Jae a PR ARE TORY Ak EIS hil Sy BULLETIN No. 599 4 Ze f Contribution from Bureau of Entomology a L. O. HOWARD, Chief We Vashington, D. C. PROFESSIONAL PAPER March 16, 1918 THE STRIPED PEACH WORM. CONTENTS. Page Page. Introduction Beeiseeetscesaenasccscacesacsnse 1 | Description—Continued. FO ACIDE CECB COOBE BOS OMEE HE Sees es meet 2 Mhelanvas sits sites hele eeine Sees eee 4 eee sane sin~ ce acscitowes es 2 ‘THO PUPAsc cases cetsc ccs ese ec eee 5 Food QUEL see Se 3 TER ElCOCOOM Saas saat ao ae eae tec e eerie ee 5 )) Feeding habits of the larva.....-....-.--.... 3 | Seasonal history and habits..............-.. 5 _ Character of injury on peach.......- penans Here 3 Summary of seasonal-history studies... . 11 _ Character of injury on sand cherry.......---- Sik wibarasitesesss-a teas cee cess rae See oe 12 MPEIEEIN PANG. = 5 ao sis oe oo .- 5 --'s easiness 45 Remedialimeasuness--2-osoce2a- iceeece eee 13 ; pac ine Be Ge ae he ele tai eerie eee Aral Tsiteraturey cited sscke seca see tance cee ae 14 CIT GE A Ae eee eee ee 4 INTRODUCTION. 7 The striped peach worm (Gelechia confusella Cham.), although described in 1875, has received little notice as an economic species. The larvee feed in conspicuous webs on the foliage of the peach and on sand cherry (Prunus pumila) in smaller but more compact webs. While at present this insect is not a major pest on peach, the larvee ave 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 the insect during the seasons of 1915 and 1916. The biological data secured, toocther with descriptions of all the stages and suggestions for control, are recorded in this paper. 17The writer is indebted to the following members of the Bureau of Entomology staff: ‘the E. H. Siegler for the photograph used in Plate I, figure 1; to H. K. Plank for Plate , figure 1, and Plate III, figures 1, 2, and 3; to J. H. Paine for Plate II, figures 2 and 4 5 ‘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 larve 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 larvee 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 persicacella 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 persicacella 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 under 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., 1899. Gelechia persicaeella Murt., 1900. The writer has accepted the name “striped peach worm,” as it seems to distinguish this insecf 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 Be PR 15 1918 \ ? an Pa << 5? if THE STRIPED PEACH WORM. 33 \ FOOD PLANTS. Previously published notes have recorded G. confusella as feed- ing only on peach foliage. During July, 1915, the writer observed a webbed condition on sand cherry (Prunus pumila) (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 larve 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 irregular 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 larve on the foliage. The webs spun by the larve 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 larve been observed to feed on the fruit. Larve of varying sizes are found in the same webs, indicat- ing the probability of repeated oviposition in the same terminal. From 2 to 12 larve 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 larvee enlarge the webs, they extend them along the branches, gradu- ally including more and more foliage. 4 BULLETIN 599, U. S. DEPARTMENT OF AGRICULTURE, DESCRIPTION. THE ADULT. (Pl. III, fig. 3.) Because of its completeness the description of the adult is copied from Murtfeldt: Antenne dark fuscous, indistinctly pectinate and banded on the under side with pale buff. Palpi long, exceeding the vertex. Basal joint short, pale; sec- ond joint one-third longer than apical. Brush 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 6. Tongue long, sparsely scaled. Vertex dark brown. Face cream white. Thorax and tegulie 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 tibie. Alar expanse from 16 to 17 mm. THE EGG. (Pl. 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. (Pl. I, 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 larva 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 are about equidistant from each other and of about the same width as the spaces between them, color reddish-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 larve (PI. I, 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. (EIS figs) 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 hight 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. (BIS Th, figs 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 pupe 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 larve. There is one full brood and a partial second brood. The rearing studies began with the collection of a quantity of larvee 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 pupe 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 place 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.—Hmergence of spring brood of moths of the striped peach worm in 1916. Date of Number Date of Number Date of Number Date of Number observation. | of moths. || observation. | of moths. || observation. | of moths. || observation. | of moths. May 22..... 1 || June 13...... 12 || June 29...... 60 || July 13....... 3 May 30....... 2Hidunetssss-22 BOE OUlye Zee oe ce 32 || July 14....... 3 Wun Oseeee a 1 || June 17...... 24 || July 4........ 14 —_—_——_—_ June G2eecces 4 || June 18...... PI Utley a5 505e 3 Total... 364 UUNGiSe access Sy lek iobaye\ Oa bee 6G | Malye ccs e5 18 June kOe se ae Gh |. oname3 Sse AS || aly lOc seer 4 ume We seece Biel! dibs eaaaee se DAM igdiiliypbeses cee 2 OVIPOSITION OF SPRING BROOD OF 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.—Length of life of 20 moths of the spring brood of the striped peach worm, 1916. Number of Days of Number of Days of moths. life. moths. life. 1 4 3 14 5 6 1 16 5 9 1 28 4 12 20 Maximum Jength of life pe. - tose Osc Sa “eet eee eee eee days.. 28 Minimuntlength, of life. Ho. se, eo ee OP EERE EE Ee eRe emer Ke Kove oa! Average length of lifé 5:54.05 ced. cee ee eet ceed d0.45271056 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 will 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 IIl.—IJncubation period of first-brood eggs of the striped peach worm at Benton Harbor, Mich., 1915. Number Number Date of Date of ~ . | ofeggs | Dateof | Number paar ofeggs | Date of | Number af ee depos- | hatching.| of larvae. | E88 Stage. ba depos- | hatching.| of larvae. [E88 Stage. ee ited : ited. Days. | Days. June 2... 1i | June 15. 11 13 June 26. 2 10 June 16.. 1 13 | June 16.. 6 |4June 27 2 11 June 3... 6 |{June 19.. 2 14 June 28 1 12 June 20.. 1 15 June ze a 10 June 5... 4] June 21.. 3 16 June 29 1 11 June 20 23 14 || June 18.. 29 Hs 20 5 12 June 23.. 1 Li| uly ¢ June 6... 28 June 24.. 3 18 | June 20.. 4 | June 30 2 10 June 25.. 1 19 | June 26.. 5 | July 7 1 11 June 10.. 2} June 23.. 2 13 —— —_————- June 12.. 20 | June 26.. 20 14 Total -.| MLS aosmce care ‘LOG erctcrezies June12.. 3 | June 27.. 2 15 | * days.. 19 Maimumiere stages sabe seeh Ade ee Bee eee en ee egy ste ota TTI UIE LE SLAC Ve ean ve oe ne ie ciste ns Sas ewes Be a porch nS a a Bias a mornin aah eh sie 10) Atverage egg stage. ..2-. 2.2 -e ee. soc. - 222-2 one eee eee ee cee nec e nner eneee do-.... 13.18 8 BULLETIN 599, U. S. DEPARTMENT OF AGRICULTURE. FEEDING PERIOD OF FIRST-BRoop LARVA. The feeding period of the larve in the rearing cages in 1915 ex- tended from June 15 to August 5. In 1916, larve 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 larve, and 34.2 days for over- wintering larve. 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 larve had left the webs and newly formed pupz were to be found in the soil. Observations made on September 14 showed that from 95 to 98 per cent of the larve had left the webs. TasLE LV.—Length of feeding period of transforming first-brood larve of the striped peach worm, 1916. Date of | Number Date of | Number Date of hatching. |ofcocoon-| of ee Date of hatching. | cocoon- = pe of ing. | cocoons. | 1¢¢48- ing. | cocoons. | *°¢8- J une Oya eae ee 4 oly 3 é 23) SNe 2puee sence ee H td 17 2 = (Bet 5 SeGacoce uly 22 30 On ee takes uly 20 Dosa wri ss July 24 1 32 Dota s a as July 26 1 31 DOr tases ssece July 26 1 34 DOs:45h eck ans July 27 2 35 Total taveare at eee BP eS hese oe 1D Oe Sees ecse July 28 u 36 Maximumilength of feeding period’: 222 /ay\242 bates eee eae ee ee eee ees days.. 36 Minimum length of feeding period......-. wih ahd aid tee SOIT ats I AB Rh PN Cs do.. 22 Average lerigth of feeding periods! 32 2 )2222 5h. So ER ee See ee cet ee do.. 29.6 TABLE V.—Length of feeding period of wintering first-brood larve of the sured peach worm, 1916. Date of | Number ! Date of | Number Date of hatching. | cocoon- of Pe Date of hatching. | cocoon- of eatin! ing. | cocoons. ONS. ing. | eocdons. 7 June. 224. 5 se ee July 20 2 Q8ei| Tumew2ee ihe ae Aug. 9 i 48 Dota Hele July 23 1 S1|| Tunes aoe eee July 17 1 22 Dots eee July 24 2 32 Dos. eee July 26 3 31 DOW as eee ee July 27 1 35 || July 5 July 31 1 26 Dozte eieee ee July 28 4 36 Doss. iy ees Aug. 1 1 27 DOES ba July 31 3 39 Dosti sore eee July 30 2 38 Wotal jaa fel tees eeee 23) |< impair Dos. Pee Aug. 8 1 47 Maximum length of feeding period Minimum Jensth offeedingeiperiod = 2: stickers oe cee sacs ose A-veraze lengthiot feeding’ pertods-)f-2sesae. ss aeeee eee eee ees ane CocoONING OF First Broop. 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 pupe 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, Bul. 599, U. S. Dept. of Agriculture. PLATE |. WoRK OF THE STRIPED PEACH WoRM (GELECHIA CONFUSELLA). Injury to peach foliage and characteristic webbing. From photograph of limb taken from orchard. About one-half natural size. (Original.) PLATE II. Bul. 599, U. S. Dept. of Agriculture. Acme a seee™ ” a, a a Oye a api apeds > Mh qa” ire ® 8 ey oie: d THE STRIPED PEACH WoRM (GELECHIA CONFUSELLA). All enlarged about 6 times. Fie. 2.— Fig. 1.—Views of larve: a, Dorsal; 6, lateral; c, ventral. p Eggs on peach, about natural size. Fic. 3.—Eggs enlarged about 11 times. (Original.) Bul. 599, U. S. Dept. of Agriculture. PLATE III. THE STRIPED PEACH WorRM (GELECHIA CONFUSELLA). Fig. 1.—Views of pups: a, Lateral; 6, dorsal; c, ventral. Enlarged about 9 times. Fia. 2.— Pupal case, enlarged about 10 times. Fic. 3.—Adult, enlarged about 11 times. From photograph of living specimen showing natural position when at rest. (Original.) Bul. 599, U. S. Dept. of Agriculture. PLATE IV. WORK OF THE STRIPED PEACH WORM (GELECHIA CONFUSELLA). Fic. 1.—a, Sand cherry terminal uninjured. Circles indicate place of egg deposition. 6, Sand cherry terminal in early stage of injury by larvee, lowest leaf showing skeletonizing. Fic. 2.—Sand cherry terminal completely webbed by larvee. Allreduced about one-third. (Original.) THE STRIPED PEACH WORM. 9 and none deeper. The larve in the rearing cages cocooned from July 17 to August 9, but nearly full-grown larve 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 brood of the striped peach worm, 1916. Date of Date of Number ° Number a Date of cocooning. of iaetlt Days Date of cocooning. of mou Days in cocoons. 5 : cocoons. Us| MSbELo ste gence. gence. WEL ee loess ot 2] July 28 ll 1 | Aug. 11 Lita? Doe See 3} Aug. 1 12 1| Aug. 9 13 Cielke 27 5 eee) aie 2) Aug. 2 11 1} Aug. 18 21 iOS ACs Sea 1} Aug. 4 13 Y |=-edoks 17 bt ATE Se a ae 1 | Aug. 6 13 Tp |k-2do se 15 I A 1} Aug. 4 10 athveoGe ss oo. < 2 |...do. 9 1 fo ae ees a tees Maxamiry lenetivof time in Ene:iCOCoOn...2.-. -..s0222scna-2-tesceeec ee cee days.. 21 Mriarnm: Jenpth' of fim6é i the COCOON= kos = sans ose oe oe terse hake bee bos dace do.. AvetarolenppM on eimein the COCOON 2% .jc2 esac oa cesceasicecs cccccccececcoccens do.. 12.4 FEXMERGENCE OF FIRST-BRoop Morus. TasLtE VII.—lHmergence of first-brood moths of the striped peach worm at Benton Harbor, Mich., 1915. Date of emergence. | Number of moths. || Date of emergence. | Number of moths. Male. Female. Male. Female. 0 0 3 0 1 1 0 0 3 1 0 0 4 0 2 0 3 1 1 0 9 1 0 3 1 0 2 0 2 0 1 0 1 2 3 9 40 Table VII shows that first-brood moths were emerging trom August 4 until September 12 in 1915, with the largest number on August 10. From 683 larve 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. DEPARTMENT OF AGRICULTURE. OVIPOSITION OF First-BRoop MorTHs. TABLE VIII.—Oviposition of first-brood moths of the striped peach worm at Benton Harbor, Mich., 1915. Date of Number Date of Number oviposition. of eggs. oviposition. of eggs. ANP Seek es 178 AUBT1B see ak: fe: 13 AM; LOi ease se eee 26 Auge lowe ees a-s- 10 ANE. Wl geerct ater 10 SS Rotalen sss: 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 August 23 the moth had deposited 42 eggs in addition to those previously recorded. SECOND BROOD. INCUBATION PERIOD OF SECOND-BrRoop Eacs. TABLE IX.—IJncubation period of second-brood eggs of the striped peach worm at Benton Harbor, Mich., 1915. Date of ovi- Number | Date of | Number Egg position. of eggs. | hatching.| of larve.| stage. Days. Aug 16: .-c.c2" 26 | Aug. 31 14 15 Lae eee pet Sept. 2 16 i Seas Vlie Sept. 2 3 17 Seti oeiers Sept. 3 1 18 vee ae Sept. 5 4 21 SARIS, 522 Beek 11 | Sept. 1 5 15 Ang: Tay ss2ceee 13 | Sept. 2 8 15 Soeseetese Sept. 3 1 16 AT. 19 ee ee 17 | Sept. 3 17 15 Totals.eree CY GUC See Se eee 55! Il eeeemeree Maximum length of incubation period....... days.. 21 Minimum length of incubation period........do.... 15 Average length of incubation period..........do.... 15.6 In Table TX it. will be seen that eggs began to hatch on August 31 and continued to hatch until September 3; the average incubation period being 15.6 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 body 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-BRoop LARVA. TaBLe X.—Length of feeding period of second-brood larve of the striped peach worm at Benton Harbor, Mich., 1915. Date of | Number Days Date of | Number] Days Date of hatching. | cocoon- of of Date of hatching. | cocoon- of of ing. cocoons. | feeding. ing. cocoons. | feeding. a\"Octe 2 af 10 AGU Geptialsne sete ves. Oct. 24 2 53 Oct. 9 14 47 DOt see tee ee Oct. 27 2 56 Oct. 12 1 50 WD) OMe aa eane Oct. 30 1 59 Oct. 15 1 53 DO emeee ee eae Nov. 2 3 62 Oct. 24 1 62 DON cone Pecos Nov. 10 8 70 Oct. 30 1 68 1D YO) eee Se Nov. 14 2 74 Oct. 9 4 393\|SSeptetscsassecsenee Oct. 22 4 50 Oct. 12 2 42 (DORA S ee atbree Oct. 24 1 52 Oct. 24 11 54; |Septase nyse seceene Oct. 12 1 39 Oct. 12 2 41 DOe once ae ace Oct. 24 1 51 Oct. 22 8 51 Oct. 15 1 44 Molale cc Se eer ae 2) He ees ane Maximuamilengthioffesding period: 4225S: sooens nee ae wanes cee « onanncseseueioe days.. 74 Minimum iene thiofiesding period: is. 2 cen 4.<2 socic soe eee se atlce cboecenccesmecs dote2239 ASVeTAre Ene ti Oli COGIMEsPELIOG -mieceinccls oneiccec ced jet amepmmek sekae ccs wool capecee doses 2 52.1 Larve 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 larve secured the foliage to the twigs by the silken webs in such a way that it could not drop. CocooNING OF SECOND-Broop LARV2. Although cocooning normally takes place in the soil, 13 of 361 individuals recorded pupated in the webbed foliage in which they had lived as larvee. These pup 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-history studies of the striped peach worm as observed by rearing during the seasons of 1915 and 1916. Number of days. Number Observation. Season.| of indi- y a wievels: | aversee.| rma: +1 dae Length oflife of moths of spring rand at eases kit 1916 20 10.6 28 4 Incubation of eggs of first brood................--.---- 1915 118 13.18 19 10 Feeding period of transforming larvee of the first brood.| 1916 14 29.6 36 22 Feeding period of wintering larve of the first brood ....| 1916 23 34.2 48 22 Length of period in cocoon of first brood............--- 1916 17 12.4 21 9 Incubation of eggs of second brood...........-.-------- 1915 55 15.6 21 15 Feeding period of second-brood larve............------ 1915 81 52.1 74 39 12 BULLETIN 599, U. S. DEPARTMENT OF AGRICULTURE. 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 larve collected on sand cherry July 28, 1915, and 60 pupe collected in May, 1916. TABLE XII.—Hmergence of parasites of the striped peach worm (Gelechia con- fusella), Benton Harbor, Mich., 1915 and 1916. Number of Number of Number of parasites. parasites. : parasites. Date of Date of Date of emergence. a emergence. 7 emergence. a . ymen- . ymen- . ymen- Diptera. optera. Diptera. optera. Diptera. optera. 1915. 1915. 1916. 76 (ga Bee 0 3 || Sept. 2... 0 1 || June 18 Ot eee See Aug. 13.. 0 3 Sept. 3... 1 0 || June 23 5 ele see Aug. 14... 0 1 Sept. 4... 0 1 June 25 | ees aye Aug. 15... 0 4 Sept. 10.. 1 1 | June 29 9) 2 eee Aug. 17... 1 1 Sept. 11.. 0 2 July 2 12) \ oo eee Aug. 18.. 0 1 Sept. 12.. 0 4 || July 4 + aa eS ES ee Aug. 19.. 0 2 Sept. 14.. 2 0); July 7.. HO! |e ea eee Aug. 21... 0 2 Sept. 15-. 0 1 | July 10 14 ENE = See Aug. 22... 1 4 Sept. 26.. 1 0 | July 12 2) eee Aug. 23... 0 1 (1) 0 2 || July 13 6 eee Aug. 25... 0 1 || July 14 ie aera. Aug 278 0 1 1916. () py il ewes Aug. 28... 0 2 June 11. 1 ee Sere SSS Aug. 29.. 0 1 June 13. Ot | tee ito | Total 108 40 Sept 1-.. 0 1 June 15. PAN Ieee Ooi am | 1No 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 worm (Gelechia con- fusella), Benton Harbor, Mich., 1915 and 1916. Number GeO : - 4. | Stage of host col- Parasite Parasite, order and family. ot ings acre emerged from— HYMENOPTERA. ICHNEUMONIDAE. Angitia discoocellellae Vier... .\/:-2---02-22222 22202: 20)|Larvas.:2.ce25sser Pupa. Cremastusiforbesit Weed. 24. .f eset 2st as ade Ve Fee GO ais sinetemnes No record. CreMmastUs'SP sop scer «on nc se caress oslioe a aso eee de Goes. seceeeee Do. Bpiurasindagator Walsh... ....2 sc. sce. ee cance i SSeS WOE eater Do. BRACONIDAE, Apanteles; gelechiae Wiens as x atene oe ee ch eee eee Suleeeee Os S.ceceeetare Pupa. Alscogaster COnpOCapSae NiICY sacee ee aan ee eee ae ae Pa Maree (eee decaaso = No record. Epirhyssalus atriceps AShm. 3 f,4 9 ..--.-------- fi Noose WOR endosooec Do. DIPTERA. TTACHINIDAE— Mcoriste pystesWeallkess tc. cce seers eee 2 eon eee 74a Eee Ose eksscetecs Pupa. Rrontinaaneitiy, Walk ses see nes a eeeeena 61 | Larva and pupa... Do. BOMB YLODAE— Anthraz lateralis Say. 22. 2s . 26 \ecee saee skeet 2:), Bupa wt: S222 eooee 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.—Herperiments for control of the striped peach worm, Benton Harbor, Mich., 1916. eae Formula used. | eee Result of spraying. 1 | Arsenate of lead powder, 1 pound to 50 gallons. -| June 29 | 5 per cent of terminals webbed. water. 2 | Arsenate oflead powder, 14 pounds to 50 gallons -..do....- 3 per cent of terminals webbed. water. | aeGHecksunsprayed sh wiss 222. 22c5l he Scleet ce clecaesanees 90 per cent of terminals webbed. At the time of spraying, a few of the larve 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 i On =] 10. alate BULLETIN 599, U. S. DEPARTMENT OF AGRICULTURE. LITERATURE CITED. CHAMBERS, V. T. 1875. Tineina of the United States. Jn Cincinnati Quar. Jour. Sci., v. 2, no. 3, p. 226—259. Page 251: Original description of adult of Gelechia confusella, 1878. Index to the Described Tineina of the United States and Canada. In U.S. Geol. and Geog. Surv. Terr., v. 4, p. 125-167. Page 142: Lists Gelechia confusella Cham. SmitTH, J. B. 1891. List of the Lepidoptera of Boreal America. 124 p. Philadelphia. Page 100: Lists Gelechia confuscila Cham. as No. 5342. Perrin wee 1899. Some Insects of the Year 1898, Mich. Agr. Coll. Exp. Sta. Bul. 175, p. 341-373, 20 fig. Pages 347-349: First record of the injury by the larve with notes on feeding habits and pupation. Description of larva and illustrations of larva and pupa. Remedies suggested. MURTFELDT, Mary EH. 1899. Description of adult of Depressaria persicaeella, sp. nov. In Mich. Agr. Coll. Exp. Sta. Bul. 175, p. 348. MURTFELDT, MAry 9H. 1900. New Tineidae, with life histories. Jn Canad. Ent., v. 32, no. 6, p. 161-166. Pages 164-166: Depressaria persicacella Murt. to Gelechia and makes slight corrections in description of adult. Dyar, H. G. 1902. a Life History of Codling Moth in Santa Clara Valley, California. (Ento- mology Bulletin 115, Part 3.) Price, 10 cents. ae 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. Sa Fruit-tree Leaf-roller. (Entomology Bulletin 116, Part 5.) Price, 10 cents. — Pear-tree Psylla. (Entomology Circular 7.) Price, 5 cents. oe Canker Worms. (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 Weevils. 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