jB 608 
 .P45 T8 
 iJopy 1 
 
 ^^iteuLimi 
 
 Georgia 
 
 State Board of Entomology 
 
 E. LEE WORSHAM, State Entomologist 
 
 BULLETIN No. 49 
 
 JANUARY, 1918 
 
 PECAN INSECTS 
 
 WILUAM F. TURNER. 
 
 PECAN SCAB 
 
 C. S. SPOONER. 
 
 PECAN DISEASES OTHER THAN SCAB 
 
 C. G. CRITTENDEN. 
 
 Atlanta, 
 
 
 Georgia 
 
Georgia 
 
 State Board of Entomology 
 
 E. LEE WORSHAM, State Entomologist 
 BULLETIN No. 49 JANUARY, 1918 
 
 PECAN INSECTS 
 
 WILLIAM F. TURNER. 
 
 PECAN SCAB 
 
 C. 6. SPOONEB. 
 
 PECAN DISEASES OTHER THAN SCAB 
 
 C. G. CRITTENDEN. 
 
 
 Atlanta, 
 
 Georgia 
 
 '^\ i 
 
GEORGIA STATE BOARD OF ENTOMOLOGY. 
 
 ORGANIZATION. 
 
 HON. J. J. BROWN, 
 Chairman, Commissioner of Agriculture, Atlanta. 
 
 HON. R. C. BERCKMANS, 
 Augusta. 
 
 HON. JNO. A. COBB, 
 
 Americus. 
 
 E. LEE WORSHAM, 
 State Entomologist and Secretary of the Board, Atlanta. 
 
 A. C. LEWIS, , 
 Assistant State Entomologist, Atlanta. 
 
 AV. V. REED, ^ ■ 
 
 Assistant Entomologist, Atlanta. 
 
 . W. W. CHASE, 
 Assistant Entomologist, Atlanta. 
 
 W. F. TURNER, 
 Assistant Entomologist, Thomasville. 
 
 IRA W. WILLIAMS, 
 Cotton Specialist, Atlanta. 
 
 C. A. McLENDON, 
 
 Expert in Cotton Breeding, Atlanta. 
 In Exchange 
 Univ, of Illinois 
 
 AUG 2 193* 
 
CONTENTS. 
 
 FOREWORD 4 
 
 PECAN INSECTS (William F. Turner)— 
 
 Pecan Leaf Case-bearer 6 
 
 Pecan Nut Case-bearer 14 
 
 Cigar Case-bearer ^ 19 
 
 Bu'dworm 21 
 
 Shuckworm 22 
 
 Fall Webworni 24 
 
 Walnut or Pecan Caterpillar 25 
 
 Catoealas 26 
 
 Twig Girdler 26 
 
 Flat Headed Borers 27 
 
 Cossid Borer 28 
 
 Shot Hole and Pin Hole Borers' 30 
 
 Lesser Pecan Tree Borer '_ 31 
 
 Curculio 32 
 
 Hickory and Pecan Weevils 33 
 
 Leaf-Feeding Beetles 34 
 
 Leaf Hopper 35 
 
 Pecan Phylloxera 35 
 
 Pecan Aphis 36 
 
 Spittle Insects 37 
 
 PECAN SCAB (C. S. Spooner) 38 
 
 PECAN DISEASES OTHER THAN SCAB (C. G. Crittenden)— 
 
 Pecan Rosette 44 
 
 Brown Leaf Spot 45 
 
 Kernel Spot ^ ^ 46 
 
 Nursery Blight 47 
 
 Anthracnose , 48 
 
 Crown Gall . 48 
 
 Mildew 48 
 
FOREWORD. 
 
 Pecan growing is rapidly becoming one of the most important in- 
 dustries of south Geoigia and in recent j'^ears more and more plant- 
 ings have been made in the central and even northern portions of 
 the state. At present thousands of acres have been set out to pecans 
 through south Georgia and these plantings are being increased 
 yearly. (Frontispiece.) As a result the growers are already deeply 
 interested in the insects and diseases Avhich attack the pecan, and 
 these pests are of continually increasing importance as the capital 
 which is invested in the business increases. 
 
 The present bulletin is not intended to give exhaustive reports 
 on the life histories of the various insects and diseases which attack 
 the pecan. In fact, workers have been engaged in the study of the 
 insects for such a short time that there are very few of them whose 
 life liistories are thoroughly known yet. This is also true, though 
 perhaps in less degree, of the diseases. 
 
 In view of the numerous requests which are constantly being 
 received for information concerning these matters, it was felt that 
 the situation could best be met by a publication giving a general 
 survey of the field. In the present bulletin, therefore, an attempt 
 has been made to furnish the pecan growers with a guide by which 
 they may become familiar with the insects and diseases Avhich are 
 now injurious, or which may become so, and may further become fa- 
 miliar with the principal methods of control. 
 
 It should be borne in mind that, altho many insects are dealt with 
 in this bulletin, probably only a few of them will ultimately be 
 looked upon as serious pests of the pecan. In this connection it is 
 well to call to mind that man}- fruits, for instance apples, have as 
 many or even more species of insects attacking them. Yet under or- 
 dinary conditions the grower has to contend with not more than three 
 or four. Without doubt this will ultimatel}- be found to be the case 
 with the pecan, also. Those insects Avhich are most injurious at 
 the present time have been indicated, as have those which seem to 
 possess habits and characteristics which may cause them to become 
 of serious importance later. 
 
 With regard to some insects, at least, it has already been proven 
 that successful, commercial pecan culture must include tlie spraying 
 
of the trees. At first this seems a big item— something special which 
 must be done. If the grower, however, will simply include spray- 
 ing in his list of the year's operations, expecting to spray his trees 
 at a certain time, just as he expects to plow at given periods, he 
 will soon find that the matter adjusts itself naturally, and quickly 
 becomes as little of a bug-bear as is planting or cultivating. 
 All dates given in this bulletin are for Thomasville, Ga. 
 
PECAN INSECTS.* 
 
 PECAN LEAT CASE-BEAEEE. 
 
 {Acroiasis neiulella Eiley.) 
 
 This insect is, at ilie present time, one of the most serious ene- 
 mies of the pecan, probably causing more damage, in Georgia, than 
 all other insects together. Fortunately, the species is, thus far, con- 
 fined to south Georgia. It is present in injurious numbers about 
 Thomasville, Cairo, Valdosta, Fitzgerald, Blackshear and Nashville. 
 It has not been found in any numbers in the Albany district, how- 
 ever, and we have no reports of it from central Georgia. Since it 
 has already been present in Florida and south Georgia for several 
 years we have abundant grounds for hope that it will not become of 
 serious importance in regions north of those in which it occurs at 
 the present time, yet so many other insects have demonstrated their 
 ability to adjust themselves to unfavorable conditions, particularly 
 of climate, that it is possible the Pecan Case-bearer may do so event- 
 ually, and become a pest in portions of the pecan belt where it does 
 not occur at present. 
 
 The principal damage is caused in the spring. The insects be- 
 come active at the time when the buds begin to burst. The cater- 
 pillars or "worms" feed voraciously on the opening buds and ten- 
 der shoots, frequently boring into and killing them. Young trees 
 are often stripped entirely and, in bad outbreaks, trees as old as 12 
 and 13 years maj^ be defoliated. This defoliation checks the growth 
 of the trees and destroys the crop for the year. Since the larvae 
 also attack the stems which bear- nuts the crop is frequently de- 
 stroyed even when the damage to the trees is not particularly se- 
 vere.f Later, when the trees are well leafed out and the larvae 
 can no longer feed on buds and young shoots, they attack the 
 bases of the main leaf stalks and the leaflets themselves. This 
 feeding is not as serious as that done earlier in the season. 
 
 *As indicated in footnotes, the portions on tliree or four of the insects were 
 written by Mr. C. S. Spooner, formerly with the State Board of Entomology. 
 
 t Still a third type of injury was noted on one variety of trees, the Young-, in 
 the spring of 1916. Two trees about 30 ft. in height were under observation. Par- 
 ticular notes were made on April 22nd. On these two trees practically all the cat- 
 kins, or male blooms, w^ere destroyed by the worms, which fed at the base ol these 
 catkins. Very little injury of any other sort was noticed on these two trees. On 
 trees of other varieties, near the two trees in question, little or no injury to the 
 catkins was observed but the larvae were feeding, as is their usual habit, at the 
 bases of the main leaf stalk and on the leaves themselves. The crop of these two 
 trees was a failure. 
 
LIFE HISTORY AND HABITS. 
 
 The adult insect is a mottled grey moth which, when its wings 
 are spread, measures about five-eighths of an inch, across. (Plate I, 
 fig. 1.) When at rest it has a ha:bit of sitting on a small twig with 
 its head raised, the body forming an angle of about 30° with the 
 twig and this position, together with the coloring, makes it very 
 difficult to see. (See cover.) It seldom flies during the day time, 
 but is very active at night. 
 
 Egg laying commences about the first of June and a few moths 
 may lay as late as the first of August. The majority of the eggs are 
 laid from about the middle of June to about the end of the first week 
 in July. These eggs are small, soft, semi-transparent objects and 
 are laid, almost invariably, along the main rib, on the under side 
 of the leaf. In rare cases they are laid in angles between the side 
 veins and one of the largest of the veins which branch off from 
 these. We have never found eggs anywhere except on the under 
 surface of the leaves. 
 
 The eggs hatch in a few days. This hatching commences, at 
 Thomasville, about the middle of June and continues into early 
 August. Most of the eggs hatch, however, during the first three 
 weeks in July. 
 
 The young larvae, or "worms," are very small and usually red- 
 dish brown in color. They immediately commence feeding, eating 
 only the lower surface of the leaf. From the frass and excrement 
 they form a little tube, spinning silk with which to bind the parti- 
 cles together and line the case. This case is attached quite firmly 
 to the leaf and runs along on the under surface of it. Commencing 
 at the spot where the egg was laid the larva feeds outward, work- 
 ing back and forth so that the spot is fan shaped. The upper sur- 
 face of the leaf turns brown. As the larva feeds it builds its case out- 
 ward. The case itself is very firmly and tightly made, but at the outer 
 end the larva builds a loose fan-shaped tent, under which it feeds. As 
 soon as it eats all the green which it can reach from this tent it 
 draws the back portion of it together, prolonging the case, or tube, 
 and extends the outer portion in such a manner as to cover more 
 .green leaf. Since it also moves back and forth across the edge 
 of the spot on which it has fed the case is curved, S-fashion, and 
 
finally, by fall, becomes very serpentine in form. (Plate II, fig. 2.) 
 From one to twenty or more eggs may be laid on a single leaf. 
 Each larva consumes only a small portion of the surface, usually 
 Remaining between the side rib near which the egg was laid, and 
 the next one toward the tip. A larva may cross one of these side 
 ribs, however, and while it usually feeds outward toward the tip, 
 an occasional worm will turn back toward the base of the leaf. 
 The feeding spots are very noticeable from both the upper -and 
 lower surfaces and in cases of severe outbreaks infested trees can 
 be picked out from a considerable distance. Some of the larvae 
 die during the summer, especially when there are several eggs laid 
 on one leaf. Such larvae can always be located during the late 
 summer and early fall, from the fact that the feeding spot is small 
 and the end of the case does not reach to the edge of the brown 
 spot. The tent usually is missing or the case may have been 
 broken off entirely. 
 
 This summer feeding of the larvae is not particularly serious, in 
 itself, except in the case of very severe outbreaks on young trees, 
 when the growth of the trees is checked somewhat. As has been 
 said, each worm does not eat very much and since the leaves are 
 hard and do not furnish much nourishment, especially toward the 
 end of the summer, the larva grows very slowly indeed, being only 
 about one-twentieth of an inch long when it is obliged to cease 
 feeding in the fall. The importance of this period lies in the fact 
 that, up to the present, we have found' it the best time to control 
 the insect, as will be shown later. 
 
 In the fall, shortly before the leaves drop, the little worms leave 
 their cases and crawl down to the buds. Here they form tiny, 
 round, flattened cases, called hibernacula, and in these they spend 
 the winter. (Plate II, fig. 1.) The hibernacula are most fre- 
 quently located in the little groove where the bud touches the twig. 
 When abundant, however, they may be anywhere about the bud, or 
 even on it. As has been intimated, there is a close connection 
 between the time of this migration and the time when the leaves 
 drop. At Thomasville, in 1916, the migration began late in Sep- 
 tember and continued till frost, on November 16th. On October 
 24th, observations showed that about 50% of the insects had left the 
 leaves. The migration commenced earlier on Mobiles than on any 
 
FRONTISPIECE. 
 
 
 
 
 Map showing the distribution of pecans, by counties. Each dot 
 represents 100 trees. The actual distribution of the trees in each 
 county is not shown. (Figures from the 19th Ann. Rept. of the 
 State Entomologist.) 
 
rLAT^ L 
 
 Fig. 1. Leaf Case-Bearer. 
 
 Fig. 2. Nut Case-Bearer. 
 
 FiT. 3. Cossid moth. 
 
 Fig. 4. Bud worm. 
 
 Fig. R Fall web-worm. 
 
 Adults of some Pecan Insects. (Slightly enlarged.) 
 
PLATE II. 
 
 Fig. 1. Pecan Case-Bearer. Win- 
 ter cases on bud. (Enlarged.) 
 
 Fig. 2. Pecan Case-Bearer. Sum- 
 mer cases. (July 15.) (Enlarged.) 
 
 Pig. 3. Pecan Case-Bearer. Spring cases on 
 main leaf stalk. (Natural size.) 
 
PLATE III. 
 
 Fig. 1. Pecan Leaf Case-Bearer. Late spring feeding. 
 
 Fig. 2. Pecan Leaf Case-Bearer. Early spring feeding on opening buds. 
 
9 
 
 other variety, Mobiles shedding their leaves before the other com- 
 mon varieties do. Thus, on October 1, 1916, many hibernacula 
 were found about the buds of the Mobiles, while none were found 
 on other varieties. 
 
 The little larvae spend the winter in the cases on the buds, 
 only leaving them in the spring at about the time the buds begin 
 to burst. They then commence feeding on the opening buds and 
 tender shoots, often boring into them. (Plate III, fig. 2.) A new 
 type of case is now formed, this being the case most commonly 
 noticed by the growers. It is cylindrical, open at both ends, and 
 is carried about by the worm, as it moves from place to place, al- 
 ways standing out from the surface on which the worm is feeding. 
 The young larva sometimes leaves one case entirely, building a 
 new one in another location. When the larva bores into a shoot 
 it usually fastens the case at the entrance of its burrow with silk, 
 sometimes feeding with part of its body in the case and part in the 
 burrow, at other times with its body entirely inside the burrow. 
 At first the color of the case is a dirty grey, most of the outside 
 being composed of frass. Later, when the larva is nearly full grown, 
 more silk is used on the outside till finally the case is a light, sil- 
 very grey in color. It is always lined with silk. These mature 
 cases are nearly always found out on the leaf stalk or on the 
 under side of one of the leaflets themselves. (Plate II, fig. 3.) 
 
 The worms grow very rapidly at this time, becoming, when 
 full grown, about three-fourths of an inch in length, while the 
 case is about one inch long. The larva varies from a reddish 
 green to olive green, the color depending somewhat on the por- 
 tion of the tree on which the worm has been feeding. 
 
 When the larva is full grown and ready to pupate, it almost 
 invariably fastens its case on the main stalk of a leaf, between two 
 leaflets. These it draws together, fastening them loosely to the 
 case and to each other with silk. It then builds two silken flaps, 
 or lips, at the outer end of the ease. These press together in such 
 a manner that they cannot easily be opened from the outside, since 
 any pressure simply closes them more tightly. On the other hand a 
 very slight pressure from within will open them easily. 
 
 The larva now rests in its case for a few days and then pupates, 
 with its head toward the outer end of the case. This pupal stage, 
 
10 
 
 the period during which it transforms from a worm to a moth, lasts 
 on the average for about 16 or 17 days. In 1914, the period lasted, in 
 two cases, only 14 days, while one insect required as much as 20. 
 This pupal period commences about the middle of May, a few 
 insects probably pupating even earlier. It continues as late as the 
 first of July. At the end of this period the moths emerge and are 
 soon ready to lay the eggs for another generation. 
 
 CONTBOIi. 
 
 Up to the present time the only successful method which has 
 been discovered for controlling this pest is to spray the trees with 
 arsenate of lead between the middle of August and the last of 
 September. All attempts to control with arsenate of lead in the 
 spring have failed. This is also true of efforts to kill the worms in 
 the winter cases by spraying during the winter with lime-sulphur. 
 
 The formula which we would now recommend is as follows.: 
 
 Arsenate of lead (powdered)* 1 lb. 
 
 Lime 2 lbs. 
 
 Fish oil soap 2 lbs. 
 
 Water 50 gals. 
 
 The lime is added to this mixture in order to prevent the ar- 
 senate from burning the foliage. "When it is not used the trees 
 may be quite seriously injured. The soap is not absolutely nec- 
 essary but its presence makes the spray mixture spread much more 
 readily and evenly and, during the season of 1916, it was found 
 that mixtures which contained the soap adhered to the foliage 
 somewhat better than did those without it. 
 
 In groves of young trees, up to five or six years of age, an or- 
 dinary barrel pump may be used. In the older groves, however, 
 the most satisfactory results can only be obtained by the use of a 
 power sprayer. (Plate IV, figs. 1 and 2.) 
 
 The most important point to remember is that the trees must be 
 thoroughly sprayed. While it requires only a very minute quan- 
 tity of the poison to kill the tiny worm it is absolutely essential that 
 that poison shall be placed where the worm will reach it. Therefore, 
 for good re sults, care must be taken that, in so far as is possible, the 
 
 *If arsenate of lead paste is used, the amount must be doubled; that is, 2 lbs. to 
 50 gals, of water. 
 
11 
 
 under side of every leaf is covered with the material. If this is 
 done the grower will have no trouble in controlling this pest. 
 
 WINTER SPRAY. 
 
 Growers frequently ask why winter spraying cannot be em- 
 ployed against this pest. Several experiments have been con- 
 ducted in which the trees were sprayed with lime-sulphur, and 
 during the winter of 1916-17 we made extensive tests, using lime- 
 sulphur, miscible oils and home-made oil emulsions. These sprays 
 were absolute failures. The same was true of sprays containing 
 nicotine sulphate and soap, applied in the spring just at the time 
 the larvae were leaving their winter cases to commence feeding 
 on the buds. Apparently the hibernacula are so tightly woven 
 that the spray materials do not penetrate them thoroughly. The 
 failure of the spring treatment to produce any appreciable effect 
 seems to be due to the fact that no one time can be selected when 
 a large enough percentage of the "worms" are exposed to the poison. 
 
 NATURAL ENEMIES. 
 
 There are several natural enemies which aid in controlling the 
 Leaf Case-bearer. These consist of parasites, including several 
 species ef minute wasps,* and at least one fly;t predaceous ene- 
 mies, including two or three species of bugs which attack the larvae 
 and suck out the juices; and birds, as blue jays, which tear open 
 the cases and pick out the "worms." 
 
 Rather limited examinations in one grove, during the season of 
 1916, gave the following results: 8.7% of the larvae in the cases 
 collected were destroyed by parasites; 12% had been killed by 
 birds, while 14.2% were "sick." Some of these "sick" larvae may 
 have contained parasites but this point was not definitely settled. 
 
 In 1917, several- lots of cases were collected from five groves 
 at various intervals between May 18th and July 27th. These 
 were examined carefully and the results are recorded in the fol- 
 lowing table : 
 
 •Habrobracon variabilis Cush.. Macrocentrus sp., Exochus apicalis Cr. Several 
 other species were reared in 1917, but these have not yet been determined. 
 tExorista pyste Wlk. 
 
12 
 
 Table 1— Percentage of Worms Killed by Natural Causes. 
 
 
 Total 
 Cases 
 
 Parasites 
 
 Killed by Birds 
 No. % 
 
 Dead & Dried 
 
 Total Dead 
 
 Grove 
 
 No. % 
 
 No. 
 
 % 
 
 No. 
 
 %■ 
 
 I 
 
 304 
 
 27 • 
 
 8.8 
 
 5 
 
 1.6 
 
 9 
 
 2.9 
 
 41 
 
 13.4 
 
 II 
 
 365 
 
 24 
 
 6.5 
 
 8 
 
 2.2 
 
 15 
 
 4.1 
 
 47 
 
 12.9 
 
 III 
 
 614 
 
 18 
 
 2.9 
 
 12 
 
 1.9 
 
 27 
 
 4.4 
 
 57 ■ 
 
 ' 9.2 
 
 IV 
 
 90 
 
 15 
 
 16.6 
 
 4 
 
 4.4 
 
 4 
 
 4.4 
 
 23 
 
 25.5 
 
 V 
 
 50 
 
 7 
 91 
 
 14.0 
 
 2 
 
 4.0 
 
 1 
 
 2.0 
 
 10 
 
 20.0 
 
 Ttl. 
 
 1423 
 
 
 31 
 
 
 56 
 
 
 178 
 
 
 Avg. 
 
 
 
 6.4 
 
 
 2.1 
 
 
 3.9 
 
 12.5 
 
 In view of the fact that extensive examinations, including sev- 
 eral thousand individuals, have shown that there may be a total 
 annual mortality of nearly 95% of this species, due mainly to the 
 fact that large numbers never form eases on the buds, while many 
 also die during the winter, and that in spite of this the species 
 caused severe injury to the very groves in which the data was 
 obtained, it is evident that little can be hoped for in the way of 
 control by either parasites or birds. 
 
 Some very interesting data were obtained during the past sea- 
 son on the value oi a predaceous bug, Arilus cristatus, in the con- 
 trol of the Leaf Case-bearer. Three bugs ate a total of 76 
 "worms" between May 11th and June 5th. At this latter date 
 other food had to be provided since no more Case-bearer larvae 
 were available. The larvae were removed from their cases before 
 being fed to the bugs, so these figures must be considerably in 
 excess of those actually obtaining in the field, where the bugs are 
 obliged to search for the "worms" and to attack them in their 
 cases. They indicate, however, that this species may be of con- 
 siderable benefit wherever it occurs in any numbers. As with the 
 parasites and birds, however, predaceous bugs cannot be relied on 
 to control the pest and wherever Case-bearers are abundant arti- 
 ficial means of control must be employed. 
 
13 
 
 VARIETIES OF PECANS ATTACKED. 
 C. S. SPOONER. 
 
 There is another most interesting point in connection with this 
 insect and that is the freedom from attack enjoyed by many varie- 
 ties of pecans. This is very evident and easily observed. In the 
 same grove with trees of different varieties planted next each other, 
 the one will be heavily infested and the other almost free from 
 attack. 
 
 It was first noticed that the large leaved varieties were most 
 subject to attack, while the small leaved varieties were, to a large 
 extent, free from the insects. Further examinations showed the 
 probable reason for this. It will be remembered that the eggs of 
 this insect are laid in the angles made by the secondary veins with 
 the midrib. Now in the large leaved varieties the veins are also 
 large and form a deep pocket at this angle. In many cases the 
 entrance to this pocket is hidden by hairs. This forms an ideal 
 place for the eggs of the Case-bearer. They are hidden and pro- 
 tected from weather. The small leaved varieties lack these pockets 
 and the egg must be laid directly on the surface of the leaf. There 
 is little doubt but that the presence of this pocket favors the at- 
 tack of these insects. The moths would search for them in prefer- 
 ence to depositing their eggs on the small leaved varieties. 
 
 Notes were taken on the numbers of Case-bearers found on the 
 different varieties. Trees in the same groves were compared and the 
 insects were there in sufficient numbers to seriously infest all the 
 trees, had they not selected the varieties most suitable to them. 
 The following varieties were severely infested : 
 
 Capitol, ^ Frotscher, 
 
 Van Deman, Taylor, 
 
 Schley, Alley, 
 
 Nelson, Appomattox, 
 
 Stuart, Delmas. 
 
 The following list had very few of the Case-bearers on them: 
 
 Money-maker, Mantura, 
 
 Hassen, Hican (none), 
 
 Georgia, Teche, 
 
 Curtis, Young. 
 
 Russell, 
 
14 
 
 The following varieties seemed to be intermediate between the 
 above two groups: 
 
 Mobile, Senator, 
 
 Creole, Teddy, 
 
 Success, Bacon, 
 
 President, Hadley. 
 
 Pabst, 
 These lists do not by any means include all the varieties, but 
 are simply those which have been under observation. 
 
 The question may arise as to whether freedom from the at- 
 tack of this insect .should be considered in selecting varieties for 
 planting. In cases where the varieties are about equal in other 
 desirable points it would be well to let this point influence your 
 choice. This insect is, however, so readily controlled that the free- 
 dom from attack would not outweigh any serious faults in a va- 
 riety. 
 
 PECAN NUT CASE-BEARER. 
 
 (Acrobasis liebescella Hulst.) 
 
 The Pecan Nut Case-bearer is a comparatively recent comer to 
 Georgia, having been here for probably only four years, or five 
 at the most. It has been in Florida for a somewhat longer period 
 and is of quite common occurrence west of the Mississippi, where it 
 appears to be native. As far as we know, in Georgia the species 
 is now confined to groves about Thomasville and Cairo, though it 
 may occur elsewhere along the southern edge of the state. This in- 
 sect, as its name indicates, is particularly an enemy of the nuts, 
 themselves, altho in certain stages it attacks the shoots and swollen 
 bases of the leaf petioles. 
 
 While the Nut Case-bearer is not of great economic importance 
 in Georgia at present, because of its very limited occurrence, it 
 seems very possible that it may eventually become our most se- 
 rious pecan enemy. In one grove near Thomasville, during' 1916, 
 the worms destroyed 50% of the crop on the Frotscher trees and 
 over 35% of the Teche before June 20th. The species always 
 causes most of its damage early in the season, as will be explained 
 later, but the total damage to the grove for the year was un- 
 doubtedly as much as 50%, including both varieties. 
 
15 
 
 LIFE HISTORY AND HABITS. 
 
 Unlike the Leaf Case-bearer, this species has three generations 
 during a single year. It spends the winter as larvae in hiber- 
 nacula attached to the buds, just as does the Leaf Case-bearer, 
 The larvae, or "worms," leave these winter cases as soon as the tree 
 commences growth in the spring, and complete their growth by 
 boring into the new shoots and feeding within them. The larvae 
 look very much like those of the Leaf Case-bearer, varying in color 
 from a yellowish brown through various shades of greenish brown 
 and greenish grey to a pinkish olive green. The head and tho- 
 rasic shield are dark brown. These larvae become full grown and 
 pupate about the first of May and the moths begin to emerge and 
 lay eggs about the middle of the month, at Thomasville. 
 
 The moths are about the size of the Leaf Case-bearer moths. 
 Their fore wings are darker in color with a ridge of black scales 
 at the base of each wing. When the wings are folded these ridges 
 give the moth a hump-backed appearance. The hind wings are 
 lighter grey. The abdomen is grey while the head and thorax 
 have a more brownish cast. (Plate I, fig. 2.) 
 
 The eggs, which are very small and greenish or pinkish white 
 in color, are laid at the blossom end of the newly formed nutlets, 
 which at this time are about one-fourth to one-half of an inch in 
 length, depending on the variety. These eggs hatch in a very 
 few days and the tiny "worms" crawl down to the bases of the 
 nutlets and bore into them, usually close to the line where the 
 nut is attached to the stem, although occasionally entrance holes 
 are found elsewhere on the nuts. 
 
 The young worm usually hollows out the nutlet ifi which it is 
 feeding, eating out the portion which would later become the nut 
 and leaving the portion which would eventually become the husk. 
 Having finished one nutlet it leaves it and attacks another in the 
 same cluster. Occasionally the larva migrates to a second nut be- 
 fore it has eaten very much in the first. One larva may feed on as 
 many as four or five nuts before reaching its full size and it is for 
 this reason that the damage is so severe at this time of the year. 
 The hollowed nutlets soon turn brown and dry and may be seen 
 hanging from the stems by threads of silk used by the worms in 
 
16 
 
 making their cases. These empty nuts frequently hang on the 
 trees throughout the season. 
 
 After becoming half grown, or even sooner, the larva usually 
 builds a short tube or case, perhaps one-sixteenth to one-eighth 
 of an inch in length, about its entrance hole. (Plate V, fig. 1.) 
 This is formed of silk and frass. Frequently a worm will also 
 build a tube from the base of the nut on which it has been feed- 
 ing to the base of the next one which it attacks and these tubes 
 may be one-half an inch or more in length. This habit, together 
 with its feeding habits, suggested the name of Pecan Nut Case- 
 bearer.* 
 
 In the laboratory the first larva reached full size, in 1916, about 
 June 6th, and one had pupated by June 9th. The great majority 
 of the insects had pupated by June 24th. The larva when pre- 
 paring for this stage faces with its head towards the entrance bur- 
 row and transforms within the little nut which is just about large 
 enough to hold the pupa. The moth emerges through the entrance 
 burrow, which is of good size. This is due to the fact that the in- 
 sect pupates, of course, in the last nut attacked and that the 
 "worm" was nearly grown when it entered this nut. 
 
 The first adult emerged, in the breeding cage, on June 18th in 
 1916. In 1917 moths appeared as early as June 10th. Emergence 
 continued till July 9th, 1916, and to July 12th, 1917. 
 
 These moths, in turn, lay eggs at the blossom ends of the nuts, 
 which are much larger now, being fully half or more than half 
 grown. Each "worm" feeds only in one nut, and does not clean 
 that one out. As a result each larva of this generation destroys 
 only about one-fourth as many nuts as does a larva of the first 
 generation. (Plate V, fig. 2.) 
 
 The entrance burrow is still made near the base of the nut. 
 Since it is made by the worm just after it has hatched it is usually 
 very small and in many instances there is no case about it. Also the 
 adult frequently cannot emerge through it and consequently in 
 such cases another method for emergence is provided. Before it 
 pupates, the larva eats a hole almost through the husk of the nut, 
 leaving just a thin layer of the surface, to cover it. This hole is 
 usually in the side of the nut near the base. The larva then forms 
 
 *This name was suggested by Mr. A. C. Gill, of the U. S. Bureau of Entomology. 
 
PLATE IF. 
 
 Pig. 1. Spraying for Case-Bearer. Using a Bordeaux Nozzle on one line, 
 so that the tower is not needed. 
 
 Fig. 2. Pilling tank from a well, by means of a barrel. 
 
PLATE V. 
 
 Fig. 1. Work of first generation on small nuts. 
 (Much enlarged.) 
 
 Fig. 2. Work of second generation on nearly 
 grown nuts. (Slightly enlarged.) 
 
 M 
 
PLATE VI. 
 
 Fig. 1. aunimer case 
 (much enlarged). 
 
 Fig. 2. Winter case 
 near bud. 
 
 Fig. 3. Summer case on leaf; note dark 
 area, where insect has fed. 
 
 Cigar Case-Bearer. 
 
PLATE III. 
 
 Fig. 
 
 1. Web-worm moth 
 covering eggs. 
 
 Fig. 
 
 Same e^s hatch with 
 moth removed. 
 
 Fig. 3. Egg batch of wahiut, or pecan, catcrijilkir. 
 
17 
 
 a cocoon of silk and frass, with the head end open and attached 
 about the exit hole. It pupates in this cocoon and later trans- 
 forms into a moth. This moth simply pushes out the flap and 
 escapes. 
 
 The nuts attacked by the second generation seldom hang on 
 the trees as do the nuts attacked by the first, since they are much 
 heavier and are not held by silk. They frequently drop before 
 the moths have emerged, and the worms complete their feeding 
 and transform to adults in these nuts on the ground. 
 
 The second generation pupated between August 3rd and 20th, 
 1916, mostly about August 16th. Moths began emerging about 
 August 15th and apparently all had emerged by about September 
 1st. In 1917 one moth emerged as early as August 10th. 
 
 The larvae of the third generation feed little, if at all, on the 
 nuts. Instead they attack the swollen bases of the leaf stems, 
 feeding in these until it is time for them to form their winter 
 cases on the buds. It will be noticed that the 'Svorms" of this 
 generation feed on leaf and stem tissue throughout their entire 
 life (both in the fall and spring), while those of the other two 
 generations feed on nuts. 
 
 CONTROL. 
 
 We have not conducted any experiments, as yet, for the par- 
 ticular control of this species, for this reason. During 1916 one 
 grove, rather severely infested with Leaf Case-bearers, was sprayed 
 as recommended, with arsenate of lead, between August 22nd 
 and 25th. In 1916 fully 50% of the nuts in this grove were de- 
 stroyed by the Nut Case-bearer. In 1917 this species destroyed 
 only 5.8% of the nuts on the worst infested tree in the grove. 
 These results seem to indicate that the spray used for the Leaf 
 Case-bearer, if applied at the proper season, will also control the 
 Nut Case-bearer. However, this cannot be definitely stated, since 
 another factor, to be mentioned below, complicates the situation 
 and may be sufficient of itself to account for these results. This 
 decrease in infestation further precluded the possibility of control 
 experiments in 1917, as no groves were found in which the in- 
 sects were present in sufficient numbers to furnish reliable data. 
 
 As previously^ noted, winter spraying with various materials 
 
18 
 
 has not yet proven efficient against the Leaf Case-bearer, and 
 cannot be expected to be any more so against this insect. 
 
 NATURAL ENEMIES. 
 
 The natural enemies of this species appear to control it more 
 efficiently than is the case with any other important insect at- 
 tacking pecans. To return once more to the grove already men- 
 tioned as losing half of its crop through the work of the Nut Case- 
 bearer, during 1916, it was found that 50% of the first generation 
 was destroyed by parasites. Of these there were reared two spe- 
 cies of Hymenoptera,* which together killed 23.5%, and one Dip- 
 teron,t or fly, which accounted for 26.5%. As will be seen, this 
 is the most important of the enemies of the Nut Case-bearer as yet 
 recorded. This fly also attacks the Leaf Case-bearer to some ex- 
 tent. 
 
 As a result of this parasitism the second generation was much 
 less abundant than the first. The percentage of "worms" de- 
 stroyed in this way was also less, in the second generation, but still 
 about 10% to 12% were killed. This difference is probably due, 
 for the most part, to the fact that the larvae of this generation 
 live entirely in a sheltered position, while those of the first gen- 
 eration are frequently exposed, when migrating from one nut to 
 another and before they are able to burrow within each new nut, 
 thus giving the fly, which is the most important enemy, an oppor- 
 tunity to lay its eggs on them. 
 
 In 1917, as stated in the discussion on control, the infestation 
 in this same grove was only nominal, one tree, the most severely in- 
 fested, losing only 5.8% of its nuts, and the damage to the entire 
 grove being about 1%, or less. Since this grove was sprayed, in 1916, 
 at about the time the young larvae began to attack the bases of the 
 leaf stems, many of them may have been killed by the spray. Never- 
 theless, the results for the early part of 1916 indicate that parasites 
 exert an important influence on the abundance of Nut Case-bearers. 
 
 In 1917, of the insects handled in breeding cages, 17.3% of the 
 first generation were destroyed, 13% by the fly and 4.3% by the 
 
 *Habrobracon variabilis Cush., Mlcrobracon sp. Other species reared In 1917 
 have not been determined. 
 tExorista pyste Wlk. 
 
19 
 
 wasp parasites. As a result the second generation was not at all 
 abundant, only an occasional infested nut being found. 
 
 Growers should bear in mind the fact that parasites are al- 
 most never entirely satisfactory as a means of control of in- 
 jurious insects. They never absolutely destroy their host insect, 
 as to do so would be to starve themselves to death. However, 
 during years when the host insect is scarce, great numbers of the 
 parasites cannot find food and consequently die. Thus they be- 
 come scarce, in their turn, and the host insects being almost free 
 from enemies begin to increase in numbers, rapidly, the parasites 
 also becoming more numerous as their food insects become abun- 
 dant, but never quite catching them. Finally there is a climax year 
 when the pest is extremely abundant and injurious, at first, while 
 the parasites are also abundant, and finally destroy a large per- 
 centage of the injurious form. As a result the pest will be scarce 
 the next year and the parasite, abundant at first, will themselves be- 
 come more and more scarce as their food becomes harder and 
 harder to find, till they too are rare, and the whole cycle begins 
 over again. 
 
 It is for this reason that insects having important insect ene- 
 mies, such as is the case with army worms, are abundant only pe- 
 riodically. This will undoubtedly prove true with the Nut Case- 
 bearer and consequently it will probably be necessary to supple- 
 ment the work of parasites by artificial control during some sea- 
 sons. 
 
 VARIETIES OF PECANS ATTACKED. 
 
 Very little has been noted on this phase of the problem. In 
 the spring of 1917, however, in a grove containing Frotscher, 
 Teche and Alley, it was observed that a few infested nuts were 
 to be found on almost every Frotscher before any could be located 
 on Alley or Teche. Later, however, the two latter varieties were 
 attacked slightly. 
 
 THE CIGAE CASE-BEAEER. 
 
 CColeophora caryaefoliella Clem.) 
 
 This insect is a leaf feeder like the Leaf Case-bearer. It is a 
 much smaller insect than the latter, the adult being a small, shiny 
 
20 
 
 brown moth, which, with its wings spread, measures something 
 under half an inch across. The wings are very narrow with a 
 thick fringe of long hairs on the hind margins. The case is en- 
 tirely different from that constructed by the two case-bearers which 
 have already been discussed, in that the latter construct a case, 
 bit by bit, from particles of frass bound together with silk, while 
 the Cigar Case-bearer makes its case of pieces of leaf, fastened 
 and lined with silk. (Plate VI, fig. 1.) 
 
 While this insect is widely spread throughout the pecan belt of 
 Georgia it has not been found, as yet, in sufficient numbers to cause 
 serious damage. Infestations have been observed in Florida, how- 
 ever, where the damage was very severe. 
 
 The life history of the insect is very similar to that of the Pecan 
 Case-bearer. The young larvae spend the winter in small cases 
 around the buds, usually in the angle between the bud and the 
 twig. (Plate VI, fig. 2.) In the spring, when the buds swell, they 
 leave their nesting place and feed upon the buds, destroying them. 
 Later they feed on the leaves. When feeding on the leaves the 
 larva mines into the leaf, eating out the interior, but leaving the 
 upper and under surface intact. In doing this it fastens its case 
 at a right angle to the leaf and makes a small hole through the 
 surface, directly under the mouth of the case. It then eats out 
 the interior of the leaf in every direction, as far as it can reach. 
 Having exhausted one spot it moves its case to a new place and 
 repeats the operation. (Plate VI, fig. 3.) 
 
 The insects pupate during the first part of May and the adults 
 emerge the last of May and the first of June. The eggs are laid on 
 the leaves, during the middle and latter part of June. Upon 
 hatching the larvae mine into the leaves and spend some time 
 there, entirely between the two surfaces. They then cut out the 
 dry brown portions of the leaf, tie them together into a case and 
 move about, feeding as previously described. In the fall they mi- 
 grate from the leaves to the buds where they attach themselves for 
 the winter. 
 
 This insect seldom does sufficient damage to warrant control 
 measures. In case of local severe outbreaks we would recommend 
 spraying the trees with arsenate of lead, in the spring, using the 
 formula given for the control of the Leaf Case-bearer. 
 
21 
 
 THE PECAN BUDWOEM. 
 
 (Proteopteryx bolliana Sling.) 
 
 Altho it attacks trees of all ages to some extent, the budworm 
 is particularly a pest of nursery trees and of trees newly set in 
 groves. Like many other pests, while it occurs throughout the 
 pecan growing region of Georgia, it very seldom is present in suf- 
 ficient numbers to cause serious injury. 
 
 This species spends the winter in the adult, or moth stage, hiding 
 under loose bark or elsewhere about the fields. The moth is about 
 the size of the Leaf Case-bearer moth, measuring about five-eighths 
 of an inch with the wings spread. The general color of the front 
 wings is grey mottled in a very pretty pattern with black, while 
 the hind wings are dark grey without markings. (Plate I, fig. 4.) 
 These moths are very abundant in the fall, especially during No- 
 vember, when they may be found resting on the trunks and larger 
 branches of the trees. If disturbed they fly only a short distance, 
 perhaps four or five feet, returning immediately to the same tree. 
 
 The larvae are greenish white in color, with black head and 
 thorasic shield when young — these becoming dark brown in the 
 older larvae. The full grown worm is about five-eighths of an inch 
 long. These grown larvae of the first generation usually leave the 
 bud and migrate to the trunks, where they pupate under loose 
 bark. This habit seems to be very strongly ingrained, since in at 
 least one instance under observation the larvae were forced to 
 travel more than thirty feet from foliage to trunk, which they did in 
 large numbers. 
 
 There are at least five generations of this species in South Geor- 
 gia. The later generations, not having the new and tender shoots 
 to feed on, pick out the youngest foliage present on the trees. 
 This is particularly noticeable during the late summer when the 
 trees put on their second growth. At this time the work of these 
 worms, which has been scarcely noticeable for two or three months, 
 becomes very evident again. In feeding on the foliage the larva 
 folds over the edge of the leaf, fastens this loosely with silk and 
 feeds within, or at the ends of this fold. These larvae do not mi- 
 grate to the trunk for pupation, as do those of the first generation, 
 but transform within the folded leaflet. 
 
22 
 
 CONTROL. 
 
 Under ordinary conditions no control measures are required 
 against this pest. In severe local outbreaks, however, it would 
 be well to spray the trees with arsenate of lead in the spring. 
 
 PECAN SHUCKWORM. 
 
 {Laspeyresia (Enarmonia) caryana Fitch.) 
 
 This insect occurs throughout the pecan belt of Georgia. While 
 it is not found in injurious numbers in all localities, practically no 
 grove in the state is entirely free from it, and it may become serious, 
 during some seasons, wherever it occurs. 
 
 The young, or larvae, burrow in the outer shucks, or husks, of 
 the pecan nuts. The damage is of two sorts. If the insects at- 
 tack the young nuts these fail to develop. If they attack the larger 
 nuts they may fail to fill out, so that when gathered they contain 
 merely a shriveled kernel. The principal injury to the large nuts, 
 however, consists in staining the shell with dark blotches. This 
 materially reduces the market value of nuts. Considerable trouble 
 is caused also by the fact that the infested husks often stick to 
 the nuts and must be removed by force. 
 
 The life history of this species is not completely known, at 
 present, but enough is known to suggest a sure method for sup- 
 pressing the pest, as will be shown later. The larvae spend the 
 winter in the shucks, on the ground. Toward spring, that is in the 
 latter part of February and through March, they pupate, or go into 
 the resting stage during which they change from the worm to the 
 adult moth. This stage, also, occurs in the husk of the nut. The 
 insects become adult and emerge from the husks early in the 
 spring. A few have been reared as early as March 22d (1914) and 
 emergence may continue at least as late as April 28th (1916). The 
 time of greatest emergence was from April 7th to 14th in 1914, and 
 from April 3d to 10th in 1916. The adult is a small moth about one- 
 half to five-eighths of an inch across, when the wings are spread. 
 The color is mottled brown and bronze. 
 
 In the early spring, when the moths of the overwintered gener- 
 ation appear, the nutlets have not yet been formed and the activ- 
 
23 
 
 ities of this species during the weeks intervening between the 
 emergence of the moths and the appearance of larvae in the young 
 nuts have not been definitely determined. It had been thought 
 that the larvae might attack the young shoots, but whether or 
 not such is the case we have not been able to determine as yet.* 
 
 Beginning in late June the larvae of this species are found at- 
 tacking the nuts. These larvae are creamy white in color, with 
 light brown heads. They feed on the husk, or shuck, of the nuts 
 and during the early part of the season, before the nut shell is hard- 
 ened, they frequently eat into the nut itself. Moths again appear 
 in August. These lay eggs on the nuts or leaves and from these 
 hatch out the worms found in the shucks at gathering time. These 
 worms are not full grown when winter arrives but continue their 
 feeding in the shucks on the ground till about midwinter or even 
 later, when they pupate, as noted previously. 
 
 CONTROL. 
 
 The best method of control is to gather and burn the shucks 
 when the nuts are harvested in the fall. This is an economical and 
 very effective method of reducing the numbers of the pest. If 
 the nuts are beaten from the trees on to large sheets, laid on the 
 ground, the nuts can then be picked out and the shucks gathered 
 and put into racks and carried off to be burned. In this way a 
 very large per cent of the insects will be destroyed. 
 
 Late fall plowing will also prove effective. Experiments have 
 shown that 75 to 80% of the insects buried to a depth of three inches 
 will be killed and over 95% of them killed when covered to a depth 
 of six inches. Pasturing hogs in the groves during fall and winter 
 will undoubtedly be beneficial, also. 
 
 NATURAL ENEMIES. 
 
 Parasites have been reared in considerable numbers from this 
 insect, t The percentage of parasitism is often very high, altho 
 there is no present indication that natural enemies will control the 
 pest sufficiently to warrant stopping the artificial measures men- 
 tioned abovCi 
 
 •Gill states, in a recent bulletin, that these first generation larvae probably at- 
 tack pig nuts and hickory nuts, for the most part, only a small percentage of the 
 latest moths to emerge, waiting for pecan nuts. fGill, J. B., Farmer's Bulletin 843, 
 U. S. D. A., 1917.) 
 
 tCalllephlaltes graphollthas (Cres.), Phanerctoma tibial 's Hald., MIcrobracon sp. 
 
24 
 
 THE FALL WEBWORM. 
 
 (Hyphmitria cunea Drury.) 
 
 This insect is well known to all pecan growers. It forms the 
 familiar webs enclosing the tips of the branches. The adult moth 
 is about an inch across when the wings are spread. These moths 
 are usually pure white in color, although sometimes they are marked 
 with black spots on the wings. (Plate I, fig. 5.) The eggs are laid 
 in clusters of several hundred on the under side of the leaves. The 
 moth usually covers the egg batch with her body and wings, re- 
 maining in this position until she dies. (Plate VII, figs. 1 and 2.) 
 
 Upon hatching the young caterpillars commence feeding upon 
 the surface of the leaves and as they feed they enclose the foliage 
 in a web. When they exhaust the food within the web they en- 
 large it, including more and more leaves until the entire tip of 
 the branch is covered, forming the unsightly nest with its en- 
 closed brown and dead leaves which is such a familiar sight on 
 many kinds of trees. The caterpillars are usually yellow and are 
 clothed with long black and yellow hairs. Occasionally they are 
 very dark, almost black in color. 
 
 When fully grown the larvae leave the nests and crawl to some 
 secluded spot, under loose bark, under boards and sometimes just 
 below the surface of the soil. Here they pupate and later the moths 
 emerge to lay eggs for the next generation. 
 
 In southern Georgia there are two broods a year and a partial 
 third brood. That is, some of the late caterpillars of the second 
 brood do not mature the first season. The insect spends the win- 
 ter in the pupal stage, the moths emerging in the spring. The first 
 nests appear about the middle of May, the second brood nests ap- 
 pearing in August and September, and the partial third brood also 
 appearing late in September and into October. 
 
 Aside from the unsightly appearance which the nests give the 
 trees, this insect is not of serious importance during most years and 
 in most localities, though its feeding is bound to check the growth 
 of the trees to some extent. This is especially true in the case of 
 the young groves and nursery stock. Occasionally, however, the 
 damage is very serious, as in 1916, around Thomasville. During 
 that year the species was abundant throughout the summer and by 
 
25 
 
 tke middle of September several groves were almost defoliated. 
 (Plate VIII, fig. 1.) Most of these groves were young ones, but 
 one, composed of nine year old trees, was so severely attacked that 
 by the end of September somewhat over 40% of the foliage of the 
 entire grove had been eaten by the caterpillars. Of course this 
 work was not evenly distributed, so that while a very few trees 
 were not attacked, many were entirely defoliated. In addition 
 to eating the foliage the caterpillars fed on the shucks of the nuts. 
 As a result the shells were badly stained and it was practically im- 
 possible to remove the uneaten portion of the shucks from the nuts, 
 so that the crop on these trees was almost worthless. (Plate VIII, 
 fig. 2.) 
 
 CONTROL. 
 
 Such outbreaks are entirely unnecessary if care is taken to de- 
 stroy the caterpillars early in the season. This may be done by 
 systematically destroying the webs with the worms in them. They 
 can be burned with a torch, or cut off and burned later. Many peo- 
 ple simply twist the nests out of the branch by means of a stick with 
 a nail driven partly through one end, and then crush the larvae on 
 the ground. With a little care in this matter the grower will have 
 no trouble in controlling the pest. 
 
 WALNUT OR PECAN CATERPILLAR. 
 
 (Datana integerrima G. & R.) 
 
 This is another leaf-eating insect which feeds upon the pecan. 
 The larvae are dark with two white stripes on each side of the 
 body, and are clothed with a few short hairs. The adult moths are 
 yellow brown with four white stripes across each front wing. 
 
 The eggs are laid in masses of several hundred on the under side 
 of the leaves. (Plate VII, fig. 3.) The caterpillars feed on the 
 foliage. Unlike the Fall Webworm these insects do not spin webs 
 but move freely about the trees. When nearly grown the larvae all 
 gather together on the trunk of the tree on which they are feeding 
 and shed their skins for the last time. They then go back to the 
 branches and feed for a short period after which they leave the 
 tree and enter the ground to pupate. 
 
26 
 
 These insects may be easily killed while they are in the bunch 
 on the trunk of the tree. They can be scraped off and crushed. 
 This will greatly reduce the numbers of future generations. In 
 cases where the insect is very numerous the trees should be sprayed 
 with arsenate of lead, II/2 pounds of powder or 3 pounds of paste 
 to 50 gallons of water. 
 
 THE PECAN CATOCAItAS. 
 
 {Catocala spp.) 
 
 At least two species of Catocalas feed on pecan. The adults 
 are large moths, with greyish or dark brown front wings. The hind 
 wings of one species are yellow with two transverse black lines, 
 while those of the other are dark brown with a narrow band of 
 white. 
 
 The caterpillars, when full grown, are large, one measuring over 
 two inches in length and the other three inches. Both are dark grey 
 with various markings. The hide is tough and leathery in appear- 
 ance, and the caterpillars are sometimes known as "alligator 
 worms. ' ' 
 
 These insects, because of their coloring and their habit of hiding 
 in crevices in the bark during the day time, are seldom noticed. 
 Ordinarily they are not particularly injurious but they may be- 
 come so, occasionally. The larvae are usually present only in 
 April and May. They may be controlled by hand picking or by 
 an arsenical spray. They will also gather, at night, under bands of 
 burlap, if these be tied loosely about the trunks, and can be col- 
 lected and destroyed the following morning. 
 
 TWia GIBDLEES. 
 
 (Oncideres cingulata Say.) 
 
 The twig girdlers are probably the most widely known of all 
 the pecan pests and they occur throughout the pecan belt. There 
 are two species, but the only one observed thus far, injuring the 
 trees in this state, is cingulata. Both apparently work in the same 
 manner. 
 
27 
 
 The female beetles girdle the small branches of the trees and 
 lay their eggs in these. The cut branches eventually break and fall 
 to the ground. It is this pruning work which is known to the grow- 
 ers, the beetles themselves seldom being seen. As has been said this 
 girdling is done by the female, which lays its eggs in these cut twigs. 
 The work starts about the middle of September and continues un- 
 til December. The female, after girdling a twig, proceeds to lay 
 eggs in the cut-off portion, from one to several eggs being depos- 
 ited in a single twig. The beetle cuts a slit just below a bud, then 
 thrusts her ovipositor through this slit between the wood and the 
 bark and deposits a single long slender white egg. (Plate IX, fig. 
 2.) She usually scars the bark with transverse shallow grooves, be- 
 low the point where the egg is deposited. (Plate IX, fig. 1.) The 
 purpose of this scarring is not certainly known. It probably aids 
 in protecting the egg in some manner. There can be no doubt, on 
 the other hand, that the girdling of the twig is for the purpose of 
 killing it, since its continued growth would crush the eggs. Also, 
 the young are probably unable to feed on live wood. 
 
 The eggs hatch in a little less than a month and the white 
 borers immediately commence feeding. This feeding continues 
 through the winter and on till the next fall, the borers becoming full 
 size and pupating in late August or early September. In some, 
 cases it appears that the adults do not emerge the first year, but 
 the pupae, or perhaps the larvae live over till the next year. 
 
 Under ordinary circumstances the injury caused by these in- 
 sects is not of serious importance. When very abundant, however, 
 especially in young groves, the girdlers may cause very material 
 damage. 
 
 In order to control this species all the fallen twigs should be 
 gathered during the fall and winter and burned. It is not possible 
 to destroy the insects entirely as they also attack hickories and per- 
 simmons, in the woods, where it is practically impossible to em- 
 ploy this method. If followed faithfully, however, the grower 
 will have no difficulty in keeping the girdlers well in hand. 
 
 FLAT HEADED BORERS. 
 
 The flat headed borers are the most abundant and most de- 
 structive of the borers attacking the pecan. The adults of these 
 
28 
 
 borers are flat, hard beetles usually shiny and with metallic lustre. 
 The larvae are whitish grubs with broad flat heads, the body cyl- 
 indrical and much narrower than the head. Three species have 
 been taken from pecan,. thus far.* Of these the most important 
 seems to be the Apple Tree Flat Headed Borer. 
 
 The larvae bore into the bark and feed between the bark and 
 the wood. As is well known this is the part of the tree which is 
 alive and growing. So wherever these insects bore, that por- 
 tion of -the tree is killed. On small trees or where the number of 
 borers is large these tunnels may extend entirely around the tree, 
 thus girdling and killing it outright. 
 
 The adult beetles emerge principally during May and deposit 
 eggs in crevices in the bark. As soon as these eggs hatch the larvae 
 tunnel into the bark. When fully grown these larvae enclose them- 
 selves in cells composed of borings and frass and there pupate. The 
 following spring the adults emerge and lay eggs for the next gen- 
 eration. 
 
 Judging by evidence recently obtained there may either be two 
 broods a year or it may sometimes require two years for the in- 
 sects to mature. The fact that larvae of two sizes have been found 
 in the fall leads to one of these conclusions.! 
 
 The most satisfactory method of combating these insects so far 
 known, is to dig them out. Their presence is usually indicated by 
 cracks in the bark along a depressed or sunken area. The tunnels 
 should be opened and then painted with a good quality of white 
 lead paint to prevent further decay. 
 
 THE COSSID BOEER. 
 
 (Cossula magnifica Strecker.) 
 
 This is the insect whose larval stage and work are referred to by 
 growers as "round heads" and "round head work." These are not 
 round headed borers, however, the adult of the round head being 
 a hard-shelled beetle, with long antennae or "horns," much like the 
 adult of the twig-girdler, while the adult of the cossid borer is 
 a moth. (Plate I, fig. 3.) 
 
 *Chrysobothrls femorata Fab. (The Apple Tree Flat Headed Borer), C. scitula 
 and Agrillus anxious. 
 
 tGill states that this difference is due to the fact that the adults emerge at any 
 time from March to November, that is, that there is no definite period of a few 
 weeks when they appear and lay eggs. U. S. D. A. Farmer's Bulletin, 843, p. 39 
 (1917). 
 
29 
 
 This insect works within the wood of the tree, attacking the 
 trunk and the larger branches. It attacks trees which are appar- 
 ently sound in every way. In ordinary infestations the damage 
 done is not particularly serious, but the borers may eat out so much 
 of the wood, in a young tree, as to cause it to break in a high wind. 
 
 This species always leaves a hole through the bark at the be- 
 ginning of its burrow. (Plate IX, fig. 3.) Through this hole it 
 pushes out castings, rather large pellets of a yellowish, or fre- 
 quently reddish color. These are very noticeable, at the foot of an 
 infested tree, and through them attacks by this insect can always 
 be located. 
 
 The moths appear in the spring. The work of the larvae hatch- 
 ing from their eggs is not apparent until the next fall, when the 
 castings can be found under infested trees. The larvae feed till 
 spring, then, after enlarging the entrance hole to their burrow, 
 they pupate within it. When the moth emerges it leaves its empty 
 pupal skin protruding from the burrow. It seems certain, at least 
 in south Georgia, that there is one generation a year. 
 
 CONTROL. 
 
 This borer is easily controlled by injecting a little carbon bi- 
 sulphide into the burrow and then plugging it with wax or even 
 chewing gum. Some growers use a little medicine dropper for in- 
 jecting the liquid, but one man who has had good success in con- 
 trolling this insect uses a different method. He has his men carry 
 with them a little vial of bi-sulphide, a small wad of cotton lint 
 and a little ball of wax. This wax is made by melting together 
 equal parts of beeswax and tallow. When thoroughly melted this 
 is dropped into cold water and, as quickly as possible, is worked up 
 into balls as big through as a quarter. Whenever a man sees evi- 
 dences of borer work, he takes a bit of cotton, dips it into the bi- 
 sulphide and pushes it into the burrow, after which he plugs the 
 burrow with wax. 
 
 This method has been mentioned at some length because of the 
 fact that it shows the constant care and watchfulness exercised by 
 this grower. With both cossids and flat-heads the most important 
 point in control is watchfulness. Every time that evidences of their 
 
30 
 
 presence are seen steps should be taken, immediately, to eradicate 
 them. If this is done the grower will have little difficulty in con- 
 trolling these pests. 
 
 SHOT HOLE AND PIN HOLE BORERS. 
 
 This group, following the general classification as made by 
 growers, really includes several groups of insects which are quite 
 widely separated in their characters, habits, etc. For all practical 
 purposes, however, the grouping is perfectly sound. The presence 
 of all these insects is evidenced by the smooth round holes which 
 they leave in the bark of infested trees, these holes varying in size 
 as indicated by the name of the group. Moreover, all these insects 
 attack only such trees or portions of trees as are dead, dying or 
 considerably weakened by other causes. They seldom do any ac- 
 tual damage to a grove, being dangerous only through the fact 
 that they may attack and kill a tree, which though in weakened 
 condition might otherwise recover. 
 
 The principal shot hole borer is known as the Red Shouldered 
 Shot Hole Borer.* This insect caused considerable anxiety 
 throughout south Georgia during the spring of 1917. The adult 
 bores into a branch or even the trunk of a young tree, usually 
 through, or just above a leaf scar. It then forms a circular tun- 
 nel running partly, or entirely around the limb just within the 
 woody portion. In this tunnel it lays its eggs, the young burrow- 
 ing up the limb. (Plate IX, fig. 4.) These limbs are very easily 
 snapped off at the location of the circular tunnel. 
 
 As stated above, the work of this species was very abundant in 
 1917, and at the time of its discovery the trees appeared to be in 
 perfectly normal condition. Examination soon showed, however, 
 that the infested trees suffered, invariably, from winter injury of 
 so serious a nature that they must have died eventually from that 
 cause alone, though at the time they had every outward appear- 
 ance of perfect health. 
 
 Another species of general occurrence during the same spring 
 was the Pecan Ambrosia Beetle,t a little beetle which makes a hole 
 less than one-thirty-second of an inch in diameter. This insect at- 
 
 •Xylebiops (Sinoxylon) basilare Say. 
 tXyleborinus (Xyleborus) pecanis Hopk. 
 
31 
 
 tacks the trunk or branches, boring straight into them for a short 
 distance and then turning up or down and following the general 
 direction of the grain. It lays its eggs in a small chamber and the 
 young borers, upon hatching, feed together in the egg chamber. 
 This insect causes a greenish discoloration of the wood, especially 
 about the egg chamber where the young larvae feed. As was the 
 case with the shot hole borer, mentioned previously, the trees ap- 
 peared to be perfectly sound, except for the work of these borers. 
 Further examination, however, showed that they, too, were suf- 
 fering from winter injury. 
 
 While an attack by any of the various species forming this group 
 is a certain sign that the host is in an unhealthy condition, such 
 trees or portions of trees should always be removed and burned, 
 for the general good of the grove. In addition to this all cut sur- 
 faces, of any size, should be treated with a mixture of coal tar and 
 creosote to prevent decay which will attract these beetles. This 
 should be borne in mind particularly when top working trees. 
 
 THE LESSER PECAN TREE BORER. 
 
 (Synanthedon (Sesia) geliformis Walker.) 
 
 Two different species of clear winged moths, both related to 
 each other and to the peach tree borers, occur on pecan. One 
 species has been recorded by Ilerrick* as attacking the pecan in 
 Mississippi and this species appears to be the one attacking it in 
 North Carolina. The moth is deep steel blue in color with yellow 
 bands on abdomen and legs. Gossardf found a species attacking 
 pecan in Florida and, not finding the adult, judged it to be the 
 same insect. We have never taken this insect in Georgia, our form 
 producing a moth which is dark brown in color, with a bright red 
 hind body, or abdomen. It also seems probable that this is the 
 species occurring in Florida. Since this form is related more 
 closely to the Lesser Peach-tree Borer, and since moreover, the 
 name Pecan Tree-borer has already been applied to the other spe- 
 cies, it has seemed best to call our insect the Lesser Pecan-tree 
 Borer. 
 
 *(Sesla scitula Harris), Herrick, Glenn W., Miss. Agr. Exp. Sta., Bull. 86 (1804), 
 p. 11. 
 
 tGossard, H. A., Fla. Agr. Exp. Sta., Bull. 79 (1905), p. 299. 
 
32 
 
 The life history of this species has not yet been thoroughly 
 worked out. Moths appear over a period of at least three months 
 in the spring, from the first of March to the last of May. They lay 
 their eggs on the bark, and the young larvae, upon hatching, bur- 
 row inward and commence feeding in the inner layer of bark. 
 (Plate X, fig. 1.) The insects attack trees of all sizes and may be 
 found anywhere from a foot above ground to 15 or 20 ft. above, 
 in the branches. They spend the winter in the larval, or borer 
 stage, pupating during the late winter or early spring. On 
 emerging the moth leaves its empty pupal case protruding some- 
 what, usually from beneath a scale of the bark. We have not been 
 able to determine whether there are two generations a year or not. 
 Since the lesser pecan-tree borers eat out only a small area, 
 especially when compared to the size of the trees, they usually 
 do not cause any material injury. Owing to the fact, however, 
 that they appear to congregate mainly in a few trees they may some- 
 times become so numerous as not only to seriously injure a tree but 
 to girdle it, thus killing it outright. (Plate X, fig. 2.) 
 
 CONTROL. 
 
 No particular method of control can be recommended. The 
 borers are worse on trees with rough scaly bark than on those whose 
 bark is smooth. An occasional examination, through the winter, by 
 removing rough pieces of bark, will usually reveal the work of these 
 insects, if they are present, and the larva can be located and killed. 
 
 Kepellant white washes have been tried to some extent but noth- 
 ing of this nature has proven satisfactory thus far. 
 
 A PECAN NUT CUECULIO.* 
 
 Proliably the Walnut Curculio. 
 
 (Conotrachelus juglandis Lee.) 
 
 For several years reports reached this office of a weevil work- 
 ing in pecan nuts and occasionally specimens of nuts with the 
 characteristic weevil holes in them were sent in. These came from 
 Putney, Ga., Thomasville and one or two places in north Georgia. 
 
 *By C. S. Spooner. 
 
PLATE VIII. 
 
 Fig. 1. Young tree, four years old, defoliated by web-worms. 
 
 Pig. 2. 
 
 Nearly mature nuts attacked 
 by web-worms. 
 
PLATE IX. 
 
 Fig. 
 
 1. Twig girdler; egg punc- 
 ture and scarring. 
 
 Fig. 2. Twig girdler; egg. 
 (Bark has been removed.) 
 
 Fig. 8. Cossid Borer. Entrance 
 to burrow. (Much reduced.) 
 
 Pig. 4. Red shouldered Shot-Hole 
 Borer. Entrance hole of adult, 
 above bud, and channel made by 
 young. 
 
PLATE X, 
 
 Fig. 1. Lesser Pecan Tree Borer and work on tree 
 (almost natural size). 
 
 Fig. 2. 
 
 Nine year old tree practically dead from work 
 of Lesser Pecan Tree Borer. 
 
PLATE XL 
 
 Pecan Phylloxera Galls on leaves. 
 
33 
 
 Not until 1915, however, were these insects observed in any num- 
 bers. 
 
 In the spring of 1915 attention was called to a Hican tree at 
 DeWitt, Ga., well loaded with nuts w-hich were attacked by a cur- 
 culio. They showed the characteristic egg puncture with the cres- 
 cent shaped slit below. Fully 90 ^/c of the nuts of this tree were 
 attacked and fell. At the same time in other localities the same 
 insect was observed working in the tender new shoots of pecan trees. 
 In these cases the larvae were tunneling out the center of the shoot 
 and caused its death. The probable reason for this difference in 
 habit is that the Hican nuts are much earlier and larger than the 
 pecans. They were large enough to support the young weevil larvae 
 while the pecan nuts were not. Therefore on the pecans the in- 
 sects had to deposit their eggs in the new sprouts. 
 
 The full life history of this insect has not been worked out. Ac- 
 cording to Mr. W. D. Pierce, of the U. S. Bureau of Entomology, an 
 authority on this group, the insect probably has three broods a 
 year in Georgia. Thus this insect can become a serious menace 
 to the pecan industry. 
 
 The larva of this insect when attacking the nuts eats out the 
 inner part of the nut which soon falls to the ground. The grub then 
 bores its way out and enters the ground where it forms a cell in the 
 earth and pupates. 
 
 Control measures have not been worked out yet, but shallow 
 plowing at the time the weevils are in the ground in the pupal 
 state is indicated. 
 
 THE HICKORY AND PECAN WEEVIL. 
 
 (Balaninus caryae Horn.) 
 
 This insect has been reported as destructive to pecans, in Geor- 
 gia, only during single widely separated seasons and from very lim- 
 ited areas. As it might become of serious importance, however, it is 
 well for the grower to know about it and to watch for it. 
 
 The adult is a dark brown weevil, having a very long, slender 
 snout. The young is a white grub, like that found in chestnuts. 
 In fact this insect is very closely related to the chestnut weevil. 
 The adult lays her egg in the nut, the grub hatching out and feed- 
 
34 
 
 ing in the nut until fall, when it bores a round hole out through the 
 shell, goes into the ground and pupates. The adults emerge during 
 the spring or early summer. As will be seen, it is practically im- 
 possible to tell whether an unopened nut has been attacked or not, 
 unless the grub has left it. The egg puncture is so small that one 
 can hardly find it. 
 
 CONTROL. 
 
 Probably the best method for controlling this pest is to fumi- 
 gate the nuts with carbon bi-sulphide, using about 10 pounds to 
 1,000 cubic feet. It is also reported that the grub may be killed 
 by heating the nuts to 125^-150° Fahrenheit. With either method 
 it is necessary to gather and treat all the nuts from trees which 
 are found to be infested. They must also be gathered early, be- 
 fore the grubs have entered the ground. 
 
 One severe outbreak near Thomasville, Ga., was apparently 
 controlled by turning hogs into the grove as early as possible in 
 the fall. At least, no other control methods were tried and the in- 
 sects did not cause any injury in the grove the following year. 
 
 A LEAT FEEDING BEETLE.* 
 (Diplotaxis excavata Leconte.) 
 
 On April 16th, 1912, at DeWitt, Ga., a large number of leaves 
 and young growing tips of pecans were found on the ground. These 
 had been cut off by insects. For some time the cause of this trou- 
 ble could not be located, but finally numbers of small holes were 
 noticed in the ground. On examination these were found to con- 
 tain a species of beetle known as Diplotaxis excavata. They are 
 cylindrical black beetles a little less than half an inch long. They 
 resemble somewhat the well known May bettles. The larvae live 
 under ground on the roots of various plants and only the adult 
 attacks the pecan. The injury was quite severe and had a decided 
 pruning effect on the trees. The attack lasted about two weeks, 
 when the beetles disappeared. 
 
 If the beetles occur in sufficient numbers to seriously affect the 
 
 *By C. S. Spooner. 
 
35 
 
 trees they can be controlled by spraying at their first appearance 
 with arsenate of lead at the rate of 3 pounds of paste, or 11/2 pounds 
 of powder, to 50 gallons of water.* 
 
 LEAF HOPPER, t 
 
 (Empoasca sp.) 
 
 Occasionally one notices that the leaves of pecans, especially 
 the new tender ones, are very much curled and distorted. This is 
 caused by small green sucking insects known as leaf-hoppers. They 
 are very much like the apple leaf-hopper, bright green in color 
 and about one-fourth of an inch in length. 
 
 These insects feed on the under side of the leaf. They have 
 mouth parts fitted for sucking and pierce the surface of the leaf 
 with their beaks, sucking the juices of the plants. This causes the 
 leaves to curl and when the insects are numerous seriously af- 
 fects the nutrition of the tree, especially young trees with few 
 leaves. 
 
 These insects can be readily controlled by a spray of whale 
 oil soap, one pound to two gallons of water. As this insecticide 
 kills by contact and not by being eaten care must be taken to 
 hit the under side of the leaves where the insects stay. 
 
 PECAN PHYLLOXERA. 
 
 (Phylloxera sp.) 
 
 The pecan phylloxera is a small plant louse which causes the 
 formation of galls on the leaves and leaf stems. (Plate XI, fig. 1.) 
 It is seldom found on old trees, but occurs quite frequently on young 
 ones and is very common on nursery stock. It apparently does no 
 damage in particular and up to the present no measures of control 
 have been needed against it. 
 
 *At least one species of the true May beetle may cause serious Injury of a 
 somewhat similar nature. Such an attack was observed near Augusta, In 1917, the 
 trees being almost entirely defoliated. (W. F. T.) 
 
 tBy C. S. Spooner. 
 
36 
 
 THE PEQAN APHIS. 
 
 (Monellia costalis F.) 
 
 This is the small yellow species with the front margins of the 
 fore wings bordered with dark brown or black, which occurs on 
 pecans throughout south Georgia. It is accompanied by a second, 
 somewhat smaller species* of much less common occurrence which 
 lacks the broad, dark wing margin. This second species carries its 
 wings over itself like a roof while the commoner species holds them 
 flat over its back. 
 
 The aphids may first be found, in the spring, about the last of 
 March, at Thomasville. When full grown these insects are winged 
 and only females occur. From then on, throughout the summer 
 and early fall, generation follows generation, all adults being fe- 
 males and bearing living young (parthenogenetic and viviparous). 
 Also they are all winged. There may be as many as twenty-one 
 such generations during a season, each female producing about thir- 
 ty to forty young on the average. We have a record of one which 
 bore 239 young. 
 
 About the middle of October young aphids are found which dif- 
 fer somewhat in color and markings and in general appearance 
 from the others. These eventually grow into egg laying (oviparous) 
 females and males.. These females are without wings (apterous) 
 even when fully grown. The males are winged but are somewhat 
 smaller than the summer form and bear black markings on the 
 thorax, by which they may easily be determined. 
 
 These males and females mate and the latter lay small eggs, de- 
 positing them on the trunk and main branches, under loose bark. 
 This egg stage carries the insects over winter, the eggs hatching 
 the following March to start another year's cycle. 
 
 Both species feed on the under surface of the leaves, appar- 
 ently preferring rather old foliage to the newer and more tender 
 growth. The insects with flat wings, and their young, are found 
 well scattered about over the leaves, while adults of the other spe- 
 cies are usually to be found surrounded by several young, all rather 
 close together. This seems to be due to the fact that the flat winged 
 species is more "nervous" than the other, not remaining in one 
 'Monellia sp. ' 
 
37 
 
 place as long and being much more prone to jump when disturbed 
 in any way. 
 
 These species do not appear to cause any serious damage, at 
 present. For one thing, although they reproduce so rapidly, quan- 
 tities of them are destroyed by lady beetles and their young, which 
 swarm over the infested trees. In case of a severe outbreak the 
 trees should be sprayed with a nicotine solution and soap. 
 
 SPITTLE INSECT. 
 
 During 1917 this insect, whose young live within small accumu- 
 lations of a froth-like material, was very abundant on pecans in 
 some localities, especially about Thomasville and Valdosta, and was 
 the cause of many inquiries from growers in these districts. 
 
 , In the spring the young feed mainly on the swollen bases of the 
 leaf stems. Later they attack the young nuts and it is on these 
 that they are usually to be found during the summer and early 
 fall. It is this habit which caused anxiety among the nut growers. 
 Numerous observations and experiments have failed, thus far, to 
 show any particular evidence of injury by this species. In our ex- 
 periments, nuts fed on by the insects were no more liable to fall than 
 were those which were free from attack. Consequently, the pres- 
 ence of this species need not cause any uneasiness and no control 
 measures are needed. 
 
38 
 PECAN SCAB. 
 
 {Fusicladium effusum.) 
 
 BY C. S. SPOONEE. 
 
 Pecan scab is the most serious disease affecting the pecan. It 
 is caused by a fungus which enters the tissues of the leaves and nuts 
 and seriously affects their development. Its presence may be recog- 
 nized by small black pustules on the surface of both leaves and 
 nuts. The pustules are about 1-18 of an inch in diameter and may 
 be so numerous as to practically cover the entire surface. The pus- 
 tules contain the spores of the fungus and it is by means of these 
 spores that the disease is spread. They escape from the pustules 
 and lodge upon fresh surfaces where, in the presence of moisture 
 they germinate, enter the tissue and develop into the fungus which 
 in turn develops new pustules and spores. 
 
 "When the disease is confined to the leaves it does not seriously 
 affect the health of the tree, but when it attacks the nuts it does 
 affect the development of the nut. It causes the nut to drop off 
 or reduces its size according to the abundance of the fungus. 
 
 Susceptible and Immune Varieties. 
 
 There is a great difference in the susceptibility of the different 
 varieties of pecans to scab. Some are apparently entirely im- 
 mune, others are attacked very slightly, showing scab spots on a 
 few nuts which are growing close to the trunk or heavily shaded by 
 the branches, while others are very severely attacked so that few if 
 any nuts escape injury. This is strikingly shown by trees of dif- 
 ferent varieties growing next one another. On one the whole crop 
 will be diseased, while on the other no trace of the disease will be 
 found. There is also apparently a sectional difference in the de-. 
 gree of susceptibility to scab. For example, in the Thomasville dis- 
 trict the Delmas scabs badly ; while in the Albany district it is quite 
 free from disease. In Florida the Van Deman is reported as scab- 
 bing badly, while with us it is only slightly affected. 
 
 The varieties which are most subject to scab with us are, Geor- 
 gia, San Saba and other Texas varieties, Capitol, Delmas and many 
 seedlings. Seedlings are usually very severely injured by scab. 
 
39 
 
 Van Deman, Schley, Alley, Halkert, Mobile scab to a slight de- 
 gree, but not enough to warrant uneasiness. Scab has also been re- 
 corded as occurring on Stuart and Jewett to a slight extent. 
 
 Present indications show that Money-maker, Russell, Stuart, 
 Schley and Alley are among the better known varieties which are 
 safe to plant from the standpoint of scab. 
 
 Seasonal Difference. 
 
 There is a great seasonal difference in the severity of scab. Very 
 wet seasons promote the growth of the fungus to a great degree. 
 One season has been observed by the writer in which practically 
 every Georgia nut in one grove was destroyed by scab before the 
 season was half over. 
 
 On the other hand in very dry seasons the loss is hardly notice- 
 able, when the nuts are so lightly attacked that the greatest injury 
 is shown by the presence of many under-sized nuts. Between these 
 two extremes the amount of damage will vary according to the 
 season. 
 
 Bemedial Measures. 
 The aim in spraying for Fungus Diseases. 
 
 In discussing control measures, the underlying principle of 
 spraying for fungus diseases of plants should be remembered. The 
 fungus is spread through the air by means of very minute spores. 
 These lodge on leaves and nuts and there remain dormant until they 
 come in contact with moisture. Thus after a rain, when the leaves 
 are still wet the spores germinate and send a small thread into the 
 tissue of the plant. The fungus then develops rapidly. 
 
 The object of the spraying is to have the poison on the leaves 
 when the moisture comes so that the presence of the poison in the 
 water will kill the spore before it has time to germinate. There- 
 fore a spray applied before a rain is infinitely more effective than 
 one applied afterwards. 
 
 The Choice of a Fungicide. 
 
 A fungicide is a chemical combination applied to a plant for 
 the purpose of controlling or destroying fungi which attack the 
 
40 
 
 plant. There are several fungicides which give excellent results 
 in combating other fungus diseases and several of these were tried 
 on pecans to determine which was the most effective against the 
 scab. 
 
 Atomic sulphur was applied on one block of trees at the rate of 
 seven pounds to fifty gallons of water and to another block at the 
 rate of five pounds to fifty gallons of water. No beneficial results 
 whatever were observed. 
 
 Lime sulphur (Commercial) was used at the strength of one gal- 
 lon to thirty gallons of water and one gallon to fifty gallons of 
 water. Both of these strengths burned the foliage quite severely 
 and did not control the disease. Some slight benefit was noticed, 
 but because of the severe burning this fungicide was abandoned. 
 
 A winter spray of lime sulphur at the strength of one gallon 
 to ten of water, was applied January 22nd. No benefit was seen 
 from this treatment. The trees which had received this treatment 
 together with some which had not received it were later sprayed 
 with Bordeaux Mixture. No difference in the results was ob- 
 tained on the two blocks. 
 
 Bordeaux Mixture was used at strengths of 3-3-50 and 5-5-50. 
 The results with the two strengths did not differ so that the 3-3-50 
 formula was used. This fungicide was used in many experiments. 
 A differing number of sprays was applied and in many cases good 
 results were obtained. Following is a summary of the experiments : 
 
 In 1912 Bordeaux was used on only one tree. Most of the work 
 of this year was confined to atomic sulphur and lime sulphur. As 
 shown above, these two fungicides were unsatisfactory and were 
 abandoned. The one tree sprayed with Bordeaux gave some evi- 
 dence in favor of this fungicide and it was tried extensively in 
 1913-1914. 
 
 The experiments in 1913 were carried out with Bordeaux Mix- 
 ture at the strength of 3-3-50. The trees were divided into five 
 blocks and treated as follows: Block C was left unsprayed as a 
 check on the other blocks. Block A was sprayed April 18th and 
 June 3rd. Plot D sprayed March 17th, April 18th and July 16th. 
 Plot E sprayed March 17th, April 18th, June 3rd and July 16th. 
 Plot F sprayed April 18th, June 3rd, July 16th. 
 
 In getting the following percentage the drops which showed 
 
PLATE XII. 
 
 WMM 
 
 ■| 
 
 
 
 ■[ 
 
 ■ 
 
 Hi 
 
 ^H 
 
 H 
 
 
 ^vJ^^H 
 
 1 
 
 i 
 
 9 
 
 ^^p 
 
 Hi 
 
 ^F 
 
 
 H 
 
 1 
 
 Ih 
 
 ^^^^^^^Ki -."'' 
 
 ""^-\r~ 
 
 N 
 
 ^^'— -^^As^^B 
 
 ^1 
 
 w 
 
 
 ^v' 
 
 
 ^°^ 
 
 
 ^K 
 
 
 '^^: 
 
 ^^^^^^^^^Hr< 
 
 
 ^sS&^ 
 
 
 ^^^^^^^K^ 
 
 
 V^BgK 
 
 1 
 
 ^/ 
 
 4-- 
 
 ji^^^^H 
 
 1 
 
 i 
 
 J 
 
 o 
 o 
 
 2c 
 
 ci3 
 <BrH 
 
 >> 
 
 ^ bii 
 f/fe 
 
 « 
 
 60 
 
 s 
 
 bo 
 C to 
 
 roc 
 
 r? CO 
 0*i 
 
PLATE XIII. 
 
 Fig. 1. Diseased kernels, showing appearance of Kernel Spot. 
 
 Pig. 2. Brown Leaf Spot. Moderately severe infestation. 
 
PLATE XIV. 
 
 Pecan scab (Fusicladium effusum). 
 
PLATE XV. 
 
 Spraying pecan trees with gasoline sprayer (using tower). 
 
41 
 
 scab supposedly would have matured if it had net been for the 
 scab, so that these together with the matured nuts were taken as the 
 normal crop. A careful count was kept of all drops and those 
 showing scab were counted separately. The number of the drops 
 showing scab divided by the total crop would give the percentage 
 of the crop affected by scab. 
 
 In Plot C, unsprayed, 72% of the crop dropped be- 
 cause of the scab. 
 
 Plot A, two sprayings April 18th and June 3rd, lost 
 15% of the crop. 
 
 Plot D, sprayed March 17th, April 18th, July 16th, 
 lost 29% of the crop. 
 
 Plot E, sprayed March 17th, April 18th, June 3rd, 
 July 16th, lost 20% of the crop. 
 Plot F, sprayed April 18th, June 3rd, July 16th, 
 lost 24% of the crop. 
 
 It will be seen that all of the sprayed plots showed a distinct 
 improvement over the unsprayed. The plots varied somewhat in un- 
 expected ways, as is shown by Plot A having a better percentage 
 than Plot E, although the latter had two more sprayings. I'his was 
 caused partly by the variations in the size of the crop on different 
 trees and other factors which could not be controlled. It also shows 
 that the two sprays, applied April 18th and June 3rd, were the 
 most essential ones in the control of the scab. There can be no 
 question but what it paid to spray these trees. 
 
 The year 1914 was very dry and while extensive spraying experi- 
 ments were carried on the results are very hard, if not impossible, 
 to tabulate. The scab showed up very late in the season, July 11th 
 being the date when it was first observed and then very little of it 
 was found. For this reason the damage to nuts, sprayed or un- 
 sprayed, was very slight. No difference could be found in the 
 niunber of drops caused by scab because there were so few of them 
 either on the sprayed or unsprayed trees. 
 
 A very decided difference could be observed while the nuts 
 were on the trees, however. On the sprayed trees the nuts showed 
 much less scab than those on the unsprayed trees and they ran 
 larger and better. While these experiments did not materially im- 
 pi'ove the crop they showed again that Bordeaux would control the 
 scab to a great extent. They showed no material benefit because 
 
42 
 
 tJhe season was so dry that spraying for this disease was not nec- 
 essary. 
 
 It will be seen from the above experiments that while no com- 
 plete control was effected, a very considerable amount of good was 
 accomplished by the spraying, especially in 1913, which was a fairly 
 wet season. An increased number of sprayings in wet seasons 
 would unquestionably give greater control. 
 
 No set rule can be given as to the dates of spraying. Each sea- 
 son will be different. The grower must be governed by the amount 
 of rainfall each year. It is well to apply a coat of the spray soon 
 after the nuts are formed. Subsequent sprayings can then be de- 
 termined later. The trees need not be sprayed during a long, dry 
 spell, but in wet weather spray every ten days or two weeks. 
 
 Too much emphasis cannot be laid on the necessity for thorough 
 spraying. A careless, hit or miss application costs as much to apply 
 and uses as much material as a good, thorough job and the results 
 are widely different. In many cases where statements are made to 
 the effect that spraying did not control the disease it can be shown 
 that the spraying was not carefully done. 
 
 Be sure to hit every leaf. If necessary it will be worth the 
 time of a reliable man to go with the spraying outfit to see that the 
 spray is properly applied. 
 
 Preparation of Bordeaux Mixture. 
 
 Bordeaux Mixture must be properly made to be effective. It 
 will therefore be Avell to give instructions for those who are unfa- 
 miliar with this Mixture. Bordeaux Mixture is made from copper 
 sulphate, lime and water. The formula 3-3-50 means that three 
 pounds of copper sulphate and three pounds of lime are used to fifty 
 gallons of water. Each ingredient should be mixed separately with 
 a little water and then each is poured in a separate barrel and 
 enough more water added to make twenty-five gallons of each solu- 
 tion. These are then poured together into the spray tank. Barrels 
 placed on a platform and connected up as shown in the figure make a 
 most convenient outfit for mixing Bordeaux. 
 
 The lime should be unslacked. If old air slacked lime is used 
 the resulting mixture is liable to seriously burn the foliage. Hy- 
 
43 
 
 drated lime, if readily obtainable, is the most convenient to use as 
 it is more easily suspended in the water. 
 
 If much of the solution is to be used it will be found best to tie 
 the required amount of copper sulphate in a sack and suspend the 
 sack near the top of a barrel of water. This should be done the 
 evening before spraying. It will have all dissolved by morn- 
 ing. The required amount can then be dipped out as needed. 
 
 Top Working to Immune Varieties. 
 
 The- question is often asked if it would not be best to top work 
 scabbing varieties with, immune varieties. In young groves this is 
 undoubtedly the best thing to do. Of course, it is not policy to 
 plant scabbing varieties in groves. However, in large, bearing 
 groves each grower must decide for himself, whether he 
 would prefer to spray or to top work his trees with the resulting 
 curtailment of his crop for several years. As to the expense con- 
 cerned, it is a question which is better. Over a long term of years, 
 the top-working, if successfully done, would be the cheaper. . 
 
44 
 PECAN DISEASES OTHER THAN SCAB. 
 
 BY C. G. CRITTENDEN.* 
 PECAN ROSETTE. 
 
 IMPORTANCE AND SYMPTOMS. 
 
 Pecan rosette is considered by growers of pecans, to be one of 
 the most serious diseases with which they have to contend. It 
 makes its first appearance in a tree through the putting out of 
 mottled yellow leaves which are usually more or less wrinkled and 
 undersized. It may appear over the whole tree at once, but often 
 affects one branch long before it shows up in the rest of the tree. 
 The affected branches are stunted and fail to grow the usual length. 
 This shortens the distance between the leaves and thus forms a "ro- 
 sette." A tree lightly affected one season may not show the dis- 
 ease the next season. However, trees badly affected seldom re- 
 cover. If a tree is badly affected the branches usually die back from 
 the tips, either the first season or later. In some cases, this dying 
 back may go so far as to kill the tree. More often, however, it 
 does -not go that far. In the spring new branches come out at the 
 base of the dead branch, and these in turn die back, so that the 
 final result in the case of a tree badly rosetted for years, is a 
 gnarled unsightly dwarf. (Plate XII, figs. 1 and 2.) 
 
 NATURE OF THE DISEASE. 
 
 Rosette is neither a fungus nor a bacterial disease, but is what 
 is termed a physiological disease and is, probably, the result of 
 some defect in nutrition. Orton and Randt have shown that it is 
 due to some unfavorable condition of the soil. "When they trans- 
 planted trees into holes from which rosetted trees had been re- 
 moved, a large proportion of these healthy trees became rosetted 
 and if the transplant was reversed and rosetted trees were planted 
 in places from which healthy ones had been removed, a large propor- 
 tion of these diseased trees recovered. These investigators also 
 found that budding or grafting healthy buds or scions on rosetted 
 stocks gave rosette in the scion and conversely that working buds 
 or scions from rosetted trees onto healthy stocks produced healthy 
 trees. 
 
 'Formerly pathologist with the Georgia State Board of EntomologJ^ 
 tOrton, W. A., and Rand, F. V. Pecan Rosette. Jour. Agr. Res. vol. 3, No. 
 2: pp. 149-174, 1914. 
 
45 
 
 The disease is non-parasitic and noninfectious and is the result 
 of some unfavorable condition in the soil. 
 
 CONTROL. 
 
 No method for curing rosetted trees can be recommended. 
 Trees which are badly diseased should be removed and replaced by 
 healthy trees. Many of these healthy trees are likely to become 
 rosetted, but some can be depended upon to remain healthy, others 
 will not be as badly affected as those removed, while some, prob- 
 ably, will be as bad as the old trees. 
 
 All rosetted nursery stock should be discarded and only thor- 
 oughly sound stocks used for budding or grafting. 
 
 In selecting a location for a grove, choose a good fertile soil 
 with a clay subsoil. Avoid a sandy subsoil and do not plant a 
 pecan tree where no other crcp -,vill succeed. 
 
 BEOWN LEAP SPOT. 
 
 {Cercospora fusca Rand.) 
 
 The brown leaf spot is the most prevalent and most conspicuous 
 leaf disease of the pecan. It probably occurs wherever the pecan is 
 grown. The loss occasioned by the disease is difficult to estimate, 
 as only the leaves are affected. In severe cases there may be con- 
 siderable defoliation of the trees. 
 
 Different varieties of pecan show little or no difference in sus- 
 ceptibility to the disease. 
 
 SYMPTOMS. 
 
 The disease first makes its appearance on a leaf as a small dark 
 brown irregular spot with an indefinite outline, which extends 
 through the leaf and is visible on both surfaces. There may be 
 many of these on one leaf. The spot increases in size and often 
 reaches a half inch in diameter, and the larger ones sometimes become 
 light broAvn in the center. (Plate XIII, fig. 2.) 
 
 CAUSE OF THE DISEASE. 
 
 Brown leaf spot is caused by a fungus, the threads of which 
 penetrate the leaf. When the spots are from five to six weeks 
 
46 
 
 old, club-shaped spores of the fungus are produced, usually on their 
 upper surface. These spores may be carried by wind to other 
 leaves where they produce new spots. First infections appear in 
 early summer and the disease continues to spread throughout the 
 summer and till fall. 
 
 CONTROL. 
 
 The disease is usually not severe enough to make it profita- 
 ble to attempt to control it. It may be prevented by thoroughly 
 spraying the trees three times with Bordeaux mixture. The first 
 spray should be applied soon after the trees are fully leaved out. 
 The second and third should follow at intervals of three to four 
 weeks. 
 
 KERNEL SPOT. 
 
 (Coniothyrium earyogeniim Eand.) 
 
 Up to the present time this disease has been given little consid- 
 eration, either by pecan growers or by workers on pecan diseases. 
 The loss occasioned by the disease has hitherto been small, only 
 occasionally on a single tree or in small groves here and there has it 
 been reported serious. However, the disease appears to be spread- 
 ing and the damage increasing. During the season of 1916, se- 
 rious loss was inflicted on some growers in the vicinity of Thomas- 
 ville and Cairo. One Thomasville grower sold his crop of Schleys, 
 which were damaged by kernel spot, for 25 cents per pound when 
 prices for good Schleys ranged from 50 to 60 cents. 
 
 SYMPTOMS. 
 
 As the name implies, the disease affects only the kernel'. It can 
 be detected only after the shell is removed. The spot on the ker- 
 nel is irregular in outline, dark brown or black and usually some- 
 what sunken. It is about 14 to % inch in diameter. (Plate XIII, 
 fig. 1.) 
 
 When the kernel is cut the brown diseased area is found to ex- 
 tend into the meat to a depth of perhaps % of an inch. The dis- 
 eased spot is bitter and imparts a bitter flavor to the rest of the 
 meat. 
 
CAUSE OF THE DISEASE,* 
 
 Kernel spot is caused by a fungus. This has been proven by 
 Rand, of the U. S. Department of Agriculture. The life history of 
 the fungus is not very well known. As far as is at present known 
 it affects only the kernel. When an affected kernel is placed un- 
 der moist conditions pycnidia or spore bearing bodies are formed 
 by the fungus. Inside the pycnidia are produced the spores which 
 are the means of reproducing the disease. At what time or just 
 how infection of the kernel takes place is not known. 
 
 CONTROL OF THE DISEASE. 
 
 No efforts have thus far been made to control the disease and 
 no specific method can be given at this time. However, there are 
 certain measures which can be recommended as giving promise. - As 
 previously stated, so far as is known, the disease affects only the 
 kernel of the nut. If this is true then removal from the orchard or 
 destruction of all nuts in the fall should reduce the amount of dis- 
 ease the following year. 
 
 Some varieties seem to be more susceptible to the disease than 
 others. The Schley appears to be most seriously affected and Suc- 
 cess and Curtis are probably more susceptible than others. 
 
 OTHER DISEASES OF PECAN. 
 
 NURSERY BLIGHT. 
 
 (Phyllosticta caryae Peck.) 
 
 This is a fungus disease which is confined almost entirely to the 
 nursery, where it often does considerable damage. Only the leaves 
 are aft'ected. ' ' Generally the first indications of infection appear 
 in the form of minute roundish spots which are dark reddish brown 
 on the upper surface and blackish on the lower. These slowly in- 
 crease in size until a diameter of 2 to 5 mm. (^-^2 ^^■) is often 
 reached in the individual spots. "With increase in size the center 
 of the spot on the upper surface assumes an ashen gray color, 
 
 *Investigations conducted during the season of 1917 seem to indicate that the 
 Green Soldier Bug (Nezara hilaris) is a very important factor in the production 
 of this disease. We have not been able to determine, absolutely, whether the spot 
 is caused by a fungus which is carried by the bug, or whether the spot is directly 
 due to the feeding of the bug. This bug is the insect frequently called a "pump- 
 kin bug" which occurs very commonly on cow peas. (William P. Turner.) 
 
48 
 
 which is usually bordered with reddish brown, while the lower sur- 
 face remains black throughout or with an occasional tiny ashen- 
 gray spot in the center of this dark colored area."* 
 
 CONTROL. 
 
 Spray with Bordeaux mixture four times. Begin spraying as 
 
 soon as the trees are fully leaved out and repeat at intervals of 
 
 three to four weeks. 
 
 ANTHRACNOSE, 
 
 {Glomerella cingulata (stonem) S. V. & S.) 
 
 This disease affects both the leaves and the nuts. The af- 
 fected spots on the leaves are irregular in outline and grayish brown. 
 They vary in size and sometimes cover a whole leaf. Leaves badly 
 affected usually fall to the ground. On the nuts the disease pro- 
 duces black sunken spots which are irregular in outline and 
 sometimes causes a heavy drop of half grown nuts. The dis- 
 ease is caused by a fungus. No method of control can be given at 
 the present time. 
 
 CROWN GALL. 
 
 {Bacterium tumefaciens (S. M. & Town.) 
 
 This disease is rare on the pecan. "When present it produces 
 swellings or galls ®n the tree trunk below the surface of the 
 ground. It is produced by the same bacteria which causes crown 
 gall of the peach, apple, etc. 
 
 » 
 
 CONTROL. 
 
 All nursery trees found to be affected with crown gall should 
 be discarded and destroyed. 
 
 MILDEW. 
 
 (Microsphaera alni (Wallr) Wint.) 
 
 Mildew is more or less common on the leaves and nuts of the 
 pecan, occurring most often on the lower shaded branches of the 
 tree. .It produces a white poAvdery covering often involving the 
 whole surface of a nut. The mildew produces little or no damage 
 and can be ignored. 
 
 ♦Rand, F. V. Some diseases of pecans. Jour. Agr. Res. 11, No. 4: pp. 303-S37, 
 
 T914. 
 
LIST OF AVAILABLE PUBLICATIONS, 
 GEORGIA STATE BOARD OF ENTOMOLOGY. 
 
 Bulletin No. 12— The Mexican Cotton Boll Weevil, 1904. 
 
 Bulletin No. 13 — Some Common Insects Injurious to the Apple, 1904. 
 
 Bulletin No. 26— Peach Leaf Curl, Yellows, Eosette and Little Peach, 1908. 
 
 Bulletin No. 34 — Wilt Disease of Cotton in Georgia and Its Control, 1911. 
 
 Bulletin No. 37 — Crop Pest Law of Georgia, Other States and Canada, 1912. 
 
 Bulletin No. 39— The Mexican Cotton Boll Weevil, 1914. 
 
 Bulletin No. 40— Cotton Wilt in Georgia, 1915. 
 
 Bulletin No. 41 — Some of the More Important Truck Crop Pests in Georgia, 
 
 1915. 
 Bulletin No. 42 — Annual Report of the State Entomologist for 1914. 
 Bulletin No. 43— The Principal Parasites of the Peach, 1916. 
 Bulletin No. 44— The Mexican Cotton Boll Weevil, 1916. 
 Bulletin No. 4.5 — Annual Report of the State Entomologist for 1915. 
 Bulletin No. 46 — Cotton Variety Tests for Boll- Weevil and Wilt Conditions, 
 
 1916. 
 Bulletin No. 47 — How to Grow Cotton in Spite of Boll-Weevil. 
 Bulletin No. 48 — Annual Report of the State Entomologist for 1916. 
 Bulletin No. 49 — Pecan Insects and Diseases. 
 Bulletin No. 50— Cotton Variety Tests, 1917. 
 Bulletin No. 51 — Annual Report of the State Entomologist for 1917. (In 
 
 preparation.) 
 Circular No. 6 — The Use of Soluble Oils Against San Jose Scale, 1907. 
 Circular No. 7 — The Hessian Fly in Georgia, 1908. 
 
 Circular No. 8 — Experiments for Control of San Jose Scale, 1907-1908. 
 Circular No. 9— The Brown-Tail Moth, 1909. 
 
 Circular No. 11 — Wilt Diseases of Cotton and Its Control, With Suggestions 
 on Seed Selection. 
 
 Circular No. 19 — Boll-AVeevil Quarantine Regulations, 1906. 
 
 Circular No. 20 — General Instructions for Making First-Year Cotton Selections. 
 
 Circular No. 21 — Experimental Dusting and Spraying of Peaches. 
 
 Circular No. 22 — Control of Insects Attacking Stored Products. 
 
 Circular No. 23 — Boll Weevil Quarantine Regulations, 1917. 
 
 Circular No. 24 — Helpful Hints on Dusting Peaches. 
 
 Circular No. 25- — Boll Weevil Quarantine Regulations, 1918. 
 
LIBRARY OF CONGRESS 
 
 lllllllliilllllllllllil 
 
 015 793 431 4