wish, in conclusion, to say that practically all over Assam I observed tea leaves with minute brown spots on them, not a third the size of mosquito puncturings, which I utterly failed to account for. If this insect be proved to actually puncture the tea, it might be the cause of the minute brown spots to which 1 allude. I would suggest, therefore, that every leaf on the plants within the cages should be removed, that showed spots, stains or defects of any kind. For some time after the ex- periments, here recommended, are regarded as complete, the bushes should be retained within their cages in order to see by comparison of those on which the green-fly had lived with those kept free from that insect, whether any spots subsequently appear. Family FULGORID.E. 68. ( a ) Phromnia marginella, Oliv. References. Journ. Agri.-Horti. Soc. fnd., Vol. VI. n. s. Proc., 2^th June 1879 ; p. xix, Proc., i8th Dec. 1879, p. xli ; Ind. Mus. Notes, Vol. II., pp. 39-40, 92, 95-96, 1 66 ; Vol. IV., 42 ; Cotes, Insects and Mites, etc., pp. 36-37. (Reg. No. J4, Tubes V PP- 2 9~3<>. 615, But as a set-off against the long list of destructive scale-bugs, Tea Pests and Blights. Scaley Bugs. the useful species may be here mentioned briefly : The cochineal insect (Coccus cacti) ; the lac (lakh) insect (Tachardia lacca) : the Chinese wax insect (Ericerus pela) : the Indian wax insect (Ceroplastes ceriferus), etc. 616. Most of the scale insects (like the aphides) secret a sugary fluid much appreciated by several species of ants. Speaking on this subject Mr. Green says, " It was at one time supposed by planters that the ants which are so constantly in attendance upon scale-bugs were preying upon them, and the formidable "Red ant" (CEcophylla samaragdina) was actually imported into some estates with the view of exterminating black-bug on the coffee trees. This is now known to be quite a mistaken idea. The ants are attracted by a viscid sugary liquid emitted by the bugs, and which is in fact, their excreta. This substance is being constantly shed upon the surrounding leaves and proves very attractive, not only to ants, but to flies of all kinds, and even to bees and wasps. It is of the same nature as the " honey-dew," so abundantly produced by aphides. Far from feeding upon the bugs, I believe the ants actually transport them from place to place to found fresh colonies of them in convenient situations. It is certain that the small black nest-building ant (Cremastogaster dohrni),thatis such a nuisance on some of our estates, invariably includes in its nests colonies of mealy-bugs (Dactylopius) and one or more species of Lecanium. " In the Assam gardens I have already said the red and black ant (Cremas- togaster contenta No. 57 above) encloses the black aphis within its nest. Although I did not come across an instance, I have no doubt it uses also several species of scale-bug in the manner Mr. Green describes with C. dohrni. 617. In many cases a fungus will be found in association with scale- bugs. This subsists on the sugary exudation and is not.itself directly harmful to the plant. Under the account given above of the mosquito (Helopeltis), I have alluded to this as being in all probability the " Sooty Bug " of the early writers, who apparently associated it with mosquito. The fungus will be found to grow on the upper surface of the leaf, the part upon which the sugary deposit would naturally accumulate. While distinctly very untidy-looking, it cannot interfere with the respiration of the plant very materially, since the stomata or breathing mouths are on the under-surface. It must, however, largely USEFUL SCALE INSECTS. Ants Useless against Aphides op Scale- insects. Ton/ 1 , with para. 6O9. Scale Insects Protected by Associated Fungi. Conf. with paras. 514, 638-9, 837-8. Cannot be Harmless. 3*0 Report of Investigations in Assam Rhynchota (Coccidae). LITERATURE OF INDIAN SCALE- INSECTS. Friendly Fungi Con/, with para. 628. exclude light, and, therefore, cannot be said to be harmless. Still its chief interest lies in the fact of its pointing the way to the existence of a dangerous scale-bug on the leaves and twigs of the plant, where the sooty fungus exists. But in one or two instances friendly fungi have been recognized, that is to say, fungi that prey upon, and destroy, the scale insects. The introduction of these where they do not already exist, is one of the methods of dealing with scale insects that should receive careful consideration. 6 1 8. I have gone into these details regarding the scale insects collec- tively, because so very little is known of the individual characteristics and methods of depredation of the species found on tea. Let me add by way of conclusion, that I have derived the very greatest assistance from the perusal of Mr. E. Ernest Green's most admirably conceived and beautifully illustrated forthcoming work "The Coccidae of Ceylon." Unfortunately only the first part of that invaluable work has come to hand as yet, but I commend it to all planters who may wish to look into the matter of scale-bugs. It is published by Messrs. Dulau & Co. at 5 for the complete work, and part one, already available, contains thirty-three full page coloured plates. It is in- tended to describe all the species of Coccidae met with in Ceylon most of which doubtless occur also in India but the interest to the planter lies in the fact that it will describe all the forms met with on tea, coffee and other crops, so that the work has a prac- tical value, besides its very high scientific merit. Speaking of the Coccidae, I may as well add that the Indian Museum Notes will also be found to contain several papers of great value. In Vol. I., pp. 59-62, Mr. W. M. Maskell figures and describes two forms of DIASPIN that occur on the tea and gives full particulars of the LECANIIN pt. of Agricul- Pests of Tea Plant, pp. 21-22 ; Bamber, Chem. and 252 ; Ind. Mus. Notes, Vol. II., 59, 168 ; III., p. 52 and Mites, p. 41 ; Howard, U. S. Year Book of De ture for 1894, PP- 261-3. (Reg. Nos. 87, 91 and 117.) 621. HISTORY. Mr. Green was the first to make known the exis- tence of this as a tea pest. Mr. Cotes tells us that it has been reported from Assam and Kangra. The samples collected by me personally and also those procured from Kangra have, however, been identified as being A. theae, Mask., so that it seems probable Kangra should be removed from the habitat of this species. A. camellias was found, however, by me almost frequently in Assam, and I have also two separate sets of collections of it from Darjeeling (furnished by Messrs. Devenport & Co.), so that it may be accepted as fairly general in the Indian tea districts. It is an extremely abundant and widespread species : it has been recorded from England, Portugal, New Zealand, YELLOW BARK LOUSE. Yellow Bark Louse. 322 Report of Investigations in Assam Hemiptera (Coccidae). ASPIDIOTUS Recom- mended. Firing the ishes should be tried. Scale Insect. New South Wales, Hawaii, the. United States, in addition to Ceylon and India. 622. DESCRIPTION. The scales of this species are of a pale-yellow colour, with a reddish or brown central mark, and they are somewhat hairy. They resemble minute oyster-shells, with the younger scales clustering around and often overlapping the older ones. They are crowded together near the axils of the leaves, extend along the leaf stalk, and to some extent up the midrib. In consequence they are thus fairly conspicuous objects and should be easily enough recognized. 623. DEPREDATIONS AND REMEDY. Mr. Green says of this species, " Badly infected plants seldom recover their vitality, the stems become thin and wiry, and seem very reluctant to throw out fresh shoots. There is nothing to be done, but to take out the plant and supply another in its place. The diseased plant should on no account be allowed to remain beside the new one, or this latter also will speedily become infected." So far as I have been able to judge, faring bushes or plots of tea affected by this pest, is fairly successful. The plants receive a severe shock, no doubt, and those that were nearly dead in any case die outright, but a large percentage of the bushes are saved which, as Mr. Green very properly remarks, are certain to be killed, when once this pest becomes fairly established. 73. (a) Aspidiotus these, Mask. THE KANGRA SCALE INSECT. References. Maskell, Ind. Mus. Notes, Vol. II., (pt. /), p. 59; J 0u rn. Agri.-Horti. Soc. Ind., Vol. VIII., n. s. Report ending December 1889, pp. 435-36. (Reg. No. 90.) 624. HISTORY. This insect was described by Mr. W. K. Maskell (Ind. Mus. Notes, Vol. II., (pt. /),/>. 59) from specimens said to have been furnished to him from " Assam, Kangra Valley, etc." Subse- quently Mr. Cotes (Insects and Mites, etc., p. 41), gave A. these, Mask., as a synonym for A. flavescens, Green. The samples collected by me in Kangra, as also those furnished by Messrs. Shaw, Wallace & Co., from Holta Garden, Kangra, were submitted to Mr. Green for favour of opinion. The following passage may be given from his reply : " Your specimen is Aspidiotus these, Mask. That species does not occur in Ceylon though closely allied to Tea Pests and Blights. 323 The Scaley Bugs and Bark Lice. A. trilobitiformis, Green." It would thus appear that the Assam and Darjeeling insect is A, camellise, Signorel (A. flavescens, Green), but that the Kangra insect should be kept distinct under name given to it by Mr. Maskell. It is incorrectly known to the Kangra planters as a species of Lecanium, and its most ready eye- mark, from the characters already given for A. camellias, is that the scales are more widely distributed along the twigs and more crowded at the points of branching than within the leaf axils. It would seem as if this might be a more severe pest than the form met with in Assam and Darjeeling. I would not wish it, however, to be supposed that I think it im- possible for Kangra to possess any other tea scale insect than the one here dealt with. I speak of my own collections and the information I have been able to procure. I came across no species of Leca- nium in Kangra, nor do I know what is meant by Lecanium these said to have been determined by Mr. E. T. Atkinson (Ind. Mus. Notes, Vol. I., (/>/. 4), p. 209) an insect reported to have been obtained from Kangra. 625. DEPREDATIONS AND REMEDY. The remarks already offered (para. 623) apply with equal force to this insect. Kangra may be said to have but two pests of any consequence, the present one and the " bar ota or basket-worm (Amatissa COnsorta). Neither should be viewed lightly, since it is possibly an accident, more than anything else, that they have not as yet assumed gigantic proportions. In the Journal, Agri.-Horticultural Society, particulars will be found of a treatment with kerosene emulsion that seems to have been fairly successful. If only a slight attack exists that insecticide may suffice and should of course be tried, but no scale insect ought to be allowed to gain ground while experiments are being made with different methods of treatment. It would in that case be preferable to sacrifice a few bushes than risk a large number. 74. (c) Aspidiotus dictyospermi, Morgan, var. arecae. [ Cockerell. (Reg. No. 89.) 626. HISTORY. Among the specimens furnished by Messrs. Shaw, Wallace & Co., from Holta, I found three leaves of what appear to be tea. These had the upper surface completely covered with a scale insect quite different from the previous species, This, Mr. Green has THE KANGRA SCALE INSECTS. Wrongly known as a species of Lecanium. The Basket worm. Con/, ^oith para. 372* Another Kangra Scale Insect. 324 Report of Investigations in Assam Rhynchota (Coccidae). been good enough to inform me, is a species that he has hitherto found on rose stems, ivy and Cycas revoluta. In the Kangra sample it occurs on the leaves, not on the twigs, but unfortunately I am not sure of these leaves being tea. In some respects they are remarkably like tea, but are too thick and leathery and the veins too far apart and too square to the mid-rib. If it is tea, it must be a strikingly peculiar hybrid. 75 (c) Fiorinia fioriniae, Targ. Tozz. (F. palmae, Green : F. camelliae, ComstocTc, Agri. Report, 1880, p. 529). References. Green, Coccidcz of Ceylon, pp. 94-95, PI. XXV I. (Reg. Nos. 33 88, 118.) 627. HISTORY. Mr. Green writes me that, since the date of publica- tion of the account of this insect (in his Coccida of Ceylon), he has lately found it on tea, but confined to low jat China bushes. This is without doubt the most prevalent of all forms of scale-bug or scale-louse in Assam, and is by no means unknown in Kangra. I have no personal acquaintance with the other tea districts of India, but should be much surprised were it not found in these as well as in the localities I have personally explored. It was certainly not found by me to be confined to \o\vjat bushes, though I never saw it on any plant that did not mani- fest the same unkempt and dirty appearance. The leaves were invari- ably coated with dust, especially the under surfaces. This long, narrow and brown scale-louse might in fact be said to be buried in the mud adhering to the leaf. It lives on the under-surfaces of the leaves, and may sometimes be seen in hundreds on the same leaf, sufficiently numerous to give it a dirty brown appearance. I presume the mud may possibly adhere to the leaves, in consequence of the sugary exudation produced by the louse, but whatever be the explanation of the circumstance mentioned, it is so invariably the rule as to hardly escape notice, and must greatly interfere with the respiration of the leaves. The plants are sickly and unproductive. The insect may be described popularly as a long narrow chestnut-coloured scale, with a ridge down the middle. It shows very frequently smaller scales escap- ing, as it were, from the top and near one extremity. 628. DEPREDATIONS AND REMEDY. After what has been said, it need hardly be added that this pest (insignificant though it may appear to the planter who may find here an affected bush and there another), is a dangerous insect to neglect. Mr. Green has kindly furnished me Tea Pests and Blights. The Scaley Bugs or Scale Lice. Oct. 1895, p. 328 ; rt Insects and with a specimen showing the scale parasitised by a fungus. His remark on the same may be here quoted : " If this Coccid should become troublesome in the Indian tea districts, it would be easy 1o introduce this fungus if it does not already exist." The fungus is not at present found in India so far as my experience goes, and it certainly would be worth while to obtain a supply of the fungus. But, in my opinion, a bush, once badly attacked by this scale-louse, will never recover. It is necessary either to collar prune down to the ground, and to instantly burn all the prunings, or then to fire the bush first and prune later as may be required. The advantage of firing the bush as it stands is that the pest is killed without any chance of a wider distribution being afforded through shaking, on carrying away the prunings. 76. (a) Chionaspis theae, Maskell. WHITE TEA-LEAF LOUSE. References. Maskell Ind. Mus. Notes, Vol. II. (pt. /), p. 60 i-Green, Insect Pests of the Tea Plant, 12-18; Ind. Mus. Notes, Vol. I. pp. 188-igo ; II., 59, 60, ; 68 ; III., 25 ; (pt. 4) 60 ; IV, 42 ; Journ, Agri.-horti. Soc. Ind., Vol. X., Proc., 2$th Oct. 1 Bamber, Chem. and Agri. Tea, 252 ; Cotes, (in part) Mites, etc., p. 39* (Reg. Nos. 26, ug ; Tubes Nos. 206, 268 : botanical specimens No. 629. HISTORY. The first mention apparently of this pest on Indian tea is in connection with the specimens procured from Kangra and sent to Mr. Maskell for determination. Mr. Green, as he himself has pointed out, made the unfortunate mistake of viewing the female scale of C. biclavis, Corns/., and the male scale of C. exercitata Green, as constituting one species. In consequence he called this " the tea bark louse," whereas the species lives entirely on the leaves. Mr. Cotes followed the above error, so that his article is a combination of the peculiarities of this and the next species. 630. The male scale will be recognized as little patches or colonies of white waxy flakes, neatly arranged on the leaves of the tea plant The very natural difficulty is at once suggested, on viewing these colonies, of the improbability of the female being able to reach the leaves in order to deposit the germs of these male scales. As a matter of fact, however, the puparia of both sexes are to be seen on the leaves. The male scale ( or puparium ) may be expressed popularly as a small yellow pellicle placed at the extremity of a structure that consists of three white waxy ridges, parallel to each other. The THE WHITE Tollslf WHITE TEA- LEAF LOUSE. Con/, with para. 514. Colonies of White Waxy Flakes. 326 Report of Investigations in Assam Hemiptera (Coccidae). female puparium is very much larger ( J^th inch long), is of a light brown colour, in shape pyriform, flat, with a brownish yellow pellicle at the narrow extremity. The colonies of male puparia are very plentiful, the female ones comparatively rare and dispersed over the leaves. The adult male has not as yet been discovered. Mr. Cotes makes the very practical remark under this species that " In all scale insects the question of dispersion is an important one for, owing to the adult female being stationary, it is only the newly hatched larvae which are able to travel from bush to bush, and thus spread the evil. It is important, therefore, to ascertain at what period of the year the larvse emerge and the extent to which they are liable to be carried by the winds. " 631. DEPREDATIONS. So far as is known, this species is confined to the leaves, the colonies of male scales ( or puparia ) being on the upper-surface, and the female very often below. They must of course abstract a large amount of sap from the plant, but, so far as I could discover this insect, though common here and there in Assam, nowhere exists so abundantly as to cause material injury ; I have recently, however, received from Darjeeling twigs of tea with the leaves almost white from the numerous colonies of this louse. 632. REMEDY. It might be greatly mitigated by sending out children to strip the leaves, seen to bear colonies of male scales, through the fingers. That would no doubt kill the males and very often the females also. Should the pest ever assume serious proportions, it should be treated in the same manner as for all other scale insects. 77 (b) Chionaspis biclavis, Comst. THE TEA BARK LOUSE. (Reg. No. 120.) 633. HISTORY. So far as I can discover, this species does not exist in India. At Patalipam I found the barks of manybushes cracked and splitting off in the manner peculiar to this species, but I could not be sure that I had found the scale. Mr. Green has been good enough to furnish me with a type specimen. His remark recorded on it may be here quoted : " A very inconspicuous species the scales looking like small blisters on the bark. Often present in large numbers and responsible for hard wood and short flushes." This is the insect described in the greater portion of Mr. Green's Aspidiotus these (Insect Pests of the Tea Plant} and, as already Tea Pests and Blights. 327 Tea Leaf and Bark Lice. remarked, it is the female insect of Mr. Cotes' account of Chionas- pis these {Insects and Mites, etc.}. 78. (a) Chionaspis prunicola, Mask., var. these, Mask. 634. This has been described as a tea pest in the Indian Museum Notes ( Vol. IV., p. 60), but no locality has been recorded for it. 79- (b) Orthezia insignis, Dougl. (Reg. No. 125.) 635. This very troublesome pest seems to have been introduced into Ceylon on ornamental plants. Mr. Green informs me that it occurs on Lantana, (a plant plentiful in some parts of Assam) and that it spreads to the neighbouring tea. To the naked eye it looks like little particles of white wax. It is a dreadful scourge and must be dealt with promptly should it appear. So far as I am aware however, this pest has not as yet found its way to tea in Assam. Mr. Green writes me that he has met with the pest crowding into the young shoots He adds that the infested area in Ceylon has been fired and the pest apparently thus exterminated. 80, (b) Pulvinaria psidi, Mask. (Reg. No. 126.) 636. Mr. Green has been good enough to furnish me with a sample of this insect which, he says, is sometimes present in injurious numbers on individual tea bushes. I have not come across it on tea in India. It might be described as looking like small irregular white patches of paint on the under-surface of the leaves. 81. (c) Eriochiton? nov. sp', (Reg. No: 86 ; botanical specimens No. go6o.) 637. HISTORY. On the igth of April 1897, Messrs. D^enport & Co. forwarded, for examination and report, samples of * pest which had appeared in The British Darjeeling Tea Company's Gardens, Dar- jeeling. The leaves on their uppersurfaccs were densely coated with a black sooty fungus, and on the un^ersurfaces, more especially near the midrib, bore numerous long pure white scales, that had a tuft of waxy hairs arranged along a medial ridge. This seemed to me a remarkably interesting and possibly new Coccid, so that I took steps to obtain expert opinion on it. 638. Mr. W. T. Thiselton Dyer, Director of Kew Gardens, was good enough to inform me that Mr. George Massee had identified the fun- gus as Capnodium Footii, Bcrkl. & Desmoz. Mr. Dyer wrote that INSI 328 Report of Investigations in Assam Rhynchota (Coccidae ). ERIOCHITON Con/, ivith paras. 46 (2), 837-8. Soot Blight. Allied to the Coffee-bug. this fungus had not previously been recorded as met with in India, but that it was common on insect-infested Camellias in cultivation, and also blackened the lime trees (Tilia), appearing in association with the honey-dew aphis. 639. A sample of the Coccid was sent to the British Museum, the result being that Mr. Chas. 0. Waterhouse referred me to Mr. Green, of Ceylon, as the person most likely to be able to name the insect, but he added there was nothing the least like it in the British Museum collection. I had, at the same time, furnished a sample to Mr. Green along with the suggestion that it might prove a species of the ALEURODID/E. Mr. Green's reply was as follows: "I believe this to be a true Coccid, not an Aleurodid. The examples consist of the empty puparia from which the winged males have made their escape. The few large waxy patches are the remains of the scales and eggs, but none of the adult females could be found. A single mutilated half-grown larvae shows it to be LECANIID and apparently belonging to the genus Eriochiton (Con/. E. cajani, Ind. Mm. Notes, Vol. II. (No. /), p. d/.)" It seems probable that the author of Notes on Tea in Darjeeling (p. 5 3), may be alluding to this blight under the heading "Soot Blight." " It is a small insect with a sooty covering, which makes the trees look fearful and stops all flushing. Luckily, this is not com- mon, and, as a rule, only one or two trees will be found on a garden." 640. DEPREDATIONS AND REMEDY. Mr. Sproull, who had furnished the samples, wrote in his letter of the i4th April, " I plucked these leaves from a tea bush in Kigali (at an altitude of 4,500 feet) this morning. There are several others similar adjoining. The leaves had quite a b^ck appearance, and on examining them I found the lower sides covered with an aphis. They certainly do harm to the bushes ; these bushes were in good health quite lately, and other bushes around the ones attacked are looking and flushing well, while the attacked ones are black and no flushing coming out of them. I have never seen tea bushes so attacked before, although I have seen these lice-like insects on Poinsettias." As this is probably a new Coccid to India could it have been introduced on ornamental shrubs, such as the Poinsettia (Euphorbia pulcherrima) ? 641. In the correspondence that ensued, I stated that the insect was certainly not an aphis, but a much more dangerous pest, one of Tea Pests and Blights. 329 The Scaley Bugs of the Tea Plant. the scale-bugs, perhaps, not very remote from the Coffee-bug. Washing with kerosine emulsion might stop it ; but, if only a few bushes are affected, I would recommend, as more effectual, that they should be at once fired. If below each bush and amongst its branches a few handfuls of dry straw are placed and then ignited, the sudden flame produced will char all the leaves and twigs and completely eradicate the blight. Only the very sickly bushes will be thereby killed. The flushing will be retarded for a month or two, but the cure will be complete. As a rule, it is not wise to fire bushes much after March. If later than that, the shock is very much more severe, and the flushing may not be resumed before six or eight or, perhaps, eighteen months. But even a delay, such as I have indicated, would be preferable to the bushes being killed and the disease extended over the estate. Diseased bushes of course suffer more severely from being burned in the manner proposed than healthy ones accidentally fired, but if even 50 per cent, are saved and a troublesome disease eradicated, the gain is distinct. Other less severe methods of treatment may possibly give a higher percentage of bushes saved, but they involve the risk of the disease spreading or even being artificially distributed in the act of cutting down or of constantly visiting and handling the bushes. In a subsequent letter (26th April), Mr. Sproull wrote, " there were about a dozen bushes attacked, the leaves of which were all black and appearing as if they had been dusted with soot. " " I will carry out your suggestion as to burning. " On the Hth May, Mr. Sproull replied, to my request for more specimens that he was sorry he could not supply any as the bushes had been burned and no more of the blight could be found in any other part of the garden. 642. OntheiQth July Mr. Sproull informed me that a fair per- centage of the bushes that had been burned, were again under leaf. Many of the bushes seem to have been so badly attacked with the scale that they were nearly dead before being fired. Speaking of the advantages of firing circumscribed plots of tea, badly affected by blights, Mr, Sproull adds, " I do not think anything better than fire^ It is cheap, handy, always available. One knows from experience how great a quantity of fire it takes to kill a bush as seen when abandoned portions are again reclaimed or along the edge of cultiva- tion after being scorched by jungle fires. " INSECTS. Firing Reeom- meneded. Con/, with paras. 649, 767-8, 774, 777-8. Percentage. Result. 33 Report of Investigations in Assam Hemiptera (Coccidae). 82. (b) Lecanium viride, Green. THE GREEN-BUG. (Reg. No. 121.) 83. (b) L. nigrum, Nietner. THE BLACK-BUG. 84. (c) L. coffeae, Walk. THE BROWN-BUG. (Keg. Nos. 95 and 122.) 643, I propose to deal with these three insects conjointly, since, so far as I have been able to discover, only one of the three, viz., L. coffeae, occurs on tea in India. Mr. Green tells us that green-bug, though it killed out the coffee in whole districts, has fortunately not seriously attacked the tea. The brown-bug, on the other hand, he says, is common on the leaves and stems of tea, and the black-bug, though originally described from coffee, is now seldom seen on that plant. Mr. Green makes no mention of its having appeared on tea. In the Indian Museum Notes ( Vol. /. {No. 2), pp. 113-122) will be found a useful paper on these three species. It reprints, by permis- sion, Mr. Green's pamphlet " Observations on the Green Scale-Bug," and gives his comparative series of drawings in illustration of the various stages in the life of each of these dangerous pests. The article in the Museum Notes furnishes also the particulars and results of the experiments with kerosine emulsion as a cure for bug. 644. Of the three species, L. viride has hitherto proved the most dangerous, but fortunately has not, so far as is known, found its way to Assam if indeed it exists on the tea anywhere in India. References. Gardner in Hooker's Journ. Bot., Vol. II. (1850), pp. 353- jfio; //., pp. i-g ; PI. XII. (possibly L. coffece and L. ntgt jointly dealt with and figured in this paper) , Nietner, Co rum con- offee Tree and its Enemies ; Green, Observations on the Green Scale-Bug ; Green, Insect Pests of the Tea Plant, pp. 81-88,- Bamber, Chem. and Agri. of Tea, 252 ; Ind. Mus. Notes, Vol. I., 49, 113, 122; II., 168; III.,(pt.4) 18 ; IV.(No. i), 9-10; Cotes, Insects and Mites, etc., 41-43. 645. HISTORY. So far as I know, neither of the bugs here dealt with had been found on Indian tea prior to my discovery of L. coffeae in North Lakhimpur. I found it on two occasions, but both on the North bank of the Brahmaputra. Samples from these collections were sent by me to Mr. Green for favour of examination, and the Tea Pests and Blights. 33' The Scaley Bugs. following passage from his reply may be usefully given: "Your sample No. 95 shows the adult and immature stages of Lecanium COffeae, Walk. It is occasionally very injurious to individual tea bushes here, but only on such as are sheltered from rain. Many of the scales supplied by you have been killed by a parasitic fungus which has completely destroyed the tissue of the insects and developed into small orange-coloured nodules upon the twigs." The specimens collected by me were not found under shade in any way, they occurred in the middle of flat expanses of tea. I do not even think there were trees near by, but unfortunately I did not make a record in my diary on that point. The one set of specimens was collected at Dirpai on the banks of the Subanseri river, but in association with Ceroplastes myricae. .The other at Patalipam, and this was the sample parasitised in the manner men- tioned by Mr. Green. 646. DESCRIPTION. The full-grown female scale in my Patalipam collections is almost globose, is of a pale chestnut brown colour and somewhat polished. When younger, it is an oval scale with a strongly marked longitudinal ridge and two transverse bands. The larvae are active pale canary yellow or almost lemon yellow crea- tures that move fairly actively for a time. Like all the other species of this genus, they have an anal sinus with two short hairs arising within it. The male has a smaller more elongated or linear scale which never becomes globose, and, when mature, is almost transparent revealing the pink chrysalis which in time gives forth its minute winged red fly. The insect found at Dirpai may possibly prove a new species closely allied to L. coffeae, and I venture, therefore, to give here the description of it from my diary : In the mature state these are tortoise-like creatures. They are pale straw-coloured, when young, turning to brown and mottled with a darker shade. In shape they are elliptic in outline, smooth with one longitudinal fold, and two transverse horizontal ones over the globose body. From beneath the mature bugs, larvae were seen to escape. These are so small, when they first emerge, that they can hardly be recog- nized by the naked eye, and even, when localized by a lens, are difficult to see. 647. The larvae are remarkable creatures, pale straw-coloured, al- most obcordate in outline, the anal extremity being bifid, and having Parasitised by a Fungus. Associated with a Wax ! Insect. Possibly New Species. 332 Report of Investigations in Assam Rhynchota (Coccidse). LECANIUM COFFEE. Proboscis Produced on becoming Fixed. Black Fungus. Bushes Discontinue Flushing. Fire Recom- mended. a thickened elongated tail-like structure within the sinus and two long anal horns on either side. The anterior extremity may be said to be broad, somewhat rounded with a minute acuminate beak. The body gives indications of being articulated into eight sections, and carries bifid hairs on the margin of the flattened wing-like ex- pansion, corresponding to these sections. The eyes are large black situate behind the point of origin of the flapper-like large antennae. These are seven-jointed and very hairy. I could see no proboscis though I looked at many larvae, but their active life is so short that they may be said to become fixed before one can pick them off the twigs. They are curious trilobite- looking creatures that crawl from beneath the margin of the mother bug, advance for about a quarter of an inch from the parent, and in a few minutes loose the power of locomotion and become fixed. The proboscis is then produced from below the body, and inserted into the plant. Some of the larvae seen were a little more elongated than the others, and had two pinkish bands across their bodies : these appear to be the males. These larvae grow readily, and on becoming fixed the legs and flapper-like antennae disappear, the eyes become obscure, as also the semi-articulated condition of the body. They then swell up in shape, becoming almost globose, lose entirely the form described, and assume the adult condition. 648. DEPREDATIONS. On both occasions where I met with the brown-bug in Assam, my attention was attracted to the bushes by their black sooty appearance due to the upper-surfaces of the leaves being coated with a black fungus, apparently the same species as occurs in association with the bug in Ceylon. The bug lives on the under-surfaces of the leaves and on the twigs and shoots. The female insect, on its becoming fixed, inserts its delicate hair-like proboscis and sucks the juices of the tea. The plant is thus gradually impoverished and soon shows the extent to which it is suffering by discontinuing to produce flushing shoots. 649. REMEDY. This pest must be treated in exactly the same man- ner as with all other scale insects. Whenever seen, the bushes should be carefully brushed with kerosine emulsion. Should the disease be found securely established and be giving indications of expanding, rather than risk the larvae being blown by the wind or carried by the clothes of the coolies far and wide, fire the plot. It is more economical Tea Pests and Blights. 333 The Scaley Bugs. to lose the bushes than to risk a wide distribution of this or any other scale-bug. 85* (b) Lecanium formicarii, Green. 650. Through the kindness of Mr. Green, I have had the pleasure to receive a specimen of this insect. I did not come across it in Assam, but mention it as a pest that may likely be found. It occurs in Ceylon within the mud hives formed by the ant, Cre- mastogaster dohrni. A closely allied ant is common in Assam, and doubtless, when these mud hives are more carefully examined, this or an allied Lecanium will be found within them. The ant imprisons the scale insect in order to have a convenient supply of sugary fluid. 86. (c) Lecanium, sp. nov. (Reg. No. 124, Tube No. 293.) 651. From Mr. J. A, Thomson, of Ligri Pukri, Nazira, Assam, I had the pleasure to receive a most interesting species of Lecanium. Specimens of this were forwarded by me to Mr. Green who has replied : " This is a handsome large species of Lecanium which I believe to be quite new and which I propose to call L. watti." The scales are about J inch long and are of an oval shape and a thin cartila- genous texture. The scales are found attached to the shoots and completely encase the twigs, while the leaves are covered with the soot-like fungus that accompanies most species of this genus. This could be a formidable pest, but fortunately it ' seems to be very rare. 87. (c) Ceroplastes myricae? Linn. (Reg. No. 96, botanical specimens No. 11961.) 652. HISTORY. On reaching North Lakhimpur, one of the first ques- tions I was asked was, whether I had come across the lac {lakh) i as a tea pest. On being taken to a plot of bushes in Dirpai with this disease on them, I fully appreciated the applicability of the description of lac pest, for every twig was seen to be completely encrusted with a thick resinous substance that I soon saw was not lac, though by no means a distant relative of that insect. It was a species of Ceroplastes that Mr. Green has been good enough to identify for me as Cero- plastes myricae? Linn. SCALE 1SECT3. Found with in Ant Mud Hives. Con/. ii-itU para, 497. 334 Report of Investigations in Assam Hemiptera (Coccidae). CEROPLAS- TES MYRIC^: found on Tea and also on a Cycad. Associated Fungus. 653. DESCRIPTION. It was with considerable astonishment that I proceeded to examine this most curious pest new entirely to my already large list of insect enemies to the tea plant. I was told that, although it had nowhere appeared to an alarming extent, it was well known in Upper Assam, especially on the North bank. I had not come across it before, and was not a little surprised that the Cero- plastes was invariably associated with the Lecanium that I have provisionally described above, under the same specific heading as given to my previous collections, viz., Lecanium COffeae. Speaking of the fairly common and significant association of two scale insects together, I may add that the other day, in Calcutta, I came across Ceroplastes myricse growing on the leaves of a Cycad, but in this case it was associated as Mr. Green tells me with Aspidiotus orientalis, Newst. This curiously interesting further discovery sug- gests the not very improbable inference that Ceroplastes myricae, as a tea pest, may have been derived from the very frequently seen Cycads in the planter's flower garden. 654. Not only were the two LECANIIDS mentioned, invariably found together on every tea bush examined by me (affected by this pest), but they were also accompanied with the black sooty fungus so common on tea infested with scale-bugs. It perhaps is hardly necessary for me to attempt a detailed description of this insect, but the following observations taken from my diary may help the planter to recognize the pest : These waxy-looking bugs may be said to be pale pink, sea-anemony-like creatures that have on either side of their waxy encasement two wavy white folds. The encasement may be spoken of as comprising an outer more or less flattened rim, with a central globular portion, so that in main shape the waxy structure is not unlike the Parsi felt-hat. At one extremity, and situate on the outer rim, there are three circular bodies, two right and left (which may be spoken of as () () and one in the middle (a) the anal orifice. While, right on the summit of the globular central portion, there is a crater-like depression of a pure white colour (c), and in the centre, what I take to be, a breathing tube. The anal orifice opens every now and again, and a bifid deep purple structure pro- trudes. From this a little fluid is first blown into a miniature bubble, then bursts and is dispersed as dew. The bifid organ is withdrawn and the anal scales closed. The structures (a), () and (c) are Tea Pests and Blights. 335 Wax Insects. portions of the larval test that protrude through the waxy encasement of the adult female. 655. Mr. Green to whom I sent samples of this very interesting new tea pest, was good enough to send me some particulars, regarding the life of the insect. " A longitudinal section," he says, " through the in- sect would show the body completely incased by a waxy deposit. The spiracles, two on each side, open on to the under-surface, and their position is marked by opaque white wavy bands. After gestation the ventral parts of the body shrivel up and the cavity becomes filled with the eggs which in due time hatch out, the larvae escaping from beneath the dead body of the parent." 656. I may here add, by way of conclusion that the insect seemed badly parasitised, since many of the waxy encasements were per- forated, no doubt owing to the escape of some ichneumon-fly that during its larval existence had lived on the scale-bug. The larvae of a very small orange-red-coloured ladybird beetle (without any markings on its wing-cases) were also seen to be actively at work. These were very energetic little creatures, and from the formidable- looking hairs with which they were clothed on the back seemed as if they might also be poisons (Conf. with 2nd. Mus. Notes, Vol. IV., 27-28). After the scale-bugs are killed or have died on one part of the bush the black fungus invades the shoots as well as the leaves, so that the advance of the pest from branch to branch and twig to twig may be traced by the black coating on the portions of the stem that have been abandoned. 657. DEPREDATIONS AND REMEDY. It goes without saying that, were this lac-like scale-bug to become general, it might threaten the very existence of the tea plant. Hitherto it has appeared spasmodically, a clump of two or three bushes being killed, before it had been re- cognized. Fortunately it is easily seen, and its depredations so self- evident that the bushes are invariably cut down and destroyed the pest being thereby in most cases stamped out. I have repeatedly said that it is impossible to foretell when a comparatively harmless accidental visitation of this kind, may suddenly assume gigantic proportions. It is the duty of the tea planter, therefore, to avoid the dangerous atitude of smiling at the idea of a bush which shows scale- bug being viewed as serious. Thelarvse of these pests are so minute that they can be blown far and wide by the wind, or carried on the wings 3TS. Enemies. Possibilities. 336 Report of Investigations in Assam Rhynchota (Coccidae). CEROP- FLORIDE E NSIS Ri, lodlan Wax. and feet of insects that come to feed on the sugary exudation. In one night from a nucleus of two or three bushes miles of tea may be in- vaded and the life sapped out of the bushes before the evil is re- cognized. The story of the Ceylon coffee-bug must never be lost sight of, nor its warning neglected. Many of the scale insects, like Ceroplastes myricae, are so protected by their waxy coating, or the hard shell-like structure of the scale, that insecticides cannot reach them. They may be mitigated or even killed by insecticides, however, after a careful study of their life histories has been made. The larvae rapidly succumb to kerosine emulsion and a washing or spraying with the fluid, repeated at the periods of each fresh brood of larvse, would in time no doubt eradicate the pest. The danger is that in the intervals of the insecticide treatment, swarms of the lame may have been allowed to escape. In cutting down the bushes the stroke of the axe may distribute the larvae, and they may be shed over a large number of healthy bushes by the prunings being carried away by the coolies. It will, therefore, be seen that the treatment I have recommended, -viz., to fire the bushes, has much to be said in its favour. A distinct percentage of the bushes are saved, the pest is completely eradicated, especially if the one or two unaffected bushes around the diseased clump, are also burned. 88. (c) Ceroplastes cerifera, Anderson. THE INDIAN WAX INSECT. (Reg. No. 02.) 658. HISTORY. The large irregularly shaped white waxy tubercles of this insect (often \ inch in size) are occasionally to be seen on tea, scattered here and there along the branches. These are so unlike insects that, unless the wax be dissolved off their bodies, they can hardly be recognized as such. This species nowhere occurs in sufficient abundance to justify its being classed as a tea pest, but it nevertheless is fairly common. I found it in a dozen gardens or so in Assam, and have samples sent me from Darjeeling. 80, (c) Ceroplastes floridensis, Comst. (Reg. No. 93 .) 659. HISTORY. This curiously shaped pink-coloured wax insect is fairly common on tea in Assam and Darjeeling, and, Mr. Green tells me, it is frequent in Ceylon, " but not in injurious numbers." It will be generally seen on the upper surface of the leaves and in its young Tea Pests and Blights. 337 Wax Insects. state, when not much larger than the head of a pin, is a very prett star-shaped object. 90. (a) Carteria decorella, Mask. 660. In the Indian Museum Notes, Vol. IV., pp. 38-60, particulat will be found of this insect which had been sent to the India Museum as " attacking tea and forest trees in Northern India." did not find it on the tea in Assam nor in Kangra. THYSANOPTERA. LXV.-The Thrips. 661. It would seem probable that there are one or two species o this very remarkable assemblage of insects found in Assam as tei pests. I was unable to devote sufficient time to their study to enabl me to learn any very definite particulars regarding them. They ar< very minute insects and are seen on the under sides of the leaves especially on bushes overcrowded or under shade. The larvse ar pale lemon-green coloured and are less than -Jgth of an inch in size Small active longish creatures that run about all over the leaf, or tak( shelter alongside of the midribs or veins, on being disturbed Occasionally they may be seen to have formed a minute web below which they repose. The antennae are thrown back over the head and between the large crimson-coloured eyes. The adult insects differ from the larvae in being almost black, and in having two pairs of long narrow fimbriated wings one over the other. In other respects they are very similar to the larvae. 662. The mouth might be described as a short sharp rigid pro- boscis composed of a pair of long bristle-like mandibles which they employ in perforating the leaf. It seems likely, however, that they should be regarded more as chewing the tissue, than as sucking the juice. This much, however, is certain, they cause large irregular patches of the leaf to become discoloured, and these sometimes even show through to the upper surfaces. On one or two occasions I found Thrips so plentiful, on a plot of tea described as "crinkly blight," as to suggest the desirability of special enquiry. It is well known that the European species of Thrips do the greatest possible harm to corn, potato and other crops. The larvae push their way into the buds and destroy the grain. It thus seems possible that they may 1 THRIPS. epredations. Crinkly Blight. 338 Report of Investigations in Assam Thysanoptera. THRIPS. Stem distorted in Bud. Con/, ivith para. 691. penetrate the buds of the tea and cause the loss of vigour and discolouration attributed, on the buds unfolding, to other insects such as the green-fly. I only offer this as a suggestion, however, and mainly in order, if possible, to arouse some attention to the subject of the forms of Thrips found on tea. I believe it highly probable that these minute pests may be found responsible for a greater amount of damage than we have any knowledge of at present. Tea Pests and Blights. 339 Termites or White-ants. CHAPTER XIV. PSEUDONEUROPTERA. LXVI. Termitidce or White-ants. 663. In consequence of a letter received from the Secretary, Indian Tea Association (2ist February 1896) the chapter on White-ants was prepared in advance of the rest of this report. Copies were issued to a selected number of tea planters, and in due course a few also found their way into the public press. In consequence, my opinions arid suggestions on this much-debated subject, have been freely discussed. The remarks, which follow, may, therefore, be regarded as a revised edition. I may also add that, in connection with enquiries into the subject of Reha fibre, I had recently occasion to conduct an exploration of some of the districts of Northern Bengal and of Lower Assam. The opportunity thereby afforded was taken advantage of in verifying my 'previous observations, as also of testing the value of the numerous corrections and additional information that had been brought to light, through the private and public discussion of my views and recommendations. One practical result may be said to have been brought about, namely, the confirmation of the opinion I had ventured to urge, viz., that we have more than one species of White-ant in India. During my more recent investigations I collected sufficient material to justify the statement being now put forward, that we have at least three, if not four, different species of Termites, and it seems possible, were India, as a whole, explored (from this standpoint), we might even be able to add a cipher to the figure named without overstating the specific diversities that exist under the generic name of " White-ants." 664. The three or four forms recognized by me differ in structure, in habit, and in food. Unfortunately the state of the collections at the Indian Museum has deprived me of the opportunity of having my specimens compared with standard types and of assigning to them their scientific names, if such e*ist. Indeed remarkably few entomologists have studied the Termites, so that, for the present, I must content myself with such popular descriptions as I ventured to advance in the original version of this chapter. But let me urge that WHITE-ANTS. The Present Chapter a Revised Edition. Practical Result. Different Forms of White-ants. 340 Report of Investigations in Assam Pseudoneuroptera (Termitidae).' TERM! TAPrfOBANE? Different Forms. WHITE ANT. Con/. tHt para. 46 (16). Castellated White-ant Hives. it is of vital importance to any progress in the practical aspects of the study of White-ants, i.e., their eradication, that my statement be accepted as correct, viz., that we have in India many forms of White-ant, some that will ordinarily eat only dead vegetable matter, and others that will attack and kill plants. The contradictions that one meets with in the literature of this subject proceed exclu- sively from the possibility being overlooked or ignored of there being White-ants and White-ants. The three or four forms to which I more especially desire atten- tion, as met with in Assam tea gardens, may, however, as a matter of convenience, be discussed under the only scientific name hitherto applied to them : 9 1 - (a) Termes taprobanes, Wlk. THE CASTELLATED WHITE-ANT OF INDIA. References. Report of Committee of Enquiry on the Ravages of White-ants in St. Helena, 1864; Scott in Journ. Agri.-Hort. Soc. Ind., Vol. III. (1871), pp. 42-47 ; Col. Money, Essay on Tea I. c., p. 219 ; D. D. Cunningham, Fungi in White-ant Hills, Journ. Agri.-Hort. Soc. Ind., IV., pp. 51-5.3, also Proc., 2oth May 1875, xvii ; Vol. IV, Ravages' of, on 'lea, Proc., 2th Nov. 1880, p. xxxvii ; a 2nd Dec. i88r, p. Ixiii ; Vol. VII., Proc., Woodr&w on Corrosive Sublimate as a cure, th Jan. 1883 ; Proc., 31 st Oct. 1884, p. cxi ; Proc., asth Nov. 1885, p. clxxxvii ; Vol. VllL, Proc., t$th Sept. 1886, (Liotard on Neem Leaves as a cure), p Ix ; Cleghorn on White-ants, Vol. X, Proc., 2oth May 1896, pp. 526-533; Tea Cyclopedia, 52-53 ; Green, Insect Pest of the Tea Plant, 93-98 ; Ind. Mus. Notes, Vol. I., 63-66 (Chutia Nagpur White-ants eat the roots), II., 772 ,- ///., 23 ; IV., 36, 102-104; Cotes, Insects and Mites, 46-48. 665. Different Forms. The common species of Bengal, we are told, bears the name of Termes taprobanes, Wlk. Viewed from a popular standpoint, and having regard more to their modes of life and methods of effecting destruction, than to their structural peculiarities, they would seem to be widely diversified. This will at once be exemplified by the mention of one circumstance. The castellated mud nests (often 5 to 10 feet in height) so commonly formed by the white-ants in Bengal, are not apparently constructed by the white-ants of several other provinces in India, and this fact is possibly accountable for by the supposition that some forms of white- ants live in cavernous excavations below, others in superficial structures above ground. Be that as it may, white-ants are known to abound in localities and positions where readily recognizable white- Tea Pests and Blights. White-ants. ant nests are not found. In some cases they exist in vast colonies, in others as very small and isolated communities. How far these may be but stages in the life of one species is one of the obscure points that urgently demand solution. According to my observations there are in Assam, for example, at least three, if not four, different forms of white-ants : /j/.A large species that constructs the immense (non-castellated) rounded ant-hills which, when levelled and brought under cultiva- tion in the garden, are said to constitute barren patches. This might be regarded as the species that abounds in the jungles and forests, more particularly in association with the bamboo. It is often found in aggregations of hillocks, covering a more or less extensive area, and giving to the clearances of such tracts a curious undulated, almost warted appearance. This species does not ap- preciate association with man and dislikes the direct action of the sun. It consequently abandons its hillocks very rapidly on the forest being cleared for tea estates. It seems to live exclusively upon dead timber. 2nd. There is the village and cultivation-loving species that forms large castellated hillocks of mud. This will generally be found on clay soils, but only when above inundation level, hence it chooses the strips of high land around cultivation or on the homestead lands. This very possibly originates by a pair of winged ants (male and female) finding their way into the ground and existing for some time in subterranean caverns. But as the workers and soldiers of the new community (born from the eggs laid by the young queen) increase in number, the clayey ingredients of the soil are carried above ground, and the castellated hillock gradually formed. Pas- sages under ground, that extend for marvellous distances, are also formed, but the combs and queen cells of the hive are, as a rule, placed above water level. There would, however, appear grounds for suspecting that the very similar-looking termite that invades human dwellings is in reality a distinct species from the castellated white-ant of cultivation. If they be the same, then it is a species that possesses the power of living under widely different conditions. For the present I accept the usual opinion that they are the same, and, therefore, this species may be said to live on dead wood, furniture, leather, paper, cloth in JVHITE-ANTS: FORMS OF. Round Hillocks In Jungles. Con/, with paras. 68O- 696. Castellated Hives in Fields. Con/, with para. 167. 342 Report of Investigations in Assam Pseudoneuroptera (Termitidae). TERMI TAPROBA Surface Hives. Con/, with page 367. Very Combustible Under Ground Con/, with page 367. "Ratters. ' fact any dry animal or vegetable matter. But by encasing dead portions of plants with mud it not only eats these, but extends the destruction to living tissues. (Reg. No. 7.27.) jrd.A. rather long and very thin species of white-ant that constructs hives not larger, as a rule, than an ordinary foot-ball. These occur over grass lands, the hives or nests being found half under ground. They may be kicked out, and, while full of white- ants, will be found to have no deeper connection in the soil. Some- times these hives may be seen to consist of reeds cut to a desired length, assorted parallel, then cemented together.* At other times the hive consists throughout of a black vegetable (non-earthy) sub- stance, extremely hard, and so firmly compacted that the hives may be dashed on the ground with great force and still remain entire, or nearly so. The material of which they are constructed, it may be added, is very combustible. In a garden visited by me the other day, hives of this nature were being collected in scores daily, piled up in heaps and ignited an excellent method of disposing of them. When cut open they may contain male and female ants in the imperfect winged state, and neuters that are clearly the warriors and workers of the community. But though I broke open many hives, I never came across what I could regard as the queen of the community. So far as I have been able to ascertain, this species lives very largely on green vegetable matter. (Reg. No. 129.) 4th. Lastly, there is a small white-ant that lives under ground and particularly among the roots of bushes or within the decomposed branches above ground. This excavates oblong caverns that might be said to range from i foot to 2 or 3 feet in size. One might say that it would be next to impossible to dig a trench any -where in Assam without exposing several of these remarkable excavations, the interiors of which are always more or less filled up with a curiously reticulated structure that might be compared with the combs of a bee-hive. Similar combs exist in the castellated hives. The form that I desire to draw attention to in this paragraph, might be designated the White-ant of Agriculture. Mr. Whigham has suggested for it the expressive name of the " Raider White-ant." It lives on the roots and lower shoots of living plants (on the tea, sugar- * The fact of reeds being occasionally used shows that this is not the comb jf the castellated white-ant, carried or washed to the surface of the ground. Tea Pests and Blights. 343 Various Forms of White-ants. cane, dall, gram, etc.) and, having made an entrance through the bark, it tunnels the roots and stems, unobserved for the most part, until by storms these are blown over and the existence of the pest revealed. ( Reg. No. 128. ) 666. Mr. E. E. Green in his interesting little book The Insect Pests of the Tea Plant, makes the remark : " I have recently received from different planting districts, several specimens of full-grown tea-stems completely hollowed out by a kind of white-ant. It is quite a dis- tinct species from the common white-ant that attacks dead wood arid sawn timber, being fully twice as large as the latter, and feeding upon green, instead of dead, wood. Of the species at present under notice, I have seen only the worker and soldier ants which were taken from the galleries excavated in the tea-stems." It thus seems probable there may be many species of white-ant that would fall under the section of those that directly attack living plants, and are thus pests to agriculture. They may be said to agree on the main point of commencing their depredations, for the most part, on the roots or low down on the stem, or, at times higher up, by entering the stem through any openings in the bark that may be afforded them. 667. Conditions of an Ant Community. Each nest of white- ants is supposed to consist of a Queen-ant an unwieldy creature that lays all the eggs of the community ; Ant-neuters the workers and soldiers ; and wingless Larvae both male and female. The last- mentioned become winged at a certain season of the year, and escap- ing from the nest in countless numbers and late in the afternoon, migrate from the ancestral dwelling. After a time these lose their wings and crawl away, in pairs (one male and one female), when cer- tain of the females in time become queen-ants and give origin to new colonies. After impregnation, the abdomen increases vastly in size. An ordinary sized queen may be put at from 2 to 4 inches in length and fully half an inch in thickness. Mr. Green says that the queen may attain a length of 6 inches, and that she lives for several years. Mr. J. Scott (quoting from Dallas) remarks that 80,000 eggs are sometimes laid by the queen in the course of twenty-four hours. Mr. Cleghorn remarks, that there are often two or sometimes even three queens, as also a masked (reserve) queen to each white-ant -hive. The latter remains inactive within the royal cell until the .VHITE-ANTS. Ceylon Species Livinsf on Tea Bushes. Conf. with page 368. Queen White-ants. Neuters. Male and Females. Number of Eggs Laid. 344 Report of Investigations in Assam Pseudoneuroptera (Termitidse). TERME TAPROBAI Reserve queens. Distribution. Mud-covered Ways. Subterranean Action. queen dies, out of season or from some unforeseen circumstance. The reserve queen seems to be derived from the annual swarm of winged insects, one being purposely carried to the royal cell for that purpose. It is not enough, therefore, to remove the queen, if the masked or reserve queen be left behind, she will immediately take the place of the queen, and continue the production of eggs. But if all the queens are destroyed the ant-hill is abandoned. 668. Distribution. There is hardly a situation from Cape Como- rin to Kabul or from the tropical swamps of the plains to the temperate slopes of the Himalaya, where some species of termite is not met with. They may not be very abundant, but they are there. Afford them favourable conditions of food and leave them unmolested for a short time, an inconceivably short time, and they will multiply to a perfectly appalling extent and effect destruction in the least sus- pected positions. Most persons who have been stationed in dis- tricts badly affected by white-ants have witnessed beams, rafters, tables and other articles of house-hold furniture suddenly collapse, owing to the interiors of certain portions having been eaten away to a shell, only just sufficient to carry the varnish or paint and to leave the article the external semblance of unimpaired strength. All unsuspected, these minute workers have carried destruction forward, devouring the drier and more central wood first, working, in other words, from the centre towards the circumference as they ascend from the damper to the drier extremity. 669. Mild Encasements Residents in the East are also fami- liar with the way white-ants encase with mud the stems and branches of trees, forming for themselves thereby covered ways that extend from the level of the ground often to the topmost bough. On these encrustations being removed the bark is seen to be pale-coloured, because of the superficial and drier layer having been eaten away. The white-ants do not, at first sight, appear to do any more serious injury to the barks of the trees, though it would be hard to believe that they are not injured by these coatings of mud. But if the white-ants don't eat the bark, the very natural question arises, for what purpose do they form these mud-protected passages ? ( Con/, with next page.) It is a very generally accepted opinion that white-ants will not eat living and growing wood, and consequently that they do not kill, though perhaps they injure, living plants to some extent. This Tea Pests and Blights. 345 White-ants. opinion, I feel satisfied, may be true of certain forms of white-ants, but is wholly untrue of others. 670. Influence on the SoU and Boots. There surely can be no doubt that white-ants, if permitted to take up their abode for some time in and among the roots of a plant, do incalculable harm. During their subterranean operations they remove the earth from below to form the mud encasements above ground and around the stem. Speaking of the tea bush, it is by no means an unusual state of affairs to find the plant growing as it were on the summit of a dome of hardened earth that surrounds the cavernous dwellings of its colony of termites. A section made by means of digging a trench, for 3 or 4 feet deep, across the space occupied by the bush and hard against the main stem, will reveal a most un- healthy state of affairs. At a depth varying from i to 3 feet a large central cavern will be found and fringing this numerous smaller ones. In fact an elaborate system of excavations will be revealed, and found to be occupied, like the Roman catacombs of old, by both the living and the dead. The roots that stretch across the larger caverns will be seen to have formed bark and to have assumed, to all intents and purposes, the condition of branches. The delicate absorbing fibrils will, moreover, be observed to have all disappeared, so that it needs little explanation to enforce the opinion that there has been a useless accumulation of plant energy below ground at the expense of leaf production above. But this is not all. A serious disturbance to the' drainage of the soil and to its powers of retaining .moisture has been effected by these unbidden colonists. When white-ants infest a neighbourhood, to any great extent, the soil is hardened, caked and dried to a degree that in hot weather is sure to prove disastrous to the crop and may ultimately even endanger the life of the older plants. On the other hand, during the rains, a surface wash takes place and an uneven percolation that may be noted to cause the subsidence of certain bushes. This necessarily means that the roots are torn from their positions and killed, food being thus provided for the white-ants and an entrance afforded them to the older woody portions. The presence of white- ant encasements on tea bushes should at once be regarded by the planter as giving warning of the necessity for immediate attention to that part of his estate. WHITE-ANTS. Influence on the Boots. Effect on Drainage. Influence on the Soil. 346 Report of Investigations in Assam Pseudoneuroptera (Termitidae) . TERMES TAPROBANES They Attack Living Plants. Mode of Attack. Object of Hud Deposits Diminish Water- supply. 671. They Devour Living as well as Dead Wood. It is freely admitted that white-ants will attack the timber of very nearly every species of tree. Occasionally one hears of the great merit of this wood and that (particularly teak wood) as being proof against white- ants. A nd in some few instances this is doubtless true, though it would perhaps be safer to say, that the merit is but relative. In some cases life has hardly left the plant when it becomes attacked by these destructive creatures. In others, the timber has to be fairly well seasoned, and in still another sort has to be so old that its pro- tective resin or other substance that the white-ants have an aversion to, has been dissipated. But be such immunity only comparative or complete, the main principle remains the same that white-ants will attack and devour practically any dead wood wherever it is left exposed to them and undisturbed for a short period. 672. But there are many directions in which these generalizations regarding white-ants and their depredations may be entirely upset. It is not uncommon to find the opinion advanced that white-ants can and do attack living plants. With that opinion I entirely concur. Let the mud encrustations of the bark be carefully removed and the ant road-ways followed upwards, until the stump is reached of a withered branch or the scar from which a branch has been wrenched, and the observer will witness how white-ants ultimately devour as they gradually kill plants. They will be seen to have eaten, or nearly so, the whole of the severed portions, but having found a passage through the external zone of living and growing structures, have begun to attack the fully-formed wood. They have deposited a dense coating of mud within the gaping wound and splintered timber with a two- fold object of preventing the process of healing and of supplying an absorbent plaster that will suck the moisture from the wound and transmit it to the air. In a very short time a layer of the wood will be thus killed and rapidly devoured. Layer upon layer follows until the stem is cut into very seriously, if not entirely severed. The circulation of the sap having been thus intercepted these mining engineers turn upwards into the dead and dying wood. Operating below ground and thereby diminishing the supply of moisture, while availing themselves at the same time of every abrasion or injury to the stem or its branches above ground, is it to be wondered at that the process of destruction, though it may be almost imperceptible, is Tea Pests and Blights. 347 White-pnts. nevertheless certain in its ultimate result ! But let it be clearly observed, most white-ants live mainly on wood, not on green vegetable matter. The majority will not, as a rule, kill the green sapling, nor attempt to eat their way through the external zone of green wood of healthy plants. They will preferentially attack plants that contain a central axis of fairly well-formed wood, and may require even then the aid of some'accidental agent to give them access to the wood. By their action below ground they dry the roots, the bark of which is much thinner and not permeated to the same extent by sap as the bark of the stem and its branches. The species that attack seedlings or small woody shrubs generally commence operations from below. Those that live on trees, on the other hand, start their depredations, as a rule, above. The result is the same in both cases, the wood is first dried and killed, then devoured. 673. Practical Considerations. The story of the manner in which white-ants can and do attack and kill plants and thereafter eat the woody portions of their stems and branches, is true in thousand and one modifications. Let a boring insect make an entrance into the stem, branch or root, and white-ants will soon follow. Let the planter prune ruthlessly, leaving large surfaces or snags, or torn portions of wood exposed to the action of the air and if white-ants are about they will rapidly cover up his slovenly work with a shroud of mud. The vigorous efforts of the living bark may, however, more or less completely embrace and enclose the scar, but sooner or later the plant will give clear indications of its kanker- ous state by ceasing to be productive. The bark may appear quite entire and comparatively healthy. On being probed, however, ii will suddenly snap asunder and reveal a mass of mud within a shel of living tissue. 674. These are no imaginary pictures. I have already alluded t< this subject under Pruning. Hardly a tea garden exists in whicl the evil effects of pruning followed, it may be, by the depreda tions of white-ants cannot be seen. Bushes will be found here an there all over most estates, in which the lower half of the stem is portion of an old shell, perhaps not more than half an inch in thick ness and 2 inches in breadth which carries on its apex, a sickly an distorted dome of useless and unproductive branches. In othe words, it is no uncommon occurrence to find the lower half of th HITE-ANTS. a ofSt< It is First Dried, and Ulled, Then Devoured. Boring Influence of Pruning. Hollow Stems. Tea Bashes on Stilts. Con/, with para. 22O. 348 Report of Investigations in Assam Pseudoneuroptera (Termitidae). TERMES TAPROBANES Rotten Stems Wholesale Destruction. Young Tea Attacked. Stems Cut Across. How this is Accomplished stem gnarled and rotten with numerous mud stumps representing abortive branches or having one side only alive, the place of the other being taken by a great open scar, perhaps mud encased and infested with white-ants. 675. This is what might be described as the normal condition of a large percentage of the bushes in many old gardens. But one not infrequently hears of wholesale destruction where both young and old tea have suffered, more especially the former. During my tour in Assam I was shown over not a few gardens where a high percentage of young tea had the stems encased with white-ant mud and where very many plants were being directly attacked by the insects. Through the kindness of Mr. W. H. C. Whigham, I have on my table samples of tea three to tour years old, well formed and healthy looking, and which had, I am told, attained a height of 6 to 8 feet.. In many of these samples the stems have been cut almost square across, at a height of about 3 to 6 inches above ground. In other cases the stems have been furrowed and excavated to such an extent as of necessity to kill the plants. And this has beyond doubt been accomplished by white-ants upon otherwise healthy plants. Mr. Whigham has described very clearly the manner in which in many cases the white-ants had effected an entrance into the well- formed central wood of his samples, and his views corroborate my own observations. He says : "The lowest branch of the tree, some 2 or 3 inches above the ground and frequently springing from the surface of the soil, is injured in some way at the point it leaves the main stem, by some borer or other pest. It then drops, withers and finally falls off from the tree. White-ants (or what we commonly accept as being white-ants) have by this time effected an entrance into the tea bush. Working upwards, eating out the centre, and leaving the stem hollow. The first storm of wind breaks off the tree just above the ground." Further on Mr. Whigham adds : " I am unable to state what causes the low lateral branches first to droop and then fall off from the tree. I can discover no borer or other insect, but it is possible some such pest may, in the first instance, show the way for the white-ants to follow. The damage is most apparent from August to December, when, usually speaking, white-ants are most abundant and visible. It being too dry at present (February) for these pests to continue their ravages Tea Pests and Blights. 349 White-ants. amongst the tea bushes. I have never seen any clearance so devas- tated as this one has been from what, after a long experience of Assam and Cachar, I should name to be white-ants." Speaking on the subject of the season of the year when ants are worst, Colonel Money {Cultivation and Manufacture of Tea, p, 90) says : " From the close of the rains to the cold weather is the worst time for white-ants, and the time the planter should guard particularly against their ravages. At that time if he examines his trees closely, he will very likely find white-ants on a quarter of the whole." 676. Opinions of Authors and Practical Planters. A writer in the Tea Cyclopaedia says : "I had a belief that white-ants only attack old gardens which are not kept clean, and where dead wood is allowed to rot ; but it is not so. I see that the white-ants will infest young and old gardens equally, though every care be taken to keep them free from decayed timber. Our garden is only 2\ years old, and the best block is suffering from the depre- dations of the white-ants. It is heart-rending to see a young thriving bush, which showed no symptoms of decay in the evening, lying prostrate on the ground next morning, with a hole in the trunk an inch long and \ inch in diameter. I consulted several of my brother planters, old and experienced, in Chittagong, and they all advised me to keep up constant hoeing, but it had no effect. I next tried kerosine oil, and painted every bush in the block with a brush, but it was of no avail." 677. Messrs. Octavius Steel & Co. placed before the Agri.- Horticultuial Society a letter from one of their managers complain- ing of the ravages of while-ants. 678. Mr. Driver, of Loharduggah, complained of the depredations of white-ants on tea. In Chota Nagpur they are found to attack the roots of many agricultural crops. 679. During my Assam explorations I satisfied myself that, although the common white-ant usually attacks the upper parts of the stem, in the manner already detailed, another form a smaller insect attacks the roots of recently transplanted seedlings and the plants in nursery. The external mud encasement around the lower portion of the stem (seen in the latter case) is intended very possibly to suck the sap from the bark and dry the wood, thus preparing the way for an advance from the roots to the stem. That a system of sucking WHITE-ANTS. Season When Most Severe. Opinions of Authors. Kerosine oil useless. Mud Encase- ments on Seedlings. 350 Report of Investigations in Assam PseudoneurOptera (Termitidae). TERMES TAPEOBANES Objects of. From Whence is the Moisture Obtained ? White-ants in Sylhet. Con/, with paras. 665 (1), 696. Influence of moisture, both from the plant and the soil, is a governing principle, so to speak in their methods of destruction, must be evident to every person who has given this subject any degree of consideration. Mr- Whigham put this matter pointedly to me the other day, during a march through some portions of the Hautley Estate. He took me to a castellated hillock, and informed me that every second or third day he had ordered the top to be knocked off. Time after time it had been replaced. The soil for months past, Mr. Whigham explained, had been parched, not a drop of moisture to be had anywhere for the poor tea bushes, and yet these little pests seem to find the moisture necessary for their building operations. The explanation no doubt is, that they gradually suck the moisture from the roots, from the soil, and even from the moist bark, below their mud encasements, and also utilise the dew found on the leaves. Wherever obtained, water is employed in the repairs or construction of the castellated hillocks or mud encasements, and exposed to the air is soon dissipated with the not unnatural result that the soil is gradually parched to an injurious extent, and in time the plants are killed. 680. In a letter, which I have had the pleasure to receive through the Indian Tea Association, Mr. James Hall, of the South Sylhet Tea Company, writes, " I am certain that the mound-forming ant does little or no harm to tea. There are in this valley gardens covered with ant-hills, and these gardens, as a rule, have not suffered from the ravages of the white-ants. There are other gardens where there are almost no ant-hills, and on these gardens the bushes were, for the first year or two, cut down by thousands. The amount of damage done by white-ants depends entirely on the nature of the soil. On light soils, more especially if telah or plateau, they are usually most destructive. The ant-hills on these soils seem to me to be different from those made by the jungly or larger white-ant. They are usually not so high. If Dr. Watt cares to visit Sylhet, he will see gardens almost without ant-hills, that have lost 10 per cent, plants from the ravages of white-ants, and others, where ant-hills are very plentiful, that have hardly lost a plant." 681. In another letter forwarded to me, Mr. E. Scarth, Superin- tendent of Attaree Khat Tea Company, says, " The ant which, so far as my experience goes, is to be feared as doing damage to tea plants, is the small species that lives under ground in oblong caverns : the large Tea Pests and Blights. White-ants. white-ant that raises large hillocks does comparatively little damage, and if the queen ant is dug out from the hillocks, the rest of the ants leave it. I have levelled many of these deserted hillocks and planted them out with fair success." " It is the small white-ant which is our enemy, and a good trench hoeing or forking in autumn should, I con- sider, be the best remedy. 682. Recently I have had the pleasure to receive, through Messrs. Balmer, Lawrie & Co., a most excellent series of examples of white- ant-destroyed tea bushes. The ants supplied along with these speci- mens as having been picked out of the mud deposits within the stems, proved to be the fourth species in the above enumeration. Mr. F. E. Winsland, in his letter that accompanied these specimens, made some useful observations. He proposed to collar prune the affected plot, to paint the exposed sections of the stems with Stockholm tar, and, in order to catch the white-ants, he intended to fix in the ground around the stump of each bush three stems of tamal grass. On these becom- ing full of ants he proposed to collect and have them destroyed. I may remark that the method of using food traps for pests is often a dangerous one, since instead of catching what exists the supply of food furnished may cause an increase in the numbers of the pest. The treatment proposed by Mr. Winsland is, however, the only satis- factory one with old gardens badly affected by white-ants, namely, to collar prune. Their food is thereby completely removed, and the exposure of the soil to the sun, as a rule, kills or drives away the ants. Since my answer to Mr. Winsland's letter gives certain particulars that may be of value, it will be found below, published as an appen- dix to this chapter. 683. Mr. G. E. Noad, Manager, Cherrie Valley Tea Company, Kumbhir, Cachar, in a letter to the Indian Tea Association, says that, " White-ants do a terrible lot of damage to any bushes that have to be cut down." A writer in The Indian Agriculturist says, " Some lands are infested by these pests ; other land, again, is quite free from them." 684. Having furnished in the above paragraphs information re- cently to hand, corroborative in certain directions of the remarks originally offered by me, in the first edition of this chapter, it may be as well if I give here certain opinions that are opposed to my views : 685. The late Mr. J. Scott, formerly Curator of the Calcutta Botanic Gardens, in a most instructive and thoughtful paper entitled WHITE ANTS. Hillocks Planted Out. Correspon- dence, see Appendix, PP. 366-369 Food Traps. IHJured a CoTlar Prune. White -ants In Cachar. Living Plants 352 Report of Investigations in Assam Pseudoneuroptera (Termitidse). TERMES TAPROBANES Suck the Juice. Dead and Dry Parts Eaten Fresh Living furfaees xposed. They Remove Earth from Base of Cuttings. Do Much Mischief. " Notes on Horticulture in Bengal, " says of white-ants " There is a prevalent, but certainly a mistaken, notion, that they also devour the living parts of plants. Cuttings of Sugar-cane, as also those of many of our garden plants, are said to be especially liable to their attacks, and I have thus been induced to bestow considerable attention on their habits. In sugar-cane cuttings, I find that diseased portions are very quickly attacked by the white-ants, and scooped clearly out to the very surface of the living part : further gnawing then ceases, though the insects remain to sip the exuding juices and this, as fre- quently happens when the diseased surface is large so weakens the cutting that it is unable to afford the necessary nourishment for the young offshoots, until they are self-sustaining, and thus all die, and of course become the prey of the white-ants. It is doubtless from examination of the cuttings of these stages only that they have been falsely accredited with their complete destruction. Though I am thus certainly of opinion that the white-ants do not eat the living parts of the cane-cuttings, I nevertheless believe that they cause a certain amount of damage to them. This they effect by gnawing off the dead and dry parts, thereby exposing a fresh and living surface, from which they continue to draw the thin freely exuding sap, and thus weaken and intensify the disease in a manner which might have occurred naturally. I thus think that of two similarly and partially diseased canes, of which one is free from, the other attacked by, white-ants, the latter will be less liable to resist the further inroads of the disease than the former. For the same reasons they are likely to cause injury to cuttings of our ordinary flowering plants; but this can only occur through neglect of the mali. To attract the white- ants, there must needs be a partially dead cutting in the pot on which they, in the first instance, ensconce themselves; thence extending their excavations they come in contact with, and perhaps remove the soil from the cicatrising base of other cuttings, thereby checking may- hap killing them, in thus withdrawing their supply of moisture. In these respects, then, I admit that white-ants may, and I believe do, cause mischief to cultivators ; but that they really devour the living parts of plants is, I believe, wholly unfounded." 686. If the opening sentence and the concluding expression of per- sonal opinion were removed from the above passage, I should have no objection to its appearing as an opinion supporting powerfully my con- Tea Pests and Blights. 353 White-ants. tention that white-ants kill tissues and, in time, whole plants, and, when so killed, devour them. It seems to me to beg the question to say tha they do not eat living and growing tissues. If they possess the powe: of slowly killing plants the practical result is the same to the tea culti vator as if they ate them alive. 687. So, in the same way, much has been said on the theme tha white-ants are only secondary agents, following on the path of a grub that eats the roots, or of a borer that works in the stem. That con tention (which I admit is doubtless true in some instances) is, I venture to think, inadmissible as a general guiding principle in the practica consideration of white-ants as a pest to crops. Dysentery may be a disease that very frequently follows some other ailment, but it is an aspect of the patient's case that must be dealt with promptly. T argue that white-ants may have been unjustly accused of being a primary pest, is dangerous. Mr. C leghorn concludes an interesting paper on white-ants (in which the contention prevails that they only secondary agencies in the destruction of crops) by the following passage which discusses the condition of affairs found in three diseasec Araucaria trees in the Agri.-Horticultural Society's Garden : " At the base of each Araucaria, from ten to thirty grubs were found They had bored into, and through, the stem, leaving a lot of dead wood on each side of the borings, and demolishing the pith ; White- ants had thus gained an entrance to the pith which they had destroyed, in one case to a height of 18 feet, and in the others to 1 3 feet and 1 7 feet respectively ." It was unfortunate that Mr. Cleghorn did not think of telling us what proportion of these destructions had been primarily accomplished by the grubs, and how much should be laid to the charge of the secondary agents of destruction. 688. Mr- J. B., of . . . in a private letter dated May 25th, 1896, (which I take the liberty to publish since it contains much of public interest, though I suppress the names -of the persons concerned), in this connection, while commenting on the advanced proof of this chapter, (sent to him for opinion), says : " Mr. J. H., General Superintendent of the ... Company, and Mr. J. L, Superinten- dent of . . . . , agree with me that white-ants will not attack a healthy tea bush"; if they did, I am afraid there would not be a tea bush left in Assam. I have seen healthy tea bushes thriving in the middle of an ant's nest." 23 WHITE-ANTS. Kill First Then Eat. Affirmed to be Secondary. Agents. Unjustly Accused of being Primary Agents. The Stem Eaten for 1 8 feet. Con/, with page 368. Will not Attack Healthy Bushes. 354 Report of Investigations in Assam Pseud oneuroptera (Termitidae). TERMES TAPROBANES. All Old Bushes are conse- quently Un healthy. Collar-prun- ing Favours White-ants. A Percentage only Unhealthy. Chances Given to White-ants. Several Forms of White-ants. One can Attack Seed lings, the Other Decayed Wood. " You have a very strong case, I own, at Hautley garden, but the general opinion is that there must be some other cause, the bushes being sickly. White-ants then come in for the final destruction. I do not suppose a single old tea bush is pruned down, or what we now call collar pruned, without being found to be attacked by white- ants in the centre of the old and decayed stump. You pointed this out yourself to me, and my experience is that in all cases of collar pruning the centre of the original stump gradually decays, and is eaten away by white-ants; while from the outside of the stump (very often under ground) new shoots start, the nucleus of fine and healthy bushes. In collar pruned tea, one is fortunate if one does not lose more than from 5 to 10 per cent, of the bushes, but we are well rid of these, for they are usually the sickly ones that cannot stand a pruning of such a drastic nature, and the only remedy is to fill the vacancies up with young plants." " I mention this simply to show what a chance we give to white- ants to destroy our tea wholesale, but they cannot do it." Mr. B. then concludes his letter by the following sentences : " I would ask a simple question and it is this : Has any planter, by the application of any of the emulsions you name, brought a sickly bush round (i.e., a bush to all appearance being destroyed by ants) ; the ants may be destroyed, but has that bush ultimately recovered and become vigorous ? " 689. I would venture to point out that the above criticism has over- looked, as it seems to me, a point I have laid stress upon, namely, that there are several forms or species of white-ant, one that will dis- tinctly attack young seedlings, and another that has not the power to do so, but commences its operations on dead wood. I might mention a score of gardens in Assam where I found the former white-ant attack- ing seedlings direct, and my correspondent may certainly congratulate himself that it has not so far been his misfortune to make their acquaintance. The other form may, however, ascend the stem of old plants, and, if it finds wood anywhere exposed, will devour that, and, having thus found its way into the stem, will eat down the centre until in time it produces the condition Mr. B. has so vigorously described. The answer to the question put above has certainly to be given in the negative, for, if badly attacked, I believe there is no cure but collar pruning. It may be that white-ants find sickly plants more Tea Pests and Blights. 355 White-ants. easily preyed upon than healthy ones. The diseases they were suffering from, however, were possibly curable, whereas, once the centre of the stem has been eaten out, there is no cure. It is not cure, therefore, that I have tried to advocate but improvements in cultiva- tion as methods of prevention and also the eradication of the pest if that be possible. But I should like to ask if the decomposition of the centre of the stem is a necessary and unavoidable consequence of age and whether only old trees have their stems so decomposed ? If that be so, then white-ants are doubtless fulfilling a provision of nature in destroying what is useless. In my opinion, however, white- ants are very much more frequently a cause, than a consequence, of the decomposition of the stem. 690. White-ants Attacking Mango Seedlings. Speaking of the form of white-ant that attacks the roots of seedlings, though a di- gression somewhat from a report on the pests of the tea plant, I may illustrate my contention by a passage or two from a most instructive paper recently to hand from the Settlement Officer, Balaghat, in the Central Provinces : " White-ants," that Officer writes, " are espe- cially fond of young mango trees. In some villages repeated efforts to make a mango grove have failed, on account of the roots of the young trees being attacked by white-ants. I once doubted this fact* and was disposed to believe that in these villages the people were unusually negligent in watering the saplings." He then goes on to narrate how he tried to raise some mangoes near his own bungalow, but " a number of the saplings died, they being in most cases attacked by white-ants. I have dug up three of the trees in different stages of the white-ant disease. One of the plants was almost dead, and it would have been difficult to prove that the white-ants were not inno- cent scavengers removing useless dry wood. Another tree was half- dead, and the theory that exonerates the white-ant from the charge of devouring living timber, could only be maintained by crediting the termite with a marvellously accurate prophetic instinct, that told the scavenger which of the trees were already doomed to die, and might be removed as useless, for the tree was not yet dead, but only likely to die shortly. In the third case, the tree still looked quite green save for a suspicion of unhealthiness about some of its leaves. On dig- ging it up I found that its roots had been eaten through in places by white-ants, and that a detachment of the voracious termites was 23 A WHITE ANTS. Prevention rather than Cure. Cause more than Conse- quence of Stem Decom- position. Roots of Seedlings Attacked. Scavengers Removing what Is Prophetic Instinct. Green Wood Eaten. 356 Report of Investigations in Assam Pseudoneuroptera (Termitidse). TERMES TAPROBANES Field Crops Devoured. Saplings Cut Square Across also Fur- rowed. Ruthless Destruction of Branches. External Abrasion Necessary. actually pushing its way up the heart of the sapling eating its path through perfectly good juicy wood. " " I have found fields of tur (Cajanus indicus) in which a number of the plants have withered owing to the roots being eaten by white-ants, and in gram fields I have had similar damage pointed out to me." But having given the above review of information brought to. light, more or less, as the result of the publicity given to the first edition of this chapter, I may return to the original text. 691. Death of Twigs Low Down on the Stem. As already stated, there is no doubt Mr. W high am 's specimens have been cut across and furrowed by white-ants, and although, he says, he has been unable to solve the problem of how the lower lateral branches have been killed, he is very possibly correct in believing that it was through the death of such lateral branches that the white-ants found an entrance to the wood of the main stem provided they did not enter by the roots. Where the destruction has not been preceded by a borer or other parasite, nor has been caused by defective pruning, it may be due to the branches being broken, or simply by being imbedded dur- ing deep hoeing. But there are many circumstances that might each contribute to injure the lower branches. The point of importance, that it is here desired to urge, is that, without some external abrasion or injury, giving access to the central wood, white-ants are, as a rule, unable to accomplish their mission of destruction. The risk the lower branches are exposed to during heavy hoeing is, however, very great, and where while-ants are known to abound, it should be a point for careful study whether it would not be the wiser course to remove all the lower branches at an early stage and encourage the formation of only one or at most two or three main stems with no branchlets for some distance above ground. 692. Best Time for First Pruning. A question raised by Mr. Whigham has been partly disposed of by the remarks already made, but it may be emphasised here. He says : " The full-grown bushes appear to be selected in preference to the younger and smaller plants. Do you suppose, as the bushes grow older, they develop something peculiarly favourable in the wood or sap for the pests to feed on ? Would earlier pruning, say after the plants have been a year in position (cutting down to 6 or 9 inches) strengthen the plants ? " Tea Pests and Blights. 357 White-ants. 693. The answer to the former question must of course be that it is not a sap favourable or otherwise that white-ants desire, but the absence of sap. The central wood of a growing plant after a certain age, might almost be described as dead. It is not at any rate actively living and growing, but is timber more or less completely formed, and the older it becomes the more true is this observation. Fully deve- loped wood is the food that white-ants are partial to, and such has only to be exposed to them to be devoured. The best protection to the stem, far and away superior to all insecticides, is a healthy and entire bark with a vigorous sap-wood. 694. The answerto Mr. Whigham'8 second question might be in the affirmative, but the point is one that should be carefully determined by practical tests. There would seem to me no doubt that the process of pruning, when seedlings are three or four years old, exposes them, in certain districts at all events, to a far greater extent to the attacks of white-ants, than pruning accomplished at an earlier stage. But on general principles of tea cultivation, I have already recommended a fairly early period being fixed for the first heavy pruning, say, not later than one year. I have in fact so fully expressed my views on the subject of pruning, that it would be superfluous to repeat them here. I believe bad pruning to be the chief reason why the centre wood of old bushes is so very frequently rotten and white-ant infested. Far from being prepared to accept the state of afiairs that prevails, as a necessary condition of age, I am confident it is largely preventable. 695. But the first step in that direction is the recognition of white- ants, each and every form of them, as injurious to tea. I have already stated that I do- not believe the castellated form ever directly attacks and kills bushes, but I am abundantly satisfied that, even it is capa- ble of the greatest possible mischief. It will at once attack any dead wood that may be on a tea bush. Once any species of white- ant deposits its mud encasement on dead wood, it eats slowly, and, as it progresses, the mud sucks out the moisture and dissemi- nates that to the air, so that, deprived of its sap, layer upon layer, is killed and eaten. White-ants thus work into the very heart-wood and run up or down the stems and even along the roots, with a natural enough result. The bush becomes unproductive, and is pronounced old and diseased. White-ants are an ever-present danger that have aged prematurely many gardens, and are to a WHITE-ANTS. Seasoned Wood Preferred. Heart Wood s Practically Dead. Early. Action of White-ants Preventable. Mud Encase- ments Suck out the Sap. Gardens 'rematurely Aged by White-ants. 358 Report of Investigations in Assam Pseudoneuroptera (Termitidae). TERMES TAPROBANES Hillock Forming Ants. Conf. u-ith 1st form, Paras. 665, perfectly alarming extent lowering the productive capabilities, I fear I am correct in saying, of most gardens in Assam. All the while they are but too frequently looked upon as necessary evils, harmless little creatures that have by some misguided people been falsely accused of eating living plants, while they only kill them first and eat them afterwards. 696. Harbouring White-ants. Having thus briefly dealt with the manner in which white-ants attack living plants and the destruc- tion they are capable of effecting, I turn now to the circumstances that may be regarded as harbouring these undoubtedly dangerous pests. The very foremost consideration should be given to the removal, as far as possible, of all ant-hills or nests. Many planters prefer, so they told me, to leave these alone, because of the all but universally admitted opinion that tea will not grow on the top of ant-hills, and that the area of sterility is greatly extended by levelling them down and scattering the earth over the surrounding land. While in Assam, I examined many large rounded mounds (some of them with tea growing on the top) which in every case I was told were " old ant- hills, " but I did not come across one in which I found ants, nor one of this class described as a new ant-hill. While not questioning the accuracy of the opinion given me regarding these mounds, nor even that it might be possible to find many that contained countless myriads of ants, I simply affirm that I did not come across one within the limits of a tea garden that was inhabited, or seemed in- habited, by ants. I found many similar round ant-hillocks in the forests and jungles, all inhabited by the ant. So, again, the castellated ant-hillock is by no means common in tea gardens, though occasionally one may be seen on the roadsides or commencing to grow up around a bush. The contradictory opinions that one obtains as to the sterility or fertility of ant-hillocks may, as it seems to me, proceed from the two kinds of mounds, above indi- cated, being widely different. At all events my observations led me distinctly to the conclusion that the white-ants of the jungles love neither the jungle clearances, accomplished by the planter, nor the object of his solicitude. 697. This is, however, a point regarding which there should be no uncertainty. Very little study would suffice to remove all doubts. Clearly if the rounded mound-forming ant be a distinct species, and Tea Pests and Blights. 359 White-ants. one that is comparatively not injurious to the tea, but dies out after it has been exposed for a few years to the full action of light, there would be little or nothing gained by levelling the mounds. Better leave them alone for a few years until, by the growth of weeds, they had been shown to be converted into fertile soil. But if I am wrong in this suggestion and they are, as some planters believe, great father- lands of this tea pest, the sooner they are levelled, dug out and the queen ants destroyed the better. Whatever present expense this may entail, that would be preferable to increasing the danger hereafter of white-ants. 698. But with the subterranean white-ant, I shall go further. Wher- ever that insect may be seen on the surface soil or lining the tea bushes or other objects with mud, to an abnormal extent, I should have them traced out, if possible their cavern discovered, and the comb-like structure and the queen ant destroyed. I am fully aware that in many estates this might mean digging holes 2 or 3 feet in depth every few yards. But supposing it did, a process of attempted eradication, however incomplete, would be distinctly more profitable than the losses at present sustained. The simple fact of disturbing the white- ants would be beneficial, and an occasional deep hoeing, such as I have mentioned, at isolated points over an estate, would have other advantages. By leaving white-ants undisturbed, the planter is directly harbouring one of his most formidable enemies. 699. Burying Wood, primings, etc. During the clearance of new land nothing could be more pernicious than the habit of burying stumps of trees, branches, roots, etc., in the soil. Food is thereby pro- videfi all over the future estate for great colonies of white-ants which, when their store of food, thus provided by the planter, gets exhausted, will lose no opportunity to attack the tea. This argument holds good with even greater force to the still more pernicious habit of bury- ing the prunings from the tea plant itself. This subject will be found fully dealt with in another chapter, and it is only here alluded to as having a direct bearing on the question of white-ants. 700. All woody structures, whether from the jungle clearances or the subsequent tea prunings, should be burned. In that form they are valuable, while as wood they are dangerous. Mr. Whigham has asked the question whether the stakes employed in planting out tea tend to introduce and distribute the pest of white-ants. My answer is WHITE-ANTS. Eradica- tion. Burying Prunings. Con/, with para. 17O. Burning Prunings, Report of Investigations in Assam Pseudoneuroptera (Termitidae). TERMES TAPROBANES Dry Wood Dangerous. REMEDIES. Digging Out. Tobacco. petroleum. Keroslne. that they most undoubtedly do so. I see no great reason for leaving stakes in the ground. It should be an easy enough matter to fill up vacancies since the lines formed by the living seedlings readily denote the places that require to be replanted. No dry wood of any kind should be left lying about in gardens that are addicted to white-ants, and the very first principle of prun- ing should be to remove all dead or dying, and therefore useless, wood from the bushes. Remedial Agencies against White-ants. 701. As already briefly indicated, the very foremost consideration should be given to the subject of eradication of white-ants. When and where possible they should be dugout, not merely by hand clean- ing the stems and branches of the mud encasements a sure indica- tion of the presence of this pest but by digging out and destroying the nest with its queen ant. Colonel Money says : " Digging round the plant where they are, disturbs their runs, and does much good. At the same time they should be brushed off any part of the tree they have attacked, and the tree should be well shaken. All this, however, only does temporary good, for they often are found as thick as ever on the plant a week later. " Tobacco water is beneficial, but in wet weather it is soon washed off. Kerosine oil is very efficient. A little is put round the stem ; but it is expensive. The next best thing I know is the earth-oil (petro- leum) from Burma, and this is cheap enough. It is thick, but used from a bottle it gets heated by the sun and is then quite liquid. " When white-ants are found on a tree, a little petroleum applied with a brush is put on the part they have attacked. They are also well shaken off, and a ring of oil is placed round the stem. My experience is that they will not attack that tree again for a long time. I was at first fearful that both it and the kerosine (the one, I believe, is only a manufacture of the other) would injure the trees, but both are safe." 702. On this subject Mr. Whigham says: "Earth-oil and tar damage the bark of the trees and cannot be used." Mr. Whigham, in a more recent communication, furnishes the following additional in- formation : "In the middle of the rains, 1895, I painted about 50 Bazaloni tea bushes on the stem, a little below and above the ground, Tea Pests and Blights. White-ants. with earth- oil, and the same number with tar. The result was identical in each case." " During the remainder of the rainy season the ants were kept away, but as the cold weather came on, the bark in nearly all instances was found to be eaten through by the tar and oil. The stem of the bushes were charred and burned looking as if a tight bandage of, say, 6 inches wide, had strangled the growth of the tree. Soon after this they lost their vitality, and had to be collar pruned down to the ground." 703. I have heard other planters also speak unfavorably of the use ofkerosine. Mr. Bam ber recommends a dressing with petroleum and earth-oil. He adds " It is most important that all ant-hills should be destroyed especially when near a nursery or young plantation, as if the plants are attacked at an early stage, and the main stem at all damaged, they will never recover, and yield the same as an uninjured plant. " It might be possible to destroy the ants before they take flight by burning sulphur or other material in such a manner, that the gases and smoke would penetrate the numerous passages of the hill, and either cause the ants to emerge or smother them inside, such a remedy could be easily tried, and would be far less labourious and expen- sive than cutting away the mounds, some of which are of great size. " Fires of brush wood could be lighted on the windward side, and either sprinkled with sulphur or covered with damp jungle or straw and old bamboo mats, to assist in forcing the smoke into the interior. " Small quantities of heavy earth-oil poured into holes bored in the mounds in a sloping direction would also, when burning with a limited supply of air, cause a heavy smoke to penetrate throughout." The above recommendations have been before the planters now for some few years, and it would be interesting to know if they have been tried, and if so, what degree of success has been attained. Personally I should prefer to remove ant-hills, at all cost, as being the more direct way of dealing with the pest, and the sooner this is accomplished the better. 704. Mr. J. Lindsay Alexander informs me that he found the cold infusion of the leaves of Adhatoda Vasica an effectual cure for pa white-ants. In another part of this report I have alluded to the proper- ties of that insecticide, and need not enlarge on the subject here. Mr. Alexander tells me that he found the contents of a kerosine oil- W KITE- ANTS: REMEDY. Kills the Bark. Sulphur. Fires. Smoke. Adhatoda. Con/, with iras, 12O-2, 292, 573, 589, 742, 758, 795. 362 Report of Investigations in Assam Pseudoneuroptera (Termitidae). TERMES TAPROBANE REMEDY. Queen Ant Killed. Neem Leaves Preventive Paint. can of the infusion, poured into the holes of a fairly well-established nest, sufficed. Shortly after being treated in this manner he had the nest dug out and found the queen ant and all the others dead. This result seems, therefore, fairly hopeful. It might be tried on a more extended scale and the results reported. I am not, however, very sanguine of the value of any insecticide in the eradication of this pest. Thorough and cleanly agriculture should in the long run prove both more economical and more effectual. White-ants should, in other words, be dug out, the roots of the bushes freed from their excavations and hives, and the stems and branches at the same have all mud encrustations removed. 705. In the Journal of the Agri. -Horticultural Society Mr. Liotard announced that he found a few leaves of the neem tree, buried in the ground, drove away white-ants from his rose bushes. The Assam lakhain no doubt might be used as a substitute, and from experiments performed some years ago I should be disposed to believe the insect may have an aversion to that substance. Many writers have affirmed that the fresh juice of the leaves of the American Aloe, poured on to a badly-affected plot of land, will drive away white-ants. 706. The Commissioners appointed in St. Helena, to enquire into the subject of white-ants, experimented with some sixteen different substances sent to them from all parts of the tropical world, as being useful preventions or cures against the depredations of white-ants. Some of these may be here alluded to : Mr. Robertson, of Ceylon, recom- mended sugar mixed with arsenic : another Ceylon correspondent mentioned arsenic, creosote, and bichloride of mercury. Mr. Davies, of Madras, recommended arsenic, aloes and chunam soap. Many writers spoke favourably of tobacco juice and common salt mixed, but the report may be said to have pronounced that each and every method had been tried, and none proved effectual either to check the ravages of the scourge or to protect woodwork from destruc- tion. 707. Useful Preventive. While travelling in Kattiawar some short time ago, my attention was directed to a habit that prevails in the Gondal State of painting the stems of trees to a height of 3 feet above ground with a red-looking substance. It was impossible to march through the State and not be struck with these red bands. I enquired the reason. In reply, I was asked to see whether any of Tea Pests and Blights. 363 White-ants. the trees so painted were attacked with white-ants. Throughout the States of Kattiawar white-ants are a positive calamity as they attack and practically destroy whole avenues of trees. I found the red paint, whatever it consisted of, was an effectual protection. In no instance did I discover trees encased with mud where the red ring was fairly visible. I enquired into the nature of the preparation used, and the particulars I obtained were published shortly after in a paper on the subject of Al dye (Morinda citrifolia, Agricultural Ledger No. 9 of 1895, pages 3-6), because Al was said to be the colour-imparting ingredient. The following passages may be here republished from that paper : Paint used against White-ants. 708. " During a brief visit to the Native State of Gondal, the writer recently gave this subject considerable attention. There seemed to be no doubt that His Highness the Takore Sahib, by his enlightened action in this matter, had effected a radical improvement. The trees throughout his State were all painted as described above, and not a single tree could be found that showed the mud encasements so characteristic of the presence of white-ants. And very possibly, as a consequence of the care bestowed on these trees, they were healthy and vigorous, while those in neighbouring States were sickly and badly attacked with white-ants. In consequence of these observa- tions the writer asked for information as to the composition of the paint which had been used. He was informed that the red colour was merely to indicate the fact that the trees had been painted, and that it was for the most part red ochre, but might also be made of the refuse of the Al Dye works. The useful ingredients were said to be as follows : 1 part dekamali gum (the resin of Gardenia gummifera or G. ludica). 2 parts asafbetida or hingra. 2 parts bazar aloes or musubar. 2 parts castor-oil cake. These are well pounded, mixed and kept in water for about a fortnight. When thoroughly united, and what may be called decom- posed, into a thickened compound, water is added in order to bring to the consistency of paint, and the colouring matter then added. WHITE-ANTS : REMEDY. Trees Painted Red for Three feet of Stem. 3*54 Report of Investigations in Assam Pseudoneuroptera (Termitidse). The mixture is now ready for use, and, if thoroughly applied for about 2 feet, will check the attacks of white-ants, and many other insect pests. Its effect will last for two years or more. The cost of the preparation comes to about 4 to 5 rupees per 100 trees. " But according to the information furnished from Gondal, dl (Morinda dye) refuse possesses no especial properties. From other parts of India the reputation is very general that it is of great value. Be that as it may, the red ochre added to the above prepara- tion, may not only be useful as indicating the trees that have been painted, but give a needful consistency, if it does not serve to me- chanically hold the other ingredients. It would, however, seem desirable to have the reputation of dl as a preventive against the attacks of insects thoroughly investigated, even supposing it be ad- mitted that experience in Gondal has proved that it is of no very special merit as a paint on trees. " The system of painting trees (as detailed above) might with great advantage be extended throughout India, especially in orchards ; and it is even probable that the Tea and Coffee planters might find the system of great value in checking the depredations of white-ants and other insect pests." 709. Since the above was written, the subject of the red paint to be employed against white-ants has attracted very considerable attention. So far the results obtained have abundantly confirmed the previous statements. I can confidently recommend the subject to the attention of planters troubled with white-ants or other pests that attack the bark of the tea bush. The paint is perfectly harmless. The ingredients are all readily procurable. They are cheap. The effects of one painting are said to last for two or three years. The thorough or imperfect manner in which it has been applied can be readily seen owing to the red colour. , 710. So far as I can discover, were tea bushes affected by white- ants to be thoroughly cleansed, to have the earth around them deeply hoed, even at the expense of cutting some of the roots, to have all ant nests removed when found, and to have the stems and branches, even some inches below ground and for 2 feet above, thoroughly coated with the Gondal preventive paint, we should very soon hear comparatively little of white-ants as a serious malady to tea cultivation. Tea Pests and Blights. 365 White-ants. APPENDIX TO THE CHAPTER ON WHITE-ANTS. Copy of a letter No. 1O9 Arb., dated 2Oth April 1896, from the Superintendent, Government Botanical Gardens. North-Western Provinces, to the Chairman, District Board, Saharanpur. In accordance with the orders contained in letter No. v~^- dated the 1 9th November 1895, from the Director of Land Records and Agriculture, North- Western Provinces and Oudh, to the Superin- tendent, Government Botanical Gardens, Saharanpur, copy herewith enclosed, I have the honour to submit, for incorporation with the District Arboricultural Report, the result of a trial made with a paint recommended by the Reporter on Economic Products to the Govern- ment of India, as a preventative against the attacks of white-ants upon growing trees. The paint was prepared according to the directions given by the Economic Reporter and applied to a number of mango, shisham, and sin's trees on the Sirsawa road that were badly attacked by white-ants. Before applying the paint, the coating of earthy matter deposited upon the trunks of the trees by the ants was removed, and in all instances, where the earthy deposit was entirely removed, the paint has, so far, had the effect of preventing further attacks by the ants upon the trees. In a few cases the men employed on the work of painting overlooked strips of earthy deposit lying in hollow channels on several of the trunks of trees operated upon. The strips of earthy deposit overlooked were painted over together with the cleaned portion of the trunk, but the ants took no notice of the paint when applied to the outside of their earthy runs, and therefore made use of the strips that were left as passages to communicate with the upper portion of the trunk where they continued their attacks as before the application of the paint. The experiment has, therefore, proved that the paint is an effective preventative against the attacks of white-ants if applied directly to the bark of attacked trees, but that it is of little use if applied without first entirely remov- ing all earthy ant deposit from the trunks of the trees. The trees experimented upon were 29 full-grown specimens averaging from 2\ to 3! feet in diameter. Ingredients for paint to the value of 813-13-0 were purchased, but, as the full quantity was not used, the actual cost of painting the 2 9 trees operated on was 7, or at the rate of 3 annas 10 pies per tree, nearly. I, therefore, consider the paint too expensive for extended use on large-sized trees, but its cost would not be prohibitive for use on young trees or saplings. In districts where it is found exceedingly difficult to estab- lish the commonest and hardiest of roadside trees owing to the pre- sence of white-ants, the paint would, I feel sure, prove most useful. Extract from Report by Mr. Lane, Curator of the Royal Botanic Garden, Calcutta, on a preparation used in Gon- dal State to check the destruction of trees by White-ants. " I prepared the mixture as directed in Dr. Watt's letter, and applied it to 2 feet of the base of two trees, as described WHITE-ANTS. Stems must be thoroughly cleaned before Painting. Effective Preventative. A Band of 6 inches in breadth might be as effectual as one of 3 feet. 366 Report of Investigations in Assam Pseudoneuroptera (Termitidae). Collections, of White-ants. in The Agricultural Ledger (No. 9 of 1895). The trees I selected were two that had ant heaps at the base and had been covered the previous season with mud encasements. Since the application of the preventive the trees have been free from White-ants. The trees still show marks of the preparation." From Assistant Secretary, Indian Tea Association, Royal Ex- change Building, Calcutta, 29th April 1897. No. 166-O. To (All Members of the Association). White-ants in Tea Gardens. DEAR SIRS, I am directed by the Committee to forward, for your information, printed copy of a letter, dated igth April 1897, from Messrs. Balmer, Lawrie & Co., together with copy of a letter from DP. Watt, C.I.E., on the above subject. From Messrs. Balmer , Lawrie & Co., 1O3, Clive Street, Cal- cutta, 19th April 1897. The Secretary, Indian Tea Asso- ciation, Calcutta. DEAR SIR, We have been taking a particular interest in the causes and effects of the While-ants and their depredations, and the writer, on a visit to Assam last November-December, went rather fully into the matter, which has brought about some interesting correspondence. The enclosed copy of a letter received from DP. Watt, dated 1 3th instant, being of considerable value in sug- gesting certain remedies to try and eradicate this pest. We have much pleasure in making the information over to the Association, and trust that the Committee will see their way to circulating a copy of the letter to all the Members of the Association. We should also be pleased if you will comply with his wishes, and send him a few copies when printed. . | A., Calcutta, the 13th April 1897. From George Watt, Esq., M.B., C.M., C.I.E., etc., Reporter on Economic Products to the Government of India. To Messrs. Balmer, Lawrie & Co., 103, Clive Street, Calcutta. GENTLEMEN, I have to acknowledge yours of the 2 9th March as also the box of specimens of tea bushes attacked by white-ants. I am afraid you will hardly regard the matter as one for congratula- tion, when I inform you, the samples supplied are the best for Museum purposes I have ever seen. I am sorry your correspon- dent was not as successful in the collection of the insect. To name the species, it is necessary to be supplied with a larger number, including the queen, in order to make sure that we have a complete series of all the forms that live within the colony, and collectively constitute the species. As you are aware, each species of white-ant has several forms queens, out-door workers, soldiers, domestic or household ants, etc. Now, we can only be sure of species (A) as Tea Pests and Blights. 367 White-ants. distinct from species (B), when we are able to examine and compare, side by side, the queens, out-door workers, soldiers, etc., etc., of each species. So far as 1 can see, the insect supplied is the small white-ant described by me in my note as not forming a castellated hive. I shall be obliged by your asking Mr. Winsland to select, say, two or three badly-affected tea plants, and examine each separately. I would wish him to get a small bottle, to be used for each tea bush. He should proceed by carefully breaking down the earth from the branches and stems, and having 100 or so of all the insects seen in these collected and put in the bottle. He will pick the insects up without injuring them by means of a twig dipped in the spirits of wine, and applied to the insects. He should then carefully remove the earth and cut a trench across the face of the ground in which the bush stands for a depth of, say, 3 feet. The trench should form a perpendicular face so as to reveal all the subterranean workings of the ant. The vertical face should then be advanced on to the bush, by cutting away a slice of 2 inches at a time. If combs are found, these should be carefully removed (or large pieces of them) and laid out on the ground to harden in the sun. Samples of the combs are necessary for a complete examina- tion of the species. As the section is advanced, a series of all the insects found should be picked up, more especially the queens, soldiers, and others that seem different in shape, size, or colour found above ground and within the branches and stems of the tea plant as also below ground and within the combs. I have suggested that two or three affected plants should be examined so as to make sure that all the peculiarities are examined, recorded, and specimens col- lected. When this has been done, I shall be greatly obliged if Mr. Winsland will give me a description of his observations and furnish me with the samples of insects, combs, or mud formations characteristic of the Colony. 2. I have gone into these details, since it would seem to me, from recent enquiries in Assam, that we have not only the two forms popularly described in my paper (copies of which have been supplied to you), but possibly two or three more forms. Any suggestions aimed at the eradication of the pest must of necessity follow, no; precede, the determination of the species. So far as my observations go, the "raiding ant" occurs mainly on high land and light soil, in fact, mostly old grass land. In such situations it is not uncommon to find large, oblong hard black structures, as large as the human head, lying half imbedded in the ground. These can be kickec about without being injured, but on being cut open are found to be ant-hives. They are full of a small insect, not unlike the " raiding ant " found on the tea bush. In one garden I picked up the other day a dozen of these hives in half an hour's time, scattered all over a plot of young tea badly affected by the destructive ant. So far I was not able to establish conclusively that these were the breeding homes of the " raiders," but I think that highly probable. If con firmed, it should be the duty of the planter to have all the hives carefully collected and burned. Now, Mr. Winsland would advance HITE-ANTS. mall White- ants. Con/, with Combs Necessary. " Raider " White- ant. Superficial Hives. Con/, with page 38. 368 Report of Investigations in Assam Pseudoneuroptera (Termitidse). TAPE'S Con/, with Account of Ceylon Depredator, page 343. White-ants Kill Tea Bushes. Borer Caterpillars. Conf. with pwra 687. Cure for White-ants. our knowledge of this subject materially if he would be so good as to look for the surface ant-hives or combs that I have described. If not found by him, that would go some way toward showing that they were unconnected with the "Braiders.," If they are found by him, then I should like if he would try and see if he could trace under- ground passages leading from the surface hives to the tea bushes being destroyed. I was unable to discover a queen ant within any of the superficial hives examined by me. This circumstance I am unable to account for, unless the queen be buried in the ground, and thus apart from the superficial breeding hives. If Mr. Winsland finds below the tea bush a hive with combs and queen ant, he would prove that the surface hives were unconnected with the " raiders." So far as my imperfect opportunities have allowed me to prosecute the enquiry.it would seem probable that the " raider ant" has no underground hive, combs or queen. It appears to live almost on the surface of the ground and within the stumps of the more or less destroyed stems and branches. I have thus asked Mr. Winsland to carefully dig out, as it were, two or three invaded bushes by a trench, as described, in order to settle this point. 3. You will see that my knowledge of this subject is too imperfect to justify me giving any positive assurance of our being able to eradicate the pest. That white-ants do actually attack and kill tea bushes, more especially young tea or shoots from collar pruned tea, I have no manner of doubt. You are aware, however, that many planters of long experience refuse to allow this, and say that when the ant appears to be doing damage, it is only a natural consequence following on the death of the bush or shoot caused by the borer caterpillar. There need be no doubt on this point. The ants are dormant during the dry season, and commence depredations towards the middle and latter half of the rains. Before they have resumed operations, therefore, all healthy bushes in an affected area should be carefully watched. The borer drills a neat round hole into the lower portion of the stem or branch, and its presence may generally be discovered through the little dung heaps that are seen to collect on the ground near the entrance to his borings. In gardens badly affected by white-ants, as much as 20 or 30 per cent, of the bushes may be seen injured ; and surely so high a percentage of borer- worms could easily be discovered, since each year they very possibly attack new plants or new branches. That is to say, each individual does not live much over 18 months if so long. 4. I believe the most rational cure for white-ants will be found to be (a) Thorough cleanliness ; by which I mean, all mud deposits systematically removed, accompanied with deep and repeated hoeing. (b) When the bushes have been severely injured, collar-prune. (c) When collar-pruning has to be resorted to, it should be not less than i or 2 inches below the surface of the ground never above. Tea Pests and Blights. 36? White-ants. ondal Paint Harmless. ( leaf or i ift tea per acre for the whole month. The cost of treatment amounted to R8-4 annas per acre, so that with tea at 6 annas per pound all expenses would be recovered in two months." So long as the expenditure for 50 or 100 acres out of an estate of, say, 800 to 1,000 acres, might be put as the maximum required to check the distribution of the pest all over the estate, then insecticide treatment would not only be practical, but urgently demanded. But if the same plots of tea had to be year after year so treated, the point would be rapidly reached in which sulphur would no longer serve the additional purpose of a useful manure, but would become positively hurtful. The treatment of red-spider and other mites with sulphur has been pursued in Europe and America for a very long time, and the adoption of the practice in tea planting is thus fully justified. Mr. Bamber explains the action of the insecticide in the following passage : " Dusting the leaves, when moist with sulphur, has been tried in Darjeeling District on a large scale, and with apparent suc- cess, the sulphur being probably slowly converted into sulphurous acid by the action of the air, which is poisonous to plant and animal life. When washed off the leaves by the rain, it would slowly be- come converted into sulphuric acid in the soil, where it would be utilized by the plant to supply the sulphur required for certain of its constituents, as legumin, which forms one-fourth of the dry substance of the leaf." On the subject of the action of sulphur on red-spider, Mr. Green writes me that he has doubts as to its value. In certain experiments which he performed, the insects, though closely observed, were not found to be affected. Mr. Green then adds, "I believe strongly in soap mixtures, but I think the soap is the active principal in them all, causing death by suffocation." 737. But from my standpoint, if a blight or pest recurs time after time on the same plot of tea or similar plots of tea, it is time to look * This qualification is due to the fact urged by the Cachar planter in his report generally, that the portion? of the estate invaded by the pest are usually the most inferior and least productive. C, W. RED-SPIDER. Yield Increased. Limitation of Insecticide Treatment. Recurrence of Pest. Probable Action of Sulphur. Sulphur is Doubtfully a Specific. Con/, with para. V.'f. Recurrence of the Pest. 384 Report of Investigations in Assam Arachnoidea (Acarinae). TETRANY- CHUS BIOCULATUS Prevention not Cure. Predisposi- tion. Uprooting and Replanting. Doctrine of Insecticides, Sea son of Application. Presumed Position of Hibernation further afield than to a palliative treatment, such as the acceptance of an annual expenditure for sulphur. There is something materially wrong either in the soil, in the drainage, in the ventilation, in the general health of the stock, or in the class of stock itself, on such plots of land, that imperatively dictates prevention as both more effectual and more economical than cure. We must seek for the cause of the predisposition to pests and deal with that. In this search after pre- vention the pest itself will be more effectually dealt with at its weakest stage, but we must discover that stage in its life history. In nine cases out of ten I believe that the bad jat bushes or old and unhealthy clumps in which red-spider and other pests are invariably seen to take their origin, would be most economically treated by being uprooted, the land thoroughly deep soil drained and replanted with better jat stock. In my opinion it is a dangerous state of mind to accept the doctrine of insecticides as the cure for all the ailments of the tea plant, or even as practicable with a visitation that has taken possession of, say, hah' a million bushes at one and the same time. We have to deal with very different conditions to those of agricultural crops and orchard cultivation of Europe and America, and what may be practicable with these becomes in many cases wholly inapplicable with tea. 738. It is in these respects then that I qualify my acceptance of Mr. Christison's views on the treatment of red-spider with sulphur. As indicating a side issue, I would give here a further passage from the Cachar report, published in Mr. Cotes' Insects and Mites, etc. The writer says " Now that I know more about sulphur and its effects, I am convinced I . made a great mistake in not applying it immediately after pruning. I have several reasons for saying so amongst which are (i) Red-spider must hibernate somewhere in the bush ; it cannot come spontaneously. One invariably sees it start on the old leaves, and work gradually up to the new growth which is always the last attacked, and I should not be surprised to learn that it remained through the cold weather in the bark. Therefore an application of sulphur in January ought to be as successful as in March. (2) The sulphur would go very much further on newly pruned bushes, and would also search out the bark, which it cannot do after the leaves form a covering. Moreover, there would be no fear of heavy rain for at least two months, nor would there be the Tea Pests and Blights. 385 The Tea Red-mite. high winds of February and March which waste a good deal of sulphur. (3) Although Mr. Cotes is not convinced on the subject, I still hold to my opinion that sulphur has an influence on blight " ("mosquito). 739. Now it will be seen that, in the action on red-spider and the supposition of a similar benefit on mosquito, the writer must be sup- posed to presume that both pests hibernate on the bushes. If they do not do so, all his other arguments are meaningless. But why should we be ignorant on so all-important a point ? Surely there would be little difficulty in having an isolated bush, or a few bushes, infested with the spider, carefully enclosed in a very fine wire-gauge house, for eighteen months or so, and carefully cut off from all external influences by being fenced in or cut off by a deep trench. If the pest returned to these at the same time as on the bushes left outside, we should obtain a fairly strong corroboration of the views advanced. Then again a powerful lens should suffice to discover the red-spider sheltered on the bark if that be its mode of hibernation. It would only be necessary to sit down on the ground (say in December or January) in the middle of a plot of tea that had been badly infested the previous Spring, and bring one's eye, by means of a lens, into a close inspection of every little detail of the bark, in order (after one or two futile endeavours.) to at last discover the lethargic creature or perhaps its eggs, reposing under some little shelter or below clods or stones on the ground, underneath the bushes. In this case the hibernating condition is not so small, but that it can be discovered, and in Europe it has been so detected. The red-spider of the gooseberry bushes has been found to hibernate in the crannies of rough bark and that of the vine under the shelter of stones. All that is necessary to prescribe when and where palliative treatment can be most effectually applied, is a knowledge of the life history of the pest. Without that knowledge, blindfold experiment and theory must prove both expensive and unsatisfactory. It is on this account that I have laid so much stress on the opinions advanced by many planters as to advantage obtained through late pruning. If we can demonstrate these opinions as well-founded, we get another indication of a more rational and more effective treatment than with insecticides. 740. But to conclude this brief review of the opinions that exist on the subject of red-spider and its eradication, I may here give Mr. Chris- tison's method of sulphur treatment" Our process of application," ED-SPIDER: "WBP Action on Mosquito. Experiments to Prove Hibernation. Late Pruning. 386 Report of Investigations in Assam Arachnoidea (Acarinae). TETRANY- CHUS BIOCULATUS. Bushes First Wetted. Sulphur Dusted on the Wet Leaves. Lime. Muddy Water. Adhatoda. Con/, teith $(l*292, 673. 589, 704, 758 and 795. Tomatoes. Keroslr.e Emulsion. Expediency. Con/, with para. HO. he says, " is simple and inexpensive. We put sulphur in gauze bags or cloth of open texture, and after wetting the bushes thoroughly over and under the leaves, and the branches and stem, the sulphur is dusted over the whole bush by shaking the bag with its contents over it. With a dry spell of weather and no wind, the garden will remain yellow for weeks which is most desirable." 741. In addition to sulphur, lime dusted or white-washed over the branches and the stems, shortly after pruning, has been strongly advocated by many Assam planters as quite as effectual a treatment and in its secondary action as a manure more valuable than sulphur. 742. Syringing with muddy water was tried in Cachar, and proved in one respect effectual, namely, that it killed the mature spiders, but was altogether useless against the eggs. An infusion of Adhatoda is instantly fatal to red-spider, and it has by no means been proved that this might not be as effectual, it certainly would be less expensive, than sulphur. Similarly a preparation made from the leaves, stems, etc., of the green tomato would be beneficial, but it would have to be repeated time after time till each and every brood had been destroyed. The objection to the sulphur treatment,* as recommended by Mr. Christison,is its needless expense. The bushes have to be thoroughly damped before the sulphur is applied. The act of damping might in itself suffice if Adhatoda or Tomato infusion were added to the water. In Europe a soap and kerosine emulsion is that most generally employed, and the reports reviewed by Miss Ormerod in her Report of observations for 1896 show that the emulsion is most successful. 743. It may perhaps now be understood that it is the expense and difficulty to deal with a million or more bushes simultaneously that is the chief drawback to insecticide treatment, when once a pest, such as red-spider, has taken a firm hold of an estate. But it has no right to be allowed to obtain that supremacy. The insecticide materials and appliances should be at hand and used promptly on first appearance. Accidental visitations would thereby be at once checked. But until we are in possession of the full facts of the life of each pest, as also of the physical, chemical and vital influences that check or foster their development, we are not in a position to deal with them satisfactorily. * I am led to understand that Chiswick soap is a preparation that con- tains a large amount of sulphur. If that be so, its application might save the necessity of first wetting the bushes (Conf. with para. 736). G. W. Tea Pests and Blights. 387 A Red-spider Found on Under Side of the Leaves. 93- (c) Tetranychus, sp. (Reg. No. 99.) 744. At Bor Phukri on the I2th July, I discovered what I take to be an undescribed species of Red-spider, belonging very possibly to this genus. It was in many respects very similar to the common form only considerably smaller and of a more uniform scarlet colour with a soft woolly appearance. It was universally found feeding on the under surface of the leaf (instead of on the upper), and it spun a small web near the base of the leaf to which it ran for protection. The larvae, which I presumed to belong to this form, were seen to be at first quite transparent, but gradually to obtain two circular red spots one on either side of the rounded and swollen body, otherwise they were quite colourless. They had six legs, while the adult form had, like the ordinary red-spider, eight. 745. DEPREDATIONS. This form lives on the finer jat plants and on the young leaves, the third to the fifth (from the bud) never upon the old lower leaves. Instead of being bronzed, the leaves turn at firs pale-coloured, almost white, but in time the base and margin, corre- sponding approximately to the portion over which the web is spread withers, changes colour, and finally turns dark brown. The flushing stops entirely, and a very unhealthy appearance of bush supervenes. I subsequently came across this pest on one or two other occa sions as, for example, at Mijikajan and Seconee. Fortunately, on each occasion, only a few bushes were affected, but I can well believe this might prove a more destructive pest, were it to become at al prevalent, than even the ordinary red-spider. Since the date of my personal explorations in Assam I have hac sent me from a garden in Sibsagar leaves, brown at the base and with colonies of the immature transparent mites each with two circula red lateral spots, so that I am led now to think this mite may be gradu ally becoming established. (Con/, with page 390 especially foot-note} 746. REMEDY. I would recommend attention being given to thi subject, and every effort made to stamp out this new tea pest. Syring< the bushes with an infusion of Adhatoda or a weak soap an, kerosine emulsion. Hard plucking and the instant destruction c the pluckings might also prove beneficial. 94- (c) Typhlodromus carinatus, Green. THE FIVE-RIBBED TEA MITE: THE PURPLE AND WHITE MITE. (Reg. No. 84 ; botanical specimens No. 25 A Invades the inest Assam Indigenous. ANEW ED-SPIDER. Feeds on Under Surface of Leaf. Is Probablr Becoming Established. Emulsion. 'IVE RIBBED TEA MITE . Conf. with para. 4i). 388 Report of Investigations in Assam Arachnoidea (Acarinae). CA ATUS. Found on Assam Indigenous. Differences. Assam and the Duars. 747. HISTORY AND DESCRIPTION. This mite was first discovered in Ceylon by Mr. Green, and met with it in the nursery as well as on the plants in the tea estate generally. It was found by me all over Assam, but only on the indigenous or better class hybrids. I never came across it on the China plant. For the present I have accepted the insect found by me as iden- tical with that of Ceylon, though, on comparing some samples kindly furnished by Mr. Green, the Indian form would seem to differ very slightly in the shape of the head and the lesser prominence of the marginal waxy folds. In the Ceylon form the adult mite is of a dull-purple colour with five white ridges, of a waxy material, running along the back, and a small ridge surrounding an hour-glass-shaped space at the front of the body (Green). In the Indian form the mite is almost quite elliptic in outline, is of a bright purple colour, and has three very prominent dorsal waxy ridges with two lateral additional ones inconspicuous, also the front portion of the body, which, for convenience, may be designated the head, is cut off by a straight transverse line and does not appear to form the hour- glass-shaped portion described by Mr. Green. In other respects the two forms, when compared side by side, seem identical both as to size, larval condition, method of throwing off the skin, and system of depredations on the tea. 748. In Assam I found this mite fairly prevalent, especially in asso- ciation with the form described below, and which I have designated the pink-mite, but nowhere to such an extent as to specially attract atten- tion. Since my return from Assam, Messrs. McLeod & Co. have, however, forwarded to me one set of samples, and Messrs. Duncan Brothers & Co. another, both from the Duars. From the corre- spondence that has ensued, I am led to understand that this mite has in that locality assumed the condition of a serious pest. But let me add I have only seen the bronzed leaves with the cast-off skins, not the perfect mite, so that I am by no means satisfied that the Assam and Duars forms are identical. Indeed there are certain peculiarities that would point to their being distinct, though undoubtedly closely allied. From the practical point of view as tea pests, they may be regarded as one and the same. 749. DEPREDATIONS. Mr. Green tells us that, "It produces much the same result as red-spider : the leaves of the attacked plant Tea Pests and Blights. 389 The Purple and White Mite. become dry and bronzed as if sun-burnt, but they retain their shape, and do not curl up like those affected by the red-spider. If closely examined, the leaves are seen to be thickly dusted with very minute white specks, the cast-off skins of the insects, but the mite itself is so microscopic and dull-coloured that it is quite invisible to the unassisted eye. Unlike the " red-mite "* the " ribbed-mite feeds both on the upper and under surfaces of the leaf. The colonies seem to spread themselves evenly along the margins, leaving the centre of the leaf comparatively free." " It has its periods of increase and decrease, but these do not necessarily correspond with the fluctuations of the other species." 750. The following passages taken from the letters which accom- panied the Duar samples may be here quoted : " This blight is only on the bushes of the Singlo Hill plants and looks very much like bad red-spider, only that there is not a specimen of that insect to be found in the garden." (Letter, 7th May.) In a further communication the same writer says, " I am afraid this blight is here getting serious. It is covering now something like 250 acres, of 1893 planting. All the Singlo Hill and Jaipur plants are affected with it badly. Amongst the Manipur plants I have so far noticed only a few bushes. It started in the Assam indigenous plants, and these are looking browner every day. The rain we have had, I thought, would kill it ; but it seems, on the contrary, to be getting worse." (Letter, 21 st May iSgyC) On the 8th July the same writer reported that the blight " seems to be getting less in the older portion of the garden, but it is getting worse on the younger plant." On the isth he again wrote that all the affected leaves were falling off the bushes, but that, as the old ones fall off, the pest ascends to the new leaves. On the ist Septem- ber 1897, he finally reported "nothing more of the blight is to be seen now except on opening out the bushes, one can see the bare stem without any branches as far as the blight affected them and some fallen-off blighted leaves, hanging in the forks of the branches. The bushes look as healthy and fine as they ever did." 751. Another contributor wrote from the Duars on the 24th July : "I am sending you down by post samples of leaves that are affected with blight from which the bushes suffered so much during last * The Red-spider of this report. G. W. , EM .R,BBE D Sun-burnt Leaves. eeds on Both Sides of the Leaf. Period of Activity in the Duars. Leaves Fall off the Bushes. Suffered Most in June. 39 Report of Investigations in Assam Arachnoidea (Acarinae). TYPHI DROM CARINA' Two Pests In Association. Cast-off Skins Mostly on j Upper Surface of Leaf. Young Tea. Presumed to have been Imported from Assam. Con/, toith History* Red-split er t fora. 718. month. I would be glad if you have these examined, and let me know what kind of blight it is. On examining the leaf through a glass I find it covered over with a very minute insect, very like white bug. The leaves affected with this blight turn brown and eventually fall off. I am also sending you leaves with parts quite dead, the leaf appears otherwise quite healthy. This blight only seems to attack young seedlings, very few of the larger bushes having any signs of it." Subsequently in acknowledgment of my report on the samples, the following reply, dated i6th August, came to hand through the agents : " I am inclined to think there are two distinct blights.* The one in which parts of the leaf become dead or rotten, while the remainder, to all appearance, is healthy, but in a great many cases have a mottled appearance. This may be the blister blight that Dr. Watt refers to. The whole bush eventually assumes a yellow and sickly look ; in the other case, the leaves commence by getting brown all along the edge. This works inward till the whole leaf has assumed a brown colour, with white scales all along the sides of the midrib and veins. The leaves so affected eventually drop off, leav- ing the bare stems. It greatly retards the growth. The two-year old bushes have to a large extent, been attacked with it more or less since November last, but it became very bad during the month of June, after which it was less, but is still hanging about. I notice all the young gardens and extensions in older ones, around this district, have been attacked. I am inclined to think this blight has been imported in the soil in which the seed is packed and sent down from Assam. I have never seen it in this district before." 752. The suggestion that this new pest may have been introduced to the Duars from Assam, by the soil used to pack seed, may be quite unfounded, but it is worthy of investigation. As possibly opposed to that idea, I would repeat, however, that there are certain features of the Duars mite that would point to its being a distinct species from that met with by me in Assam. 753. The purple-mite, as I called it, before I had the good fortune to receive from the author, a copy of Mr. Green's Insect Pests of the Tea Plant, exists throughout Assam, as may be seen from the extracts * It may be here explained that it nearly always happens that two ites live in association. It seems thus probable that the preceding iccies (No. 93) may have been found along with the present (Conf. -with mites species (No, para. 781). G, W. Tea Pests and Blights. 39i The Five.Ribbed Tea Mite. given below from my diary, in connection with the pink-mite. In only one or two localities did I meet with it by itself ; it was generally found in association with the pink-mite, and much less abundant than that form, so much so as to lead me at first to suspect it might be the male, and the pink form the female, of the species. At Makum, how- ever, I found the purple-mite under circumstances very similar to those described in the Duars, though the empty cast-off skins were distributed all over the under side of the leaf instead of being arranged on the upper surface and alongside of the midrib and veins the condition in the Duars form. This is one of the most signifi- cant peculiarities of the Duars pest, and one that leads me to suspect that it may in reality prove a distinct species from either the Assam or the Ceylon form. 754. Another peculiarity that may be! here recorded. Certain leaves seem to be specially set apart for the purpose of breeding. On the under surfaces of these leaves will be found numerous thickened patches like little warts. On looking through the leaf these are seen as translucent, pale-coloured spots. It seems likely that, during seasons of drought, when the leaves get the condition often described by planters as "sun-blistered," that this pest is prevalent, the " blisters " being the structures here described. On careful examina- tion they [.will be found to be cavernous formations within the tissue, just below the epidermis, and contain what I take to be the eggs of the purple-mite. Apparently the mites on escaping from these blister or wart-like houses wander off to other leaves to feed, and it would seem that on molting they congregate under the shelter of the veins on the upper surface. As a consequence the upper surfaces of the leaves, even to the naked eye, appear as if dusted along the line of the veins with very minute particles of pure white powder. These are the cast-off skins, which, in badly affected leaves, may be seen in thousands upon thousands. But I never came across, though I looked carefully over many samples, a waited or blistered leaf bearing also the powdery deposit of cast- off skins. In the supply sent me from the Duars, there might be perhaps one in ten of the leaves warted and devoid of the powdery deposit. 755. Still another circumstance of some moment may be here recorded. I never met with a leaf in the Duars supply with the Cast-off Skins on the iderSide of the Leaf. Blisters on the Leaves Possibly Breeding Houses. Sun-blistered Leaves. Cast-off Skins Like White Powder. Depositejon Surface. 39 2 Report of Investigations in Assam Arachnoidea (Acarinse). cast-off skins on the under surface of the leaf. In several instances, however, I found here and there the dead mites among the cast-off skins, and in consequence feel satisfied that I am correct in referring this pest to the purple or five-ribbed mite, but, as already stated, I have not examined the live mite of the Duars. In the few instances in which in Assam I came across the purple-mite, without finding the pink-mite as well, it was chiefly dispersed over the under surfaces of the leaves, and the empty cases were, as in Mr. Green's Ceylon samples, scattered over the surface instead of arranged under the shelter of the veins. 756. But the history of the Duars pest agrees, in other respects, with the state of affairs that I found in Assam. It attacks the higher jat Assam indigenous teas, and is for the most part confined to young bushes. In fact I do not recollect finding it on plants much older than 5 or 6 years. The leaves turn at first pale-coloured, get dried up, and begin to bronze on the margin, the discolouration extending gradually over the whole leaf until, when quite brown, it falls from the bush. The pest thus advances from the old to the young leaves, and by the time of the monsoons being established the plants are next to leafless. 757. REMEDY. All mites succumb very rapidly to a treatment with kerosine or phenyle. Mr. Green recommends, " one part of kerosine emulsion to eighty parts of water, or one of phenyle to two hundred and forty parts of water." " The nurseries should be watered with the mixture in the evening and with pure water in the follow- ing morning, unless rain should have fallen during the night. This treatment would not altogether exterminate the insects, as some of them are sheltered beneath the leaves, but I think it wo.uld prove to be a wholesome check to the many insect pests in the nursery. But after being pulled for planting, the plants might be dipped in buckets of the mixture, which would certainly free them and give them a fair start in the field. The stem and leaves only should be dipped, not the roots." 758. A dangerous visitation, such as I have mentioned in connec- tion with the Duars, should at the commencement of the outbreak be treated with kerosine emulsion and water or an infusion of Adhatoda, Every bush should be thoroughly syringed, two or three times at intervals of, say, one week. At the pruning season all withered leaves should be carefully cleared off the bushes, and Tea Pests and Blights. 393 The Yellow-mite. the whole plant thoroughly painted over with the emulsion and water. In this way it seems likely the return of the pest during the ensuing spring would be averted. 95 (c) Acarus, sp. THE YELLOW-MITE ; " THE APPLE-FOLIAGE BLIGHT ": " SULKY." (Reg. No. 1 33 ; botanical specimen Nos. lo^gj, 11331, 11929, 11946, 11955 an d I! 99t-) 759. HISTORY. Mr. Green has been good enough to furnish me with a sample of leaves infested with the yellow-mite, which he provi- sionally named Acarus translucens, in his little work The Insect Pests of the Tea Plant. He has also drawn my attention to the fact that the name translucens cannot, however, be given to the yellow- mite of tea, since Nietner had assigned it to a coffee pest that turns out to be a distinct species. 760. I have examined Mr. Green's specimens, compared them with the condition met with in Assam, and while fully satisfied that the Indian manifestation must be caused by some very closely allied mite, think it safer for the present to regard the two as distinct. In fact on the bushes, affected in the manner which I shall presently describe, I could not find the mite, but it seems probable that my failure to do so proceeded from the fact of my being in the tea districts during the season of their inactivity, and that accordingly I was but viewing the deformed leaves and buds of last year's opera- tions. Indeed, until favoured by Mr. Green's samples, it was my intention to have described the visitation without venturing to definitely suggest a cause. At the same time I may remark that, the peculiar felted formation on the leaves had suggested from the very first a felt-mite, similar to those that for some time had been regarded as fungi and described under the generic name of ERINEUM. The careful examination of Mr. Green's samples, how- ever, with the mite on them, and* comparison with the diseased con- dition found by me, leaves no longer any room for doubt as to the Assam plants being destroyed by a very closely allied mite to that met with in Ceylon. 761. On the 7th April, while on a visit to Khumtai (one of the Assam Company's gardens, then badly infested with " Blister Blight"), I discovered a bush here and another there in dark green foliage, through not having started to grow since the date of being pruned, YELLOW- MITE. SULKY. Con/, with para. 4O. Season of Inactivity. Felted Condition. Khumtai. 394 Report of Investigations in Assam Arachnoidea (Acarinae). ACARUS, SP. Sulky. Found Everywhere. Total Loss to the Province. Bushes Never Recover. Chief Cause of Vacancies. Affected Bushes Isolated. All Jats Liable. while the others around were covered with their Spring shoots. I also noticed that the leaves were crumpled on the upper, while on the under surface, near the midrib and for some distance on either side, they were coated with a brownish-red tomentum that gave them the soft woolly appearance of the Spring foliage of the apple tree. On this somewhat fanciful resemblance, (and as a matter of conve- nience,) the name apple-foliage blight was suggested, for this very remarkable disease. I now observe that in Ceylon where a similar condition of bush prevails, the planters call the blight " Sulky "a term fully expressive of the attitude assumed. 762. Having once had my attention directed to this very remarkable disease, I practically found it in every garden throughout the Prov- ince. In some there might be as much as 5 per cent, affected, in others perhaps not more than one half per cent. Still the disease occurred everywhere, no garden could be said to be absolutely exempt from it. It is, however, most prevalent in Sibsagar Dis- trict, comparatively rare in Dibrugarh and Nowgong : while, on the North Bank gardens, a slightly different form (No. 11946} occurs, so that I presume there may be several species of mite that all produce very similar distorted and diseased conditions of the bush. When it is added that bushes affected in this way make no attempt to flush until July at earliest, or perhaps not till August or September, some conception of the total loss to the province can be obtained. And even when they do flush, the amount of leaf secured is hardly worth plucking. So far as I was able to discover, bushes once affected with this blight never recover, but get worse and worse until finally they are killed. Indeed I believe this pest is one of the chief causes of the vacancies that are to be found all over most gardens. One very striking peculiarity, which I had noted while in Assam, and which I see is true also of the Ceylon pest, is the fact that the dis- ease does not originate from a common centre. A bush here and another there may be affected without apparently having anything in common. It is certainly more prevalent in old, than in new, gardens, and on unhealthy, rather than healthy, bushes ; but I have found it on seedlings in the nursery, on China bushes, on hybrid bushes, and on the finest Assam indigenous. All alike are liable to this visitation without there being afforded the slightest indication of any means of communication from the one to the other. Indeed, I may safely say Tea Pests and Blights. 395 The Apple-foliage Blight. this disease puzzled me more than any other in Assam, and curiously enough I came across no planter who had allowed himself to recognise the plants so affected as being diseased. On my drawing attention to them, I got the almost invariable reply that they were sulky bushes arid, from year's end to year's end, had done nothing. That opinion I have, as already stated, had reason to believe to be quite correct ; once infested the bushes never throw off the blight, but each year get worse and worse. They have been heavy pruned by some planters, but, unless collar pruned, the disease resumes its activity. I was told of the effort having also been made to force the bushes by heavy plucking, but without any beneficial result. Usually the planters have assured me that, while they knew the bushes were useless, nothing short of uprooting could be of any use, and, to pro- pose to uproot such a large number of plants, would be to court a severe rebuff from their owners. There was nothing for it, therefore, but to cultivate the ground around these sulking useless bushes, to prune them at the same time as the others, and to be content with such returns as could be obtained from them. 763. DESCRIPTION. The above remarks may, I trust, suffice to bring to mind the disease to which I here allude, for not only are the bushes being slowly killed by a pest, but by one that fortunately will yield more readily to treatment than almost any other in the tea garden. The following descriptive account of the form met with in Ceylon will be of interest to the Indian planters : " This species," writes Mr. Green, "feeds on the flush: the living insects can be found only upon the- bud and the under sides of the two following leaves. As each bud opens, the colony moves higher up, deserting the older leaves. But these latter are permanently injured, and always retain the marks of the disease. The distinguishing sign is a roughened surface and brown stain extending for some way on each side of the midrib ; sometirles covering the whole of the under side of the leaf, but generally confined to the central portion. Some- times again, there is a brown crease between the margin of the leaf and the central diseased part looking like a supplementary rib on each side of the median one. This crease results from the attacks of the mite upon the unopened bud, while the edges of the leaf are still folded inwards. The diseased leaves never attain their full size ; they lose their natural gloss, become hard, puckered, and give SULKY. Not Recognised by the Planters as a Disease. Severe Pruning and Plucking a Failure. Uprooting. Mite Found on the Bud and Young Leaves. Leaves Permanently Injured. Con/, with paras. 6O3, 605. Brown Stain on Underside. 396 Report of Investigations in Assam Arachnoidea (Acarinae). ACARUS, SP. Young Mite. Adult with a Useless Fourth Pair of Legs. Male Mite. Extent of Distribution. Khumtai. an unhealthy appearance to the whole bush that is very noticeable. After a prolonged attack the bush becomes smaller and smaller with little spaces between the leaves ; and finally the tree refuses to put out flush shoots." " The individual insects are so minute as to be invisible without the aid of a magnifying glass. Under a good microscope they may be distinguished, in all stages, crowded upon the youngest leaves at the tip of the shoot." " The young mite has only 'six legs and is of a sluggish disposi- tion. It is of a very pale-yellow colour with clouded whitish stripe along the middle of the back. It seems to undergo only one moult before assuming the perfect stage." " The adult female is of a clear amber colour, with a smooth glistening skin, and with a clouded dorsal stripe, as in its larval stage. It has now an additional pair of legs, but this fourth pair is carried, apparently, more for show than use. They are much thinner than the others, and terminate in two bristles of unequal length." " The male is so unlike both the young and the adult females that I should have thought it to be a distinct species had I not myself witnessed its transformation from the larval stage. It is of the same colour as the female, with the same clouded dorsal stripe, but it is of a very different build. Its legs are more powerfully developed. The hindermost pair, though not used in locomotion, are stouter than the others, and probably act as clasping organs. They are armed with a strong curved tooth on the inner margin, and a long whip-like bristle on the foot. The six locomotive legs each terminate in a bilobed pad, and the first two pairs bear a knobbed bristle upon the outer margin." 764. Depredations and Extent of Distribution. The following passages from my diary may help to more fully exemplify the nature of this pest, and manifest the extent to which it is distributed : 765. Khumtai, ith April 1895. Several bushes, seen with the leaves dark green, crumpled and wavy on the margin, the upper surface being puckered, for a certain distance on either side of the midrib, a condition that corresponds to a felted coating below, similar to what is commonly seen on the leaves of the cotton and many other plants. Similar formations were formerly described as species of fungi, under the name of ERINEUM, prior to their being proved to be epidermal growths caused by the irritation of mites. Failed to discover the mite, and as there were no young buds, presume the Tea Pests and Blights. 397 The Yellow-mite. leaves examined show the after-effects of last year's depredations of a mite that may probably return later on in the season. (Ncr. 1049?.*) 766. I had the pleasure of a walk through garden and a conversa- tion with Mr. G. on the i2th April. I pointed out to him the disease I have provisionally called the Apple-foliage blight. Many plants were seen to be completely destroyed by it, and others not flushing, and with the young twigs that had appeared covered with the pink scale-like formations characteristic of this remarkable disease. It is by far the most serious visitation in this garden. In an area of 20 square yards, as many as six diseased plants were counted. These had formed no new leaves since pruning, and every bud and leaf present had been thickly coated with the scale-like tomentum. The young shoots had been killed '(no fresh shoots visible), otherwise plants were healthy and well formed. They had the appearance of having been severely and suddenly arrested in their growth. The specimens collected show the ultimate stages in which the tips of the branches indicate a continuous interruption to the formation of shoots, the shoots having been dwarfed in bud. The percentage of death from this cause seems very high. In the very finest part of the garden where the bushes are seven years old, and perhaps 4-5 feet in diameter (never collar pruned) and sterna healthy, there might be 2 per cent, killed outright, and in some places even more. Not one of the bushes still alive have pro- duced a leaf since they were pruned last autumn, and a very large number of bushes were seen in this latter state. Though I examined them with the utmost care,. I could not find any of the mites that I presume to be the cause of this stunting of the plant and felted con- dition of the leaves. 767. Ligri Pukri, April i4th. Showed the manager a fair num- ber of bushes affected with the apple-foliage blight. He agreed to my proposal to collar prune a certain number, fire in the manner proposed by me a similar number, and mark down a third set to be left alone in order to see if they threw the disease off, and to decide whether collar pruning or firing was the better treatment. 768. At Atkhel I observed (April iQth) that, plants with the apple- foliage-blight, very generally have the bark and stem just below ground soft and pulpy and of a brown or red colour instead of being of a healthy greenish brown. Suggested that a selection of the plants should be fired and a comparison carefully preserved between these and others left as they are. In a garden in Jorhat Division, visited 24th April, I found a very large percentage of apple-foliage blight. This was somewhat strik- ing since a few miles off, at Amguri, I practically failed to find an example of this most mysterious of all diseases. In new plantation about one per cent, of the three years old bushes had the apple-foliage blight, none of the old ones had it. SULKY. Nazlra. Arrested in Growth. tenot TSZ Ligri Pukri. Con/, with para. 778. Atkhel. Con/, with next page. Jorhat. 398 Report of Investigations in Assam Arachnoidea (Acarinae). ACARUS, SP. Moaband. NIgiriting. Dum Duma. Makum. Panitola. Bordeo Bam. 769. At a garden visited on the 25th April in the Jorhat Division, a fairly large percentage of the apple-foliage-blight was seen in new plantations, less in the old. At Jorhat on the 26th April, I saw many samples of apple-foliage- blight, the bushes in all stages of decay, and many dead. The disease was in fact extremely prevalent. 770. At Moaband, April 28th, the bushes affected with the apple- foliage-blight, showed the buds aborted, all the leaves having fallen off. In consequence short distorted leafless buds were found amid last year's large leaves, but no flushing shoots. The aborted buds were seen to be densely coated with rufus scales similar to those on the leaves, but the mite, which I presume to be the cause of this diseased condition, could not be found. (No. 771. At Nigiriting, May 2nd, the apple-foliage-blight was found fairly plentiful, in the older portions of the garden. At my sugges- tion a large number of the bushes were to be fired as the best remedial measure. (No. 11991.) 772. At Dum Duma, Dibrugarh, June 27th, a few bushes found with the apple-foliage-blight. (No. 7/9.29.) 773. At Makum, I found three plants with the apple-foliage-blight and one which might be described as a seedling. This garden is now (1895) only four years old, and is perhaps 20 miles distant from any other garden. 774. On the 1 8th June, while on visit to Panitola and neighbouring gardens in the Dibrugarh District, I found the apple-foliage-blight to be rare. While showing this disease to some planters I was handed a letter from Mr. Gair, of Atkhel (Sibsagar District) in which he informed me that the bushes with apple-foliage-blight that had been burned at my suggestion, on the iQth April, had flushed freely, far better in fact than the others, that as a parallel experiment had been severely pruned. Further that they showed no signs of a return of the blight. Burning, therefore, would appear to be a most effectual cure for this very remarkable disease. 775- July 5th, Bordeo Bam, North Lakhimpur, came across a slightly different form of the apple-foliage-blight. All the twigs and shoots were densely covered with rufus scaly tomentum. This extends up the peteoles and often covers the whole under surface of the leaves. In other cases the leaves show two diverging lines of scaly tomentum extending from the base to the apex of the leaf, similar to that pro- duced by CEYLONIA. The plants were entirely arrested in their growth, and even to present date had thrown out no new flushing shoots. Could find no insects or mites on the leaves or branches nor in the buds. (No. 11946.) Tea Pests and Blights. 399 The Apple-foliage Blight. July 6th-8th, Patalipam, apple-foliage-blight known, but not very abundant. 776. REMEDY. Mr. Green says, "Excepting the bark-louse (Aspidiotus, No. 72 above), I consider this 'Yellow Tea-mite' to be one of the most serious pests we have to deal with. Protected as it is by the downy hair that clothes the under surface of the young leaves, it is unaffected by heavy rain and continues its ravages uninterruptedly throughout the year. As it is confined to the flush, the persistent plucking of every shoot on such diseased trees, ought to remove the cause of the disease. The flush is usually so hard and banjhi that it is apt to be passed over by the pluckers. After pruning one of these ' Sulky ' trees, the prunings should be at once removed and des- troyed. In fact I think the systematic destruction of all prunings while still green, either by burning them in situ, or by removing and burning them would of itself prove an immense check to the insect pests of all kinds." 777. From what I have stated of my failure to find the mite, from April to June, it may, I think, be accepted that in India this mite is not in activity throughout the year. It is probable that it may exist within the unexpanded buds (during the months named), but, if external, it must be very few in number. In this respect, then, the Indian mite differs from that of Ceylon. But its depredations are evidently so serious, during the months of activity, that it takes some time for the bushes to recover. In Ceylon, Mr. Green informs me, pruning can be done any month during the year, and that accordingly this pest can be dealt with by delaying the pruning to the season at which the entire affected branches and shoots may be removed. To treat the Indian plant on that plan, pruning would have to be delayed till August very possibly, and might then prove fatal to the bush. It was on these lines that I reasoned out that there were two possible methods of treatment, viz., (a} to collar prune all bushes affected by this pest, and to at once burn the prunings, or (5) to fire the affected bushes, say, in March. The latter course I recommended to many planters, and in the extracts from my diary above have already mentioned the result obtained in one experiment. The bushes were entirely freed from the pest, and flushed freely very shortly after. While in the Dibrugarh District I mentioned this fact on several occasions, and one planter tried the experiment on two bushes, both SULKY. Patalipam. Continues Its Ravages Throughout the Year. was Burning Prunings. Depredations Serious. Pruning as a Remedial Measure. Fire the Best Method. Con/, with paras. 641, 49. 767-8, 77J, 778. 400 Report of Investigations in Assam Arachnoidea (Acarinae). ACARUS, SP. Firing Should be Done in Spring. Report of Results with Firing. Pruning. Certain Cure PINK-MITE Con/, with died. But he fired them in June and thereby confirmed an opinion that I had freely urged, that fire, as a treatment for pests on tea, must never be resorted to during the time the sap is circulating freely. If that restriction be neglected, the shock to the plant is so severe that, if it be the least sickly, it will, in the majority of cases, be killed. 778. In the passage from my diary (quoted above, page 397} regard- ing Li gri Pukri, it will be seen I proposed a comparative trial, with one set of apple-foliage-blighted bushes to be fired, the second collar pruned, and the third marked for comparison with the other two sets. The fol- lowing report was subsequently furnished by Mr. J. A. Thomson : " The apple-foliage-blight experiments are going on all right. The plants that were burnt sprouted away much faster than those collar pruned, and the shoots are strong and show no signs of disease, but, if the plant required collar pruning at any rate, I would prefer to use the saw, and only burn those that had been collar pruned already. I burnt bushes that had been collar pruned some years ago all over the garden, here and there, and the result is very satisfactory. I fancy for one thing that the ashes from the stuff used for burning acts as a manure. The bashes not pruned nor burned, are just managing to live, but have not given a single leaf fit to make tea." 779. It will thus be seen that, if bushes affected with this most destructive pest are marked out to be collar pruned in Spring, where that is considered desirable, or fired where collar pruning is not necessary, we possess a certain cure. No tea garden in Assam need have a single bush " sulky " and unproductive from mite infestation, if the sugges- tion here offered be accepted. The few bushes that may die were worthless, and the space they occupied should be regarded as more valuable than their presence. In my opinion firing is peculiarly applicable to this pest. When the apple-foliage-blight appears in the nursery, the treat- ment suggested by Mr. Green for the purple-mite should be pursued (see page 392}. 96. (c) Phytoptus these, sp. nov. THE PINK-MITE. ( Reg. No. 67. ) 780. HISTORY. During my explorations in 1895, through the chief tea districts of Assam, I was taken to a clump of tea supposed to be Tea Pests and Blights. The Pink-mite. badly attacked by green-fly. Instead, however, of the leaves being dark green, erect and folded or crinkled in the peculiar manner said to be characteristic of green-fly, they were very pale- coloured, almost white, dry, convex above, with the margins and veins of a pink colour. In what could at once be seen as an advanced stage, the leaves were almost bronzed, from the extension of the pink tinge over larger portions of the leaves, but they did not appear to wither and fall off the bush. 781. A little examination sufficed to reveal these plants as suffer- ing from a pest with which I was then unfamiliar, but which was clearly quite distinct from green-fly. Under the lens the leaves were observed to be covered with thousands of a very minute mite which, in the adult state, was of a pink colour, hence the pink tinge to the leaves. These mites were further noted to be most abundant on the margin and along the line of the veins. Though very abundant on the upper surface of the leaves, they were also found below. But it was curious to observe that about one in every hunderd or so was of an entirely different shape and of a purple colour. The latter I sub- sequently identified as a distinct species,* though met with in associa- tion with the pink-mite. The association of two or more minute pests together, is one of those extremely difficult problems that seem almost incomprehensible. This is peculiarly troublesome in the study of scale-insects and mites, in which very nearly invariably two species are found in intimate association and have repeatedly been mistaken as the males and females of one species, instead of being two entirely distinct forms. 782. DESCRIPTION. Seen under a fairly powerful lens, the adult pink-mite is a linear oblong creature, broadest near the head, and gradually tapering to the tail. It may be described as being about icoth part of an inch in length. It walks about in a curious attitude, with the head carried at a higher level than the tail. In moving it also twists its body, being apparently aided in progression by a sucker- like process at the anal extremity. The legs are two pairs, placed in the front of the head and directed forward. They are three jointed and have two minute hairs at the joints. Under the micros- cope the body seems to consist of four sections, one a somewhat * Typhlodromus carinatus, Green. Coloured, Ultimately Mistaken fop Green-fly. Two Species Association. Cow/, with, page 39 O. Adult Mite. Position an Number of Legs. 26 402 Report of Investigations in Assam Arachnoidea ( P hytoptidze) . vro Description of the Mite. Immature Mite. Absence of sence Eggs. Warts on the leaves. FIG. ii. THE PINK MITE. triangular terminal portion that may be designated the head. The next two are sections of the body proper, and the fourth the anal extremity. This is furnished with what appears to be a retrac- tile sucker, by which the mite can fasten to the leaf and raise the other portions of its body, jerking and propelling its self about. But it would seem as if the entire body were made up of a large number of folds which, seen on the outer circumference, give the appearance of a toothed margin. Down the centre of the body a faint line is discernible which near the middle of the two central divisions swells into a circular spot. The mouth seems to consist of two mandibular processes with two antennge-like feelers in front. The sketch made from the live insect, Fig. n, will convey some idea of its structure. 783. The immature mites or larvae () are more elliptic in shape and tapered to both extremities. At first they are almost pure white and hyaline. With age they become coloured, the second and fourth sections of the body being darker coloured than the first (or head) and the third or central section. But even in their earliest stages they manifest the peculiar folds of which each section of the body appears to be built up. They seem to molt in the usual manner by throwing off one or two skins before they attain the adult condition. 784. A striking peculiarity of the colonies of this mite is the entire absence of eggs. With -the red-spider, on the other hand, what catches the eye almost before anything else, on viewing a red-spider- infested leaf through a lens, is the immense number and extreme beauty of the eggs, cemented all over the upper surface. But with the pink-mite the margins of the leaf will be observed to be thick- ened and even warted for some distance inwards. These warts or blisters are doubtless the breeding chambers within which the eggs are deposited and apparently also the houses of refuge for the young larvae. Unfortunately, when travelling in Assam, I could not carry with me full microscopic apparatus, more especially a section cutter Tea Pests and Blights. 403 The Pink-mite. so that I was not able, when fresh material was in my hands, to fully investigate the structure of the mite and its method of reproduc- tion. The specimens preserved in spirits of wine have suffered so severely that even the mite itself cannot now be recognised with any certainty. I believe, however, that I am correct in suggesting that this mite is a species of Phytoptus, and that, like all its congeners, it is a felt-gall-forming mite not very remote from Phytpptus pyri and P. ribis, the blister mites of the pear tree and of the blackberry bush. 785. DEPREDATIONS. In the introductory chapter of this report, pp. 29 to 31, 1 have already alluded to this pest. I have there stated that it has largely to account for the pale colour and late flushing of some of the finer jats of Assam indigenous tea. I never came across it on the. China plant, nor even on hybrids, unless of good quality, and it would appear to be rare on the Manipur jat. Apparently it is most frequent on light sandy loams, and prevails to a greater extent during dry seasons than in moist weather. It accordingly occurs early in Spring and gradually disappears as the rains become established. When present to any serious extent, it retards the flushing for several months. But the leaves do not turn brown and drop off the bushes as with the purple-mite. It is more widespread and more frequently present, but is less epidemic (so to speak), and accordingly attracts hardly any attention, as compared with the purple-mite or red-spider. But, I believe, the loss through this insidious pest is far greater than the majority of planters have any conception of. I am not likely to forget the reception I got from the late Mr. Madden, of Panitola. " We are delighted to see you, " he said, " but have no pests or blights to show of any consequence." Have you not, was my reply, then what is the matter with this expanse of pale yellow-green plants all around us? "Oh that is not a disease, but a proof of the high quality of the stock. It is the very finest Assam indigenous, which, you know, is very much paler coloured, and later in flushing than the other jats. In a week or two it will be in full bearing and a magnificent crop may be anti- cipated. " On being shown a leaf, through my lens, literally alive with the pink-mite, Mr. Madden, to my question whether these visitors were likely to be hurtful to the plant, at once admitted that they must injure it materially. 26 A PINK-MITE. Felt-Gall. Pale Coloured Late Flush- ing. Con/, with para. 49. Retards Flushing. An Insidious Pest. Proof of high Quality. 404 Report of Investigations in Assam Arachnoidea (Phytoptidae). PHYTOPTUS THE/E. One of the Most Serious Pests of Assam Jats. Niglriting. Blister Mite. Possible Confusion with Green- fly. 786. I have taken the liberty to publish the above conversation (from my diary), because I think that, had Mr. Madden been alive to permit me to do so, his reply would have been, that it was as well that the repu- tation of pale colour and late flushing should be pointedly demon- strated to be in many cases, but the direct expression of a serious visitation one of the most serious perhaps to which the indigenous plant is exposed. As manifesting the very widespread distribution of this pest, I may give here the following passages from my diary : 787. While investigating the question of green-fly at Nigiriting on ist May 1895, I observed that the young leaves often stood 'erect; that they might be described as folded lengthwise ; that the tips were bent over ; and that in many cases the margins were inflexed. But what was still more curious, the midrib and veins were pink, while the general colour of the leaves might be spoken of as pale greenish-yellow to almost white, the pinkish tinge giving them a bronzed effect. On examining these leaves closely I saw that the margins, midrib and veins were pink mainly on the upper surface. Under the lens this pink colour was soon discovered to be due to the presence of immense multitudes of a very minute pinkish-coloured mite which, when magnified 40 diamaters, was not larger than the point of a needle. It is of a conical shape, pointed towards the tail end, and seemed to walk with its truncated extremity forward and slightly elevated. This creature I have not as yet had time to examine with the microscope, but it looks remarkably like one of the blister mites, and thus possibly allied to the pest on the pear, and other fruit trees in Europe and America. But on making this discovery, an idea at once struck me as being of some moment. I had been taken to this parti- cular plot in order to be shown green-fly. That insect could un- doubtedly be found, but the bent leaves with reflexed margins and the unhealthy state generally, pointed out as indicative of the approach of a bad attack of green-fly, were much more likely to be a consequence of this hitherto undiscovered mite, than to be caused by green-fly. Could a mistake have been made by all previous observers, for I had seen stunted blight without green. fly, and green- fly without any stunting of the bushes ? This point would have to be carefully investigated, but I here repeat that green-fly was found freely on the leaves on which this new mite occurred in thousands almost on each leaf. Of one point I had no doubt, (as soon as I had seen this mite), namely, that it at all events was the cause of the blanch- ing and bronzing of the leaves. But the stunted blight, in its advanced condition, (which I had previously examined), presented many pecu- liarities not observable on the mite-infested plot. The two could, therefore, quite easily be independent of each other, though the early stages of green-fly stunting, might be often confused with the blanch- ing due to this new tea pest. Tea Pests and Blights. 405 The Pink-mite. Mr. Holmes, the Superintendent, to whom I demonstrated, b means of a powerful lens, the presence of this little creature, remarke that those seen on the leaf looked, when so magnified, like a grea flock of sheep grazing over a large field. He was, however, so muc disappointed with the sickly-looking white bushes, in this part of h estate, that he took me off at once to see a new plot of tea, laid ou with Mampur seedlings, where he assured me, all the bushes woul be found of a dark enough green to satisfy my utmost desires in tha direction. He was, however, amazed, as we neared this particula plot, to find that, since the date of his last visit (and for the first tim to his knowledge), all the bushes had turned pale greenish yellow This I very soon demonstrated was due to my new mite, and wewer both of us thus convinced a discovery of great value had been mad that no doubt would account for the late flushing of many gardens. In a garden visited on the 2nd May (in the Golaghat Sub-Division) I found yellow leaves with the new pink-mite common, and th bushes so affected showed green-fly in addition. 788. On the 2nd May, I also examined an extensive plot of the verj best Assam indigenous tea with the flushing arrested and the leave all turned pale yellow. As anticipated from experience lately gainec it was to be expected that the leaves would be found covered along the margin and on the midrib upper surface with multitudes of the minute pinkish-coloured mite. These were observed to move abou fairly actively, and to eat the minute hairs and epidermis of the leaf They are so small as to be absolutely unrecognizable to the nakec eye, except through the colour they give to the parts mentioned. Here and there, amid multitudes of pink-mites, a few dark purple ones were to be seen, with three white bands down the back (Typhlodromus carinatus), and a very large number of still more minute larvae, but no eggs. The pink-mite has a triangularly pointed head portion, and the rest of the body referred to three distinct sections. 1 have not had the time to attempt to trace out the life history of this mite, but it appears to originate from wart- like thickenings on the leaf, which possibly correspond to caverns within the tissue. It is, in other words, probable that the eggs are deposited within the tissue of the leaf and possibly through the stomata, and that the blanching of the leaf is largely due to this circumstance. The breathing functions of the leaf would thereby be interrupted, and the young leaves hardened and dried up as if they had become pre- maturely old. The hardened, curled-up and bronzed leaves, undoubtedly, have been taken by many planters as caused by green-fly. I have had this fact repeatedly verified, since I first detected the mite, and that too in many gardens, where the planters, on being challenged, failed to produce a single example of green-fly in support of their statement that their gardens were suffering from that pest. When these mites PINK-MITE. Found on Manlpur Jat. In Golaghat. Purple-mite. arts on the Leaves. 4 o6 Report of Investigations in Assam Arachnoidea (Phytoptidae). are on the leaves, the margins are inflexed (that is to say, turned over the upper surface), rarely reflexed. They stand up in the way attributed by planters to green-fly, though in this ascending attitude it is generally affirmed the green-fly-infested leaves are of an excep- tional dark colour. If that be so, then we have one marked differ- ence between the two pests. 789. On my return to Nazira on the nth June, I found the pink- mite very abundant, especially on some reclaimed land. It was not so abundant, as recorded, further down the valley, but doubtless that was due to the rains having been fairly established, by the date of my return visit. The plot on which I found it, was backward, owing possibly to the severe pruning on its being reclaimed. The contrast between this yellow-leaved sickly portion and the rich green of the adjacent healthy parts was very striking. Both the pink and purple- mite were found, though the latter was extremely rare. 790. At Panitola I found a large percentage of bushes yellow and with red margins. The pink-mite, though seen on these, was not so abundant and active as in other gardens earlier in the season. I infer that, as in Ligri Pukri, this pest is passing off, and that its period of activity is but short, possibly 6 to 8 weeks at most, extending from about the middle of April. On June i8th, I was driven by Mr. Madden all over this large estate. We found yellow foliage due to mite very prevalent, especially so on some young tea raised from Singlo seed. This is a fineya/ of tea with a rich soft foliage that flushes freely and has moderately-sized leaves, but |it would appear to be very liable to this mite. Many of these pale-foliaged bushes were also found to have transparent thickened patches all over the leaves, and these turn into pinkish brown spots. Whether these were caused by the pink or the purple-mite I was unable to determine. The bleached and bronzed bushes looked very unhappy, and unwilling as it were to respond to the showers of rain that had caused other portions of the garden to flush freely. 791. At Makum on the 2ist June, I found a fair percentage of plants (Tingri stock) of a pale yellow colour and with pinkish margins and veins. Only a few of the pink-mite were, however, visible, though the^purple form with three white longitudinal waxy lines was plentiful. This circumstance would seem to point to the two forms being dis- tinct. This estate (in 1895) was only four years old, and no other garden (until quite recently) within a radius of 20 miles. It was, therefore, difficult to understand how the pink-mite had got there so quickly. I also found in another part of the garden that an immense number of bushes had bronzed leaves, as if from red-spider, but that, on the under surface, countless numbers of minute white empty cases were observed, much smaller than the mite mentioned, and conse- quently infinitely smaller than the empty cases of red-spider. As these bushes were not known to have had red-spider, it seemed Tea Pests and Blights. 407 The Pink-mite. probable that they had been attacked by, perhaps, the purple-mite by itself, that is to say, not in association with the pink-mite. If this supposition be correct, the attack may be supposed to have passed off, the more so since rain had been falling for some time. At Tingri visited on the 26th June, I found pink-mite, though evi- dently the attack was passing off. 792. This mite was found quite active in Patalipam,' North Lakhim- pur, July 8th. The leaves of the bushes affected manifested all the peculiarities already detailed as characteristic of it. Mr. Lindsay Alexander had often observed the arrested. growth, pale and bronzed foliage, but had never, until now, seen the pink-mite. He no sooner had it pointed out to him, than he freely admitted it was the undoubted cause of the conditions referred to, and accounted for a heavy loss due to the late flushing of plots so affected. Having had a little more time at my disposal at Patalipam (where I was, so to speak, a prisoner through the rise of the great Subinseri River) than during my forced marches through the tea districts, on the south side, I got out my small field microscope and examined this mite with some care : It was found to have two pairs of legs, each of three joints and with minute hairs at the joints. All the legs are directed forward, lie underneath what may be called the head, so that the rest of the body appears to be dragged and pushed along. The young ones are much smaller than the adults, are oblong, elliptic and only slightly tapered towards the tail, In colour they are white hyaline, the body apparently consisting of three sections and the head. Middle section paler coloured than the other two. As they get older they become more elongated, loose their elliptic shape, and become obovate oblong and pink coloured, with the first and last sections of the body more deeply coloured than the middle or than the head. Surface of the body marked by many transverse folds (10-15 in each section), thus giving the appearance (when seen from above) of a minutely crenated marginal rim. I was unable to discover the mode of re- production, and was much surprised with the fact that I failed to find in Patalipam any of the purple elliptic associate of this mite, which I have already described as having three longitudinal waxy lines down the back. I now believe that the two are distinct species, and that the pink-mite is an undescribed species that in many respects recalls the PHYTOPTIDJE. 793. At Gopesadarhu visited on the I2th July, the pink-mite was found to be still vigorous, but no example of the purple form with white bands was seen. The pest was thought to be disappearing for the present season. 794. Bor Phukuri, visited on the i2th July, showed Mr. W. A. Harry the pink-mite. It was found on good jat Assam which had been PINK-MITE. Tingri. Patalipam Heavy Loss. Description. . Purple-mite not Present. Gopesadarhu. Bor Phukuri. 408 Report of Investigations in Assam Arachnoidea (Phytoptidae). PHYTOPTUS Mljika Jan. Seeonee. Eat the Hairs of the Leaf. Stomata Abnormally Open. EXPO Test irlments. pruned in January. The leaves were pale yellow mottled and covered with the mite, both forms being present. At Mijika Jan visited on the igth July, pink-mite was found very common, especially on the better Assam teas and late pruning. At Seeonee (visited i8th July), I found the pink-mite on good jats Assam indigenous. 795. REMEDY. There is very little that can be said under this heading. By most* planters this is hardly viewed as a blight. The leaves do not fall off, and they even recover colour with the rain. It simply retards the flushing, and in some estates to no very serious extent. There is no doubt, however, that it must weaken the bushes. An observation made by me of the live insect kept for some hours under the microscope, seemed to point to its eating the hairs off the leaf and biting the guard cells of the breathing mouths. Leaves badly blighted seemed to have the stomata abnormally open. Even there- fore, should the flushing be not delayed to the extent to cause anxiety, there can be no advantage in allowing this pest, year after year, to infest the bushes for a month or two at a time. The treatment mentioned above for the purple-mite would be perfectly applicable to this species. I should at all events strongly recommend test experiments to be performed on selected plots, the one being two or three times thoroughly syringed with Adhatoda infusion or kerosine emulsion, and the other left alone. The treated portion should not only flush quicker, but throughout the season manifest greater vigour. Where the pink-mite prevails to an alarming extent, the treatment suggested should be energetically pursued. In other words, I am convinced that, even when present to a small extent, this mite causes a considerable loss, and injures the plants materially. Where present to a large extent, there can be no question as to the imperative necessity of definite steps being taken to secure its eradication. Tea Pests and Blights. 409 Vegetable Parasites of the Tea Plant -Blights. CHAPTER XVII. VEGETABLE PARASITES OF THE TEA PLANT: THE BLIGHTS. 796. It will be recollected that I have imposed a somewhat arbitrary restriction on the words " Pests " and " Blights." The for- mer I have assigned to all the parasitic manifestations of an animal origin, and the latter I now propose to employ as denoting the depre- dations, effected by parasitic plants. There doubtless would remain a third series of ailments that should be designated The Constitutional Diseases of ike Plant. These I have treated as predisposing influ- ences to the ravages of pests and blights. They are very largely brought about by imperfect methods of cultivation, by over-produc- tion, and by age. The Chapters that deal with Weeding and Hoeing, Drainage, Pruning, Plucking and Manuring, have been written with the view to exhibit some of the more readily recognised directions of possible improvement. They by no means exhaust that theme. Had space and time admitted, other Chapters might have been written on The Selection of Site, The Laying out of an Estate, The Nursery, Transplanting and Seed-at-stake, Filling up Vacancies, Top Dressing with Fresh Soil, Trees and Weeds that are Useful or Injurious to the Tea Garden, etc. But the remarks that have already been offered may be accepted as at least justifying the opinion that the time is more than fully arrived when attention should be turned from the Factory to the Garden. The progress made within the past twenty years, in the manufacture of tea, may be said to have given to India and Ceylon their supremacy over China. It rests with the rising genera- tion to preserve that industry by devoting a large share of their atten- tion to improvements in cultivation. If they do not do so, the result may be more disastrous than anything hitherto experienced in tropical agriculture. The enumeration, furnished above, of the animal pests of the tea plant is by no means exhaustive. The brief historic sketches given under each of the more important forms, point con- clusively to two facts, ( a ) that hardly any of these pests were known much before 1870, and ( b ) that the rate of increase both in number of forms and extent of distribution has run parallel with the modern BLIGHTS. Attention Should be Turned from the Factory to the Garden. Important Lessons. 410 Report of Investigations in Assam The Loranthus A Parasite of Seed-Gardens. BLIGHTS. Vegetable Parasites. PARASITES. Con/, with pnra. 83. Weaken the Plants and Injure the Seed. enhancement of acreage production and quality of tea. And the same inferences, it may be added, have to be drawn from a study of the vegetable blights. 797. Unfortunately the time at my disposal, while in Assam, was too limited to permit of an exhaustive enquiry into the subject of the vegetable blights. And to work up even the material collected, might take several years. In presenting the present chapter, therefore, I desire that it should be regarded as but indicating the very extensive field of future enquiry that remains unexplored. While I shall attempt to specialize a few of the more readily recognised Fungal and Algal blights, it is probable that a complete enumeration of all would be very nearly as extensive as that of the pests. The more important vegetable parasites may be said to be two or three fungi found on the leaves ; a fungus and also an alga on the stems ; and one or more species of fungi on the roots. These blights at least demand careful study, since each may be spoken of as quite as dangerous as any of the pests already dealt with. But before taking them up, it may be as well if I dispose of one or two unimportant enemies of tea cultiva- tion, that fall within this Chapter of Blights. 97. (a) Loranthus, *p. 798. Two or three species of these parasites are found on the tea plant mostly in the seed garden. During the time of my visit to Assam they were not in flower, and I was thus unable to determine them specifically. They are, like their near relative, the misteltoe des- tructive parasites that sap the life of the plant. Fortunately they are easily recognized and should instantly be removed. I have seen some seed gardens with every alternate bush or so bearing two or three great clumps of Loranthus. It is a serious mistake to allow these to grow, since they must weaken the plants and injure the seed. The tea plant is peculiarly liable to this class of parasites. In a correspondence regarding tea in Burma (published in The Agricul- tural Ledger No. 27 of 1893) it will be found that a species of Loranthus, there known as chibaung, is spoken of as killing the tea. This no doubt would be the final result with any Loranthus if left to itself. 799. REMEDY. Saw off the branch bearing the Loranthus, and coat the wound at once with the Gondal paint (see page j6j). Tea Pests and Blights. 411 Ferns, Lichens and Mosses. 98. (a) FERNS AND OTHER PLANTS WITHIN THE BUSHES. 800. In Kangra, a species of Euphorbia introduced from America (viz., E. hCterophylla, Z.), has proved troublesome as a weed growing within or around the tea bushes. This I did not meet with in Assam, but in several gardens found two or three species of ferns and occasionally one or two other plants growing within the bushes and doing them considerable injury. Ulu grass is specially destructive to the tea when it gets a footing in a garden. These and such like should, however, be rather viewed as indications of neglect than as pests or blights. While I strongly advocate that, for certain seasons of the year, a coating of herbaceous weeds would not only do no harm, but, on the contrary, much good, there can be no two opinions as to the fact that weeds within the bushes them- selves are most injurious. They rise up and choke the tea and their roots interfere with those of the tea plant. REMEDY. Hand-pick and remove every plant found within the tea bush. 99. ( a ) LICHENS ANJJ MOSSES. 801. Old bushes and those growing in localities with too much shade and imperfect ventilation or defective drainage, become coated with lichens and mosses. The stems are often spoken of as " hide bound," and the lichens are pointed to as the cause. They are in reality the consequence, but not the cause, of the condition complained of. In the majority of cases it will be found that age is the chief cause of the hide bound condition as also of the coating of lichens, mosses and other epiphytic growths. So long as a plant is vigorous and its stem constantly expanding in circumference, lichens will make little headway. Let its activity decline from age. unfavourable surroundings, or disease, and it will immediately harbour lichens and mosses. The chief insect pests that favour the growth of these epi- phytes are the scale-insects. When plant-lice infest the bush, in- significant though they appear, they instantly commence to check its activity. The bush becomes unkempt and untidy. Its leaves are rapidly besprinkled with sand and mud, they turn black through the growth of fungi (soot blight) that feed on the sugary exudations of the insects, or they may be seen to support a botanic garden of beautiful and varied forms of mosses, lichens, liver-worts, fungi and FERNS. Con/, with paras. 23, 95. LICHENS. Con/, with para, 11. Hide Bound. Scale Insects. Soot Blight. Con/, with paras. 37-8. Report of Investigations in Assam Vegetable Parasites of the Tea Plant. PESTALOZZIA GUEPINI. Not Parasites. They are Epiphytes. Con/, with paras. 39, 41. Appeared Ten Years Ago. algae. The bark is seen to split in all directions, to be dry and use- less, and to bear a copious coating of lichens and mosses, or to protect the female scale-insects that nestle beneath and are in fact the cause of the bark being split and torn from the stem. 802. Lichens are not parasites. They attach themselves to plants, stones or other objects in order that they may secure certain advan- tages of exposure to the air and protection from unfavourable cir- cumstances. Thus, for example, the stems of palms growing in open positions will be found lichen-coated on the lee side to the point of greatest rainfall of the locality. Lichens are epiphytes, that is, they live on the air and attach themselves to the surface of plants, without materially abstracting anything from them. 803. REMEDY. To cure the plants so infested, the cause must be discovered and the treatment regulated accordingly. If the land be imperfectly drained, that must be corrected. If the jungle be too near, or the ventilation defective, a clearance must be made by cut- ting openings in the forest to allow of a freer circulation of air. If age be the cause, collar pruning would very possibly renew the garden, and for a time allow of enhanced returns, ultimately a point would be reached, when, in my opinion, nothing further can be done except to uproot and replant. But should the cause be a severe out- break of bark or leaf-louse, the surest and most effectual remedy will be found in firing the plot. This should be accomplished early in Spring, then light prune a fortnight later, and, while pruning, wash or brush the stems and branches with lime, to remove all the charred lichens, mosses, and other adhering matter. (Con/, with the foot- note, p. 6.) LXX.Leaf Parasites or Blights. IOO. (c) Pestalozzia Guepini, Desma*. GREY BLIGHT : by some planters called DRY ROT. References. Desmazieres in Ann. Sc. Nat. Ser. II. p. 183 ; Diseases of Plants by Dr. Karl Freiherr von Tubeuf, (translated by Dr. W. G. Smith), p. 494- (Reg. No. 134; botanical specimens Nos. 11903, 11930, 11933, 11934, 11 93$> U94l> i*94 8 > 11967 and 11969.) 804. HISTORY. So far as I can discover, this blight has appeared within the past ten years or so at most, and was first seen in the Dibru- garh District. It then crossed the river to the north bank gardens and extended right down to Tezpur ; it also recrossed to the south at Tea Pests and Blights. 413 Grey Blight. Nowgong. So far as Sibsagar District is concerned, I only met with it in one garden and on a few bushes. Since the date of my explorations I am led to believe, however, it has appeared very bad in one or two gardens in Jorhat. Although met with on all jats of tea it seems to show a preference for the China plant and low class hybrids. 805. In Europe it is a well-known blight on Camellia, Citrus, Magnolia, Rhododendron, etc., but, until discovered by me on the tea plant, was not known to occur in India. Recently I received a sample of tea affected with it from Cachar, and Mr. E. E. Green has kindly furnished tea leaves infested with it, so that this blight occurs in Ceylon, as well as in Assam and Cachar. It is, therefore, highly probable that it exists in all the other tea districts of India, but I may add it was not found by me in Kangra. 806. DESCRIPTION. For the purpose of the present report it will suffice if I furnish a popular description of this very dangerous blight. At first it appears as minute brownish-grey spots on the upper surface of the leaves. These increase in number and coalesce into large patches, which thus come to have an undulating outline. The indi- vidual patches will be seen to manifest a slightly thickened rim of a pale greenish brown colour, and near this may occasionally be ob- served a series of small black warts or perithecia. As the rim widens, zone upon zone of these perithecia are formed until the surface , of a large patch becomes methodically spotted with black, over the otherwise smooth and ultimately whitish grey. But the perithecia are, however, only occasionally present, the majority of the leaves will be seen to be simply covered with numerous variously shaped brown and grey patches some not larger than the head of a pin, others an inch or more in diameter. On the under surface of the leaf, a corresponding portion, to that invaded by the grey patch of the upper surface, will be seen to be discoloured, but to manifest no external formations. It very often happens that these brown and grey patches commence near the base of the leaf, but they may ap- pear on the apex or on the margin, or two or three may form at once and extend until they unite, when the entire leaf may assume a dirt whitish grey colour. Under the lens it will be seen that the grey cc proceeds from the epidermis being raised up from the rest of the leaf tissue, like the loose cuticle over a blister. There is no blister or GREY BLIGHT. Found also In Ceylon. Minute Spots. Perithecia. Under Surface* Point of Origin. Epidermis Raised. Report of Investigations in Assam Vegetable Parasites of the Tea Plant. swelling however, the leaf is of its normal thickness, and, far from being blistered, it will be found that beneath the separable epidermis the tissue of the leaf has been dried up in a peculiar manner, so that it crumbles to pieces and readily separates from the veins on being pressed between the fingers. 807. The fungus proper may be said to reside within the leaf ; it absorbs the sap and completely transforms the tissue. Naturally the leaf is thereby killed. The black warts (perithecia) may often be found below the epidermis, even when not visible above. Under the micros- cope these are seen to be comprised of a number of curiously formed bodies crowded together, each attached by a short stalk. These are the sporules, and, when examined more carefully, will be found to consist of a transparent pedicle, supporting a central black body, (composed of three rather square cells) which bears on its apex hyaline cilia. These sporules may in fact be spoken of as consisting of three dark and two hyaline cells, the terminal hyaline cell having a plume of divergent filaments. The sporules (conidia), or as they were at one time called sporidia, are of course very minute and look on the surface of the leaf like a fine black powder, the particles of which are blown in the wind and communicate the blight all over the tea garden. A peculiarity of this fungus, as met with on different host-plants, may be here mentioned, viz., that it so completely changes its external form that without the microscope it is unrecognisable. 808. It may also be noticed that the leaves of the tea bush are often sewn together as it were. A diseased one above drops into contact with a healthy leaf below, and where they touch they become cemented by a curious tuft of fungal filaments. I have not as yet been able to establish that this cementing of the leaves is directly connected with grey-blight, since this peculiarity is not universally present ; nevertheless it is of so frequent occurrence as to justify the circumstance being mentioned. Many fungi are known to dispense with the production of spores (seeds) and to reproduce themselves in- definitely by mycelia or thread-like filaments. From the circumstance that only a few leaves may be found to bear the perithecia with their sporules, it might be inferred that this blight, by means of the filamentous union of the leaves, was extending its destruction from leaf to leaf and plant to plant, without the production of sporules. I have reason to suspect that diseased leaves borne in the wind adhere Tea Pests and Blights. Fungi on the Leaves Grey Blight. to objects with which they come in contact, and thus communicate the blight. But, on the other hand, grey-blight is often associated with thread-blight a disease that it will be found, from the account given below, most undoubtedly is communicated by affected parts becoming attached to healthy structures. 809. DEPREDATIONS. This is one of the most destructive and most dangerous of the parasitic fungi to which the tea plant is liable. It commences for the most part on one side of a bush, very often on the same sides of all the bushes over an affected plot a circum- stance that may be taken as indicative of the germs having been wind-conveyed. It then may work round the circumference of the bush, killing a section of perhaps a foot or more in breadth, or it may gradually ascend and ultimately pass through and over the bush, until every leaf and shoot is killed. On the spots appearing, the leaves gradually become darker coloured, so that the affected bushes may be recognized from a distance ; indeed the whole garden may appear to turn brown and grey. As the disease advances, the leaves fall off and collapse on the top of each other, and become fixed within the twigs of the affected part, giving it a very diseased appearance. The blight commences, first of all, on the surface of the bush, so that the dead leaves lie on the top, as the destruction extends down, round or through the bush. But it is a striking feature that it is confined, as it were, to one part of the bush (that is to say, the whole bush is not simultaneously invaded), and it advances but slowly or may leave that bush and pass to another without doing more than killing a space of a foot or two in diameter, Moreover, the blight does not attack every bush at once, but one or two here and a nest of others there ; and as the season advances it spreads more rapidly until large plots may be completely destroyed. Unfortunately I only made acquaintance with this blight on the 2ist of June, and in less than a month's time had to leave the province, so that I neither saw the early nor the late stages of the disease. I had no opportunity of seeing whether the invaded bushes or por- tions of them were killed outright, but I was assured that this was so, and that to this disease has to be attributed much of the un- shapely condition of many plants, whole sections of them having been destroyed by this blight. It is by no means an usual occur- rence to find bushes with holes eaten out of them, as it were, on Conf. with paras. 839 SO. Wind- Conveyed. Turning Brown and Grey. Dead Leaves Lie on Top. Often Confined to One Part. Is Scattered Over the Estate. Killed Outright. Holes Eaten out of the Bushes. 4 i6 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. Sometimes called Blister Blight. one side, or with the circumference reduced artificially, and, I was assured, such occurrences were the work of grey-blight. It can well be understood, therefore, that where this blight has appeared to any serious extent, it gives greater cause for anxiety than almost any other malady to which the unfortunate tea plant is liable. 810. In Dibrugarh I found that many planters called this "blister blight," and that they were at the same time unacquainted with the " blister blight" of Sibsagar District. It would thus appear that, not only has that term been incorrectly applied to green- fly (p. joj), but that two widely different fungi have come to bear the popular name of " blister blight." To remove this ambiguity I have given the name grey-blight to the present species, and restricted the term blister blight to the form described below. This assignment seemed all the more natural, since in the present malady the tissue of the leaf is in no way thickened nor rendered moist. In fact it shrinks and dries up, and as the disease advances, the only peculiarity that could justify the term blister would be the separation of the almost white membraneous epidermis to allow of the escape of the sporules. REMEDY. During my examination of this blight, I suggested to one or two planters the desirability of trying the effect of burning the bushes. It was of course very late in the season to attempt firing as a remedy, since doubtless many bushes would be killed by the severity of the treatment. But the serious nature of the blight rendered it imperative that immediate steps should be taken. To lop off the shoots affected or to collar prune the bushes, would expose the surrounding ones to the risk of being sprinkled with the conidia. The results so far of the experiments with firing have, however, been significant, and I think may be here quoted, with the suppression of the names of the gardens concerned. 811. Mr. H. wrote: " I see you have described the blight most prevalent on this garden as the " grey blight," it is still increasing to a most alarming extent and causing me great anxiety. Neither of the remedies you suggested have done much good in the way of either curing or checking it." " If you remember, we burnt two or three bushes near the bungalow here, and after you left I treated some hundreds in the same way, the result being that in every case they died down to the ground, there being no sign of growth of any kind for six weeks or so, Separate Epidermis. Burning. Pruning. Extending to an Alarming Extent. Firing in June. Tea Pests and Blights. Fungi on the Leaves Grey Blight. after which shoots commenced to come away from the roots. I need hardly say that none of these bushes will have sufficient growth on them to give any leaf again this year, and lately J have noticed that a large percentage of them are affected with the same blight again" " I also tried (as you suggested) cutting out the branches of some thousands of plants that showed the blight in small patches, but this treatment has apparently not had any effect in checking the disease. The branches all round those which were taken out are now in the same condition as those which were removed. Roughly speaking 1 should say some 20 per cent, of the garden is now suffering from this blight." 812. I have rendered two passages in the above report in italics in order to draw special attention to them. It does not follow that, because the shoots that sprang up after firing, again showed the blight, that therefore fire could not be regarded as a remedy. On the contrary, 20 per cent, of the garden being affected, the atmosphere might be viewed as permeated with the germs (sporules), and the young shoots might be specially addicted to receive the blight. But let me add that, in my opinion, it is of no consequence if bushes do not flush for some time after being fired. This is a blight of so alarm- ing a nature that a loss to that extent must be faced, rather than allow the blight full scope of a wider distribution. What would be the result were the disease to attack, not 20 percent., but the entire estate ? And I believe that is not an improbable contingency. The very severest measures should instantly be taken to stamp out this blight wherever it appears. If one system of treatment does not succeed, another must be tried. 813. The second report received by me was as follows : Mr. L A. wrote, " I tried burning as you recommended, and have concluded that this can only be done safely when the sap is down. Some of the bushes have not recovered, most are weak, and may require collar pruning, but worst of all the blight is showing on the young leaves." 814. It is probable that I recommended firing to be tried in a dozen gardens at least, but have only received reports of the results obtained from two. Still, however, these may be admitted as suffi- ciently unfavourable to justify the.statement that direct experiment is required before firing can now be urged as a remedial firing every affected bush, in the early 27 That months of an outbreak, GREY BLIGHT. Some 20 per cent, of Garden Suffering. What Percentage were Cured by Fire. Blight Returned. Fire tn Early Part of Season. Report of Investigations in Assam Vegetable Parasites of the Tea Plant. PESTALOZZIA GUEPINI. Scientific Report Promised. Fungicides. Bouillie Bordelaise and Sulphur. Advisable to Treat in Early Stage would check the spread of the disease, there can be no doubt, since every leaf so destroyed might have extended the malady. Burning in Spring would not injure the bushes, and it would certainly check the spread of the disease, but it is probable we shall not be in a position to lay down definite lines of treatment until the full life history of the fungus has been worked out. 815. I am told by Mr. W, T.Thiselton Dyer, C.M.G.,C.!.E., Director of the Royal Gardens, Kew, by letter of the 24th January 1896 that Mr. Masses has been engaged on the study of this blight, and that his report may be expected at an early date. That report will no doubt prove of the greatest value, in affording a key to the weakest stage in the life of the fungus. 8 1 6. Meantime, it may be recommended that the usual fungicides may be tried. Perhaps the most hopeful would be the Bouillie Bordelaise preparation of quick lime and sulphate of copper. The following might suffice for an acre : 458) sulphate of copper, 22^Eb quick lime, 220 gallons of water. The sulphate of copper should be dissolved by suspending it in a coarse cloth or basket in water contained in a wooden vessel. Hot water dissolves the sulphate more quickly, but in that case it must be allowed to be quite cold before being utilized. The quick- lime should be slaked in a separate wooden tank or tub, and then stirred into a fine gruel with water gradually added. This should then be passed through a sieve into the solution of copper, the mix- ture being well stirred the while, and the balance of water added to the total quantity mentioned. With this the bushes should be thoroughly syringed. 817. In the treatment of fungi a solution of lime, common salt and sulphur has also been found useful, in the proportion of, say, 8Ib lime, 3ft salt, and 4lb sulphur, for every 12 gallons of water. Mix one-fourth of the water, one-fourth of the lime, and all the sul- phur, boil for an hour and half ; the salt with the rest of lime to be slaked with hot water, then added to the above, boil again for half an hour longer. Add the remainder of the water, and use when cold. I have suggested the above treatment more because of the urgency of the case, than from any knowledge of the probable result. Grey-blight is a malady that every effort should be made to stamp out. Like most other blights it can be treated when present to a small Tea Pests and Blights. 419 Fungi on the Leaves Grey Blight. extent, but a very different state of affairs may be experienced when once allowed to be fully and freely established. 101. (a) Exobasidium vexans, Masses, SP. nov.* BLISTER BLIGHT, WHITE-BLISTER. References.-/^/, Journ. Agri.-Hort. Soc. lnd. t Vol. /., Proc. ilth June 1868, xli vi IV. n.s., 1873, p. 126; Baildon, Tea it Assam, p. 45. (Reg. No. too : tube Nos. 85, 108, 155, 208, ato, 257, 362 and 396 botanical specimens Nos. 10421, 11142 and //95p.) 8 1 8. HISTORY. The earliest mention of this blight occurs in the Journal of the A gri. -Horticultural Society of India for 1868, wher< it will be seen the late Mr. 8. E. Peal furnished samples, and ex pressed the opinion that it was most probably caused by a fungus He there stated that he had first known it ten years before, so that if anything, this may be said to be one of the earliest, as it is to this day, one of the least understood maladies of the tea plant. The Secretary, Agri.-Horticultural Society, in submitting Mr. Peal'8 samples remarked that, " the disease appeared identical with that which caused so much damage last year in certain gardens in Cachar but, unlike Mr. Peal's experience, it attacked the China plants principally." At the period in question it was mosquito that " causec so much damage in Cachar." Mr. Baildon is the only author oi a book on tea (published 1877) who makes mention of blister- blight. His remarks may be here quoted in full : " I think this is worse than mosquito blight. I do not know whether it has been really ascertained what causes " Blister Blight." A leaf gets a small speck upon it at first, which, as it enlarges, assumes the appearance of a blister, and ruins the leaf entirely. An old belief was, that when a drop of rain or dew remained on a leaf, the sun coming out acted as a magnifying glass upon it, and burnt a hole. Others believed the blight to be caused by a bug. I think this most probable." The sun theory of blister is constantly brought * While engaged on the preparation of this report I furnished the Director of the Royal Gardens, Kew, (July 2ist, 1897) with a complete set of my collections of fungi, found on the tea plant in Assam. In the report which I have had the pleasure to receive from Mr. W. T. Thiselton Dyer, (dated November, ijth), Mr. George Massee furnishes his scientific deter- minations of two species, via. Blister Blight and Thread Blight (for the latter see page 433). The present report being now in final page proof I am only able to insert the scientific names furnished and this brief ac- knowledgment. Mr. Massee's detailed account of these fungi and of Pestalozzia Guepini, which I understand will appear very shortly in the Kew Bulletin, will be awaited with much interest. 27 A BLISTER LIGHT. Con/, with paras. 39, 4%. Mistaken Identification. Worse than Mosquito. Sun Theory. 420 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. EXOBASI. DIUM VEXANS. Distribution, as to be Called an Epidemic. Attacks Young Leaf. Attacks also the Green Stem. Pale Green Spot. Below a White Blister. Assam Indigenous Jats. up to account, not only for the present disease, but for the minute blisterings of the mites. I have never seen a case of sun blistering, and suspect there may be some mistake. If it does occur, excessive evaporation, and not the magnifying glass theory, would have to be accepted as the explanation. (Con/, with para. 119-) 819. By way of concluding this review of the facts that have a bear- ing on the history and distribution of this malady, I would here add that I have failed to find evidence that it has ever visited Cachar, Darjeeling, the Duars, in fact any other part of the tea area than Assam. And even in Assam it is very erratic. It is most prevalent in Sibsagar, is perhaps unknown in Dibrugarh, occurs in North Lakhimpur, but does not appear to have reached Biswanath, Tezpur nor Nowgong. 820. DESCRIPTION. The following is Mr. Peal's account of this blight. I make no apology for giving it in full since it practically tells all that we know to the present day, and shows that the chief peculiarities of the blight have not been modified in any essential, during the past forty years or so : " I take the liberty of enclosing some leaves of tea that have been attacked by a kind of white-blister. This disease is so common about here just now, that it might be called an epidemic. It attacks young leaf, and is injurious, inasmuch as it stops the bush to a great extent in giving leaf. I have noticed it, sparingly, for some years, and have not been able to ascertain the cause, but I appre- hend it is a fungus ' smut or rust,' and not caused by any insect. " It is chiefly confined to the leaves, but it is also seen occasion- ally on the green part of a stem, or the green husk of the seed. When fresh, it presents the appearance of a pale green spot (usually pitted) on the upper surface of the leaf, and on the lower surface is seen as a raised white blister-like spot with a floury or mealy texture, usually circular. The diseased portion eventually turns a brownish colour, and the leaf, wholly or in part, dies. " So far as it seems peculiar to tea, I have searched for it in vain on other plants, as it seems to attack it under all circumstances alike, equally so in the open as under shade, in jungle or in clear and highly-cultivated patches : this, at least, is my experience so far; varieties of Tea, including the 'China,' seem to suffer less than those more nearly allied to Assam. I have reason to believe that this disease shows chiefly after long heavy rain. I had Tea Pests and Blights. 421 Fungi on the Leaves -Blister Blight. heard so before, and this year would seem to confirm the supposi- tion, the rainfall during April having been very heavy. A patch of Tea near here, of 20 acres or more, has been so generally attacked by this disease, that I have ceased to pluck it, and the garden in places presents quite a withered appearance. Other gardens around are also suffering, the disease being, if anything, on the increase. I have heard that, about ten years ago, the tea suffered severely from this same blight, but that the following season it all but dis- appeared. It will certainly have a marked effect on all the estimates of ' crop,' as it seems to check leaf coming out." " The Secretary remarked that, " the disease appeared identical with that which caused so much damage last year in certain gardens in Cachar; but, unlike Mr. Peal's experience, it attacked the China plants principally, while the Hybrid suffered but partially, and the indigenous was scarcely affected at all." 821. By way of comparison with Mr. Peal's description it may be useful, if I record here a description of the blight as met with by me. It first appears as a minute pale brown or pinkish spot on the upper surface of the leaf. This enlarges in size, mostly in a per- fectly circular manner, gradually becomes depressed into a pit about the size to admit the tip of the little finger, is smooth, polished and glistening, as if coated with honey-dew. On the under side of the leaf there is a corresponding swelling which is pure white, woolly and soft, but quite dry. 822. The appearance of the structure recalls forcibly many of the larger blister-galls, except that these do not form pits above, corre- sponding to the wart-like swellings below. But blister-blight is in no .way of insect origin, but, on the contrary, is caused by a truly parasitic fungus that belongs to a group of forms sometimes spoken of as the blister fungi. A tea planter of considerable experience, in Dibrugarh, assured me that he knew blister-blight perfectly, though there was none of it at the date of my visit that he could show. He further said that, as a remedial measure, he sent out the coolies to collect all affected parts (leaves, buds, etc.), and that on being brought into the factory these were burned. The pluckings were placed in baskets and covered over to prevent the escape of the very minute insects which, he assured me, caused the blight. I pre- sume that some such experience may have led to the association of BLISTER BLIGHT. Plucking Discontinued. Appears First as a Minute Spot. Becomes Depressed and Glistening Above. Swollen, White and Woolly Below. Assured by a Planter was Caused by an Insect. 422 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. 'SIS? 1 ' Large Formed by Coalescence. They Change Colour, Become Brown then Black. Lasts for two Months. Is Erratic In Its Recurrence. Appears First on Unpruned Spreads Rapidly. Climatic Influence. the term blister-blight as synonymous with green-fly. But to resume the description of the blight: as it advances, numerous blisters appear on the same leaf and even coalesce into large patches. They also occur on the young shoots, and cause large hypertrophies of the axis. In time the blisters change colour, become brown, and ulti- mately black. The shoots next wither, and the entire plot of tea may then look as if a blast from a furnace had passed over it and killed every shoot and leaf. 823. This is truly one of the most alarming of maladies and, but for two considerations, would render tea planting impossible : ist. It lasts for at most two or three months, then disappears, and the bushes rapidly recover. 2nd. It is most erratic in its occurrence and recurrence ; that is to say, it may be very severe for a year or two, and disappear suddenly and unexpectedly for the next half dozen seasons, only to come back again when least expected. But it invariably manifests one peculiarity, which as yet it has shown little tendency to alter, viz., a remarkable preference for unpruned Assam indigenous tea. In fact, it may be said that if a garden possesses no Assam tea flushing in February and March, it will escape this blight, unless it chances to be in close proximity to a garden where these conditions exist, in which case, as the season advances, it may become contami- nated. Once introduced, the malady extends to the later flushing teas, but appears never to attack China, nor low class hybrid bushes. 824. DEPREDATIONS. As just stated, this very remarkable blight attacks chiefly the higher jat indigenous teas, and is confined to un- pruned tea in the first instance. As remarked by Mr. Peal, it seems, however, highly probable that certain climatic conditions are essential to its becoming established on tea. This is no uncommon circum- stance in the development of fungi. The germs exist year after year, but to so limited an extent as to escape observation, and only assume gigantic proportions on the recurrence of favourable conditions. It is essentially a disease of Spring, and lasts for about two months from the date of its first appearance, although it would seem to occa- sionally recur at other seasons, and in some few instances has betn Tea Pests and Blights. 423 Fungi on the Leaves White-blister. reported to exist in a mild form throughout the year. In a garden visited by me on the 7th April, there was a plot of high class tea that had been collar pruned in December 1893. It sprouted in Febru- ary 1894, was not pruned the following Autumn, but was once or twice plucked in the Spring of 1895. Blister-blight, however, appeared, and, at the date of my visit, every leaf and shoot was liter- ally covered with the disease. It appeared on the 2oth March, near the jungle and in a shady part of the plot. It would thus seem that young fresh shoots, on unpruned tea in early Spring, are peculiarly liable to this disease. But in the garden to which I allude it had extended from the unpruned plot, very nearly all over the estate attacking all the leaves of the Assam jafs as they appeared, but avoided arbitrarily the China and hybrid plants. The manager was of opinion that blister-blight was each year getting more severe certainly nothing could have been more disastrous than the state o affairs seen by me. Within a radius of perhaps 20 miles or so every alternate garden was, at the time I speak of, found to hav blister-blight more or less severely and, in each instance, it ha appeared upon unpruned tea, near the jungles or under the shade of avenue trees. The extracts from my diary, which will be found below, afford in several directions suggestive observations. Bu it may be here remarked that the point of origin and radius o distribution around each centre was most significant. Extending awa) from the unpruned plot of each garden, the plants were foun< black, where the disease had first appeared, white with large blister: in the intermediate zone, and sprinkled here and there with glistening spots, on the limits of distribution. There could be no room fo doubt as to the point of origin, having been on the early flushinj unpruned or lightly pruned tea, and the distribution or rathe radiation toward the later flushing bushes. In the following season (1896) a mild attack appeared, am in 1897, when I wrote to a dozen gardens or so, asking for fresh mate rial to enable me to examine the fungus in connection with this report 1 got the same answer all over the province that the disease had entirely disappeared. But I am led to understand that this is by no means an unusual circumstance, and that it is a well-known fact that blister-blight suddenly appears, and as suddenly disappears in a very unaccountable manner. ;HT. ippears to riginate in Proximity to Jungle. Con/, with paras. 826, Getting ire Severe. More Favours the Blights. Radiation from Point of Origin. Dis- appearance. 424 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. 825. REMEDY. Most planters have assured me that, if the bushes are promptly and severely plucked, on the blight appearing, it can be got under hand and checked. Mr. Alexander, whose opinions will be found below, in the passages extracted from my diary, found lime an effectual cure. There would seem every reason to suppose that this ftyigus could be materially checked, if not eradi- cated with the fungicide treatment recommended for grey-blight. Although the active portion of the blight appears on the under side of the leaves, there would be little difficulty in reaching the patches, owing to the affected leaves becoming contored with the blisters so as to bring the under surface into full view. I would, therefore, recommend that, on the first appearance of this blight, the bushes should be freely syringed, and for this purpose it would be desirable to be fully prepared, in all gardens where unpruned tea exists. A stock both of the fungicide fluid, ready for use, and a liberal provision of syringes should be at hand. It is probable that moping the affected flushing shoots with a large brush made of flax or sunn-hemp, might be found fully as expeditious as syringing. If not, it seems probable that syringes on the native pattern might be made of bamboo at a mere nominal cost. There is no doubt that in the treatment of all pests and blights by insecticide and fungi- cide fluids success depends upon promptitude. If allowed to invade a large area of the garden, such treatment, in my opinion, becomes quite impracticable. Diary Notes on Blister Blight, 826. On the 6th April, I had a conversation with Mr. B., of , in the Sibsagar District, on the subject of blister blight. As it may be found of interest, it is given in the form of question and answer : 1. On what class of soils does the blister-blight appear ? Damp low- lying soil, adjoining the jungle. 2. When does it appear ? March. 3. When disappear ? It varies, but usually it exists only two months, though in some cases it may be seen throughout the year. 4. Have you any idea of its causation ? No. It appears on strong and weak bushes alike. 5. Does it run a regular course on each plant? Yes. It appears as glistening"pale-coloured depressions on the upper surface of the leaf, which become white and woolly-looking below. These invade the young leaves and twigs. After the plant has been thus attacked, the diseased portions wither and turn black, and the blight disappears from the bush, but leaves it as if it had been burned and the flushing shoots charred. 6. Do the bushes go through these stages simultaneously? No, one after the other as it extends. For example, bushes in the black stage may Tea Pests and Blights. 425 Fungi on the Leaves Blister Blight. now be seen on the circumference of the garden, approaching the forest' while pretty nearly all over the garden others with blister blotches may be found, the further from the original source the fewer in number. 7. Do you know any cure ? No. 8. Do the bushes recover ? Yes, and then appear as if they had been severely plucked. On the jth April, I had a conversation with Mr. A., of , on the subject of blister-blight. He informed me tHat, in his opinion, the blight would not occur were all collar pruned plants again pruned in the ordinary way. He remarked that the disease first appears on the portions of the garden not pruned. For example, a plot of land, 12 acres, The shoots ions was appeared collar pruned in November-December 1893. February 1894, and were left alone till March 1895, when it was plucked twice. The plot was thus in leaf right on from that date, whereas the rest of the garden around had been pruned until only the old leaves were left on the bushes. In other words, the 12 acres were flushing before the other portions showed any signs of activity. The blight appeared about the 2Oth March, after the plot had been once plucked, and was first noticed near the jungle in shady positions. It then spread over the rest of the unpruned, and ultimately the flushings of the pruned tea. It is now met with all over the garden, more prevalent near shade as, for example, alongside of the avenues. It would thus appear a fair inference that the unpruned bushes having young fresh vigorous leaves in March are in a fit state to be attacked by the blight. The rest of the garden having at that season only old hard leaves afforded no opportunity for the pest. 1 his idea is con- firmed by the fact that even now only the young vigorous leaves are attacked, not the old hard ones. It is certainly very significant that the blight, as seen by me, was in a radius around the two plots of unpruned tea, and diminished on advancing away from these centres until, at a certain distance, it was hardly to be seen anywhere. Mr. A. is of opinion that blister-blight is getting more serious every year. The bushes are for the time being destroyed. When they turn black the disease stops, it has run its course, and in two months' time the plants recover. It disappears, say, in May, and does not return till next spring, but during these months it may stop the yield entirely of the por- tion or portions affected. Speaking of blister-blight Mr. 8. E. Peal feth April 1895), said that he had never seen it except near shade and in the vicinity of forest, he first observed it at Sonari and Jaipur near forest and always under shade. At a garden in Sibsagar (visited April nth), here and there. found blister-blight On April i ith, visited a garden that had a plot of tea that had only been trimmed last autumn, not pruned like the rest of the estate, and which accordingly sprang into early flush : blister-blight had appeared on the unpruned bushes very badly. During the inspection of a garden on the way to Amguri (April 1 8th and igth), the Superintendent (Mr. G.) informed me that blister-blight BLISTER BLIGHT. Appeared on Unpruned Tea. Appeared near the Jungle and under Shade. Attacks Young Vigorous Shoots. Bushes for Time being are Destroyed. Appears near the Jungle and always Under Shade. 426 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. EXOBASIDI- UM VEXANS. Jorhat. Dibrugarh. *&$? Leaves Collected Dally. Plucking Recom- mended. Blister Blight Reported to be Caused by an Insect. first appeared on unpruned tea about the first week in March. It has now spread to all kinds Of tea, and is practically all over the estate. This is a good garden with a rich red-clay soil : plants very healthy and large except that mosquito and blister-blight are very bad. It is an open and exposed with little or no shade. April 24th, visited a garden in Jorhat Division, blister-blight rare. At a garden visited by me on the 25th April in the Jorhat Division, I found no blister-blight. At Jorhat on the 26th April, blister-blight was only once or twice seen. At Badulipar (May 2nd), I found no blister-blight though unpruned tea existed. At Dibrugarh on the I5th June, Mr. M. informed me that blister- blight was caused by an insect. He holds that the pustule-like white masses on the back are galls containing eggs. He has sometimes col- lected as much as 60 maunds a day of the infected leaves. The women used to throw these into their collecting baskets, that were carefully covered over with a cloth. When brought to the factory to be destroyed, he had seen very mute insects, of a grey coloured and ^th inch in size, rise in thousands from the baskets. He holds that the infected bushes should be plucked as hard as possible and the pluckings burned. He also remarked that the galls extend from the leaves to the twigs in gradually expanding patches until the entire young shoots are invaded and killed. I pointed out that galls were, as he stated, caused by eggs being deposited by an insect, and that, unless the insect returned and de- posited more eggs, the galls could hardly, as he affirmed, extend from one part to another, although they might swell in size. He informed me that he had seen patches of the garden with every twig black, killed back to last prunings. This terrible malady, he re- marked, is checked, if not extirpated, if the leaves are persistently plucked, and the pluckings burned. He is certain that throwing the cuttings into the jungle is dangerous, because, as he explained, the insects escape and fly to the tea to infect other bushes. Mr. M. was unable, however, to show me a leaf with the blister-blight on it, so that I was not able to determine whether or not his so-called blister-blight was the pest that I had studied in Sibsagar under that name. It has disappeared now (June i8th) from all the gardens of Sibsagar and Dibrugarh Districts. It appears, as a rule, about March, and by June it disappears. But my experience of it differs greatly from that of Mr. M. It attacks the twigs doubtless, but its expansion from one spot to another and the enlargement of the spots is inexplicable as it seems to me on the theory of its being a gall as usually accepted. Had winged insects been found in association. I should have seen them, or at least the dozens of other planters with whom I had con- versed would have seen them. I repeatedly enquired if any insects had been observed hovering over the bushes, but got the answer invariably that no insect had been seen. I was thus prepared to be incredulous of Mr. M.'s observations. In consequence I informed Mr. M. that his blister-blight and that found in Sibsagar, and of which I had seen many hundreds of acres badly infected were two entirely different things. But I have no sort of opinion what the Dibrugarh blister-blight could be unless Tea Pests and Blights. 427 Fungi on the Leaves or White-blister. Mr. M. made the mistake that I find inl the Museum Notes regarding blister-blight as another name for green-fly. At Panitola, visited on the i6th June, no blister -blight was seen. I mentioned the circumstance recorded on the previous day, and said I was particularly anxious to see the blister-blight of this district. I was shown grey-blight and told that generally bore the name of blister-blight. On the 27th June at a garden in the Dibrugarh District, I was told that blister-blight had been bad on unpruned tea, but I saw none as it was over. During a very interesting conversation with Mr. Lindsay Alexander at Patalipam (North Lakhirr.pur), July 6th, 1895, I learned that, in his opi- nion, blister-blight usually appears on unpruned or very lightly pruned tea. It generally is first seen about the beginning of April, reaches its height in three weeks and disappears within six. The withered leaves with black patches, caused by the blister, if not removed, remain on the bush till August, and the shoots that had been invaded may be seen even longer than that, as black dried up twigs. Mr. Alexander informed me that he first saw the disease in 1875, in the seed gardens at Bazaloni (one of the finest of indigenous Assam teas), but it never spread, nor did serious damage for many years. He further remarked that in Patalipam it may have existed in 1890 or before that date, but on his taking charge it appeared in April of 1891 and on tea near the N.-E. jungles. Tea considerably to N.-W. and W. has not ns yet been attacked. It spread to S. and S.-W., proceeding W. in the first instance, but it never crossed to the Western jungles. The garden extends N. and S., the river being S. The winds during day blow from the river up the garden, at night the reverse. The ice-cold water of the river, Mr. Alexander thought, might exercise a local influence in checking the spread of the disease, consequently, if diffused by the wind, it most probably was distributed at night. In December 1894 (and this was the first time he had seen it so late in the year), it appeared near the river, right on the bank, and affected only two or three plants. But in the following spring it re-appeared also near the river to the westward and spread N. W. In addition to this it appeared spontaneously in other spots but always near the jungles. Mr. Alexander regards blister as the most deadly of all blights, for the time it lasts, since it kills everything. Lime water had been found of value. It blackens the white under patch of the pustules, and appears to kill the disease. But if taken in time, plucking the affected parts is of great value in checking diffusion. At Dirpai, plucking had been perfectly effectual, every leaf and twig which showed blister was instantly plucked off during April, with the result that the disease disappeared for good from that garden. At first Mr. Lindsay Alexander was disposed to tHnk blister came from a very common Ipomaea that shows large yellow blotches very much like blister. He had arrived at the opinion, however, that this was not the case. He procured a few leaves for me and I confirmed his conclusion The Ipomaea was attacked by an unmistakable fungus, absolutely uncon> nected with blister. I mention this circumstance, however, since several planters have sent me leaves of that very plant, showing that the mistake was one that might be readily enough made. Mr. Alexander failed to discover the disease in the jungles, and two or three days were spent by me in the same fruitless search. The fact of its appearing late in the year in BLISTER BLIGHT. Panitola. Patalipam. Appeared in December. Most Deadly of all Blights. Plucking Useful. 428 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. a spot where, in the following spring, it reappeared with great severity is most instructive, and shows that the disease is one that cannot be trifled with. At Gopesadarhu, visited on the I2th July, blister-blight was unknown. At Salonah, visited ijth July, Mr. Henderson informed me that blister-blight is not known in that district. Tezpur, the planters of this district are unfamiliar with blister-blight. Brown Blights on the Leaves. 827. Under the above name I collected three or four species of widely different epiphyllous fungi that all agree in one point, namely, that they cause portions of the leaf to turn brown. These brown patches ultimately decompose into perforations, or large portions of the leaf crumble away or subsequently become mouldy and rotten from being attacked by saprophytic fungi. Though one or two of these fungi are fairly prevalent and even cause considerable injury to tea, they can hardly be classed as definite blights. I should not at all events, in the imperfect state of my information have alluded to them, had it not been for two fairly important considerations : It seemed desirable that I should in theyfrj/ place distinguish these from grey- blight and blister-blight. In the second place, the history of parasitic fungi is replete with instances of certain forms having remained in the position of curiosities for an indefinite time, and to have then suddenly assumed alarming proportions and become dangerous blights. It is as well, therefore, that whether, at present compara- tively harmless and only rarely met with, or destructive and prevalent, every parasitic fungus, found on tea, should be made known and as far as possible eradicated. Since, however, I am unable to assign to all the blights of this group, their scientific names, I shall describe them in general or popular terms. * M 102. (c) BROWN SPOTS WITH A PALE-COLOURED MEMBRANEOUS EXPANDING BORDER. (Botanical Specimen Register No. 11909.) 828. This blight is met with here and there all over the valley of Assam, but curiously enough is more especially prevalent on the plants in the seed garden than elsewhere. In the condition I wish here to specialise there is no pitting of the upper surface, no soft hairy swel- Tea Pests and Blights. 429 Brown Blights on the Leaves. ling below, as in blister-blight. The upper surface does not become greyish-white, through the separation of the epidermis, as in grey- blight. The spots are formed, as a rule, not more than a quarter of an inch in diameter, but occasionally twice that size. These are dark coloured, dry, and never enlarged in size. They are from the earliest stage surrounded by a pale border or rim that at once fixes their shape and size. The most striking feature of this malady is that the pale borders widen and those of adjacent spots may even coalesce, without there being any union of the central brown spots themselves. The advancing and expanding rim is in fact the seat of the active disease. In time these pale bands turn straw coloured, become dried up and almost membraneous. On reaching the margin of the leaf, they cause a constriction, so that the affected portion turns over and shrivels up. The original central spots now appear like islands within the expansion of chestnut-coloured and membraneous dead leaf tissue. Each of the original central spots will be seen, especially when examined on the under side, to be surrounded by a very dark, almost black zone, that demarks it from the original pale-coloured border. In time the central spots fall out, when the leaf appears per- forated (should the expanding rims of several not have united) as if a charge of large shot had been fired into the bush and riddled all its leaves. 829. At one seed garden, visited by me, I found a large percent- age of the fruit-bearing bushes covered with this blight. I asked the superintendent if he had tried to check the spread of the malady for, to say the least of it, such wholesale destruction of the leaves must weaken the seed. I also enquired whether he had ever taken any steps to ascertain whether the fungus was communicable through the seed. I was examining the fruits, many of which showed on the external rind similar destruction to that on the leaf, when the Native overseer informed me the disease could also be seen on the seed itself. I opened up one or two fruits and found, just as the overseer stated, that the seed leaves (cotyledons) were distinctly invaded by very similar fungal spots. Whether the embryos are simply thereby killed, and the seeds rejected as dead, during the selection that takes place before consignments are sold, or they carry the disease to the nursery and to the tea garden, I was not able to ascertain. But the suggestion here made seems to call for investigation. I BROWN SPOTS WITH PALE RIM. Description. Leaves Perforated if by Shot. Must Weaken the Seed. Embryos seen to-, bear Fungal Dis- colourations. 430 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. BROWN SPOTS WITH PALE RIM. Disease Com- municated by the Seed. Margin of Leaf Eaten Away. Lea\ Folded tres led Over Near the Base. Con/, with para. 77. undertook to germinate some of the seed, taken from a particularly badly infected tree, if the superintendent would send me some when ripe. Shortly after, I was told a supply had been despatched for me, but that unfortunately the coolie on making for the railway station had been robbed of his parcel. I was thus deprived of the opportunity of investigating a point which I venture to think of considerable interest. But I may add that, during my further explorations, I carefully examined the plants said to have been raised from seed derived from the seed-garden in question, and failed to establish any relation between the source of seed supply and prevalence of this fungus. 103. (c) MARGINAL CORROSION. (Botanical Specimen No //pjy.) 830. Another fungous disease, in some respects like the last, is fortunately not common, but does considerable damage where it occurs. The texture of the leaf, generally on one side but may be on both sides of the midrib, shows pale discolorations. These enlarge until considerable portions of the leaf are invaded and become pale coloured. They then gradually change into brown and a fungus appears on the margin, and eats inwards until the leaf may be reduced to a midrib and few fragments of the blade. As the decomposition advances, a pale line of demarcation is moved forward and the texture behind crumbles away. I met with this in one or two gardens only, of the Dibrugarh Dis- trict. But this malady, as also the last mentioned, may, however, be associated with grey-blight, and are thus not very readily recognized. It is in consequence probable that this blight is more extensively distributed than might at first sight be supposed. 104- (c) LARGE LEAVES TURNED OVER AND ATTACKED BY A FUNGUS NEAR THE BASE. {Botanical Specimens Nos. 11145, 11323.) 831. Closely allied No. 103, in external appearance, are two other conditions with which the practical man is familiar. In a peculiar form of the indigenous plant, with specially large thick, dark green, hard leaves, a portion of the base of the leaf (on one side of the midrib) turns purple. As this progresses the top portion of the leaf falls over and the discoloured patch gradually changes into brown. Soon thereafter it is invaded by a fungus, but whether saprophytic or parasitic I could not be certain. The part dies in time and becomes decomposed Tea Pests and Blights. 43 Brown Blights on the Leaves. so that the leaf is eaten away in a manner not unlike the marginal corrosion above described. This occurs all over Assam, but on the jat of tea denoted, and no other. 105. (c) MARBLING OF THE LEAVES. (Botanical Specimens Nos. 11335 and 11928.) 832. It is not uncommon to find what might be spoken of as an anaemic condition. All the leaves of a particular bush, or it may be a section of a bush, turn pale green with portions even pure white. At an early stage the margins of such leaves wither, shrivel up and become attacked by saprophytic fungi. This appears to be a con- stitutional disease, or may be due to the presence of some grub eating the roots or a fungus on the roots. I observed, for example, that the condition indicated prevailed to a very great extent in gardens affected with what the planters know as " Red Rust," though I also found it in instance where I could detect no trace of that alga. How- ever, from the point of view here specially desired to bring out, the margins of such leaves in time become eaten away, in a manner very similar to that which I have described as a fungus that produces a marginal corrosion of the leaf (No. 103). 1 06. (c) CHESTNUT PATCHES BUILT UP OF CONCENTRIC ZONES. (Botanical Specimens Nos. 11338, 11905 and 11935). 833. All over Assam, both on the tea and on the leaves of many jungle plants as well, one comes across very frequently examples of a beautiful fungus or of several species of fungi of the kind it is here desired to specialise. This commences by a minute point, which turns to a chestnut colour, the leaf tissue then shrinks in thickness and becomes quite dry. Layer upon layer thk widens and absorbs veins, midrib, or any part of the leaf with which it comes in contact. Zone upon zone, each clearly demarcated like the layers of exogynous wood in a transverse section. As the fungal patch enlarges, it seems to abstract moisture from the adjacent tissue, for the leaf contracts, thus causing the perfectly smooth and shining fungal patch to show up very clearly. The leaf is slowly killed and in time falls to the ground, but as only a leaf here and another there, is so invaded, the fungus can hardly be regarded as a blight. 834. But in one garden I came across a slight modification of this condition where the fungus or what appeared to be a similar fungus FUNGAL PATCHES In CONCENTRIC Variegated Leaves. Con/, with para. 8 (tit. Red Rust. Decom- position of Leaf Tissue by Fungal Patches that Expand in Zones. 43* Report of Investigations in Assam Vegetable Parasites of the Tea Plant. BROWN RINGS. Similar Condition Assuming the Prevalence of a Blight. Bushes are Defoliated. Superficial Brown Patches with Embracing Rings. was so prevalent and destructive as to rise to the position of a distinct blight. Between the veins, the tissue became swollen or bullated, with irregularly shaped alternating pale-coloured and dark patches. The plant was in fact richly variegated with many leaves straw coloured, deepening into yrange and finally brown. At this stage every leaf bore one or more dark brown fungal patches that widened in cir- cumference by adding zone upon zone as in the condition just men- tioned. But only in the advanced stages did these concentrically formed patches show through to the under surface. 835. In the advanced stages of this blight the plants became leafless, and in many respects thus resembled the condition characteristic of grey-blight. (Pestalozzia Guepini.) At no stage of this blight, however, were the leaves- seen to be grey, nor the invaded portions built up of numerous centres that had coalesced. That is to say, the patches do not originate from a multitude of minute spots, but from a very few points rarely adjacent and only very exceptionally coalescent. Moreover, their formation is restricted to the spaces between the veins which, at first almost straw coloured, gradually deepens until the concentrically formed fungal patches are fully developed. 107. (c) BROWN RINGS ONE WITHIN THE OTHER. (Botanical Specimen No. 11882.) 836. This very remarkable leaf discolouration I only came across on one or two occasions. At Ligri Pukri I found a clump of half a dozen bushes affected with it ; again at Hautley a few more ; and at Dum Duma it seemed fairly abundant. In all these instances, however, it in- variably appeared on Assam indigenous plants. The bushes were stunted, the leaves abnormally broad, and the marginal serrations hard and sharp. The leaves were spotted all over with curious markings of a dark green to brownish shade. These originated with a small circular spot, that showed on both the upper and under sides, as if a drop of gum had hardened on both surfaces simultaneously and formed a rather thickish superficial patch with a thick rim. Then semi-circular bands of discoloured tissue, one within the other, imbricating or uniting into more or less perfect rings, were seen to be arranged around the central patch, each of the embracing and surrounding bands being separated from the other by about an eighth of an inch of pale green leaf tissue. On the surface of the central patch a few black circular Tea Pests and Blights. 433 Brown Blights on the Leaves. apothecia-like bodies were recognised, but these, in all the specimens examined, were but imperfectly formed so that I was unable to dis- cover the spores. To a certain extent the central patches resemble those of grey- blight, but apparently they never unite together, and the embracing circles of discoloured tissue (which in the driedWeaf become almost black in colour) are most peculiar. In some respects these striking discolourations recall the species of epiphyllous fungi referred to the genera of Phyllosticta or Depazea. They can hardly be called diseases though they denote a want of vigour. Io8. (c) BLACK FUNGI ON THE LEAVES. 837. Under the account " of Red-rust " mention will be found of a black fungus that is often seen on the tea leaves, in association with the orange-red patches of the alga (Cephaleuros verescens). It not infrequently happens that in a damp situation, or near the jungles, this fungus is very prevalent, without being accompanied, in any very special manner, with the foliar patches of red-rust. The fungus to which I allude is, however, purely epiphyllous, and further than possibly harbouring other pests does not appear to be injurious. {Botanical Specimen No. 10424.) 838. In connection with the account of Scale-insects, mention has also been made of another black fungus found on the tea leaves. A sample of this form having been furnished to the Director of the Royal Botanic Gardens, Kew, it was found to be Capnodium Footii, Berkl. and Desmaz. Mr. Dyer in furnishing the determina- tion, wrote that the species had not previously been recorded as met with in India, but that it was common on the Camellia, in cultiva- tion in Europe, and was the species that blackened the lime-trees (Tilia), in the latter case appearing in association with the honey-dew aphis. {Botanical Specimen No. 9060.) LXXI. Blights on the Stem. I0p. (a) Stilbum nanum, Massee, sp. nov. (See foot-note to page THREAD BLIGHT ALSO KNOWN AS WITHER BLIGHT. References. Journ. At*ri.-Hort. Soc. Ind., Vol. I. (. s.) Proc., i$th July 1868, p. liii; Vol. VI., Proc., 2?th Feb. 1873, P> * > ****** *&* March 1874, p. xiii ; jour., V 1 1., pp. 258-262 ; Vol. X., Proc., 2jth March 1896, p. 470 ; Vol. XL, 26th March 1897, p, 601 ; Tea Planter s VadeMecum, 104-105 ; Bamber, Chem. and Agri. Tea, f>. 257; Chris- 28 BLACK FUNGI. Con/, with paras. 514, 617. Associated with Scale- Insects OP Aphides. Con/, with paras. 46(2), THREAD BLIGHT. Con/, with paras. 39, 173, 480, 482. 434 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. STILBUM NANUM. Fruiting, structures. Rhizold Filaments. Sclerotia. Probable Method of Reproduction. Found in Assam, Cachar, Darjeeling and Andaman Islands. tisun (White Thread Fungus), Home and Colonial Mail, Jan. ist, i8gj ; Dr. D. D. Cunningham, Scientific Mem. Med. Officers of the Army of India, Ft. X., pp. 20-22. (Reg. No. 138 ; Botanical Specimens Nos. 11147, II 334> 11911, 11931, 11932, 11966, 11968, 11970, and 11988.) 839. HISTORY. The above references to Indian publications show that this fungal tffight has been recurrently brought to attention, as an enemy of tea cultivation, during the past 30 years. The late Rev. M. J. Berkeley* was the first mycologist apparently, to whom samples had been sent for examination, and DP. D. D. Cunningham, C.I.E., the most recent writer on the subject.-f Briefly it may be said that until quite lately no one had seen what might be called the fruit-bearing structures of this fungus. The rhizoid filaments (the threads of the tea planters) are the only parts that have, therefore, been available for examination. In popular language these might be regarded as corre- sponding to the root and stem of higher plants ; and hence in the absence of fructification, the species might be characterised as per- petuated by cuttings. It is well known, however, that many fungi can and do exist indefinitely in that condition, or change their structural peculiarities in the fruiting stage to such an extent as to escape detec- tion of the two forms being parts or states of the same species. DP. Cunningham, it will be observed from his report, which I have taken the liberty to quote very freely, has suggested, by analogy with a similar blight on Ficus Stipulata, that the fungus in question may belong to a group that produces SCLEROTIA. That is to say, fungi that form hard tuber-like very minute bodies, composed of reserve material, which on being thrown off by the mycelium (the structure in this species that has given the name thread-blight) remain dormant for a time. On the return of favourable conditions they germinate or sprout and pro- duce temporary fructifications which reproduce the species once more in its rhizoid condition. Fungi that assume the habit briefly indi- cated, are naturally very obscure, and careful research conducted with fresh material is necessary to discover their various stages, and hence their eradication is often a matter of considerable difficulty. 840. This fungus was first sent to the Agri.-Horticultural Society from Upper Assam, but it is subsequently mentioned as occurring in Cachar and in the Duars. DP. Cunningham mentions the fact that the * Quarterly Jour, of Microscopical Science (1875), pp. 1303. f See foot-note to page 419. Tea Pests and Blights. 435 Blights on the Stem. THREAD BLIGHT. on which it Occurs. Ascending External White Threads. specimens examined by him had been furnished by Brigade-Surgeon Lieut-Col. Sir George King, K.C.I. E., from Darjeeling, and that Surgeon-Major D. Prain had found it on tea in the Andaman Islands. ; 841. I assume that the thread-blight seen in the jungles of Assam, is other Plants the same form as that found on tea. If so, it occurs on a very large num- ber of widely dissimilar plants, of which may be mentioned bamboo and Dillenia indica (the utengah of Assam) as the jungle plants on which it is specially plentiful, and Eriobotrya japonica (the Loquat) and Achras Sapota (the Sapodilla plum) as the fruit trees on which it very frequently occurs. It is, however, by no means un- usual on the Mango and may be recognised at a distance on fruit trees by a clump of withered leaves near the extremities of certain branches. 842. DESCRIPTION. In the early months of the season, this blight may often be seen on the lower part of the stem. The name thread-blight sufficiently describes it. A soft woolly white thread is seen to adhere to the stem and to develope upwards. It is very lightly attached to the bark. In some few instances I have been able to trace a direct connection with buried prunings, bearing the blight, and fresh inva- sions of stems. In others the thread seemed simply to emerge from the ground. This latter circumstance might be supposed as corro- borating Dr. Cunningham's suggestion of SCLEROTIA originating new threads. Usually, however, unless removed, the thread is to be seen mainly upon the branches. Very often it does not occur on the stem? and consequently has no connection with the ground. In that posi- tion it may continue from year to year, the portion that may be left i after pruning starting the fresh attack on each succeeding year's shoots. On running up the young twigs it forms slight thickenings at j the joints from which offshoots go to the leaves. The remainder of the thread at each joint then sweeps round the twig to the position ! of .the next leaf, and soon. Each leaf gets its own portion of the thread by which its destruction is effected. On reaching the leaf, the fungal thread thickens on the petiole, twists round and runs up the midrib where it expands into a soft felted layer that ultimately covers the whole under side of the leaf. I never came across an in- stance where the felted expansion was on the upper surface of the leaf. In this respect thread blight differs essentially from grey-blight, which occurs exclusively on the upper side of the leaf. 28 A Threads Usually Seen on the Branches. Special Threads Sent off to Each Leaf. Under Surface of Leaf Felted. 436 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. .BUM *UM. Leaves Turn Brown. Withered Leaves Fastened to the Branches Bushes Look as if Filled Wlffied Leaves Carried there by a Flood. It Thins t Thins out the Bush. isition of tion itivt 843. Once the under surface has been coated, the leaf begins to fade and gradually turns brown, hence no doubt the name " Wither Blight " given to it by one writer. But coincident with the change in colour the leaf gradually closes downwards until it comes in contact with the twig or stem when it becomes firmly attached, by fungal filaments that hold it securely, even though the petiole may have severed from the twig. Held in that position the final decomposition of the leaf is accomplished, and the somewhat curious appearance is presented of a tuft of brown rotten leaves adhering around the base of the branches, as if carried there by a flood. The bush looks green on the top, and for a time may be even vigorous, but as the thread advances, leaf after leaf drops until ultimately the bush becomes banjhi, the thread then pushes forward to the terminal buds and the invaded twigs are killed. 844. But there is one peculiarity that I must here mention ; the whole bush is rarely invaded at once. One branch or at most two or three branches are attacked, so that the destruction accomplished may escape detection. Many planters even laugh at the idea of danger from this blight. I have been told over and over again, " Yes, I know that is thread-blight, but it does not do much harm. It has to my knowledge been on that particular bush for some years, and I have even noticed that many bushes throw it off entirely and are apparently little injured by it." Now what it does do is to thin out the bush. It thus differs essentially from grey blight, which invades one side and kills perhaps twenty or thirty shoots, thus deforming the bush. But the result in both cases is very nearly the same, namely, the des- truction of a certain number of the flushing shoots. In the one case the injury is distributed, in the other, concentrated ; but grey blight is more dangerous from its being more rapidly communicated from bush to bush than would appear to be the case with thread-blight. 845. The following passages from Dr. D. D. Cunningham's reporton this fungus will be found both instructive and valuable as explaining the probable method by which the leaves and buds are killed : "The peculiarity to which it owes its name consists in the presence of conspicuous white cord-like strands of mycelium which run along the surface of the shoots from one leaf to another. They consist of rhizomorphic aggregates of filaments which do not appear to be concerned in the direct acquisition of nutritive material, but merely to serve as means of travel from one nutritive site to another. They are: Tea Pests and Blights. 437 Blights on the Stem. purely superficial, and may readily be rubbed off, leaving the surface of the bark beneath them seemingly quite intact. This, however, is not the case when the mycelium reaches the foliar surfaces. When the extremity of a cord reaches the base of a petiole, it is either completely diverted outwards along its course, or divides, giving off a branch towards the leaf, whilst the rest of it continues to ascend along the axis. When the mycelium reaches the under surface of a leaf, the cord breaks up and ramifies indefinitely, covering the epidermis with a coat- ing of white filaments, and as this advances the tissues of the lamina throughout become discoloured and die. Where, on the other hand, it comes in contact with the upper surface, only a limited amount of ramification occurs and growth is soon arrested without visible injury to the leaf. It thus behaves in precisely the same fashion as the mycelium of the common sclerotial blight of Ficus stipulata does." " The nutritional relations of the mycelium to the upper and lower surfaces of the leaves are quite distinct. The upper surfaces are apparently related to the mycelium just in the same fashion as the bark of the shoots is ; they merely serve as a supporting surface over which mycelial filaments deriving their nutrition from other sites may travel, but the under ones are clearly a site for the acquisition of large supplies of fresh nutritive material, as indicated by the indefi- nite and rapid growth of mycelial elements occurring in connection with it. But the great difference which exists between the upper and under surfaces of leaves generally in their nutritional relations to parasitic or facultatively parasitic * fungi lies in the much greater facilities which the latter afford for the. penetration of mycelial filaments into the interior of the host-tissues, both from their gene- rally less resistant texture, and from the great excess of stomatic ori- fices which they present. Taking this into account, together with the destructive effects following the access of the mycelium to the in- ferior foliar surfaces, and the close parallelism of the phenomena with those present in the case of the blight of Ficus Stipulata, there is little room to doubt that such penetration does occur. At the same time it must be allowed that none of the specimens which I have had the opportunity of examining have afforded any actual demonstration of the fact. This, however, is not very astonishing, considering the [* Facultative parasite an organism that is usually saprophj tic but which may become wholly or in part parasitic. G. W.] THREAD BLIGHT. U e Qlt, ferent when the _FIlament 3hes the ives. Reache Leav Nourishment Derived from Under Surface of Leaves* Parasitic 8BRSS? 433 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. STILBUM NANUM. iimllar fungal [lights. Observation Necessary. exceptionally dense texture of the leaves and the fact that in all the specimens the tissues had more or less completely dried up ere they were subjected to examination conditions which are specially calculated to render the detection of intrusive mycelial elements a matter of extreme difficulty. In the case of many uredinous blights, in which the presence of very large numbers of patches of fructifica- tion unequivocally implies the existence of an abundant and widely diffused mycelium within the substance of the tissues, the demonstra- tion of it is frequently a matter of very great difficulty, even in perfectly fresh specimens, and where the host-tissues are dense and the parasitic elements have been subjected to desiccation, the difficulty is naturally greatly increased." " As has been already pointed out, the phenomena attending the spread of this disease are closely parallel to those occurring in the case of the sclerotial blights of Ficus Stipulate and Evol- vulus nummularia. The principal distinctive feature lies in the definite cord-like arrangement which the mycelium assumes in passing from one nutritive area to another. The distinction, however, is not an absolute one, for, although in the two latter blights the my- celium never forms such definite cords, it does tend to become aggre- gated in the form of strands in passing from one leaf to another or when spreading out from the edges of an exhausted leaf over neigh- bouring non-nutritive surfaces such as glass or water. The distinction thus is one of degree and not of kind. In none of the specimens which have yet reached me have there been any traces of true sclerotia either within or on the blighted tissues or in the substance of the mycelial cords, but this may very probably have been owing to the fact that the normal development of the mycelium was arrested by the conditions to which it was subjected after the affected shoots were detached. In certain cases renewed active growth occurred in some of the mycelial cords when subjected to the influence of a moist atmosphere, but in the absence of fresh foliar surfaces as a source of new stores of nutritive material it was soon arrested. The pheno- mena certainly render it extremely probable that the disease is a sclerotial one, but the question is one which can only be determined in a site in which both parasite and host-plant are at home, but in any such site a little careful observation would be all that would be necessary to decide it. " Tea Pests and Blights. 439 Blights on the Stem. 846. DEPREDATIONS. In one garden visited by me along with the superintendent, both thread-blight and grey-blight were present, often on the same individual bushes. We marched right and left through the garden and made an estimate of the number injured. At the lowest possible figure 50 per cent, showed one or both of these blights. The loss in that garden will have to be expressed in the returns for years to come, unless the suggestion I made has been acted on, namely to collar prune the entire garden and burn the prunings. There is no other remedy. This was certainly, however, an extreme case, but I mention it as showing what may and indeed sometimes does exist. Thread-blight is very prevalent in Assam and must be year after year weakening the plants and lowering the yield, over a large portion of the tea area. It is one of those insidious maladies that are often neglected until almost too late. That bushes may appear to throw it off is entirely a matter of pruning. Should the pruners have gone sufficiently low, to remove all the invaded portions, the disease very possibly may disappear. But if any portion of the thread be left, that will assuredly continue the destruction, and year after year sap the life of the bush. By killing a large number of its branches it will also steadily reduce its yielding capacity. 847. But the withered leaves, adhering to the bush, are the chief agents of dispersion of the disease. I have repeatedly found tea leaves or jungle leaves, more specially the utengah adhering to bushes near a point where a new start had been given to the blight. It would thus seem that the disease is readily transmissible and may be diffused all over the garden if a. few bushes are allowed to furnish withered and mycelial-bearing leaves, to be carried by the wind. These leaves, on coming in contact with a fresh plant, at once put out a small filament that unites the diseased structure to the new host. But in passing I would desire to repeat that a similar state of affairs would seem to occur in grey-blight, since under that blight the observation has been made that the diseased leaves become attached to healthy bushes. 848. REMEDY. The following passage completes Dr. D. D. Cun- ningham's account of this blight : " In the absence of precise informa. tion in regard to the true nature of the parasite and the exact form and sight of development of the reproductive apparatus, all that can be suggested with a view to the prevention of the disease is that when- ever it makes its appearance all infected shoots should, as far as THREAD BLIGHT. Grey-blight and Thread- blight Often Associated Together. 50 per cent. Affected. Pre'vaT/tin Yielding Capacity Lowered. Mode of Communica- tion. All Affected Parts should be Removed. 440 Report on Investigations in Assam Vegetable Parasites of the Tea Plant. STILBUM NANUM. Collar Pruning in Bad Cases. Yield fell from 8 to 6 maunds. possible, be at once removed and burned. Such treatment will prevent the development of any true sclerotia, should such bodies be normal constituents in the developmental cycle of the parasite, and will at the same time secure the destruction of the dense mycelial cords on the bark the tissue of which does not merely serve as a means of spreading the disease from one leaf to another, but is also capable of retaining its vitality in a dormant condition for some time under conditions fatal to the mycelium generally, and is therefore capable of ensuring the persistence of the disease during periods pro- hibitive of its active extension." 849. There is very little further to be said regarding the remedial measures for this blight. All that is wanted is careful pruning when and where the blight appears. But should it have got established in a plot of tea, the bushes very possibly may have been so severely injured by that time that collar pruning may be the only cure. If heavy pruning be thought preferable, every portion of the stem and branches should be thoroughly lime white-washed so as to kill any pos- sible germs, and the prunings should be carried to'the path-ways and at once burned. If the attack be only a mild, the Bordeaux solution such as recommended for lichens (foot-note to page 6) would suffice. The following passages may here be given from my diary as amplifying and illustrating the foregoing remarks regarding this blight : Diary Notes on Thread-blight. 850. On the 6th April 1895, I had a conversation with Mr. B., Super- intendent of , in the Sibsagar District, on the subject of thread- blight. As it may be found of interest the chief ideas brought out have been thrown together in the form of question and answer : 1. Have you had this blight severely in your garden ? Yes, in a plot of 38 acres, where plants equivalent to 8 acres were so badly attacked that the yield of the plot fell from 8 to 6 maunds. 2. Is there any season of the year for its appearance? No. It starts from the bottom of the bush and spreads upwards. 3. What treatment did you adopt P Pruning back and white-washing in December and January. 4. What result ? The bushes are throwing out young shoots, though later than the others in the clump. There is now no appearance of the blight. 5. What do you think is the cause of the blight ? Damp soil most probably. The 38 acres had been freely drained the year before pruning-, and there has been no further draining. Prior to that it had been drained every 100 feet ; on the occasion mentioned, it was drained every 50 feet. 6. Prunings were buried when the bushes were only top pruned, when cut back they are burned. Tea Pests and Blights. 441 Blights on the Stem. 7. Do you think the practice of burying the prunings could be the cause ? No, because to my knowledge in many other gardens where they regularly do so, the blight has not appeared. But might not that fact be due to the prunings having been free from the disease. You have no absolute knowledge of a garden affected by the disease where the system of burying could be said to be, or not to be, the cause of a rapid distribu- tion of the disease. I have not. 8. Do you think the disease is due to the proximity of jungle P I do not know, but the blight is common in the jungles and on many different trees and bushes. In a garden in the Nazira neighbourhood (visited April I2th), thread- blight was found prevalent. It may be recognized by the leaves of last year, being not only dead, but mostly reduced to skeletons, and appearing like tufts of leaves washe'd into the bush by a flood. On the top of the bush the new flushing shoots may be seen like a green crown to a rotten bush. The old and dead leaves are literally bound together to the stem by the long white filaments of the fungus. (No. 11247.) At a garden inspected on the way to Amguri, April igth, I found thread-blight not uncommon, and it seemed to be attacking only one side of the bushes. In the same garden the sandwich caterpillar was very prevalent, especially on the bushes with thread-blight on the stems. At a garden visited by me on the 25th April, in the Jorhat Division thread-blight was fairly bad, but wherever it appeared had been eradi- cated by severe pruning. In a garden visited on the 2nd May (in the Golaghat Sub-Division) I found that thread-blight was worse than in other gardens of this neigh- bourhood, and, moroever, it was found in intimate association with the sandwich caterpillar. In one or two adjacent gardens of Dibrugarh District, visited on the 25th and 26th June, I found thread-blight very bad. The superinten- dents informed me that they had tried pruning to' get rid of the malady. The bushes were cut back very low in December and prunings burned. The blight had re-appeared occasionally (though not bad), thus showing that the pruning had not been sufficiently drastic. Another plot was not pruned, but the diseased bushes marked and observed. These were found still badly affected, and others now invaded. It was thus proved beyond doubt that the bushes do not throw off the blight as many planters affirm, but that, on the contrary, it most distinctly spreads from one bush to another. These experiments were most instructive as they conclusively demonstrated the seridus nature of this disease. I accord- ingly recommended that all diseased branches should be lopped off now, and that drastic pruning (if not collar pruning) should be pursued at the ordinary pruning season. If not collar pruned, all stumps left should be freely coated with lime white-wash or Bordeaux mixture and the prunings burned as carefully as possible. At Jaipur thread-blight was fairly abundant, though, so far as I could discover, the sandwich caterpillar did not exist. THREAD BLIGHT. Burying Prunings. Blight is Common in the Jungles. Leaves Reduced to Skeletons. Sandwich Caterpillar Commonly with Thread Blight. Golaghat. Dibrugarh. Severe Pruning. Lime Whita- washing. Jaipur. 44* Report of Investigations in Assam Vegetable Parasites of the Tea Plant. STILBUM NANUM. North Lakhimpur. Is Supposed also to Attack the Roots. Mijika Jan. Giladharee. Koliabar. Nowgong. Affects of Thread-blight, Grey blignt and Red-rust, At a garden in the Dihrugarh District, visited on June 27th, I found no thread-blight. At Dum Duma, visited on the 3oth June, thread-blight was difficult to see owing to dense dome, but found some bushes affected. At Patalipam (North Lakhimpur), I was told this blight never ap- peared bad, but, if left on the bushes, it ultimately attacked the roots as well as the branches and killed the plants. It is distinctly communicable and comes from the leaves and twigs of jungle trees blown on to the tea. It may be checked by careful pruning and burning the prunings. It is more serious if communicated to the roots first, as it kills all the young roots. This, Mr. Alexander is of opinion, takes place when prunings with thread-blight are buried. Having crossed the river to the north bank, I was most curious to compare the blights of these gardens with those I had examined on the south bank. At Bordeobam I found thread-blight fairly plentiful. If anything, this blight would seem to be favoured by the shade of the Sau trees. At Gopesadarhu, visited on the i2th July, thread-blight was found occasional. At Mijika Jan, visited on I3th July, I found thread-blight very common. A portion of Giladharee garden, visited on the i4th July, was found to have at least 40 per cent, thread-blight. (Nos. 11968 to 11970.) On the 1 6th July thread -blight was found on the lower portions of Koliabar. At Salonah, Nowgong District, visited lyth July, I found thread-blight frequent in some places, more especially in confined situations. Thread-blight Operates Below. At Amluckie, visited i8th July, Mr. J. A. A. Hunter took me to one portion of the estate that might be characterised as a heavy black damp soil, badly requiring to be deep sub-soil drained. The plot of land to which I allude was enclosed by jungle. I found it to have perhaps 20 per cent, of its bushes severely affected with thread-blight, and very often grey-blight as well and even red-rust. I endeavoured to demonstrate the effects of these blights by selecting bushes that manifested their peculiarities. Thread- blight kills off a certain percentage of the two and three year old shoots of the branch or branches on which it occurs, and thus leaves the bush full size, but with perhaps less than half its normal producing shoots. " Red- rust " is somewhat similar in its action in so far that it thins out the flush- bearing timber, but grey-blight is entirely different. It kills the leaves, buds and shoots over a compact portion of the bush, and thus cuts a hole into it or, if very severe, may surround the bush, then work upwards from the circumference, and finally down through the centre, in this case practi- cally or actually killing the entire bush. If only a slight attack, the disease may exist as a fringe round the circumference, or as a patch on one side of the bush. The affected leaves and shoots fall off and the bush apparently recovers, Grey-blight, by being concentrated, is more Tea Pests and Blights. 443 Blights on the Stem. conspicuous and the dead leaves lie on the top instead of being hid below. It works from the top downwards (or from the outside towards the centre), while thread-blight operates from below upwards, and is thus concealed by the healthy leaves above. In Red-rust all the leaves of the invaded shoot tarn pale, some of them even white, and then simultaneously die as the blight advances. But they have simply withered and showed no diseased formations on their surfaces. The seat of the disease is on last year's wood, all above that being gradually starved and killed. At Solal (visited i8th July), Mr. Moir showed me thread-blight which, he said, was becoming somewhat serious, but he had no other pests of any consequence. I did not personally investigate the garden as 1 was pass- ing through on my way to Silghat. At Tezpur on the 2oth July, I was taken to see a small plot of land on fairly heavy soil, and surrounded with jungle that had, according to the estimate of the manager, 40 per cent, of the bushes affected with grey- blight and thread-blight. The land was cold and sour, the clods show- ing a white efflorescence on exposed portions a sure sign of defective drainage. 1 10. (c) Cephaleuros virescens, Kunze. (Mycoidea parasitica, Cunning., Cephaleuros Mycoi- dea, Karsten.*) THE RED-RUST of A ssam Planters; the WHITE-BLIGHT of the early writers. References. Cunningham, Mycoidea parasitica, in Trans. Linn Soc., 2nd series, Vol. I., 301-316, tabs. 42, 43 ; also An Entophytic Alga occurring on the leaves of Limnanthemum indicum, with Notes on a Peculiarly Parasitic Variety of Mycoidea, in the Scientific Memoirs by Medical Officers of the Army of India, Part III., pp. 35, 40, pi. 1 ; and Bark-blight caused by Cephaleuros virescens, Kunze, in Scientific M ems., etc., Part X., pp. 17-20, pi. III. ; H. Marshall Ward, Trans. Linn. Soc., (1884) Vol. II, Second Series, Botany pp. 87-115, Plates 1820; Diseases of Plants by Dr. Karl Freiherr von Tubeuf, transl. by W. G. Smith, 552 ; Tea Planter's Vade Mecum, 105-106. (Reg. No. 139-, Botanical Specimens, leaves 10426 : shoots 11989.) 851. HISTORY. So far as I can discover, this blight first began to attract attention about 1880. It was then known as " White Blight,' because of the peculiarity that the leaves of the twigs invaded by ii were observed to become variegated, ultimately pure white, as one writer remarked making the bushes resemble " white leprosy." I has similarly received the name of " Red-rust," because of the red- coloured diseased patches seen on the bark of the two or three year old shoots. 852. DISTRIBUTION. I have no direct evidence that it occurs as a dangerous tea blight in any other locality than Assam, and even in RED-RUST. Solal. Tezpup. RED RUST. Conf.'with paras. 39, White-blight. Red- Assam. 444 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. CEPHALEU- ROS VIRESCENS. Found in Nazira, Nowgong, and Tezpur. Con/, with Distribution Wrong Reported from Dibrugarh. Latitude of Nowgong and Tezpur. It is an Alga. Assam it is most erratic. I found it in two adjacent gardens in the Nazira Section of Sibsagar ; in half a dozen or more gardens within a compact section of Nowgong ; and in two or three gardens in Tezpur. The Nazira gardens in question might be spoken of as suffering from defective drainage. The Nowgong hills probably give to the tract of country below them a considerably different climatic condition to what prevails above (namely in Sibsagar and Dibrugarh), but that difference could hardly be accepted as sufficient reason for the prevalence of the blight in Nowgong, nor for its absence from Dibrugarh and practically also from Sibsagar. The report of its occurrence in Dibrugarh is, I believe, due to a garden in that district being under the management of a Company that has its head-quarters in Nowgong. Certain letters, having been issued by the manager during inspection duty in Dibrugarh, gave the reputa- tion of the blight being found in that district. But if excessive rainfall, high humidity and even occasional inundation, be viewed as circumstances likely to favour the appearance and distribution of this blight, it might naturally be looked for in North Lakhimpur and the gardens of the north bank generally, but to the best of my know- ledge it nowhere occurs until on descending the valley the latitude of Tezpur and Nowgong is reached. It is thus significant that this blight should be confined to the portion of the Assam Valley indicated. Whether or not it exists still lower down, for example, in Gauhati, Mungledai and Goalpara, I am unable to say, but the restricted nature of its present distribution is certainly highly signi- ficant. 853. An Alga not a Fungus. But I must hasten to explain that, unlike the majority of the vegetable parasites, indicated in the fore- going pages, this blight is not a fungus but an alga. That is to say, it belongs to the natural order of plants best known by the seaweeds and the fresh water algae. In general terms, these may be said to differ from the fungi, by their more or less aquatic habit, by their being often highly coloured (frequently green), and by their being only very exceptionally parasitic. The blight with which we are concerned is one of those remarkable exceptions, for it is distinctly parasitic, and to the ordinary observer could hardly help being viewed as a fungus. But it is unfortunate that it has come to bear the name " Red Rust " since the term rust has a very restricted signification, Tea Pests and Blights. 445 Blights on the Stem. ., to one group of fungi, with which" this blight hardly bears even a superficial resemblance. Two Phases in its Life. There is another point that had better be here mentioned there are two widely different phases in the life of this alga ; in one it is found on the leaves of the tea plant, and is comparatively harmless ; in the other, it infests the bark and superficial structures of the young shoots, and is in that case a dangerous parasite. In its harmless condition it exists throughout Assam, in the Duars, Darjeeling and Ceylon. It may, and I have little doubt does, exist also in the other tea districts, though I have no knowledge of the fact. It is very common on the wild tea, though I am not aware of the injurious form having been found anywhere except on cultivated plant. 854. Literature. -We oweto;Brigade-Surgeon-Lieutenant-Colonel D.D. Cunningham, C.I.E., practically all the knowledge we possess on the subject of this very remarkable organism. The first of his scientific papers (mentioned above), deals with the epiphyllous condition, and de- scribes the life history of the alga in every detail. That monograph may be said to bring out three very important facts, (a) that it is distinctly a parasitic species, (V) that, in what might be spoken of as the start- ing point of its structural formation, it exists as a minute flattened disk of algal cells which is primarily developed above, but subse- quently as a secondary formation, immediately below the epidermis (or cuticle) of the leaf ; and (c) that the superficial disk may be parasitised by a fungal filament, the combined growth of the alga and fungus giving origin to various forms of LICHENS allied to STRIGULA. It would be beyond the scope of a report on tea planting, more especially on the pests and blights of the tea plant, to enter into detail on the many highly instructive scientific aspects of Dp. Cunningham's investigations, but the three facts mentioned are directly connected with the practical considerations that I wish to elucidate. The second of Dr. Cunningham's papers deals still with the phase of the alga as found on leaves, and gives details of an instance in which its parasitic character is unequivocal. 855. In passing, it may be here remarked that one of the many re- markable peculiarities of this organism is the fact that it is by no means confined to the tea plant. It exists throughout the tropical regions of India on an extensive series of widely different plants. In Assam RED-RUST Two Phases in its Life. In its Epi- phyllous Phase it Occurs Practically Throughout the Tea Districts. Three mportant in its istory. Impo Facts Life Hi Is not Confined to 446 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. CEPHALEU- ROS VIRESCENS. Not Found on Soft-leaved Trees. Localities Where Found. Orange-red Spots on the Leaves. ASE EPR EXUAL it might almost be said to occur on any tree or bush, the leaves of which have, like the tea plant, a fairly hard and polished epidermis on the upper surface. Thus, for example, it is common on the Mango, the Letchi, the Nahor, the Satian, the Sum, the Adakuri^ the Cinnamon, and many others. But it is not likely to be found on the Sau, the Bukhain, the Sam, or other soft-leaved trees common in and around the tea gardens. 856. The third, and to the tea planters the most important, of DP. Cunningham's above enumerated papers, deals with the phase in the life of the alga when, instead of living on the leaves, it attacks the bark of one or two year old tea shoots, and becomes a dangerous parasite. In the remarks which follow, I shall take the liberty to reproduce this most valuable contribution, but I shall do so under three separate paragraph headings to which it has in any case prac- tically been referred by the author. 857. DESCRIPTION. To discover this blight, examine bushes found under the shade of any of the hard-leaved trees named above, or bushes growing near the jungle, or on plots of tea land imperfectly drained or badly ventilated. If the nursery be surrounded by jungle, examine also the seedlings, for you may find these the source from which this blight gets dispersed over the garden. The older leaves of the bushes, in most of the positions mentioned, will almost invariably be found to bear on their upper surfaces numerous orange- red spots that may range from an eighth to half an inch in diameter. Even to the naked eye these spots may be seen to support, especi- ally on the slightly thickened circumference, a crop of minute erect filaments. The centre of the larger spots may also be observed to be dark coloured (sometimes almost black) the tissue of the leaf within the orange-red circle being dead, and in many cases even perforated right through, owing to complete decomposition. These orange-red patches are the epiphyllous phase of this blight. EPIPHYLLOUS PHASE OF THE ALGA. 858. Asexual Reproduction. It is preferable to look for the spots mentioned after the monsoons have been fairly established, other- wise they may not be observed to suppport the filaments that give them their characteristic woolly and orange-red appearance. Later on in the season, they may be found to have changed colour and Tea Pests and Blights. 447 Blights on the Stem. become pale green, and in the hot months to have even assumed a grey colour. With the aid of a lens the filaments (examined, say, in June or July) will be found to support on their extremities, very minute rounded heads. These might be called the fruits. By the aid of the microscope they will be found to give origin to spores which eventually produce actively moving zoospores. These swim in the moisture of the leaf surface, or fall from leaf to leaf, more especially in the drip from avenue trees. In time they find a favourable position, become fixed, and each gives origin to a minute flat smooth little disk which, under the lens, will be seen to be very similar to the original orange-coloured patches, only that it does not possess a fringe of filamentous fruit-bearing bodies. This is the primary disk to which I have already alluded. For a time the primary disk remains in that condition, but in due course it may commence vigorous growth or die and disappear. Penetrating the epidermis of the leaf it forms the secondary disk which is placed between the cuticle and sub-epidermal layer of cells. The growth of this new disk raises the cuticle, which in time is perforated. The original disk disappears and the diseased spots of algal structure come, as it were, to be above the surface level of the leaf through the growth of the filaments of the secondary disk. 859. In other instances the primary disk may be itself parasitised by being attacked by a fungal filament. In consequence an entirely new structure is formed, the combined alga and fungus give origin to grey lichen patches that will be found dispersed all over the leaves upon which orange-red spots are numerous and fairly large in size. Every planter is familiar with the hoary colour of the older leaves of tea trees growing under shade. If such leaves be examined, three very distinct epiphytes will readily attract attention : (a) Orange-red woolly circular patches, raised up above the surface the alga here described. These will appear to be growing by a constantly widening rim, while dying in the centre of the patch. (i) Irregularly shaped patches of pale grey, more or less com- pletely coalescent and covering the surface of the leaf. Here and there this greyish white coating may be observed to support minute cup-shaped circular bodies either pure black or olive green in colour. These are WHITE BLIGHT. Round Heads -the Fruits. Spores and Zoospores. 'ormatlon of Disks. Secondary Disk. Maybe Parasitised. Hoary Leaves. The Alga. Lichens. 448 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. CEPHALEU- ROS VIRESCENS. Fungus. The Lichen and Fungus are Purely Epiphyllous. Penetrating Multicellular Filaments. CareftilStudy Necessary. SEXUAL R.PRODUC. the apothecia or fruiting organs of the lichens, the history of which has already been sufficiently indicated for the purpose of this report. (c) Brownish-black patches with radiating cobweb arms that seem often to cross the grey lichenoid formations. This is a fun- gus that is found in almost invariable association with the other two organisms. It is very possibly the species found by Prof. H. Marshall Ward in Ceylon and described by him in the Linnean Transactions Vol: II. (2nd Ser.) pp. 99-102. 860. Parasitic Action, The lichen and the fungus will readily be seen to be purely superficial and to have only a very slight attachment to the leaf. The alga, however, abstracts the sap of the leaf, as will at once be apparent from the circumstance already mentioned, namely, that the space within the actively growing circumference of the algal patch has been killed. It is, therefore, a parasite ; but as it invades the old and more or less useless leaves only, it might be regarded as a harmless parasite. Until the destruction has extended sufficiently far to cause an actual perforation, it will rarely be seen to have penetrated the entire thickness of the leaf. Unfortunately, however, Dr. Cunningham has shown that, on the leaves of a species of Cinnamomum, this alga no longer exists in the form of what might be designated an absorbent disk (or thallus) placed immediately below the epidermis, and which gradually sucks up the sap of the adjacent tissues, and in time no doubt kills them thus indirectly parasitic but that it produces, from its thallus penetrating multicellular filaments, dispersed through the thickness of the leaf, and is thus directly parasitic. In that case the spots are seen on both sides of the leaf, before any disintegration of the central space has been effected. I am not aware of its having been found in this more pronounced parasitic condition on the leaves of the tea plant. There is, however, very little reason why it should not so occur even if it be correct that it has not assumed on tea a directly parasitic form. We know even now far too little about this alga, and if progress in its eradication is to be looked for, greater attention will have to be paid to the comparatively harmless, though exceedingly plentiful epiphyllous phase, in its life cycle. 86 1. Sexual Reproduction, Before passing away from the epiphyl- lous condition of the blight, I desire to mention without describing more than very briefly, its sexual reproduction. The production o* Tea Pests and Blights. 449 Blights on the Stem. zoospores and the formation of the primary disk and subsequently of 'the sub-epidermal disk, with its crop of filamentous formations that burst through the epidermis and appear on the surface of the leaf, is an asexual reproduction. During the rainy months this is prose- cuted with vigour and numerous new patches are formed all over the host plant. But, as if in anticipation of the approach of rainless months and a dry hot atmosphere that would be fatal to most algae, this species, towards the end of the rains, takes steps to provide for its own safety. It produces, by special organs developed for that purpose on the disk, but underneath the epidermis, a hibernating fecundated or sexual spore (an Oospore as it is called) which, stored within the tissue of the old patch, rests until the return of the rainy weather. It then germinates, so to speak, and gives origin to zoospores in every respect similar to those already described, and which in time produce the disk with its asexual capsules. In this way, from fecundated germs or seeds, each year's crop of new epiphyllous patches may originate. THE CORTICAL PHASE OF THE ALGA. 862. Blanching of the Leaves. Turning how to the phase of the alga found on the stem. It has already been said that one of the symp- toms of this disease is a blanching of the leaves. This would not ap- pear to be an invariable occurrence, but it is sufficiently frequent to justify a strong suspicion of the presence of the alga when the white marbling already mentioned is met with. It seems probable that other conditions may induce the leaves to turn white, but this alga is undoubtedly the chief and most important cause". 863. When this blight occurs, if last year's shoots be examined, they will be found to be dry and discoloured and to bear on the bark, 2 or 3 inches below the point of origin of the lowest leaves, curiously livid blotches. If these be now examined, they will be found to give indica- tions of supporting some foreign organism, that is in vigorous growth on the periphery of the blotches. It may also be noted that these diseased patches have been deprived of the bark (or rather epidermis) that may be" recognised beyond their limitations, on the rest of the shoot. They thus seem sunk as it were within the tissue of the shoot. By holding the diseased twigs up between the eye and the light, it may be noted that, on the circumference of the patches more especially, a large quantity of minute drumstick-shaped orange-red filaments 29 RED-RUST. Oospores. DESTRUC- TION of TEA SfiiMS. Blanching of the Leaves. Con/. tHfh para. 832. Discovered on Last Year's Shoots. Irregularly Shaped Blotches Below the Surface. 'um Stick- shaped Orange-red Filaments 450 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. CEPHALEU- 80S VIRESCENS Debated Disintegra- tion of the Tissue. Depredations. Destruction of the Bark. protrude. These will at once recall the filaments with rounded heads already examined on the epiphyllous patches. Dr. D. D. Cunningham has in fact established that the condition here indicated is but a more deeply-seated form of the alga, in which as it continues to grow, the disk (or thallus) that supports these external fructifications is carried deeper and deeper into the tissue of the plant as each superficial layer becomes disintegrated. The bark of the shoots is thus removed by the growth of the alga, and the ascending sap being intercepted, the leaves gradually give indications of decreasing vigour until ulti- mately the shoot is killed. 864. DEPREDATIONS. The action of the alga in bringing about the death of the shoots, on which it occurs, will best be exemplified by now furnishing the passage from Dr. D. D. Cunningham's report of his investigations : " Specimens of the disease were forwarded to me for examination by Dr. King, of the Royal Botanic Garden, Shibpur, to whom they had been originally sent by the agents of a tea garden in which it had been the cause of considerable mischief. They consisted of branches bear- ing the remains of numerous withered leaves on their twigs. The terminal portions of the twigs where the bark was still young and green did not show any signs of disease, but lower down the surface was either covered by dense felts cf the fructifying filaments of Cepha- leuros or the bark was entirely wanting and the outer surface of the bast exposed to the air. Vertical and longitudinal sections of portions of shoots in various stages of disease unequivocally demonstrated that the destruction of the bark was owing to the disruptive effects produced by intrusive filaments, sheets and solid masses of the vegetative cells of the alga whose fructification clothed the surface in those places where any bark remained adherent. In the earlier stages of the disease the cortex was stil! of considerable thickness and the algal elements were situated comparatively superficially, spreading out in sheets through the corky strata and breaking up at intervals through it to give origin to erect, fertile filaments on the surface. In more advanced specimens processes could be seen descending through the substance of the host tissues from such superficial layers, and in their turn spreading out at deeper levels to give rise to new horizontally-disposed extensions which broke up the continuity of the surrounding parts, and in still older cases the thickness of the cortex was greatly reduced and algal Tea Pests and Blights. 45 Blights on the Stem. elements were visible throughout its entire depth right down to the outer limits of the bast. Taking these appearances into account, there can be no difficulty in accounting for the decortication and ultimate death of the affected shoots." " It is evident that the disease originates superficially, and is de- pendent on penetration of the outer layers of the cortex by processes descending from the under surfaces of the normal discoid expansions of Cephaleuros which are developed on any suitable surface on which the zoospores may happen to come to rest and germinate. Such pro- cesses find all the conditions for luxuriant growth in the constant water-supply and protection from direct exposure to the sun's rays which the cortical tissues provide. They grow freely and spreading out horizontally tend to break up the continuity of the tissues and to cause the desquamation of the layers which lie above them, partly by mere increase in bulk, and partly because they give off numberless emergent fructifying filaments which force their way outwards to the surface. At the same time they in their turn give off descending processes like those from which they originated, which force their way downwards into deeper portions of the cortex and give rise to new horizontal expansions. During periods of sunny weather and rela- tively low atmospheric humidity, the active growth of the algal elements will naturally be retarded, and, at the same time, the superficial layers of them and the disintegrated cortical tissues will tend to dry up and become detached, whilst the deeper strata of the host-tissues, which retain more continuity, persist and afford protection to the algal ele- ments which they contain. When, on the other hand, conditions of excessive humidity once more prevail, active growth will recur and provide for additional disintegration of the host-tissues, and these pro- cesses being recurrently carried on, complete destruction of the cortex will ultimately ensue, and the entophytic elements no longer meeting with a suitable nidus, will also disappear, leaving the bast-tissue com- pletely denuded." "The mere abnormal drain upon the water-supply of the host in- cident on the demands of the intrusive algal elements must necessarily tend to interfere with the nutrition of all distally situated parts even fromthe outset, and, with the advance towards complete decort.catior a purely physical evaporative drain must be established, the ultimate result of which will be a fatal defect in distal water-supply." 29 A WHN BLIGt Death of the Shoots. Produced from Zoospores. Effects of Formation of Fructifying Filaments. Latent Condition. Bast Tissue Denuded. 452 Report of Investigations in Assam Vegetable Parasites df the Tea Plant. CEPHALEU- VIRESC S ENS. Occurs in Damp Sites. Destruction Most Rapid with Exposure to the Sun. May be Con- veyed in a ^production influences that Induce he Zoospore;- of Epiphyl- lous Form tc Germinate 01 the Bark. 865. CONDITIONS FAVOURABLE TO THE GROWTH OF THE ALGA. Dr. Cunningham continues :- " The disease is described as tending to occur specially in particularly damp sites, which is just what might have been expected from its origin, seeing that excessive damp must, on the one hand, favour the vegetative growth, and on the other, the reproductive diffusion, of the alga. At the same time the destructive effects which it produces are likely to occur most rapidly and con- spicuously in sites which are freely exposed to the sun, and therefore at particular times of year subject to considerable desiccation, as this must both facilitate decortication and also render any abnormal drain on the water-supply of the host more injurious. Under the influence of excessive moisture, on the other hand, the extension of the entophyte within the host-tissues will occur rapidly, and fructifying filaments will appear in abundance on the surface of the diseased areas and produce innumerable sporangia, the zoosporic contents of which only require the presence of abundant moisture to become fully developed and endowed with active movement securing their diffusion. They will thus be able to spread from their site of development to other previously unaffected areas, and, on germinating, to serve as sources of infection there. Their diffusion, moreover, under the influence of excessive moisture will tend to be effected not only actively, but passively, as multitudes of them may readily be conveyed in any drop of water running along a continuous surface, or falling from a higher to a lower one. There is unequivocal evidence of this in the excessive prevalence of Cepha- leuros, which may constantly be found on the leaves of shrubs subject to drip from trees whose leaves are also affected by the alga." 866. DP, Cunningham does not publish any results of his examina- tion of the method of reproduction that prevails in the deep-seated or cortical manifestation of the alga, but, from the concluding sentence in the above passage, it may be assumed to be, in his opinion, brought about by zoospores in the manner which he has so fully exemplified in his admirable account of the species which was published (1880) in the Linnean Society's Transactions. There is, however, a practical consideration of the first magnitude to the tea-planting industry, that would seem still to await solution, viz., the circumstances that induce the zoospores of the epiphyllous condition to become fixed on the bark of the shoots, and to produce there the deep-seated and destruo Tea Pests and Blights. 453 Blights on the Stem. lively parasitic condition. That there must be some special condi- tions, as yet unknown, seems an unavoidable inference from the circumstance that, while no tea garden exists in Assam, in which the epiphyllous condition is not plentiful, the parasitic dangerous phase occurs within a curiously circumscribed area. I make this affirmation after having marched, from garden to garden, over the greater portion of the Assam Valley, and carefully noted the occurrence of the alga on the leaves. So very universally abundant is it that I have no hesitation in saying that it must also occur in the gardens not visitec by me. It is certainly more prevalent in gardens with avenue or shade trees (of a particular kind) and in those closely surrounded by jungle, than in the open. But I am prepared to say that, if taken to the middle of a district of many miles of uninterrupted tea, grown 01 the very best soils, in the absence of all the conditions that would seem to favour the growth of the alga, and with tea of any age or any jat I would have no hesitation in undertaking, within a radius of twentj yards around any spot selected at random, to point out bushes with the epiphyllous condition in abundance. The disease exists in every nursery of seedlings a year old, and from the nursery is carried to the garden, where it continues from year to year on the bushes. But though I gave the utmost care to this subject, I failed absolutely to find the alga on the bark of the shoots, except in the localities named. Moreover, I had bushes grown in tubs under observation and was unsuccessful in causing the epiphyllous zoospores to fix on the bark and produce the dangerous form of the blight. And I may also mention another circumstance of some interest, namely, that, while the epiphyllous conditions exist on a large assortment of bushes in the Assam jungles, I never came across an instance of the cortical form, except on the cultivated tea in the localities named. 867. REMEDY. That the blight described above as met with on the bark is a serious visitation, need hardly be stated. Once it gets established in a garden, its depredations are very alarming. It thins out the bush, branch after branch, and if the pernicious habit of burying the prunings prevails, it is distributed from bush to bush. Fungicides kill the fruiting structures that appear on the surface, but the actively destructive organism being buried within the tissue, is probably unaffected and is likely to continue to grow and to send out time after time countless tufts of its spore-bearing fructifications. RED-RUST. Universality Epipiiylluus Condition. The Cortical Form kestricted to a Few Localities. Yever Seen in the Jangle. Fungicides 454 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. Mr. Fleet who, during his short residence in Nowgong, started the investigation of this blight, wrote me on the Qth July, " Considerable cold water was at first thrown on my proposal to try fungicides. It is only now, that having proved my point in a small way, materials are being forwarded to allow of my experimenting further." " I have used various strengths of cuprie sulphate solutions, also the Bouillie Bordelaise fluid. I treated individual plants, selecting bad cases, and consider the result most encouraging. About 36 to 48 hours after application, the external or sporangia-bearing filaments were completely destroyed, and were no longer visible." " The bushes treated on i3th and i8th June have as yet protruded no further filaments." 868. If pruning be resorted to, the result is very nearly as disappoint- ing, since a stage must be reached below which pruning would mean the loss of any return for the season. Bushes must be allowed to carry the one and two year old wood on which the flushings are borne, and a certain percentage of the wood in that condition, within the area of this blight, will be at once invaded, and the process of destruction progresses apace with all efforts towards the eradication of the blight. In one garden, where this blight has assumed the position of being by far the most dangerous enemy of tea, cutting down shade trees, thorough drainage, and chemical manuring, have been carefully and systematically pursued. And along with these improvements by pruning out all affected parts, the blight has been to a certain extent kept under control, but it has by no means been eradicated. 869. From the foregoing remarks it may be gathered that I do not consider we are in a position to prescribe a fixed and satisfactory method of treatment. But it will be useful if I furnish here the concluding paragraph from Dr. Cunningham's recent and most valuable report : " In dealing with a blight of this kind, the great thing must necessarily be to prevent it establishing itself in sites presenting specially favourable conditions for the development of the alga. Cephaleuros occurs abundantly on most diverse hosts in tropical regions, but, as a rule, confines itself almost solely to leaves and pro- duces mere localised mischief in these. The affection of the leaves is, generally speaking, of no practical importance, but it may serve as a source of serious mischief where local conditions are such as to favour the excessive growth and multiplication of the algal elements Tea Pests and Blights. 455 Blights on the Stem. and their invasion of axial structures in which their presence may give rise to interference with the general water-supply of the host- tissues. The presence of the alga in and on leaves is readily recognisable from the conspicuous orange, lichenoid patches which the superficial discs and tufts of fructifying filaments form on the foliar surfaces, and the diffusion of the disease is a gradual process, and one which can never occur over wide areas with the rapidity with which that of many blights caused by the presence of parasitic fungi is effected. There can, therefore, be little difficulty in successfully contending with it at the outset, and by the careful removal and destruction of all conspicuously affected leaves when it first makes its appearance, and by avoiding planting in sites exposed to the drip from affected trees, any excessive extension of it, even within other- wise specially favourable localities, might be effectually prevented. Where this has been neglected, however, and it has been thus allowed to establish itself thoroughly and to invade large areas of bark, more drastic measures will be necessary in the form of free pruning or even total removal of entire shrubs and careful destruction of all the diseased tissues. The relatively slow growth and the limited means of diffusion of the alga are such that it can only be as the result of the neglect of such simple preventive measures that the disease can ever become of any serious importance in any locality, but, given the neglect, it may be the cause of very considerable mischief." 870. It will thus be seen that Dr. Cunningham gives the planters the assurance that " the diffusion of the disease is a gradual process, and one which can never occur with the rapidity with which that of many blights caused by the presence of parasitic fungi is effected." But observe that view is qualified by " the great thing must neces- sarily be to prevent it establishing itself in sites presenting specially favourable conditions " ; also by " the careful removal and destruc- tion of all conspicuously affected leaves when it first makes its appearance." Now, I believe I am correct when I say that, in no garden in Assam are the leaves affected with this blight collected and destroyed, not even in the districts liable to the form that invades the stem. It is not now a question of preventing the alga from be- coming established, but one of its eradication. I repeat it occurs in every garden in Assam, and very possibly upon 50 per cent, of all WHITE BLIGHT. Diffusion a Gradual Process. Removal of all Conspi- cuously Affected Leaves. voidance Destruction of all Diseased Parts. Given Neglect it may become a Causa of Considerable Mischief. Leaves never Collected ard Destroyed. I mportant Lessons. 456 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. the bushes in the valley. Under these circumstances the points of pressing urgency would seem to be as follows : (a) Has it been proved that the foliar condition can and will originate that on the stem ? () What are the conditions that favour or retard the transmission of the blight from the comparatively harmless to the posi- tively dangerous condition ? 871, Were these questions answered, we would be in a position to lay down definite rules to ward off a possible invasion of the entire lea area with this, one of the most destructive and most dangerous of all tea pests and blights. It was these considerations that led me a year ago to write, " Should, by any unforeseen circumstance, the germs that exist in every garden change from the one condition to the other, " Red -rust " would assume a truly alarming aspect, and it cannot be said this is an impossibility." (The Agricultural Ledger No. 2J of 1896:) 872. In the present state of knowledge regarding this blight, the following remedial measures seem worthy of consideration : / j/. Where shade trees are found to cause the leaves of tea under- neath to be coated with the grey lichenoid formations and the orange-red algal patches described above, the trees in question should be removed. 2nd. Where the leaves of any plot of tea are found to be abnor- mally attacked by the alga, they should be plucked off and destroyed, or washed with the fungicide already mentioned (p. 418). In neighbourhoods liable to the form that invades the stem, every orange- red-spotted leaf should be carefully removed and destroyed. 3rd. The seedlings in the nursery, if found to manifest the orange- red spots, should be washed with the above mentioned fungicide, and, in districts liable to the stem invasion, they should be dipped into a tub of that fluid at the time of transplantation, so as to ensure their freedom from any trace of the algal germs (see method described, page 39 2 )- 4th. In gardens where the stem invasion occurs, careful pruning should be pursued with the object of cutting out the blight. The diseased bushes should also be marked before pruning, so that they may receive special attention. All the prtmings should be instantly burned and the bushes copiously lime white-washed, in order to kill any trace of the germs of the disease that may be on the stem and branches Tea Pests and Blights. 457 Blights on the Stem. $th. In such gardens washing the shoots in Spring with the fungicide fluids, already mentioned, might be very beneficial. The washing perhaps had best be done with the hand, using a large mop. It seems probable that each year's attack originates from a hibernat- ing spore that is probably held mechanically on the bark. A good washing would very possibly secure the destruction of such spores. By being repeated later, on the disease first showing signs of its presence, no doubt a check would be thereby given to a wider distribu- tion. I would recommend comparative trials of one plot treated as directed in paragraph 4th above, the other with fungicide washings. 6th. With limited plots of tea badly infected, I should fire the entire plot in February or in March. For this purpose do not prune in December. The alga would appear to be inactive in winter, if so, it can do little further harm. I should, therefore, leave the bushes, as they are, till the time selected for firing. This would allow the disease time to settle into its hibernating condition, the invaded twigs would also become thoroughly dry, and the firing would accordingly be more thorough and effectual. After the bushes showed signs of partial recovery, I should light prune, where found necessary. If firing be thought too drastic a treatment, collar prune and at once burn all the prunings. It is useless to try first one cure, and then another, where the blight has got a firm hold of the bushes. Better sacrifice the yield of the plot in question, fora year or 18 months, and exterminate the blight, rather than incur the risk of its extending. The manager of one of the Nowgong gardens writes me that, in spite of all efforts to cut Out the blight, it is " increasing rapidly." If that be so, it is a mistake to experiment further with palliative treatment. Burning or collar pruning and washing the new shoots with fungi- cides, should they later on give indications of their being reinfested from neighbouring plots. By gradually adopting such treatment plot after plot, the blight would ultimately be got well in hand; severe measures are necessary for all badly affected plots. 873. It would seem that, were some such plan systematically pur- sued, in districts liable to the dangerous form of the blight, much pro- gress would be made towards eradication. In districts not so liable, every practicable effort should be made to prevent a concentration of the foliar phase of the blight, such as might be suspected to possibly favour the transformation into the second phase in the life of the RED-RUST. Washing wit Fungicides in Spring. 458 Report of Investigations in Assam Vegetable Parasites Of the Tea Plant. CEPHALEU- ROS VIRESCENS. Kaliden. Takes Two or Three Years to Kill the Bush Pale Shoots Should be Cut off. Salonah. Uprooting Recom- mended. Seeonee. Tezpur- Prunings Buried Found to Contain the Blight. . Might be Eradicated. Firing t the Preferable. species. The information we at present possess, justifies abundantly the statement that there can be nothing to gain, but possibly much to lose, by allowing the epidermal form of this alga to gain any further hold than it at present possesses on the tea bushes. Diary Notes on "Red Kust." 874. At Kaliden (visited i6th July), Red-rust was not very prevalent. It attacks the young shoots and kills downwards until it reaches the roots, but it takes two or three years to do so, the second, third and all sub- sequent shoots being killed each year. The leaves of the affected shoots turn whitish. It spreads rapidly by the prunings being buried. The first year a bush here and there, the second year more, and the third or fourth it may be all over the garden. The pale shoots appear about May, and these should be cut off even though the rest is not then visible. The shoots should be cut down to secure being below the rust. It attacks the last year's shoots (the young wood not cut off). At Salonah, visited lyth July, Red-rust was shown to me as the chief blight of the Nowgong District. Every garden has it, but Salonah per- haps the worst. It was first recognized in 1889 as a serious blight. Mr. Barry, of Kaliden, showed me the original correspondence which took place in 1889 between himself and Dr. King and Dr. Cunningham in which the fungus was determined as Mycoidea parasitica. It was then recommended that uprooting and burning was the only course. This has since, how- ever, been found impossible, as whole gardens are more or less affected. Pruning off the affected parts undoubtedly checks the disease, but so far no effectual remedy has been discovered. A very significant feature is the fact that it does not seem to spread very far beyond its initial area. At Seeonee (visited i8th July), Red-rust was found to be abundant and very destructive. At a garden in Tezpur District, visited July, the manager seemed amused at the idea of Red-rust being of any moment although it was fairly abundant and sapping the life out of many bushes. I remarked, that it was the most severely red-rust-blighted plot of tea land I had yet seen. I pointed out to him that it was the cause of the bushes being often half their natural size. Of their being now full of dead shoots, I picked up many prunings thai had been buried in the soil and found these covered with the rust. Hardly a bush near these rusted prunings had escaped the blight. There cannot be a doubt but that this disease is distri- buted and perpetuated by the pernicious habit of burying prunings I recommended that on no account should the prunings' of a rust-affected plot be buried whatever views might otherwise be held for or against that practice. I should think I am well within the mark when I affirm that at least 10 per cent, of the portion of the garden to which I refer was giving not more than half its natural yield. In fact, over large portions of the estate few bushes could be found that were not affected to some extent. With energetic action now, cutting off all dead shoots, as also all those clearly affected, and by burning the prunings at once, by heavy pruning in Autumn and burning the prunings also, and by white- washing completely the stumps, the disease might be stamped out, and the plot made one of the best in the garden. Sooner than allow these diseases to get established, I should set fire to the entire affected plot. Were this done in February, Tea Pests and Blights. 459 Blights on the Roots. the disease would be entirely eradicated, and the bushes flush again in two months' time. (Specimen No. 11978.) At another garden in Tezpur District, visited on the aoth July, I found Red-rust prevalent, but no mosquito a fact that somewhat agrees with the condition that prevails on the opposite side of the Brahmaputra at Nowgong. LXXII Fungi on the Roots of the Tea Plant. in. (a&c) Rosellinia sp. ( ? R. radiciperda, Massce), and possibly two other forms. ROOT FUNGI. References. Bamber, Chem. and Agri. Tea, pp. 256-25 ; Indian Forester, Vol. XIII. (1887), pp. 290, 388 ; Massee, Ke-vo Bulletin, 1896, pp. 7-5 ; Cunningham, Scientific Memoirs of Medical Officers of the Army of India Part III. (1887), pp. 8-n ; also Part X., pp. 22*24 ; Diseases of Plants, Karl Freiherr von Tubeuf, Trans- lated by W. G. Smith, 200-204 ; Text-Book, Diseases of Trees by R. Hartig, Translated by Somermlle and Marshall Ward, pp. 78-87. (Reg. No. 140 ; Botanical Specimens Nos. 11891, 9164, and 509.) 875. HISTORY. The subject of tea bushes being killed by fungi on the roots, has been mentioned repeatedly in the Indian technical news- papers, in the Journals, Agri.-Horticultural Society of India, and in the Indian Forester. Until investigated by Brigade-Surgeon-Lieute- nant-Colonel D. D. Cunningham, no progress was made. The first of Dr. Cunningham's papers, mentioned under the above paragraph of reference, gave the results of his examination of dried samples of roots that had been furnished to him. Unfortunately, since he had not the opportunity of examining fresh material, he could not procure culti- vations of the fungus, and was thus neither able to determine its position nor to assign a name to it. His second paper (an advance proof oi which has most obligingly been furnished me by the Director General Medical Department), reviews the state of our knowledge of the subject 876. During my brief explorations in Assam, I was led to think tha there might possibly be three root fungal parasites. The first one appears to originate saprophytically, and the second and third possibl) parasitically. It is a well-known fact that certain shade trees within the garden, if killed or felled, cause the death of a number of tea bushes around their stumps. The trees with this evil reputation, most fre quently mentioned, are the Sum (Machilus), Bokain (Melia), Mada\ (Erythrina), Simul (Bombax), indeed most soft-wooded trees Many of the tea bushes killed in this manner, which I dug up an 460 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. ROSELLINA Danger Burying Prunings. Con/, with para. 174. The Possible Parasitic Species. Stem Near the Ground Swollen. Cram Bark ibles to Circular Clump of Bushes Affected. Peculiar Con/, with paras. 882*3. examined, had a fine white mycelial thread, running along the outside and also penetrating to the interior of the roots, and a similar forma- tion was met with on the dead roots of the felled trees. It would in fact seem probable that the presence of any decomposing organic matter in the soil (primings or otherwise) may, when least expected, give origin to the fungus here indicated. 877. In the second parasite, the dead and dying bushes are found, perhaps remote from any shade trees and unconnected with any de- composing organic matter other than the tea bushes themselves. The leaves of diseased bushes are seen to gradually wither, to turn brown, and fall off without showing any fungal disease on their surfaces. This state of affairs very closely resembles the condition produced by grubs or wood-borers, only lhat in the insect-infested plants the leaves do not fall off the bushes, and death is, if anything, more gradual and local. If the stem near the ground of the fungal-infested bushes be examined, it will be found to be swollen, pulpy, and of a dark red colour. If the ground be uncovered, so as to reveal the roots, these will also be dis- covered to be irregularly swollen at interrupted positions. If the bark of the lower portion of the stem be examined, it will be found to crumble to pieces and to give indications of being diseased. There are no fungi to be seen externally, nor are the decomposed roots apparently penetrated by white mycelial cords, at least not such as are visible to the naked eye. It is clear, however, that a specific disease has been at work, and that it is readily communicative. Though starting originally with one bush, the infection gradually extends around, until a circular clump of bush may be dead or dying. This, so far as I am at present able to ascertain, was very possibly the disease examined by Dr. D. D. Cunningham mentioned above and from whose reports passages will be found below. 878. I have recently received from the Duars what I regard as a third fungal root parasite. In this white mycelial felted patches and cords are readily seen within and around the roots and in the inter- spaces of the soil adjacent to them. Complete decomposition of the bark and of the sap wood may also be noted to have taken place, leaving the heartwood as cord-like bands. At this stage orange- coloured irregularly-shaped patches may also be witnessed on the bark of the roots which are doubtless connected with the general decomposition. The condition that prevails in many respects agrees Tea Pests and Blights. 461 Blights on the Roots. with the root fungus Rosellinia radiciperda-which Mr. Massee has figured and described in the Kew Bulletin for 1896. The disease was stated to originate with one bush and to spread in a circular manner, the leives withering and falling to the ground as the roots became attacked. The bushes were thus rapidly killed. But it was remarked that it had uniformly appeared in Jabika seedlings three or four years old and had passed over intervening plots of Manipur stock. Several independent centres were observed and none of these in any way associatated with the death of trees subsequent to the original clearance of the forest. 879. It would thus seem desirable in future inquiries that the possibi- lity of two or more root fungi should be kept in view. As I had not sufficient time, while in Assam, to perform definite experiments, to ascertain the life histories of the root fungi, it will serve the purposes of the present report if I give here the results of DP. Cunningham's most recent investigations which, written by a mycologist of his experience, will be found a useful and suggestive contribution to wards a knowledge of this very obscure subject, but I may repeat that I regard the passages that follow as very possibly having reference to the fungus briefly indicated in paragraph 877 : " Specimens of this disease were sent to me for examination by Dr. King during the winter of the year 1887. As I have already published a note regarding the subject in Part III. of this periodical, * it is unnecessary here to do more than to give a brief recapitulation of the characteristic phenomena. The morbid changes were purely confined to the lower extremity of the stems and the bases of the larger roots, and presented themselves externally in the form of numerous, conspicuous, irregularly-nodulated swellings, which occurred so closely over the base of the stem and origins of the larger roots as to be more or less completely confluent, whilst farther out along the course of the roots they occurred in isolated patches. Where they were present, the bark no longer retained its normal smooth texture and grey colour, but was roughened, friable, and deep brown, owing to the mixture of earth, derived from the surrounding soil, with the disintegrated tissues. In certain sites masses of material of rusty-brown colour and spongy texture were visible in fissures of the surface, and, on removing portions of the disintegrating * Scientific Memoirs by Medical Officers of the Army of India. G. W. ROOT FUKGI. Dr. Cunning- ham's Report. Bark Roughened Friable and; 462 Report of Investigations in Assam Vegetable Parasites of the Tea Plant. ROSELLINIA SP. Rusty Brown Found to be Masses of Mycelia. Probable Method of Transmission bark, these were seen to form portions of sheets and strands of similarly coloured material traversing the tissues in every direction. Such material was present throughout the entire thickness of the cortical tissues, and specially abundant at the level of the bast, where it was in many places spread out so as to form a continuous stratum over large areas. The wood appeared to be comparatively little affected, but was here and there interrupted by distinct wedge-shaped portions of a greyish tissue, with narrow, sinuous, blackish margins." " On microscopic examination, the rusty brown substance was found to be composed of dense, felted masses of mycelial filaments of brownish or greenish colour, and in those areas in which the invasion of the disease was progressing, but in which the tissues still retained their continuity, the cortex and bast were found to be everywhere permeated by fine filaments forcing their way between the constituent elements. In the earlier stages of disease, the wood appeared to be entirely unaffected, but, where it was far advanced, the mycelium tended to invade the medullary rays and to give rise to the dis- coloured radii previously alluded to." "All attempts at cultivating the mycelium with the view of obtaining fructification failed entirely, which is hardly to be wondered at considering that it had evidently been primarily developed parasitically in connection with the living elements of the tissues, and that, by the time the specimens were submitted to examination, the latter were already dead and dried up. A certain amount of growth did occur in some cases, but it was soon arrested and was never attended by the production of any distinct reproductive bodies. The pheno- mena apparently indicated that the persistent masses of mycelium contained a certain amount of intrinsic nutritive material stored up within them which served to provide for a limited amount of growth, but that, when this had been expended, the latter ceased in the absence of any living host-tissues as a source of further supply. In those cases in which such limited growth occurred, the outer surfaces of the bark became covered by a coating of an orange colour, consisting of short, erect, emergent filaments originating from newly- developed horizontal extensions of mycelium within the substance of the tissues. The development of such emergent filaments in this case is probably an indication of the method in which the extension of the parasite from the roots of one plant to another is affected. The Tea Pests and Blights. 463 Blights on the Roots. growth which occurred in the present instance was, no doubt, very limited and only sufficient to give rise to a superficial coating of mycelium on the diseased tissues, but under normal conditions, where the mycelium is in full vigour and the host-tissues still capable of affording abundant nutritive supply, it may well be much more extensive and provide for the development of mycelial strands capable of traversing considerable areas of the soil and so of coming into con- tact with neighbouring healthy roots." "As the specimens neither contained nor yielded anything save masses of purely mycelial elements, it is impossible to come to any definite conclusion in regard to the precise nature of the parasite, but taking the characters of the disease into account along with the well-ascertained fact of the destructive form of root- blight which prevails in European coniferous forests in connection with the invasion of the tissues by the mycelium of Agaricus melleus, Vahl., it appears not improbable that it may be of HYMENOMYCETE origin." 880. REMEDY. " Fortunately, however, there can be no doubt in regard to the nature of the measures which ought to be adopted in order to limit the extension of the disease in any area within which it has established itself. All diseased plants ought to be at once removed and burned, and special care should be taken to remove the roots as thoroughly as possible, so that portions of them may not remain in the soil as sources of infection. If possible, more- over, it would be desirable not to replant the infected area for some time, and also to isolate it by means of digging a trench around it sufficiently deep to pass below the lowest level in the soil to which the roots normally penetrate. By such means any extension of mycelium connected with residual fragments of roots remaining in the soil to neighbouring uninfected areas would be effectually prevented, and in the absence of suitable nutritive sup- ply the parasitic elements would, in the course of time, die out within the primarily infected one." 88 1. One or two dressings with lime, deep hoed into the soil would no doubt hasten the decomposition of the fungus. As a rule where root-fungi appear spontaneously, that is to say, in the absence of any evidence of communication from the roots of other trees, the soil will be found to be of a heavy black clayey mould that would be OOT FUNGI, Disease Coniferous Forests. Hymenomy- cete. Bushes Should be Removed and Burned. Con/. wUh para. 884. Affected Areas Should not be Re- planted for Some Time. Lime. Report of Investigations in Assam Vegetable Parasites of the Tea Plant. EOSELLINIA Duars Root Fungus. Con/, with para. 878. Pyrenomy- cete. Pourridie. improved both by lime and deep sub-soil drainage. It would seem probable that such defects may act as predisposing conditions to an infestation of root fungi. The presence in a soil of an excessive amount of organic matter, more especially imperfectly decomposed animal or vegetable matter, must prove a source of constant danger, and consequently the oxidation of the soil by drainage becomes an imperative obligation. 882. Since the above account of the probable three forms of root fungi found on the tea plant, had passed into final page proof, before Mr. George Massee's report on the form briefly indicated (paragraph 878) had reached India, I have thought it preferable to leave the account of these blights as originally prepared by me and to add the additional information, now brought to light, as supplementary. In my letter to Mr. W. T. Thiselton Dyer, Direc- tor, Royal Gardens, Kew, (nth November 1897), which forwarded samples of the diseased roots just then to hand from the Duars, I pointed out that it seemed to differ from the root fungi found by me in Assam (paragraph 77) in the peculiarities already briefly indi- cated. Mr. Massee's report sent in reply may be here given : " The fungus surrounding the root and base of the stem is some PYRENOMYCETE ; sporangia are abundant, but unfortunately old and empty, consequently the name cannot be determined with certainty. It is very closely allied to Rosellinia radiciperda, Massee, and may prove to be identical with that species. The necessary measures for dealing with ' root fungi ' are given in detail in the Kew Bulletin, 1896, pages 1-5." 883. The paper in the Kew Bulletin, to which Mr. Massee alludes, is one of great interest to planters, and I commend it to their careful consideration ; but I may be permitted the remark that it is very signi- ficant a fungal blight on the roots of trees in New Zealand should occur (or some closely allied fungus) on the roots of the tea plant in India. The following passages from the scientific part of Mr. Massee's paper may be accepted as a sufficient introduction to his remarks on " Preven- tive Measures" which 1 make no apology for reproducing in full : " Amongst the numerous root diseases of various plants caused by parasitic fungi, none are better known, or extending over a greater area than the Pourridie, of the French, which occurs in Tea Pests and Blights. 465 Blights on the Roots. France, Italy, Switzerland, Austria, South-West Germany, and has recently been recorded from three widely separated localities in Britain. The fungus causing this disease is called Dematophora necatrix, Hartig, which frequently devastates vineyards and orchards ; its attacks, however, are unfortunately not confined to vines and fruit trees ; potatoes, beans, beet, etc., are also destroyed, and Hartig states that the mycelium soon kills young maples, oaks, beeches, pines, and spruces." " Dematophora necatrix is almost entirely confined to heavy clay soils, where the water drains away with difficulty, whereas Dematophora glomerata, Viala, an allied, but much rarer fun- gus, with a similar destructive habit, hitherto observed only in France, is met with attacking plants growing in loose sandy soil, where the sub-soil is wet." "During the spring of the present year, a sample of soil was received by the Royal Horticultural Society from Mr. Hooper, Cam- bridge, Waikato, New Zealand, containing roots of apple trees attacked by a fungus, with a communication stating that the roots of fruit trees which penetrated the places where the fungus appeared to reside became infected, the fungus penetrating the tree and ultimately killing it. This material was forwarded to Kew for investigation. Sterile mycelium alone was present, which appeared to agree in every detail with that of Dematophora necatrix, and the fungus was provisionally referred to that species in a brief report published in the Journal of the Royal Horticultural Society (xix., part /., *?). The following account will give an idea of the injury caused by this fungus, as observed by Mr. R. Allen Wight, of Auckland, New Zealand *: ' This fungus, in the mycelial stage, attacks a great variety of tree roots, # Journ. Mycol., Vol. V., p. 199- ROOT FUNGI. 4 66 Eeport of Investigations in Assam Vegetable Parasites of the Tea Plant. ROSELLINIA Whole crops of potatoes are destroyed on such lands, and on dry lands where native tree stumps remain it is very prevalent. My own opinion is that it is a fungus native to, and probably peculiar to, New Zealand (in the North Island only). All my experiments with sulphur and lime have failed. Kerosine oil used in winter has alone been of any use, and that has been used pure in winter without killing the trees. The fungi of New Zealand are legion, and very destructive, but this is the worst, and par- ticularly as it is confined to dry soils. Where I am now writing 500 trees have been killed within the last two years, and all remedies tried have failed. The apple scab, the short-hole fungus, the Oidium of the vine are terrible pests in New Zealand, and the settlers have more to fear from fungus growths than insect pests."' " As previously stated, the material received from New Zealand was, in the first instance, referred to Dematophora necatrix. Further development of the fungus, and the receipt of additional fruiting specimens from the same country, showed that this was a mistake, neither does the fungus belong to any known species. It will, therefore, be described as new, under the name Rosellinia radiciperda," " Preventive Measures. " 884. " Notwithstanding the fact that the New Zealand fungus proves to be distinct from the European root fungus, yet the general habit, mode of attack, and structure of the two are so similar, that the same methods of combating the disease will apply to both." " Owing to the habit of the fungus in penetrating and spread- ing in the living tissues of the root of its victim, cure is practically outside the question when a plant is once permeated with mycelium ; and keeping in view the varied modes of reproduction for facilitating the rapid spread of the disease, no efforts should be spared in the way of preventing such spreading, when the presence of the fungus is once detected." " Undoubtedly the most frequent and rapid mode of spreading is by means of the mycelium travelling in the soil, and a good method of isolating diseased patches is to cut a narrow trench, from nine inches to a foot deep round such, care being taken to throw the excavated soil into the diseased portion, and not outside it. This method, which was first suggested by Hartig, for the purpose of preventing the spread of subterranean fungi in the German forests, cannot be too strongly commended, especially where the diseased patches are small in area. The amount of success depends entirely on the thoroughness, combined with an intelligent method of carry- Tea Pests and Blights. 467 Blights on the Roots. ing out the w&rk. Half attempts invariably result in a loss of capital without benefit. It may be enough to suggest that the disease may be spread by the spores of the fungus, or infected soil being carried by the shoes of labourers, by dirty tools, wheels of carts, animals, etc., from diseased centres. Diseased and fallen trees, and especially stumps and roots, should be at once destroyed by burning, The soil surrounding diseased stumps should be burned after the stumps have been removed, so as to destroy the smaller diseased portions of the root that remained behind. " " A second preventive method, which has proved of service in France, is to lay bare the trunk as far below the surface of the soil as can be done without injury to the tree, and to densely coat the exposed trunk and adjoining soil with powdered sulphur. This should be repeated when the channel round the trunk becomes filled up with earth. If, as stated by Mr. Wight, the New Zealand fungus first attacks the trunk just below the surface of the soil, this method should prove beneficial if persevered with." " Stagnant water should not be allowed to remain in the soil, as this favours the spread of the fungus." " Finally, in those cases where the fungus has completely devas- tated large areas, it is probable that such will 6e deserted as unprofit- able, the trees being allowed to lie and rot, and the fungus to spread in the soil. This is disastrous, being in fact a nursery for the development and diffusion of the enemy. It is not the object of this note to suggest whose business it is to prevent such short sighted- ness, but to impress emphatically that such a condition of things should not be tolerated. " ROOT FUNGI. INDEX. Also Glossary of the more Common Terms. Abandoned Tea, 133. Abbay, Rev. Mr., 21. Abies trees, 465. Abrasion, External, 356. Absorption, 67. Acacia arabtca (babul), 173. Acacia dealbata, 166. Acanthopsyche bipars, 210. A. moorei, 213. A. plagiophleps, 211. A. reidi, 211-12, 215, 217. A. rhabdophora, 211. A. snelleni, 213-14. A. sp.?, 214. A. sp. 7 214. A. subteralbata, 21 1, 214-15. Acarinse, 372408. Acarus cotfeae, 27. A. sp., 393400. A. translucens, 393. Achras Sapota, 435. Acridise, 260. Acridium flavicorne, 260. A. peregrinum, 260. Adhatoda Vasica, i, 1012, 167, 292, 293, [ 296, 308, 361, 386, 387. 392, 4o8. Adulteration of seed, 42. Affinity, 37,66, 71, 316. Agaricus melleus, 463. Age, Effects of, 18, 19, 104, 121. Agricultural Improvements, 52. Agricultural Ledger, 363, 3 66 > 4, 45- Agri.-Horti. Soc., 58, 59, 97; 99. i79> I 8o > 181, 187, 194, 196,202,207,209,213, 215,220,238,261, 264, 265, 301, 302, 303, 3 . 3ii 32i, 323, 325, 340, 362, 37, 373. 419. 433. 434. 459- " Agriculturist, Indian, 351. Agromyla, 255. Agromyza, 255. Agrotis segetum, 27. A. suffusa, 27, 262. A. ypsilon 240-41, 262. Air, 33. 36. 56-57. 66, 68, 70. 168,41* Albizzia stipulata (the Sau tree), 5- 52, 64. [ 169,171-72.176,290.446. Alder (Alnus glutinosa), 171, 235- Aleurodidse, 328. . _ Alexander, Mr. J. Lindsay, 65 ; on P n ' n ?' 118-19, 120 ; collar-pruning, 126, 283. 288, 294, 295, 296, 307. 3H. 36L 407. Aleyboom', Dr.'c., 264. 267, 280. Alga; (-mostly aquatic " Alitrunk," 258. Aloes, 363. Alston, Mr., 193, 293. Amatissa consorta, 204, 205, 206, 207 10, C 215, 323 Amguri, 4, 192, 199, 292, 397, 425, 441. Amluckie, 7, 442, Ammonia, 34, 37, 56, 65, 69, 163, 168. Anderson, Dr. A. R.S., 180, 191, 214, 237. Anderson, Dr, Thomas, 265, 266, 271. Andraca bipunctata, 19698, 219, 232, [248. Animal Pests, 370-71. Annual crops, 18. Ant, Red, see CEcophylla smaragdina. Ant, Red-black, see Cremastogaster con- [ tenta. Antennae (= feelers of a moth or butterfly), [ 195. 332, 337- Ant-hills, 341. Anthocephaluscadamba, 373. Ants, see Hymenoptera, 319. Aphida;, 311-16. Aphides, see Hemiptera. Aphis, Black, 27. Aphis coffea;, 27. Aphis, lion, 315. Aphis, Tea, see Ceylonia theaecola. Apology for Bad Gardens, 19-20. Apple trees, 465. Apple-foliage blight, 23, 314. 393~ 4>. Acrachnoidea, 370, 372-408. Araucaria, 353. Archipelago, 268. Arctia ricini, 238. Arctiidae, 230, 238-39. t Arhar dal, see Cajanus mdicus. Arsenical Preparations, 10, 284, 309. Asafoetida, 363. Ashes, 96, 161, 163, 165, 310. Asiatic Society's Journal, 213. Aspidiotus camellia?, 321-22, 323, 399 A. cyanophylli, 321. A. dictyospermi, 323-24. A. flavescens, 321, 322, 3 2 3- A. latanise, 321. A. orientalis, 334- A. these, 321. 322-23. 326. A. transparens, 321. A. trilobitiformis, 323. Assam, Districts visited, 3-7- Assam, Gazette, 274- Assam Indigenous, see Stock. Assam Scale Louse, 324. Asterina, 265. INDEX. Astycus chrysochlorus, 191, 192. A. lateralis, 191, 192. A. sp., 192, 194. Atkhel, 3, 4, 251, 292, 397, 398. Atkinson, Mr. E. T., 264, 270, 273, 276, 295, [323- Atmosphere, see Air. Attack, Particular Jats, 25. Attaree Khat, Tea Co., 350. Australian Lady-bird, see Vedalia cardina- [lis. Averages, Value of, 18. Babbu Pass, 3. Babul, see Acacia arabica. Babula grotei, 213. Babula sp., 213. Bacterium (=a unicellular fungal organism), [ 168, 169, 170, 173, 174- Bacterium radicicola, 169. Bacteroid, 170. Badulipar, 4, 232, 293, 307, 426. Bag-worms, 201-2, 204 6. Baijnath, 3. Baildon, Mr. ; on Drainage, 74 ; on Shape of Bush, 113; on Plucking, 149, 197, 261,373,419- Bait for fishing, 206. Bajaora, 3. Baker, Dr. R. A., 202. Baker, Mr., on Drainage, 74. Balaghat, 355. Bali j an, 6. Balmer, Lawrie & Co., Messrs., 191,209, 351, [366. Bamber, Mr. ; on Hoeing, 60-61; on Drain- age, 75, 81, 83, 90, 92 ; on Burying of Prunings, 94-95 ; on Shape of Bush, 113; on Collar. pruning, 123; on Pluck- ing* !39> JSo-S 1 > on Effect of Legu- minous Crops, 176 ; 183, 186, 189, 196, 199, 202, 205, 213, 218, 219, 224, 232, 236,240,243,255, 261,264, 33 309. 311,321,325,330,361,373, 377, 383, 433 459- Bamboo, 5, 52. Bamon Pukri, 3. Banjhi (=barren), 30, 49, 117, 132, 184, 306, [ 3I3. 399. 436. Bark, 37, 214, 384. Bark-bound, 313. Bark-eating Caterpillars, 204, 206, 209, 210, [ 211, 214, 231, 237, 253. Barlow, Mr. Edward, 180, 192, 224, 249. Baroda, 239. Barota, see Amatissaconsorta. Barry, Mr. N., 297. Barry, Mr. S. M., 231, 458. Basket-worm, see Amatissa consorta. Bateabandapuk,see Amatissa consorta. Baraloni seed, 30, 50. Beans, 465. Beddome, Colonel H., 370. Beech, 235, 465. Bees, see Hymenoptera, 319. Beet, 465. Beetles, see Coleoptera. Begg, Dunlop & Co., Messrs., 303. Begg, Mr. J., 198. Belippa lohor, 22426. B. laleana, 226. Bentinck, Lord W., 42. Bergroth, Dr., 273. Berkeley, Rev. Mr., 21, 265, 434- Bidie,Dr. G., 217. Biswanath (Bishnath) 7, 223, 232, 282, 420. Black Aphis, 27. Black-Hairy Caterpillar, 237. Black Bug, see Ceylonia thesecola. Black Bug, see Lecanium nigrum. Black Caterpillar, 231. Black Fly, see Ceylonia thesecola. Black Fungi, 27, 266, 319, 327, 332,433- Black Grub, see Agrotis ypsilon. Black-Hairy Caterpillar, see Creatonotus [ lactineus. Black Rust, 265. Black Smut, 265. Black Wasp, 315. Blandford, Mr. W. F. H., 193, 228, 235. Bleeding, 39. Blending leaf, 46. Blight, see Helopeltis. Blight, Grey, see Pestalozzia Guepini. Blighted Gardens, 19, 22. Blights (=vegetable parasites), 20 25, 178, [ 1 80, 261, 409463. Blights and Pests, Increase of (see also Pre- disposition), 1 6, 19, 90, 92, 95, 157, 158, 164, 465- Blights, Brown, on the Leaves, 42 8 433. Blights on Stem, 43359- Blights on the roots, 25967. Blights proof stock, 31,42. Blister Blight, see Exobasidium vexans. Blistering, Sun, 71, 391. Blister-mite, 23, 404. Blumea, 65. Bokain, see Melia. Bombax, 459. Bombyces, 230, 253. Bombycidse, 196198. Bone-dust Ash, 162, 166. Bordeobam, 7, 398, 442. Borer, Leaf, see Ocinis theae. Borjuli, 7, Bor Phukri, 7, 387, 407. Borsillah, 196,252. Botanical characteristics, 14. Botanical investigation, 3. Bouillie Bordelaise, 418, 454. Brachytrypes achatinus, 261 63. Brahmaputra Kiver, 196, 296, 330, 459. Branches, Age of, 120, 125, 131. INDEX. Branches or Twigs, Crows' footed, 120, 129, Branches, Formation of, 97, 105-6, 113, 117, [ 126, 131. Brown blight, 23, 51, 428433. Brown Bug, see Lecanium coffeae. Brown Caterpillar, see Andraca. Bruce, Mr., 17. Bukhain, 446. Buckingham, Mr., 171-72, 176, 192, 199, [ 292. Buckton, Mr. G. B., 311. Bud, Central in Seedlings, 115, 116. Bud-involving, Tortrix, 249. Buds, Accessary, 109, 135, 156. Buds, Development of Hastened, 140, 150, C 151- Buds, Fixed positions of, 14245. Buds, Lateral, 103, 106, 115, 132, 13445. Buds, Presence of on Stem, 122. Buds, Pruning in Relation to, 103. Buds, Retained after Plucking, 135, 145. Buds, Starved, 103. Bug, Tea, 264. Bug, Black, see Ceylonia theaecola. Bug, Black, see Lecanium nigrum. Bug, Brown, see Lecanium coffeae. Bug, Green, see Lecanium viride. Bunch Caterpillar, see Andraca. Burma, Tea in, 218, 410. Burning, see Firing. Burying weeds, 185. Bush, Character of, 25, 105-6, 131. Bush, Pyramidal, 98, 106, 113, 130. Bush, Shape of, 14, 98, 105-6, 112 14, 128, t 141- Bushes, Broom-like, 98. Bushes, Dwarf, 98, 106, 109-10, 114. Bushes, Interlining of, 91. Bushes, Large versus Small, no, 114, 128. Bushes, Low open, see Bushes, Dwarf. Bushes near drains, 84. Bushes, Over-crowding, 92. Bushes rising out of ground, 86-87, 122. Bushes, Rows of (their direction, distance, [etc.), 78, 80,91. Bushes, Size of, 52, 98, no, 114, 128. Bushes, Standard, 106, no. Bushes subsiding, 87. Bushes, Table-shaped, 98. Bushes Thinned out, 98. Bushes, Unhealthy, 19 (causes of), 92, 105, [ 134- Bushes, Uprooting of, 18, 20, 40, 47'4 8 8o > 92, 120, 128, 130, 158, 160, 322, 412. Butterfly, see Lepidoptera, 195. Cabbages, 42, 465. Cacao, 269. Cachar, 168, 186, 191, 192, 204,218,262,265, "268, 287, 297, 302, 303, 304, 311, 351, _ , 370372,373.377.38i, 4i3.4i9 420,434. Cachar stock, 15, 30, 191, 202, 204, 206. Caesalpinieae = sub-order of Leguminosa?, (which see) represented by the Cassia, Caesalpinia, etc., 173. Cajanus indicus, 320, 356. Caking, see Soil. Calicum, see Lime. California, 167. Camellia, Flowering, 27, 328, 413, 433. Camellia thea, 26 Capillary attraction, 37, 66, 69, 71. Capnodium Footi, 327, 433. Capsidae, 264302. Capua menciana, 248. Carbolic Powder, 316. Carbon, Absorption of, 34, 37, 57, 163. Carbon bisulphide, 186. Carbonic Acid, 34, 36, 56, 69, 162. Cardamomum, 290. Carteria decorella, 337. Catantops indicus, 260. Caterpillar (=larva of moth or butterfly), 195. Caterpillar, see Andraca. Caterpillar, Bark-eating, 204, 206, 209, 210, [ 211,214,231,237. Caterpillar, Black, 231. Caterpillar, Black-Hairy, 237. Caterpillar, Black Hairy, see Creatonotus [ lactineus. Caterpillar, Brown, see Andraca. Caterpillar, Bunch, see Andraca. Caterpillar, Daily Collection of, 197-98, 238. Caterpillar, Green, see Chaerocampa. Caterpillar, Hairy, see Lasiocampidae. Caterpillar, Hairy, see Lymantriidae. Caterpillar, Hairy Poisonous, 230, 231. Caterpillar, House-forming, see Amatissa [ Consorta. Caterpillar known as bhalu pok, 239. Caterpillar known as Katra, 239. Caterpillar, Lappet, 228-29. Caterpillar, Limpet, see Acanthopsychereidi. Caterpillar, Lobster, see Stauropus. Caterpillar, Looper, 231, 241. Caterpillar, Night feeding, 197, 233. Caterpillar, Quantity collected, 198, 238. Caterpillar, Sandwich, 246, 249252, 441- Caterpillar, Stinging, Slug-like, see Limaco- [ didae. Caterpillar, Urticating Slug-like, 226228. Caterpillar, Wood -boring, 21720. Cattle Flies, see Diptera. Causation of Blights, etc., 25. Cedrela, 279, 290. Cells (=ultimatic structures of plants), 35- [ 36, 37 38, 39- Cellulose (=starch of which wood is com- [ posed), 37. Census of Mosquito, 283. Cephaleuros virescens, 23, 95. 231, 431, 433. I 442, 443459- INDEX. Cephaleuros mycoidea, see C. virescens. Ceroplastes ceriferus, 319, 320, 336. C. floridensis, 336-37. C. myricae, 331, 333-33" Cess-pools, 81, 88. Ceylon, Pests of, 20, 21, 27, 28, 181, 1.92, 196, 199,201,211,215,218,240, 243, 255, 257,259,268,269,270,271, 287, 311, 3*2, 3*5, 3*7,320, 321, 322, 327, 332, 336, 372, 388, 393, 394. 395. 399, 413, 445- Ceylonia theaecola, 27, 190, 201, 258, 264, [303.31116,398. Chaerocampa alecto, 198. Changes in plant, 55. Chaukidingi, 6. Charali, 296, 308. Chemical changes, 34. Chenga Tea Co., 268. Cherideo, 3, 290, 313, 314. Cherry, 186. China, see Stock. Chinese wax insect, see Ericerus pel a. Chionaspis biclavis, 325, 326-27, 412. C. exercitata, 325. C. prunicola, 327. C. these, 266, 325-26, 327. Chiswick Soap, 10, 386. Chittagong, 73, 214, 261, 349. Chlorita flavescens, 10, 12, 13, 48, 191, 264, 272,30210,337,374,401, 404, 405, 412,427. Chlorophyll (-green colouring matter of plants), 34, 36. Christison, Mr., on Plucking, 15356, 265, [ 373, 382, 384, 385, 386, 433- Chrysalis (pi. Chrysalides,=the resting stage of a moth or butterfly), 182, 195, 331. Cinchona, 257, 266, 269, 273. Cinchona succirubra, 266. Cinnamara, 4. Circulation, see Sap. Citrus, 412. Clania crameri, 202 4, 206. C. holmesi, 2067. C. variegata, 202, 203, 2046, 208. Clay, Absorption of, 67. Clay, Caking of, 60 Clay, Chemical Changes of, 163. Clayey loams, see Soils. Clearances, New, 19-20, 78, 159. Cleghorn, Mr., 340, 343, 353. Climatic Changes, 17, 33, 133, Closed Gardens, 20. Clover, see Trifolium, Coccidae, 266, 316337. Coccus cacti, 319. Cochineal insect, see Coccus cacti. Cockchafer, see Lachnosterna impressa. Cocoon (=the outer covering sometimes formed around a chrysalis), 198. Cocoons buried under ground, 225. Coffea bengalensis, 26, 257. Coffee-bug, 329. Coffee-bug, see Lecanium Coffeae. Coffee, Diseases of Ceylon, see Hemileia [ vestatrix. Coffee Plant, 26. Coffea travancorensis, 21. Cold soils, 88. Coleoptera (=beetles), 182194. Collar, see Pruning. Collar, True, 121-22. Collection of Musquitos, 283. Collection of Pests, 195. Collections made, 2. Colour of Assam jat, 29. Congou, 139, 146. Consequences of Diseases, 14, 355. Constitutional Disease, 409. Coonor, 318. Co-operation of planters, 8, 13, 180. Copper, Sulphate of, 418. Copris beetle, 184, 194. Cossidae, 217 20. Cossipore, Cachar, 186, 218, 302. Cotes, Mr. E. C., 28, 29, 179, 181, 183, 186, 187, 189, 191, 196, 197, 199, 203, 204, 205, 208, 210, 213, 218, 222, 223, 224, 231, 232, 233, 235, 238, 240, 241, 242, 243, 248, 253, 255, 260, 261, 270, 303, 34, 3 5,3i, 3 1 *, 312, 321, 322, 3 2 5 326, 327. 330, 340, 373, 375, 377, 3?8, 383, 384, 385. Cotyledons (=seed leaves), 121. Cow-dung as an insecticide, n. Cows, 370. Crabs, 75, 370. Creatonotus emittens, 239. C. lactineus, 239. Cremastogaster contenta, 257-59, 315, [3i9- C. dohrni, 257, 319, 320, 333. Crickets, 240, 260, 261-63. Cricula trifenestrata, 195. Crinkly Blight, see Chlorita flavescens. Crioceris impressa, 194. Cripps, Mr., 164. Crole, Mr., on Drainage, 75; on Burying of Prunings, 95, Collar-pruning, 125 ; Banjhi, 133; Plucking, 151, 183, 261, 265, 286, 303, 304. Cross, see Hybrid. Crotalaria striata, 177. Crows-foot Clumps, see Branches. Culbard, Mr., 53. Cultivating, 269. Cultivation, Effects of, 14, 25, 26, 30, 55, 61, } 92,97, 99, 105, iii, 178, 181. Cultivation, Nature of, 72, 131, 269. Cultivation, Reforms in, 159. Cultivation of seed gardens, 51. Cunningham, Dr. D. D., 179, 340, 434, 435, 436, 439, 443, 445, 448, 45, 452 454,455,458,459,46o. Curculio tanymecus, 194. Cure, 1 8, 32, 286,289, Cushion Scale, see Icerya segyptiacum. INDEX. Cuttings, Propagation by, 122. Cut-worms, see Agrotis. Cycad, 334. Daddy Longlegs, see Diptera. Dactylopius destructor, 317, 319. Dalbergia assamica (Medeloa), 173, 177. D. stipulacea, 177. D. volubilis, 177. Dallas, Mr., 343. Darjeeling, 183, 187, 199, 210, 218, 232, 237, 239,265, 268,, 271, 273,278, 289, 304, 3053H 321, 323 336, 370, 373' 38i, 383. 420, 434, 445. " Darjeeling News, The," 303, 383. Darjeeling, Notes on, 61, 74, 149, 183, 185, 187, 189, 196, 199, 202, 205, 208, 209, 237, 261, 264, 303, 305, 328, 373. 381- Darjeeling Scaly-bugs, see Eriochiton nov. [ sp. Darjeeling Tea Co., British, 327. Darrang, 221. " Dash," 56. Dasychira hornsfieldi, 237. D. (Olene) mendosa, 232-35, 236, 238, [293- D. pudibunda, 235. D. securis, 236. D. sp., 235-36. D. sp., 236, 237- D. thwaitesi, 236. Davies, Mr., 362. Death-rate from collar-pruning, 124. Decomposition of Soil, see Soil. Deep cultivation, 53. Defoliated Bushes, 197, 205, 209, 221, 236, [ 239, 260, 432. Uehra Dun, 241. Dekamali gum, see Gardenia gummifera. Dekho, 3. Dematophora glomerata, 465. Dematophora necatrix, 465. Dempsey, Mr., 85. Deopam, 3. Depreciation, see Deterioration. Depazea, 433. Desmodium gangeticum, 167. D. polycarpum, 177. Deterioration, Indications of, 832, 19, 74, [ 104, 121, 155-60. Davenport & Co., Messrs., 183, 321, 327. Dharmgiri, 3. Dholebagan, 3. Diapromorpha melanopus, 18691. Diaspinse, 320. Diastase, 35. Dibrugarh, 6, 12, 23, 27, 130, 171, 213, 218, 232, 249, 252, 271, 282, 293, 294, 307, 394, 398, 399, 412, 413. 4i6, 420, 421, 426, 427, 430, 441, 442, 444- Digestion, 34, 37, I54 . Dillema mdica, 435, 439. Dimapur, 4. Diptera, 255257. Dirpai, 7 192, 296,308, 314, 331, 333, 427. Disease, Origin of, 16-17, 55, 131, 146, 178. Disintegration of Soil, 55-56, 62, 65, 69. Distant, Mr. W.L., 270? 287. Dividends, 105. Domestication, 17. Doom Dooma, 224. Drainage, 18, 25, 33, 63, 6696, 345, 409, 4". Drainage by wells, 89. Drainage, Natural, 80. Drainage, Sub-soil, 80, 82, 85, 88. Drainage, Surface, 80, 81, 82, 83, 90. Drained, Over, 75, 76. Drains, Banking of, 81, 82, 83, 84. Drains, Brush-wood, 82, 89. Drains, Change of positions of, 94. Drains, Depth of, 76, 82, 83, 85. Drains, Dry the Soil, 66, 77, 83, 84, 90, Drains, Lateral, 82. Drains, Open, see Drainage, Surface. Drains, Outflow, 79, 85. Drains, Pipe, 63, 72, 82, 85, 88-94, 177. Drains, Renewal of, 93-94. Drains, Spacings for, 78, 85. Drains, Stone, 89. Drains, supply moisture, 77, Drains, Trunk, 79, 85. Driver, Mr., 276, 279, 291, 349. Drought, 69, 71. Dry Rot, see Pestalozzia Guepini. Duars, 196, 236, 261, 370, 388, 389, 390, 391, [ 392, 420, 434, 445, 460, 464. Dudgeon, Mr., 205, 210, 270, 273, 277, 279, [ 280, 285. Dulau & Co., Messrs., 320. Dumar Dallang, 3, 314. Dnm Duma, 6, 398,432, 442. Duncan Brothers & Co., Messrs., 388. Dutt, Babu G. C., 264- Dyer, Mr. W. T. Thiselton, 179. 327.418, [419. 433. 464- Early Crops, 68. Edgar, Mr. E. L., 186, 218, 302. Eggs of insects, 183, 187, 195- . Elaborated Sap, see Assimilation. Elzeagnus hortensis, 171. Elephants, 370. Emmering, Prof., 171. " Englishman," The, 264, 267. Entojhyte (=living within the Epiphytic (=growing on leaves}, 5, 41*- Ericerus pela, 319. Erineum, 23, 393. 39 6 - INDEX. Enobotrya japonica, 435. Eriochiton cajani, 320, 328, 335 374- Eriochiton nov. sp., 327 29. Erythrina lithosperma, 166, 459. Estigena pardalis, 230. E. sp., 230. Eumeta, see Clania. Euphorbia heterophylla, 411. E. pulcherrima, 328. Euproctis sp., 237. Eurya japonica, 26. Euschema militaris, 342-43. Evaporation, 36, 67-68,69, 70. Evojvulus nummularia, 438. Ewart, Mr., 167. Exchanges, see Seed. Exhaustion, 14, 18, 20. Exobasidium vexans (=Blister Blight), 23, [ 24, 33 393> 4i6, 419 28. Exotics, 65. Experiments, n, 13, 62, 94, 157, 158-9, 178, "[ 283, 286, 309, 385, 408, Me Experiments with Mosquito, 297 301 Extension, see Clearances, New. Extent of explorations conducted, 32 Faggot worms, 201 4. Faggot worms, Spiral, see Clania holmesi. Felt gall, 403. Felt-mites, 23, 393. Fern, Poisonous, as an insecticide, 12. Ferns as Weeds, 411, 465. Fertility, see Soil. Fibrils, see Root, absorbent hairs of. Ficus, 279, 290. Ficus stipulata, 434, 437, 438. Filter (Soil acts as), 69. Financial considerations, 45, 63, 93, 116. Finlay, Muir & Co., Messrs., 237, 249. Fiorinia camellise, 324-25. F. fioriniae, 324-25. F. palmse, 324-25. Firing Estates as a Remedy for Mosquito, [285. Firing Tea Bushes, 193-94, 210, 212, 217, 254, 279, 285, 322, 329, 332, 336, 399, 400, 412, 416, 417. 457 458, 463- Fish, 162. Five-ribbed Tea mite, see Typhlodromus [ carinatus Fleet, Mr. W. J., 187, 194, 223, 302, 454. Flies, Cattle, see Diptera. Flies, Horse, see Diptera. Flies, Lace-winged, 315. Fly, The, see Diptera. Flood, 67, 76, 77. Flower, The, 33, 97, 99. Flowering of Tea, 16, 18, 38, 39, 97. Flushing, 16, 29, 31, 38, 39, 46, 68, 105, 111, [ 116-17, 120. Flushing Decrease of, 121. Flushing Dependent on Bush, 131, 150. FlushingEarly, 31, 48, 68. Flushing, First, 135, 151. Flushing Late, 29, 68. Flushing Length of Shoot, 152. Flushing, Number of, 138, 146, 150. Flushing power, 101, 108,110, 114, 116-17, [ 128, 131-32, 141. Flushing Season, 151. Flushing Shaving off shoots, 120, 153, 156. Flushing Shoots, Age of, in, 120, 124, 131. ; Flushing, Third, 138. Flushing, Years of possible, 20, 40, 74, 120- [21, 128, 157. Fluted-scale, see Icerya purchasi. Fly, Black, see Ceylonia theaecola. Fly, Frit, 257. Fly, Gad, see Diptera. Fly, Hessian, see Diptera. Fly, Rice, 257. Fly, Tea, Leaf-mining, see Oscinis these. Foliage Plants, 97. Food of Plants, 3336, 39, 56, 66, 70, 133. Foot-ball, 342. Fork, Use of, 56-57. Frit fly, 257. Fruit, Cultivation for, 106. Fruit, The, 33, 42, 97, 99, 106. Fruiting, see Flowering. Fulgoridae, 310-311. Fungal (=Fungus belonging to the Fungi), [2025,51, 178,179- Fungi, Black, 27, 266, 319, 327332> 433- Fungi on the Leaves, 41228. Fungi on the Roots, see Root. Fungi, Parasitic on Insects, 320, 324, 331. Fungi, Saprophytic, 185. Fungoid (=resembling fungi), 5. Gabru, Wild Tea, 41. Gad Fly, see Diptera. Gair, Mr., 398. Gall-flies, see Hymenoptera. Gall-mites, see Phytoptus. Gammie, Mr., 273. Gardener, English, 97. Gardenia gummifera, 363. G. lucida, 363. Gastropacha pini, 228. G. quercifolia, 228. G. sp., 228-29. Gauhati, 444. Geddes, Mr. J. R. E., 229. General principles, 2. Geometridae (Geometres), 231, 241 43. Germination, 35, 121. Giladharee, 7, 442. Gilbert, Mr., 169. Gileki, 3, 6. INDEX. vii Ging Factory, Darjeeling, 289. Girdle, 235. Gluten, see Nitrogenous Matter. Gnats, see Diptera. Goal para, 444. Golaghat, 4, 130, 189, 214, 232, 261, 297, 307, [405, 441. Gollam, Mr., Report on Gondal Paint, 365. Gondal Paint, 127, 129, 36369, 410. Gopalpur, 3. Gopesadarhu, 7, 296, 308, 407, 428, 442. Gordonia Wallichii, 266. Govisana, see Acanthopsyche. Gracilaria theivora, 27, 24348, 255. Gram, 356. Grasshoppers, see Orthoptera. Green, Mr. E. E., 28, 29, 179, 192, 196, 197, 199, 201,202, 204, 208, 211, 215, 216,217,218,219, 222,224, 237, 240, 243, 248, 249, 255, 259, 264, 270, 280, 302,311,312,313,314, 315, 316,317, 319,320,321,322,323, 324, 325,326, 327, 328, 330, 331, 333, 334, 336, 340, 343,372,373.377. 383.388, 390,392. 393 395. 399, 4 4i3- Green-beetle, see Astycus. Green Bug, see Lecanium viride. Green Colour of Mosquito, 267 70, 271-72, [280, 295 Green Colouring Matter of Plants, see Chlo- [ rophyll. Green-fly, see Chlorita flavescens. Green Manure, see Manure. Grey Blight, see Pestalozzia Guepini. Griffith, Dr., 41. Grote, Mr., 194, 267, 268, 302. Growth, 3539- Growth Retarded, 103-104. Grub (the larva of Beetle), 182, 195. Grub, Black, see Agrotis ypsilon. Grub, white, 182-86. Guano, 162. H Habits of Insects, 31. Hairy Caterpillars, see Lasiocampidse. Hairy Poisonous Caterpillars, 230, 231. Hall, Mr. James, 350. Hampson, Sir George, 195, 196, 198. I99> 200,201, 202,204, 207,210,213, 215, 217, 221, 222, 223, 224, 228, 232, 236, 237, 238, 239, 240, 241, 242. Hand picking Caterpillars, 195, 198. Hannay, Colonel, 171. Harcourt, Mr. C. N., 266, 270, 276, 289. Hares, 370. Harrison, Mr., 237. Harry, Mr. W. A., 407. Harting, Mr. R , 459, 465. Hathibari, 7. Hautley, 261, 350, 354, 432- Health of plant, 32, 141, i44> U8- Heat, see Soil Temperature. Helicarion salius, rjo. Hellriegel, Mr., 169. Helopeltis, 319. H. antonii, 269, 270. H. febriculosa, 270, 273. H. theivora, 4, 10, 11, 12, i3,. 2 6, 31,48, [ 1 80, 191, 264301, 374, 385. lemileia vestatnx, 20-21, 158. Hemiptera, 264337. 4", 433- Henderson, Mr., 297, 428, Henderson & Co., Messrs. George, 311. Herbivorous insects, 25. Hereditary, 51. Hessian Fly, see Diptera, 255-257. Heteroptera, 264, 316. Heterusia cingala, 201. Hibernation, Protection of, 83, 269. Hibernation, see Mosquito. Hibernation, see Red-spider. Hibiscus plants, 279, 290. Hide-bound stems, 6, 411. Hilgard, Mr., 163, 165. Hilly slopes under Tea, 73. Hiltner, Mr., 171, 174. ffingra, see Asafcetida. History, Life, of Pests, 13. Hodges, Mr., 164. Hoe hand, 58. Hoeing before Transplanting, 65. Hoeing, Collection of Grubs and Cocoons [ during, 185, 198. Hoeing Clod, 81, 83. Hoeing constantly, 349. Hoeing, Deep, 17, 58, 60, 61, 68, 127. Hoeing, Double, 94, 95. Hoeing, Dutch, 59. Hoeing, Light, 58, 60. Hoeing, Number and depth of, 56-57, -ft, 89. Holland, Mr. W. D., 222. Holly-leaved Tea, 47. Holmes, Mr. A. B., 127, 141,405- Holta, 3, 208, " Home and Colonial Mail," 153, 265. Homoptera, 264, 310, 316. Honey-dew, 319. Honey-yielding Teats, 312. Hooker, Sir J. D. f 330. Hooper, Mr. (New Zealand), 465. Hooper, Mr. D., 12, 161 75 Hornbean, 235. Horse Flies, see Diptera. Horticultural knowledge, 97. Horticultural Society, Royal, 465. House-forming Tineid, 25254. Howard, Mr. L. O., 232, 320, 321. Hughes, Mr., 164. Hukanpukri, 191. hullah (=depression or low-lying tract of & tea garden, often partly under water), 79, 89, 290, 298. Humidity, see Soil. Humus, see Organic Matter. Hunter, Mr. J. A. A., 442- INDEX. Hybrid, see Stock. Hybridism, 49-50, 53. Hydrogen, 34. Hylakandy, 267. Hymenoptera, 25760, 315, 319. Hymenomycete origin, 463. Hypsa alciphron (Hypsidse), 238. Icerya segyptiacum, 317. I. purchasi, 317, 318. Ichneumon- flies, see Hymenoptera. Ichneumonid insect, 234. Ilbert, Mr., 279, 285, 290. Imago (=Perfect stage of Moth or Butter- [ fly). 195- Immature, n, 32. Immunity from Blight, 14, 30, 31, 346. Imperata arandiacea, 59, 62, 64, 188, 189, [411. Improvement, 32, 44. India, South, 261. Indian Forester, 459. Indian Museum Notes, 28, 179, 181, 183, 186, 189, 191, 192, 196, 199, 203, 204, 207, 213, 218, 222, 223, 224, 230, 232, 239, 240, 241, 243, 249, 255, 262, 264, 266, 270, 295, 303, 308, 310, 311, 318, 320, 321, 322, 325, 327, 328, 330, 335, 337 340, 373 427- Indian Wax insect, see Ceroplastes cenferus. Indigenous, see Stock, Assam, also see Wild Tea Plant. Indefinite production, 18, 40. Inoculation, see Soil. Inorganic Matter, 34. Insect collecting nets ; also the collection of winged insects, 185, 190, 195, 198. Insect, Definition of, 181. Insecticides, 9, 1013, 25, 212, 254, 283, 303, [ 309, 3i6, 336, 382. Interlining, see Bushes. Internodes ( = spaces between the leaves), 306. Interplanting, 20, Inundation, see Flood. Ipomaea, 427. Iron salts, 69, 162. aipur, 6, 214, 252, 291, 389, 425, 441. alpaiguri, 321. amcson, Dr., on Drainage, 72. apan, System of Drainage, 74. ardine, Skinner & Co., Messrs., 196, 265. assidae, 302310. c ats, see Races. ava, 270, 271. Jenkins, Mr., 291. .Jetukia, 4. Jheel f=a marsh, equivalent almost to the Assam word Hullah which see). Jokai, see Panitola. orhat, 4, 196, 218, 238, 239, 251, 261, 262, [ 293. 3i i > 397. 398 4i3 426, 441- Julus-worms, 370, 371. Jungles, Plant Diseases in, 46, 21, 22, 26, [27. Jungles, Surrounded by, 25, 26. K Kaliden, 231, 297, 458. Kangra Scale insect, see Aspidiotus these. Kangra visited, i, 3, 8, 16, 27, 29, 83, 208, 213* 261, 321, 322, 323, 411, 413. Kellyden, 7. Kerosine Emulsion, 316, 323, 336, 349, 360, [ 386, 392. Kew Bulletin, 459, 464. Khet ( =field), 89. Khonikor, 6. Khumtai, 3, 183, 184, 393, 396. Khwang, 3 Kidney-bean, see Phaseolus. King, Sir George, 99 (on Pruning^, 112, 179, Kirwan, Mr., 224, 225. Kohima, 5, 6. Koliabar, 7, 297, 442. Kotagiri, 318. Kufu, Wild Tea, 41. Kumaon, 261, 311. Kumber, 303. Kumia (=Vern. name for Lachnosterna [ which see). Labour, 74. Lac insect so-called, see Ceroplastes myrica?. Lac insect (true), see Tachardia lacca. Lace-winged Flies, 315. Lachnosterna impressa, 182 86, 261. Lady-bird, Australian, see Vedalia cardin- [ alis. Lady-bird beetles, 190, 289, 315, 318. Lakhimpur (North), 7, 12, 27, 65, 118, 192, 213, 218, 219, 272, 282, 296, 311, 3H. 330, 333. 398, 407. 420, 427, 442, 444* Lane, Mr., 365. Lankester, Professor Ray, 269. Lantana, 327. Lappet Caterpillar, see Gastrophaca sp. Large Scale Bug, see Lecar.ium sp. nov. Larvae (=caterpillars of an insect), 182, 196^ 296, 3i5 33L 332, 335, 336, 337 372, 402. Lasiocampidse, 228 30. Late crops, 68. Late Flushing, 29. Laurel-leaved Tea, 46. INDEX. Laying out of estates, 409. Lawrence, Mr., 233, 234. Lawes, Mr., 169. Leaf-borer, see Ocinis these. Leaf changed by cultivation, 16. Leaf crops (Tea, Pan and Mulberry), 10, 19, Leaf, Green, Weight of, 153, 155. Leaf, mimicry, 200. Leaf-mining Fly, see Oscinis these. Leaf- Rollers, Tea, see Gracilaria theivora. Leaf-Rollers, see Tortricidas. Leaf- Rollers, Kangra Tea, 248. Leaf, Size of, 15. Leaf-Tier, Indian, see Sandwich Caterpillar. Leaf -Tiers, see Tineidae. Leaf, The, 33, 36, 70-71, 91, 97, iai, 141, [ 161. Leaves, Black fungi on, 433. Leaves, Brown Blights on, 428 33. Leaves, Brown Rings on, 432-33. Leaves, Brown spots (with pale rim) on, [ 428- 30. Leaves, Chestnut Patches on, 431-32. Leaves, Closing up, 48-49. Leaves, Fungi on, 412 428. Leaves, Marbling of, 431, 449. Leaves, Marginal Corrosion, 430. Leaves, Number of, on Shoot, 101, 141 145, [ !53- Leaves, Old and Young, 39, 154. Leaves, Orange-red spots on, 446. Leaves, Removal of Old, 115. Leaves, Skeletonised, 233. Leaves, Stripped off in Plucking, 14549, Leaves, Tearing off half in Plucking, 139 40, I 146, 147, 149, 150, 151. Leaves, Turned over and attacked by a [ fungus near the base, 430-31. Lebong, 237. Lecanimae, 320, 328, 334. Lecanium coffeae, 27, 317, 33033, 334. L. formicarii, 259, 319, 323, 333. L. nigrum, 27, 317, 330 333. L. sp. nov., 333. L. these, 259, 323. L. viride, 317, 330333. L. wattii, 333. Lees, Mr. J., 196, 252-53. Leguminosse (=the Natural Order of plants represented by the Peas, Beans, Clo- ver, Lucerne, etc.), 169, 170, 171, 173, 174. Leguminous, see Nitrogen giving organ- [ isms. Lepidiota, 184, 194. Lepidoptera (=moths and butterflies), 195 Letch i, 446. Letters affixed to names of Pests and [Blights, 181. Lichens, 5-6, 411-12, 445, 448. Life histories, 32. Lign Pukri, 3, 4, 141, 183, 197, 198,200,213, 226, 230, 236, 238, 239, 242, 243, 245, 250, 333, 397, 406, 432. Limacodes graciosa, 27. Limacodidse, 220228. Lime (=Calcium) and Salts of, 162, 164, 165, 1 66, 286, 386, 418, 424, 440, 441, 463. Limpet Caterpillar, see Acanthopsyche Linde, Mr., on Drainage, 74. Lines, Coolies, 31. Liotard, Mr., 340, 362. Liver-worts, 411. Lloyd & Co., Messrs., 268. Loam, see Soils. Lobster Caterpillar, see Stauropus. Locusts, 260. Loharduggah, 349. London Purple, 10. Longicorn beetles, 182, 194. Long-scale, see Mytilaspis gloveri. Looper Caterpillar, 231,241. Loquat, see Eriobotrya japonica. Loranthus (=a parasite allied to the Mis- [tletoe),5i, 4 io-ir. Loss by Mosquito, 265. Lotus Tetragonolobus, 167. Louse, Tea Bark, see Chionaspis biclavis. Louse, Tea Leaf White, see Chionaspis [these. Louse, Transparent Scale Bark, see Aspidi- [ otus !atani;c. Louse, White Tea Leaf, see Chionaspis [the* Louse, Yellow Bark, see Aspidiotus camel- [liae. Lucerne, see Medicago sativa. Luckwah, 4. Lungs of the plant, 33, 132. Lupin (Lupinus luteus), 170, 177. Lushai, see Stock. Lymanlriidse, 23038, 241. M Macaranga Roxburgh!!, 167. Macdonald, Mr. P. J., 277, 278, 281. Machilus, 446, 459. Mackillican & Co., Messrs., 196. Macrodactylus subspinosus, 183. Madden, Mr., 130, 403, 404, 406. Madder, see Erythrina. Maesa indica, 4, 26, 27, 270, 294. M. montana, 266. Maggots, 182. Magnesium salts, 162. Magnolia, 413. Maikipur, 3. Makum, 6, 293, 391, 393, 406. Mango, 446. Mango attacked by white-ants, 355. INDEX. Mango bushes supposed to be punctured by [Mosquito, 294. Manipur, see Stock. Manufacturing leaf various quality, 149. Manurejand Manuring, 18, 23, 56, 63, 72, 77, 82, 89, 92, 95. 96, 127, 133, 146, 153, 160, 161 177, 176, 185, 409. Manuring, Green, 57, 6264, 95, 153, 166 [ 68, 185. Maples, 465. Margherita, see Makum. Maskell, Mr. W. M., 320, 322, 323, 325. Massee, Mr. George, 179, 327, 418, 419, 459, [461, 464. Masters, Mr. J. W., 59. Matheson & Co., Messrs., 86. Mail Kalai, see Phaseolus aconitifolius. Mazenga, 3. Mealy-bug, see Dactylopius destructor. McClelland, Dr., 41. McLeod & Co., Messrs., 388. Medeloa, see Dalbergia assamica. Medicago saliva (lucerne), 167, 174. Melamphaus, 288. Melang, 4. Melia, 459. Melolontha vulgaris, and Melolonthin [ Beetles, 183, 184. Michael, Mr. J. S., 196. Microscopic Society, Calcutta, 317. Mid season, 17. Middleton, Mr., 239. Migration of Pests, 29. Mijikajan, 7, 296, 387, 408, 442. Miles, Mr., 264, 303, 317. Millepedes, 370, 371. Mimosa pudica (Sensi pudica ^sensitive Plant), 173, 177. Mimosese (=a sub-order of Leguminosae) (which see) represented by the sen- sative plant, the Babul, and the Sa trees, 171, 173. Mineral substances, 33-34, 37, 56, 66. Mite, Five-ribbed Tea, also Mite, Purple, [ see Typhlodromus carinatus. Mite, Red, see Tetranychus bioculatus. Mite, White, see Typhlodromus carinatus. Mites, 29, 49, 314, 370, 372408. Mixed stock, 45-46, 48, 50, 53, 149. Moaband, 4, 199, 214, 215, 225, 226, 227, [ 229, 251, 398. Moir, Mr., 443. Moisture, see Soil humidity. Mokokchang, 6. Mole-cricket, 263. Molusca, 370-71. Money, Colonel, on Hoeing, 59 ; on Drain- age, 72 ; on Burying of Prunings, 95 ; on Plugking, 146, 261, 264, 266, 340, 349, 360. Moore, Mr. F., 187, 189, 194, 200, 203, 216, [ 233, 267, 268, 302. Moran, 3, 187, 188, 197, 213, 222, 232, 285, [ 290, 291, 314. Moran & Co., Messrs. W., 370. Moriani, 198. Morinda, 26, 364. Morinda citrifolia, 363. Mosquito, see Helopeltis. Mosquito, Census of, 283. Mosquito, Collection of, 283. Mosquito Eggs, Hatching of, 127, 277. Mosquito, Green colour of, 267270, 271- [ 72, 280, 291, 295, 304. Mosquito, Hibernation of, on Tea plant, 13, [ 275, 276278, 284. Mosquito, Hibernation, in Bamboo and Tun, Mosquito, Hibernation of, in Water, 278. Mosquito, Hibernation of, in the Ground, Mosquito, Orange-red colour of, 271. Mosquito Plucking as a remedy for, 279- [ 80, 284. Mosquito, Natural enemies of, 274, 276, [287,288. Moth, see Lepidoptera, 195. Moths, Nocturnal, 240 243. Mouths of the plant, 33, 132. Mosses, 411-12. Mukhamcherra, 249. Mulberry Cultivation, 10, 83, 97. Mulching Weeds into the Soil, 168. Mulhakattyoor, 311. Muller, Mr., on Hoeing, 58; on Shape of Bush, 113; on Pruning, 117; on Plucking, 146. Mungphu, 273. Munguldye, 194, 209, 311, 444. Mussel-scale, see Mytilaspis pomorum. Musubar, see Aloes. Mycoidea parasitica, see Cephaleuros vires- [ cens. Myriapoda, 370-371. Mysore, 167. Mytilaspis citricola, 317. M. gloveri, 317. M. pomorum, 317. N Naga Hills, 3, 4, 5, 6, 41. Nagas as Coolies, 102. Naharani, 4, 297. Nahor, 446. Nahorhabi, 4, 228, 229. Nahorrani, 7. Namber Forest, 4. Namsang, 6, 30, 41, 50. " Nature," 269. Nazira, 3, 6, 197, 198, 232, 250, 314, 333, 397, [441, 444- Neglect, 22. Nephrodium aridum (=Poisonous fern), 12. Nettle-grub, Blue-striped, see Pavasa lepida. Nettle-grub, Brown-striped, see Thosea divergens. INDEX. Nettle-grub, Green striped," see Thosea di- [vergens. New Guinea, 268, 270. New Red spider, see Tetranychos sp. Newstead, Mr. R., 329. New Zealand, 464, 465. Niceville, Mr. L. de, 264. Nietner, Mr., 20, 26, 27, 28, 217, 220, 239, [ 330. 393- Nigali, 328. Night-feeding Caterpillar, 223. Nigiriting, 4, 141, 187, 213, 214, 226, 229, [ 242, 282, 398, 404. Ningrew, 41. Nitrates, 37, 80, 168. Nitric Acid, 34, 56, 69, 168. Nitrification, 168. Nitrogen, 3335.37* 63, 65, 69, 94, 153. [ 163, 165, 166, 170, 174, 242. Nitrogen giving organisms, (alternate strips of land for), 37, 56, 6364, 69, 92, 163, 168. Nitrogenous matter, 35, 37, 162. Noad, Mr. G.E.,35i. Noakachari, 4 213, 232, 251, 306, 308. Nobbe, Mr., 171, 174- Noctua suffusa, see Agrotis ypsilon. Noctuidae, 240-41. Nocturnal Moths, 24043. North Bank (=Tea land on north side of the upper portion of Brahmaputra), 196. North-West Provinces, Tea in, 60. Notodontidse, 199-200. Nowgong, 7, 27, 187, 231, 241, 249. 282, 297, 394. 4i3 420, 442, 444. 454. 45> 459 - Nullah (= Stream, employed to denote drain- age channel), 75. 77. 89. 298. Numbers Assigned to Pests and Blight, 182. Numenes siletti, 238. Nursery, 109, 316, 392, 400, 409. Nutritive system of plants, 33. Oak, 235. 465- Ocinis these, 28, 25557, 266. (Ecophylla smaragdina, 259, 319- Oides bipunctata, 194. Oil -cake, 166. Oils, 35- Old Districts, 20. Old Gardens, 18, 22, 155. Omnivorous insects, 26, 465. Ophideres fullonica, 241. Ophiusa melicerte 241. Opinions, Exchange of, 180. Orange Beetle, see Diapromorpha. Orchard, 97, 167. c .. Organic matter, Oxidation of S 01 1 an Humus, 56, 57. 6 4 6 9> 88 > l6x 6 ' 163-64, 1 66. Orgyia leucostigma, 232. Ormerod, Miss E. A., 186, 193, 228, 386. Orthezia insignis, 327. Orthoptera, 260 63. Osbeckia, 266. Oscinis these, 255257, 266. Osmose (=Law of Circulation), 35, 36, 37-38. Out-flow, see Drains. Jut-Gardens, 19. )ver Cultivation, 61, 63, 64. Dver Plucking, see Plucking. )vipositor, 219, 269, 274. )vum, 275. Dxidation, see Organic Matter. Oxygen, 33-34, 36, 56, 69, 168. Paecilocoris hardwickii, 301-302. Palampur, 3. Pan, see Piper. Panitola, 6, 130, 252, 293, 294, 307, 403, 406, [427. Papilionaces3(=a sub-order of the Legumi- L nosas) which see. Parasa lepida, 27, 223, 224. Parasite(=a plant or animal that lives on another: Saprophyte=a plant or animal that lives on dead organic matter), 96, 185, 251, 269, 380. Parasites, See Loranthus. Parasites, Leaf, 412459- Parasites, Vegetable, 309-363. Pareba vesta, 195. Paris Green, 19. Parthenogenetic, 312. Patalipam, 7, 65, 118, 229, 232, 249. 252, 272, 273; 281, 294, 306. 326, 33L 39, 399. 407. 427, 442- 197, 202, 204, 218, 2I, , , 264 265,267,268,271,272,274,287. 291, 292, 302, 303. 304. 306, 373, 419, 420, 421, 422, 425- Peal's Beetle, see Diapromorpha. Pekoe Teas, 139' J4& iab> Pentatomid Bugs, 302. Perennial Crops, 18, 57. 64. 6 5 73- Perforating, Leaf.CaterpU Ian, 213- Period of Assam Exploration, 3.8- Perman, Mr., 229. Pertabghur, 7. Pestal&iia Guepini, 23-24. Pests (=Animal parasites and enemies),^. Pests, Increase of, see Blights. Phaseolus acomtifohus <-- I> I77 , 331. Phenyle, 316, 392- INDEX. Philippines, 270. Phospho Phosphorus (Phosphates and Phosphoric Acid) as plant food, 35, 162, 165 66. Phromnia marginella, 310-311. Phyllosticta, 433. Phylloxera, 9, 318. Physical Phenomena, 39, 70. Physiological Disturbances, 55. Phytoptidse, 407. Phytoptus, 372. P. pyri, 24, 403. P. ribis, 403. P. these, 29, 30, 307, 391, 400408. Pike, Mr. Melville, 267, 274. Pine trees, 107, 465. Pink Mite, see Phytoptus theae. Pinney, Mr. G. F., 202, 311. Pintia ferrea, 201. Pipe, see Drains. Piper (=Wild Pan), 5, 10, 277, 291. Pisum sativum (=the Pea), 42, 174. Pits to catch wash, 73, 74. Plant, Health of, 105. Plant, Starvation of, 104. Plant, Young, Better return from, 20, 157, [ 160. Plant Bugs, see Hemiptera. Plant Life, 3340, 69, 105, 161. Plant Lice, see Hemiptera. "Planter," The, 187, 189. Planters, Co-operation of, 8, 13, 180. Planters' Stores and Agency Co., Ld., 224. " Planting Opinion," 318. Plants per acre, 9. Plants within the Bushes, 411. Plucking, 32, 39, 92, 100, 117, 131160, 269, [409. Plucking, Age of Shoots, 141, 150. Plucking as a Remedy for Mosquito, 279- [ 80, 284- Plucking, First, 135. Plucking for Quality, 13641, 151. Plucking for Quantity, 134-35- Plucking, Over, 15355. Plucking Season, 145. Plucking with portion of leaf, 139-140, 146, [ 147, 149, 150, 151. Plum, 186, 193. Poinsettia, see Euphorbia pulcherrima. Poison, lo-n, 13. Poisonous bite, Supposed, 209. Poisonous compounds in Soil, 80, 88. Polygonum sp., 4, 266. Potash, 161, 165. Potatoes, 42, 465. Pourridi6, 464. Prain, Dr. D., 179, 435. Prazmowski, Mr., 170. Predisposition to diseases, 17, 18, 25, 28, [55. 131. 158* 161, 178, 181. Preferences, 25. Prevention, 18, 32, 454. Principles involved, 25. Pringle, Mr., on Drainage, 76, 85, 90. Production (= yield to acre), 20, 40. Productive Power, 20, 114. Prolegs (=the temporary or sucker legs of [ a caterpillar), 195, 246. Proof against blights, 31. Protein (Proteid compounds), see Nitrogen- [ ous Matter. Pruning, 17, 25, 32, 38-39, 40, 52, (seed), [ 53. 97i30 220, 269, 347- Pruning (Meaningless mutilation), 101, 102, [ 117,347,409,412. Pruning, Age of first (seedlings), 105, 107- 8, 113, 116-17, 120, 129, 130, 141. Prunings, Burning of, 96, 121, 359, 399, 439, [ 441, 456. Prunings, Burying of, 94-95, 359, 453, 458. Pruning by Handfuls, 102. Pruning, Collar, 20, 105, 109, 118, 119-120, 12127, I28 ' r 56, 212, 399, 400, 412, t 416, 439, 440, 457- Pruning, Collar, Date of, 115, 123, 127, 130. Pruning, Collar, Death rate, 123-24. Pruning, Destruction of, 284-85. Prunings, Disposal of, see Prunings, Burn- [ ing of. Pruning, Diversities in, 97 99. Pruning for Buds, 103. Pruning, Heavy, 104, 119-20, 122, 130, 377. Pruning, Light, 102, 119-20, 412. Pruning, Objects of, 97, 100-101, 105, 113, C "7- Pruning on Merits, 64, 100, 102. Pruning, Position of Section, 102 105, 109, [ 123, 127. Pruning, Season of, 11416, 118, 123, 127. Pruning, Shape of, 98. Pruning, Theory of, 99 101. Pruning to height, 57, 64, 100, 117. Pruning up, 118. Pruning with Snags, 103, 105, 109, 117, 129, _ . , C !34> 220, 347. Pruning, Wound of, 103. Pseudoneuroptera, 339 69. Psyche albipes, 216. Psyche assamica, 208, 21517. Psychid, Leaf -perforating, see Acanthopsy- [ che snelleni. Psychid, The Conical, 215- 17. Psychidse, 20117. Pulvinaria psidi, 327. Pupa skin, 225. Puparium (=Scale), 325. Purchase seed, 30. Purple mite, see Typhlodromus carinatus. Purple-scale, see Mytilaspis citricola. Pyrenomycete, 464. Duality, see Plucking. >uality, Depredation of, 74, 121, 160. Juality, Explanation of, 151, 175. INDEX. xiii Quality of Tea, Improvement of, 63, 121, [ 1 60, 175, 176. Quantity, see Plucking. Quick Lime, 418. Races (=iats), Influence of, 20, 29, 50. Races of Tea plants ( = jats), 15, 19, 4648, 50, 52, 55. 381, 384, 403, 406, 407, 422. Raider White-ant, 342. Rain, see Water. Rainfall, 123, 153. Ramsden, Mr. E., 191. Rats, 370. Red Ant, see CEcophylla smaragdina. Red-black Ant, see Cremastogaster contenta. Red borer, see Zeuzera coffea?. Red-mite, see Tetranychus bioculatus. Red Rust, see Cephaleuros virescens. Red Spider, see Tetranychus bioculatus. Red Spider, Hibernation of, 13, 385. Red Spider, New, see Tetranychus sp. Reduviid, 270, 287,288. Keforms in Agriculture, 13. Reforms in Tea planting, 31-32. Reid, Mr. George, 126. Renewal of Stock, 18, 20. Replanting, 20. Report, see Scope of. Repose, Periods of, 71. Reproductive system of plants, 33, 38. Respiration, 34, 37, 154. Rest during Winter, 17. Rest required by plants. 39, 127, 134. Results attained, 19. Results, Unsatisfactory, 8. Returns, 20, 157. Rhododendron, 413. Rhopalum sp., 315. Rhynchota, see Hemiptera. Rice fields, 79. Rice Fly, 257. Robertson, Mr., 362. Robinia, 174. Rollers, Leaf, see Gracilaria theivora. Root, Absorbent hairs of, 69, 70, 83. Root, Fungi on, 23, 96, 185, see also Rosel- [ linia. Root Pruning, 53. Root, Tap, 91, 106, no, 112, 116, 118. Root, The, 33, 39, 69, 70, 90-91, 106, 107, [ 122, 161. Root Tubercles, see Nitrogen giving organ- [ isms. Roots bearing shoots, 121-22. Roots, Disturbances of, 56, 58, 107. Roots eaten by grubs, see Lachnosterna [ impressa. Roots, Lateral, no. Roots, Multiplicity of, 112/128. Roots, Penetration of, 90. Rose Bushes, 27, 42, 465. Rosellinia sp., see Root, Fungi on. R. radiciperda, 459 67. Rotation of Crops, 18, 64, 65, 89, 92, 155. Kunga jam, 202,311. Sa or Sou, see Albizzia stipulata. Saccharine secretions, 27. Sal, see Shorea robusta. Said, 7, 297, 443 . Sa onah, 7 , i8 7 , 297, 428, 442, 458. Salt, 418. Saltpetre (=Potassium nitrate), 165, 168. Sand, 67, 163. Sandwich Caterpillar, 246, 249252, 441. Sap, Ascent of, 36, 103, 115. Sap, Circulation 01,3537, 70, 134. Sap, Crude, 36. Sap, Descent of, 37, 104. Sap, Obstructed, 103, 104. Sapodilla plum, see Achras sapota. Saprophyte, see Parasites. Saturniidse, 195. Saunders, Mr., 186. Saw, Use of, 123, 125, 126. Saw-flies, The, see Hymenoptera. Scale Bug, see Coccidas. Scale Bug, see Eriochiton cajani. Scale Bug, Large, see Lecanium sp. nov. Scale-insect, 255, 259, 264, 31637, 411, 433. Scale-insect, Kangra, see Aspidiotus theae. Scale Louse, Assam, 324-25. Scaly-bugs, see Lecanium coffese. Scaly-bugs, see Coccidae. Scaly-bugs, Darjeeling, see Eriochiton nov. [sp. Scarth, Mr. E., 350. Schima Wallichii, 26, 266. Schrottky, Mr., on Drainage, 76, 82, 86, 89, [373. Scientific Assistance, 32, 181. Scientific determinations, 25. Scientific investigations, 14, 268. Scissors, Use of, 100. Sclerotia (=resting spores), 434, 435. Scope of Report, 1-2,32, 33, 55, 178. Scorpions, 370, 372408. Scott, Mr. J., 340, 343. 35 1 - Season, Mid, 17. Season of Flushing, 46, 64, 68. Seasons of Pests, 9, 46. Seconee, 7, 297, 387, 408, 458. Seed at Stake, 118, 240, 409. Seed, Bushes allowed to, 53. Seed, Collection of, 52. Seed Exchanges, 54. Seed Gardens, 41 54. Seed Growers, Professional, 45, 52. Seed, Production of, 53, 131. Seed, Ripe, 53. INDEX. Seed, Selection of, 30, 4143. Seed, The, 33, 52, 131. Seedlings, Health of, 112, 141, 148. Seedlings, Pruning of, see Pruning. Seedlings, Shape of, 14, 105 107, 115, 141. Seedlings Transplanted, 109, 120, 122, 409. Selang, 4, 229, 232. Selection of Seed, 32. Selection of Sites, 52, 73, 409. Selection of Stock, 51, 286. Sepon, 3, 232, 236. Serispur, 267. Shade and Shade Trees, 166, 172, 269. Shakomato, 287. Shan States, 42, 218. Shaw, VVallace & Co., Messrs., 322, 323. Shell, Living, 124, 347. Shencotta, 167. Shipp, Mr., on Hoeing, 58 ; on Drainage, 72; on Shape of Bush, 112; on Plucking, 145-46- Shoots, Age of, 136, 137. Shoots, Continuous production of, 131, 133, Shoots, Multiplication of, 138. Shoots, New, 39, no, 111-12, 115, 120, [ 124, 131, 135. " Sooty Bug," 319. Shorea robusta (sal), 205, 236. Shut up, Gardens, 20. Sibsagar, 3, 12, 23, 95, 184, 187, 192, 208, 212,218,222,228, 247, 249,258, 271, 279,282,285, 290,291, 297,311, 314, 387> 394. 398, 4^3' 4i6, 420, 424, 425, 426, 440, 444. Silghat, 7, 232, 282, 443. Silk worm, 195. Silt, 76. Silver Depreciation, 157-58. Simul, see Bombax. Single seed, 30. Singtom, 239. Sites, Selection of, 52, 73, 409. Size, see Bushes. Slug-like Stinging caterpillars, see Lima- [ codidae. Slugs, 221, 370-71. Smith, Dr. W. G., 412, 443, 459. Snag, see Pruning. Snails, 370-71. Soap as an ingredient in insecticides, 12, [383- Soil, Affinity for water, 71. Soil, Balance of, 57, 177. Soil Caking, 60-61, 69. Soil, Capabilities of, 18, 33, 56. Soil, Decomposition of (chemical and [ physical), 34, 56, 69, 70, 163. Soil, Defects in a, 32. Soil, Depth of, 66, 68, 69, 86, 107, 112. Soil, Dried abnormally, 71. Soil, Exhaustion of, 18, 20, 32, 63, 68, 74, [ 82, 88. Soil Fertility, 88, 161. Soil Humidity, 6669, 7072, 79, 84, 88, [ 90, 161. Soil Improvement, 34, 38, 56-57, 63, 67 [ 69, 74, 16177. Soil Inoculation, 174-75. Soil Oxidation, see Organic matter. Soil Percolation, 83, 88. Soil, Temperature of, 33, 56, 60, 68, 69, 88, Soils, 5, 52, 60, 6669, 85, 88, 269. Soils, Composition of, 63, 66, 161. Soils, Clayey, 60, 67, 163. Soils, Heavy, 61. Soils, Sandy, 57, 67, 86, 88, 163. Solal, 297. Solanum, 294. Soluble substances, 34, 36-37, 56, 66, 68, [ 69, 89. Somerville, Mr., 459. Somites (=joints or sections of a caterpillar), [ 198, 200, 227. Sonada, 187. Sonajuli, 7. Sonari, 425. Soongal, 3. Soongal (Kangra), 53. Soot Blight, 328, 411. Sooty Bug, 319. Souchong, 139, 146, 1 88. Spasmodic development of Pests, 199. Species of Camellia, 15. Specific gravity, 35, 36. Specimens, Value of, to the Planter, 195. Spermatazoa, 276. Sphinx (Sphingida;) moths, see Cha3rocampa [ alecto. Spider, 370, 372408. Spider attacking Mosquito, 276, 287, 289. Spiral Faggot-worm, see Clania holmesi. Sporangia, 464. Springs, 78. Sproull, Mr. H. C, 328, 329, 373. Spruces, 465. Statistics of 'Tea, 18. Stauropus alternus, 199-200. Steele, Mr., 287, 308. Steel, Messrs. Octavius, & Co., 230, 349. Stem, Absence of, 98. Stem, Blights on, 433459- Stem, Dead wood with the, 103 105, 123- [ 24, 126, 128. Stem, Formation of Central, 38, 98, 106, [ 108, 113-14, 116, 129. Stem, Gnarled, 101, 129, 133-34. Stem, Mature wood of, 131. Stem, Starvation of the, 103105, 121. Stem reduced to a shell, 347. Stem, The, 33, 122, 161. Stem, Zigzag, 306. Stilbum nanum (=Thread Blight), 23, 96, [251-2, 4H, 4i9 433 43- Stilts, Bushes growing on, see Bushes Rising [ out of the Ground. INDEX. Stinging Caterpillars, 27. Stock, Assam indigenous, 12, 14, 15, 16, 17, 19,29, 41-42, 44, 112, 189,281,287. [388. Stock, Cachar, 15, 30, 191. Stock, China, 15, 16,30,31,42,44,53,55, 112, 281,419. Stock Hybrid, 15, 30, 31, 42, 47 49. "2, [281. Stock, Improvement of, 41, 4244, 55, 160. Stock, Lushai, 19, 196. Stock, Manipur, 15, 16, 30, 41, 389, 403, [4S- Stock, Once removed, 112. Stock, Renewal of, see Bushes up-rooting [of. Stock, Selection of, 286. Stoker, Mr., on Hoeing, 60; on Shape of Bush, 113; on Plucking, 148, 168, [264. Stoklasa, Mr., 169. Stoliczka, Dr., 373. Stomata (=breathing openings on the leaf,) [ 39, 70, 408. Streams, 79. Stumps, Rotten, 123 25, 128. Stunted Blight, see Green Fly. Stunted growth, 308. Subansiri River, 7, 295, 296, 331, 407. Successful Planting, 18. Sugar, 35. Sugary fluid, 319. Suitability of Stock, 31. Sukerating, 6. Sulky, see Green Fly ; see also Apple-foliage [ Blight. Sulphate of Copper, 418. Sulphur as an insecticide, 10, 259, 316, 382, [ 383. 384, 385 386, 418, 454. Sulphur as plant food, 35. Sultanpur, 3. Sum, see Machilus. Sun Blistering, see Blistering. Sun, Rays of, 34, 36, 68, 163. Sunn-hemp, 424. Suntok, 3. Superphosphate, 162. Swinley, Mr. G. H., 296. Sycanus, 288. Sylhet, 249, 350. Symbiotic (= living together), 170. Syntomis cyssea (Syntomidse), 200. Syrphida?, 315. Tachardia lacca (=the Lac Insect), 319. Tachinid Fly (=Family of flies, the larva? of which are mostly parasitic on other insects), 201. Talap, 6. Tannin, 151, 175. Tar, 125, 127, 129, 130. Taragama sp., 230. Tasar silk worm, 205. Tassock Moth, Pale, see Dasychira pudi- [ bunda. Tea Agents, Calcutta, (Investigation of [ Mosquito), 268. Tea Aphis, see Ceylonia theaecola. Tea Association, 45, 172, 179, 218, 219, 283, T r> i T t 303> 339, 35. 366, 369, 373- Tea Bark Louse, see Chionaspis biclavis. Tea Bug, see Helopeltis. Tea Cyclopaedia, on Hoeing, 60; on Drain- age, 73, 163, 179, 183, 187, 196, 202, 204, 206, 207, 209, 215, 217, 261, 264, 302, 311, 340, 349, 373, 377, 378. " Tea Gazette, 179, 190, 260, 261, 2;2, 276, [3" Tea Leaf Louse, White, see Chionaspis [ thez. Tea Manure, 165. Tea Mite, Five-ribbed, see Typhlodromus [ carinatus. Tea Mosquito, see Hemiptera; also see [ Helopeltis theivora. Tea Planters' Vade Mecum, 77, 89, 90, 179, 182, 196, 231, 264, 33. 305 373 433. Tea, Wild, 5, 14,22, 41, 55, 67, 105, 176, 181, [287. Teak wood, 346. Teas, Finest of Season, 135. Teelah (=low marshy land), 168. Temperature, see Soil. Temperature of plant, 71. Temporary Pests, 21. Tephrosia Candida, 177. Tephrosia purpurea, 166. Termes fatalis, 28. Termes taprobanes, 12, 28, 90, 92, 103, 123- [ 24, 184, 219, 220, 261, 34069. Termes (White-ants), Agricultural form [342. attack living Plants, [346. attacking Mango, 355. attacking Seedlings, [348. Castellated form of, [34i. Ceylon Raider form [of, 343- Communities of, 343. r Different forms of, Diminish water supply, [346. Distribution of, 344. Effect on Drainage [ by, 345- Immunity of certain Timbers from, 346. xvi INDEX. Termes (White-ants), Influence on the Roots [ by, 345. Influence on the Soils [ b y. 345 Killing Saplings, 356, Mode of attack, 346. Mud covered ways of, [ 344. 346. prefer the mature wood [ of Stems, 347. Raider, or Under- [ ground form of, 342, 367. reduce the stem to a [ shell, 347- ; , Kound mound forming, , [34i. season of depreda- [ tions, 348-49. Subterranean action [ of, 344- fed form of, Surface hiv ,, Village form, 341, Termitidse, 339 69. Tetranychus bioculatus, 10, 12, 13, 27, 29, [ 3i 372, 373386, 389, 403, 406. T sp., 387. T. telarius, 374. Tezpur, 7, 95, 202, 213, 232, 281, 282, 297, [ 412, 420, 428, 443, 444, 458, 459- Thomson, Mr. J. A., 141, 197, 200, 201, 230, [ 236, 238, 239, 242, 247, 333, 400. Thosea cotesi, 121-22. T. divergens, 223-24. T. recta, 222-23. Thread Blight, see Stilbum nanum. Thrips, The, 337-38. Thunderstorms, 34. Thwaites, Mr., 21. Thyroglypus, 373. Thysanoptera, 337-38. Tiha, 328, 433- Tillage (see Hoeing), 32,5565, 88, 161. Tineid, House-forming, 25254. Tineidae, 24354. Tingkong, 291. Tingri, 6, 41, 5, 293, 4<>7- Tinnevelly, 166. Tiphuk, 4, 232, 233, 236. Tissues, 34,37-38, 70. Tobacco, 360. Top dressing, 409. Tortricidse, 24354. Tortrix, Tea, 248. Tortrix, Bud-involving, 249. Trabala vishnu,23o. Transparent scale Bark Louse, see Aspidiotus [ lataniae. Transpiration (=Breathing and perspiration [ of plants), 36-37, 39, 70. Transplanting, see Seedlings. Travancore, 167. Treatment of Pests, etc., 14, 178. Trichinopoly, 166. Trifolium (= Clover), 168, 174. Trimen, Dr., 269. Triposporium Gardneri (=Black fungus), 27. Tropical Agriculturist, 179. Tropical vegetation, 77. Troup, Mr. Norman F. J., 311. Trying Experiments, 13. Tubercles, see Nitrogen giving Organisms. Tukvar Tea Company, 373, Tun tree, 279. fur, see Cajanus indicus. Turnip Leaf-miner, 257. Tussock Moth. The Indian Tea, see [ Dasychira (Olene) mendosa. Twigs, Useless, I0i. " Two and a bud," 138, 139. Typhlodromus carinatus, 29, 387 93, 401, [ 403, 405, 406, 407, 408. u Ulu, see Imperata. Unhealthy Bushes, 19. Uneven quality and age of leaf, 149. Uniformity of jat, 43, 45. Unproductive Gardens, 20. Unpruned Tea, 25. Uprooting, see Bushes uprooting of. Uraria crinita, 177. Urticating Slug-like Caterpillar, 226228. Utengah, see Dillenia indica. Vacancies, Filling up, 18, 20, 48, 130, 186, L 232, 262, 409. Vedalia cardinalis, 318. Vade Mecum, see Tea Planters'. Vegetable blights, see Blights. Vegetable Parasites, 409, 467. Vegetables, 97. Veins of Leaf, Number of, 15, 49 Ventilation, 25, 92, 412. Vetch (Vicia), 174. Village sites, Abandoned, 12. Vine, 1 86, 465. Vitality, 70-71. Viviparous Reproduction, 275, 301, 312. Voelcker, Dr. J. A., on Drainage, 75, 373. w Walker, Mr., 293. Wallace, Professor, 74. Wallich, Dr., 41. Walsingham, Lord, 243, 249. Wanklyn, Mr., 164. Ward, Professor H. Marshall, 21, 443, 448, [ 459- Wash, Surface, 56, 58-59, 69, 72, 74,. 81, [82,83,86,88,122,156. INDEX. xvii Wasps, see Hymenoptera, 259-60, 319, , [ 372. Wasps Black, 315. Water,33 35, 36, 56, 6672, 76, 82, 418. Water, Superfluous, 66-67. Water, Surplus, 78. Waterhouse, Mr. Chas. O., 328. Waterlogged Soils, 67, 69, 76, 79, 83, 84, [ 87, 88, 107. Watson, Mr., on Hoeing, 59, 60 ; on Drain- age, 73 ; on Shape of Bush, 113, 116; on Plucking, 147. Wax insect, Chinese, see Ericerus pela. Wax insects, Indian, see Ceroplastes ceri- [ fera. Weeding, 409. Weeds, 56-57, 58-59, 61-62, 65, 81, 153, 167, [ 168, 177, 183. Weeds, Foreign, 65. Wells, see Drainage by Wells. Westwood, Professor, 268. Wheats, Pedigree, 42, 52, 01, 93. Whigham, Mr. W. H. C, 261, 342, 348, 350, [ 356, 357. 359> 36o. White-ants, see Termes taprobanes. White-blight, see Cephaleuros virescens. White-Blister, see Exobasidium vexans. Whitechapel Teas, 156. Whitehorn, 465. White-mite, see Typhlodromus carinatus. Wight, Mr. R. Allen, 465. Wild Tea plant, see Tea, Wild. Wilforth, Mr., 169. t Williamson Magor & Co., Messrs., 194, [ 221, 310. Willisford, Mr., 222. Wilson, Mr. Alexander, 275. Wind, Germs carried on, 24. Winged insects and Treatment for, 195. Winsland, Mr. F. E., 351 , 367, 368. Wither Blight, see Stilbum nanum, sp. nov. Withering Difficult, 149. Wokha, 6 Wood, Died, see Stem. Wood, Exposure of in Collar pruning, 103, Wood, Formation of, see Stem. Wood, Maturing of, 132, 134, 154. Wood, Mr., 297. Wood-borer, see Xyleborus fornicatus. Wood-borer, see Zeuzera coffeae. Wood-borers (Cerambycid Beetles), 194. Wood-Mason, Mr. J., 31, 187, 264, 267, 268, 269, 271, 274, 281, 287, 289, 303, 310, 3". 372, 373 374. 375. 376, 377. Woohonce insect, 277. Woodrow, Mr., 340. Wound, see Pruning. Wright, Mr. A. T., 306, 308. Xyleborus despar, 193. Xyleborus fornicatus, 182, 19294. Yellow Bark Louse, see Aspidiotus camel- [liaj. Yellow-mite, The, see Acarus sp. Yield per acre, 139, 145-46, 15. 166- Yielding capacity, 32. Yulefc Co., Messrs. Andrew, 218, 238. Zeuzera coffese, 27, 129, 184, Zigzag stem, 306. Zoller, Mr., 164. Zygenidse, 201. 1 7 20. G. I. C. P. O. No. 322 R. & A. 10-4-98. 1,100. W. B-G. UNIVERSITY OF CALIFORNIA AT LOS ANGELES THE UNIVERSITY LIBRARY This book is DUE on the last date stamped below JAN 13 1948 Form L-9-15m-3,'34 ERN REGIONAL LIE A 001 096 845 1