Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. 7. PP Yee Sy aye | iettmait. | ber of lottinait, | Per of % Sire Naren | ty aoa Maxi- Mini- te teO | Tatve. | pe - Maxi- Mini- ; erase-| mum. | mum. sa hia eed ie crip ia iMac eis sr 9 a June 27 2 8. 00 8 8 || July 15 49 6. 37 15 2 29 1 7.00 7 i 16 55 6. 76 21 3 30 3 6. 00 6 6 17 43 7. 40 23 2 July 2 + 6. 00 10 4 18 38 5. 50 13 4 3 6 8. 00 10 5 19 22 6.77 24 2 4 6 5. 50 6 5 20 17 5. 41 12 3 % 5 3 6. 00 ii 5 21 16 4, 94 11 1 + 6 % 5. 50 6 5 22 21 5. 00 16 2 4 7 12 5.17 ll 4 23 il 6.18 19 2 ie 8 8 5. 00 10 4 24 of 8. 29 28 4 4 9 15 4. 53 7 4 25 3 9. 67 21 3 5 10 19 5. 37 16 3 26 3 4,33 5 4 11 28 6. 36 20 3 27 2, 3. 50 4 3 12 40 5. 50 14 4 28 2 14. 00 24 4 13 43 6. 16 16 3 29 2 15. 50 23 8 - * 14 56 ays: 14 3 30 1 6. 00 6 6 3 } 4 prratena TT TIMEIE NN) be UGG” fe ek ay A ag ee cr Be oo oe oa been we ch de wen Sob wis co eteplee 540 Peo LON aan COCOGnIne NETLOG INOaVS a. ya eh S| Sc eRe ee 6.12 Bese sac NGF COCGOMINE PTIOG ML OGYS . <2. sac i052 wns ot a sow enon wwe eas aan acne et sspanaes 28 PH ORE EACOr COCOGIINE: PETLOGAD GAYS wiacosssscadccadeyodste re se cedteoseedee taeda neseseie 1 46 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. PUPZ OF THE FIRST BROOD. Time of pupation.—Pupation by larvee of the first brood was first observed on oe 5 and continued daily, with four exceptions, until August 15. This is shown in Figure 27, which also gives the date of maximum pupation as July 23, when 52 larve transformed. SIR? {ST ae [ae gi bay WL Wes | Sn 8 ° NUMELR OF PULIFE RQye FANLCATAIWIL AVEO FOCSATH7E oN & & oR RaGokh SS eS PUL RSH | i ALY: SULLY nue Fia. 27.—Pupation of the first brood of the codling moth at Yakima, Wash., 1921. Length of pupal stage-—Table 39 shows the length of the pupal stage of 491 pupe. an a TaBLE 39.—Length of the peat stage of pupez of the first brood of the codling moth, Yakima, Wash., 1921. Pupal period in days. Pupal period in days. Dateot | Number ____—__—_ ||. Date of pupation. : ee Minj- || Pupation pup. | ,. axi ini Average.| mum. | mum. July 5 2 11. 00 11 11 |} July 24 6 5 12. 80 14 1 7 2 14. 50 15 14 26 8 1 11. 00 11 ll 27 9 3 13. 00 14 12 28 10 3 13. 00 13 13 29 11 6 12. 67 17 11 30 12 17 13. 18 16 11 31 13 14 12.14 14 11 Aug. 1 14 10 12. 70 14 12 2 15 13 12. 62 18 ll 3 16 26 13. 62 27 10 5 17 32 13. 00 20 11 6 18 24 12. 75 20 9 7 19 43 12.77 27 6 8 20 28 12. 21 14 11 9 21 30 12. 20 13 11 12 22 | 45 11. 89 15 6 21 23 | 49 12. 78 26 10 | | Total number Of PuUped. .- ~..< 10 11| 186 23 30 9 WA NA. 13°15. de. : Aug. 15 | Sept. 1 | 1 2 19 19 234m 24 9 4 5 | Aug. 14] Aug. 15 |...do....{ Sept 2 | 1 1 19 19} 114 25 24 10 14 | Aug. 15| Aug. 18} Aug. 23 ) 3 8 16 18 | 232 26 15 5 10 | Aug. 16 do.. Aug. 22 | Aug. 30 2 6 13 14} 135 27 5 2 3 | Aug. 17] Aug. 20 |...do. Aug. 27 3 5 8 10 65 28 13 5 8 | Aug. 18} Aug. 19 | Aug. 20 } Aug. 31 1 2 13 13 95 29 16 9 7; Aug. 19} Aug. 20} Aug. 25 | Sept. 7 1 6 19 19; 414 30 15 4 11 | Aug. 20| Aug. 23 |} Aug. 24] Sept. 5 3 4 14 16 99 31 15 9 6 | Aug. 21 | Aug. 25 | Aug. 30 | Sept. 9 a 9 16 19 | 296 32 5 4 1 | Aug. 22| Aug. 29 | Aug. 29 | Aug. 29 7 7 1 7 2 33 8 5 3 | Aug. 28 }|...do....| Aug. 30 | Sept. 26 1 2 29 29} 104 34 10 2 8 | Aug. 29] Aug. 31 | Sept. 3 | Sept. 7 2 5 8 9} 119 ISU nn ER ae = Ne a a ee ee ee 174 S079 [1s. bor 1 4.29.2 eee ORESTSUPTY EET a ee tad See Se aes es, OS aN ae ee a ee a 7 9 29 29) (eee UVRILESENEATI ey rns tts Seer se pee tee Ae ee i a 1 2 1 Thal Popes Snare rel Tan UTTER ION HL Seere 22 ne ee ae ee Cee ae ee. ache lee imma cients Daeeee cee 359 SUMP SREP BUCA E ESS ETN) CONANT Sect ss ene ete Gann EN Sn cate aidacinn binieint@ cine ecu Same slums 645 PRICE HMEte ra ein naS he eee oie es ee ee eR eS ee heel sau e J bine eee einer 1, 004 OETA CONGR De 1 me ete ete eee a's Mid anh mame Ue clown emenice jomamaoeraeee 13, 154 48 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. Length of life of moths.—Table 41 shows that the average length of life of 356 male moths of the first brood was 11.72 days; of 643 females, 11.39 days. 80 75 d ZN ; 80° Heor 75°X RY 70°® K50 6° S45 60° rr 5e°% 8 Bors 4 AT A Sees baat aa Wit | SP Pe Se PRE Sees y=) NGM MRT A EO U2 a i NY SpA PW | EY DS NS EY RP CPT NE ee Ter wae eB Ss 1 A a a il WA q o ALY ACA PPA POPE OPAL PR PPP HPAL APRA NY AAV AO PW VN ef Vout VE tem ee ae 6 46 2 &€& Gl OS JOKES 120) 2S SG, ~aiuye , HULY AUGUST SEPTEMBER OCTOBER Fic. 28.—Emergence of the first and second pros, ot moths of the codling moth at Yakima, ash., : TasLe 41.—Length of life of male and female codling moths of the first brood, Yakima, Wash., 1921. | Male. | Female. Male. Female. Male. Female. = um- Num Num- um. Num- Length | her of uae ber of Ratt ber of pene ber of hapett ber of ear ber of of life ee ©. | moths. || Of 4 Imoths.| 44°: | moths. || 0 44®- |moths moths ; | Days Days. Days Days Days Days. | : 1 3 1 3 14 14 35 26 1 26 2 \ oz 1 2 1 15 17 15 23 27 1 27 1 3 4 3 10 16 16 16 28 28 2 28 1 4 18 4 22 17 9 17 31 29 1 29 0 5 14 5 21 18 5 18 12 30 1 30 0 6 21 6 44 19 1l 19 20 34 1 34 1 7 36 7 65 20 5 20 8 35 1 35 0 8 20 8 37 21 12 21 6 37 1 37 0 9 24 9 49 22 4 22 6 39 1 39 0 10 33 10 68 23 2 23 4 50 0 50 1 shi 29 11 46 24 2 24 3 | 12 21 12 44 25 2 25 7 || Total .. 356 | Total.| 643 1a] 8 | i3| 44 | | Average length of life of male moths, 11.72 days; female moths, 11.39 days. Maximum length of life of male moths, 39 days; female moths, 50 days. Minimum length of life of male moths, 1 day; female moths, 1 ‘day. LIFE CYCLE OF THE FIRST GENERATION. Table 42 shows the periods in the life of 490 individuals of the first generation from the time of deposition of the egg to the emergence of the adult. From this table the average life cycle is found to be 54.14 days, to which must be added 1.74 days, the average length of the preoviposition period, to give the complete life cycle from egg to egg, which in this case is 55.88 days. All larvee were brought through the f eeding period by the stock-jar method. ——— BSR BSB BS SMES SEA AS AES RE EAS SE SSeS SS See eee eee THE CODLING MOTH IN THE YAKIMA VALLEY. 49 TaBLe 42.—Life cycle of the first generation of the codling moth as observed by rearing, stock-jar feeding method, Yakima, Wash., 1921. Num- Date of be In- egg de- indi- euba-|- position. vid- tion uals. May 24 2 9 2 3 9 27 5 8 29 3 7 June. 1 8 7 2 17 il 2 il 8 a 18 8 3 9 9 4 15 9 4 30 10 5 11 10 6 4 iol 6 12 12 7 30 12 8 34 12 9 59 12 10 60 12 12 51 il 15 15 9 16 33 9 18 10 8 19 18 8 20 7 8 21 5 8 22, 4 8 23 6 8 22) 4 9 25 1 9 26 1 9 Dei 2 9 28 1 9 29 1 9 490 |10. 22 74366°—24 Larval feeding period. . Cocooning period. Pupal period. " Life cycle.} Aver- | Maxi-) Mini- age. |mum.|/mum. Days. Days. Days. 31. 00 34 28 1 Add 1.74 days for complete life cycle. 4 Aver- | Maxi-| Mini-| Aver- |Maxi-| Mini-} Aver- | Maxi-| Mini- age. — Ee SS SO Oe SSS saa vaste Aba eI SD SSAC ISE Sa =P mum.{mum.| age. 8. | Days.| Days. CORP PP OWN PWR WRHWWPRWNWHEPWWW RP RWW ROD — mum. |mum., Days. | Days.| Days. 12. 50 13 12 age. |mum.|/mum., Days. | Days.| Days. 58. 00 60} 56 50 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. THE SECOND GENERATION. EGGS OF THE SECOND BROOD. Time of deposition.—The complete period over which the first brood of moths laid eggs extended over the 91 days beginning July 15 and ending October 13, although 12,021 eggs, or 77 per cent of the total number, were deposited during the four weeks beginning foes OE TO WT NONE ED | Ee CE TN SE Es fo 5 te ee | a et eed ORs (oD BS SS is SS Se 47BO = x Bor pA PE og PRY, | TS RE ES Te APL OS VA Tal i Se ee a ee a SIE Owe wee As Be 1S pee orl al ies te ee [onl ae ae Pe a pA RY EN A | Ts A 8 ds ABS, El Bel ef 7 ee ee LAL IGN AL 4 as\ oe el oll Ar (gee gt Pk Ds eee ge: Weuae ee ee jo Aas Wd EE Te Ser ir eae = opp sed ela: de [feebepee | oo] Labo |izel abe ane Ps tree h Sooo San OS 2 BT ee a ee Le | y aod SS PN OTT WE BE 5 TE TS Oe ee ee Rw ee Ow en ST es eer es eA eS a ea a TS ee Fe Ss Te Ee A aS ETE DTG Te WE [se ee ef erode ae a a DT Pee rion ee Se a ae es re eS es ee pririogh ed Pe DD A | DS Fs es Ee = ed oe nee Beg i= ttt eel Bars [Penl Udo Neotel te qmrae oe Q ————————————— ee N pagers 3k SE Pes Sib OT ee Sos Ma DAE RE GH | FN Be ee pee Ss el a a |S a rE PS “ye Ev ed ee Ss et Sa Pee ; GSA 87 Mead 2 -o 008 OS OS! ee ES a BEES Sis Bl SESS Sl) es ee Es Sn I Be : SA i Ee EY | | a ee al Re RS po OS EM SS i 9) oe a ee 7 Q ecor 2: Ma (cell i roe per 2 he ieee ae poof SEs Ed ED || Ee a & Sze BN a 2] ie EG aE PS ee oie | Le eS ee ee: A See i ee et fs Sel 7 eee a Se (era ieee ee ae ae Se Oi! cS Se ie oes ae, Na ee, SE ee GS y pees) EE S| ——— HS A PE I) i es ae a Se ee 1 Se ee ee Ses ee . YING OF LARVAE (G3) 220 b. & Re <22E LEA C FRUIT 13TH. INTERING LS bl dae oe ae | m= | LaRUAE ————_—_ Fic. 32.—Seasonal history of the codling moth at Yakima, Wash., 1921. FIRST GENERATION fe BROOD SECOND GENERATION i ee THE CODLING MOTH IN THE YAKIMA VALLEY. 55 VARIATIONS IN THE SEASONAL HISTORY OF THE CODLING MOTH IN THE UPPER AND LOWER YAKIMA VALLEYS. Owing to the fact that the Yakima Valley is divided into two large sections, the upper and the lower valleys, and that the season in the lower valley is somewhat earlier than in the upper, some studies were made by means of banded trees and screen cages to ascertain the ane this difference would have on the seasonal history of the codling moth. In Figure 33 a comparison is made between band records secured in 1919 at Yakima in the upper valley, and at Buena in the lower valley (see also p. 20). The solid line is a record of the occurrence of larve under bands at Yakima, with an elevation of 1,100 feet, and the dotted line records the same thing for Buena, with an elevation of 850 feet, the two stations being approximately 16 miles apart. At Buena the maximum number of first-brood lary occurred July 3, and at Yakima a high point was reached July 17, which, judging from insectary records, probably represents the true maximum more accu- rately than the high point of August 1. Thus there was an interval ee awe eeslelal eka ack el CLEC EE Ee eo ok SS EI eee I eRe e201 RE eee S005 S08 se8e Cees ee eee Sse ENE? bi lal er) Sekine yw tpi in oe eee bi) Er oA aie eae eS SA 2 (Zo COREE ea (SE AD 50 8e aE BEE EOE LPL PARE 2400S Ne AEA 400 valine COTE YORE ART on are POCO ALYCIA NAN Zo eS)E CR Se Ney ern OTT RYT LY eT ESR 4060 S> 46nd eS QHOAVODSYEROVM OAL YN VON SEK OH 0A ~ENOD AR SY YP PSREG ASH EN OMOAN AHS ALES FTA SV VOGT YSUNE SULLY AUG. SLP7, OCT. Fig. 33.—Occurrence of codling moth larve under bands on apple trees at two points in the Yakima Valley, Wash., 1919. of 14 days between the two stations. For the second brood the maximum at Buena occurred August 23. At Yakima the actual maximum occurred September 18, 26 days later, but this was due to an accumulation of larve delayed by cold weather occurring Sep- tember 8 to 13, and it is believed that the true maximum should have been about September 3, or 11 days later than at Buena. In 1920 not enough larve were secured at Buena to show con- clusively when the maximum for the broods occurred, but the ap- arent maximum at Buena occurred several days before that at akima. Temperature records were kept in the orchard at Buena in 1920 and 1921 with a thermograph, and a comparison of these with similar orchard records at Yakima shows that the average monthly tem- perature at Buena is higher than that at Yakima. The average difference in 1920 and 1921 for each month during which records were taken has been figured and was as follows: April, 4.7°; May, 3°; June, 3.1°; July, 2.4°; August, 2.3°; September, 2.4°; the average for the season being 3°. Screen cages containing from 50 to 200 larve were also placed at various points in both valleys in 1920, 1921, and 1922 and examined 56 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. every three days during the time the spring.brood of moths were emerging. These cages were stocked with larve in the fall, the larve being allowed to spin cocoons under a burlap band around a section of a tree limb held upright in the center of the cage. The cages were placed in the crotches of trees in orchards early in March, before any development had taken place. They were thus kept under as nearly normal conditions as possible. The elevation at these stations ranged from 800 to 2,000 feet. These cages differed very little in the time of emergence of moths. At most of the stations the maximum emer- gence occurred within three days of the maximum date at the in- sectary at Yakima. Thus in 1920 the maximum date at Yakima was June 2. Of 13 cages, the maximum emergence occurred in 10 of them during the period from June 1 to June 4, inclusive. Of the other three cages, one was in the lower valley on a south slope, and the maximum occurred May 21, and the other two were at elevations 600 and 1,000 feet higher than Yakima, and the maximum emer- gence occurred on June 8 and June 15, respectively. In 1921 the maximum emergence at the insectary and in a cage in the experi- mental orchard occurred on May 30. In the other nine cages it occurred from three to nine days later. In 1922 maximum emer- gence of moths again occurred at most stations within a few days of the maximum at the insectary at Yakima. The maximum at Yakima was on June 1. In the lower valley two stations were maintained and the maximum occurred at one of them on May 27, and at the other on May 30. In the upper valley the maximum at two stations was May 30; at five, June 2; and at one, with an elevation of 2,000 feet, June 8. This evidence tends to show that there is not very much difference between different parts of the two valleys in the time of emergence of moths of the spring brood, though, owing to the warmer summer weather in the lower valley, the majority of the first brood of larve became full-grown from a week to two weeks earlier than in the upper valley. SEASONAL-HISTORY STUDIES AT WENATCHEE, WASH., 1915 AND 191 During the seasons of 1915 and 1916 the senior author, while sta- tioned in the Wenatchee Valley of Washington, undertook some life- history studies of the codling moth. Since these were carried-on as a minor project, it was not possible to make as detailed studies as have been made at Yakima, but it is deemed advisable to present. here a summary of the data that were obtained in order that a com- parison may be drawn between the two districts. The Wenatchee Valley is situated in central Washington, about 60 miles north of Yakima. The elevation at Wenatchee, which is just south of the confluence of the Wenatchee and Columbia Rivers, is only about 800 feet, but as the valley is nearer the Cascade Moun- tains than the Yakima Valley the season is about the same. The average apple crop in the Wenatchee district is about the same as that of ihe Yara district. The winter of 1914-15 was mild and the spring early. Maximum temperatures of 80° F. or more were experienced on April 16 to 19, inclusive, which is unusual for this month. Warm weather was again experienced during the first week in May, after which temperatures ~ 4 | | THE CODLING MOTH IN THE YAKIMA VALLEY. 57 were somewhat below normal, and the precipitation was relatively heavy. The early part of June was cool, but tke rest of the summer was unusually warm. Of the 72 days in the period from June 21 to August 31, inclusive, 38 days had maximum temperatures of 90° F. or over. ‘The apple trees were in full bloom April 15 to 20. Figure 34 gives a summary of the stages in the life history of the codling moth that were chiefly studied in 1915. The maximum pupation occurred during the warm weather in April and the maxi- mum emergence of spring-brood moths just one month later. Of 144 pupz observed, the average pupal period was 30.44 days. No further studies of the codling moth were made until late in June. Newly hatched larve had been first noted entering the fruit on trees in the laboratory yard on May 29, and on June 27 the mature larvee were beginning to leave the fruit. On this date 226 wormy apples were collected to secure material for further observations. APRIL MAY ASUINE SULY Fhe WLPTEMBER| OCTOBER eC ie | ee | ee eres} OULRTION YF SPRING BROOD /9/6 | 26 TH. g - 48 7H. (hee hl a eek ae” MERBENCE \OF SPRING BROOD MOTHS AS 1915 _|7THeg, 1377 . 2 67) CELLED UNLORE: MERGENCE \OF SPRING BROOD MOTHS /WE IApE THE LZ 78bs | UT, barra puear le RET BRGPD 1915 7 9TH. 49TH. 7] EMERBENCE 0 057 | 2000 MOTHS /U5 13TH, ; ~~ 7 gs) LMERCENCE_ O y< EST BROOD MOTHS 24g (ATH. /H16 Fig. 34.—Partial seasonal history of the codling moth at Wenatchee, Wash., 1915 and 1916. Of the 179 first-brood larve observed, the average cocooning period was 6.82 days. Pupation began July 3, as shown in Figure 34, and continued until August 9, with a maximum on J uly 21. The average pial period of these first-brood individuals was 11.87 days. Moths egan emerging from them on July 13 and continued until August 21, with a maximum on August 1. Larve of the second generation began leaving the fruit on August 24, reached a maximum on September 4, and continued to leave the fruit until October 6. No evidence of a third generation was obtained. In 1916, the season was later than in 1915, but little warm weather being experienced until the second week in June, when it suddenly became hot, temperatures going above 90° F. on June 13 to 17 inclusive, and above 100° F. on the last two days of this period. This hot weather was followed by two weeks of abnormally cool, ~ 58 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. rainy weather. Thereafter the weather was not unusually warm until the last week in August, when temperatures of 100° F. or more were again experienced for five or six days. With a cooler spring, the development of trees was delayed, and apples were not in full bloom until about the beginning of May, nearly two weeks later than in 1915. Figure 34 summarizes the data secured on several of the stages of the codling moth in 1916. Pupation was at a maximum on April 26, and the average length of the pupal stage was 31.29 days. Moths of the spring brood began emerging in the orchards early in May, though none was secured at the insectary from the limited material available until May 20. There was a maximum emergence on May 24, and emergence continued until June 17, though, owing to the cool weather of the latter part of June, a few moths emerged in the orchards as late as July 11. Only general observations were made on oviposition, and this work began late in May and continued as long as moths were present. Larvee of the first brood began leaving the fruit on July 5. On July 11 an examination was made of 687 wormy apples, and it was found that the mature larve had gone from 5.6 per cent of these. The largest number left the fruit on August 3, and larve continued to leave until August 24. The average cocooning period for 493 first-brood larve was 6.42 days. Pupation rnc from July 12 until August 29, with a maximum on July 31, as shown in Figure 34. The average pupal period of 493 first-brood pupz was 13.49 days. Moths of the first brood were emerging from July 24 until Septem- ber 14, and probably later, with a maximum on August 15, and the oviposition followed very closely the emergence of the moths. The maximum hatching of second-brood larve occurred August 15 to 20. It will be seen from this brief summary that the life history of the codling moth in the Wenatchee Valley follows very closely that in the Yakima Valley, but each period would probably occur slightly later in the same year at Wenatchee than at Yakima. MISCELLANEOUS STUDIES. WINTERKILLING OF LARV. It is a common occurrence to find winterkilled codling moth larvee when examining trees in the spring. Some larve appear to succumb to fewer degrees of cold than others, but, as the cold increases, increasing numbers of larve are killed. An opportunity of studying this effect of the cold was afforded in the winter of 1919-1920. In December, 1919, minimum temperatures were experienced in the Yakima Valley lower than any previously recorded. On December 9 and 10, a severe snowstorm occurred, with some wind. The storm cleared away on the 11th, and minimum temperatures of zero or lower were recorded for the four succeeding days. On December 13 the Weather Bureau observer at Yakima reported —24° F. while the minimum thermometer at the insectary recorded —25.5° F. Unofficial reports from various points in the Yakima Valley showed minimum temperatures of —15° to —30° F. During this cold period there were from 4 to 18 inches of snow on the ground, THE CODLING MOTH IN THE YAKIMA VALLEY. 59 After December 15, the weather gradually became warmer, and for a number of days the temperature remained above the freezing oint. All the wintering larvee in the insectary succumbed to this extreme cold. Examinations of larve wintering on apple trees were made in various localities during the succeeding two months in order to ascertain the effect of different degrees of freezing on the larve. It was found that where minimum temperatures of —15° to —20° F. had been experienced from 70 to 80 per cent of the larve were killed. Minimum temperatures of —20° to —25° F. had killed from 80 to 90 per cent of the larve, and minimum temperatures of —25° F. and lower had killed all the larve. In all cases the larvee examined had no other protection than bark or burlap bands. Larve occurring below the snow line of December 13 or in the soil all survived, no frozen individuals being found in these places. These protected individuals made possible the continuance of the codling moth in the colder localities. On January 18 and 19, 1922, the minimum temperature at Yakima was —4° and —8° F., respectively, and on several other days in January the minimum was zero. An examination of wintering larve on the trunks of apple trees near Yakima was made April 17. Of 346 larve examined, 15, or 4.3 per cent, had been frozen. WINTERING PERIOD. During the season of 1920, records were kept of the date of leaving fruit of all wintering larvee, and in the spring of 1921 the dates of pupation of these larvee were recorded. ‘These figures show a wide variation in the length of this period. One lot of 176 larve collected under bands on September 18, 1920, which had all probably left the fruit within a period of three or four days, pupated over a period of 58 days in the spring of 1921, or from ea 10 to June 6, inclusive, as shown in Table 45. The pupal period was more than usually prolonged in 1921, however, owing to fluctuations of temperature. A cold wave in the middle of the pupation period, from April 21 to May 4, delayed the pupation of many larve and resulted in two maximum periods of pupation instead of the usual one (see Fig. 23). On the other hand, there is a definite tendency of the earlier-matur- ing larve to pupate earlier than those maturing later in the fall. The pupation of 49 wintering first-brood larve was recorded, and of these 35, or 71 per cent, pupated during the first half of the pupation period, that is, April 9 to May 5, inclusive. Records were obtained of 499 wintering individuals of the second brood, exclusive of the lot of 176 mentioned above. As shown in Table 46, approximately half of the larve leaving the fruit in August pupated before May 5. Of those maturing in September, about two-thirds pupated before May 5, while of those maturing in October, only one-third pupated before May 5. Zs ae ria an “ae . " < : Gaerr ’, >.« : 2 ‘ " iy . ss are US ay “ i 60 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. TasLe 45.—Wintering period of codling moth larvxe of the second brood collected under bands at Yakima, Wash., September 18, 1920. Winter- | Number Winter- | Number | Winter- | Number Baier ing period] of in- eee Ao ing period] ofin- | baa ing Seat of in- Eade in days |dividuals |) PUP in days |dividuals | PUP® in days {dividuals Ea 1921 1921 | 1921 Apr. 10 204 4 || Apr. 27 221 1 | May 15 239 12 ll 205 5 || May .1 225 i 16 240 6 12 206 3 2 226 1 | 17 241 $ 14 208 1 4 228 Ay | 18 242 4 8s) 209 2 5 229 3 | 19 243 5 16 210 5 6 230 6 20 244 5 17 211 8 7 231 4 | 21 245 2 18 212 8 8 232 5 | 22 246 7 19 213 3 9 233 7 | 23 247 4 20 214 2 10 234 5 | 24 248 3 21 215 7 11 235 5 29 253 1 22 216 3 12 236 8 || June 4 259 2 25 219 3 13 237 5 6 261 1 26 220 2 14 238 12 iA Seen oS 176 Averare number of ‘days in’ wintering period =>. :-. 3.22. . 222... S222 eee es 2 = Be See 229. 79 Maxintum number of days’in wititering period’... .-625: FLL fiert ). els. Sr ee Se 261 Minimum number of days in wintering period 2-2. oes shes seater eo o ceemepeesaesss4-= tase oe ee 204 TasLe 46.—Time of pupation of wintering larve of the second brood of the codling moth, Yakima, Wash., 1921. Date of pupation. : Number : . : April 9 to May 5 May 6 to June 5 Date of leaving frnit. of in- ? , dividual 1921. 1921. Number. | Per cent. | Number. | Per cent. Ree. 6233800 OY DST AGU ay Bi ass 39 18 46 21 54 Te TET, ee a MEET 2 2 ad Pree TEPER 201 135 67 66 33 erent ae ce ee Oo, ee eee ee a 140 92 66 48 34 Getha-as.7. isi orci Seer hermes is 75 26 35 49 65 eee en ae ee ae ee oe ee 44 14 32 30 68 EMERGENCE OF MOTHS FROM THE SOIL. In the Yakima Valley a considerable number of wintering codling- moth larve spin their cocoons in the soil about the bases of the trees. Most of these cocoons are found in the first inch or two of soil and immediately adjacent to the trunk of the tree. (PI. III, fig. 2.) Examinations of trash and soil away from the trunk of the tree have failed to show any appreciable number of cocoons. In the fall of 1921, five unsprayed trees were carefully examined, and 2,780 wintering larvae were collected. Of these, 578, or 21 per cent, were in the soil. On account of the large number of worms cocooning in the soil, it was thought desirable to ascertain what effect this fact has on the emergence of the spring brood of moths. Accordingly, in the fall of 1919, four screen cages were arranged, two of which each had an upright stump with a burlap band around it secured to the floor tosimulate a banded orchard tree. The other two were each equipped with an upright piece of wood in the same position as the stump, Bul. 1235, U. S. Dept. of Agriculture PLATE III ‘J , . PEs 1 Fic. 2.—PUPAL SHELLS PROTRUDING FROM SOIL AT BASE OF APPLE TREE THE CODLING MOTH IN THE YAKIMA VALLEY OF WASHINGTON wee tm”, THE CODLING MOTH IN THE YAKIMA VALLEY. 61 and several inches of soil was placed in them, about the pieces of wood, which latter were too smooth to afiord a cocooning place for the worms above the soil surface (PI. I, fig.2). Each cage was stocked with 160 worms in September, 1919, but the extreme cold in Decem- ber froze those in the band cages and some in the soil cages. Con- sequently, in February, 1920, 100 additional worms were placed in each band cage and 30 in each soil cage. These cages were set in the open, side by side, the soil cages being sunk in the ground so that the soil surface in the cages was level with that outside. Records of the emergence of the moths were made daily, and 60 moths were secured from the two band cages and 134 from the two soil cages. In 1921 the experiment was repeated, 100 worms having been laced in each cage in the fall of 1920. Emergence records were bart as before, 98 moths being secured from each pair of cages. In 1922 records were again obtained, 130 moths being secured from the band cages, and 57 from the soil cages. In Table 47 the records of the emergence of moths from the bands and from the soil are compared for the three years, the dates being iven on which specified percentages of the total moths had emerged. i 1920, moths emerging from the soil appeared from 6 to 13 days later than those from the bands, while in 1921 this interval was only from 1 to 4 days. In 1922 the moths emerged from the soil cages earlier than from the others, for the most part. The reduc- tion of the interval in 1921 was due partly, if not wholly, to a period of unseasonably warm weather occurring from May 13 to June 9, and covering practically the entire emergence period of these moths. In 1922, the weather also was unseasonably warm throughout June. ‘Thermograph records were kept both of soil and of air tem- re and the daily mean soil temperature every year averaged rom 2 to 4° higher than the air temperature. It is evident from these experiments that, although the soil tem- perature averages somewhat warmer than that of the air, the emer- gence of moths from the soil may be somewhat delayed and may be more prolonged than that of moths from the trunks of trees. This ey . even more pronounced in orchards where cover crops shade the soil. TaBLe 47.—Emergence of moths of the spring brood of the codling moth from bands and from the soil, Yakima, Wash., 1920, 1921, 1922. 1920 1921 1922 Per cent Date emerged. | Date emerged. Date emerged. emerged. | nie nel 1 eee From From val. | From From val. From From be 523 bands. soil. _ bands. soil. bands. soil. 62 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. TIME OF DAY MOTHS EMERGE. In order to learn at what time of the day most of the moths emerge, observations were made on moths of both the spring brood and the first brood in 1919 and 1920. Certain lots of pupxe were observed hourly from 6 a. m. to 6 p. m., inclusive, during the time the moths were emerging in quantities, and a record was kept of the number found at each observation. The records for 6 a. m. include all moths emerging between 6 p. m. and 6 a. m. Moths of the spring brood.—In 1919, the hourly emergence of moths was observed from May 21 to June 1, inclusive, as shown in Table 48, 454 moths being beerdudl The largest number for any hour emerged between 9 and 10 a. m., 27.8 per cent of the total being recorded for this hour. TABLE 48.—Hourly emergence of codling moths of the spring brood from 6 a. m. to 6 p. m., inclusive, Yakima, Wash., 1919. Number of moths emerging at— Date of ibm ini wa Detat emergence Az oh. - P.M. tor él of moths. moths Che ol yO} Of S| 981 30) a0} 6 Lb oat soo Wed ee 80 May 22....... vo) ol? sez]. ag bead!) g 10 ha fF ORY DT eas g 78 May 23....... Dt OL EF0 he Ot cadcreshe tha eeorl iba ee 17 May 25....... DT! Gh OPO Oe et Pee ae Tee 37 May 26....... Oo! loolhorokr smtroshbrplaugio ait tilaelsead Vanes 74 May 27....... Ot 0], Sigsiat 1 15| i) 3 Wien. dee tes 73 May 28....... Of 2 ot oF Nee etigg | Chg — aimee Per cent...... | 0.0 0.0 0.0 | 2.1 16.6 | 32.0 16.9118] &S1 6.7| 25) OF) cae . | | THE CODLING MOTH IN THE YAKIMA VALLEY. 63 Moths of the first brood—Hourly emergence of first-brood moths was observed in 1919 from July 21 to 23, inclusive, 138 moths being recorded. Table 50 shows that more moths emerged between 8 and 9 a. m. than during any other hour. TaBLE 50.—Hourly emergence of codling moths of the first brood from 6 a. m. to 6 p. m., inclusive, Yakima, Wash., 1919. Number of moths emerging at— OOS | Total Date of emergence A.M. PIM. pera MME. wins Wile TW} Sint an) iis or moths July 21....... 1 Tp aap) 3 RY ASG ot) feet se ito Ha 59 July 22....... 1 1 G1. 233 |, 13+ ot oe eS Gee ee Oth vy Ola O 50 July 23....... stg hora 5 1 6 1 of OT Oo Total..| 6] 2| 14] 30] 22] 23| 1 Pie a) Og 2 0 1 138 Per cent.....- ee as Ot or7 bing | 16-7 So} RE P1010 | ah ae} 001-07 |e In 1920, observations were made from August 9 to 14, inclusive, Table 51 showing that of 234 moths the largest number emerged between 12 noon and 1 p.m. The emergence period of first-brood moths covers more hours of the day than in the case of the spring brood. In 1919, 64.4 per cent of the moths emerged between 7 a.m.andilla.m. In 1920, the emergence was even more prolonged, and in order to total up a comparable number of moths it is necessary to include all moths emerging between 10 a. m. and 4 p. m., between which hours 67.7 per cent of the moths emerged. In all cases, a majority of the moths emerged before the maximum temperature for the day was reached. TaBLE 51.—Hourly emergence of codling moths of the first brood from 6 a. m. to 6 p. m., inclusive, Yakima, Wash., 1920. | Number of moths emerging at— | pateine oe E ARE Las i i TO et 1 Date of | emergence | A.M. P.M. bavor Seine ere ee Meet 6 2a sp a ed i eh oe Aig 9 (2.3.25 0 0 0 1 1 2 2 11 9 4 3 0 0 33 Aug. 10...... 0 1 1 0 0 0 1 4 6 5 5 9 0 32 BUBGSU - srods 2 0 0 4 1 5 2 6 0 4 1 1 0 26 US be opr atiry 1 0 1 1 0 2 2 7 1 5 4 5 5 34 Vit (yl 1s jee Sapa 3 0 1 2 0 6 2 11 7 6 11 4 7 60 Aug. 14...... 4 1 5 7 6 2 + 9 1 1 0 0 2 49 Total..} 10 2 8 15 8 24 13 48 24 25 24 19 14 234 Per cent...... 4.3} 0.9) 3.4] 6.4] 3.4) 10.3] 5.6] 20.5]10.8| 10.7] 10.3] 81] 5.9 ]....... TIME OF DAY MOTHS OVIPOSIT. It is of some importance to know the time of day most of the codling moth eggs are deposited and the effect of varying degrees of temperature on egg deposition. It is particularly important to know the effect of temperature on the deposition of eggs by 64 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. the spring brood of moths, in order to time properly the first cover application of spray. These points were made the subjects of experiments in 1919 and 1920, both on moths of the spring brood a on those of the first brood, and in 1921 on moths of the first rood. Moths of the spring brood.—In 1919, seven cages of moths, each containing approximately 25 individuals, were observed daily, begin- ning at 6 a. m., and observations were made every three hours, except at 3 a. m., during the period from June 3 to June 8, inclusive. The temperature at the time of making each observation was also noted. The results of these observations are given in Table 52, the number of eggs deposited in all the jars for any given period being added together. No eggs were deposited between midnight and 6 a. m., and thereafter the number increased for each period, reaching a maximum of 57.30 per cent of the total during the 3-hour period ending at 6 p.m. Between 3 p. m. and 9. p. m., 80.67 per cent of the total eggs were deposited. TaBLE 52.—Time of oviposition by codling moths of the spring brood, in 38-hour periods, Yakima, Wash., 1919. — Date of oviposition. 8 * June 3 | June 4 June 5 June 6 June7 | Junes © 3 | _ . i inc Boal ae ee | S| Loe Pn MA bea fs oe lee pee, 3 nn Hour of vs a el os é a fa i oS Observation. |-a-|, dij. bo fh. o.| Bead. Lea loa! eeol a a seth ke = o3 Sead gE IG IPE a pe Uso? 84S Se De eee S) = rs) 2 iS) = 3) = 3) 2 rs) = a 2 7: wy we om be = be ° A st a = i = a Sl =P gd P= ee 2 - Pe Pa +a re Pe Ve pea Se pe ae = < fa Gittins ee 0 61 0 57 0} 60 0 ol 0 49 0 56 0| 453. 83 0. 00 at 1) eee eee 0} 63 0} 67 3 68 0 59 0} 61 0} 66 3 63. 83 0. 67 Snoon He 5. 3 x 72 0} 78 1 79 1 66 0} 67 0 71 9.) T2417 2. 02 Sipe sneaks 24 76 24 81 4 7 0 69 2 71 16 74 7 75.00 15. 73 (ra oni ao Bae es 119 75 66 79 41 70 8| 62 9 66 12} 69 255 | 70.17 57.30 2 ee 10 61 76 66 14 57 0 62 1 57 + 54 104 57. 83 23. 37 12 midnight....} 0 58 0 61 4 56 0 2 0 61 0 4 4 62.00 0. 90 Total..... tee | 166 | as Bz.| sas Balas oy Sa co Re 445 | SSS Ts 8. Total number of OBES ORM LOU 2 Orin esa iis aw wigan eget ore ahr tne anc anirerrararho neers ar atrial Tad arene oe 394 Total nimmper/of eggs ON Capes. - oe nn ba ne nto pew en wep wine ewe Ene nie = ne oe Bs a 51 Per cent oferes on ieliape: bo. 23. 3. Ss. b A ee ee Eo ee . 54 In 1920, five cages of moths were used for observations on the time of oviposition, the results of these observations being pre- sented in Table 53. During the time these moths were under special observation they deposited no eggs between midnight and 9 a. m. Thereafter, the number increased for each succeeding 3-hour period until the period ending 6 p. m., during which 40.92 per cent of the total were deposited. Between 3 p. m. and 9 p. m., 68.97 per cent of all eggs were deposited. THE CODLING MOTH IN THE YAKIMA VALLEY. 65 TABLE 53.—Time of oviposition by codling moths of the spring brood, in 3-hour periods, Yakima, Wash., 1920. Date of oviposition. 3 >) June 19 | June 20 | June 21 | June 25 | June 26 | June 27 5 es ——$————————_ f fs ee — . 3 co a B a a a 2 = y= Hours of ee | 3 S 38 Observation. | & ia} 2) F Swe wes BuSeta | a | 8 : | rs) a o acy ° a} ° ne} to) a] ° p n 2 oa 5 2d RNG at tk Epa "Cake RE Ap ae PR ad aL ah Bb 2 =e ais | ace ca eatarl cena. teecime char [reel = RO ae a. a A, a i Fs * HIST ETS S| Se eS) St BIEL ele) 3] 8 | Z — Za a) A a Z o AlH|A HIi4IH|a4 BH|/4Iiabk# |G a Gq oH HH < = eatin. Pe 0164} 1167] o|60| 0|459| 0|65| 0|456| 0|62 1 | 59.00 | 0.05 eres Yo es OU78 0 | 66 0 69 0 | 68 0 | 67 0) 71 0|7 0 | 69.71 0.00 MTLOOD. «acc ces 0 | 83 217 0|7 26 | 76 0 | 78 579 0 | 88 33. | 79.29 1.61 5 a A pi 90 | 8&8 | 404 | 83 47 | 81! 100] 7 104 | 73 34 | 83 0 | 91 779 | 81.86 | 38.07 Pag. Hs. See sce 341 | 72 | 170 | 77 89 | 7 69 | 66 54 | 69 94 | 81 26 | 90 843 | 76.14 | 41.20 esd st.. sss 36 | 64} 30] 65 48 | 65 6 | 63 1} 62; 89) 69) 157 | 77 | 367 | 66.43 | 17.94 aziat.2) 2... 4|62| o|62| 1/63! o|60| o|69| 3] 67| 15|74| 23] 63.86 | 1.12 Total....| 471 |.-..| 607 |---| 185 |...) 201 |-..-| 159 225 108) |S 2 ) <>) <3) oO oO L-Te) 2 8] O'] & | a-| 2 | 2] 8] 22] 6 }.ar 2] s os 8 : S/EIEVEISIEIE/E/EIE/S/el2]/ 2/5 | a Wek = Nao = ae VA d= pal Dd = et’ ht = fh < a | eM = cist oc 0 7 0 64 0 63 0 68 0 69 0 71 0 67.50 0.00 © i: Oa a 0 77 0} 81 0} 80 0 79 0} 81 2 82 2 80. 00 0.21 22AN00N. =. <2 2 0} 80 2 93 0 $0 6 92 12 95 4 94 24 90. 67 2.54 4 Opedie aes 2 20 | 80 8 94 3 91 4 95 0 99 2) 99 37} 93.00 3.92 @ 1) 0 50 Gee ete 51 82} 101 87 75 85 23 i 35 85 39 86 324 85. 33 34.29 SDs ID aisraics ae 86 71 PHIS2 76 57 68 82 71 | 119 81 36 82 512 74.83 54.18 (wat tik ateu) | O-}, Air eod 3} .72| 1]}.-65| 19| so] a] 7 46 | 73.67 4.87 Total..... | 157 [ete 255 fob 143 138 | ly a 116 [28 1954 fee ole Le wt) ti me. ‘Total number of eggs on Toliagess... £2 Se SRE SAE Sa EPR Ao Ea ee 676 Total numberof eg28\0N Cases... so5 sso. ge.s - Pees Se ererchae oe SS. h ae eee ee Ee = ee 269 Per cent Of Goes On TORO ser we oe a ee wie ae o> ise oo ae alee are che ee ae ee ee Oe eee eee 71.53 In 1921, this study was again made with first-brood moths, five © cages being used. As in 1920, the majority of the eggs, 54.68 per — cent, were deposited between 6 p. m. and 9 p. m., and 89.35 per cent — were deposited between 3 p.m. and 9 p.m. (See Table 56.) ‘ TABLE 56.—Time of oviposition by codling moths of the first brood, in 38-hour periods, Yakima, Wash., 1921. Date of oviposition. A A | Aug. 4 Aug. 5 fee cent Aug. 2 Aug. 3 | Aug. ug. age Hour of observation. oe tem- of oes = | | Pera- | 3-hour Num-| Tem-|Num-| Tem-|Num-| Tem-| Num-} Tem- ture | period. ber of | pera- | ber of} pera- | ber of | pera- } ber of | pera- eggs. | ture. | eggs. | ture. | eggs. | ture. | eggs. | ture. Bid. We de 5 ae 0 68 0 60 0 60 0 56 0| 61.00 0. 00 TR RI I RE” SEs 0 77 0 71 0 69 0 70 0} 71.7 ‘0.00 LAROON. 2.3 50. aco 0 86 0 80 8 80 11 8&2 19 | 82.00 1. 29 Gee PUL a oe ak pin ne sta 0 8&8 13 8&2 78 8&2 3 8&6 94} 84.40 6. 38 HCA. § os ee bh 2 a 199 79 67 77 210 80 35 85 511 | 80.26 34. 67 ON, ON ecules ie bo 310 70 47 66 174 67 275 7 806 | 68.25 54. 68 DAILY, 5 cbiv.nlet os eRe 1 65 2 61 0 61 41 69 44] 64.00 2.98 2 Ofalw <. Kae. 43 GOL |. dita wind A fides ve 470 | Skeet BEG. bien a ce eee Ss Total numberof eggs On folate. o. cia sccc cen decwacencedcncnatnnnaunivnste omedmabaaie: die eee 776 Total number of aes ON CAPES: i. hc ocevenens pec vrun yee cue ese cine ccscbciy pc meen Mlisenn nnn 698 Pet cent of. eggs 00 ToliAge, ..csnccsvenenesusnoucsxstyecnstsyssaseessepssssyehMeeeneeien=nan 52.65 THE CODLING MOTH IN THE YAKIMA VALLEY. 67 These tables show that normally the first brood of moths deposit most of their eggs between 3 a m. and 9 p. m., just as is the case with the spring brood of moths. It will be noted, however, that within this 6-hour period first-brood moths deposit more eggs after 6 p. m. than before, while the reverse is true of the spring brood. This is probably due to the fact that evening temperatures in August are higher than thosein June. The first brood of moths of 1919 were an exception to this apparent rule, depositing more eggs between noon and 3 p. m. than between 6 p. m. and 9 p. m., and the maximum number being found at 6 p. m. instead of at 9 p. m. During the period of observation in 1919 the weather was cooler than usual, and quite windy, at least during the latter part of nearly every day. This possibly caused the moths to oviposit earlier than they would during the normal, hot, nearly windless weather which obtained at the time observations were made in 1920 and 1921. OVIPOSITION BY INDIVIDUAL MOTHS. In order to ascertain the number of eggs deposited by individual female codling moths, freshly emerged moths were paired and each pair placed in a cloth-covered jelly glass, containing moist sand, a sponge saturated in brown sugar solution, and fresh pear leaves, as in the other oviposition experiments. These cages were examined daily, the number of eggs recorded, and fresh leaves and sugar solution supplied. TABLE 57.—Oviposition by individual codling moths of the spring brood, Yakima, Wash., 1919. . 1 | a par \ten r Date of— Number of days—|& 2 = (88 |e ae S53 3 SE | 48 (25 Sa 82 = © |coo |S 15 ae BE a 4 nF 1 1 ty .|® S a Q g 5 = = 3 = Z 2g |B |, |e3ss |Sh lee) galB- |tes S Bas a «6 = B |8Soslne= | EZ loon] SRIAS aS c| 8 | §8 | Be | Sa | os] Se (Sze) BE lage"? lo™ [Ses ra 50 ee) s do O58 BS o.0\55 90'S 9 BS eS suGifos »'A = = O73 S-cltoa:s & TStS) oD 5 |: =| 2 | B? | @ | gg |S |. Bes eas| So SEE/3 [sSSlees Py 2) io =] A ~Q e) ie 4 & Z & < = Days. Days le Gay A 20h ebeee fc eek iy PUIG Pes edeS . Sees seceded 14 sce 2 Qe 323 eee 2 Oss May 24] May 24}June 7 4 1 + 14 18 1 Ueto, 1 ) : May 21 | May 31 | June 21 ae 23 10 22 31 2 33 10 ie 8.6] 38 REL OLD cetera he a | eee Alaa TING Pals tee she oe (eee eens Sis pecs) Or be eee | 1 SRG se el RB eke DF eae FIO Galen eee eS aE a LON eee ae OT (a | fs Be Gi}5~-d022:-- May 24} June 2/|June 4 3 10 12 | 2 14 2 4} 2.0 3 7 SOO ee me ost. LEAVE ACS. SSRN 1 2 Eee (ee ae BO ee Gh seee 0) 5.2 Sect Tie oo ance 2 aaa en Sp fos fe Pe Ca hae: ry eee ON peda. (v= iS Coats cee tl ae, te LV Ea ga) ie oo ee TS Fg Rep nes Oe [has Oa eM cin Dea cr las Sek svat 62 ca hs AR es dl ee 1d Aa ee 2 hy ee ae Lees < es ae June 4{ June 11 | June 12 11 | 8 18 | 1 19 5 3 2.6 | 7 NAS RS Te NS PIV fro dV, eo te eee en he a > 5 | eee ae be ae 3 ab Spe arg ae ek ra ee 2 WO oh Fe On leet Se Pe a Ve ee Oe (ae ae ae te 14 dos. : June 1{|June 7 | June 10 8 (! 14 3) 17 4 BS) RES 4 15 gon.2.* May 31} June 14 () 7 15 A se 8 26 | 3.3 8 16 dont: June 2]June 7 | June 14 9 6 14 7 21 5 26. os 25 be te re May aa Wee Voy see June 2/June 6 8 1 8 4 12 1 x 1.0 1 Opa, | ae Se alae (rea es DIO PSHE oe eo oc cc loeseeeteen oan 141. Se (OU, sae ee 19 G0i.:-< June 13 | June 13 | June 14 19 | 1 19 1 20 1 3 3.0 3 20 oc) Re ARO Cee i ae ee pba acy PA | 2 SR ice oot el kc) | Sale a we 0. See eee 21 Get Che Soo ed, Ces ot Ls June 10M 4: AG PES |S eT Ts | Ae 16"]-0. 9: ti (re a ee ee | 1 Date of death unknown. 68 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. TABLE 57.—Oviposition by individual codling moths of the spring brood, Yakima, Wash., 1919—Continued. SUMMARY. Maxi- Mini- Average.| mum. mum. mtrier Ul. GHYVS DELOre UVIPUSiuIOn=. oo tse on erotics ia tee eee 8. 78 19 3 Number of days from emergence to last oviposition ..............-..-..--- 15. 67 31 4 Nimiberor Ga ys'OL OVI POSItION . 2. Wo: a. poe eee ee eee econ meee 7. 89 22 1 Number of days on which oviposition occurred...............2....-..----- 4.11 10 1 Number of days female moth lived after last oviposition .................. 4. 25 14 1 MOLL enEuMNOL ile OLfeInalo MOLD. OSYS-ce6— nas eee ee ee ene 16.35 33 3 Number of eggs deposited by one female moth.................2-2.2.-...-.- 8. 24 86 0 Number of eggs deposited by one female moth in one day............-..-- 4.68 38 0 Moths of the spring brood, 1919.—Twenty-one pairs of spring-brood moths were segregated in 1919, and the results are given in Table 57. The average length of life of the females was 16.35 days, as compared a with 16.91 for females confined in battery-jar cages (see Table 4). — The average number of eggs per female in the individual jars was 8.24, while 300 females in the larger cages ayer ee only 6.36 eggs (see Table 3). The periods in the hfe of the mot s in this table are not comparable with those of Table 3, which gives the data for all moths in each eage rather than for each individual moth. The largest number of eggs deposited by a female in one day was 388 and during her life 86. No satisfactory oviposition records for individual moths were obtained in 1920. Moths of the spring brood, 1921.—In 1921, six pairs of spring- brood moths were segregated on May 29 and ih 31 each, as shown in Table 58. A comparison with Table 35 show the average length of life of 723 females confined in battery jar cages to be 13.85 days, while the average life of 12 females confined in pairs was 14.75 days. These females laid 288 eggs, an average of 24. The female of pair No. 2 deposited 94 eges, 47 of them being the maxi- mum daily oviposition for a single female. The average egg deposi- tion for the two years was 13.97 eggs per female. TaBLE 58.—Oviposition by individual codling moths of the spring brood, Yakima, Wash., 1921. . ! >) re Date of— Number of days— ee = 188 iS SOF | 483 128 =| BS ' ' re | +> . o° ma ae x B Z “Gd |8 | |S8siee |SR Ite. 2 ee a, eS = 2 lksslee bee [ood : =| o§ Eq og Og | ad |PSgil® .| $5 noe ~~ e = oso sles 2 Silage 28 ode A 2 iad 3 Se 25 SB ls@Shitss| «4 lGae by o A ~ i oa | ASeless| sa gS ‘2 5 & g $5 |s* | |Peo/sha So [ses - 5 Fy 4 A QA |}o fe B 14 Days .| Days | 1} May 29] June 5 | June 17| June 23 7 13 19 6 25 7 2/...do....| June 1] June 9] June 16 3 9 11 7 18 8 3 |...do....| May 31 do.....| June 14 2 10 11 5 16 8 4/...do....| June 2] June 11] June 12 4 10 13 1 14 9 5 |...do....| June 7] June 22| June 23 9 16 24 1 25 3 | 6 |...do...:) June’ 3 | June) 3. | June. Ll 5 1 5 8 13 1 7| May 31/| June 6] June 6 |...do..... 6 1 6 5 11 1 | gs Fr PCR June 8]|]June 8 | June 10 8 1 8 2 10 1 1M FESR «Fs Pt Se) (AW ea ST | (Ah Ey fou le (Fgh 1 [SORE | pope ees PERS RS Mi hs Rearr aes Lh ee Pe June 4|June 8 | June 12 4 5 8 4 12 2 PE Ne lO indy slo wae ou ke rel emeree se toe Tye vats fe Oh ates Bids) RR eo) PRR] [ai Witte sos June 3]June 8] June 17 3 6 8 | 9 L7 5 | 12 ee | | of number eggs. ———— | —— | | — — — | | S.4, [Bo ate ss ‘i we foe Bo 88 : ge ae. aa RS gee ; jor sw 7] So jeeel © eoglaes) PosliacS| # a edt = Og |] aq Pegio D4! Sis Ba e| FO lo 15 obo a be a 9.8 ip O-m ae 8 Blao8 i) ao8 Bo gj Hos i 5 a ae se | Se] O° |Eacipes| So (gesis jS8sleW ‘a | a re 2 9 @ |. |e olga] 66 |SEol/S |rosiaod 5 & = a 2 1O & 4 H |4 xe | /|& Days.|\Days Lyrae hes gl i alee (ag ca le fe SDN Tg APR eda Ai | Sati in | flee lea Mi 1 een GS iee one of 12s. G05 442 July 25) Aug. 7;Au 8 2 14 15 1 16 ll 91; 8.3] 18 cE ae eee Aug. 2|Aug. 6|/Aug. 6] 10 5| 14 0; 14 Sli. doa ees | AN asdoi. 2 July 25} Aug. 2}Aug. 3 2 9 10 1 11 7 18} 2.6 4 he aeria sO. - GL Oe eo .6.j:Auge 17, 2 13 14 1 15 8 PARE at 8 | 6|..-do.....)Aug. 6]Aug. 10|Aug. 11] 14| 5{| is] 1] 19] 5] 36] 7.2] 28 | 71 July 25 |...do..... Aug. 6|Aug. 7] 12 Billy 12 bly 1 Libt LO as ea SCO July -27 |.--do.....|..-do..... 2 il 12 1 13 2 Sil hae 2 ed ae Ce July 30{|Aug. 9} Aug. 11 5 11 15 2 17 3 14] 4.7 8 10}) 8.0) .- 5 Aug. 5| Aug. 12} Aug. 13 11 8 18 1 19 3 Pi be elo 2 ea ae AM Praveen sn A SUr fay GAG) (ae | eA ad pa belie LA Uy) ki, 20 9 OU ee eee 12 |...do...-| July 31} Aug. 9 | Aug. 13 MITT 10 [S113 4) i 3] 14} 4. 7a) ge Pear te ce anne See oe ATE LO VS See a ee, Pe thes Le [eee eee Ol pceuee een tat labe UAES S Setae go Pare Aug? 121.20 5/0. SPN De oS af td Be ee 6 (Vie: meh x 15 |..-do..-.| July 30 | Aug. 14] Aug. 22 3 16 18 8 26 9 29! - 3.2 7 16 |...do...-| July 29| Aug. 4] Aug. 6 2 7 8 2 10 3 ate nw 3 nL LE ES STs ss 55 at Aste DASE eek. Salt REET ee 2 HO) 2h 8 Otek st A-ae 18 |...do....| July 29} Aug. 5] Aug. 6 1 8 8 1 9 Sub? 102) 12. 8°) a7 19'/...d0.2 7.) Aug. 1} Aug: 10] Aug. 12 4 10 13 2 10 6 | 107 17.8 | 44 | 20|...do..-..| July 29 | July 29 |...do... 1 1 1 14 15 di. Init 150 1 Fer teda sr do....| Aug. 11 |..-do EP Tepe tate ee ts | 6 oo eae eee | 22 -d0....| July 30] July 31) Aug. 10 2 2 3 10 13 2 82} 41.0) 78 23 | July 29 ug. 1} Aug. 8 | Aug. 18 3 8 10 10 20 3 16° |, oso te “no LS (om Oe ang aed PN BE Ea | oc ee ON A oven Perea 25 |..-do....| July 30} Aug. 13 | Aug. 15 1 15 15 2 17 7 81) 11.6) 24 Pi wl eget o 0 a Ie 0. Aug. 8} Aug. 17 1 10 10 9 19 3 4} 1.3 2 27 |.--do....| Aug. 11} Aug. 16| Aug. 16 13 6 18 0 18 2 4] 2.0 3 28 -do...-| July 30} Aug. 6] Aug. 17 1 8 8 11 19 8 | 133 | 16.6.| 38 29} Aug. 3] Aug. 8} Aug. 15] Aug. 18 5 8 12 3 15 3 6] 2.0 3 ST) pee RS [ae nr a | Cee Se ICE Pe _ Te tee a Peet BOA tates OS: = 2. ck ee 31 |...do....| Aug. 22| Aug. 24] Aug. 30] 19 87 2h Olea say 2S CSHN I. Se 32 |...do....] Aug. 7] Aug. 16] Aug. 17 4} 10 a 1| A, 9} 173] 19.2] 71 70 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. TABLE 59.—Oviposition by individual codling moths of the first brood, Yakima, Wash., 1919—Continued. SUMMARY. : Maxi- Mini- BVEERES: um. num. Number of days before oviposition..............--.-..22..2-----2---2--+-- 5. 00 i9 1 Number of days from emergence to last oviposition............-.......-.- 12. 52 21 1 Namber ofdays of ovignaitaon .. _ - ==. os ne. 8 nnn a = oe bee eases 8. 52 16 1 Number of days on which oviposition occurred ......-...-.....-------.-.- 4.72 ii 1 Number of days female moth lived after last oviposition .................. 4. 04 14 0 Totallength oflife offemale mothin days...............-..----..--.-.--- 15. 24 27 8 Number of eggs deposited by one female moth...................---..-.-. 29. 94 173 0 Number of eggs deposited by one female moth in one day........-........ 8.37 78 0 HATCHING OF THE EGG. When the larva is ready to leave the egg it moves its head back _ and forth as if to stretch the eggshell. The mandibles are moved — about rapidly until the point of one of them is forced through the chorion, always at some place on the periphery of the egg. An opening the size of the head is soon made in the eggshell and the larva crawls quickly out. Occasionally, a larva has been observed to kill itself in an effort to emerge from the egg by projecting the anal end first through a hole smaller than its Aah DATE OF HATCHING OF LARV. Since the time when the first, the last, and the maximum number of larve of each brood of the codling moth hatch and enter the fruit is the most important phase of the life-history studies in their practical application to control measures, a comparative diagram of the hatching during 1919, 1920, and 1921 is given in Figure 35. It will be noticed that the hatching curves for the first brood are entirely unlike, and that the first larve in 1919 hatched 5 days later than the first larve in 1921, and the first in 1920, 6 days later than the first in 1919. The maximum hatching in 1921 occurred only © 7 days after the first hatching, and this was 10 days earlier than the date of maximum hatching in 1919, and 20 days before that of 1920. The hatching curves of the second brood are much more alike than those of the first brood, and the dates of the first and maxi- mum hatching are nearly the same.. It will be noticed that the dates of the first hatching in 1919 and 1921 are identical, and that for 1920 is 11 days later. The date of maximum hatching in 1920 is also identical with that in 1921, in spite of the difference of 11 days in the date of hatching of the first larvee, and the date of maxi- mum hatching of second-brood larve in 1919 is but 5 days earlier. Figure 35 shows the necessity of accurate life-history data wherever efficient and economical control is to be obtained. HABITS OF NEWLY-HATCHED LARV. Directly upon emerging from the egg the young larve seek food, which in, the case of the codling moth is preferably the fruit of the apple or pear. Occasionally they will burrow into the veins and stems of leaves, and even into the terminal twigs (as shown in Pl. Ill, fig. 1). However, of about 250 newly-hatched larve which THE CODLING MOTH IN THE YAKIMA VALLEY. 71 were placed on the terminal twigs of a small apple tree, only two developed to half their normal size before they died. Before attacking the fruit, the larva will crawl about for several minutes seeking a suitable place to enter. It prefers the calyx cup, stem cavity, or an injury to the skin, as these places afford pro- tection and ease of entrance. When beginning to feed, the larva removes the pubescence on the surface of the apple and cuts into the skin, using its mandibles with a circular motion of the head similar to the action of an auger. The greater part of the skin which is cut away is piled beside the hole, though a little is eaten. Larve entering apples dipped in a red stain showed the stained articles very clearly intheir digestive systems soon after feeding egan. When a hole the size of the head is cut through the skin, SUNE SUL AUCUST SEPTEMBER OCTOBER nN DOAVLRS FNL Oq_VOSVSF HRmH oO AVIV VT FAH oO AVOLVS TA KH OaxVVw ; PTOOD 287H, Fig. 35.—Time of hatching of codling moth larve, Yakima, Wash. the larva excavates a cell large enough to contain its body, and enters, at the same time pulling over the entrance of the burrow the frass which it has laid aside and held in place with silk. This process requires about 14 hours. PERCENTAGE OF TRANSFORMING AND WINTERING LARVA. In Table 60, it is shown that 84.97 per cent of the first brood of larve transformed the same season in 1919, 76.80 per cent in 1920, and 82.78 per cent in 1921. In both 1919 and 1921, 6 larve of the second brood transformed the same year, being 1.42 per cent and 1.02 per cent, respectively, of the total larve, while in 1920 only one second-brood larva, 0.21 per cent of the: total, transformed. In 1919, 15.03 per cent of the first brood of larvee did not. transform until the following spring, in 1920 the percentage was 23.20, and in 1921 it was 17.22. Practically all of the second brood of larve pass the winter in cocoons, the percentages being 98.58 in 1919, 99.79 in 1920, and 98.98 in 1921. a2 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. TaBLe 60.—Percentage of transforming and wintering codling moth larve, Yakima, Wash., 1919, 1920, and 1921. Number oflarve— Per cent Per cent Year. Brood. trans- winter- Leaving Trans- Winter- forming ing fruit. forming. ing. fie a a a ee 1919 Secor ces cere. J 173 147 84. 97 15. 03 Second. -...... 423 6 417 1.42 98. 58 1920 | A Cal 52] es 2 eS 306 235 71 76. 80 23. 20 hSecone.tte.' 2. 485 484 ak 99.79 1921 (Biss ic or © | 662 | 548 114 | 82. 78 17. 22 | Second........ | 589 6 583 1.02 98. 98 NATURAL ENEMIES OF THE CODLING MOTH. Natural enemies of the codling moth are conspicuously absent in the Yakima Valley. While collecting larve from bands, evidences of attack by predacious insects were occasionally observed, and carabid beetles were numerous about the trees, but no beetles were noticed in the act of killing larve. In October, 1919, at Buena, Wash., a small number of codling-moth eggs on harvested apples were found to be infested with a parasite, which upon emergence proved to be Trichogramma minutum Riley. This is the only instance of parasitism observed in these studies. In 1914, at Wenatchee, Wash., the senior author collected from cocoons of the coding moth a specimen of an ichneumonid parasite, which was determined by R. A. Cushman, of the Bureau of Entomol- ogy, to be Aenoplex DRI Cush. In 1916, at Wenatchee, two specimens of Aenoplex_plesiotypus and one specimen of another ichneumonid parasite, Epiurus zndagator Walsh, also determined by R. = Cushman, were reared from codling-moth cocoons by the senior author. Because of the absence of natural enemies of the coding moth in the Yakima Valley, several hundred codling-moth larve parasitized by Ascogaster carpocapsae Vier. and Bassus carpocapsae Cush. were sent to this laboratory from Dover, Del., by E. R. Selkregg, from Cornelia, Ga., by E. R. Van Leeuwen, and from Sandusky, Ohio, by G. A. Runner, all of the Bureau of Entomology. Many of these succumbed during the extreme cold of December, 1919, and no results were obtained the following year. In 1921 a large number of these parasites were reared and liberated, and evidences of para- sitism were observed in several codling-moth larvee collected under bands in August and September. In June, 1922, two specimens of Bassus carpocapsae were reared from this material, showing that this species is becoming established. These attempts to introduce hymenopterous parasites of the codling moth will be continued. REVIEW OF SEASONAL HISTORY OF THE CODLING MOTH IN 1919, 1920, AND 1921. The seasonal history of the codling moth in the Yakima Valley for 1919, 1920, and 1921 is given graphically in Figures 11, 22, and 32. Kach curve shows approximately the occurrence of one stage in the development of the insect. A comparison of the seasonal history for the three seasons is given in Table 61. THE CODLING MOTH IN THE YAKIMA VALLEY, 73 TaBLeE 61.—Comparison of seasonal history of the codling moth, Yakima, Wash., 1919, 1920, and 1921. Stage and year. ‘ Maxi- First acer Last Pupation of spring brood: TE haps Sin Se” Pie Ba ee A Hoek ge, 2S ae a Ge ed eles CS Bl Apr. 8} Apr. 27} May 26 ZO woe IT I PEE eS oe ee ene ie eae ac ee eae Selene oo Apr. 3] Apr. 26 | May 17 1 7A beh eee Set <5 So ene Se eee ik Rees tie meena Sede toe: ean Shy Apr. 9j| Apr. 17 | June 6 Emergence of spring-brood moths: eee eee ee ee ead awe oe ne eae Sone nt Loca Sees st Re May 13] May 21 | June 19 ISL ed Se RU mae REE RUS ae ere een Cee sen A Sen le EE ms May 10| June 2/|July 2 LRA ES ety SESE EEE - 9 BEE Bie EREeL 8 A tne, ee Ree oe 2 ree ee May 19 | May 30] June 27 Deposition of first-brood eggs: BONG saree crerarc ta aio ae a Sap tet oe a a era ak oe i ee eae cp, ae May 21 | June 4 {| June 24 TOD ee tne te. Sees se dee Stor oes doa aah ie an te eae tee gece May 12} June 18 | July 11 TPA LS ROO RIN lal ee See Sree acne) Ee need Seem Sie aera Si May 23/June 41] June 30 Hatching of first-brood eggs: LTRS ete gael sO anita eye Selig ak eyelet Benassy teks Connie Menai) ate Lame hale June 7/ June 18} June 29 cee ER a 8 2d Lhe) ee ee A ee SL 2 Se ES ee | June 12 | June 28 | July 14 UP io sora 8 See Esc mC GES UD CECE SUOCOS OH HES Sa abe BEE CARE Hee ae arya June 2} June 8} July 10 First-brood larve leaving fruit: AS) eStats AA Pee SA SAE SER 5o te Sts See SEI SESS. 2 OOS June 23 | July 12] July 31 bi | Me Rae oO ee oes See | Bee Oe nee fear ee Sea, ee July 6} July 18] Aug. 16 G2 ee eee aes ne cine mses tater sap eaweas estan ese See June 22} July 14j Aug. 3 Pupation of first-brood larve: eet eee) es er A as a a cabin ode e ease ss ct ass July 7] July 19} Aug. 12 Oe ee oa An a Bic A ae Me Me ee July 10} July 17} Aug. 15 Oe ee ae eee ee es ha che the ee CY Ss be on be ek the July 5] July 23} Aug. 15 Emergence of first-brood moths pT OS ee a iy 2 ee ee ee a eee ALE PA ee July 8| July 19 | Sept. 24 ee ee Ye Sh rid. Se ee win os os as iamm a = July 23 | Aug. 15 | Sept. 30 POD Eee ere. ae Pere ee eee eee Se pe Ptowiae ee a ce we cae oe ences odeatee July 13 | July 31] Oct. 9 Deposition of second-brood eggs 1 NOTE Bi se I ct be i ee Se Fhe pak ep a a eae it et a a a July 15 | July 29 | Sept. 20 OD he ed enc Nt A ands 2 ttercls Sb etal StS See wees se eee ees July 27} Aug. 7] Oct. 10 PAD De eo ae 2 Se ey eee a ee a July 15| Aug. 7 | Oct. 13 Hatching of second-brood eggs: Ripe en ee Se Lock ns se Rr vs nr nt on xe 2c yh sags cen xR Ms July 22] Aug. 7| Sept. 27 UNpile cee 5 ibe Se Sed aed sgh oc ee beds soto Sob ceee eeenenctcnonebatcoss Aug. 2) Aug. 12| Oct. 13 NOt eae a ei ae ee Eee. FS SEIT SED Pose oe KS tS ah thes hae s fo July 22 | Aug. 12} Oct. 2 Second-brood larve leaving fruit: EE Ree rae Paar Tama aetna. WS RS e oe SAREE SASL HES BEEBE Geese 50 Aug. 13 | Sept. 3} Oct. 28 TUE TS oe be eS eS Ss Oe tse ee ee Re ne Steerer Aug. 19| Sept. 4| Nov. 2 ie ie oes Seeeei fae sos dos Sect coer coboast be eete Shee Leck ooagtins Aug. 10 | Sept. 5 | Nov. 13 SUMMARY. The seasonal-history studies recorded in this bulletin were made in the Yakima Valley of Washington during the years 1919, 1920, and 1921. The codling moth, while not as serious a pest in Washington as it is in some other States, is the most serious and widespread insect pest with which the Washington apple growers have to deal. The climatic conditions are such that two practically complete genera- tions occur, with a very small third generation in some seasons, as evidenced by the data herein. A comparative summary of the length of the various periods in the life cycle of the codling’ moth at Yakima in 1919, 1920, and 1921, is given in Table 62. The figures in this table are taken from the individual tables and not from the combined life-cycle tables for each year. - 74 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. TABLE 62.—Summary of the average length of the different periods in the life cycle of the codling moth, Yakima, Wash., 1919, 1920, 1921. Spring brood, First generation. Second generation. a Feed- Pre Pre- ing in Pu- | ovi- | ™@lFeea-| © | Pu Bee | COS ene a al |posi-] P@ | ing |©°2"| pal | posi- riod jcoon-| a1 | riod Season. Et tion Seaing |e. 1B tion |(trans-| ing | P Aah pe- | tion pe pe- | pe- pe- | tion form-| pe- pe- | (win- riod a riod, | 04:'] rioa, | Tod rod ing riod. | 10d. eee tr re)3 Days. |Days. \Days. |Days. |Daus. Days. Days: Days. |Days.| Days.| Days. |Days. | Days. NOOR ee Oe es 31.63} 5.53) 12.73} 23.82) 6.99) 13.91) 1.63) 58.42) 8.72} 21.80) 7.20) 16.00} 34.51 THY ticket Marl Sh ocomaepblle Bo. DON 20287101 02601 19-05). 5.48) B2sa21) 2:93) BS ObR 8) 74ic 2 aaa alee ee ee 35. 30 tA bee SI nelle 29.53) 2.47) 9.31] 25.83} 6.12] 12.62] 1.74] 55.88} 7.70} 16.60) 2.50) 17.67] 34.02 ee | eee | ee | ee | ee | ee fae | ee | en lee | Ss lS Grand average. -.| 31.57] 4.96] 10.88] 22.90} 6.20) 12.97; 2.10) 54.10] 8.39] 19.20) 4.85) 16.84] 34.61 1 Stock-jar method. The various phases in the life of the adult codling moths for the three seasons are compared in Table 63. TaBLE 63.—Summary of the phases in the life of the adult codling moth, Yakima, Wash., 1919-1921. e Phase and year. Minimum.}| Average. | Maximum. Number of days before oviposition by spring-brood moths: O19. 2 Bane dhe saiee v. oSeos Cees ooo. Ses ates aea sk cease ee ae 1 5. 53 18 1990 oe Pil n Slap he ls oS < wloniate hee SINS aiciele weenie tstatal aim aie eee sla oe eee 1 6. 83 22 NO 2I et He aah a eaten aoira® ote icicine THE CODLING MOTH IN THE YAKIMA VALLEY. 75 TaBLE 63.—Summary of the phases in the life of the adult codling moth, Yakima, Wash., 1919-1921—Continued. Phase and year. Minimum.| Average. |Maximum. Eee Aa Bas ge Nae b ace cet gd 9 2- Ehigcp y3 Beye 1 23. 39 173 CUA Rees Pere Saat eave a ake Cralaimin Gi cisie ettiene ale Ata crate a NS ea eee ee i ae Pets em i sac Q1-96;'|'-..2- eres TAT?2A Vege ge OR SR ge TE ee eS ie te ee eS Se Se a ee 74) IN 1 Be eS Length of life of male moths of the first brood: HGIGD. APS ISDELS. BASTAASAN ee 48 ECE SUEDE AOD A Dae 2 13. 97 45 1h GoE eae ta eO Sae ae OAe eo he Pr ee Oe ae ee oe ee ee 2 13. 87 34 RPA te ey eee ee ee PE eS ae eS cae dnateorae aepicinuee 50 ain 1 ih yp 39 Length of life of female moths of the first brood: [LETT ae elie, ES aaa re IS oe aiastne nice eM | 1 13. 08 37 IZ Foe ta aa tan eee ue ile steele Pree se os cette Pee. Sites. sees 1 13. 24 {0 1 11.39 50 Studies of certain phases of the seasonal history of the codling moth in the upper and lower Yakima Valleys indicate that the spring brood of moths appears in both valleys at about the same time, but that the majority of the mature larve of the first brood ae ebyine the apples from a week to two weeks earlier in the lower valley. Incomplete seasonal history data recorded at Wenatchee, Wash.., in 1915 and 1916 indicate that the life cycle of the codling moth is approximately the same at Wenatchee as at Yakima. winter temperature of —25° F. or colder may kill all the codling moth larve above snow line, a temperature of —20° to —25° F. may kill 80 to 90 per cent of the larve, a temperature of —15° to —20° F. may kill 70 to 80 per cent, while a temperature of only —7° or —8° F. kills only about 4 per cent of the wintering larve. Moths of the spring brood emerging from cocoons spun in the soil may appear from 1 to 9 days later than those from cocoons above ground, although in 1922 they appeared earlier on the average. Most of the moths of the spring brood emerge in the morning, two-thirds of them appearing between 9 a. m. and noon. Moths of the first brood emerge over a longer period of the day, but the majority of them appear before the maximum temperature for the day is reached. Female moths of the spring brood deposit 65 to 80 per cent of their eges between the hours of 3 p. m. and 9 p. m., most of these being deposited before 6 p. m. Very few eggs are deposited unless the temperature is 60° F. or higher. Female moths of the first brood also deposit a great majority of their eggs between 3 p.m. and 9p. m., but owing to the higher temperatures most of these eggs are deposited after 6 p. m. From oviposition records obtained from individual female moths of the spring brood it appears that the moths may lay as many as 94 eggs, while others will lay none, the average being 14. Moths of the first brood deposit twice as many eggs, the number ranging from none to 173, with an average of 30. The codling moth larva emerges from the egg through an opening made in the periphery, never thiough the portion of the eggshell adhering to the fruit or leaf. : The date of hatching of the earliest larvee of the first brood varied as much as 11 days in the three years the codling moth was under 76 BULLETIN 1235, U. S. DEPARTMENT OF AGRICULTURE. observation in the Yakima Valley, and the date of maximum hatching varied 20 days. The date of earliest hatching of the second brood of larvee also varied 11 days, while the date of maximum hatching varied only 5 days. Newly hatched larve, after finding an apple or pear, will crawl about over it for some time before entering it. It requires an hour or more for the larva to hide itself in the fruit, and most of the skin is bitten off in small pieces and not eaten. If a larva fails to find a fruit, it may burrow into the midrib of a leaf or a terminal shoot, but it appears to be unable to maintain itself on this food. From 75 to 85 per cent of the first brood of larve, and from less than 1 per cent to nearly 2 per cent of the second brood of larve trans- form the same season, the others waiting until the following year. The egg parasite Trichogramma minutum Riley has been observed in the Yakima Valley, and the larval parasites Aenoplex plesiotypus Cush. and Epiurus indagator Walsh were observed at Wenatchee. Occasional evidence of predators was observed. 4 ORGANIZATION OF THE UNITED STATES DEPARTMENT OF AGRICULTURE. August 14, 1924. MCOrClan py OF UA OTICUMNUTE. | 2 Henry C. WALLACE. ALINGOSTIVY (UGS ler C1 Tay Ue ci rr Howarp M. Gore. PIORECIOP Of SCLENIDIGMW ONit-.—. .- =... =~ EK. D. Bau. Derecior of leguiatory Woark..........-.-_- Water G. CAMPBELL. Director of Biatension. Work... __-- C. W. WARBURTON. (OMS GRID Sos eS ES eee R. W. WILLIAMS. VP COCLA OES ONT AREAS sg a CuHarLEs F. Marvin, Chief. Bureau of Agricultural Economics_______ ~~~ Henry C. Taytor, Chief. burca of Animal Industry 2 JoHN R. Mouumr, Chief. ECG OF elm PRaUsiry.: Wituiam A. Taytor, Chief. POGeSTISCOTCe = emmmmtis 62 V. B. GREELEY, Chief. Bureau of CREMisityewe 2 C. A. Browne, Chief. Ea eU OTS OFES eure Mitton WHITNEY, Chief. Boreas Gp Pmtomealagyacs. = Se L. O. Howarp, Chief. Bureau of Biological Survey______-_-_---- E. W. Netson, Chief. Bureau of Publigemoads= == 20 28 2 ee nA Tuomas H. MacDonaxp, Chief. Bureau of Home Economics_________--_--- LovisE STANLEY, Chief. bureau of Dawmyingaee 2 Pastel ee gn C. W. Larson, Chief. Office of Experiment Stations____--_____--- HK. W. Auuen, Chief. Fixed Nitrogen Research Laboratory - ------- F. G. Corrre tu, Director. EMEOLTEGUUIUS 4 Pearman L. J. Haynuzs, in Charge. LUATF Ops) jaa Saag ole. DS rr CLARIBEL R. BARNETT, Librarian. Pederal-Horticuiural poard____-_--_.-___- C. L. Maruatt, Chairman. Insecticide and Fungicide Board _-_.---_-_----- J. K. Haywoop, Chairman. Packers and Stockyards Administration ____- CuEesTeER Morritu, Assistant to the Grain Futures Administration_____----_--- Secretary. This bulletin is a contribution from Bureau of Entomology---------- ets MOS ED IED L. O. Howarp, Chief. Deciduous Fruit-Insect Investigations___ A. L. QUAINTANCE, Entomologist in Charge. 77 ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 15 CENTS PER COPY \ V ri fe Ts ae b. ent vi, ave ‘ a 0s Gh, the YT 40. #oitixtHa owe . i 1A iy ARR STA aR anni anaes 7. eee wet area, > val irom bee ¥ Oe. ve fa ver Ww sertiarsitale Aocaprabesgees ; irvine? Saxo AL siatinoraey Api ag) ieustt wrngheyy Re qcthimah 4 HY nornateA, Yo tokio 5 Nala in _. 2 - wobto riots: rest ah sedan WE | ‘ sissies. Yorn ; -wiaubwe) dogma A Wo wag a Eh : debe. bel Yo apart : RYpactot ca cs ae i TIBLOS \ 4 At) oer >, | eA anaes ints Gh st cold \o yore u% Inotgolosel \a abate dinodth seid Yo abooteth — sutortoo afta th Yo yA 2 “ee tod to wee sat Santi eaerene ASR Aside 5 seoqoysl 5 pat uatou inaldat | , ye re ripe \o-nthirartes dk Taersho W 4) Tarot A. Soeephowi parr : tw Rooks heb odant | bh svat pe Se ut lament oe (ee — at se cLjaey + eronbineth aoe ak % A