* Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY— BULLETIN No. 109. L. O. HOWARD, Entomo'ogist and Chief of Bureau. PAPERS ON INSECTS AFFECTING VEGETABLES. I. THE HAWAIIAN BEET WEBWORM. By H. O. MARSH, Agent, Engaged in Sugar-Beet and Truck-Crop Insect Investigations. II. THE SOUTHERN BEET WEBWORM. By F. H. CHITTENDEN, In Charge of Truck-Crop and Stored Product Insect Investigations. III. THE IMPORTED CABBAGE WEBWORM. By F. H. CHITTENDEN, In Charge of Truck-Crop and Stored Product Insect Investigations, and H. O. MARSH, Agent. IY. A LITTLE-KNOWN CUTWORM. By F. H. CHITTENDEN, In Charge of Truck-Crop and Stored]Product Insect Investigations. V. ARSENITE OE ZINC AND LEAD CHROMATE AS REMEDIES AGAINST THE COLORADO POTATO BEETLE. By FRED A. JOHNSTON, Entomological Assistant. VI. THE SUGAR-BEET WEBWORM. By H. O. MARSH, Entomological Assistant. VII. THE HORSE-RADISH WEBWORM. By H. O. MARSH, Entomological Assistant. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1916, BUREAU OF ENTOMOLOGY. L. 0. Howard, Entomologist and Chief of Bureau. C. L. Marlatt, Entomologist and Assistant Chief of Bureau. E. B. O'Leary, Chief Clerk and Executive Assistant. F. H. Chittenden, in charge of truck crop and stored product insect investigations. A. D. Hopkins, Forest Entomologist. W. D. Hunter, in charge of southern field crop insect investigations. , in charge of cereal and forage insect investigations. A. L. Quaintance, in charge of deciduous fruit insect investigations. E. F. Phillips, in charge of bee culture. A. F. Burgess, in charge of gipsy moth and brown-tail moth investigations. Rolla P. Currie, in charge of editorial icork. Mabel Colcord, in charge of library. - Truck Crop and Stored Product Insect Investigations. F. H. Chittenden, Entomologist in charge. C. H. Popenoe, T. H. Jones, M. M. High, F. A. Johnston, and D. E. Fink, entomological assistants. H. 0. Marsh, F. B. Milliken, C. F. Stahl, Frank R. Cole, A. B. Duckett, B. L. Boyden, R. E. Campbell, W. H. White, and Pauline M. Johnson, Scientific assistants. Neale F. Howard, Specialist. W. N. Dovener, Expert. CONTENTS Page. The Hawaiian beet web worm {Hymenia fascialis Cram.) H. 0. Marsh. . 1 Introductory 1 Food plants and injury 2 Life history and habits , 3 Natural enemies 7 Experiments with insecticides 7 Description of the earlier stages H. G. Dyar. . 11 Appendix ' F. H. Chittenden . . 12 Description and synonymy 12 Distribution 14 History 14 Bibliography 15 The southern beet web worm (Pachyzancla bipunctalis Fab.) . .F. E. Chittenden. . 17 Injurious occurrences and notes on habits 17 Descriptive 19 The moth 19 The egg 20 The larva 20 The pupa. 20 Distribution 21 Historical and biological notes 21 Natural enemies 21 Associated insects 21 Remedies 22 Paris green 22 • ' Dragging the log " 22 The imported cabbage web worm (Hellula undalis Fab.)...i<\ H. Chittenden and H. 0. Marsh 23 Introduction, spread, and ravages 23 Description and life-history notes 27 The moth 27 The egg and oviposition 28 The newly hatched larva 29 The full-grown larva 29 ■ The pupa : 29 Distribution 30 Food plants 30 Natural enemies 31 The imported cabbage web worm in Hawaii 32 Life history and habits 34 Natural enemies in Hawaii 37 Experiments with insecticides 38 Experiment in screening a seed bed 41 Conclusion 41 Recommendations for control 42 Bibliography 44 in IV PAPEES ON INSECTS AFFECTING VEGETABLES. Page A little-known cutworm (Porosagrotis vetusta Walk.) F. H. Chittenden.. 47 Injurious occurrence 47 Results from applications of arsenate of lead 49 Description 50 The moth 50 The larva 50 Distribution 50 Natural enemies . 51 Arsenite of zinc and lead chromate as remedies against the Colorado potato beetle < Fred A. Johnston. . 53 Spraying experiments with arsenite of zinc and lead chromate in compari- son with other arsenicals 53 Spraying experiments with arsenite of zinc of different strengths 55 A report of progress regarding the sugar-beet web worm (Loxostege sticticalis L.), H.O. Marsh.. 57 Introduction 57 General appearance of the sugar-beet web worm and nature of attack 58 Life history and habits 59 Character of injury 61 Natural enemies 62 Other checks 63 Experiments with remedies 63 Spraying machinery 66 Cost of spraying 69 Conclusion 70 The horse-radish web worm (Plutella armoracia Busck) H. 0. Marsh. . 71 Introduction 71 Occurrence in Colorado 71 General appearance and habits 72 Life history 73 Rearing records 73 Egg-laying record 75 Natural enemies . . . 75 Experiments with insecticides 76 Recommendations for control , 76 Conclusion 76 Index 77 LLUSTRATIONS PLATE. Page. Plate I. Fig. 1. — Geared traction sprayer, suitable for the treatment of sugar beets against the Hawaiian beet web worm 8 Fig. 2. — Geared traction sprayer in operation in sugar-beet field 8 TEXT FIGURES. Fig. 1. The Hawaiian beet web worm {Hymenia fascialis) : Female moth 3 2. The Hawaiian beet web worm: Egg. larva, pupa, details 4 3. The southern beet webworm (Pachyzancla bipunctalis) : Moth, larva, pupa, details 19 4. The imported cabbage webworm (Hellula undalis): Adult, larva, pupa. 28 5. The imported cabbage webworm: Wing venation; head and antenna. . 28 6. Exorista pyste. a parasite of the imported cabbage webworm 31 7 . Small compressed-air sprayer 38 8. Porosagrotis vetusta: Moth, larva 50 9. The sugar-beet webworm (Loxostege sticticalis) : Moth 58 10. The garden webworm (Loxostege similalis): Moth, larva, pupa, details. . 58 11. A medium-sized sugar-beet plant defoliated by the sugar-beet web- . worm in July 60 12. Sugar beets defoliated by the sugar-beet webworm in July 61 13. Large sugar-beet plants, showing defoliation and weakened roots due to attack by the sugar-beet webworm in August 62 14. Field of young sugar beets destroyed by the sugar-beet webworm in June 63 15. Barrel sprayer suitable for use against the sugar-beet webworm 64 16. Barrel sprayer in action against the sugar-beet webworm 65 17 . Four-row attachment for beet sprayer 67 18. Four-row attachment for beet sprayer 67 19. Four-row attachment for beet sprayer 67 20. Geared traction sprayer suitable for use against the sugar-beet webworm . 68 21. Geared traction sprayer in action against the sugar-beet webworm 68 22. Filling a traction sprayer for spraying against the sugar-beet webworm . . 69 23. Type of Vermorel nozzles suitable for spraying sugar beets against the sugar-beet webworm 69 24. The horse-radish webworm (Plutella armoracia): Adult or moth, side view and with wings spread 72 25. The horse-radish webworm: Larva, lateral and dorsal views 72 26. The horse-radish webworm: Pupa 73 27 . The horse-radish webworm : Cocoon 73 ERRATA. Page 33, line 7, for Agrostis read Agrotis. Page 72, line 14, for scale like read scale-like. Page 76, last sentence, read, In this garden the larvx have evidently been prevented by a hymenopterous parasite from causing much damage, and at present no artificial control measures are necessary. v U. S. D. A., B. E. Bui. 109, Part I. T. C. & S. P. I. I., November 6, 1911. PAPERS ON INSECTS AFFECTING VEGETABLES. THE HAWAIIAN BEET WEBWORM. (Hymenia fascialis Cram.) By H. O. Marsh, Agent, engaged in Sugar-Beet and Truck-Crop Insect Investigations. INTRODUCTORY. During the latter half of 1910 the author was engaged in a study of insects affecting truck crops in the Hawaiian Islands. The enemies of beets and of the so-called spinach (Amaranthus sp.) were among the insects which were studied. The species injurious to these two crops had previously received very little study from an economic standpoint, and the necessity of such study was further enhanced by the fact that a land company was experimenting with sugar beets on the island of Lanai 1 with the intention of growing this crop on a large scale, if it should offer promise of becoming profitable. In the vicinity of Honolulu, on the island of Oahu, vegetables are grown in commercial gardens, managed by Chinese or Japanese. In a general sense, these growers may be considered "good farmers" although they have little regard for the necessity of clean culture and seldom make any intelligent effort to combat insect pests or plant diseases. In the rare cases where an effort is made to cope with such troubles, the methods employed are extremely crude. Practically all cultivation is done by hand, except that occasionally the water buffalo is used for plowing the land before the crops are planted. From the Oriental point of view this plowing is considered sufficient if the surface of the ground is scratched to the depth of a few inches. The fertilizing material used is in liquid form. It is prepared by soaking stable manure or other refuse material in water and is applied directly about the plants. Table beets and " spinach " are produced exclusively for the local market. These vegetables are grown in beds, in a peculiar manner, which Mr. E. M. Ehrhorn has aptly designated "the graveyard style." The beds, which are very often about 10 yards long by 1 1 The sixth largest island of the group. 2 INSECTS AFFECTING VEGETABLES. yard wide, are mounded up about 6 to 8 inches above the surrounding surface, the top is leveled, and the seeds are planted on these elevated plats, which have an appearance very suggestive of graves. Although the climate is rather humid the normal rainfall, at Honolulu, is so light that irrigation is necessary to produce a crop. Practically all the gardens have an abundant supply of artesian water, but, owing to the manner in which the beds are elevated, it is impossible to run the water between the rows of plants, and as a result they have to be watered by hand. This is accomplished by dipping up the water in large watering cans and sprinkling it over the beds. It would seem that this slow and laborious method of irri- gation could be eliminated if the beds were prepared in a more up-to- date manner. The so-called spinach is not the plant which is recognized by that name in mainland markets, but is a species of Amaranthus. The leaves and stems of the young and tender plants, when properly cooked, make fairly palatable " greens." FOOD PLANTS AND INJURY. The most conspicuous enemy of this class of vegetables is the Hawaiian beet webworm (Hymenia faseialis Cram.). In the Ha- waiian Islands the larvae of this species include among their food plants table beets, sugar beets, stock beets ( mangel- wurzels), several species of Amaranthus, Euxolus, purslane (Portulaca oleracea), cucumbers, and chenopodiaceous weeds. Among the wild food plants, Amaranthus is the favorite. These weeds grow in abundance along fences and in neglected spots, and it frequently happens that the plants are so completely stripped of foliage that large patches of them die. Cultivated Amaranthus is likewise severely damaged. Beets are a close second in attractiveness, and it is not unusual to see beds of this vegetable with nothing remaining of the foliage but the petioles. When infestation is very severe the plants are oc- casionally killed outright, and even when the larvae are less abun- dant the infested beets are stunted in growth and injured in quality. Sugar beets are attacked as readily as the table variety. During the latter part of August, 1910, the author received some sugar beets from the experimental plats on Lanai, from which practically all the foliage had been stripped, and it was reported that all the beets in the plats were in a similar condition. This webworm is the most serious insect pest which menaces the production of sugar beets in Hawaii, and unless it is controlled it is unlikely that this crop can be profitably grown. Cucumbers are apparently only rarely attacked and the occasional larvae which were found infesting this cucurbit were doubtless feeding on it because more attractive food was not avail- able. Portulaca is commonly attacked but apparently is not so favored a food as Amaranthus or beets. THE HAWAIIAN BEET WEBWORM. LIFE HISTORY AND HABITS. All stages of this pest can be found throughout the year. The moths (fig. 1) are usually to be found in abundance among the foliage of Amaranthus, beets, or other low-growing plants. During the day they remain concealed, usually on the underside of the leaves, but when dis- turbed they fly readily. They are but rarely attracted by lights. The scale-like iridescent eggs (fig. 2, a) are almost invariably deposited on the underside of the leaves. They are placed singly, in pairs, or in rows of five or more. On beet leaves, the favorite place for depositing eggs is along the midrib and larger veins. As many as 40 eggs, which had been deposited in the field under normal condi- tions, were counted on a single beet leaf. The eggs have been ob- Fig. 1. — The Hawaiian beet webworn (Hymenia fascialis) (Original.) Female moth. Enlarged. served to hatch in 4 days. The young larva? feed on the lower sur- face of the leaves. On beets, and probably on other plants, the larvae, except when nearly mature, consume only this surface. This habit of remaining on the underside of the leaves, without eating through the upper epidermis, adds to the difficulty of successfully treating this pest with insecticides. (See larva and details, fig. 2, b-e.) In some cases the larvae spin light webs, under which they rest. This web-forming habit is not very pronounced, and it is not unusual to find hundreds of larvae without any webs whatever. Under normal conditions the larvae reach maturity in from 9 to 13 clays. They then leave the plants, burrow slightly beneath the surface, and form firm, compact, oblong cocoons of webbed-together INSECTS AFFECTING VEGETABLES. grains of earth. From the time of hatching until fully mature, the larvae are pale green, but while engaged in constructing their cocoons (fig. 2, h) , they change to a reddish pink. They usually pupate about 2 days after entering the soil, and the adults issue from 7 to 13 days later, thus completing a generation in from 22 to 31 days. (See pupa and details, fig. 2, /, g.) The climate of Hawaii is so equable that this pest is enabled to breed continuously, and it is possible that ten or twelve gen- erations might be produced an- nually. Owing to the overlap- ping of broods and to the fact that eggs, larvae, pupse, and adults are to be found at almost any time, it is practically impos- sible to work out the number of generations for a given year from field observations alone.1 Beginning in July, 1910, and continuing past the middle of January, 1911, the author reared this species through six genera- tions in the insectary. The rec- ords of five of these generations ren below. The actual Fig. 2. — Hawaiian beet webworm : a. Egg on leaf ; 6, larva, dorsal view ; c, larva, bead and first tboracic segment ; d, abdominal segment, lateral view ; e, anal segment ; /,, pnpa, lateral view ; g, cremaster ; h, co- coon. All enlarged. (Original.) and is not included in this paper. are giv first (July- August) generation was reared from larvae which were collected in the field, and as the egg stage was. not ob- tained the record is incomplete For the sake of convenience the August- September generation is mentioned as the first, although, in reality, it was the second, in direct line of. descent. The five following generations are FIRST GENERATION. August 20. — At this date four moths were collected in the field and confined in a cage. August 25 First eggs deposited. August 29 The eggs hatched. September 7 First larvae reached maturity. September 9 First larva? pupated. September 16 First adults issued. 1 It is not probable, however, that more than six generations can be produced succes- sively, beginning with one pair of moths, since insects in general, in the writer's experience, always undergo a resting stage — sometimes two. — F. H. Chittenden. THE HAWAIIAN BEET WEBAVORM. 5 From the above record the stages are as follows: Days. Egg stage 4 Larval stage 11 Pupal stage * : 7 Total 22 SECOND GENERATION. September 16 Adults issued. September 18 • First eggs deposited. September 22 The eggs batched. October 3 First larva? reached maturity. October 5 First larvae pupated. October 15 First adults issued. From the above record the stages are as follows: Days. Egg stage 4 Larval stage 13 Pupal stage 10 Total 27 THIRD GENERATION. October 15 Adults issued. October 17 1 First eggs deposited. October 21 _The eggs hatched. November 1 First larvae reached maturity. November 3 First larva? pupated. November 12 First adults issued. November 13 ' More adults issued. From the above record the stages are as follows : Days. Egg stage 4 Larval stage !__j 13 Pupal stage 9 Total 2(1 Curiously enough the first moths. 10 in number, which issued No- vember 12. failed to deposit any eggs, so the first eggs deposited by moths which issued the following day (Nov. 13) were retained to commence the succeeding generation. FOURTH GENERATION. November 13 Adults issued. November 16 ^ First eggs deposited. November 20 The eggs hatched. December 2 First 1 a rvte reached maturity. December 5 First larva? pupated. December IT First adults issued. 8481°— Bull. 109, pt. 1—11 2 6 INSECTS AFFECTING VEGETABLES. From the above record the stages are as follows : Days. Egg stage 4 Larval stage 15 Pupal stage 12 Total 31 FIFTH GENERATION. December 17 Adults issued. December 19 First eggs deposited. December 23 The eggs hatched. January 4 First larvae reached maturity. January 6 First larva? pupated. January 19 First adults issued. From the above records the stages are as follows : Days. Egg stage 4 Larval stage 14 IMi pal stage 13 Total 31 These records were obtained in an open-air insect ary at Honolulu. The moths were confined in open-wire cages, which contained an inch or more of moistened, sterilized soil. Beet or Amaranthus leaves, upon which the eggs were to be deposited, were placed in the cages and food was supplied the moths by putting in wads of ab- sorbent cotton, which had been saturated in molasses and water. This food was evidently greatly relished. The moths were very " wild " and flew about very actively whenever the cages were ap- proached. Copulation evidently took place at night, as during the several months that the species was kept under daily observation, in the insectary and field, no mating pairs were observed. Owing to the failure to obtain mating pairs and to the fact that it is difficult to distinguish the sexes when the moths are fluttering wildly about in the cages, no individual egg-laying records were obtained. In one case three newly, emerged and unfertilized female moths were placed in a cage and supplied with molasses as food. They livecl 10 days, and during this time deposited 300 eggs. Such *a record is not con- clusive, but it indicates that each female is capable of depositing at least 100 eggs. This is doubtless far short of the actual number of eggs that one female could deposit under normal conditions. THE HAWAIIAN BEET WEBWOEM. Temperatures at Honolulu during the time the species teas reared. Month. Minimum tempera- ture. Maximum tempera- ture. Average mean tem- perature for entire month. 1910. July °F. 69 66 69 65 66 62 58 °F. 84 85 85 84 84 80 79 °F. 76.5 76.8 77.0 75.3 74.6 71.2 70.0 September November | December 1911. j January NATURAL ENEMIES. At various dates larva? were collected in the field and confined in cages in the insectary. In this way three species of hymenopterous parasites were obtained. These were Limnerium hawaiiense Cram., Chelonus blackbumi Cram., and Cremastus hymenice Vier. L. hawaiiense was obtained in greatest numbers during August and September, while C. blackbumi apparently became more abundant during December. C. hymenice was 'reared only in small numbers and at all times appeared to be more rare than the other species. Xo predaceous enemies were actually .observed feeding on the Hymenia larvae or pupae, but on several occasions a species of wasp (Polistes hebrwus Fab.) was seen buzzing about infested plants. During the warmer months this wasp and allied species are efficient enemies of the common cabbage worm (Pontia rapce L.), and it is not improb- able that they also occasionally kill Hymenia larvae. On the whole, the natural enemies apparently do not reduce the number of Hymenia larvae sufficiently to be of much practical value. EXPERIMENTS WITH INSECTICIDES. During the fall of 1910. an opportunity was taken to make some experiments against the Hymenia larvae with insecticides. The ex- periments were as follows: Experiment No. 1. — Paris green, 4 pounds, and lime, 4 pounds, in 100 gallons of water. September 1, three beds of table beets, each 10 yards in length and 1 yard wide, were sprayed with about 2 gal- lons of this mixture. The application was made with a portable, compressed-air sprayer, which was fitted with a short extension-rod elbow and a Vermorel type nozzle. The mixture was applied chiefly to the upper surface of the leaves and it adhered very well. The weather at the time of the application was hot and clear and without a breeze. The following day all the larvae were alive, except those on ac- casional. leaves which were poisoned on the underside. Thirty-three 8 IXSECTS AFFECTING VEGETABLES. live larvae were counted on the underside of one leaf. These beds were examined daily, and on September 7 it was concluded that the experiment was a failure, as the larva?, except on the leaves which had been thoroughly sprayed on the underside, were unharmed. It was noted that on leaves which had been but partially sprayed on the underside the larvae avoided the poisoned portion but continued to feed on the part which had been missed by the spray. The failure of this experiment was due to the habit the larvae have of feeding on the underside of the leaves, without eating through the upper epi- dermis. The mixture used in this experiment burned the partly con- sumed leaves slightly but caused no extensive injury. Experiment No. 2. — Paris green. 2 pounds, and whale-oil soap, 8 pounds, in 100 gallons of Avater. September 7, three beds of table beets, each 10 yards in length and 1 yard wide, were sprayed with about 3 gallons of this mixture. The same apparatus was used as in experiment No. 1. A particular effort was made to wet the under sur- face of the leaves thoroughly. The mixture adhered perfectly and an extremely even distribution of the poison was obtained. The weather was hot and clear. The following day nearly all the larvae were dead and the few individuals which remained alive appeared very sick. September 10, the beets were free of larvae and the foliage showed no burning by the spray mixture. Two weeks later the sprayed plants were still free of larvae, while beets in adjoining (check) beds were badly in- fested. This experiment plainly demonstrates that if the spray is applied properly, i. e., to the underside of the leaves, it can be de- pended on to control this pest. In addition to the experiments with Paris green, a few preliminary and somewhat inconclusive tests were made with arsenate of lead, lead chromate, and lime-sulphur solution. For the sake of con- venience these will be classed as experiments. Experiment No. 3. — Arsenate of lead, 1^ ounces, and molasses, 1 quart, in 1| gallons of Avater. This mixture was experimented Avith as a poisoned bait for the melon fly (Dacus cuewrbitm Coq.), and was not originally intended for use against the Hawaiian beet ATebworm. September 7, a patch of Amaranthus, badly infested by laiwae varying in size from those recently hatched to others nearly mature, was sprayed AAith some of this mixture. The spray was applied very thoroughly to the upper and loAATer surfaces of the leaves with the same apparatus as used in experiment No. 1. The folio Aving day the laiwae Avere unharmed. The leaATes showed a good even coat of the arsenate. The sprayed plants were kept under daily observation until September 13, at which date they Avere destroyed. On the 9th and 10th of September it Avas noted that the larvae Avere groAving nicely and appeared to relish the poison-coated leaves. Bui. 109, Part I, Bureau of Entomology, U. S. Dept. of Agriculture. Plate I. Fig. 1.— Geared Traction Sprayer Suitable for the Treatment of Sugar Beets Against the Hawaiian Beet Webworm. (Original.) ■dHB*~ — - ; f "7- %y '■ " *- !*__ W • ■ Fig. 2.— Geared Traction Sprayer in Operation in Sugar-beet Field Against the Hawaiian Beet Webworm. (Original.) THE HAWAIIAN BEET WEBWORM. 9 September 12, all the larvae which had not matured were still feed- ing and showed no ill effects from their diet of arsenate of lead and Amaranthus leaves. The spray mixture caused no injury to the foliage. In this test a standard grade of arsenate of lead was used at the rate of 6J pounds in 100 gallons of water, and it is difficult to under- stand why it failed to kill the tender Hymenia larva?. Of course, such a test as this can not be considered conclusive, but it would indi- cate that less effective results would be obtained with arsenate of lead than with Paris green. Experiment No. 4- — Lime-sulphur solution, 1 gallon, in 15 gallons of water. November 1, a few infested beets were sprayed with a small quantity of this solution. A thorough application was made to the upper surface and underside of the leaves with an atomizer. Larva? which were drenched with the solution appeared to die promptly. The weather was hot and clear at the time of the application. Two days later the larvae had been reduced somewhat in numbers but there were still plenty of living specimens present. Some of the leaves were severely burned. November 5, the coat of lime was still very good. The larvae were feeding on the coated leaves and were appar- ently unharmed. This solution apparently killed only the larvae which were thoroughly drenched at the time of the application. The beet foliage was severely burned, and on the whole the results were not promising. Experiment No. 5. — Lead chromate, 2 ounces, in 8 gallons of water. December 16, a few infested beets were sprayed with a small quan- tity of this mixture. The application was made to the upper and lower surfaces of the leaves with an atomizer. The mixture ap- peared as a yellow coating on the leaves and adhered very well. The weather was hot and clear. Three days later the larva? were still alive, but had ceased feeding, and were clinging to the leaves in a listless manner. During the following two or three days they dropped to the ground and died. The sprayed foliage showed no burning. It is not possible to form a definite conclusion from this meager test, but it indicates that lead chromate at this strength is very slow in its killing effects. In another similar test lead chromate was used on beets at the rate of 2 ounces in 4 gallons of water. LTnfortunately an illness of the author prevented the making of observations as to the effect of this strength on the larvae. Ten days after the application it was noted that two heavy rains had failed to wash the coat of poison from the leaves and that no burning had resulted. It is evident that this new insecticide has some good points, and it should be given a thorough trial. 10 INSECTS AFFECTING VEGETABLES. The results of the experiments may be summarized as follows : Experiments with insecticides. Experi- ment No. Date. Insecticide used. Effect on larvse. Injury to foliage. Remarks. 1 2 3 1910 Sept. 1 Sept. 7 ...do Nov. 1 Dec. 16 Paris green, 4 pounds, and lime, 4 pounds, in 100 gal- lons of water. Paris green, 2 pounds, and whale-oil soap, 8 pounds, in 100 gallons of water. Arsenate of lead, lh ounces, and molasses, 1 quart, in 1J gallons of water. Lime-sulphur solution, 1 gallon, in 15 gallons of wa- ter. Lead chromate, 2 ounces, in 8 gallons of water. Ineffective Absolutely ef- fective. * Slight. . . None ...do.... The poor results were due to the poison being applied to the upper surface of beet leaves where the larvae failed to reach it. Spray applied properly to the under surface of beet leaves. Applied to the upper and lower surface of Amaran- thus leaves. There is no apparent reason for its fail- ure to kill the larvae. Applied to beet leaves. A 4 do Severe . . None 5 Possibly effec- tive. few larvae were killed by contact with the solution. Applied to beet leaves. The poison was very slow in its killing effect. It will be seen from the record of experiment No. 2 that this web- worm can be effectively controlled on beets with Paris green. When this poison is applied at the rate of 2 pounds in 100 gallons of water it will not burn beet foliage and in this formula it is better to omit lime and use whale-oil soap. The soap serves as an effective adhesive agent and when it is used the poison is very evenly distributed over the leaf surface. As " spinach " is used as food by human beings while the plants are still young and tender, it is obvious that it would be unsafe to spray this crop with an arsenical. Instead of an arsenical it is recommended that the following nicotine-soap combination be used on spinach: Nicotine sulphate^ 1 fluid ounce. Whale-oil soap 4 ounces. Water 4 gallons. This formula was successfully used by the author at Honolulu, against the common cabbage worm (Pontia rapce Linn.), the larva of the diamond-back moth (Plutella maculipennis Curtis), a looper (Autographa precationis Guen.) , and the beet army worm (Caradrina exigua Hbn.). It has also been used effectively against several species of aphides or plant-lice and thrips. Although this formula has not been actually tested on Hymenia larvse, there is no reason to believe that it would not prove entirely effective. For treating moderate- sized plats in gardens a portable com- pressed-air sprayer or a bucket pump will give good results. The spraj^er should be fitted with a short extension rod, an elbow, and a nozzle of the Vermorel type, which will deliver a fine, mist-like THE HAWAIIAN" BEET WEBWORM. 11 spray. The elbow makes it possible to coat the underside of the leaves thoroughly. It is essential to bear in mind that, unless this surface of the foliage is thoroughly covered with the poison, the spraying will be ineffective. In the gardens about Honolulu, the difficulty of spraying the lower surface of the leaves is greatly increased by the closeness with which beets are planted in the mounded-up beds. If the method of planting were modified so that the plants were grown in slightly separated rows, it would simplify the matter of spraying. It is evident that if sugar beets are to become a profitable crop in the Hawaiian Islands it will be necessary to spray them to prevent the ravages of this pest. For spraying large areas, such as fields of sugar beets, it is better to use a large geared or power sprayer. In some experiments which the author conducted on sugar beets in Colo- rado, against a somewhat similar species, the sugar-beet webworm (Loxostege sticticalis L.), ordinary barrel sprayers and geared sprayers, of 125 gallons capacity, were successfully used. With the nozzles arranged as in the accompanying illustration (Plate I, figs. 1, 2), it. is an easy matter to spray thoroughly the underside of the leaves, if a pressure of 80 to 120 pounds is maintained. DESCRIPTIONS OF THE EARLIER STAGES. By H. G. Dyar, Ph. D. The egg. — Uniformly elliptical, strongly flattened on the upper and lower sides, smooth, minutely granular; white (in alcohol). Size 0.6 by 0.4 by 0.25 mm. Laid singly on the underside of the leaf near a vein. Larva, stage 1. — Head rounded, not much higher than wide, slightly notched at vertex ; smooth, shining testaceous whitish, with four large, black, pigmented ocelli close together in a semicircle, setse rather coarse, pale, those next the ocelli darker. Width, about 0.25 mm. Body cylindrical, slender, uniform, whit- ish or colorless (in alcohol). Set* coarse, from small concolorous tubercles, i and ii nearly in line with some coarse skin spinules near them ; iv and v super- posed, approximate; vi wanting; vii of three setse at the leg base. Legs long, slender, normal. The intermediate stages are not complete in the material. In all the larva is whitish throughout, marked only with a subdorsal black speck on joints 2 and 3. Larva, last stage. — Head rounded, higher than wide, notched on vertex, clypeus high, reaching vertical notch ; whitish, with brown freckles on the vertices of the lobes, cut by a central space devoid of these spots; five pigmented ocelli in a semicircle and one colorless one behind. Width, 1.2 mm. Body cylindrical, slender, uniform, the segments irregularly annulate; abdominal feet slender, cylindrical, the plantae circularly expanded, the crochets in two-thirds of a circle, the open space on the outside; setse fine, from concolorous invisible 12 INSECTS AFFECTING VEGETABLES. tubercles, i and ii in line, iv and v approximate, superposed, iii and vi normal, vii of three separated setae; joint 2 with six setse on the shield in two rows, the shield concolorous; two seta? each for the prespiracular and subventral tubercles; joint 3 with iia and iib in line, iii separate, iv and v approximate, vi free. Color whitish, a long brown patch at the edge of the shield on joint 2 and over tubercles iia and iib on joint 3. Spiracles elliptical, those of joint 12 larger than the others. The cocoon. — The cocoon is composed of silk with fragments of extraneous substances attached to the outside. Elliptical in shape, simple. The pupa. — Of the obtected type; pale brown, the eyes dark. Cremaster square and flat, with a row of long, slender, terminal pale spines with hooked tips. Surface smooth, without sculpture. Size 10 by 2.5 mm. APPENDIX. Ey F. H. Chittenden, Sc. D. Owing to the fact that Mr. Marsh's report on the Hawaiian beet webworm (Hymenia fascialis Cram.) was completed at Rocky Ford, Colo., he had no facilities for looking up the literature on the species. Moreover, it was thought advisable, owing to the difficulty of describ- ing the earlier stages in alcohol, that a technical description be made by a specialist, hence this latter work was kindly furnished by Dr. Dyar. while the writer has compiled the description and synonymy of the species and outlined its distribution, history, and bibliography. In the preparation of the bibliography, Mr. Thomas H. Jones as- sisted, while the photograph of the moth was prepared by Mr. C. H. Popenoe, and the drawing of the immature stages by Mr. J. F. Strauss. Much has been written of this species in a technical way, but prac- tically nothing has been published of importance, to the writer's knowledge, in regard to the biology of the insect, or description of its earlier stages. Hence the notes which Mr. Marsh has furnished are of great value, especially as he treats the insect in detail from the standpoint of its occurrence and injuries in Hawaii, and has also per- formed valuable experiments in the line of remedial measures. It should be added that this species, since it occurs throughout the Gulf region west to California, is apt to be troublesome at any time. DESCRIPTION AND SYNONYMY. Hymenia fascialis was first described in the year 1782 hj Cramer. The following is the synonymy accorded by Dr. Dyar in his list of North American Lepidoptera, published in 1902. fascialis Cramer, Pap. Exot., iv, 236, 1782, syn. angustalis Fabricus, Mant. Ins., ii, 222, 1787. recurvalis Fabricus, Ent. Syst, iii, 2,237, 1794. diffascialis Hubner, Verz. bek. Schmett., 361, 1826. allrifascialis Boisduval, Faun. Ent. Mad., 119, 1834. THE HAWAIIAN BEET WEBWOEM. 13 The species has also been placed in the genera Zinckenia and Spoladea. The following is a somewhat free translation from Cramer's orig- inal description in French : Fig. O — Fascialis. — The white band and the spots on the black ground of this little moth, of which the two surfaces of the wings carry the same colors, are of a mother-of-pearl luster. The antennae are filiform, the feet very long and slender, similar to all those which belong properly to the so-called family Phal. [a?na~\ Pyralis. Monsieur M. Houttium has received it from Japan. On the same page, as throughout the work, a similar description is furnished in Holland Dutch. The reference to the illustration is Volume IV, of the same work, page 398, figure O. The synonymy which follows is in accordance with Moore : Phalcena recurvalis Fabricius, Syst. Ent., p. 407 (1775) ; Ent. Syst, iii, 2, p. 237 (1794). Zinckenia recurvalis Zeller, Lep. Micro. Caffr. Kongl. Yet. Akad. Handl., p. 55 (1853) ; Lederer, Pyral. Wien. Ent. Mon., vii, p. 437 (1863) ; Snellen, Tijd. voor Ent, 1872, p. 95 ; Meyrick, Tr. Ent. Soc. Loud., 1884, p. 308. Spoladea recurvalis Guenee, Delt. et Pyral., p. 225. pi. 8, fig. 5 (1854). Hymenia recurvalis Walker, Cat. Lep. Het. B. M.. xvii. p. 396 (1859). Phalena fascialis Cramer, Pap. Exot., iv, pi. 398, fig. o (1782). Stoll, id., v, pi. 36, fig. 13 (1791). Phalcena angustalis Fabricius, Mant. Ins., p. 309 (1787). Hymenia diffascialis Hiibner, Verz. bek. Schniett., 361 (1825-7). Hydrocampa albifascialis Boisduval, Faun. Ent. Madag. Lep., p. 119, pi. 16, fig. 1 (1834). fPhalama nigrella Linnaeus, Syst. Nat., Ed. 13, iii, App., p. 225. DESCRIPTION OF THE GENUS. The genus Hymenia is defined as follows : Forewing rather narrow, triangular; cell more than half the length; first subcostal at one-fifth before end of the cell, third bifid, fifth straight from end of cell ; discocellular slightly concave, radials from the ends ; middle median very close to end of cell, lower at nearly one-third; hindwing short, rather broad, apex convex, exterior margin convex in the middle ; cell two-fifths the length ; subcostals from end ; discocellular obliquely concave, radial from lower end ; two upper medians from end of cell, lower at one-third. Body moderately slen- der; labial palpi ascending, slightly curved, reaching level of the eyes, second joint laxly squamous, broadest at the base, third joint small, slender, pointed; maxillary palpi slender; antennae setaceous, basal joint nodular; legs slender, smooth, spurs long, hind spurs equal. (Moore). DESCRIPTION OF THE SPECIES. The species is described as follows : Dark vinaceous-brown ; in some lights olivescent greyish-brown ; forewing -with a short blackish-bordered white band from the costa before the apex, below and exterior to which are three small inwardly curved superposed spots. 14 INSECTS AFFECTING VEGETABLES. which approach a dentate transverse white band extending from upper end of the cell to the posterior margin, this band being continued across the hindwing to near anal angle. Cilia with an interrupted brown inner line, alternated with white on forewing, entirely white on hindwing, bands on abdomen white, collar, front of head, base of palpi, and legs yellowish ; tip of palpi and bands on fore- legs blackish. Expanse seven-tenths to nine-tenths inch. (Moore.) DISTRIBUTION. In Dr. Dyar's list the distribution accorded this species includes the United States, South America, southern Europe, South Africa, and Australia. There is also a record of this species occuring in India. Cramer's type was from Japan. Hampton states that its habitat comprises "Neotropical and Ethiopian regions"; Palaearctic Asia from Syria to Japan ; the whole oriential and Australian regions. In the United States National Museum this species is represented by specimens from Key West, Fla. (Evermann) ; Miami, Fla. (Barnes) ; Jamaica, Dallas County, Ala. (Trelease) ; and Port au Prince, Haiti. To make this list more complete we should add Cali- fornia and Hawaii, the islands of Madagascar, Bourbon (Reunion Id. ) , and Mauritius. From the above it will be noted that this species is evidently of tropical origin, that it has been well disseminated nearly around the world, but that it is still confined to tropical, semitropical, and tem- perate climates. In the United States it probably has a larger range than above indicated. It at least ranges through the entire Gulf region to California. HISTORY. As has previously been stated, the species was first described by Pierre Cramer (1), who figured and described the moth, the descrip- tion being in both French and Dutch, appearing in 1782. The type specimen was from Japan. In 1884—1887 Moore (2) furnished a technical description, with complete bibliography, which has been transcribed in previous pages. Following this, in 1900, Mr. Edward Barlow made mention of injuries by the larvae to Amaranthus man- gostanus, a pot herb in India, quoting Moore's synonymy and descrip- tion. In 1907 Mr. W. W. Froggatt (6) stated that this little moth was common about Sydney, Australia, and that the larvce were some- times destructive to salt-brush hedges. Two years later (1909) Mr. O. H. Sw^ezey (7) stated that the larva was fed on Euxolus, portu- laca, garden beet, coxcomb, other amarantaceous plants, and on chenopodiaceous weeds. The same year Messrs. Lefroy and How- lett (8) published a short note on this species, stating that the larva attacked cultivated amaranthus, beet root, maize, and " other garden plants." BIBLIOGRAPHY. 1. Cbamee, Pierre.— Papillons Exotiques, pt. IV, p. 236, pi. 398, fig. 0, 1782. Original description in French and Dutch. Colored figure of adult. Type from Japan. 2. Moore, F.— The Lepidcptera of Ceylon, vol. Ill, pp. 293, 294, 18S4-18S7. Technical description with complete bibliography. 3. Barlow, Edward. — Ind. Mus. Notes, vol. 4. no. 1, pp. 16 and 17, pi. 11, fig. 5, 1900. Mentioned as recurvaJis. Injurious to Amaranthus mangostanus L., a "pot herb" of India. Synonyms and description after Moore. Localities of specimens in Indian Museum. 4. Dyar, H. G.— Bui. 52. U. S. Nat. Mus., p. 373, 1902. Listed with synonymy and distribution. 5. Holland, W. J.— The Moth Book, p. 392, pi. 47, fig. 28, 1909. Mentioned as Zinckenia fasciaJis; synonymy: said to be found all over the tem- perate and subtropical regions of both hemispheres and to be common in southern portions of United States. 6. Froggatt, W. W.— Austr. Ins., p. 270, Sydney. 1907. " Common little moth about Sydney."' Larva3 sometimes destructive to salt-bush hedges. Mentioned as Zinekenia recurvaJis. 7. Swezet. O. H— Proc. Haw. Ent. Soc. vol. 2. no. 3, p. 136, 1909. Mentioned as recurvaJis. Said to feed on Euxolus portulaca, garden beet, cox- comb, other amarantaceous plants, and on chenopodiaceous weeds. S. Lefrot, H. M., and Howlett, F. M— Ind. Ins. Life, p. 516, 1909. Short note. Cultivated Amaranthus, beet-root, maize, and " other garden plants " mentioned as hosts. 9. Yiereck, H. L.— Proc. U. S. Nat. Mus., vol. 40. p. 1S9, 1911. Description of a parasite, Cremastus liymenice n. sp., reared from this species at Oahu, Hawaii. 10. Marsh. H. O.— Bien. Rept. Bd. Agr. and Forestry. Hawaii (1910). p. 157, 1911. Short note. Paris green mentioned as an effective remedy. 15 o U. S. D. A., B. E. Bui. 109, Part II. T. C. & S. P. I. I., November 11, 1911. PAPERS ON INSECTS AFFECTING VEGETABLES. THE SOUTHERN BEET WEBWORM. {Paehyzancla bipunctalis Fab.) By F. H. Chittexden, Sc. D., In Charge of Truck Crop and Stored Product Insect Investigations. INJURIOUS OCCURRENCES AND NOTES ON HABITS. On September 24, 1906, the Bureau of Entomology obtained from Mr. F. W. Roeding, Wichita Falls, Tex., the larvae, pupae, and adults of the pyralid moth Paehyzancla bipunctalis Fab., which had been found operating on foliage of table beets in that vicinity. One larva transformed to pupa On September 25, and the adult issued October 3, the pupal period thus having occupied eight days in an average tem- perature of about 70° F. From this lot imagos continued to issue until October 2, and a larva matured October 10 which would have produced an imago about October 30. During October, 1907, Mr. H. M. Russell observed larvae at Dade City, Fla., on beet tops from 6 to 8 inches high, " webbing up" the leaves with the edges of the leaves folded together or joining two or more leaves to make a nest in which to hide. From this conceal- ment they emerge and eat the leaf cells composing it, usually leaving the leaf skeletonized or very thin. In these nest-forming and leaf-eating habits the insect resembles the related Pyraustidee. Mr. E. B. Embry, located at Dade City, Fla., stated that the larvae of this species had injured the foliage of small beets so badly as to reduce his crop about 50 per cent. As late in the season as November 29, the web worm larvae were found in another locality at Dade City, some of which showed parasitism. In January, 1909, larvae were observed attacking beets at Boynton, Fla., and in March, beets at Miami, Fla. From web worm material obtained October 18, one pupated October 23, and the moth issued November 8. Another larva pupated November 6 and the adult issued on November 21, thus indicating a pupal period covering from 15 to 16 days, in the latitude of Washing- ton, D. C. In another case the pupal stage lasted from December 31 to January 22, or a total period of 23 days. The temperature at Washington was moderatelv cold. 17 18 PAPERS ON INSECTS AFFECTING VEGETABLES. This species was observed in 1908, by Mr. D. K. McMillan, at Brownsville, Tex., working in colonies on the foliage of pigweed (Amaranthus retrqflexus) , and on spiny amaranth (A. spinosus), the larvae webbing and folding the foliage in the previously described manner. The colonies in question came under observation on April 30, May 14, June 15, and November 5, 1908. Mr. McMillan also observed the larvae in large numbers during the spring of that year, working on " spinach" in the Kio Grande Valley and on beet foliage at Brownsville. On May 28, 1909, Messrs. McMillan and H. O. Marsh observed these larvae at Brownsville, Tex., embedded in the leaves of AmaraniJius retrqflexus. The larvae were not in abundance at that time, doubtless owing to the extensive parasitism in May and June of the preceding year (1908). This was the first observed appearance of the insect that year. During the same year this species twice came under the observa- tion of Mr. H. M. Russell, in the first instance at Boynton, Fla.; on January 27, 1909, when the larvae were found in great abundance on the foliage of table beets. They had nearly stripped an early plant- ing and were also abundant on a later planting. In many cases* the larvae were present on the underside of the leaves and had drawn the leaf into a fold, inside of which they were concealed. In other cases the larvae were concealed by the folding up of the leaf from the edge, while in further instances two beet leaves were fastened together in such a manner that the larvae were concealed between them. In feeding, the leaf substance is usually entirely eaten through to the surface, the leaf skeleton alone being left. The larvae void a very soft excrement which produces a filthy condition of the leaves. Later on, March 3, the larvae were found by Mr. Russell in fair abund- ance on beet tops at Cutler, Fla., and still later at Miami, Fla., on Amaranthus retrqflexus. Beginning with March, 1909, parasitic cocoons were seen on the leaves of beets, and early parasitism was indicated by the presence of parasitic cocoons on other food plants. Amaranth is abundant along the edges of many fields in southern Florida, and it is impossible to destroy it to a very great extent, as it grows luxuriantly on hun- dreds of acres of unclaimed lands. It costs from $15 to $75 an acre to clear hammock for planting. Perhaps, therefore, it is just as well to allow the amaranth to remain and to spray the weeds as a means of keeping tins pest in check. There is little doubt that unless the parasites continue their good work the species is likely to cause a serious outbreak at almost any time in the future. Of one lot of material received at Washington, D. C, the larvae of which were nearly mature, it was noticed that they began to "spin up" preparatory to pupation on May 7; the following day some of THE SOUTHERN BEET WEBWORM. 19 the larvae had pupated and by May 20 the adults had commenced to issue, thus giving a total period for the pupal stage of about 12 days. The moths were placed in a large cage with a growing beet and at the end of the week all had died. In other sendings of material the moths were observed to issue on May 25, June 3, and July 9. The length of the egg stage was not ascertained, but it may be safely stated to be approximately 6 or 7 days, in moderate or warm weather. From eggs laid on June 5 and 6 the adults developed July 3, giving a total life cycle of 28 days, or 4 weeks, in hob weather, which will be about the minimum for the species. Assuming that Fig. 3.— Southern beet webworm (Pachyzancla bipunctaUs): a, Moth; b, larva; c, lateral view of first proleg and abdominal segment of larva; d, pupa, with cremaster showing location of hooks at right. a, b, d, About three times natural size. (Original.) from 5 to 7 days is occupied by. the egg stage, and approximately the same number of days for the pupal period in hot weather, the larval period would be approximately from 14 to 18 days. At least four generations are indicated for this species, and it is possible that there are more, but there are no positive data on record on this point. DESCRIPTIVE. TTie moth. — The moth in color varies from buff to very pale yellow- ish gray. The wings are slender and the antennse long. In the pale forms the wings are nearly transparent, and the surface is rather iridescent purplish. The wing pattern of the pale individuals is faint, much more so than the illustration (fig. 3, a) would appear to indicate, 20 PAPERS ON INSECTS AFFECTING VEGETABLES. but is a little more definite in the dark forms. Near the anterior margin of the forewings there are three rather conspicuous black dots, one near the. middle and one each side. The underside of the wings is paler and somewhat similar to the upper. The eyes are dark brown, nearly black. The abdomen is darker than the wings, and there are two black spots on the anterior margin of the third abdominal segment. The legs are long and slender. The total length of the body is less than one-half inch (12 mm.) and the wing expanse is about 1 inch (22 to 26 mm.). The egg. — The egg is of irregular, short, oval outline, and consider- ably flattened upon the surface on which it is deposited. The color is pale yellowish, which looks green, owing to its semi transparence, permitting the color of the leaf to show through. The surface is finely reticulated, and under a high-power microscope is seen to be composed of minute, very irregular, moderately depressed areas, chiefly hexagonal and pentagonal in outline. The surface is rather strongly iridescent and glistens, presenting the appearance of a fish scale in miniature. Length, 0.6 mm.; width, 0.45 mm. Eggs obtained in confinement, May 26, were deposited singly on the underside of beet leaves. Mr. Marsh also observed the eggs on the underside of amaranth leaves at Brownsville, Tex., June 22, 1909. The larva. — The larva (fig. 3, b, c) is slender, cylindrical, and in the arrangement of the piliferous tubercles resembles Loxostege similalis Guen. and L. obliteralis Walk. The tubercles are not conspicuous in living specimens, but become prominent in preserved material. The color of the larva is dark, dirty green, with dark, mottled brown-and- black, or nearly black, head and thoracic plate, the latter widely sepa- rated at the middle. The dorsal piliferous tubercles are large and black, the two pairs being closely jointed. The remaining tubercles are large and infuscated, the dorsal ones transverse and arranged in two pairs, one pair on each segment. The tubercles of the last segment form a central plate, with a lateral one each side, in front of the larger anal plate. When boiled for preservation the larva becomes perfectly white, bringing into prominence the rings of tubercles which com- pletely encircle each segment. The length of the larva when full grown is about three-fourths of an inch (19-20 mm.), and the width 332 to J of an inch (2.5-3 mm). The pupa. — The pupa (fig. 3, d) is mahogany-brown, moderately slender, with the anterior extremity rounded, and the posterior pro- longed into a bill-shaped cremaster, armed at the end with four very fine hooks, one lateral and two apical pairs, their tips strongly recurved. The abdominal segments are without spines. The length is about two-fifths of an inch (10 mm.). The species is a pyralid and is placed in our lists next to Loxostege. It bears some resemblance to Loxostege similalis, but is considerably larger. THE SOUTHERN BEET WEBWORM. 21 DISTRIBUTION. This is without doubt a species of tropical origin and inclined to be cosmopolitan in any country suited to it elimatologieally. We have hi the National Museum collections material from Pernambuco, Bonito Province, Brazil, as well as from Georgia, Texas, Florida, and the District of Columbia. It is recorded also from the West Inches and South Africa. HISTORICAL AND BIOLOGICAL NOTES. This beet web worm was first described as "PTialsena 2-jmnctalis" in 1794.1 In the year 1880 the larva was observed feeding upon cauliflower at Savannah, Ga., where it was stated to be very destruc- tive. In consequence it was given the name of "Cauliflower botis." 2 It was also noticed that it fed on ragweed (Ambrosia), which is probably the original food plant, cauliflower being an acquired one, and perhaps not a food plant under normal conditions. The following year it was again noticed at Savannah, Ga., on pigweed, the larvae webbing the leaves together and destroying many plants. Nothing further seems to have been recorded of its habits. NATURAL ENEMIES. Pliorocera erecta Coq., a tachina fly, was reared from this species in September, 1906. This parasite has been reared from the related Loxostege similalis, at Victoria, Tex. AmorpJiota sp. near orgyise, an ichneumonid parasite, was reared January 15-29, 1908, from Pachyzancla oipunctatis , obtained from Dade City, Fla., in October and December of the preceding year. A single female 3 before the writer measures 8 mm. in length and is opaque black, with castaneous abdomen and middle and posterior legs. The fore legs, and the tibiae and tarsi on the middle pair of legs are light yellow, as is also the first joint of the antenna, the remainder of the antenna being black. Br aeon sp., a small blackish species of this genus,4 was reared from this host at Brownsville, Tex., "November 21, 1908. ASSOCIATED INSECTS. In addition to the parasitic natural enemies of this species which have been mentioned, some interesting species have been reared. Prominent among these is a moth of the same family and with some- what similar habits, known as the Hawaiian beet webworm 5 (Hy- menia [ZincTcenia] fascialis Cram.). It was reared by Mr. H. M. Rus- 1 Fabricius, Entomologia Systematica, vol. 3, pt. 2, p. 232, 1794. 2 Botis repetitalis Grote, n. sp., Comstock, J. H— Kept. U. S. Dept. Agr. for 1380, p. 270, 1881. 3 Chttn. Xo. 303°i. 4 Chttn. Xo. 1064"i. & Bui. 109, Part I, Bur. Ent., U. S. Dept. Agr., 1911. 22 PAPERS OX IXSECTS AFFECTING VEGETABLES. sell, at Cutler, Fla., March 23-29, 1909. It is interesting to remark that Mr. H. O. Marsh has found this species very destructive to sugar beets in Hawaii, and has made a special study of it for the Bureau of Entomology. An agromyzid fly was reared February 17, 1909, with this beet webworm from material received from Mr. H. M. Russell on beets and Amaranthus collected at Boynton, Fla. Pegomya ruficeps Stein, an anthomyiid fly, was reared under prac- tically the same conditions as the moth Hymenia fascialis Cram., above mentioned. REMEDIES. The remedies that have been advised for use against the garden webworm (Loxostege' similalis Guen.) should be found about equally effective against the present species. In any case their use is advised until more is learned of the habits of the southern beet webworm. These remedies are given below. Paris green. — Paris green is applied at the rate of 1 pound to from 75 to 100 gallons of water, or dry, distributed with a powder gun, as practiced in the South. The latter method, however, is inferior to spraying. Since the two species share common natural food plants (Amaranthus), the usual care should be exercised to avoid planting beets in fields which have grown up in this weed until after thorough fall or spring plowing. The experience which Mr. H. 0. Marsh has had with the related Hawaiian webworm conclusively shows the value of Paris green. He states, in brief, that a spray of Paris green at the rate of 2 pounds of the arsenical and whale-oil soap, 8 pounds in 100 gallons of water, proved absolutely effective and did no injury to the plants on which it was applied. The spray was applied to the underside of beet leaves.1 More complete information in regard to this is given in Part I of the present bulletin. It should be added that a mixture composed of nicotine sulphate, 1 fluid ounce, with whale-oil soap, 4 ounces, in 4 gallons of water, was used by Mr. Marsh against a number of noxious lepidopterous larvae, and although this formula was not tested on tne Hawaiian beet webworm, he believes that it would prove entirely effective. Dragging the log.— In the case of a bad attack of the garden web- worm in Oklahoma hi 1903, a satisfactory barrier to migration was employed, consisting of a dust furrow in which a log was dragged. This might be used in case the webworm under discussion should occur in great numbers before its presence is discovered-— something that is likely to happen, as in the case of species of related habits. i For some reason arsenate of lead applied to both sides of Amaranthus leaves was found ineffective and no explanation could be made of this, but the chemical was probably not pure. o U. S. D. A., B. E. Bui. 109, Part III. T. C. & S. P. I. I., April 5. 1912. PAPERS ON INSECTS AFFECTING VEGETABLES. THE IMPORTED CABBAGE WEBWORM. (Hellula undalis Fab.) By F. H. Chittenden, Sc. D., In Charge of Truck Crop and Stored Product Insect Investigations, and H. O. Marsh, Agent. INTRODUCTION, SPREAD, AND RAVAGES. Beginning with the year 1897 the imported cabbage webworm {Hellula undalis Fab.) has repeatedly come under observation as a pest in new States and Territories, namely, in Florida, Mississippi, North Carolina, Texas, California, and Hawaii. In 1907, Mr. H. M. Kussell observed attack to collarcls at Lake- land, Fla., in June and July, to collarcls at Orlando, Fla., in July, and at Dade City, Fla., to cabbage in December. The species has undoubtedly been in that State for many years, since it has been known for more than a decade from South Carolina to Georgia, but this is the first record of injurious occurrence there. In November, 1907, Pro?. K. I. Smith reported injury to cabbage at West Ealeigh, X. C. Whether this insect will be able to establish itself much farther north than the Carolinas is problematical. Our records show complete establishment throughout the Gulf States; in fact, the insect occupies a considerable portion of the same terri- tory as that permanently inhabited by the harlequin cabbage bug (Mnrgantia Mstrionica Hahn), save that the latter, having been introduced many years earlier, is better known and occurs farther northward. A review of the distribution of this species shows that it first came under notice as a pest in 1897. when it was destructive to cruci- fers about Augusta, Ga. Here it did great injury during that and the succeeding year. In after years it was observed in various other localities in Georgia, at Auburn, Ala., and at Charleston and Beech Island, S. C. Later it was noticed as a pest in Texas. The list, which will be furnished under the heading of distribution, simply includes the localities reported to this bureau and is doubtless 23 24 PAPERS ON INSECTS AFFECTING VEGETABLES. far from being complete. The mere occurrence of this insect at Los Angeles, Cal., was observed as early as 1891 or 1892, but nothing further was heard of the insect in the Pacific States until 1907, when it was reported by Messrs. Ball and Titus, working on sugar beets in that same region. In 1908 the species came under the observation of the junior author on several occasions in Orange County, Cal. In October it was found attacking horse-radish and cabbage at Santa Ana in the customary manner, namely, feeding in the heart, webbing the leaves, and eating- out the tissues. At Garden Grove, Cal., it was attacking cabbage and mustard. During June, 1908, Mr. D. K. McMillan observed this species on radish, cabbage, and kale. at Brownsville, Tex., the plants being con- siderably damaged. The larvae in most cases had destroyed the " buds " or had bored down into the center of the plants. They seemed to attack only the midrib of kale and most cabbage plants, feeding in a groove on the upper surface, which they cover with a web, varying this by eating a small cavity extending along the in- terior from one-fourth of an inch to an inch in some cases. Larvae were observed on rape at Mission, Hidalgo County, and at Santa Maria, Cameron County, Tex. At Brownsville they were found in November on mustard cultivated for table use. At this time many were found with tachina eggs placed in the usual location near the head. Turnip tops were also affected, the work on turnip and mus- tard being similar to that observed on rape and radish. The larvae concealed themselves along the midrib, boring down into it as well as along the groove, with a covering of silk under which they are fairly well protected. From finding the insect in many localities, in several cases not in destructive numbers, Mr. McMillan expressed the opinion that the species in southern Texas is evidently largely controlled by parasites and other natural enemies, as most individuals observed, even in June, were parasitized. It is probable that the species is well dis- tributed throughout nearly the entire State of Texas^ and, although held in check during most seasons by natural enemies, there is always the likelihood that at any time it may crop out as a serious pest. October IT, Mr. Charles M. Jones, Stallo, Miss., reported injury to turnip and collard. The larvae were not so active when the weather was cool and appeared to work at all times of the day. An entire crop of collards was destroyed. In Mississippi, also, Mr. M. M. High found larvae September 9, 1909, in large numbers on cabbage and turnip near Columbia, He described them as beginning work by first spinning a web in which to retreat. They then eat out the ends of young plants and check their growth, besides causing the death of some of them. They did much damage, cutting out the " buds " of young cabbage, in addi- THE IMPORTED CABBAGE WEB WORM. 25 lion to devouring the remaining leaflets and spinning their small but conspicuous webs over the plant. A grower here stated that the damage seemed greater that season than heretofore, and that he should have been marketing cabbage, but had none that had small heads, all having been destroyed by this larva. He had tried to poison the larvae with Paris green applied dry, but with little success. The webs prevent the poison in powdered form from reaching the caterpillar in its protected feeding quarters. The insect infests the turnips to about the same extent as cabbage, while it seems to be not quite so serious with turnips. September 16, 1909, the larvae did considerable damage to cabbage and turnips at Kosciusko, Miss. When first hatched they are diffi- cult to find, because of their habit of concealing themselves in the crotch of a stalk and turning the edges of the leaflet back, forming a domicile into which they retreat when not feeding. September 24, this pest was seen in large numbers on turnips at Crystal Springs, Miss. Many had already transformed to adult, as many cocoons were found containing empty pupal cases. This pest had destroyed about 16 per cent of the turnips upon the plat and many dead leaflets were found among the remaining green ones, due to its ravages. Hundreds of moths were flying over the patch, alighting upon turnips and upon the ground. It was thought that the insect was destined to do greater damage before the season was over, as many larvae were still spinning their webs and devouring the leaves. The part of the plat most seriously affected by the pest was not nearly so well fertilized as the remaining portion. The portion where most damage was done was upon high dry land, while the remaining portion was upon damp rich soil. This same species was observed cutting buds from late cabbage at Columbus, Eidgeland, Starkville, and Gulf port, Miss. Mr. High wrote: The moth undoubtedly deposits her eggs near the "bud," where they hatch, the young larvse devouring the bud, spinning webs, tying the larger leaves together, one to three larvae going to each leaflet, curling the edge of the leaf and forming an individual web, and, later, spinning a cocoon to transform into the pupal stage. The larvae come out of these webs to feed and then retreat when their hunger has been satisfied. This is one of the most serious pests of the truck grower about Crystal Springs, Miss. It is evident that this remark may apply to practically the entire State of Mississippi, and that similar conditions obtain in Georgia and South Carolina. February 3; 1909, Dr. W. E. Hinds, entomologist to the Alabama Experiment Station, Auburn, Ala., wrote that he had received this species from Phoenix City and Montgomery, besides Auburn. October 2, Mr. High reported that he had again found this pest at Gulfport, Miss., both upon late cabbage and turnips. Injury was 26 PAPEES ON IXSECTS AFFECTING VEGETABLES. more serious on young cabbage, because the " buds " were being de- voured and small webs filled with excrement were left in their stead. There was only a small plat of cabbage where, on the other hand, there were acres of turnips. The webs were distributed also over the turnips, some of them being empty, the larva having transformed to the moth. This pest was doing great damage to the two truck crops. Some other pests were associated with it and were doing some injury, such as the flea-beetle {PhyUotreta Mpustulata Fab.) and the cabbage looper (Autographa brassicce Riley). During the fall of 1909 the late F. C. Pratt reported this webworm as a pest to cruciferous crops at Sabinal, Tex. About the middle of January, 1910, the junior author visited Sabinal and in company with Mr. Pratt examined the gardens where injury had occurred. The characteristic work of the larva was observed on radish and cabbage, which remained as crop remnants, but none of the insects was found. Mr. Pratt said he had taken an adult, out of doors, late in Xovember and expressed the opinion that the insect might winter in the adult condition in that locality. October 22 the larva was observed in large numbers at Columbus, Miss., upon cabbage, turnips, and collards grown by Mr. J. E. Slaughter. The larvae bore into the stems of the cabbage and tur- nips for some little distance or eat out small crevices in the edges of the stems, enough to bury their bodies, and then, spinning a cocoon, they transform into pupae. Xovember 2, 1909, the larva was found by Mr. M. M. High in large numbers at Starkville, Miss., upon turnips. The larva was observed in the crotch of every other plant, boring and hiding from the light. From one to three were found in the " buds." Fully 50 per cent of the turnip crop under consideration had the buds de- stroyed by this imported webworm. The plants attacked had small roots and looked stunted or checked in their growth. This insect seems to do the greater damage to cabbage and turnips, although injury to collards is by no means slight, especially while the latter are young. The larva seems to prefer turnips in the row to those sown broadcast. There was not a plant, either cabbage or turnip, but that contained from two to many of these larvae. December 3, 1909, Mr. High found webworms of this species in large numbers in the crotch and stems of turnips at Hattiesburg, Miss., where the}7 concealed themselves beneath their webs, destroy- ing the most vital portion of the plant. One grower stated that this insect was a perfect nuisance to older plants and a menace to young ones. He said : The Utile striped worm enters the bud of both cabbage and turnip when the plants are quite young and devours them, thus forcing the plant to grow a new bud and start or begin new growth — my first crop of cabbage in the spring being almost totally destroyed from the work of this striped worm. THE IMPOKTED CABBAGE WEBWOKM. 27 The cabbage plat now appears to be unmolested by this larva, while nearly every turnip in the plat adjoining cabbage has one or more of the larvae some- where near the base of the stems or leaves* A few mature larvae were found at Brownsville, Tex., November 5, 1910, boring in steins of mustard and crowns of young cabbage plants. Evidence of past injury was common and indicated that the larvae were more numerous in early October. Several cabbage grow- ers stated that worms, which from their description were evidently this species, caused considerable damage in seed beds. One grower lost fully 50 per cent of his plants^ which had the bud destroyed and were worthless for planting. Turnip, mdish, and mustard plants in the earlier stages were gen- erally attacked and stunted or caused to grow misshapen, and in some cases were entirely destroyed, the larvae boring down into the base of the crown and upward into the leaf stems after eating out the crown. Several larvae attacked a plant simultaneously. At a meeting of the truck growers on the Indiana Canal, 5 miles east of Brownsville, Tex., held November 28, 1910, nearly everyone reported more or less damage to seed beds of cabbage in October. Several had tried dusting with Paris green and lime, but evidently after the injury began to be noticed the larvae could not be reached in their burrows under the protection of the web. Very few sprayers were -in use among the farmers, who were mostly newcomers in this section. At Henry Keller's at least 25 per cent of his seed beds were ruined, and in small areas about 75 per cent had the bud eaten while the plants were small. More than 25 per cent of his young cauli- flowers set in the field were injured, and in many cases would not make perfect heads. There were a few small larvae found at this place and several adults were observed. Particulars in regard to earlier occurrences are given by the senior writer in the following bulletins of the Bureau of Entomology : No. 19 (pp. 51-57), No. 23 (pp. 53-61), and No. 33 (pp. 18, 19)7 DESCRIPTION AND LIFE-HISTORY NOTES. THE MOTH. The moth is illustrated at a of figure 1. It is gray in color, with the forewings marked and mottled, as shown. The wing expanse is about five-eighths of an inch (18 to 21 mm.). The following tech- nical description is copied from Dr. Hulst'S paper (1) : Palpi, head, thorax, and abdomen fuscous; forewings broken fuscous and fuscous cinereous; the basal space with a black spot medially, two white lines across the wings, the first extra basal edged with dark fuscous, the outer after the typical Botis pattern ; a dark-brown spot annulate with white at reniform ; a dark-brown subtriangular apical patch, and a subterminal white line ; marginal line black, broken ; hind wings, even fuscous ; beneath, lighter, lines obsolete, reniform indistinct. 20639°— Bull. 109—12 2 28 PAPERS ON INSECTS AFFECTING VEGETABLES. The following synonymy is recognized: Hellula undalis Fab., Ent. Syst, vol. 3, 2, p. 226; Herrich-Schaffer, Eur. Schmett., vol. 4, pi. 8, f. 54. Scoparia alconalis Walker, Catalogue, vol. 19, p. 827. Leucinocles exemptalis Walker, Catalogue, vol. 34, p. 1313. Botys rogatalis Hulst, Trans, Airier. Ent. Soc, vol. 13, p. 149. The wing venation, head, and antenna arc shown in figure 5. THE EGG AND OVIPOSITION. A pair of moths newly reared was placed in a vial July 24, and next morning the female was found to have deposited singly, doubly, and in masses of from 3 or 4 to 20, a total of 235 eggs. The following day 24 were laid; on the 27th, 37 were found, or 296 in all. After- wards the moth died, hav- ing laid no more. A few eggs were found upon dis- section, making the prob- able number usually depos- ited between 300 and 350. Most of the moths die in confinement within a week. The egg. — The egg is of suffi- Fig. 4. — The imported cabbage webworm (Hellula undalis) : a. Moth; 7), Iarra. lateral view; c, larva, dorsal view ; d, pupa All three times natural size. (From Chittenden.) ciently large size, about four one-hundredths of an inch in length, as to be readily discern- ible to the naked eye. It is of oval form and rather variable in contour, being usually more or less flattened upon the surface of deposit, and there is often a distinct nipple at one extremity. Its greatest width is about three-fifths its length. The color when first laid is light gray, and under a strong hand lens the surface appears to be rugose and strongly iridescent. Under a higher power the surface is found to be made up of depressed irregular areas, mostly hexagonal and penta- gonal in outline. Length, about 0.5 mm. ; greatest width, 0.3 to 0.35 mm. A day after deposition the eggs begin to take on a pinkish hue, due to light reddish spots below the surface. On the second day the embryo can be detected, the head showing as a blackish dot near one end and on the lower surface of the eg_ side of attachment. Experiments conducted in the latter days of July, in a temperature officially rated by the Weather Bureau of this department as mod- Fig. 5. — The imported cabbage webworm : Wing venation, head, and antenna. All en- larged. (After Hamp- son.) or the THE IMPORTED CABBAGE WEB WORM. 29 erate (indoor 80° to 84° F.), showed that the eggs hatched three days after deposition, a rather remarkably short period for the eggs of a moth with a wing expanse of nearly three-fourths of an inch. THE NEWLY HATCHED LARVA. The larva when just hatched measures about a millimeter in length and about a twelfth that in diameter across the abdomen. The head, as is usual with young larvae, is prominent, wider than the body, and dusky in color. The thoracic plate is also dusky and of somewhat similar subcrescentic form to the more mature stage. The body is very pale yellowish gray, nearly white, and the surface is moderately clothed with long, fine hairs. Very soon after hatching the larva shows the characteristic striae of the more mature form. Thus larvae 2 mm. in length are so little different in general appearance from the full-grown ones as to be readily recognized as of the same species. THE FULL-GROWN LARVA. The full-grown larva, shown at h and c of figure 4, measures a little upward of half an inch in length, being about six times as long as wide. The form is subcylindrical, tapering toward each extremity, widest near the middle — the third, fourth, and fifth abdominal segments being nearly equal. The general color is dull opaque grayish-yellow or yellowish-gray, striped with broad, somewhat irregular, brownish-purple, longitudinal bands, which extend from the second thoracic to the terminal or anal segment. These are bright and conspicuous on the dorsal and more feebly indicated on the ventral surface. The dorsal stripes are five — a moderately wide medial one. a broader medio- lateral on each side, and a dorso-lateral one, of about equal width with the median one, also on each side. On each side below are two lateral lines, faint, and interrupted toward the ends of each segment ; a similar ventro-lateral line ; and a much fainter interrupted median line. The head is black and shining, the V-mark well indicated, the cervical or thoracic shield is shining, light, somewhat purplish-gray, and is rather variably marked with brown, which forms, each side of the median stripe of the second thoracic segment, two irregular longitudinal dark brown patches, darkest and widest toward the posterior margin. On each side above the spiracle of that joint is a shorter dark patch. Near this there are sometimes two or three small dark rounded spots. The spiracle of this segment is dark brown, the remainder being concolorous with the body. The thoracic legs are more or less infuscated, and the prolegs are nearly concolorous with the venter. The entire surface of the body is sparsely covered with moderately long yellow and light brown hairs, proceeding from small and shining piliferous tubercles. The anal shield bears from 10 to 12 round purplish spots, the most posterior one the largest and standing alone, the remainder forming a subcrescentic pattern. The length when in natural position at rest is about 13 mm. and when extended 15 mm., the width being a trifle more than 2 mm. at the widest part. THE PUPA. The pupa is moderately shining, light yellowish brown in color and the sur- face is covered with a light pruinose bloom. The eyes are dark brown, varying 30 PAPEES ON INSECTS AFFECTING VEGETABLES. to black, and the dorsum is marked by a median stripe. The contracted ante- penultimate segment is noticeable. The anal segment terminates in two pairs of straight brown hairs. It is of rather robust cylindrical form, measuring about three-tenths of an inch (7.5 mm.) in length and one-twelfth (2 mm.) in width. The somewhat peculiar outline of the abdominal segments is shown at d of figure 4. Transformation to pupa and thence to imago takes place in a rather compact cocoon composed of webbed-up grains of earth, which the larvae form after burrowing into the soil. Those before the writer measure about three-eighths of an inch (9 mm.) long and a little less than half that in width. The notes which appear above, on the life history of the species, were made by the senior writer at Washington, D. C, where the temperature and other conditions are not materially different from those of the Eastern Gulf States. DISTRIBUTION. In previous articles it wTas stated that this species would probably not spread beyond certain natural boundaries, i. e., not much above the Lower Austral life zone. Thus far this prediction has been verified. The following is the known distribution as recorded in this branch of the bureau : West Raleigh, N. C. ; Charleston and Beech Island, S. C. ; Auburn, Phoenix City, and Montgomery, Ala. ; Augusta, Way- cross, Tifton, Athens, Griffin, Montreal, Albany, Marshallville, Ma- con, Fort Valley, Meansville, and Leesburg, Ga. ; Lakeland, Dade City, and Orlando, Fla. ; Stallo, Columbia, Kosciusko, Crystal Springs, Columbus, Ridgeland, Starkville, Gulfport, and Hatties- burg, Miss. ; Corpus Christi, Brownsville, Beeville, Mission, Santa Maria, and Sabinal, Tex.; Los Angeles, Orange County, Santa Ana, and Garden Grove, Cal. ; and Honolulu and Wahiawa, Hawaiian Islands. The foreign localities need not be repeated. FOOD PLANTS. The first record of injury by this species was to cabbage, turnips, and beets. October 14, 1897, Mr. N. L. Willett, a reliable corre- spondent of this department, estimated that the cost to the growler of these plants and collards in the county of Richmond, Ga., alone would amount to $15,000 to $20,000 during that year, while Mr. W. M. Scott, at that time State entomologist of Georgia, estimated, November 26, 1897, a loss to that county of $50,000. Besides cabbage, turnips and beets, collards, cauliflower, kale, ruta- baga, radish, kohl-rabi, mustard, rape, horse-radish, and some other THE IMPORTED CABBAGE WEBWOKM. 31 cultivated plants, such as "Japanese radish," are subject to attack and injury. Among weeds and wild food plants are the common shepherd's purse {Bursa [Capsella] bursa- past 'oris) and "pussley" or "cutter's grass," otherwise purslane (Portulaca oleracea), NATURAL ENEMIES. Natural enemies of cruciferous insect pests are of great value in keeping their hosts in check, and some dependence must be placed upon these agencies in restraining the undue multiplication of this webworm. Indeed, there is evidence that they do hold it in check in many regions, al- though they have not prevented its natural spread. In spite of the short time that we have known of its occur- rence in this country as a pest — since about 1899 — we are already certain that at least five natural enemies, and probably more, are at work in deci- mating its numbers. Exorista pyste Walk, (fig. 6), a tachina fly, has been repeatedly reared from the cater- pillar of Hellula undalis from July 27 to as late as October 27. Limnerium tibiator Cress., a very abundant parasite reared with this species, is an ichneumonid. It was reared from the latter part of October until the last week of December. It has not been posi- tively ascertained to prey upon this larva, as it is a well-known enemy of the diamond-backed moth (Plutella cruciferarum Curt.), which was also present in smaller numbers, but as it is also known to attack the cabbage looper (Autographa brassicm Eiley) and Mineola indi- ginella, it seems probable that it is in reality an enemy of this web- worm. Plagiprospherysa sp., a tachinid fly parasite, was reared June 12 an