f. // T. S. DEPAR rMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY -CIRCULAR No. 171. L O. HOWARD. F.nlomologia «nd Chief olButemu. FIELD OBSERVATIONS ON SUGAR-CANE INSECTS IN Till: UNITED STATES IN 1912. BY T. E. BOLLOWAY, Entomological Attit .TON : GOVERNMENT PRINTING OFTICE : 191) B UREA V OF ENTOMOLOG Y. L. O. Howard; Entomologist and Chief of Bureau. C. L. Marlatt, Entomologist and Acting Chit flu Absence of Chief '. R. S. Clifton, Executivi Assistant. W. F. Tastet, Chief Clerk. F. H. Chittenden, in charge of truck crop and stored product insect investigations. A. D. Hopkins, in charge of fore it insect investigations. W. D. Hunter, in charge of outhet i field crop insect investigations. F. M. Webster, in charge of cereal and forage insect invt filiations. A. L. Quaintance, in charge of deciduous fruit insect investigations. E. F. Phillips, in charge of &< D. M. Rogers, in charge of preventing spread of moths, field uork. Rolla P. Currie, in charge of editorial u Mabel Colcord, in charge of library. Southern Field Crop Insect Investigations. W. D. Hunter, in charge. W. D. Pierce, J. D. Mitchell, G. D. Smith, E. A. McGregor, Harry Ptnkus, B. R. Coad, G. N. Wolcott, W. A. Thomas, R. \Y. Moreland, C. E. Hester, engaged in cotton-boll weevil invi I iga ' A. C. Morgan, G. A. Runner, S. E. Crumb, D. C. Parman. engaged in tobacco insect investigation. F. C. Bishopp, A. H. Jennings, H. P. Wood, W. V. King, engaged in tick investigate T. E. Holloway, E. R. Barber, engaged in sugar-cane invect investigations. J. L. Webb, engaged in rice in ligations. R. A. CooLEY, D. L. Van Dink, A. F. Conradi, C C. Krumbhaar, collaborators. [Cir. 171] U Circular No. 171. United States Department of Agriculture, BUREAU OK ENTOMOLOGY L. O. HOWARD, Entomologist and Chief of Bureau. FIELD OBSERVATIONS ON SUGAR-CANE INSECTS IN Till; UNITED STATES IN 1912. By T. i: Hoi low it, I ENTROD1 CTION". The results here presented are based on the records of field observa- tions made during the year L912. Though the information on any one insect is fragmentary ;ii best, it has been thoughl desirable t<> issue this reporl for the reason thai bo little is definitely known con- cerning insects affecting sugar cane in the United States thai even a very incomplete treatmenl of the Bubjecl is a contribution to the cur- renl knowledge. \ irvey of the sugar-cane areas of Louisiana and Texas was under- taken during the year, ami this work has been supplemented by some observations made in Mississippi and Alabama. In subsequent reports more attention will be given to the States lasl mentioned, as well as to Georgia and Florida, In it the pro-, of other work in the pasl has rendered it impossible to give these States the attention they deserve. Credit and the thanks of the writer are due to Mr. K. R. Barber, of this bureau, iov making a number of field examinations, mainly the final observations in northern Louisiana and those in Mississippi and Alabama. ■rm. -i G \i: -i wi. moth BORER. Special attention was given to the determination of the percentage of infestation of the moth borer, this being the principal inseel inju- rious to sugar cane in this country. The plan adopted W8S to examine 125 Btalks of sugar cane in a field, choosing the stalks in 5 differenl groups of 25 stalks each. The uninfested and the infested -talks in these groups were counted, and the percentage of infestation was determined from this data. In actual practice this proceeding ' changed to some extent. More than l_'.") stalks were sometimes Ir. 171-13 1 2 l EELD OBSERVATIONS OX SUGAB CANE INSECTS. examined, and sometimes it seemed preferable to examine 75 stalks in each of two fields rather than to concentrate the work on one field. The number of fields examined in one vicinity varied from one to four, depending on the amount of time at the disposal of the inspector. The infestation of the moth borer set ms to be fairly uniform in a given district, and it is believed that I lie results obtained give a good idea of the relative infestation by the insect. Examinations were made from May 24 to November 20, 1012. It was difficult to determine the full infestation of the moth horer during the first part of the season, however, and in the table which follows the results for October and November only are given. Early in the season the cane can hardly be carefully examined without damaging the plant, and the infestation of the moth horer is then small com- pared to the infestation that may he expected later. The dates of inspection are given in the table because the infestation seems nor- mally to increase until the cane is cut. Thus the infestation of a certain field would probably be greater on November 1 than on October 1. Comparisons of the different percentages can be made more accurately if this is kept in mind. Table showing the jk ra ntagt of sugar cane infested by the moth borer at various places i he Souther a States itt 1U12. State. Near town ot city of Parish or county. Date of Inspec- tion. Per cent of inf sta- tion. Louisiana Alexandria Nov. 8 on. 29 Nov. 7 Oct. 2s ....do.... Baton Kouge 78 Iiunkie 56 do 59 81 Mur\ Oct. 31 Oct. 30 Nov. 1 Oct. 17 Nov. 11 Nov. 12 Oct. 7 Oct. 8 Oct. y Nov. 13 Oct. 12 Oct. 11 Oct. 27 Nov. IS Oct 24 Nov. 14 Oct. 28 ...do.... 47 57 St. Mary 4 X. u Orleans 59 Lincoln Caddo 62 Hidalgo 99 88 San Benito do 61 Fort Bind Mississippi Lincoln Hattiesburg Alabama Dallas The foregoing table indicates that the infestation of the moth borer varies from 99 per cent (or practically all canes infested) at a point in the Rio Grande Valley in Texas to per cent (or no canes infested) at places in northern Louisiana, Alabama, and Mississippi, and even at Sugar Land and Victoria, Tex. At Victoria our notes are corrobo- rated by Mr. J. 1). Mitchell, a resident agent of the Bureau of Ento- mology, and planters near there are entirely unfamiliar with the moth [Cir. 171] I hi n 0B8I i:\ \ i 10! borer. Cane baa been grown for - and it ia unlikelj thai anj new varieties have been in in 11 general ion. I ,ema evident from tl thai the moth borer never entered certain restricted districts, while il has probablj I" hnported with shipments of »eed cane to places where an efforl i been made to obtain new and better v< ne. The preset ,,f the moth borer in Louisiana >unted for l>.\ the belief that il . introduced in shipment "!'''-• uhl1, , ,„ ... hi the Rio Grandi \ probably due to accidental inti ductioua from Louisiana or Mexico, provided it is not native to tb pari of Texas. However this maj be, the moth borer is evidently absenl from the sirup-producing regions of Texas and Louisiana, where sugar cane is grown only as an incidental crop, while the insi i> preeenl in the BUgar-producing regions (except at Sugar Land wl ■ Bugar cane is of vital importance and where ne* and better varieties are desired and obtained. The results from examinations in Ala- lia and Mississippi concern sirup-producing communities, ai i esults from Texas and Louisiana. These findings go to Btrengthen the position that introductions e should be made with greal care if injurious re to be excluded. A most noteworthy result of the examinations during the year is the discovery of eggs of the moth borer I by the hymen •us parasite 2 mma minutum Riley, by Mr. Gilbert E. Bodkin, Government economic biologist of British Guiana, ii.-.,. Examining sugar cane with the writer ai Audul p , ans, in September, he found the black egg m the moth borer on the leaves of the planl B miliar with the work of the parasite in British Guiana he was sure that tl parasitized. Parasites were afterwards reared from the eggs by the writer, and they were found to be of th< ned, which occurs in many place- in this and other countries. The parasite, however, had not previously been reared from the moth borer iu the United S Later the writer found parasitized eggs of the moth borer Brownsville, Tex., Donna. Tex., Donaldsonville, La., -1 Franklin, The larvae of a predaceous hectic were found on sugar cane by Mr. !•".. R. Barber, near Montgomery, A October 26, and by the writer near Baton Rouge, La .ami La Fayette, La., in October, and near San Benito. Tex., in November. These larvae were not i to attack the borer, though they may do - Evidences of larval pai number of places, but these are somewhat doubtful. 1T1] 4 FIELD OBSERVATIONS OX SUGAR-CANE INSECTS. THE SUGAR-CANE MEALYBUG. (Pseu/docorru.s calceolaria Mask.) The examinations to determine the infestation of the mealybug were made chiefly in connection with the work on the moth borer. The mealybug appeared in small numbers at the experiment station at Audubon Park during the summer of 1912, and by November 26 it was difficult to find a single stalk of the cane then on the fields which was entirely free of the insect. Near Poydras, St. Bernard Parish, La., a few mealybugs were found on one stalk of cane on September 10. On September 12 a small infestation was found in Jefferson Parish, near New Orleans (on St. Martin plantation). The mealybug in fairly large numbers was found by Mr. E. R. Barber at English Turn, Plaquemines Parish. La., on September 24. Near Franklin, La., the writer found a slight infestation on October 31. The green fungus which attacks the mealybug was observed at two places in Orleans Parish, La. The mealybug was discovered by the writer at Brownsville, Tex., for the first time on October S. A rather heavy infestation occurred on a limited number of canes of various new varieties at the experi- ment station. The bisect had evidently been brought hi with the cane from Louisiana or the Tropics. The infested cane was soon after destroyed by those in charge in an effort to eradicate the mealybug from the experiment station grounds. It is evident that the mealybug has infested only a limited territory in the United States. Precautions should be taken to prevent its spread to uninfested regions. The problem of the mealybug is com- plicated in certain parts of Louisiana, where the Argentine ant (Irido- myrmc.r humilis Mayr) also occurs, as the two species are of benefit to each other, and the ant aids in the spread of the mealybug. THE SUGAR-CANE WEEVIL BORER. Concerning the weevil borer we quote our remarks in another circular, 1 which are as follows : A note in the possession of the •writer records a weevil as having been reared from young shoots of sugar cane which were collected at Fairview Plantation, Berwick. La., on April 28, 1910, by Mr. D. L. Van Dine. Mr. Van Dine found the lame just above the surface of the ground. Mr. E. R. Barber of this office states that he found pupae of weevils in the sugar cane at Audubon Fark. New Orleans, in 1911. During the early summer in 1912 the writer found weevil borers in the young sugar-cane plants at Audubon Park and at the experiment station at Brownsville. Tex. The 1 Insects Liable to Dissemination in Shipments of Sugar Cane. By T. E. Holloway. Cir. 165, Bur. Ent., U. S. Dept. Agr., 1912. [Cir. 171] FIELD OBSERVATIONS OS BUOAR-CAN1 IN8E( TO. D Qi fouu ' na^ ill'' were in the lai bble (.in.. I., l. u the nurface "i the ground, and Dear the poinl where il" left the old etubble in plant caneal Audubon Parli the weevil lai und below tin- surfai •■. and near the poinl where the young plant joined the seed i The Ian e were from one-eighth i te fourth oi an Inch In lengtb Bonn borer was found in the middle of the stem, while in other cases the borera were one aide of the stem. The injur) to the plant [alike the "dead heart 'caused by our moth borer, it seems probable that the moth borer ia blamed i"i some oi the injury caused by the weevils. Very likely th era have ' n Introduced In shipment e from the Tropica They are small, and tlnir w.rk ia lui r. i to find, so that they d easily have escaped the eye of the average person ila have been found up to date that there may be do oi casion for alarm, while on the other hand they may Increase In numbei become b Till. PALL AltMY WORM. Laphygmafrugiperda S a \ Following the wel weather of tin' spring of 1912 an outbreak of tin' fall anny worm, or southern grass worm, was noticed in the Southern States. Corn, rice, ami forage crops suffered more than sugarcane, hut i>m> field of cane thai tame under the writer's observa- tion was ruined by this or a nearly related specie-. This held was near La Fayette. La., and was examined on .Inly 20, I'M-'. The land was comparatively low ami undrained, thus providing a suitable place for the development of the "grass worm." which prefers a soil. The characteristic work of the larvaa was observed, though no larva 1 were found. LarvSB, however, were found attacking SUJ cane at Audubon Park. New Orleans, during July, 1912. In most cases it seems that no great injury from this Bpeciea was Buffered by Bugarcane, and the plants recovered so completely that in the grinding season the injury was hardly perceptible, and only a few leaves could ordinarily he found showing traces <>f the work of the larvae. I III. -i i; LR-CANE BEETLE. No definite records have been obtained during the year regarding the Bugar-cane beetle, and it is probable that it has done very little damage this season. May beetles (Lachnosterna spp.) are also known to attack su«rar cane, hut no injury due to them was observed during the year, ami Very few adults of the beetles were seen at New Oilcan-. [Clr. 171] FIELD OBSERVATIONS OX SUGAR-CANE INSECTS. THE SUGAR-CANE APHIDID. Winged and wingless forms of a dark brown aphidid, or plant louse, were observed on sugar cane at Audubon Park, New Orleans, on July 29, 1<)12, and at various times thereafter. They were attended by the Argentine ant in the same way as the mealybug is attended by this species. Very little is known concerning tbis aphidid. It is found in small colonies on the outside of the leaf axils on the cane plant, and apparently works in a manner somewhat similar to that of the mealybug, though it has been observed on the leaves of the cane rather than on the stalks themselves. In large numbers tbis species might be injurious to the eyes of cane for planting. These aphidids were also found near Donaldsonville, La., Franklin, La., llarlingen. Tex., Morgan City, La., and Poydras, St. Bernard Parish, La. INSECTS OF MIXOR IMPORTANCE. ANTS. The large red ant of Texas (Pogonomyrmex barbatus Smith), usually called the agricultural ant, was recorded during the year as attacking sugar cane. Near Brownsville, Tex., on June 12, the writer observed ants of this species busily gnawing a few young cane plants. The sound they made was similar to that of a gentle shower of ram. The ant- bad eaten the leaves of plants about 2 feet high, as well as the entire tops of two little plants about one-eighth inch hi diameter. This seems to be an exceptional habit on the part of the agricultural ant. Another species of ant was found nesting in holes in cane stalks made by the moth borer and in the spaces between the leaves and the stalk-. This observation was made near Brownsville, Tex., on Octo- ber 7, 1012. These ants should not be confused with the Argentine ant, which is of prime importance in its symbiotic relationship with mealybugs, scale insects, and aphidids. LEAFHOPPERS. Leafhoppers in very small numbers were observed several times during the season on sugar cane, but no injury due to them could be detected. FROGHOPPERS. Mr. Gilbert E. Bodkin and the writer found froghoppers on sugar cane, weeds, and grass near Poydras, St. Bernard Parish, La., on September 10. 1012. The froghoppers start on rank growth and then . 171] Ml i |. OB I >:' IT1< OAR-CANE 1 7 transfer their attention I cane Forth] reason the fields should be kepi free of weeds and I peciallym moist situatioi humid climate is favorable to the development of these ins< ■ The writer found termites or "white ants" in sugar cane which bad been cut into pieces of three joints each and planted. <>u June 12, 1912, when some of the cane wa dug up and examined, the shoots from it were apparently weak and some of tl yes had nol germinated. The cane was plantod neai Brownsville, Tex . and had been imported from Porto Rico, but the writer believes that the termites were probablj native to this country and that they attacked the cane readily, being attracted by the many cuts. Ii seems inad- visable from the entomological standpoint to cut cane in Bmall pie before planting, as many insects may easily gnaw into the Btalks through the unprotected ends. On August 9, 1912, Mr. E. R. Barber found grasshoppers very abundant in the cane fields near Sugar Land, Tex. Many strip] leaves, due to their work, were seen. The writer visited Sugar Land on October 12, but found no grasshoppers at that time. The cane ned to have recovered from the injury it had suffered earlier in the season from these insects. A grasshopper in the act of gnawing a cane leal' wa- observed near Baton Rouge, La. < ONCLl SIONS. The peculiar weather during the season of L912 probably accounts in |>art at Least for certain unexpected developments in insect life during the year. A long ami cold winter was followed in Louisiana by a wet spring. Breaks in the lever of the Mississippi River caused vast area- of land to he flooded, ami the excess of water complicated matter- further. We find a -low development of the moth borer ami the mealybug, which are tropical species and evidently require a greater amount of warm weather than our native insects. A- to the Bugar-cane hectic, the statement ha- been math' by some plant that this inseel does most damage in dry seasons and on high, sandy soil-, 30 that we may believe that the wet weather retarded it- development. The fall army worm, or southern grass worm, on the contrary, i- more injurious during wet weather, which will account for it- extraordinary abundance during the summer ^>\' 1'"-'. Practically no moth borers or mealybugs were found in the dis- trict near Morgan City. La., which had been overflowed some months (Cir. 171] 8 FIELD OBSERVATIONS ON SUGAR-CANE INSECTS. previous to our observations. This indicates that these insects may possibly be controlled by flooding or excessive irrigation. Though these inferences are mainly, perhaps, of scientific interest, they may at some time be useful in an economic way. More impor- tant from the planter's point of view, however, is the evidence of the uneven distribution of the principal insects which are injurious to sugar cane. It seems that with reasonable caution in the ship- ment of cane the spread of most species, at least, can be curtailed if not altogether prevented. The number of species which were detected injuring cane is per- haps surprising, and it is possible that still other species will be discovered as the work progresses. Some of the species are appar- ently of no great importance, though there is a possibility that the weevil borer and the froghopper, which are now rare, may increase in numbers and become formidable pests. The aphidid, also, which is rather widely distributed, is to be regarded as an insect which may be capable of considerable injury. Approved : James Wilson, Secretary of Agriculture. Washington, D. C, January 18, 1913. [Cir. 171] ADDITIONAL COPIES of this publication ■Li- may be procured from the Superintend- ent of Documents, Government Printing Office, Washington, D. C. , at 5 cents per copy UNIVERSITY OF FLORIDA 3 1262 09216 5389