iii r-iii: UNITED STATES DEPARTMENT OF AGRICULTURE Ik BULLETIN No. 599 J^-'^^u Contribution from Bureau of Entomology L. O. HOWARD, Chief Washington, D. C. PROFESSIONAL PAPER March 16, 1918 THE STRIPED PEACH WORM/ By H. G. Jngekson, Scientific Assistant, Deciduous Fruit Insect Investigations. CONTENTS. Introduction 1 History 2 Synonymy 2 Food plants 3 Feeding habits of tlie larva 3 Character of injury on peach 3 Character of injury on sand cherry 3 Description 4 The adult 4 The egg 4 Description— Continued. The larva 4 The pupa 5 The cocoon 5 Seasonal history and habits 5 Summary of seasonal-history studies 11 Parasites 12 Remedial measures 13 Literature cited 14 INTRODUCTION. The striped peach worm {Gelechia confuselTa Cham.), although described in 1875, has received little notice as an economic species. The larvffi feed in conspicuous webs on the foliage of the peach and on sand cherry {Primus pumila) in smaller but more compact webs. While at present this insect is not a major pest on peach, the larvae have been observed feeding on sand cherry in such numbers as to web nearly every terminal, partially defoliating the host plant, and this shows the latent possibility of extensive injury to peach or- chards. Under the direction of Dr. A. L. Quaintance, Entomologist in Charge of Deciduous Fruit Insect Investigations, the writer studied the biology and habits of tlie insect during the seasons of 1915 and 1916. The biological data secured, together with descriptions of all the stages and suggestions for control, are recorded in this paper. ^ The writer is indebted to the following members of the Bureau of Entomology staff : To E. H. Siegler for the photograph used in Plate I, figure 1 ; to H. K. Plank for Plate II, figure 1, and Plate III, figures 1, 2, and 3 ; to J. H. Paine for Plate II, figures 2 and 3, and to F. L. Simanton for determining the place of oviposition on sand cherry and for conducting the. spraying work in connection with the remedial measures. 11918°— 18 2 BULLETIN 599, U. S. DEPARTMENT OF AGRICULTURE, The life-history studies were started at Benton Harbor, Mich., in 1915 and completed in 1916. Adults were reared separately from larva? collected on the two host plants and were identified as Gelechia confusella, by Mr. August Busck, of the Bureau of Entomology. HISTORY. The adult of Gelechia confusella was first described by Chambers (1)' in 1875, but with no mention of the source of his material. Pettit (4), under the heading "A new peach worm," writes as follows : A number of worms working in peach leaves were received from Mr. T. D. Atkinson, of Holland, Mich., on September 17. They were lepidopterous larvae and were said to be very troublesome. The same species was received on July 3, 1899, from Monroe, Mich. One or two complaints were made from other places, though no specimens were sent. These are apparently the only published accounts of the occurrence of this insect. SYNONYMY. In 1899 Pettit (4) described the larva of this insect and figured the larva and pupa, designating them "Peach leaf-binder, Depres- saria persicaeella Murt." In the same publication (5) the adult is described as Depressaria persicaeella by Miss Mary E. Murtfeldt, of Kirkwood, Mo., from material sent her by Mr. Pettit. Miss Murt- feldt (6) changes Depressaria persicaeella Murt., to Gelechia. Dyar (7) lists Gelechia confusella Cham., with persicaeella Murt. as a synonym. Busck (8) lists Gelechia confusella Cham, with synonyms Depressaria persicaeella Murt. and Gelechia persicaeella Murt., and makes the following note: Cotypes of Miss Murtfeldt's species are in the United States National Mu- seum imder type No. 4697. The species is very close to the foregoing, and I have no doubt is the same as Chambers's Gelechia confusella, the type of which is lost but the description of which tallies in every detail with the peach feeder. In 1904 Pettit (9), under the name "The striped peach-worm ( Gelechia confusella) ," copied part of his former description and re- produced the figures of the larva and pupa of 1899, designating them as the " striped peach-worm." The synonymy stands : Gelechia confusella Cham., 1875. Depressaria persicaeella Murt.. 1890. Gelechia, persicaeella Murt., 1900. The writer has accepted the name " striped peach Avorm," as it seems to distinguish this insect from all other peach feeders and briefly describes the larva, which is the only stage commonly seen. 1 Reference is made by number to " Literature cited," p. 14. D. of D,- APi^ 15 19J8 THE STRIPED PEACH WORM. FOOD PLANTS. Previously published notes have recorded G. confusella as feed- ing only on peach foliage. During July, 1915, the writer observed a Avebbed condition on sand cherry {Primus puTnila) (PL IV) which resembled somewhat the injury already noted on peach (PI. I), though the webs were more tightly bound and less silk was ob- servable. The injury was so extensive and uniform over a sand- cherry thicket of about 15 acres in extent at this place near St. Joseph, Mich., that it seems probable that this is the native host plant of the insect. FEEDING HABITS OF THE LARVA. The larva feed either singly or gregariously on both host plants, and, though not voracious feeders, by their well-developed web- bing habit include in their webs much foliage that is not used as food. The larvae begin webbing directly after hatching, even before they feed, and usually spin the first thin white web on the underside of the leaves next to the midrib. They begin feeding next to the midribs of the leaves, first eating small irregTilar holes through the parenchyma and later skeletonizing either or both leaf surfaces. CHARACTER OF INJURY ON PEACH. The injury to the peach is caused by the feeding of the larvse on the foliage. The webs spun by the larvae are loose, with considerable silk showing, and are often very conspicuous. The leaves soon be- come dry and cease to function, when included in the webs. CHARACTER OF INJURY ON SAND CHERRY. The webs on the sand cherry are small and compact, with only a little silk showing, but in the fall the infested terminals and branches become prematurely brown and conspicuous. Feeding is confined to the foliage, and, although in rare instances the webs are constructed about fruit, in no cases have larvae been observed to feed on the fruit. Larvae of varying sizes are found in the same webs, indicat- ing the probability of repeated oviposition in the same terminal. From 2 to 12 larva? are usually found in the webs on the separate terminals, although the number is sometimes as high as 30. In most cases observed when there was only one web on a branch it was located at the terminal, but when more than one was present the webs started from the base as well as from the terminal. As the larvae enlarge the webs, they extend them along the branches, gradu- ally including more and more foliage. 4 BULLETIN" 599, U. S. DEPARTMENT OF AGEICULTURE. DESCRIPTION. THE ADULT. (PI. Ill, fig. 3.) Because of its completeness the description of the adult is copied from Murtfeldt: Antennae dark fuscous, indistinctly pectinate and banded on the under side witli pale buff. Palpi long, exceeding the vertex. Basal joint short, pale ; sec- ond joint one-third longer than apical. Bitish quite dense, distinctly divided, dark fuscous overlaid with cream-coloured scales, palest on inner side. Apical joint dark, very slender, with extreme tip cream white, most conspicuously so in $. Tongue long, sparsely scaled. Vertex dark brown. Face cream white. Thorax and teguUe purplish-brown. Fore wings almost black, with rich purplish gloss, and sparsely sprinkled with white scales. On the costa back of the apex is a small, irregularly triangular, cream white spot, and a few scattered scales of the same colour form an obscure outer border. In the cell near its upper mar- gin are two somewhat indefinite, cream-coloured dots in line, with a third one below and slightly back of the one nearest the base. Cilia fuscous, shading outward to gray. Lower wings shining silky, cinereous, almost silvery. Abdo- men pale brown, terminal segment banded with buff at posterior margin. Lat- eral tufts buff, inconspicuous; anal tuft reddish-brown. Under surface spec- kled with brown and cream. Legs brown, annulate with cream white at the joints and middle of the tibiae. Alar expanse from 16 to 17 mm. THE EGG. (PI. II, fig. 3.) The egg is bluntly elliptical, somewhat flattened at the smaller attached end ; length, 0.57 mm. ; greatest width, 0.42 mm. The color is clear white when newly deposited, changing within 24 hours to a creamy yellow, the surface smooth and shiny without markings. About 24 hours before hatching the eggs change to a pearl gray color. THE LARVA. (PI. II, fig. 1.) The newly hatched larva is about 1.5 mm. in length and is yellow- ish white in color, with, head and thoracic shield fuscous. The reddish brown stripes are discernible after about 9 days and as they develop they give color to the larva. A detailed description of the full-grown [arva is copied from Pettit : The larva, when full grown, is three-eighths of an inch in length and quite slender. Its color is dirty yellowish- white with back and sides marked by six reddish-brown longitudinal stripes all of which extend the entire length from the thoracic shield to the caudal extremity except the pair on the dorsum which unite on the last segment and terminate there. Last segment bordered caudally with fuscous and base of anal pro-legs colored the same. Venter marked along the middle with a stripe like those on dorsum and sides, THE STRIPED PEACH WORM. 5 which ax'e about equidistant from each other and of about the same width as the spaces between them, color reddisli-brown. Some of the spaces (yellow- ish-white) have dark points in them. Head and thoracic shield yellowish- brown, feet fuscous and dirty yellow. Four pairs of pro-legs beside anal pair which are of the same color as the ground color of the body. Base of anal pair black. Mature larvse (PI. II, fig. 1) were found to vary from three- eighths to five-eighths inch in length, and in color to vary from yellowish white with poorly defined stripes to a clear white with vivid venetian-red stripes. There is an anteriorly directed semi- circular black patch over each ocellar area. THE PUPA. (PI. Ill, fig. 1.) The pupa is unusually broad across the thoracic region, slightly flattened dorso-ventrally and quite variable in size. The average di- mensions of 10 were found to be 6.3 mm. by 2.6 mm. When newly formed, the pupa is a light brown, changing later to a dark brown, the head, thorax, and ventral region obtaining a much darker color than the other regions. The wing pads are long, extending to cover all but the 3 posterior segments of the abdomen. THE COCOON. (PI. Ill, flg. 2.) This species differs from many of the genus in that it pupates nor- mally in the soil. The larva enters the soil to a depth of about one- half inch and spins a white silken cocoon, which it incloses in fine soil particles and to the outside attaches coarser particles. Within this cocoon the larva pupates. The average size of 38 cocoons meas- ured was 9.3 mm. in length by 4.4 mm. at the greatest width, slightly flattened to conform to the pupa3 and usually distinctly curved. SEASONAL HISTORY AND HABITS. The following seasonal-history records were started at Benton Harbor, Mich., during the season of 1915 and were completed in 1916, in open-air insectaries in which glass battery jars were used as rear- ing cages. In all cases peach foliage was used as food for the larvae. There is one full brood and a partial second brood. The rearing studies began with the collection of a quantity of larvae September 3, 1914. These overwintered, and the moths which emerged were used for part of the 1915 records. The rearing ma- terial for 1916 was that kept from the season of 1915, together with moths emerging from pupae collected in May, 1916. 6 BULLETIN 599, U. S. DEPARTMENT OF AGRICULTURE. EMERGENCE OF SPRING BROOD OF MOTHS, 1916. The earliest emergence of moths took phice on May 22 and be- ginning on June 5 was quite regular until July 14, with the maxi- mum emergence on June 29. Table I. — Emergence of spring Jjrood of moths of the striped peach worm in 1916. Date of observation. Number of moths. Date of obseryation. Number of moths. Date of observation. Number of moths. Date of observation. Number of moths. May 22 May 30 June 5 June 6 June 8 June 10 June 11 1 2 1 4 5 3 June 13 Jime 15 June 17 June 18 June 21 June 23 June 25 12 30 24 21 56 43 17 June 29 July 2 July 4 Julys Julv7 July 10 July 12 60 32 14 3 18 4 2 July 13 July 14 Total... 3 3 364 OVIPOSITION OF SPRING BROOD OP MOTHS. * As the moths emerged they were placed in jars with peach foliage and fruit. The moths oviposited freely in confinement whenever fruit was supplied in the oviposition jars. The eggs were deposited both on the fruit (PI. II, fig. 2) and under the scales surrounding the attachment of the peach to the stem. In a single instance one egg was found in the axil of a peach leaf. On the sand cherry the eggs were found under the bud scales at the base of the current season's growth and in the axils of the leaves as indicated by the circles shown in Plate IV, figure 1, a. The occurrence of the eggs on the peach under orchard conditions was not noted. From Table III it will be seen that in 1915 eggs were being deposited in the jars from June 2 until June 26. LENGTH OF LIFE OF MOTHS OF SPRING BROOD. The length of life of 20 adults which were provided with a weak solution of clarified honey for food is shown in Table II. Table II.- -Lcngih of life of 20 moths of the spring hroocl of the striped peach tvorm, 1916. Number of moths. Days of life. Number of moths. Days of life. 1 5 5 4 4 6 9 12 3 1 1 14 16 28 20 Maxin-um length of life days. . 28 Minimum length of life do 4 Average length of life do 10. 6 THE STRIPED PEACH WORM. 7 The average length of life of the adults is seen to be 10.6 days. From observations made in 1915, however, one adult was found to live 31 days, and eight moths emerging previous to May 24 were alive a month later.. These moths were not supplied with food. HABITS OF THE MOTHS. The adults are not often seen in the field because of their small size and inconspicuous coloring. They are difficult to follow when seen because of their habit of short irregular flights and their re- semblance when at rest to the color of the twigs of the host plant. The characteristic resting position is shown in Plate III, figure 3, from a photograph of a live specimen. One pair of adults was ob- served in copulation in a rearing cage on June 21, 1916, at 10.30 a. m. The heads of the male and female were in opposite directions and no parts were in contact except the genital organs. Both moths remained quiet during copulation. FIRST BROOD. Incubation. In Table III the incubation period for the eggs deposited each day is shown. It w^ill be seen that there was a variation of from 10 to 19 days in the incubation period, and even with eggs deposited the same day on the same fruit and thus subjected to the same external conditions there was a variation of five days. The average length of the incubation period was 13.18 days. Table III.- -Inciihation period of first-brood eggs of the striped peach worm at Benton Harbor, Mich., 1915. Date of oviposi- tion. Number of eggs depos- ited. Date of batching. Number of larvae. Egg stage. Date of oviposi- tion. Number of eggs depos- ited. Date of hatching. Number of larvee. Egg stage. June 2. . . June 3. . . Junes... June 6... Jime 10. . 11 6 4 28 2 20 3 Jmie 15 . (June 16.. {June 19.. (June 20.. Jmie21.. fjime20.. 1 June 23.. ) June 24.. (June 25.. Jime23.. Jime26.. June 27.. 11 1 2 1 3 23 1 3 1 2 20 2 Days. 13 13 14 15 16 14 17 18 19 13 14 15 June 16. . June 18.. June 20.. June 20.. Total . . 6 29 4 5 (Jime26.. {Jime27.. 1 June 28.. Jmie28.. 1 June 29.. jJvmeSO.. (Julyl... June 30.. July?... 2 2 1 10 13- 5 1 2 1 Days. 10 11 12 10 11 12 13 10 11 118 107 June 12.. Maximum egg stage days.. 19 Minimum egg stage do 10 Average egg stage do 13. 18 BULLETIN 599, U. S. DEPARTMENT OF AGEICULTUKE. Feeding Period of Fiest-Bkood Larv^. The feeding period of the larvae in the rearing cages in 1915 ex- tended from June 15 to August 5. In 1916, larvae were feeding from June 22 until August 1 as shown in Tables IV and V. The longest feeding period recorded was 48 days, the shortest 22 days, and the average 29.6 days for transforming larvae, and 34.2 days for over- wintering larva?. On July 28, 1915, the writer came upon the in- jury on sand cherry. The infestation was at its height and prac- tically all the insects in the larva stage. By August 11 about one- half the larvae had left the webs and newly formed pupae were to be found in the soil. Observations made on September 14 showed that from 95 to 98 per cent of the larvae had left the webs. Table IV. — Length of feeding period of transforming first-brood larvce of the striped peach icorm, 1916. Date of hatching. Date of ofcocoon- ing. Number of COCOOILS. Days of feeding. Date of hatching. Date of cocoon- Ing. Number of cocoons. Days of feeding. June 22 July 20 July 22 July 24 July 26 July 27 July 28 1 3 1 1 2 1 28 30 32 34 35 36 July 17 July 20 July 26 2 22 Do Do. 25 Do Do 31 Do Total . . . Do 14 Do Maximum length of feeding period days. . 36 Minimum length of feeding period do. . 22 Average length of feeding period do. . 29. 6 Table V. — Length of feeding period of wintering first-J)rood larvce of the striped peach tvorm, 1916. Date of hatching. Date of cocnon- mg. Number of cocoons. Days of feeding. Date of hatching. Date of cocoon- ing. Number of cocdons. Days of feeding. June 22 July 20 July 23 July 24 July 27 July 28 July 31 July 30 Aug. 8 2 1 2 1 4 3 2 1 28 31 32 35 36 39 38 47 June 22 Aug. 9 July 17 July 26 July 31 Aug. 1 1 1 3 1 1 48 Do. . June 25 22 Do Do 31 Do July 5 26 Do Do 27 Do Total.. Do 23 Do Maximum length of feeding period days.. 48 Minimum length of feeding period do . . 22 Average length of feeding period do.. 34.2 CocooNiNG OF First Brood. Cocooning takes places in the soil at an average depth of one-half inch, in fine sandy loam in the rearing cages, and this was found to be the usual depth in the soil in the field where the pupae were found. Of a total of 203 individuals recorded, 31 pupated on the surface of the soil, 154 in the upper half inch, 18 in the second half inch, Bui. 599, U. S. Dept. of Agriculture. Plate Work of the Striped Peach Worm (Gelechia confusella). Injury to peach foliage and characterist ic webbing. From pliotograph of limb taken from orchard About one-half natural size. (Original.) Bui. 599, U. S. Dept. of Agriculture. Plate II. The Striped Peach Worm (Gelechia confusella). Fig. 1.— Views of larvae: o, Dorsal; b, lateral; c, ventral. All enlarged about 6 times. Fig. 2. Eggs on peach, about natural size. Fig. 3.— Eggs enlarged about 11 times. (Original.) Bui. 599, U. S. Dept. of Agriculture. Plate III. The Striped Peach Worm (Gelechia confusella). Fig. 1. — Views of pupae: a,- Lateral; b, dorsal; c, ventral. Enlarged about 9 times. Fig. 2.— Pupal case, enlarged about 10 times. Fig. 3. — Adult, enlarged about 11 times. From photograph of living specimen showing natural position when at rest. (Original.) Bui. 599, U. S. Dept. of Agriculture. Plate IV. Work of the Striped Peach Worm (Gelechia confusella). Fig. 1. — a. Sand cherry terminal uninjured. Circles indicate place of egg deposition, b, Sand cherry terminal in early stage of injury by larvae, lowest leaf showing skeletonizing. Fig. 2. — Sand cherry terminal completely webbed by larvae. All reduced about one-third. (Original.) THE STRIPED PEACH WORM. 9 and none deeper. The larvae in the rearing cages cocooned from July 17 to August 9, but nearly full-grown larvae collected on sand cherry August 11 were cocooning from August 12 until September 14. The dates of cocooning for the season of 1916 are shown in Tables IV and V, and the length of the period in the cocoon for 17 individuals is shown in Table VI. The average length of the period in the cocoon was determined to be 12.4 days; the longest period, 21 days; and the shortest period, 9 days. Table VI. — Length of time spent in the cocoon by the first hrood of the striped peach icortn, 1916. Date of cocooning. Number of cocoons. Date of moth emer- gence. Days in cocoon. Date of cocooning. Number of cocoons. Date of moth emer- gence. Days in cocoon. July 17 2 3 2 1 1 1 2 July 2S Aug. 1 Aug. 2 Aug. 4 Aug. 6 Aug. 4 ...do.... 11 12 11 13 13 10 9 July 27. Aug. 7 Aug. 9 Aug. IS ...do.... ...do.... 11 July 20 Do.. 13 July 22 July 28 21 Do Aug. 1 . 17 July 24 Aug. 3 15 July 25 Total July 26 17 Maximum length of time in the cocoon days. . 21 Minimum length of time in the cocoon do.. 9 Average length of time in the cocoon do. . 12.4 Emergence of Fiust-Brood Moths. Table VII. -Emergence of first-brood moths of the striped peach tvorm at Benton Harbor, Mich., 1915. Date of emergence. Number of moths. Date of emergence. Number of moths. Aug. 4 Male. 3 Female. 4 1 3 4 3 9 1 2 1 Aug. 16 Male. 1 1 1 1 2 Female. 3 2 1 2 1 3 Aug. 20 Aug. 6 Aug. 21 Aug. 27 Aug. 9 Aug.2S Aug. 10 Aug. 29 Aug. 11 Sept. 1 Aug. 12 Sept. 11 Aug 14 . . Sept. 12 Total 9 40 Table VII shows that first-brood moths were emerging irom August 4 until September 12 in 1915, with the largest number on August 10. From 683 larvse collected on sand cherry July 28 only two moths subsequently emerged that season — one on August 28 and the other on September 9. The dates of emergence of first-brood moths in 1916 are shown in Table VI. 10 BULLETIN 599^ U. S. DEPAETMENT OF AGEICULTUEE. OviPOSiTioN OF First-Beood Moths. Table VIII. — Oviposition of flrst-brond moths of the striped peach tvorm at Benton Harbor, Mich., 1915. Date of oviposition. Number of eggs. Date of oviposition. Number of eggs. Aug. 15 . 178 26 10 Aug. 18 13 10 Aug. 16 Aug. 19 Aiif 17 Total 237 It will be seen from Table VIII that eggs were being deposited from August 15 until August 19, with the greatest number on August 15. The oviposition records are from the moths recorded in Table VII ; the late emerging moths failed to oviposit. On the morning of August 19, in transferring a peach on which eggs had been depos- ited, by mistake one moth was transferred. When the condition of the eggs was observed on the morning of xVugust 23 the moth had deposited 42 eggs in addition to those previously recorded. second brood. Incubation Peeiod of Second-Brood Eggs. Table IX. — Incubation period of second-brood eggs of the striped peach worm at Benton Harbor, Mich., 1915. Date of ovi- position. Number of eggs. Date of hatching. Number of larvae. Egg stage. Aug. 16 26 Aug. 31 Sept. 1 Sept. 2 Sept. 3 Sept. 5 Sept. 1 Sept. 2 Sept. 3 Sept. 3 14 2 3 1 4 5 8 1 17 Days. 15 16 17 18 21 15 15 16 15 Aug. 17 11 13 Aug. 18 Aug. 19 17 Total 67 55 Maximum length of incubation period days. . 21 Minimum length of incubation period do'. ... 15 Average length of incubation period do 15.6 In Table IX it will be seen that eggs began to hatch on August 31 and continued to hatch until September 3; the average incubation period being 15. G days. The Emergence of the Larva From the Egg. The larva cuts the top of the eggshell with its mandibles and eats the part cut away. By a wriggling movement it forces its head and thoracic legs out of the shell and with these legs on the edge of the shell pushes the rest of the hodiy out by the use of the caudal part of the abdomen. Of four individuals observed, 13 minutes was con- THE STRIPED PEACH WORM. 11 sumed by each from the first cutting of the eggshell until the larva was entirely free. Feeding Period of Second-Brood Larv^. Table X. — Length of feeding period of seeond-brood Inrvw of tJie striped peach worm at Benton Harbor, Mich., 1915. Date of hatching. Date of cocoon- ing. Number of cocoons. Days of feeding. Date of hatching. Date of eocoon- ing. Number of cocoons. Days feeding. Aug. 23 Oct. 7 Oct. 9 Oct. 12 Oct. 15 Oct. 24 Oct. 30 Oct. 9 Oct. 12 Oct. 24 Oct. 12 Oct. 22 Oct. 15 10 14 1 1 1 1 4 2 11 2 8 1 45 47 50 53 62 68 39 42 54 41 51 44 Sept. 1 Oct. 24 Oct. 27 Oct. 30 Nov. 2 Nov. 10 Nov. 14 Oct. 22 Oct. 24 Oct. 12 Oct. 24 2 2 1 3 8 2 4 1 1 1 53 Do Do 56 Do Do 59 Do Do 62 Do Do 70 Do Do.. 74 Aug. 31 Sept. 2 50 Do Do 52 Do Sept. 3 39 Sept. 1 Do 51 • Do Total Do 81 Maximum length of feeding period days. . 74 Minimum length of feeding period do 39 Average length of feeding period do 52. 1 Larvae were feeding from August 23 until November 14, the aver- age length of feeding period being 52.10 days. This late date of feeding is undoubtedly later than would have been possible in the field, for defoliation of peaches occurs previous to this date, al- though in the rearing jars the larvae secured the foliage to the twigs by the silken webs in such a way that it could not drop. CocooNiNG OF Second-Bkood Larv.e. Although cocooning normally takes place in the soil, 13 of 361 individuals recorded pupated in the webbed foliage in which they had lived as larvse. These pupae were closely rolled in the individual leaves but not attached to them, and no cocoons were formed. The dates of cocooning are shown in Table X. SUMMARY OF SEASONAL-HISTORY STUDIES. Table XI shows a summary of the seasonal-history studies made on material in rearing cages during the seasons of 1915 and 1916. Table XI. — Summary of seasonal-histori/ studies of the striped peach worm as observed by rearing during the seasons of 1015 and 1916. Observation. Season. Number of indi- viduals. Number of days. Average. Maxi- mum. Mini- mum. Length of life of moths of spring brood Incubation of eggs ol first brood Feedmg period of transforming larvse of the first brood. Feeding period of wintering lar\'a^ of the first brood Length of period in cocoon of first brood Incubation of eggs of second brood Feeding period of second-brood larvne 1916 1915 1916 1916 1916 1915 .1915 20 118 14 23 17 10.6 13. 18 29.6 34.2 12.4 15. C. 52.1 12 BULLETIN 599, U. S. DEPARTMENT OF AGRICULTUEE. PARASITES. While conducting the seasonal-history studies, it was found that the striped peach worm was parasitized by a number of insects. Table XII records the emergence of the Hymenoptera and Diptera which parasitized the 683 larvse collected on sand cherry July 28, 1915, and 60 pupae collected in May, 1916. Table XII. — Emergence of parasites of the striped peach worm (Gelechia con- fusella), Benton Harbor, Mich., 1915 and 1916. Date of emergence. Number of parasites. Date of emergence. Number of parasites. liate of emergence. Number of parasites. Diptera. Hymen- optera. Diptera. Hymen- optera. Diptera. Hymen- optera. 1915. Aug. 12... Aug. 13... Aug. 14... Aug. 15... Aug. 17... Aug. 18... Aug. 19... Aug. 21... Aug. 22... Aug. 23... Aug. 25... Aug. 27... Aug. 28... Aug. 29... Sept I... 1 1 3 3 1 4 1 1 2 2 4 1 1 1 2 1 1 1915. Sept. 2... Sept. 3... Sept. 4... Sept. 10. . Sept. 11.. Sept. 12.. Sept. 14.. Sept. 15. . Sept. 26.. (') 1916. June 11... June 13... June 15. . . 1 1 2 1 1 5 2 1 1 I 4 1 2 1916. June 18. . . June 23. . . June 25... June 29. . . July 2.... July4.... July 7.... July 10... July 12... July 13... July 14... (') Total.. 3 3 1 9 12 9 10 14 2 6 9 17 108 40 1 No record. The hymenopterous parasites were identified by Mr. R. A. Cush- man, of the Bureau of Entomology. Of 40 specimens submited, the different genera and species were represented as shown in Table XIII. Table XIII.- -Parasites reared from the striped peach tvorm. (Gelechia con- fusella), Benton Harbor, Mich., 1915 and 1916. Parasite, order and family. Number of indi- viduals. Stage of host col- lected. Parasite emerged from— HYMENOPTERA. ICH^fEUMONroAE. A ngitia discoocellellae Vier 20 1 1 1 8 2 7 2 61 2 Larva. Pupa. do do Do. do Do. Braconidae. do Pupa. do do Do. DIPTERA. Tachinidae— do Pupa. Larva and pupa. . . Pupa Do. BOMBVXnDAE— Do. THE STRIPED PEACH WORM. 13 The dipterous parasites which emerged in 1915 were identified by Mr. Harrison E, Smith, of the Bureau of Entomology, and those emerging in 1916 were identified by Mr. W. R. Walton, Entomologist in Charge of Cereal and Forage Insect Investigations. REMEDIAL MEASURES. Experiments were conducted in 1916 to determine the efficacy of arsenical sprays in the control of the striped peach worm. Plats were laid out in a sand-cherry thicket and sprayed with arsenicals according to the formulas in Table XIV, all of the adjoining sand cherry serving as checks for comparison. Table XIV. — Experiments for control of the siriped peach loorm, Benton Harbor, Mich., 1916. Plat No. Formula used. Date of spraying. Result of spraying. 1 2 3 Arsenate of lead powder, 1 pound to 50 gallons.. water. Arsenate of lead powder, U pounds to 50 gallons water. Check ; unsprayed June 29 ...do 5 per cent of terminals webbed. 3 per cent of terminals webl^ed. 90 per cent of terminals webbed. At the time of spraying, a few of the larvae had hatched and webbed a few terminals. The spray material was applied with a small compressed-air sprayer at a pressure of 70 pounds and sprayed just to the drip. The results of the spraying were very conclusive and both sprayed plats were almost entirely free from infestation when observed on September 19. RECOMMENDATIONS. The occurrence of the striped peach worm may be so local as to permit of the cutting out of the infested terminals or branches, and it will probably not occur in damaging numbers in orchards that are sprayed regularly with arsenicals for control of the plum curculio. Should the infestation be such as to warrant spraying, it is probable that a single application of arsenate of lead paste 2 pounds, or pow- der 1 pound, to 50 gallons of water to which 2 pounds of freshly slaked lime is added, applied when the first webbing of the leaves appears, will satisfactorily control this insect. 14 BULLETIN 599^ U. S. DEPARTMENT OF AGEICULTUEE. LITERATURE CITED. 1. Chambers, V. T, 1875. Tineina of the United States. In Ciiicinuati Quar. Jour. Sci., v. 2, no. 3. p. 226-259. Page 251 : Original description of adult of Oclcvliia confusella. 1878. Index to the Described Tineina ol" tlie Uniteil States and Canada. In U. S. Geol. and (4eog. Snrv. Terr., v. 4, p. 125-167. Page 142 : Lists Oelechia confusella Cham. 3. Smith, J. B. 1891. List of tlie Lepidoptera of Boreal America. 124 p. Philadelphia. Page 100 : Lists Gelechia confusella Cham, as No. 5342. 4. Pettit, R. H. 1899. Some Insects of the Year 1898. Mich. Agr. Coll. Exp. Sta. Bui. 175, p. 341-373, 20 fig. Pages 347-349 : First record of the injury by the larvae with notes on feeding habits and pupation. Description of larva and illustrations of larva and pupa. Remedies suggested. 5. MUKTFELDT, MaKY E. 1899. Description of adult of Deprcssaria pcrsicaeella, sp. nov. In Mich. Agr. Coll. Exp. Sta. Bui. 175, p. 348. 6. MUBTFELDT, MAKY E. 1900. New Tineidae, with life histories. In Canad. Ent., v. 32, no. 6, p. 161-166. Pages 164-166 : Deprcssarla pcrsicaeella Murt. to Gelechia and makes slight corrections in description of adult. 7. Dyar, H. G. 1902. A list of North American Lepidoptera. U. S. Nat. Mus. Bui. 52, 723 p. Pago 511 : Lists Gelechia confusella Cham, as No. 5719 with synonym persi- caeella Murt. 8. BuscK, August. 1903. A revision of the American moths of the family Gelechiidae, with descriptions of new species. In Proc. U. S. Nat. Mus., v. 25, p. 767-938, pi. 28-33. Page 859 : Lists Oelechia confusella Cham, with synonyms Depressaria pcrsi- caeella Murt. and Gelechia perslcaeella Murt. 9. Pettit, R. H. 1904. Insects injurious to fruits in INIichigan. Mich. Agr. Coll. Exp. Sta. Special Bui. 24, 79 p., 70 fig. Page 57 : Brief description of larva and moth, habits of larvae with place of pupation. Suggests remedies. 10. GOSSARD, H. A. 1911. Fall manual of practice in economic zoology. Ohio Agr. Exp. Sta. Bui. 233, p. 53-164. 13 pi. Page 125 : Notes that Gelechia confusella will probably occur in Ohio in the future. 11. Slingerland, M. v., and Crosby, C. R. 1914. Manual of Fruit Insects. 503 p., 396 fig. New York. Page 287 : Brief description of larva and moth, habits of larvae and recommenda- tions for control. PUBLICATIONS OF THE U. S. DEPARTMENT OF AGRICULTURE RE. LATING TO INSECTS INJURIOUS TO DECIDUOUS FRUITS. AVAILABLE FOR FREE DISTRIBUTION BY THE DEPARTMENT. Important Insecticides. (Fanners' Bulletin 127.) Spra.ving Peaches for the Control of Brown Rot, Scab, and Curculio. (Farmers' Bulletin 440.) San Jose Scale and its Control. (Farmers' Bulletin 650.) The Apple-tree Tent Caterpillar. (Farmers' Bulletin 662.) The Round-headed Apple-tree Borer. (Farmers' Bulletin 675.) The Rose-chafer. (Farmers' Bulletin 721.) The Leaf Blister Mite of Pear and Apple. (Farmers' Bulletin 722.) The Oyster-shell Scale and the Scurfy Sgale. (Farmers' Bulletin 723.) Orchard Bark Beetles and Pinhole Borers and How to Control Them. ( Farmers' Bulletin 763.) Aphids Injurious to Orchard Fruits, Currents, Gooseberry, and Grapes. (Farmers' Bulletin 804.) Control of Codling ]\Ioth in Pecos Valley, New Mexico. (Department Bulle- tin 88.) Walnut Aphides in California. (Department Bulletin 100.) • The Life History and Habits of the Pear Thrips in California. (Department Bulletin 178.) Studies of the Codling Moth in the Central Appalachian Region. (Department Bulletin 189.) Apple Maggot or Railroad Worm. (Entomology Circular 101.) How to Control the Pear Thrips. (Entomology Circular 131.) FCR SALE BY THE SUPERINTENDENT OF DOCUMENTS, GOVERNMENT PRINTING OFFICE, WASHINGTON, D. C. Grape Leaf-hopper in Lake Erie Valley. (Department Bulletin 19.) Price, 10 cents. The Lesser Bud-moth. (Department Bulletin 113.) Price, 5 cents. Homemade Lime-sulphur Concentrate. (Department Bulletin 197.) Price, 5 cents. Food Plants of the Gipsy Moth in America. (Department Bulletin 250.) Price, 10 cents. Life History of the Codling Moth in Maine. (Department Bulletin 252.) Price, 10 cents. American Plum Borer. (Department Bulletin 261.) Pricfe, 5 cents. The Parandra Borer as an Orchard Enemy. (Department Bulletin 262.) Price, 5 cents. The Dock False Worm: An Apple Pest. (Department Bulletin 265.) Price, 10 cents. Dispersion of Gipsy Moth Larvae by the Wind. (Department Bulletin 273.) Price, 15 cents. Miscellaneous Insecticide Investigations. (Department Bulletin 278.) Price, 10 cents. The Terrapin Scale: An Important Insect Enemy of Peach Orchards. (De- partment Bulletin 351.) Price, 15 cents. The Cherry Leaf-beetle: A Periodically Imported Enemy to Cherries. (De- partment Bulletin 352.) Price, 10 cents. The Grape Leaf-folder. (Department Bulletin 410.) Price, 5 cents. The Apple Leaf-sewer. (Department Bulletin 435.) Price, 5 cents. The Pear Leaf Worm. (Department Bulletin 438.) Price 5 cents. Insects Injurious in Cranberry Culture. (Farmers' Bulletin 178.) Price, 5 cents. The More Important Insect and Fungous Enemies of Fruit and Foliage of Apple. (Farmers' Bulletin 492.) Price, 5 cents. San Jose or Chinese Scale. (Entomolgy Bulletin 62.) Price. 25 cents. Pecan Cigar »Case-bearer. (Entomology Bulletin 64, Part 10.) Price, 5 cents. Spring Canker-worm. (Entomology Bulletin 68, Part 2.) Price, 5 cents. The Trumpet Leaf-miner of Apple. (Entomology Bulletin 68, Part 3.) Price, 5 cents. Lesser Peach Borer. (Entomology Bulletin 68, Part 4.) Price, 5 cents. 15 16 Lesser Apple Worm. (Entomology Bulletin 68, Part 5.) Price, 5 cents. Demonstration Spraying for Codling Moth. (Entomologj^ Bulletin 68, Part 7.) Price, 5 cents. Grape-leaf Slieletonizer. (Entomology Bulletin 68, Part 8.) Price 5 cents. Peach Tree Bark-beetle. (Entomology Bulletin 68, Part 9.) Price, 5 cents. Periodical Cicada. (Entomology Bulletin 71.) Price, 40 cents. Coddling Moth in the Ozarks. (Entomology Bulletin 80, Part 1.) Price, 10 cents. Cigar Case-bearer. (Entomology Bulletin 80, Part 2.) Price, 10 cents. Additional Observations on the Lesser Apple Worm. (Entomology Bulletin 80. Part 3.) Price. 5 cents. On Nut-feeting Habits of Codling Moth. (Entomology Bulletin 80, Part 5.) Price, 5 cents. Life History of Codling Moth in Northwestern Pennsylvania. (Entomology Bulletin 80, Part 6.) Price, 10 cents. Fumigation of Apples for San Jose Scale. (Entomology Bulletin 84.) Price, 20 cents. 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Life History of Codling Moth in Santa Clara Valley, California. (Ento- mology Bulletin 115, Part 3.) Price, 10 cents. Grape-berry Moth. (Entomology Bulletin 116, Part 2.) Price. 15 cents. Cherry Fruit Sawfly, (Entomology Bulletin 116, Part 3.) Price. 5 cents. Lime Sulphur as Stomach Poison for Insects. (Entomology Bulletin 116, Part 4.) Price, 5 cents. Fruit-tree Leaf-roller. (Entomology Bulletin 116, Part 5.) Price, 10 cents. Pear-tree Psylla. (Entomology Circular 7.) Price, 5 cents. Canker AVorms. (Entomology Circular 9.) Price, 5 cents. Woolly Aphis of Apple. (Entomology Circular 20.) Price, 5 cents. Buffalo Tree-hopper. (Entomology Circular 23.) Price, 5 cents. Pear Slug. (Entomology Circular 26.) Price, 5 cents. Box-elder Plant Bug. (Entomology Circular 28.) Price, 5 cents. Fruit-tree Bark-beetle. (Entomology Circular 29.) Price, 5 cents. Larger Apple-tree Borers. (Entomology Circular 32.) Price, 5 cents. Peach-tree Borer. (Entomology Circular 54.) Price, 5 cents. Plum Curculio. (Entomology Circular 73.) Price, 5 cents. Aphides Affecting Apple. (Entomology Circular 81.) Price, 5 cents. Nut AVeevils. (Entomology Circular 99.) Price, 5 cents. Two Destructive Texas Ants. (Entomology Circular 148.) Price, 5 cents. Mediterranean Fruit Fly. (Entomology Circular 160.) Price, 5 cents. ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 5 CENTS PER COPY WASHINGTO.N : GOVERNMENT PRINTING OFFlCg : 1917 Caylord Bros. Makers Syracuse. N. Y. PAI. IAN. 21, 1908 LIBRARY OF CONGRESS DDDDfla^lfc.31,