titi Pitt et. 2 n a ee eee > =< pte erties meaimintit itah cag AO AOE AIL PELL ALAA LIAL ELLA ALA Lo re sroa : ee a ei ee ee) ie ee ee cel tt isi lh la LS at Sl AE ORL A AG lata el, eh OI i RE a “com epee ae ean carne, nat ents earn aan ie AOA ar eee = Sg ati i,m nein eae tO lag tities = ttn at nett me te Ae Ot A © apc i ag en Ee a ek SR et OE LP ATM Ei eA te pase Prey tit it indir cnt Mls mt sri dein AR SA PRP AP Ne So 8 PES ME a es — ni eget = re On ia ena Ae oe me Pre emt Nr ate pert A ee EEL LOGO LL AL LE LEE LILI LO AL AY IE OID EEE PATE A Ait AT ONL A SO REE ALM AL A, te lt, a ns emit POO se, eit genoratne tm ee ure pry a: Pree wwe A < veer : , err vv © er wwy rv weve ey Trerwvyy* WOO ew wwe wrerewrry. were vee Tw ferry LAS AAA AD —s ae . ° ver wvwrre , aA Ss - @ rere ee eee “* ywurY ys d ywweer ‘Ye Vssyye : ‘vrwerwew LARA ALRARALORARE EAD! aA ore wry al ‘et Se a ee ahee . ~~ ww Svvee es rewrey raw , ieee rerwen errweyT 3 > Tes ewes + iy eeuewe cea MURS 1) pe mewenw wewletath-atmenem arms : MABEL RA een Doddae Le en SS i. Deen i vee we : - ree’ rT Lan ve yl (Ce te ewe rere veer ‘ewes Ve'wes% vers 2 ore ts ew sree wweewe err i eitidhemmenmetan wine OFS ee en. Tee ewewe «view eve oF EN TY rere ve owe over +e wy veer ver ee eee ttc “ews eakeoe fe expe TVYTt Bs vr wt 6 oe'wr Uy eee x Verve Tres, . ce = wwe we pa ta , Very vrvr ** "¥. = LZ ss on nae Ttesere veerens vv. er ieee een ae ' nr ar ae ory "rr. wer © vr “orw “elev? © we AJ 4 * papadedaie ae *1,.ee eet, = ot 7 ve" ls 9 ae oO POC ee ewe wees ee er Ow ew we eee eee weer et we vee - -« H rt ww wy 7 eee Ky a ug ae | he in Beaks me | in a ah : ~ ~ eRe) dis ch we ) we eh WWW ine Mwy ry oa 1° or haf de oe 4 . : PE lbh Ly ty hee wyv nwa NWO” MAME res / / wy St Ne! JOM il t™ | SIRENS IIA SSAA I ees Mee Vevey, | eee ubeseuugeuvewt™ Mil | THELEN bee Het ads il ww WM wating ncn meer NPs | 4 “4 | A AAS AAA) ty : \ WW ye ‘vy Or ne Ma dpeste| ww j “a Es P ie + \e/ w/ sa | ry ld Pat dee. vv a b het. oe ae a ." , , . “ ae iin es ecw ii phd sg iw’ is ¥ ee felted: cere - 7 ' r . t _ ! na ne e y . : = ; " a as > a re . a - ‘ é # : is o-/ & F : } z . a A +; ie ~~ “ * os _, af oe Me v f - . a. 3 ma a » + P = . - . ~ — | = 5 . . v HE : ‘ i — s 7 - e 1 < a ~~ ~ e ‘ ee = Ma = 4 cs ~ te ‘ - Ns 1 i 2 a ? tate . a - 6 = * ' Pa i bs In j “s = P s . . 4 = a" ; * # < r oo 5 * = = ng * - = 7: i , .- 4 _ . - 7 ~ < \ - ’ = . - . - i 2 s oo on @ 5 -! S 3 ' , a 3 a d ’ J =. 1 ¢ Pn te “ >a" , - > % = cs ~ i+ q é =“ as « Mh \ , = a = s ai % tind i “wii Spa > z : a ss * . Peas # Pou \ = a ¢ : as ¢ sd . ‘ - - LAr ¥ ¥. f- = = his ‘ ; +> 2 rat vin = . a . s ve — 4 1 - ° . x = . oe > . ‘ , r aah. — { a a fi a ‘ - = == - 1 . = - + < s he > 1 z ; le 7 ; x } i , 2 . ' - P * - - = ‘ \ ‘ = 7 ” ~ ¥ ' ~ ' ? “ - i : _— c 7 Ty , ——— aT aes ce | es ne a ee ap Re SES . ee ee eg Se hm ek . — ~~ = > “-— =e : Oe ee a * PzT) shi (340.6 AS ie; a. me ¥. / 0 G2 Lf Lf % 4 Pla U. S. DEPARTMENT OF AGRICULTURE, *® BUREAU OF ENTOMOLOGY—BULLETIN No. 116.~ (14. |4| 2~ L. O. HOWARD, Entomologist and Chief of Bureau. ies * + \ PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. CONTENTS AND INDEX. IssuEp JANUARY 18, 1915. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1915, - "> Ps “ Y ma a ees? Bret ager, ae | a? le : <0 , te Ke ~ U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN No. 116. L. O. HOWARD, Entomolcgist and Chief of Bureau. PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES, I. SPRAYING EXPERIMENTS AGAINST THE GRAPE LEAFHOPPER IN THE LAKE ERIE VALLEY IN 1911. By FRED JOHNSON, Agent and Expert. I]. THE GRAPE-BERRY MOTH. By FRED JOHNSON and A. G. HAMMAR, Entomological Assistants. IIL. THE CHERRY FRUIT SAWELY. By 8S. W. FOSTER, Entomological Assistant. IV. LIME-SULPHUR AS A STOMACH POISON FOR INSECTS. By E. W. SCOTT and E. H. SIEGLER, Entomological Assistants, Deciduous Fruit Insect Investigations, : V. THE FRUIT-TREE LEAF-ROLLER. By JOHN B. GILL, Entomological Assistant. ees wiles ea | ne Ja! ising PaaS I Is ill a: i ‘¢ : © = ; {2 <= <= 1 * a = ‘ r SS \s i i | x In RY tts oe | if WASHINGTON: GOVERNMENT PRINTING OFFIOE, 1945, BUREAU OF ENTOMOLOGY. i] L. O. Howarp, Entomologist and Chief of Bureau. C. L. Maruatr, Entomologist and Acting Chief in Absence of Chief. BR. S. Currron, Chief Clerk and Executive Assistant. F. H. CHItrENDEN, in charge of truck crop and stored product insect investigations. A. D. Hopkins, in charge of forest insect investigations. W. D. Hunter, in charge of southern field crop insect investigations. F. M. WessTER, 17 charge of cereal and forage insect investigations. A. L. QuarnTANce, in charge of deciduous fruit insect investigations. E. F. Pxiurps, in charge of bee culture. . A. F. BurcEss, in charge of gipsy moth and brown-tail moth investigations. - Rotia P. Currig, in charge of editorial work. MABEL Co.LcorD, in charge of library. Decipuous Fruit INSEct INVESTIGATIONS. A. L. QuarntTanceE, In Charge. Frep E. Brooks, JoHn B. GILL, yl, Noucaret, A. C. Baker, R. A. CUSHMAN, J. F. Strauss, W. F. Turner, J. H. Paine, E. H. Srecier, W. B. Woon, F. L. SmantTon, E. B. BLaKesLeEE, H. B. ScamMMELL, entomological assistanis. E. J. Newcomer, W. M. Davipson, A. J. ACkERMAN, R. J. Fiske, Dwicut IsEty, E. W. Geyer, A. I. Fasis, B. R. Leacn, H. G. Increrson, H. K. PLANnk, 8cien- tific assistants. E. W. Scorr, W. 8. Assort, J. E. Duptey, JR. sdehaled in ey of Insecticide Act of 1910. II . es Bete. ~ ‘ CONTENTS. Spraying experiments against the grape leafhopper in the Lake Erie Valley ae gh a ig a Fred Johnson. . Treatment of nymphs of the grape leafhopper with contact sprays......... Field experiments with tobacco extracts............-.....22--0--- ge g rere nreriiments 1 L907 st bc cece eee ote eeor combined contact and poison spray.........-.-2....-seceee-n sees Effect of grape leafhopper control on quality of fruit.............-......--. . TS ire ny cen re as ui soa Nien mtn eit HO ee oe ens be : The grape-berry moth (Polychrosis viteana Clem.), Fred Johnson and A. G. Sa oa, ian c ha! dw amine Dye ARIS wren Dn wine < o Grates Meh Moh Se wc en wc cin las ian dle iL ag + Lug afi ans Ripe Occurrence of the grape-berry moth in destructive numbers.............- ITEC EG OE TINGLE o.oo wi ms fee © waig 2 aya nal mien nee ach mw owen Habits and character of injury of the larva......................------ hye umnrrerer Or tne larva. 2 20... u on ee ow nae ee ale Saved ene Other insects whose injury to grape berries resembles that caused by the unre etaApe-DeIry MOU..----- 2 Ske ee ee eee sane nee ene memeniary etudies in TO00 oe yo ection cen dane Beavers! = RErE TEM AIF Uae ci) > 5 Si a'yyt cy beep wns woe ead Time of emergence of spring brood of moths...............-. Oviposition of spring-emerging moths in confinement.......- Length of life of spring brood of moths. ............-.......- RET HINO No at Sta a iin So rel A 5 nye nna ard PL Incubation period of first-brood eggs....................--- Length of feeding period of first-brood larve........ De ec i Length of pupal stage of first-brood pupze...... fee seat Time of emergence of first-brood moths....................-. Oviposition of first-brood moths... 2.2... 1. ea ew eee ee Hibernation of first-brood pups... . 1.22.2... eens nee nes ts Length of life cycle of first generation......................- MTORR TY os ee eh NO hh A own: Weal ti pamela yh > «aan Incubation period of second-brood eggs...........-.-..-..-- Length of feeding period of second-brood larvee.............. Date second-brood larvee leave fruit.................--...-. Miscellaneous rearing records for the seasons of 1907 and 1908......... Summary of life-history studies of the grape-berry moth. ............ Parasitic enemies. .... Aen pire eR ryt 8 Nan. CN le a ram Degree of vineyard infestation in Erie County, Pa...................... Page, — NoOCWN HE wCowoenwwwwwwwwww w bd bo wD NN D YK Ee - Orr WONN Ne OOO © CO SD Ow nr © on or or 50 Ww ~] www Co Of CO oe wm COC — — 45 + Ne IV DECIDUOUS FRUIT INSECTS AND INSECTICIDES. The grape-berry moth, etc.—Continued. Page. Remedial] measures... 0.0... ee ae ea 50 The-destruction of fallen leaves...) ~ 325. .242 ee 50 Plowing in late fall or-early spring: O22... Sone ee 51 Bagging the clusters. 2: +... 2. So 5 2 Se 52 Hand picking infested berries: <¢ aauasis. 38: 405+ ee eee 52 Removal:of “trimmings”... 2 2225 ee ee Me ne 62 Experiments with poison sprays.ch.: 2.72.0. Soa eee 52 Recommendations for control... .... 1.2) ashe. eo a 62 Gomelustone ss oie od .2 Seis hs Ae oe ee sist ste eae 66 Bibhliography.....0. >... ---.- 552. Sete odes ee 67 The cherry fruit sawfly (Hoplocampa cookei [Clarke])....-..... S. W..Foster.. 2" Ws Introduction... =: Saco. -iesiee 0/4 teeing ee eae eae ee 73 Seasonal history and habits....... a ee SEPA RES Sle per BBs Peeps ee 74 The adult... 0 soss 2 ssa ke et ee bs oo 74 The eect soe). Sees no 2 be oeicinyesey= ener le ec ieleeeaeee oa 76 The larvae. occ 36 se ne ae ec Se ee SO ete 77 Natural enemies: 222.0. fe2Ge 3 2 SS as oo eee ee 78 Expenments an control....2). 52225 6.22 aciae eee ee eee zi eee 79 Lime-sulphur as a stomach poison for insects... W. Scott and BE. H. Siegler. . 81 Introduction... 2.5.2. 2... el ee a 81 Conditions of the experiments... . 25.225 22.3. 22 2 se eee 81 Fuesitlts.. 22220623 of ce ole oe 2b ee ene ak we Se 83 Miscellaneous tests... ........ iene fk a Bee ee ee 89 Conclusions. . .-- 6 oxo) wo ba 6 ye ele oe 8 og es eee 90 The fruit-tree leaf-roller ( Archips hee Walks) see John B, Gill. . 91 Tntroduction,..0 00). es oak Pee ne ee alae =. 91. FVIStORY 0 Pos ae wos EL bk oe es See ae i 92 Dstrub ution «2 oo Sie ee se hes ics ee 93 Food plants. : .. 2:7. .9: ee eee eee ogee 93 Character of injury.......... LE obeid a Ce Said Sk + a UL ee 94 Deseription of staves... 0. 2 2. 2s Sone ee ee ee 96 dase history amd Waite: 0 skate ack ee NE A MATOS ALN on aa 97 Larval stare... tse one) foe eet. Soe aeeeee er ee 97 Pupabstage 0). ooo oe chop oi 94 cess se = Soe es ey sR The. adult and ege stages... . 002.20 5.2 TTee 99 Summary of life history... .0..2. . sia eee ee — 101 Hibernation... 22 2.33.0. 2. 2! TERE ee ee ee ee Watural enemies. so... 2. 26 Pe Se ee 102 Methods of control 200.0. oc) joc 202k ew ee ee 102 Experimental tests for the destruction of the eggs. ......-.-.---.---- 103 Spraying experiments for the destruction of the egg masses........- 37a Spraying experiments against the larve: .........-..----.---s-+-+5 106 Eacht traps... .. 5. Sac. ee ee ee ee Se Ame I. 107 Conclusions.. 2... 22/2 scp gc ce Se ae ge ere ee 108 Recommendations for controls... Vue Se ee ee 109 Puate I. i. Ill. IV. VI. VII. ‘VIII. IX. ILLUSTRATIONS. PLATES. Spraying against the grape leafhopper. Fig. 1—Rod and single cyclone nozzle used to apply spray to underside of grape foliage. Power supplied by tractor sprayer. Vineyard of Mr. H. H. Harper, North East, Pa. Fig. 2.—Rod carrying two cyclone nozzles used to apply spray to underside of grape foliage. Power supplied by compressed air. Vineyard of Mr. A. I. Loop, North East, Pa.... Comparison of sprayed and unsprayed plats. Fig. 1.—Showing con- dition of vine injured by grape leafhopper in unsprayed plat. Note loss of foliage and also berries from clusters. Vineyard of Mr. W. E. Gray, North East, Pa. Fig. 2—Showing condition of vine in plat sprayed with tobacco extract No. 1 against grape leaf- hopper. Note larger size of berries in clusters, heavy foliage, and ' stronger cane growth. Vineyard of Mr. W. E. Gray, North East, Spraying against the grape leafhopper. Fig. 1.—Gasoline engine sprayer supplying power for two “‘trailer” leads of hose in spraying against grape leafhopper. Vineyard of Mr. J. E. Beatty, North East, Pa. Fig. 2.—Gasoline-engine sprayer supplying power for two ‘‘trailer” leads of hose in spraying against grape leafhopper. Vineyard of Peacock-Rood Co., Westfield, N. Y......-.-.------- The grape-berry moth (Polychrosis viteana). Figs. 1, 2—Adult or moth. Fig. 3—Full-grown larve. Fig. 4.—Pupe..........-.--- . Injury to grapes by larve of first brood of the grape-berry moth. Fig. 1.—Showing destruction of portion of grape cluster as a result of boring of larvainto stem. Fig. 2—Showing cracking of infested berries and also the way in which berries first attacked are secured by web to berries which are attacked later in the development of SCE © 2s 3) See owe Gok ee Mh NS eel Injury to grapes by larvee of second brood of the grape-berry moth. Fig. 1.—Showing clusters of Concord grapes from which infested berries have been removed. Fig. 2.—Injury to Ts by larve just previous to harvests Otirarhes 2/5 ko a Be Outdoor rearing shelter and cage used in life-history studies at North East, Pa. Fig. 1.—Portion of outdoor shelter used in the rearing of insects during 1909. Fig. 2.—Cage built over grapevines in which the generations of the grape-berry moth were reared during 1909. . Spraying against the grape-berry moth. Fig. 1.—Showing size of grape berries at second spray application about the time many of the first-brood eggs of the grape-berry moth are deposited on them. Fig. 2.—Trailer method of vineyard spraying in order to apply the spray to the underside of the foliage or to the grape clusters where MIMS tO MIOUIEGS. Poses ee et eal ee. te eed. Fig. 1.—Cherries injured by the cherry fruit sawfly (//oplocampa cookei). Fig. 2.—Entrance and exit holes of the cherry fruit saw- Page, 16 24 32 60 VI DECIDUOUS FRUIT INSECTS AND INSECTICIDES. Pirate X. Fig. 1.—Cherry blossom clusters at stage of development when most gait of the eggs of the cherry fruit sawfly are being deposited. Hie 2.—Larvee and cocoons of the cherry fruit sawfly.....-.-...-...-- 76 XI. Fig. 1.—Sprayed twig of wild cherry showing larve of the fall web- worm (Hyphantria cunea) feeding on leaves; at right, same, covered with paper bag, to prevent escape of larve. Fig. 2.—Unsprayed twig of wild cherry upon which fall webworms have been feeding for some time; for comparison with sprayed twig.............-.- 84 XII. Stages and work of the fruit-tree leaf-roller (Archips argyrospila). - Fig. 1.—Hatched egg masses on apple twigs. Fig. 2.—Full grown larva. Fig. 3.—Pupx. Fig. 4.—Cocoon and pupal case. Fig. 5.—-Young apples injured ‘by larveessJ72 22... 022 0. sce eee ee 94 XIII. Work of the fruit-tree leaf-roller. Fig. 1.—Apple branch, showing webbing and injury to foliage by larve. Fig. 2.—Apples injured by larvae soto. SLSR TS eee see er 94 XIV. Apple orchard at Canon City, Colo., defoliated by the fruit-tree leaf- (0, |) En AM nem MMe Hag IA uke ie We aay ei 3 94 XV. Excessive webbing by larvee of the fruit-tree leaf-roller............ 94 XVI. Stages of the fruit-tree leaf-roller. Fig. 1.—Egg masses on trunk oi apple tree. Fig. 2.—Moth and extruded pupal case. Fig. 3.— Unhatched egg masses on apple twigs........-...--------+--------- 98 TEXT FIGURES. Fie. 1. The grape leafhopper (Typhlocyba comes var. coloradensis): Adult. ....- 1 2. The grape leafhopper: Nymph of the first stage.........--...----..--- 2 3. The grape leafhopper: Fully developed nymph of the fifth stage... -.- 2 4. Map showing distribution of the grape-berry moth (Polychrosis viteana). - 20 5. Injury to grape cluster by larva of grape-berry moth during and just alter the, bloominhe period: 2... \2ckigsjcee ee ae a 24 6. Pupal cases made on grape leaf by full-grown larve of the first brood of the prape berry Mobs ie. . cise p<. yim See eee 24 7. Cluster of Concord grapes on which many second- brood eggs of the grape- berry-moth-are presents sc..¥ oct i. 0 yiede see Bee ete ee ee 25 8. ‘The grape curculio (Craponius inzqualis): Adult, larva, pupa...----- 26 9. Work of the grape curculio in berry of grape.....---.-...------------ 27 10. Diagram showing time of emergence of spring-brood moths of the erape- berry moth in, 1909.4¢ North Masts Pace) ac os ae a ee 30 11. Diagram showing time of emergence of the first-brood moths of the grape- berry moth in 1909 sat NorthyBastpih ashe. vei. s obs ae a i ee 35 12. Diagram showing time of leaving the grape berries by second-brood larvee of the grape-berry moth, from fruit collected in the field, North Bastyr ais OUD ect ah See Ree, Leste chef c nen VEL alee ba - 40 13. Diagram showing time of emergence of the first-brood moths of the grape- berry moth an 1907.08 Notinubast,) Pa seo ide nls son'e deine tee eee eee 42 14, Diagram showing time of emergence of the spring-brood moths of the grape-berry moth in 1908 at North East, Pa.......5.....-.---..--+:- 43 15. Seasonal history of the grape-berry moth as observed in 1909 at North Beth ose nv n jo sANhs cc pienso eo ald ops tetn old aoe otis ee eee ee 45 16. Thymaris slingerlandana, a common parasite of the grape-berry moth. - - 46 17. Vineyard in which poison-spray experiments were conducted against larvee of the grape-berry moth during the seasons of 1907, 1908, and 1909; vineyard of Mr. W. S. Wheeler, North East, Pa...........-.-- 53 ei a a ILLUSTRATIONS, Vil Page Fie..18. Plat arrangement of poison-spraying experiments against the larvee of x the grape-berry moth in the vineyard of Mr. W. S. Wheeler, North EM one Ala i er ae ee kS ecw Se waynes se dees 53 19. Gasoline-engine sprayer outfit used in vineyard experiments against the larvee of the grape-berry moth in vineyard of Mr. W. S. Wheeler, Worth Fast, Pa., 1907, 1908, 1999. ...... SO Ra ea a eae 54 20. Stage of development of grape blossom cluster at which poison-spray application should be made against early hatching larvee of the grape- berry moth which infest the blossom clusters.........----.--.------ 55 21. Plat arrangement of poison-spraying experiments against the grape- 7 berry moth in the vineyard of Mr. W. 8. Wheeler, North East, Pa., SEE So INE GSTs in gee Sal ce Tee nee 57 22. Overwintering cocoons of the grape-berry moth upon leaf on ground, pemeata a badly infested erapevine....-..--.....-.-2....----ene- 66 23. The cherry fruit sawfly (Hoplocampa cooket): Egg, larvee, adult and RE, SFL, AE Sen den ee ER eh co cre oe wk Re Be mee sx Be OG 75 24. Microbracon sp., a hymenopterous parasite of the cherry fruit sawfly. - . 78 i U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN No. 116, Part I. j L. O. HOWARD, Entomologist and Chief of Bureau. PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. SPRAYING EXPERIMENTS AGAINST THE GRAPE LEAFHOPPER IN THE LAKE ERIE VALLEY IN 1911. BY FRED JOHNSON, Agent and Expert. A ee” ge” et oe = " na f ‘4 i IssuED JuLy 15, 1912. . aysonian Inge) 4 Uys JUL 19 1y.? Voss rw : “onal Museu WASHINGTON: GOVERNMENT PRINTING OFFICE, 1912, BUREAU OF ENTOMOLOGY. L. O. Howarp, Entomologist and Chief of Bureau. C. L. Maruattr, Entomologist and Acting Chief in Absence of Chief. R. 8S. Currton, Executive Assistant. W. F. Taster, Chief Clerk. . CHITTENDEN, in charge of truck crop and stored product insect investigations. . Horxins, in charge of forest insect investigations. . HuntTER, in charge of southern field crop insect investigations. . WEBSTER, in charge of cereal and forage insect investigations. . QUAINTANCE, in charge of deciduous fruit insect investigations. . Parties, in charge of bee culture. : D. M. Rogers, in charge of preventing spread of moths, field work. Roa P. Currie, 1 charge of editorial work. MABEL CoLcorD, in charge of library. a> MoE yO Decipuous Fruit INsEct INVESTIGATIONS. A. L. QUAINTANCE, in charge. FRED JOHNSON, S. W. Foster, P. R. Jonss, F. E. Brooxs, A. G. Hammar, E. W. Scort, R.L. Noucaret, R. A. Cusoman, L. L. Scort, J. B. Gitz, A. C. BAKER, W.M. Davipson, E. B. Buaxesitez, W. B. Woop, E. H. Stecier, F. L. Simanton, entomological assistants. J. F. Zimmer, N.S. Assorr, W. H. S11, entomological assistants, employed in enforce- ment of insecticide act, 1910. II bs CONTENTS. aon so ee nin Side de awed ewe eee seca Treatment of nymphs of the grape leafhopper with contact SOAVGs =. ni rises Seeeenerinents with tobacco extracts........'....----------+------------- TTS 1 OS _ Experiment in vineyard of Mr. H. H. Harper, North East, Pa............ Experiment in vineyard of Mr. W. E. Gray, North East, Pa.............. Experiment in vineyard of Mr. J. E. Beatty, North East, Pa............- Experiment in vineyard of Mr. D. C. Bostwick, North East, Pa Use of combined contact and poison spray... Effect of grape leafhopper control on quality ‘of trait. eee ne Reds EF nee ao os nin a apiawales case len cewnesiheunes ILLUSTRATIONS. PLATES. Puate |. Spraying against the grape leafhopper. Fig. 1—Rod and single cyclone nozzle used to apply spray to underside of grape foliage. Power supplied by tractor sprayer. Vineyard of Mr. H. H. Harper, North East, Pa. Fig. 2.—Rod carrying two cyclone nozzles used toapplyspray to underside of grapefoliage. Power supplied by compressed air. Vineyard of Mr. A. I. Loop, North East, Pa. II. Comparison of sprayed and unsprayed plats. Fig. 1.—Showing con- dition of vine injured by grape leafhopper in unsprayed plat. Note loss of foliage and also berries from clusters. Vineyard of Mr. W. E. Gray, North East, Pa. Fig. 2—Showing condition of vine in plat sprayed with tobacco extract No. I against grape leafhopper. Note larger size of berriesin clusters, heavy foliage, and stronger cane growth. Vineyard of Mr. W. E. Gray, North ae el EM GRRE SI ana ares ae cae Sg III. Spraying against the grape leafhopper. Fig. 1.—Gasoline-engine sprayer supplying power for two ‘“‘trailer” leads of hose in spray- ing against grape leafhopper. Vineyard of Mr. J. E. Beatty, North East, Pa. Fig. 2.—Gasoline-engine sprayer supplying power for two “trailer” leads of hose in spraying against grape leafhopper. Vineyard of Peacock-Rood Co., Westfield, N. Y ...............-- TEXT FIGURES. Fic. 1.—The grape leafhopper ( Typhlocyba comes var. coloradensis): Adult. 2.—The grape leafhopper: Nymph of the first stage................--.--.- 3.—The grape leafhopper: Fully developed nymph of the fifth stage. Ill et Page. ~ a » pc, 3 ‘ 7 ? . « ~ i = L - . ‘ “ J 7 J 5 + ry a A . r , j P j = / a a “ ’ é @ “(een ease a AS y Kk oe be ~ Sea ee ra y “ ; j A) < > a { ; : ee ; ais * ft a . i : : oa : < Ss co z ; 4 ’ # d “/ = be 4 jt ~ a al e 2 : ° i > fe = ~ ae } J D - ‘ ; e 4 : - 4 } ‘ ie ‘ — : . i a. ~ “ " ; 7. a y 7 . ‘ é he ‘ ‘ % U.S. D. A., B.E. Bul. 116, Part 1. D. F. I. 1., Issued July 15, 1912. PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. SPRAYING EXPERIMENTS AGAINST THE GRAPE LEAFHOP- PER IN THE LAKE ERIE VALLEY IN 1911. By Frep JoHNson, Agent and Expert. INTRODUCTION. An insect pest of the grapevine which has increased in abundance and destructiveness in the vineyards of the Lake Erie Valley during the past few years is the grape leafhopper, Typhlocyba comes Say (see fig. 1). Pre- liminary spraying experiments were under- taken against this pest at North East, Pa., by the Bureau of Entomology in 1910. Results of the field work undertaken during that season are presented in Bulletin No. 97, Part I, of the Bureau of Entomology, together with a brief consideration of the characteristics, habits, and life history of the insect, and also the character and ex- tent of its injury to the vine. For this reason the subject matter of this paper deals entirely with experiments conducted Serme the season of 1911. Readers un- °3,, 1 Tne grape leafhopper familiar with the habits of this pest should — (Typhiocyba comes var. colo- radensis): Adult. Greatly en- consult the paper referred to above. fot, Obiuic: Walesa TREATMENT OF NYMPHS OF THE GRAPE LEAFHOPPER WITH CONTACT SPRAYS. During the season of 1911 the grape leafhopper was more numerous and destructive to the grapevines in the vineyards of Erie County, Pa., than in 1910. Owing, doubtless, to the higher temperatures prevailing during June and July of this season, the nymphs (see fig. 2) commenced to appear on the leaves at an earlier date, and the develop- ment of the nymphal stages of the insect were more rapid than in 1910. Since it is in this the nymphal period before the insect has developed 1 2 DECIDUOUS FRUIT INSECTS AND INSECTICIDES, wings (figs. 2-3) that it is most readily controlled by a contact spray, it was necessary to make the application several days earlier than in the preceding season. In addition to this, the number of days when the maximum number of nymphs was present upon the vines before the earliest to hatch had developed wings was materially lessened, thus shortening the period during which the greatest efficiency from the spray applications could be se- cured. In 1910 the maximum numbers of nymphs of the first brood were present on the underside of the grape leaves about July 15 and spray applica- tions were commenced at that date and were con- Tra. The prams teat ~— Uued untill duly 20 before many of the nymphs hopper: Nymph of had changed to adults having fully developed wings. Ke ees oe In 1911, however, the maximum numbers of (Author’s illustra- mymphs were present on the leaves by July 5. By oe July 11 fully 15 per cent of the first nymphs to — hatch were changed to the winged form. Thus there was about a week longer time during which the greatest efficiency from the spray application could be secured in the season of 1910 than in 1911. Effective work can be done, however, after many of the nymphs have developed wings, and if the wingless nymphs are still quite numerous upon the leaves the work may be continued with good results. Owing to the more rapid development of the immature stages of the insect in 1911 than in 1910, there was a partial second brood of consid- erable proportions in 1911, which greatly augmented the injury toward the ripening season. Nevertheless, where vines were thoroughly sprayed against the nymphs of the first brood during the first two weeks in July, only slight injury resulted from the later development of nymphs on _ these sprayed vines. FIELD EXPERIMENTS WITH TOBACCO EX- TRACTS, : Fig. 3.—The grape leafhopper: During the summer of 1911 several field —Funy developed nymph of the experiments, in each case covering several f/th stage. Greatly enlarged. - - 5 (Author’s illustration.) acres, were conducted in vineyards in the township of North East, Pa. In all cases the applications were made against the nymphs about the time the maximum number of the first brood was present on the underside of the grape leaves and before many of the oldest nymphs had changed to the winged form. One thorough application at this time proved sufficient to reduce the SPRAYING AGAINST GRAPE LEAFHOPPER. 3 number of the insects so that those remaining did not materially affect the growth of the vine or the proper ripening of the fruit. These experiments were conducted in different parts of the town- ship and several types of sprayers were used in making the applica- tions. In all cases the ‘‘trailer’”’ method was employed; that is, a trailing hose about 20 feet long was connected to the discharge of the spray pump and a short rod, about 24 feet long, carrying a large nozzle of the cyclone type set at right angles to the rod was attached to the free end of this lead of hose. This rod is held by the operator, who thrusts the nozzle among the foliage with rapid movements, directing the nozzle upward, so that the liquid is thrown upon the underside of the leaves. (See Pl. I, fig. 1.) Two forms of commercial tobacco extract were used in these experi- ments: No. I (blackleaf extract) contained 2.70 per cent nicotine; No. II (blackleaf 40) contained 40 per cent nicotine sulphate. In all of the experiments which follow the tobacco extracts are refer- red to by number. Tobacco extract No. I refers to the form con- taining the lower percentage of nicotine, tobacco extract No. II to the form containing the higher percentage of nicotine. At the dilu- tions used no decided advantage was evidenced in favor of either form of tobacco extract. Both of these substances killed the nymphs that were hit by the spray. The tobacco extract No. I at a dilu- tion of 1 part of extract to 150 parts of water killed all nymphs that were made thoroughly wet by the spray, especially the smaller nymphs, between the first and fourth molts. The full-grown nymphs, unless thoroughly soaked by the spray at this dilution, would some- times escape, probably because their longer legs held their bodies some distance from the wet surface of the leaf. The tobacco ex- tract No. II was effective at a dilution of 1 part of extract to 1,500 parts of water. In the use of the tobacco extract No. II— as with the tobacco extract No. I, where a large percentage of the nymphs were in the last stage; that is, just about to develop wings (see fig. 3)—a dilution of 1 to 1,200 or 1,300 may be more effective in killing the nymphs. In the several experiments con- ducted, however, the dilutions varied from 1 to 100 parts of water to 1 to 150 with tobacco extract No. I, and from 1 to 1,000 to 1 to 1,500 with tobacco extract No. II. In all of these variations of dilu- tion apparently equally good results were obtained. VINEYARD EXPERIMENTS IN 1911. EXPERIMENT IN VINEYARD OF MR. H. H. HARPER, NORTH EAST, PA. The east side of the vineyard of Mr. H. H. Harper, North East, Pa., adjoining the highway had been badly infested by the grape leafhopper for several years. Previous to the undertaking of this experiment 4 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. the vines had each season made a weaker growth as a result of injury by this pest, and the yield of fruit also was being greatly reduced. During the season of 1910 several acres on the east side of this vineyard were sprayed with tobacco extract No. I. This treatment resulted in preventing serious injury by the insect. The foliage re- mained green and healthy throughout the season. There was a greatly increased growth of vine and a higher quality of fruit was secured. The greatest apparent benefit in 1910 was in the great increase in growth of vine. During the season of 1911 the entire vineyard of 25 acres was sprayed against this pest, which was present in fully as large num- bers as in 1910. Saas A tractor sprayer was used in making the application. (See Pl. I, fig. 1.) A pressure of 100 to 140 pounds was maintained and about 175 gallons of liquid were applied per acre. The application was made by the owner of the vineyard, Mr. H. H. Harper. The spray was applied by the ‘‘trailer”’ method (see Pl. I, fig. 1), using a single large cyclone nozzle. The work was done very carefully and thor- oughly. Stops were made at each vine. The pressure was main- tained by driving forward the length of the trailer hose. By having a 20-gallon air-chamber on the tractor sprayer a pressure varying from 100 to 140 pounds was secured, rarely dropping below the 100- pound mark. Under favorable working conditions about 3 acres could be covered per day. The tobacco extract No. I was applied at a dilution of 3 quarts to 100 gallons of water. The application was made, on the 3 acres from which our record of yield was secured, on July 6 and 7, when the majority of the nymphs were small but very numerous. The application was very effective, and on account of the thoroughness with which the work was done only a very small percentage of nymphs escaped being killed by the spray. As a result of this treatment the foliage of the vines remained green throughout the entire season, and the vines made a very heavy growth of new canes. The berries and clusters of fruit were large and of good quality. A record has been kept of the yield for the past three years on 3 acres of this vineyard where the injury by this insect was most apparent at the beginning of the experiment. No attempt to control this pest on these vines was made previous to 1910. ND eas nin cle ~ ote pe Yield of‘fruit was 262 8-pound baskets of grapes per acre. MOSS cos oo ha ag Oe ae Yield of fruit was 423 8-pound baskets of grapes per acre. 12h 5 Sages Soma gy ea Ser Yield of fruit was 796 8-pound baskets of grapes per acre. These results show an increase in yield on the first season’s treat- ment of 161 baskets per acre, and for the second season’s treatment an increase of 534 baskets per acre over the yield of 1909. Since the price received per basket of grapes varies each season, it is difficult to compare cash returns one season with another. Prices a Bul. 116, Part I, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE | Fic. 1.—ROD AND SINGLE CYCLONE NozZLeE USER To APPLY SPRAY TO UNDERSIDE OF GRAPE FOLIAGE. POWER SUPPLIED BY TRACTOR SPRAYER. VINEYARD OF MR. H. H. HARPER, NORTH EAST, PA. (ORIGINAL.) FIG. 2.—ROD CARRYING TWO CYCLONE NOZZLES USED TO APPLY SPRAY TO UNDERSIDE OF GRAPE FOLIAGE. POWER SUPPLIED BY COMPRESSED AIR. VINEYARD OF MR. A. |. Loop, NORTH EAST, PA. (ORIGINAL.) SPRAYING AGAINST THE GRAPE LEAFHOPPER. j \ ¥ ay s _ S C LS 2 A a ra - . r 7 ae ne “ i ° = “7 SPRAYING AGAINST GRAPE LEAFHOPPER. 5 for the past 10 years, however, have averaged about 13 cents per basket. On this basis the cash increase on the treatment in 1910 was $20.93 per acre, and on the treatment for the second season of 1911 the increase was $69.42 over that of 1909 before any spray treatment was made against this pest. The actual cash receipts for the three seasons were as follows: ne ee Unsprayed, 11 cents per basket, 262 baskets, $28.82 per acre. ie, be ae Sprayed, 19 cents per basket, 423 baskets, $80.37 per acre. Serer SS Sprayed, 10 cents per basket, 796 baskets, $79.60 per acre. Since the actual prices in 1909 and 1911 are almost uniform, the increase in cash return as a result of increased yield is readily seen. This increased cash return in 1911 was $50.78 per acre. During these three seasons the general treatment for the vineyard has been the same for each season. The soil was cultivated several times and 420 pounds of fertilizer containing 5 per cent nitrogen, 8 per cent phosphoric acid, and 8 per cent potash were applied each season. A Bordeaux and arsenate of lead spray application, consisting of 4 pounds of copper sulphate, 5 pounds lime, and 3 pounds arsenate of lead to 50 gallons of water, was made just after blossoming. A later application of 1 pound of copper sulphate to 100 gallons of water was made for protection against mildew. Thus the general treat- ment of the vineyard was good and conducive to the securing of maximum results. | The additional cost of material and labor involved in making the spray application against the grape leafhopper was as follows: hs No Ra. Se ae win wpb he ciale co 2 ee oe Ose ogee th Poe OO IRs, ee be eet oot cet eas} OA EF a ee ee ee ee 1.00 EE RIAA ot eee ay in ais ale bested hdc Wiles ck bbe Th ose OS cede 1%6 Tobacco extract No. I (strength 3 quarts to 100 gallons of water, applied 175 SIS peg SINR ae ge per gallon... .85 NS SE Teo 2 Pn a 3. 36) Sennen Or apraying 3 acresyper day)... 2... 25 2c. 62 ne ee ewe wc neneeees 8. 36 mera L ACTO! st te ee Sites Dale olan Sattees 2.79 The power was supplied by a tractor sprayer. There is no doubt that this tobacco-extract application during the past two seasons has effectively controlled the grape leafhopper and is largely responsible for the increase in crop yield and for the vig- orous growth of vine in this vineyard. EXPERIMENT IN VINEYARD OF MR. W. E. GRAY, NORTH EAST, PA. The vines in the vineyard of. Mr. W. E. Gray, North East, Pa., were badly infested by grape leafhoppers. They were five years old and were bearing a heavy crop of fruit. No spray treatment was given them except with tobacco extract No. I for this pest. About 40814°—Bull. 116, pt. 1-122 6 DECIDUOUS FRUIT INSECTS AND INSECTICIDES, 6 acres were sprayed with tobacco extract No. I. An acre was left unsprayed in the middle of this block. A gasoline- ere sprayer outfit was used to make the application. The ‘‘trailer’? method of application was employed. About 15 per cent of the nymphs of the first brood had developed wings when this spray application was made, July 11 and 12. Nearly all of the nymphs were about full grown and it was thought desira- ble to use a stronger dilution than in the foregoing experiment. The tobacco extract No. I was used at a dilution of 1 gallon to 100 gallons of water. : “4.27. - ee ae eee ee 7,153 pounds grapes The cash value of the fruit was $25 per ton, or $0.0125 per pound. Cash -value.of yield on lacre east of. check: @22. 5). 2 ieee eae see $105. 77 Cash value;ot yield on, Jacre west: ot check. 22.22... -5- ae see ee eee 104. 09 Cash value of yield on 1 acre unsprayed.........-...-- is. a 89. 41 Increased yield on west plat per acre over check was 1,309 pounds, or....... 16. 36 Increased yield on west plat per acre over check was 1,174 pounds, or.....- 14. 67 Net cash gain on sprayed plats after deducting cost of labor and material: Gross' gain on plat west of check per acre. 226.2222... benee es eel See eee $16. 36 Total ‘cost of labor and material per acre... 2o2222 2 ee eee ee eee 5. 33 Net gain resulting from spraying per acre!:-.0s..6-22- 22 -ee- eee 103 Gross gain on plat east of check per acre..-.-.--..-- he Sas ately ate ote ee ee 14. 67 Total cost.of labor and material per acre. -2.) 5.22) ae ee ee 5. 33 Net cash gain resulting from spraying per acre. ..........-..-:------- 9. 34 In addition to this increase in weight of fruit yield it was observed that the berries of the grapes were much larger and of better color than was the fruit on the unsprayed vines. It was also observed that the fruit from the sprayed vines gave a greater weight per basket. 507 baskets from the west plat averaged 20.7 pounds per basket. 497 baskets from the east plat averaged 20.7 pounds per basket. 478 baskets from the unsprayed plat averaged 19 pounds per basket. Bul. 116, Part |, Bureau of Entomology, U.S. Dept. of Agriculture. PLATE ll. Fic. 1.—SHOWING CONDITION OF VINE INJURED BY THE GRAPE LEAFHOPPER IN THE UNSPRAYED PLAT. NOTE LOSS OF FOLIAGE, AND ALSO THE BERRIES FROM THE CLUS- TERS. VINEYARD OF Mr. W. E. GRAY, NORTH EAST, PA. (ORIGINAL.) FIG. 2.—SHOWING CONDITION OF VINE IN PLAT SPRAYED WITH TOBACCO EXTRACT No. 1, AGAINST THE GRAPE LEAFHOPPER. NOTE THE LARGER SIZE OF THE BERRIES IN THE CLUSTERS, HEAVY FOLIAGE AND STRONGER CANE GROWTH. VINEYARD OF Mr. W. E. GRAY, NORTH EAST, PA. (ORIGINAL.) COMPARISON OF SPRAYED AND UNSPRAYED PLATS. et es eee aes j x e * 1 i ky ray F Z 2 * %, rd: . 22 cao oe eon ee eee et tee eee 22 emer Gharacter of injury of the larva........-.--------.--------------- 23 TSE ea 26 Other insects whose injury to grape berries resembles that caused by the larva CIPTEIINENE TIGI EL oto ee Ps ee A ee ee es 26 I 5c wi hs ee we eee 28 ET es 3s ee BAe et Sa oe nk ee ee wbreies evs 28 I rr e522 50 yh a cise Bn ok oe nistla ook Gan ale = dais See 2 2 28 a new a ee we dab ae eine eee eae eee 29 a ook ie al WS Ee ae Re RPE ashes da ee 29 i an BS SS Se 30 Cnmmrantates aN CQO) S22 255520 .2222.. 5 os fee eed Seed es eee 30 meer NSE eet a cee ee 2st sob et eS 30 Time of emergence of spring brood of moths........-.-..--------- 30 Oviposition of spring-emerging moths in confinement............ 31 Length of life of spring brood ORY Misi elma 20) risc ti eadiece ied 32 IPE in fo adr Ytd oe oss hd eb Wad ees 2 2 oe an faeupation period of first-brood eggs.......-.-.---..------------- 32 Length of feeding period of first-brood res AE Leh Ai ceD ey: 33 Length of pupal stage of first-brood pupe ...-....--...----- St oes 33 Time of emergence of first-brood moths....-.......--------.----- 34 Pmnalison OL first-brocd moths... -.....-....<..-2-+.-2-'-20-2 35 Paperaiatign. of first-brood pupe.......-..-...-22-.--.2-.--2425 36 Penein of life cycle of first generation...............--.-.------- 37 IIRC fi. ce ee eS a Cae CS: SNe ee od 38 Incubation period of second-brood eggs..........-.------------- 38 Length of feeding period of second-brood larve....-..---.------- 38 Date second-brood larve leave fruit...........-..-----.-----.--- 39 Miscellaneous rearing records for the seasons of 1907 and 1908...........- 4] Summary of life-history studies of the grape-berry moth................... 44 I ye ee kd don ede ean wwe ne vens 45 Degree of vineyard infestation in Erie County, Pa.........................-. 49 se eG soe hod a = pia ce ont in wo abe’ a wk 50 Snatimt Or TALCT legves,..........--..----+- 0-2-0 nn nen eec cen 50 SE tees Ill OF CQEly SPYilig......--...-..--.--- 24 ---e-e een ne eeeee 5 RN as NS eA et Le ea nee a 52 Seeetne WitGsted DOITiCs.........-......------- 20 sce ence nw nnnnnnneee 52 NI a a yeh icns Win ck ew wie ne S = 0) 10) = =) B tH perry SE Eee! SEaee oS .B Se 1, CORSE“ ee Rv ABR N? 2B VSESP oe Ue 2 ESS) (88) ~~~ 2a. ~ Ib 19 22 25 28 3i Fig. ene showine time of pene of spring-brood moths of the grape-berry moth in 1909, at North East, Pa. (Original.) winter so as to be subject, as nearly as possible, to natural conditions. On May 17, 1909, 1,000 of these cocoons were separated from this mass of leaves and placed in jars in an outdoor rearing shelter (see Pl. VII, fig. 1) and the following emergence record was secured by a daily examination of the jars and the removal of all moths. SPRING BROOD OF MOTHS. Time of emergence of spring brood of moths.—Table I gives the emer- gence of all the moths from these jars. The total number of moths to emerge was 507. The number of moths that emerged from June 3 to June 14 was 28, or 5.5 per cent; from June 14 to July 14, 455, or 89.8 per cent; from July 14 to August 5, 24, or 4.7 per cent. The maximum emergence occurred June 21. (See fig. 10, showing time of emergence of the spring-brood moths.) THE GRAPE-BERRY MOTH. at TasLe I.—Time of emergence of moths of the grape-berry moth in the spring of 1909 at North East, Pa. Date of | Num- |} Date of | Num- || Date of | Num- |} Date of | Num- |} Date of | Num- emer- ber of emer- ber of emer- ber of emer- ber of emer- ber of gence. |moths.|} gence. |moths.|| gence. |moths.|} gence. |moths.|| gence. | moths. July 30 June 3 1 || June 18 18 || July 1 19 || July 14 3 1 6 2 19 17 2 18 15 2 31 1 (4 3 20 23 3 4 16 6 || Aug. 1 0 8 5 21 32 + 11 17 3 2 0 9 1 22 22 5 9 19 2 3 0 10 2 23 25 6 4 20 1 4 1 11 4 24 21 7 14 22 2 5 0 12 3 25 23 8 3 23 0 13 7 26 24 9 4 24 0 Total .} 507 14 te 27 9 10 11 25 0 15 5 28 23 11 6 26 1 16 14 29 29 12 6 27 1 17 26 30 6 13 12 28 0 Since the blossoming period of the grape in the Lake Erie Valley occurs usually from June 13 to June 20, this emergence record of the spring moths indicates that the maximum emergence takes place during and after the blossoming period. This record also indicates that the small percentage of webs containing larve found in the blossom clusters does not represent the full spring brood from spring- emerging moths, as has been supposed by some investigators, but merely represents the offspring of a very small percentage of the earliest appearing moths. 7 Oviposition of spring-emerging moths in confinement.—The female grape-berry moth does not oviposit readily in confinement, which accounts for the somewhat meager oviposition records obtained. No eggs were observed in our rearing cages until the berries of the grape were formed and those found were always deposited upon the berries. TaBiLe II.—Oviposition of spring moths of the grape-berry moth in stock jars at North, East, Pa., 1909. Date of— Days— No. of | Number From stock jar. |ofmoths.| Emer- First Last Before | of ovi- emer- gence of ovi- ovi- Ovi- osition. | 2ece to moths. | position. | position. | position. | P ‘| last ovi- position ———_] ———_— ———_ - ——— ley ji_— 1 10 | June 17} July 1] July 5 14 5 18 2 30 | June 18 | June 24] July 2 6 9 14 3 15 | June 19 |...do....} June 30 5 7 11 4 20 Are o June 30 |...do. 10 1 10 une 5 46 ane - \Tune 25|July 5 4 il 14 6 12 | June 23 | June 27 | July 7 4 11 14 7 16 | June 24} July 1] July 1 7 1 7 8 20 | June 25 | June 29} July 8 4 10 13 9 23 | June 26 | June 30 |} July 12 4 13 16 10 29 | June 29} July 7/| July 9 8 3 10 a RAIS TOR Sa SERS RG oS SE SENS Rael Re Sa Average...... ec a | POR ae ee 6.6 7.1] 12.7 LU anti 1) eee RR: =e] feo en aes) eS a eg 14 13 | 18 Lice Lor ie 2 ) eS a Fe a ee oe 4 1 ' 7 5 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. Table II gives a record of oviposition by spring-emerging moths secured during the season of 1909. This table gives the number of days between emergence of the moth and the first oviposition and also the number of days between.emergence and the last oviposition. The minimum period before first oviposition was 4 days; the average 6.6 days; the maximum 13 days. The average period between the first and last ovipositions was 7.1 days. The longest period between emergence and the last oviposition was 18 days. Length of life of spring brood of moths.—Records from our rearing cages show that many of the moths wil live in confinement for a number of days, especially when food in the form of honey or sweet- ened water is supplied. Table III gives the length of life of 76 moths, showing that the minimum life period was 4 days, the average 12.9 days, and the maximum 23 days. The average length of life of the moths recorded in this experiment very closely approximates that of the moths recorded in Table II, which was 12.7 days. Taste III.—Length of life of moths of the spring brood of the grape-berry moth in con- finement, with food, at North East, Pa., in 1909. Date— Date— Number of Length Number of Length moths. of life. moths. of life. Emerged.| Dead. Emerged.| Dead. Days Days 1) 2 ot eee eo June 19| July 3 Sees Lee June 23 | July 16 23 ARSE eke ee Pe CO ess auliys: 46 La LO Sete tay ce ne June 24 | July 8 7) Sg oa ge Se Osme altidibllyye 4 7h 1S ii\ el 550 3 eel dow sviily) yg 13 GSAS lie Se Fae SECs aI dials Oa 2 ea ete eee sy N he dos-=s|anihy, 9 15 ie Monee we Stine S PSCC S85 oll delay 8) PAU AI (a) Les aiebetiere eel a's aE GOs= aly Oily, all lf Gree eee | June 20 | June 29 Ohler cho 8s! ae July 4} July 12 8 pa ee See ee J 2dois:~. holy oe TON) Qtr aes. eee ee o...-| July 14 10 Se ee eee Pea COnee | nditaliygeres aS | eee epee 2 ae GOS | Roi lyse il OTe AS OP 5 ae feces dozeee | sulyes 9 WO Oe oe ete eee | eee do....| July 16 12 iT eahe aber ees June23 | July 8 L5H [RB eee Ges July 13} July 17 4 1 Aversa ert yeeeon cy |B do...-| July 10 1 | ee ea eee se cS does ee|) duly, 924. 11 ype shee eee eee OOS. sai) dialhy iy QUID: pak Ses Aaa pee Mee do....| July 26 13 TMotalimimber Ofamoths: 2.22225 sos eee aa Se re Se ee . 76 Length of life: IN VOVA CC eo Sino SSR a wie Sale cpuie retain co ede ae ee Se ET SE oOo ee days.: 12.9 Maximum). ..). 52030525524 koi eeck bee aet tae soe bee eeee 6 tee ee eee eee Co) 23 Mi eee eee eee eee ae ee eee ere alee oo tes econ ete ee a do 4 FIRST GENERATION. Incubation period of first-brood eggs.—Table IV gives a record of the length of the egg stage for 21 eggs of the first brood deposited on grape berries in the field rearing cage. The minimum length of the egg stage for this number of eggs was 4 days, the average 6 days, and the maximum 8 days. * Bul. 116, Part Il, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE VII. Fic. 1.—PORTION OF OUTDOOR SHELTER USED IN THE REARING OF INSECTS DURING 1909. (ORIGINAL.) Fic. 2.—CAGE BUILT OVER GRAPEVINE IN WHICH THE GENERATIONS OF THE GRAPE- BERRY MOTH WERE REARED DuRING 1909. (ORIGINAL.) OUTDOOR REARING SHELTER AND CAGE USED IN LIFE-HISTORY STUDIES AT NORTH EAST, PA. THE GRAPE-BERRY MOTH. 33 TasLe I1V.—Length of incubation of first brood of eggs of the grape-berry moth at North East, Pa., in 1909. Date— D: f Date— D: f No. of obser- nats No. of obser- ae vation. Wainer vation. Hatien Laid. | Hatched. 5 Laid. | Hatched. . 1h See See June 25 | June 29 A UDE we eee nea July 3] July 10 7 ae Sa June 26 | July Dal ligl seen acer neva eee do....| July 11 8 7 Nida eee June 27| July 2 | Sey ee dulys 253|2- dos... 6 CU ae 6 ee June 28] July 4 Gi bie ek ee fee es July 6] July 12 6 OS aA Oe do... -| July 5 Heil Osa oeemere ae duly *7)\5.-do. 5 Ore ee eC June 29 |...do. NET fete Oe So ects July 8] July 13 5 Ceo See pean (ee do. . July 6 TR eee Ree oe July On|eeadoe. 4 Rae Se ede 22 June 30} July 7 OCNWLO es rer ats eons July 10 | July 16 6 NA ae July 1/)] July 8 TE \ 2D NSE te Sep July 12 | July 17 5 HEED Epes get es July 2] July 9 Calliolee-c jaye nse eles = do....| July 18 6 Th 2 Se aaa hee do.. July 10 8 Days of incubation: EASE) EO a5 Gehl a oS Each SAIN oe cr ok SIO ed eee ach ERM ELLA eae Ne 6 UR SURER ERAT ATI ec te Scrap aS cee mee) oR llc veri ee teks rs Ee BUCS ane ES Re GEA arar ert AS 8 UNSTELTESU AIT Tesoro et eS VR eye ae eee a a Ret et hy reps es lS Tene a a es sea OO 4 Length of feeding period of first-brood larve.—The records for the length of the feeding period of the first-brood larve are given in Table XI (p. 37), which shows a range from 19 to 33 days and an average of 23.2 days. The small number of observations made was due to the difficulty of securing the deposition of a larger num- ber of eggs from the moths in captivity. Length of pupal stage of first brood.—Table V gives the time of leav- ing the fruit of 285 first-brood larve and the date of emergence of the moths. The average time for making the cocoon was approximately 2 days. The minimum time covered from leaving of fruit to emer- gence of moths was 10 days, the average 15.2 days, and the maxi- mum 25 days. Therefore, deducting 2 days spent by the larva in making the cocoon the minimum pupal period was 8 days, the average 13.2 days, and the maximum 23 days. 60141°—Bull. 116, pt 2—12—4 34 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. TaBLeE V.—Time of cocooning and the length of the pupal stage of the first brood of the grape-berry moth at North East Pa., in 1909. Days— Days— Number of ae Moths Number of ue Moths ——S larvee. Scaife, emerged. Tce hues larvee. rit. emerged. Tee. eh coon. ‘ coon. 2 SS career July 29 | Aug. 10 12 SOU Moni eee Aug. 6 | Aug. 24 18 54 (Us a eer see PRES do....| Aug. 14 16 WDE Wate enyore se Aug. 7] Aug. 20 13 26 ME Sara aS do....| Aug. 18 15 PAU EI Us sere ee oe so GOs |e ATi 14 14 eee ee do...-.| Aug. 23 25 PA al aero GO Ne =e) PAU 22 15 105 1 as aera ae July 30} Aug. 9 10 MOM |W allece ese eee: -2 00: ... =|) Ate) 23 16 16 PE OEE PR eee do....} Aug. 10 11 DD ARO aye: cters ore ee --d0....| Aug. 24 17 102 1S See Ie do. Aug. 12 13 ies el eee oe 22QOne == |) Auge 27 20 20 Alu tes = ot Magee do. Aug. 13 14 DOV || Mises anaes Aug. 8} Aug. 23 15 15 Qik es do. Aug. 14 15 1a) | eee oe .-do....| Aug. 24 16 96 Nk Lay Pema eee do. Aug. 15 16 SQ ali Soe ea .-do...-| Aug. 25 a7 289 Lae ees ee do....| Aug. 16 17 ZA Diao. crete stay oes =-d0,,-- =| Aug. 26 18 36 Sey rees A July 31] Aug. 14 14 OS al eee eee es EO @aas |) NWS, i 19 19 AOR cree vic en do....| Aug. 15 15 GOs Meee Sook re Aug. 9} Aug. 22 13 13 Pee i alles doze =| Atwe. 16 16 Ge i Deeeeeecres ..do....| Aug. 26 16 80 1 US eee PANT cael Atel 14 196 M25 oe ee a2 CLoz Aug. 26 17 204 (Oe Ee eee BS do...) Augs 46 15 SY}: |i A See oe S65 45 a|) ANOS 27 18 36 See sees Aug. 2 | Aug. 15 13 BO) (NR seo Aug. 10 | Aug. 22 12 12 SE es eae do...-| Aug. 16 14 IUD ee ae eaae .-do....| Aug. 26 16 160 PAs aL eee a Lee dose. a) Aue iy, 15 SO WON eee. <2 SOO. Aug. 27 17 153 1 Lak seore ee Aug. 3] Aug. 13 10 LOM See ese E200" Aug. 28 18 144 Se Psa | aa do....| Aug. 16 13 PAS Y i We eee es Fedoseee|) Aue. 29 19 19 To reese gh eS (aay do....; Aug. 17 14 ESSA Tcl ios se ae Aug. 11 | Aug. 22 ii il ae ees a do....| Aug. 18 15 DG || severe gh 4 2 SAC Op ee i ANI eee 2p 14 14 Sessa eal Cee do....| Aug. 19 16 A Selle Diets ne ee == doe Aug. 26 15 30 Die ee nyse bs Aug. 4] Aug. 17 13 265 || 4se. 2-2 eadior Aug. 27 16 64 Sikes 33 ae ee do....| Aug. 18 14 AO lee aoe =2d oz Aug. 28 17 a; Dee Renee lie. do...-.| Aug. 19 15 SO lel Sareea ee ee ..do...-| Aug. 29 18 18 fe St eh do....| Aug. 20 16 B25 ees Aug. 12 | Aug. 27 15 30 Arigna Aug. 5| Aug. 19 14 510) een gee eee ..do...-/ Aug. 28 16 48 ae Rs a eee do....| Aug. 20 15 | Bee Sees .-do. Aug. 29 17 51 eee EEE do....| Aug. 22 17 illo | ales Seas .-do. Sept. 1 20 20 1 eee Aug. 6] Aug. 19 13 247 1K ee erge a5 55 do...-.| Aug. 20 14 266 || 285 4, 334 2) Fi i ie Be do Aug. 22 16 64 } Days O00) ee ee ee eee i A ee ae ere ea ie Wadena ened icacsobsomoor 15.2 Maxam tm’. oo sche slat whe a ok See ee ae SR oh es ey 25 MAAN. Foie woe edit aye fnicle de moe 2 HS odie aio aioe ew a eo eee gat eee eee 10 Time of emergence of first-brood moths —The material for securing this emergence record of the first-brood moths was taken in part from the large rearing cage in which the eggs had been deposited by earliest emerging moths in the spring. Infested grape berries were removed from the vine in this cage a short time before the larve had reached their full growth. The rest of the material was collected from the open vineyard on August 2, 9, and 10. Since larve were found in webbed clusters in the open vineyard several days before any larvee were found in the rearing cage it is probable that a few of the earliest full-grown larve of the first brood had escaped from the fruit before it was collected to secure this record, thus making the date of the first-emerging moth in this record a few days later than actually occurred under field conditions. Since the date of the last moth of the spring brood to emerge in our rearing jars was August 4, and the date of the first moth to appear from the first-brood rearing material was July 31, there is evidently an overlapping in the emergence of THE GRAPE-BERRY MOTH. 35 moths of the two broods in the field. Table VI contains a record of the emergence of 403 moths, and a glance at the table will show that the maximum number of these first-brood moths emerged from August 14 to August 29. The rate of emergence is graphically shown by the curve in figure 11. Taste VI.—Time of emergence of moths of the first brood (summer nape of the grape- berry moth at North East, Pa., wn 1909. ¢ | Date of | Num- || Date of | Num- || Dateof | Num- |} Date of | Num- emer- ber of emer- ber of emer- ber of emer- ber of gence. | moths. gence. | moths. gence. | moths. gence. | moths. July 31 1 |} Aug. 19 34 || Aug. 30 5 || Sept. 10 1! Aug. 9 1 20 32 31 13 11 0 10 5 21 1 Sept. 1 4 12 i 11 0 22 17 9 13 4° 12 9 23 fi 3 7 14 0 13 7 24 19 4 4 15 0 14 18 25 23 5 0 ||——_—_—_ 15 28 26 27 6 4 Totali. - 403 16 24 20 23 ik 2 aly 18 28 27 8 1 18 10 29 18 9 1 Oviposition of first-brood moths —The oviposition records of only a few moths of the first brood were secured and are not numerous enough to give an adequate idea of the length of this period. The ) On 20 ” <= ° = = O15 S vd oO € = =. “12 Ih Ib 18 20 22 24 2b 28 350 August September Fic. 11.—Diagram showing time of emergence of the first-brood moths of the grape-berry moth in 1909, at North East, Pa. (Original.) same difficulty in getting the moths to oviposit freely in confinement was encountered as with the spring-emerging moths. Table VII gives the oviposition of a few individuals of the first brood. a" 36 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. Taste VII.—Ovposition of first-brood moths of the grape-berry moth in stock jars at North East, Pa., in 1909. Date of— Days— No. of | Number From stock jar.| of moths.| Emer- First Last Before | of ovipo-| _°™e!- gence of | ovipo- Ovipo- ovipo- ees gence to moths. sition. sition. sition. * | last ovi- position. Mee See 10} Aug. 18 | Aug. 27 | Aug. 27 9 1 9 Fe a ed) 21 | Aug. 19 |...do....| Sept. 8 8 13 20 Shree 21) Avie. <20 |-.2d0- 2.4 Aue. 27 7 1 i Al pecans 4! Aug. 27} Sept. 5| Sept. 5 9 1 1 AVCTASC: 2 oases Sch aseee eee Eee 8.2 4 9.2 Mieasxalrnn tyra 23 SaaS ee 9 13: 20 Mian UE 2 = oe = i me eens Sere ae a 1 1 Hibernation of first-brood pupx.—Toward the end of July before the eggs of the second brood had been deposited a large number of infested grape berries were collected in order to determine if all of the first brood completed the cycle and emerged as adults, or if some of them passed the winter as pupe. Tables VIII and LX give the record for 374 larve. Deducting the dead and parasitized individuals from this number, a complete record of 321 specimens was secured. Two hundred and ninety-two adults emerged from July 29 to August 15. After the latter date no adults emerged. Twenty-nine live pupe failed to transform and hibernated. TasLeE VIII.—The relative number of transforming and wintering individuals of the first brood of the grape-berry moth, North East, Pa., 1909. | Number of— Date eae larvee ae tee Moths | hiner. ane, Dead emerged. nating. | sitized. 19 | July 29 13 0 0 6 20 | July 30 20 0 0 0 13 | July 31 12 0 0 1 a i Nag A 21 0 0 0 16 | Aug. 2 14 0 0 2 SFO UN at 30 0 il 1 13 Aug. 4 10 0 2 1 18 | Aug. 5 12 0 2 4 50 | Aug. 6 45 0 1 4 Dan PATER 19 0 1 3. 36 | Aug. 8 30 2 0 4 25 | Aug. 9 20 0 1 4 32 , Aug. 10 24 1 1 6 15), Aue. Ut 10 3 1 1 13 | Aug. 12 11 1 1 0 1 | Aug. 15 | 1 0 0 0 10 | Aug. 26 | 0 9 0 1 7 sept. lan 0 7 0 0 5 | Sept. 13 0 4 0 1 3 | Sept. 12 0 1 0 2 2 | Sept.18 | 0 1 0 1 we ~ THE GRAPE-BERRY MOTH. BT Taste I1X.—Summary of Table VIII showing number and percentage of Jirst-brood larve of the grape-berry moth that transform. Observations on— Number. | Per cent. RITE PIOIETI PEN PO a hoe ea. Sse eee eee ween ee Ps Maha a “ae. SESE Oe ee 374 100. 0 Pn TIPIOMEIRPFINIRUINOIMELPOC 9. 2. 22. << - oe eee sep ee meen ne tebe ee ces eklneey- 292 78.1 RURIIEMIIMEMITIMISUPIUIIES «2 2 ee ee eben te newer teens 29 re 28 aC IOn Aras ZEO IAT VSS <2. oe cine ea ee tla e cle ee bee dew sess nce Yee EO ae eee 11 2.9 PP EIEMMIEMONITIOVICUAIS 2. . 2. 2255 tee see os nel nc bcc cee cecenet aedde sce deans cus 42 152 Length of life cycle of first generation.—The results of the pre- ceding observations on the separate stages of the grape-berry moth have been summarized in Table X, which shows an average period of 44.2 days for the life cycle of the first generation. TasLe X.—Life cycle of the first generation of the grape-berry moth as determined from observations on the separate stages; summaries from the previous tables. Stages of development. Average. | Maximum.} Minimum. Days. Days. Days. 6.0 8 Me ot oh ome bee die anode anita dacden 4 IIE BT en ia oe ee in oie ine nn ee gees 23.0 33 19 IIe ee oo be eee el Ye dee \ 15.2 95 10 SSE GA ee : meraracion Of lifecycle. ......----).--- eee ee ke 44.2 | 66 | 33 TaBLtE XI.—Life cycle of the first generation of the grape-berry moth, as observed by rearing in 1909 at North East, Pa. Dates of— Days duration— Feed | No. = | | erves se Egg Mathie) heavi Emerg- | Incu- ing Life | -_ i - eaving | Pupa- : : mak- | Pupal 2 Sg ing. fruit. tion. nee et Cpe pera ing stage cycle. : | Iarvee, | cocoon. \ fet Li ee ol iwi duly JOi) Aug. 5 | Aug. 9 |..-......- 8 26 a Ne ace rrsee ge | Pye on) ouly 11) July 31 ).......... Aug. 14 8 OM Wki.coh cbr ak meee | 42 3 | July 5 (OX Se eee GOs pers ea Les Aug. 18 6 20) Eo 8 Ves a ee 44 | mee? | July 12 |...do..-.|_........- ug. 16 5 LIK og Pease ft a | et ae 40 a eee Mee eRe Agger Pyle Be 5 25 A eee es ee Peaeiiye & | oily 13 | Aug. 4) Aug. 6.]....-.5... 5 22 ag ae a ae ae Pelee G0... -|...00.. ATES 5 Ht Opa xe | ATIC. 5 23 bos 13 42 8 SRM TOS fo etic clo eiacaccanulens do LS (A a) Rae 26 Je 42 | S| duly 9 |...do.. G0 A al) hl em 4 23 1 al ee tte | Merc et 10 ea OO. AU OMAP Of (oP op) an «os 4 24 Rs West sal eae cee ur Ieee. 5. do... Aug. 15 ; Aug. 17 | Aug. 31 4 33. Bal 14 13 12 | July 10) July 16) Aug. 5] Aug. | Os ied haber 6 20 DAEs oe ae ee J ee PE AA Glos thn wake. «i Ohnetel sty 2 5.4 | 2321 1.9 | 135 | 43.8 | ER Re ae Eee 8 33 3 14 53 | ot oo Ny whan ukipe e 4 “ Fi ee ¥ 1" oe A. GB. ©, Bul. 116, Part IIT. D. F. I. I., Issued January 31, 1913, PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. THE CHERRY FRUIT SAWFLY. (Hoplocampa cookei [Clarke]). By S. W. Foster, Entomological Assistant. INTRODUCTION. The cherry fruit sawfly is an insect comparatively little known to science. It was first described by Prof. W. T. Clarke in the Cana- dian Entomologist, volume 38, No. 11, page 353, under the name Dolerus cookei. In 1910 specimens of this species were brought to the attention of Mr. S. A. Rohwer, of the Bureau of Entomology, who referred it to the genus Hoplocampa. As he was unfamiliar with the type of cookei, he considered that it represented an unde- scribed species, for this latter was destroyed in the insect collections by the San Francisco fire. Mr. Rohwer, however, as a result of the examination of abundant material, has come to the conclusion that his and Clarke’s species are the same insect, which should now be known under the name of Hoplocampa cooker (Clarke). Mr. Rohwer’s description of the species as Hoplocampa californica is given herewith, as taken from Technical Series No. 20, Part IV, of this bureau, page 143: Female.—Length 3.5 mm. Clypeus broadly, shallowly, angulately emarginate, lobes broad, obtusely triangular; supraclypeal area convex, finely granular; antennal furrows wanting, antennal foveze small; middle fovea elongate, shallow, not well defined; ocellar depression small, distinct, not sharply defined; postocellar area well defined on all sides; head and mesoscutum with small, separate, well-defined punc- tures; antennz rather slender, third and fourth joints equal; sheath slightly concave above, slender, convex below from apex; cerci short, stout; stigma broadest near base, strongly tapering to apex; transverse radius strongly oblique, in apical third cell; third cubital cell longer than first and second combined. Black; clypeus, labrum, mandibles (except piceous apices), orbits, occiput (except postocellar), tegule, anterior legs (except coxze), intermediate femora, and part of posterior femora reddish yellow; posterior femora in part, most of four hind tibize, and tarsi black or brownish; wings hyaline, iridescent; venation pale brown, stigma in part pallid. Paratopotypes show that the four hind legs may be mostly black, the posterior orbits pale and the pale spots of the occiput reduced in size. 66713°—13 73 74. DECIDUOUS FRUIT INSECTS AND INSECTICIDES. _Male.—Length 3 mm. Clypeus more obtusely emarginate than in female; third joint shorter than fourth; stigma not strongly tapering; hypopygidium narrowly rounded atapex. Black; antenne, head (except interocellar area), margin of mesoprescutum, lati, pectus, legs, and venter reddish yellow; wings as in female. Type locality.—Suisun, Cal., March 10, 1910 (R. W. Braucher); eight females and one male. Type.—Catalogue No. 13471, U. 8. National Museum. On April 20, 1909, while inspecting the cherry orchard of Mr. — Charles Barnes, Suisun, Cal., for the extent of injury caused by the pear thrips, the writer found several cherries infested with small white hymenopterous larve. The full-grown larve were about five- sixteenths of an inch long and apparently did most of the feeding inside of the kernel, or in the flesh immediately adjoining the kernel. Although the cherry crop was light the injury was quite general, and further search on April 25 showed the little larve in greater or less numbers in most of the cherry orchards of the Suisun Valley. A large series of counts made of the fruit in Mr. Barnes’s orchard showed approximately 80 per cent of the fruit to have been injured by these larvee. At this latter date, April 25, most of the larve were full grown. Some had evidently finished feeding and had left the fruit. How- ever, careful search in the ground under the trees failed to show the presence of any larve or pupe. A large quantity of infested fruit (See Pl. IX, figs. 1, 2) was taken to the laboratory for further study and life-history observations. SEASONAL HISTORY AND HABITS. All of the larvee in the rearing cages had left the fruit and had gone into the soil in the bottom of the cages by May 5, 1909. None of them pupated among the sticks and trash which had been placed in the cages on top of the soil. The cages were sunk in the ground to approach as nearly as possible the normal out-of-doors conditions. Unfortunately all of these larvee were killed by drainage water from a near-by sink seeping into the cage during the absence of the writer. In June, 1912, the writer received from Mr. P. J. O’Gara, Medford, Oreg., a consignment of cherries showing the characteristic injury caused by this species. Mr. O’Gara stated that he had observed the larvee in a few orchards in one locality in Jackson County, Oreg., and that this insect also attacked prunes. So far as the writer has learned this is the only occurrence of the cherry fruit sawfly outside of the State of California. THE ADULT. Close watch was kept in the spring of 1910 for the first appearance of adults in the field. Mr. R. W. Braucher, who was detailed to look after the demonstration spraying for pear thrips in that locality THE CHERRY FRUIT SAWFLY. 15 for the Bureau of Entomology, kept a close watch for the first appear- ance of the adults of this species. On March 10, 1910, he found three female sawflies (see fig. 23, d) in cages nlaxtted under trees in the orchard and used for the emergence records of the pear thrips. Four more adults were caught in the cages on March 12, and two dead ones were found outside of the cages. These had evidently ‘been killed by the spraying for thrips the previous morning. The first males were found March 16 and after this date both sexes were quite numerous for some two weeks or more. The Black Tartarian cherries were just beginning to bloom at this time. The writer spent considerable time in the Suisun section at this period, making a further study of the life history and habits of the Fic. 23.—Stages and work of the cherry fruit sawfly (Hoplocampa cookei): a, Egg; b, position of egg in cherry blossom; c, larva; d, adult sawfly; e, saw of ovipositor; f, serrations on ovipositor; g, sheath of saw; h, head of adult sawfly; i, infested cherries. (Original.) insect. By March 20 adults of both sexes were plentiful, but the females far outnumbered the males. As many as 40 individuals were observed in one tree, two-thirds to three-fourths of which were females. The adults were very sluggish in the early mornings and could be picked up with little or no difficulty. Toward noon, as the atmosphere grew warmer, they became more active, but even then many individuals could be caught in the trees. The adults may be found resting on the leaves, leaf stems, blossoms, both outside and inside, and on the twigs. A few were observed feeding on the nectar of the more advanced flowers. In confinement the adults fed quite freely upon sirup and water. So 76 ~* DECIDUOUS FRUIT INSECTS AND INSECTICIDES. Egg laying had begun only sparingly on March 21, but by the afternoon of March 23 many eggs could be found. A thorough search in three different orchards failed to show any larve. Ovipo- sition was at its height about March 23 to 30, and was practically over by April 5, the adults having mostly disappeared by this time. The females seem to die off in advance of the males, showing about the same comparative difference as was the case at the beginning of the emergence. On April 3 and 4 as high as eight males to one female were noted. On April 6, two orchards were closely examined, and while many males were in evidence not one female could be found. THE EGG. Egg laying began in 1910 about March 16, just as the Black Tartarian cherries were beginning to open first blossoms. The females oviposit quite freely in the orchards, always on blossoms just about ready to spread the petals. (See Pl. X, fig. 1.) The greater number of eggs are deposited in the sepals of the flower, although some are - deposited in the upper portion of the calyx cup, but only in rare cases are any eggs deposited below the middle of the calyx cup. The female inserts her ovipositor in the tissue, usually from the outside, making, for the size of the insect, a rather large, deep incision and placing the egg in the opening just made. The egg is usually placed at such depth that it can be seen from the opposite side of the sepal. The egg (fig. 23, a) is 0.6 mm. long by 0.3 mm. wide, whitish, shghtly shiny, and een kidney-shaped. Incubation.—Of a total of 35 eggs deposited bagten 8 a.m. March 21 and 8 a.m. March 22, 27 had hatched by 8 a. m. March 25, the others hatching during the Po Another batch of four eggs, deposited March 25, hatched March 30. There were three other observations in which the eggs hatched in five days after oviposition. Mr. Braucher reports another instance of eggs that were deposited on March 28 hatching in the afternoon of March 31. Thesummary of these records -together with many field observations shows the length of time re- quired for incubation to vary from three to six days, averaging from four to five days. This time is influenced by temperature conditions, as eggs kept indoors required from 18 to 36 hours longer than eggs kept outside. The time of hatching coincides very closely with the falling of the petals from the blossoms of the variety attacked. Usually the eggs are deposited at or just prior to the opening of the petals and hatch with the falling of the petals. One very mteresting observation was that the adults invariably deposit their eggs at this stage of blossom development regardless of the variety. In one Bul. 116, Part Ill, Bureau of Entomology, U.S. Dept. of Agriculture. . Brae FiG. 1.—CHERRIES INJURED BY THE CHERRY FRUIT SAWFLY (HOPLOCAMPA COOKE)I). TWICE NATURAL SIZE. (ORIGINAL.) Fia. 2.—ENTRANCE AND EXIT HOLES OF THE CHERRY FRUIT SAWFLY. NATURAL SIZE OR TWICE NATURAL SIZE. (ORIGINAL.) WORK OF CHERRY FRUIT SAWFLY LARVA IN IMMATURE CHERRIES. Bul.116, Part III, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE X. FiG. 1.—CHERRY BLOSSOM CLUSTERS AT STAGE OF DEVELOPMENT WHEN MostT OF THE EGGS OF THE CHERRY FRUIT SAWFLY ARE BEING DEPOSITED. ABOUT TWICE NATURAL SIZE. (ORIGINAL.) Fic. 2.—LARVA AND COCOONS OF THE CHERRY FRUIT SAWFLY. ABOUT FOUR TIMES NATURAL SIZE. (ORIGINAL.) THE CHERRY FRUIT SAWFLY. 77 orchard under observation there were early and late blooming cherries in alternating rows. Eggs of this insect were numerous and. a few _ larve present before the adults apparently noticed the later-blooming varieties. Afterwards, when the petals of the Royal Anne cherry were beginning to open, eggs were just being deposited in numbers in this variety while the Black Tartarians immediately adjoming these trees had shed the petals and the larve had mostly hatched and only very rarely could an egg be found. The time required for incubation of the egg is practically the same in all varieties of fruits. Ordinarily only one egg is deposited in a single flower. ‘Occasionally, however, two and very rarely three eggs were found in the sepals and calyx of one flower. THE LARVA. Upon hatching the young larva may feed for a short time in the tissue immediately surrounding the egg cavity, or on the inner sur- face of the calyx cup, but it soon finds its way to the bottom of the | calyx cup and eats directly into the newly formed cherry. The larva at this time almost always enters the fruit through the base imme- diately adjoining or very near the stem. Going directly to the center of the cherry, the larva eats away the small kernel. The cherry thus injured soon withers. In two to four days after entrance the larva makes its first molt and leaves this cherry in search of other and fresh food. When attacking the second cherry the larva may enter the fruit through almost any place on the surface but invariably goes directly to the seed, and if this has not hardened eats out the kernel, as was done with the first fruit, seeming to prefer this to the meat of the cherry. The second cherry, being larger when attacked, usually withstands the effects of feeding longer and the larva may remain inside for some six to ten days or even longer. The growth of the cherry is checked and it frequently hangs on the tree retaming a rather pale green color for some days after growth ceases and the fruit has shriveled. When the kernel in this second cherry has been destroyed the larva usually goes to a third cherry and if the pit has not hardened eats it out as before. However, when the pits become too hard the larva feeds on the meat of the cherry near the pit until it attains full growth in much the same manner as does the plum curculio in peaches. In Plate IX are shown photographs of the injured fruit and the entrance and exit holes of the larve. Each larva usually destroys three cherries, although some go to the fourth, while a very few complete their growth in the second cherry. The time required for the larve to attain their full growth averages from 22 to 26 days. In Table I the record is given for 34 individuals. 78 DECIDUOUS, FRUIT INSECTS AND INSECTICIDES. TaBLE I.—Length of larval stage of the cherry fruit sawfly, Suisun, Cal., 1910. Date. Observation. Mar. 25..| 34 larvee hatched in cherry blossoms in cage. Mar. 27..| Supply of fresh food given (branches of young fruit from cherry tree). Mar. 30..| 24 larvee had entered second cherry. Apr.1...| 6 more larve had entered second cherry. Apr. 6...| Fresh food put into cage. Apr. 8...| 16 larvee found in third cherry; 6 larvee still in second cherry. Apr.12..| Fresh food put into cage. Apr. 16..| 3 full-grown larvee left fruit. Apr.17..} 2 full-grown larve left fruit. Apr.18..| 5 full-grown larvee left fruit. Apr.19.. Do. Apr. 20..| 3 full-grown larvee left fruit and 5 full-grown larve found in trash at bottom of cage. All the larvee had left fruit at this date. When full grown (see fig. 23, c) the larva leaves the fruit and works its way into the ground, where it constructs a small parchment- like cocoon. The cocoon will be found from 3 to 7 inches below the surface, the depth varying some- what with the texture of the soil. It is elliptical or oval in shape and from one-fourth to three-eighths of an inch long. Inside the cocoon is smooth, dark a papery texture; and somewhat brittle, especially in dry soil, so that it is easily broken. The outer surface of the cocoon is covered with fine particles of soil, giving it the appearance of a small clod of dirt. In Plate X, figure 2, are shown full-grown larvee and cocoons, some of the latter being torn partly open. 7 The larva remains as such in the cocoon until the following winter. Some time after the winter rains begin it transforms to pupa and emerges the following March as adult. The pupa has not been observed. There is only one brood each year. Fig. 24.— Microbracon sp., a hymenopterous parasite of the cherry fruit saw- fly (Hoplocampa cookei). (Original.) NATURAL ENEMIES. Two parasites, an ichneumon and a raicrobracon (see fig. 24), were obtained from the material collected by Mr. Braucher. Several large collections of infested fruit were brought to the laboratory for possible parasites, but none was obtained from this brown in color, of THE CHERRY FRUIT SAWFLY. 79 material. It is possible that this species is rather heavily para- sitized at times. The insect has been known in the Suisun Valley since 1905, but caused comparatively little injury from that time until the serious outbreak of 1909. As no spraying had been done in the infested orchards that would be of any value as a control to ‘this particular species it would seem that the parasites, together with more thorough cultivation, have served to keep it fairly well in check. The insect was less numerous in 1910 than in 1909 and the same was true of the years 1911 and 1912. EXPERIMENTS IN CONTROL. Experiments in spraying with arsenate of lead were made in 1910, but in this instance the poison did not prove to be altogether effec- tive. Some larve were killed, but not enough to warrant the recom- mendation of this as a satisfactory treatment in case of a serious out- break of the insect. Further work along this line is desirable. Mr. _ O’Gara, in a letter, reports satisfactory results from the use of arse- nate of lead in the Rogue River Valley of Oregon. Many adults were killed in the early mornings while spraying with 3 per cent distillate-oil emulsion to which sulphate of nicotine had been added at the-rate of 1 part to 2,000 parts of water. This method would most likely be a very effective means of control if all the spraying could be done in the early morning. At this time the adults are very sluggish and can be easily wet with the spray. Perhaps a more likely means of holding this sawfly in check is by careful cultivation. The most serious hindrance to this plan of treatment in cherry orchards is that the roots of the cherry tree close to the trunk are near the surface, and some larve go below the top of these roots. However, it is highly advisable to cultivate the land thoroughly two or three times just prior to the first picking of the Black Tartarian cherries, as most of the larve are leaving the trees at this time and numbers of them would probably be killed. DDITIONAL COPIES of this publication may be procured from the SUPERINTEND- ENT OF DOCUMENTS, Government Printing Office, Washington, D. C., at 5 cents per copy. see aad : ae a s we (stf eon teh? i, te ha * +e ah eS rat H - * jgaee . yes bi Pui lal P . Pig, ‘ re : - 7 ial he swe 4 ere eer * : ; (IN Pu BRR Fit gov Be Pee 2p soshyuo f tes a a Opp aR ef fe Llosa bli : . eee: a a a 28 Sa rieeeves Less 4 Psy 4 (1938. Lior ra 29199 : : : t H | F - y q 4 5 . VA P"Cectep cpt tk | i? iD baa -& { t ' j - 5; to 2° : iz if ; te : ; AS iy seez , ‘ yr fg r P F ‘ * " YP ; 4 bit £)h469 aa ae cist — - : MN - é ie ~ : - + Wry » i * . ‘eae A 4) ae ey 4 ou { by ; 7 - eS ‘ 2 vy ‘ ” y » N f L - en 7 ei ’ * t , Mie bin x Bt ° h sgh Pai, é 1s WO ie oe ie og” \e ' : r By, t % - FOF ey ; ny Ee ’ a > De ER rey PM # ve » ay 4 pit ° : i Bee iF i } iv aoe ? i ’ ‘z z F Bo Check Lime- 14-50, (un- sulphur, and (un- sulphur, and sprayed).| 14-50. arsenate sprayed).| 13-50. | arsenate oflead, of lead | 2-50. 9-50 ae Wek. ..... | 2) FAS RRRE BM AF MICAE Bo iM | PU AYCR Ses lat dae See LAE ee NE NE ee MI eres SRE eee Fee Te aera ease ce Tier Ley Ad i: i MB Litt] SEER. ak “SHIGE Se ee oe: 7 STE RES eG ee eres Een . ae Ogee | ee 4 10 BASU RGAae SHEL ST OR Cee eee ne a epee SS awe ES Cee 3 2 RS SS aS a a eee, ees. ...... | oe Bot. Ba ci. A een er AAAS, | ee Si Say ee res = AS ee ee er 2k fe weal seee Ses oe pt eee see Pi 0 Pn eS) ES Se OS ea 6 Eee Ale oh St ee SR a ee - ee lashes dan. ee es MEE Adds 2. >» Js es ae a Total number a |. auaies 26. Dr hn. viet dead....... 4 20 20 ee Ab i Fe ee eae Number of days re- BR SN ones Te Re SR Seniae aneee Te |: a 13 7 Main dima are a ACESS SEE es: Aer || Square inches of Diweerwver.s ee ee eee | oliage consumed.| 243. 20 0. 73 0.12 84 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. EXPERIMENT II. In order to obtain further data on the killing effect of lime-sulphur another experiment was started July 30, using different strengths of lime-sulphur as given in Table IT. TaBLeE II.—Tests of the killing effect of lime-sulphur on the fall webworm. {Experiment started July 30, 1912, Benton Harbor, Mich.; 20 larvee in each lot.] Larve dying in each lot. Larvee dying in each lot. etn Lot | Lot | Lot | Lot | Yt ante Lot | Lot | Lot | Lot | Hot Becta (ni 1— — | 3— | 4— Sits I~ | 2— } 3— — a examination. —|Check| Lime-|Lime-|Lime- Btsps examination. —|Check|Lime-|Lime-/Lime- an (un- | sul- | sul- | sul- (un- | sul- | sul- | sul- spray-|phur,|phur,|phur, oa spray-|phur,|/phur,|phur, He ed). |13-50. | 38-50. | 6-50. 9-50, ed). |14-50. | 3-50. | 6-50. 9-50, MeN OPS EL a enemas a oA P| eA Aug. - Pea a nate ella ees 2 ee oe Pee Sete PITS ogra td eee B00 oe ee ASS aes a le 1 ESE oe y) ees ee eee eee ee eal omoa\|.. >> 5 Ane Se ee eee 2 1 1 5 6 QO ew cw le wiceie | Sea eo ae tee ol eee | See ee | [ate ee, IIIS |e eee cs oll aie ae Ses Siler am PR Bias Se i 1 1 9 eal ea Total num- . Re Serer ce Eee 3 4 1 14 ber dead. . 1 20 20 20 20 Qe ee ane ee 2 ANG Re SER ie te Number days re- OB eases ells Sei Peto cl seniors see sat quired to kill....|...... 15 12 9 9 MRS ete see ee 4 Seer ee Square inches foli- 1 Ee eee eee | os Dil pam Pesos ya age consumed ...|40.00 | 1.21 | 0.65 | 0.34] 0.83 LB Maes Ee fa ee 7 ee eal hie See eb Se 1 Arsenate of lead was used in lot 5 for comparison with the lime-sulphur solution. In this experiment 15 days were required by lime-sulphur, 14-50, to kill the 20 larve, as against 9 days required by arsenate of lead, 2-50. Twelve days were required by lime-sulphur, 3-50, while lime- sulphur, 6-50, killed the 20 larvee in the same length of time required by arsenate of lead, 2-50. The check lot was discontinued at the end of 30 days, when 1 larva was recorded dead and 40 square inches of foliage consumed. It was found in this test that the number of square inches of foliage consumed decreased about one-half as the strength of the lime-sulphur was doubled, the largest amount being 1.21 square inches. The amount consumed on the arsenate-of-lead lot was 0.83 of a square inch. EXPERIMENT III. In Table III are shown the comparative results of a dosage test consisting of seven different strengths of lime-sulphur varying from 4-50 to 6-50, and four different strengths of arsenate of lead varying from 4-50 to 5-50. PLATE XI. Bul. 116, Part IV, Bureau of Entomology, U. S. Dept. of Agriculture. “AYOMEAM T1VS AHL LSNIVDVY NOSIOd HOWNOLS V SV YNHdINS-AWIT ONILSSL 3O GOHLIW CTIVNISIYO) “SIM_L GSAVYdS HLIM NOSIYVd -WOD HO4 ‘SWI AWOS HOS DNIGAS4 Naag (IWNIDINO) “S/AUV7] JO AdVOSQ LNSASYd OL SVG Y3dv¥d HLIM SAVH SWYHOMESM WWV4 HOIHM NOdf G3Y3SA0D ‘AWVS ‘LHOIY LV ‘S3AV37] NO DNIGSS4 (VANNO VINLNVHdAH) WHOMSSMA AYYSHO AIIM 4O DIML GSAVYEdSNN—'S ‘DI Tiv4 SHL SO HAYV] ONIMOHS ‘AYYSHO AIM JO DIML GSAVHdS ‘1437 Ly—'| “DI Eat ac) t® . , id i ora ins P oon Pe ed c ; > a ; 5 7 > i 5 b \ ‘ 5 1 ae é ' a ~o ad a a. * RS ‘, Tr x = Si = , f = € : a ae 7 =| ba? al + see ee 7 : LIME-SULPHUR A STOMACH POISON FOR INSECTS. 85 Tasie III.—Tests of the killing effect on thefall webworm of lime-sulphur in comparison unrth arsenate of lead. [Experiment started August 8, 1912, Benton Harbor, Mich., 20 larve in each lot.] Larvee dying in each lot. Lot | Lot | Lot | Lot Lot | Lot Lot Lot | Lot | Lot Lot et haga. ava Lot 1— 11— } 12— Date of examination. — | 3— | 4 5— | 6— | 7— | 8 ay Lime-|Lime-[Lime-|Lime-|Lime-|Lime-|Lime-| A'S*| Arse-Arse- | Arse- a l- | sul- | sul--} sul- | sul- | sul- | sul- nate | nate | nate | nate spray- |S" of of of ed). phur,| phur, phur, phur,| phur,}| phur, phur, lead, | lead, | lead, | lead, 4-50. | 1-50. |14-50. | 2-50. | 3-50. | 5-50. | 6-50. | 4°50’ | 1-507 | 2-507 | 5-50. A ee eee en eee! eerie erm 2 ele 2 8 ee nents tees ee afew can lence-nloncakalecsese 1 leet 4 11 15 i Ree Be 3 1 4 5 2 3 6 11 1 10 1 1 oo. Ste ee a o 8 13 6 6 6 4 11 71s ise el NE eee 0 ee 2 8 2 Bah dd Zalact 3 9 Nae ele str no a ee Shileewec on ae pter Fe Se [OMe ae Povareretste Pe ee || ee a Re of. a eae Os Ra aera Sole aoe. | keaae Senne eee te py rae vt | 2a a a eee ee LE ESS eee ES 5 Me Oe Meer se PRE eo Moree SO NS te BPR Bch ee si ace an Rel eee eae ed ee oe 5 ee Rb Sas Bratt Seka wie [lS cca | «cee eee (dis Le MN eines, ec ell Sorc) ee EMa a oe iors a, 3 oil eee call Bee = otc cial Seal | Total number dead. 7 20 20 20 20 20 20 20 20 20 20 20 Number days required to LL sae Sede eee 14 10 10 12 10 10 8 14 10 6 6 Square inches of foliage BOMISMICG. 2-555. 26s. 5. 119.00 | 3.92 | 0.36 OP LOL Oe Sia O73: 110,26: | 2-380 loka Osi 0.10 It will be noted that lime-sulphur, 4-50, killed the 20 larve in 14 days, the same length of time required by arsenate of lead, 4-50. Also lime-sulphur, 1-50, killed the larve in the same length of time as arsenate of lead 1-50, the time required being 10 days. However, in both instances the arsenate of lead killed more rapidly in the beginning than the lime-sulphur. Eight days were required by lime-sulphur, 6-50, to kill the 20 larvee as against 6 days required by arsenate of lead, 5-50. The amount of feeding varied somewhat in this experiment, the largest amount on the sprayed lots being 3.92 square inches where lime-sulphur, }-50 was used, and the smallest amount being 0.10 of a square inch in lot 12 which was sprayed with arsenate of lead, 5-50. EXPERIMENT I[V.. The object of experiment [V was to obtain data on the relation of the killing effect of arsenate of lead alone and combined with lime- sulphur, and to obtain, if possible, data on the effect the addition of one to the other has upon the rapidity of killing. Lime-suiphur alone was used at four different strengths, and also was combined at the same rates with arsenate of lead, 2-50. The lime-sulphur strengths employed were }—50, ?-50, 14-50, and 3-50. Arsenate of lead, alone, was tried out at strengths of 4-50, 1-50, 2-50, 3-50, and 5-50, and also at the same strengths was combined with lime-sulphur, 14-50. The results are given in Table IV. 86 DECIDUOUS FRUIT: INSECTS AND INSECTICIDES. TasLe 1V.—Tests of the killing effect on the fall webworm of lime-sulphur and arsenate of lead, alone and combined. [Experiment started Aug. 19, 1912, Benton Harbor, Mich., 20 larve in each lot.] Larve dying in each lot. | Date of examina- | 7 9¢ y_ | Lot 2—| Lot 3— Lot 4—| Lot 5—} Lot 6—| Lot 7—| Lot 8—| Lot 9—|Lot 10— tion. Gheek Lime- | Lime- | Lime- | Lime-| Arse-| Arse- | Arse- | Arse- | Arse- (un- sul- sul- sul- sul- | nate of | nate of} nate of| nate of! nate of sprayed) phur, | phur, { phur, | phur, | lead, | lead, | lead, | lead, | lead, Prayed)| “2-50. | 2-50. | 14-50. | 3-50... |* 4-50. | 1-50, | 2°50, | 3-50. |) 5-50; Peder 55 ake gee Use Lage eames lel Vegi Mle a Ras, ste 3 SccuEeee 3 4 5 12 WB enka we Detyss alban she 1 2 2 2 2 10 2 13 8 DS oes Soeur tee olny 2 1 8 9 8 7, 14 Dis ee es 217 sen MO See ER Sav a er 8 7 10 6 f [2.2 hs lel See eee en 4 ee DORE 3 Les oly Gale Rae cee 8 fC ees oer eae at Bi ES ese eee i eel STL ee a eee 0 Lie 1 Deal Caeg: 3 a 4 low beeeesleobosee dfaen den isle oes See nae eee 2 S155) ag hae eee ape Oy bio et AM oy Be Pe ce ar | owbewese|eu cece na [al St hep ees 2 a rr Aes ook Oe, Tape ease in eS Re pe Ree ie eet Ae es hit al eS Ay mine Go aoncd Se Geos ce Pee red aaa kann oa ard ie tage eens Reem Menon owe Sic EES eee Sak cai. oF Sot Ne ee ae ere | a eg Peewcavelb ae. Sle lots atte Cate ee WQs co shee sie cen Wares see eee aes Seilnd Hae ee Ne oe ele See ee a orale Sos cee a eee a | 15% 2 Wee ee Rese B |e wensvec|eses cecafecees ree ty fe eset ocean Cols tis aaeacenn Gas Bo pede ee braless holes leases cp ceeetlbseiele sie ee ee Total num- ber dead. - . 8 20 20 20 20 20 20 20 20 20 Number days re- quiredstiomalls= soa 52352-- 12 12 8 8 10 6 6 6 4 Square inches of oliage consumed.| 72.00 Sao 2. 87 0. 17 0. 49 2. 44 0. 36 0. 57 0. 24 0. 02 Larvee dying in each lot. tat 11— | Lot 12— Lot 13— bee 14— yet 15— | Lot 16— fat 17— er 18— pan i ime- Lime- ime- ime- rsenate | Arsenate | Arsenate | Arsenate Date of examination. | s)phur, | sulphur, | sulphur, | sulphur, | oflead, | oflead, | of lead, oflead, 14-50; 1-50; 13-50; 14-56; 2-50; 2-50; 2-50; 2-50; arsenate | arsenate | arsenate | arsenate |-_lime- lime- lime- lime- oflead, | oflead, | oflead, | oflead, | sulphur, | sulphur, | sulphur, | sulphur, +50. 1-50. 2-50. 5-50. 4-50. 3-50 13-50. 3-50. FAGI ER Qe. eesee acta Mane ee ele eee eae 3 10 9 5 1 6 Dae eT RyT ETE ie 2 14 9 10 9 11 6 9 Drei tn ae ce 8 4 Vleet. Beh 2 4 118} i DEE ETE ING 6 2 A jeseee ee -Soleks es eae Bleek oa seal pees ne ee A sa er Py pons A root conloouck eed Peep oaths alee gael eee eee |e ee | Sys 58 AE ha DENS Se7 A SRI ae oS de ee a Ie a, 9 ee Septe 7 Ze. ssc ne sls ees See Meelis Se oh eee ee Ee sya Rs oe |S oe eel | re oe |e Bien Fee Leh Se 2 ef SSM SS. ee SIRE CEL BR ee ee ren ae a ee ee ee | Geo itech eee ees. EE ee Sc oe Pe ek 2 ee ee Bee sad Se Sate low eee ae eevee alia ee Sem ere ee ca, Te a cee ae | Le ie ic tre scutac eee Sec Be Ng I i Pe | eh a | | aR NE jee ene ties ervey EE eo tail ieee, 2 (ESOS Be oe (on apew eb|aece bolts e eee Cie nah: 5 Seamaemee se Oe locas acces space Soke SL Le re) eh et Oe a SO Total number | déades2 [Fh 20 20 20 20 20 20 20 20 Number days re- quired to kill....... 10 8 8 4 6 6 6 6 Square inches of foli- age consumed...... 0. 52 0. 02 0. 28 0. 07 0. 30 0. 19 0. 06 0. 22 None of the larvee strength. on the unsprayed lot died until September 15, 27 days after the experiment was started. On October 3 the records of this lot showed 8 dead, 6 pupated, and 6 missing. Lime-sulphur alone, 1-50, and likewise 3-50, killed all the larvee in 12 days, while the time required by strengths of 14-50 and 3-50 was 8 days in each case, the rapidity of killing being somewhat greater with the latter Arsenate of lead alone, 4-50, killed the 20 larve in 10 days, or 2 days more than was required by lime-sulphur, 13-50. Arsenate i se LIME-SULPHUR A STOMACH POISON FOR INSECTS. 87 of lead, 1-50, 2-50, and 3-50, each killed the larvee 2 days sooner than that required by lime-sulphur, 14-50. Lime-sulphur, 13-50, when added to the various strengths of arsenate of lead did not appreciably affect the rate of killing of the arsenate of lead. The amount of feed- ing was reduced in all cases, excepting that of the strongest solution, lot 14, by the addition of lime-sulphur. On the lots sprayed with lime-sulphur, }-50, ?-50, 14-50, and 3-50, combined with arsenate of lead, 2-50, there was no difference in the length of time required to kill the larve, 6 days being required in all cases. The same number of days was required by arsenate of lead alone, 2-50, but the rapidity of killing was somewhat increased by the addition of lime-sulphur. EXPERIMENT V. In an experiment to obtain data on the sticking qualities of various sprays, three lots of the regular orchard demonstration strength of lime-sulphur, 14-50, were used. The three lots were thoroughly sprayed and allowed to dry. One lot was then washed for 15 minutes under a shower bath, by placing the twig just above the floor in an inclined position, allowing the water to fall upon it. Another lot was washed 30 minutes in the same manner, while the third lot remained unwashed. The same procedure was carried out on three lots of arsenate of lead, 2-50. After the twigs were again thoroughly dry 20 larve were placed on each. The results of this experiment are to be found in Table V. TaBLe V.—Tests of the killing effect of lime-sulphur in comparison with arsenate of lead after washing of each. {Experiment started August 4, 1912, Benton Harbor, Mich., 20 larve in each lot.] Larve dying in each lot. Lot 2— | Lot 3— | Lot4— | Lot 5— | Lot 6— | Lot 7— Date of examination. Lot 1— Lime- Lime- Lime- | Arsenate} Arsenate | Arsenate Check | sulphur, | sulphur,}sulphur,| oflead, | oflead, | of lead, 4 14-50; 14-50; 2-50; 2-50; 2-50; sprayed).| not /washed 15)washed 30) not washed 15|washed 30 washed. | minutes. | minutes. | washed. | minutes. | minutes. EE Eee eee eee ce eee ee CeCe ee he ee Oe See ne Pee, tee Fe els oe ee ow db oak eae eden celw ret luadeeruaans 7 ma eee S22, SO EE ee sg 1 12 Ree ee ee eg te cin ow |noe manu «oe 2 2 AS? SF Seve ee 5 1 a ee) 12 9 i ee 9 2 as 1 4 7 AD oa seh ch dete | Sta alte sdf 7 = CS Se ee ee eee || ae ube ees fos Seo ets one 4 EE ee ere te te cee «a cate a Sates m ose |oars ue dw wpb blacw pe chelence coe coe 4 a eRe Se od bt | ee Cee Dee ee ee Mee ee ee (Rees ee 8 See bel Se Pe Si pate be ah = NOL lad inn ebbao tee ok « wr hbase ddd ce heel tk. .. o 4 eS a ee ys ike palettes ky tel te o Sah. <' eabte ARSE Oe & SKA Able Soaks das 13.cb w Eiken. Total number of dead.... 7 20 20 20 20 20 118 Number of days required to kill.|.......... 13 15 13 7 ll 17 Square inches of foliage con- sumed be tied ohvccnssdune bbde at 111.00 0, 82 1, 56 0. 84 0, 38 1.79 5. 00 1 2 escaped. 88 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. The washing made practically no difference in the killing effect of the lime-sulphur spray, the time of killing varying from 13 to 15 days, and the amount of foliage consumed varying from 0.82 to 1.56 square inches. In the case of arsenate of lead, however, the killing effect was considerably retarded. The length of time required to kill all the larvee when the foliage was unwashed was 7 days; when washed 15 minutes, 11 days; when washed 30 minutes, 17 days. The amount of feeding was 0.38, 1.79, and 5 square inches, respectively. EXPERIMENT VI. To compare the killing effect of commercial lime-sulphur and home- boiled lime-sulphur, an experiment was conducted in which two lots of each kind were used at the strength of 14-50. The commercial products tested 33° Baumé and the home-boiled 30° Baumé. The results are shown in Table VI. TaBLE VI.— Tests of the killing effect on the fall webworm of lime-sulphur, commercial and home-boiled. [Experiment started Aug. 27, 1912, Benton Harbor, Mich., 20 larvee in each lot.] Larve dying in each lot. Ce is Lot 2 Lot 3 Lot 4 Lot 5 © Date of examination. (20 Pt ye (20 larvee)— | (20 larvee)— | (20 larvee)— | (20 larvee)— Ghee (un- Commercial | Commercial | Home-boiled | Home-boiled gees lime-sulphur, lime-sulphur, lime-sulphur,| lime-sulphur, sprayed). Pi abs Ls ATO OOS. ce ae Sete eo Lk ets ead Oe oS | eee a | a ee a 1: Lee Senthil... ent oc ara tov ba eel irelwie te 6 4 3 5 Bes ae ieee eR A ese ae at NS 7 9 7 6 6: apse. Ulan. tech eR: aed me he 7 6 6 9 0S Raa a paige JOO CA Speed ct PE atl oe a RU oo” 1 Silo. ees ee SI Male hae apne Wet Mea eid, Sih Ty. S22 Oe ee | OCIS MS eee See ee eee Boab ee sce ace nha] ede Ss os Roe ae eo Bee eee Total number dead ..._... 6 20 20 20 20 Number of days required to kill |........ -._ | 9 | 12 12 9 Square inches of foliage consumed. 116.00 | 1.19 | 1. 28 3.05 4.38 | | It was found that the commercial and the home-boiled lime-sulphur killed all the larve in the same average length of time. However, the rapidity of killing was slightly greater, and the amount of foliage consumed less, where the commercial material was used, due probably to the fact that the commercial solution was somewhat stronger, which the Baumé tests would indicate. EXPERIMENT VII. Lime-sulphur, 14-50, was tried out on a limited number of pear- slug larve (Hriocampoides cerasi L.), since only a few were available for this test. As in all the experiments, the insects were not placed upon the leaves until the spray had thoroughly dried. The results are shown in Table VII. LIME-SULPHUR A STOMACH POISON FOR INSECTS. 89 TaBLE VII.—Tests of the killing effect of ae cine on the pear slug (Eriocampoides cerast L.). {Experiment started Aug. 24, 1912, Benton Harbor, Mich., 6 larve in each lot.] Larvee dying in each lot. Date of pee sation. Lot 2 (6 | Lot 3 (6 Lot 1 (6 larvee)—Check | larvee)—Lime- | larvee)—Lime- (unsprayed). | sulphur, 13-50. | sulphur, 14-50. PR ee ee een, Uo ORE « ole deere en nee Bile 1 och at ic a a A 2 4 si oo Oe Oe Se eer 1 2 PORE eae. AS) 4 .e see ade. fe bee RR de Pp ree SS BS Peale oe Gok ee ae Total number dead... 0 6 6 Number of days required to aM ee PL ee [hw ooh nes kclng oh 3 3 Square inches of foliage Consumed = 22 te. 1. 69 0. 08 0.05 Three days were required to kill all the larve on the sprayed lots. At the end of five days, when the experiment was closed, the larve on the unsprayed lot were apparently in a normal condition. MISCELLANEOUS TESTS. Preparations were made to conduct a number of feeding experi- ments on the killing effect of lime-sulphur on the second brood of codling-moth larve (Carpocapsa pomonella L.). But since a suffi- cient number of larve was not obtainable, owing to the small size of this brood appearing in Michigan, no satisfactory tests could be made. Neither were there any tests with lime-sulphur alone made against this insect in the field. However, in the case of a plat of Ben Davis apples, sprayed three times with lime-sulphur, 1-50, and 10 per cent kerosene emulsion, no arsenical being used, the total percentage of windfalls and picked fruit free from the codling moth was 90.18, as against 41.31 per cent of fruit free from this insect on the unsprayed plat. Lime-sulphur, 1-50, and fish-oil soap, 7 pounds to 50, without an arsenical, in the same orchard held the codling moth to 88.19 per cent of sound fruit. The effectiveness of lime- sulphur alone in controlling the codling moth and numerous other insects will be further tested during the season of 1913. A few laboratory tests were made of the killing effect of Bordeaux mixture, 3—4—50, on the fall webworm and about as effective results were obtained as from lime-sulphur solutions. Self-boiled lime-sulphur, 8-8-50, the preparation used for spraying peaches in foliage, was tried against the fall webworm without any killing effect. Sulphur alone, 8-50, and lime alone, 8-50, likewise were ineffective. 90 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. CONCLUSIONS. The foregoing tests of lime-sulphur wash against the larve of the fall webworm show that this preparation has decided value as a stomach poison. It is considered extremely probable that cater- pulars of many species of insects, and perhaps mandibulate insects in general, will be similarly susceptible. As shown by the data given, lime-sulphur, 14-50, while slower in killing effect than arsenate of lead, 2-50, nevertheless compares favorably with this strength of arsenical. A comparison, however, of leaf-areas eaten by larve subjected to lime-sulphur and arsenate of lead, respectively, shows that the lime-sulphur, especially at increased strengths, compares — quite favorably with the arsenical in reducing feeding by the cater- pillars. This action of lime-sulphur as a stomach poison probably accounts for the reported practical control of the codling moth in orchards treated with lime-sulphur alone, and furnishes an additional reason for its employment as a fungicide. ia Experiments in progress by the Bureau of Entomology during the past two years warrant the statement that entirely satisfactory results in controlling the codling moth in orchards may be obtained with lime-sulphur wash combined with reduced strengths of arsenate of lead. 7 ATION AL COPIES of this publication may be procured from the SUPERINTEND- ENT OF DOCUMENTS, Government Printing Office, Washington, D. C., at 5 cents per copy this ie e wane ag Seis Sait often see pet = 4 di ‘ ren + Na a 7 ‘Gas ‘ > . ly } er eee aA WLUE 4 ; c * ing peti , , CLE ia ne 4 onan ‘ay 5 x ' a alah a. i ye fy pets é MAMET 2 rox pe tapv naan weiss Psy oe Fol 9 A -* ‘ * , > la &. : m y = Put a eae >. rs ¥ ~ 2 bh \ . . , ‘ A i “ arn. v { ‘ y e J a a» ia dea" : ‘ " ry , ei Is ! & Rate Laue / N an ; ? 5 Ui nS F 3 Dre eee kh a A ; J = J te Be an re Ui I, a F a ’ r MEY ? ota % ‘ ’ -- ba Pir Y) 1. é : ? Sp ‘ _* ~S 2 a . rigs at A wed p r ) be 7 ¥ Fe ‘ he * . i} , % ¥ ) i ye, i Wy i { 1 . i “ ,, y hw we oe OE 4 [3 - . ne c\. "e y P é s VBA ’ } ¥ t ; > wie i y " - r ee 2 65, or ohag r f he . hy + oe nee . we > b = - ee ? % ee: ~ eo ais ri Ie ace , t j b y ) wr Be é Soo i ' . é = _ ) s # ‘ ‘ , ‘ fi Na 4 =! ~ ; f e axa e came ppp iaataie FF Fo Nae . in ey O57 9b Semele uae ~ ~ A ‘ , v , ge wet r. “ - #) « We , uy si (| ; ug . ~ 7 f a U / 'e ie ~ a ke : Ag " = Mn - ar tae - ‘ i on 7 ~ . 7 = 5 my } ' an a AN aR , ‘ ' AS, Pi, - Yan) * a ri J a -_ a *' iad - ‘ i J co" , os ke he re * PIV. INSECTS. Seer ART MENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN No. 116, Part V. L. O. HOWARD, Entomologist and Chief of Bureau. _ PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. THE FRUIT-TREE LEA F-ROLLER. BY JOHN B. GILL, Entomological Assistant. IssupED Marcy 12, 1913. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1913. BUREAU OF ENTOMOLOGY. L. O. Howarp, Entomologist and Chief of Bureau. C. L. Marzarr, Entomologist and Acting Chief in Absence of Chief. R. 8S. Cureron, Executive Assistant. W. F. Taster, Chief Clerk. . H. CHITTENDEN, in charge of truck crop and stored product insect investigations. . D. Hopxrns, in charge of forest insect investigations. . D. Hunter, in charge of southern field crop insect investigations. . M. WEBsTER, 1n charge of cereal and forage insect investigations. . L. QUAINTANCE, 1n charge of deciduous fruit insect investigations. E. F. Puiups, in charge of bee culture. D. M. Roacers, in charge of preventing spread of moths, field work. Rouia P. Currie, in charge of editorial work. MasEL COLcorD, in charge of library. Decipvovus Fruit Insect INVESTIGATIONS. A. L. QUAINTANCE, 1n charge. FRED JOHNSON, F. E. Brooks, A. G. Hammar, E. W. Scort, R. L. Novearet, R. A. CusHMAN, L. L. Scott, J. B. Gm, A. C. Baker, W. M. Davinson, E. B. BLAKEs- LEE, W. B. Woop, E. H. Stecuer, F. L. Stmanton, entomological assistants. _ J. F. Zimmer, W.S. Aszort, W. H. Srtx, entomological assistants, employed in enforce- ment of insecticide act, 1910. II ere ee SY, Page TENE Sa es 2 yg OL i wk a gap aw bade eden sae 92 rer se LS SE Te ek hee A ee 93 eunnnrmramncas tert ti. FAL) NS: ee ge. sok ee 93 METI fs 2 02S oe. eat Laie. Seas. eek ee. 2! 94 a i hay Rae ge La cn al ny wy (a Sw cepe lw San be ee pee 96 ec hg A Pee Se ola ate Ae ee ee 96 ene Sree h) LEO. Oost. DSO. LO IY OUP. mers. AL a. 96 en vi SLED NL POCA NS LOO POI sierL OE 96 ee niate eu og oS el wre 97 ECT (eo a a ee ee a 97 I ES ere ey ee eee Se a a be ae ee 97 ren sare. IL BO. IASG He IVIL BOR. SOMO ool oy. 98 MEAN OPO RLAOES... oslo. aaese ss ece orcas seeie YL OYE... 99 memtenmen mele Wistory 25.50) 502 20) Soler Sore ee stele Le, 101 MEE 30) 5254s 5 249 Pas Sos tee sess WERE iy SPOIL 101 Tne Pes. SU TSE) AIL 20 BSG LRG BOI ek LE le, Ett 102 ER MREIIING S250. oe 2). oe RI Ey JO EE od de 102 Experimental tests for the destruction of the eggs...............-...-.---- 108 Spraying experiments for the destruction of the egg-masses............-..- 104 pemmnmenia at Pspanola, N. Mex........-...--..-----2---2 ee 104 Memories at Canon Ciby;'Colo...20..-..-..0..2.----0 bee e eee 105 Spraying experiments against the larve...............--------------+---- 106 I Sever hd ao ciag cd otras Peter. 4 ehh AP pga ~ ese ese ale wn «pawn 107 a AE eR AI te Monte as Snins ed min ww See 108 GES a ne 109 LLL STR LO PLATES. PuaTe XII. Stages and work of the fruit-tree leaf-roller (Archips argyrospiia). Fig. 1.—Hatched egg masses on apple twigs. Fig. 2.—Full- erown larva. Fig. 3.—Pupez. Fig. 4.—Cocoon and pupal case. Fig. 5.— Young apples injured by larve .............-2.....-- XIII. Work of the fruit-tree leaf-roller. Fig.1.—Apple branch, showing webbing and injury to foliage by larve. Fig. 2.—Apples in- jured by larvee Do s0e2. 2... - 226. + 2.5252 +. eee eee ee eee XIV. Apple orchard at Canon City, Colo., defoliated by the fruit-tree leai-toller 2 nan ce eiee pie gee cies. ine as os ae ee XV. Excessive webbing by larve of the fruit-tree leaf-roller.......... XVI. Stages of the fruit-tree leaf-roller. Fig. 1—Egg masses on trunk of apple tree. Fig. 2.—Moth and extruded pupal case. Fig. 3.—Unhatched egg masses on apple twigs..........-.---+.--- Iv Page. 94 94 94 94 98 ] U.S. D. A., B. E. Bul. 116, Part V. D. F. Iv 1., Issued March 12, 1913. PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. THE FRUIT-TREE LEAF-ROLLER. (Archips argyrospila Walk.) By Joun B. Gr, Entomological Assistant. INTRODUCTION. Until quite recently the fruit-tree leaf-roller (Archips argyrospila Walk.) has been looked upon as an insect of only minor importance to cultivated crops. During the past few years, however, it has become unusually abundant and has caused considerable loss to fruit growers in certain sections, notably in Colorado and New Mexico and in New York State. The most serious outbreaks have appeared in Colorado in Fremont, Pueblo, and Montezuma Counties, and in New Mexico in San Juan and Rio Arriba Counties. The investigations, detailed in this paper, have been confined for the most part to the infestations at Canon City, Colo., and Espanola, N. Mex. In the former place the damage has been large, as the insect has appeared in serious numbers in about 1,500 acres of bearing orchards in what is locally known as the Lincoln Park section, and it is also spreading rapidly into adjacent fruit districts. If not checked the amount of loss that will be occasioned by its attacks in the future will probably be much greater than in the past. At Espanola, N. Mex., a com- paratively small fruit belt, the infestation has not been so serious. The damage incurred by the leaf-roller has varied from 25 to 90 per cent of the entire fruit crop, depending on the measures of control adopted, the abundance of the “worms,” and the kind or variety of fruit attacked. In unsprayed.orchards the writer has seen the entire fruit crop ruined by the larve, and the trees completely defoliated so that not a green leaf could be noticed. When trees are so defoli- ated it is hardly possible for them to produce fruit buds for the fol- lowing season. In speaking of the appearance of the fruit-tree leaf-roller in New York Prof. G. W. Herrick says: In the spring of 1911 the larve of this insect appeared in enormous numbers in the orchard of Mr. W. O. Page at Bethany Center, N. Y., and to a considerable extent in neighboring orchards. Moreover, the apple leaf-roller was not confined by any means to a small and limited area, but the larvee were found in many orchards of New York in varying numbers. 91 92 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. A few years ago the Missouri fruit growers suffered considerable loss on account of this same leaf-roller. Because of the increasing economic importance of this insect the Bureau of Entomology started investigations in 1911 at Espanola, N. Mex., with which work the writer was charged, under the direc- tion of Mr. A. L. Quaintance. During the season of 1911 little was accomplished owing to the stress of work along other lines in fruit sections that were not troubled with the leaf-roller. On account of the seriousness of the outbreak at Canon City, Colo., it was decided to maintain a temporary field station at that place during 1912 for conducting orchard spraying experiments and life-history studies of the msect. The investigations during this time have shown the value of certain practical measures for the control of this pest, and have resulted in the obtaining of considerable data on its life history. The object of the present publication is to give as much information as is now available about the leaf-roller and methods for its control. The writer wishes especially to thank the orchardists of Colorado and New Mexico who have assisted in this work. HISTORY. The fruit-tree leaf-roller was first described by Walker in 1863 under the name Retinia argyrospila, from material collected in Geor- gia. In 1869 it was first recognized in this country by Robinson as doing damage, and was redescribed as a new species, Tortriz furvana. The following year (1870) Packard described it as a new species, naming it Tortriz v-signatana and giving its distribution as ‘ Maine to Georgia and Texas and Missouri,” and its food plants as black walnut, maple, cherry, and horse-chestnut. Packard also gave a description of its life history and food plants in the Fifth Report of the United States Entomological Commission, pages 192, 195, 329, 425, 530, and 655. In an article in Insect Life, Volume III, page 19, by Riley and Howard, this species is mentioned as a rose pest. Lintner included it in his Eleventh Report of the State Entomologist of New York (1896) as one of the 356 species of insects that were enemies of the apple. Gillette, in Bulletin No. 26 of the Division of Entomology, United States Department of Agriculture (1900), men- tions it as a general feeder, and in the Thirteenth Annual Report of the Colorado Experiment Station (1900), page 123, it is also men- tioned. In Bulletin No. 27 of the Division of Entomology (1901), page 88, Chittenden refers to it as affecting the rose. Holland, in ‘The Moth Book,” page 422, plate 48, fig. 34, discusses this species, and it is included in Dyar’s List of North American Lepidoptera, page 480, with its distribution lmited to California and Colorado. In Bulletin No. 38 of the Division of Entomology, page 36, Mr. A. N. Caudell gives an account of it as infesting ash in Colorado. Horsfall, ee oF THE FRUIT-TREE LEAF-ROLLER. 93 in Bulletin No. 9 of the Missouri State Fruit Experiment Station, ~ page 22 (1903), states that it was very destructive in 1901. In Bul- letins Nos. 94, pages 9-11, and 114, page 7, of the Colorado Experi- ment Station, Gillette again discusses this species. The most com- plete account is by Stedman in Bulletin No. 71, Missouri Agricultural Experiment Station. In the last edition (1909) of ‘‘Insects of New Jersey,’’ by Smith, it is included and mentioned as a very general feeder throughout the State. An article by Herrick appeared in the Rural New Yorker, March 2, 1912, page 263, in which it was discussed as a ‘‘new pest of the apple in New York.” The same writer, in Bulletin 311 of the Cornell University Agricultural Experiment Sta- tion, gives a full account of the species, as based on its occurrence in New York State. The above includes all the important articles on this insect, se far as the writer has been able to determine. DISTRIBUTION. The fruit-tree leaf-roller is generally distributed throughout the United States. Stedman, in Bulletin No. 71 of the Missouri Experi- ment Station, page 7, states that ‘this insect is found in damaging numbers practically all over the United States from Maine to the Gulf and westward to the Pacific coast and up as far as Oregon.” Packard, in 1870, gave its distribution as “Maine to Oregon and Texas and Missouri.’’ Holland gives its range as “Atlantic to Pacific.”’ So far as the writer has been able to determine from litera- ture on hand, the species has been definitely recorded from New York, New Jersey, Georgia, Missouri, Texas, Colorado, and California. The writer reports it in New Mexico from Espanola, Santa Fe, and Taos. It is also reported from Riverside, N. Mex. In Colorado it is recorded from Canon City, Vineland, Avondale, Cortez, Olathe, Fort Collins, Brewster, Penrose, and Garden Park. The writer has been unable to get a list of specific localities for other States. Although widely distributed throughout the United States, it ranks as a pest at the present time in only a few localities in Colorado, New Mexico, and New York, where conditions seem to have been favorable, for some reason or other, for it to appear in enormous numbers. FOOD PLANTS. The insect is a very general feeder and consequently has been reported on a large number of plants. It appears at times in injuri- ous numbers on apple, pear, plum, cherry, apricot, quince, peach, rose, currant, raspberry, and gooseberry. It has also been recorded feeding more or less on black walnut, horse-chestnut, soft maple, hickory, oak, elm, wild cherry, ash, honey locust, box-elder, sassafras, 94 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. hazelnut, and osage orange. In addition to the above the writer has observed the larve feeding on grape, blackberry, cottonwood, Caro- lina poplar, basswood, cedar, lilac, Virginia creeper, snowball, hop- vines, and oats, wheat, alfalfa, red clover, onions, peas, beans, radishes, and rhubarb that were growing in or adjacent to badly infested orchards. This species appears to be able to thrive on the ’ foliage of almost any plant. CHARACTER OF INJURY. As the manner in which the larve attack the various host plants differs to a certain degree, it seems advisable to give a rather full dis- cussion of the more important injuries, especially those occurring on fruit trees. | In the spring, just as the buds are bursting, the larve begin to gnaw their way out of the eggshells and hard protective covering of the egg masses. (Pl. XII, fig. 1.) The young caterpillars at once migrate to the developing buds and begin feeding on the unfolding leaves. At first they eat small inconspicuous holes in the unfolded leaves, and at this time the average orchardist is not aware of their: presence. After feeding in this manner for a few days the larve be- come quite conspicuous as they begin to spin fine silken threads from leaf to leaf. Eventually they fold or roll up a single leaf or a cluster of leaves and here they feed for the greater part of the time, though occasionally straying out of their concealment to feed in the open. (Pl. XIII, fig. 1.) Before the blossoms are fully out, or even before the cluster buds have separated, the ‘‘worms’’ can be observed webbing them together and feeding voraciously. Very often serious injury results before the trees come into blossom. Later in the season the webs produced by the larve are often quite conspicuous, as is shown in Plate XV. As soon as the young fruit has set the larve cease feeding on the foliage to a large extent, and now fasten one or more leaves to the fruit and within this protection feed greedily, at first eating the skin only, but shortly consuming the pulp and the seeds or stone, depend- ing on the kind of fruit attacked. (Pl. XIII, fig. 2.) Sometimes © young apples are completely devoured except for the stem and a portion of the calyx end. Cases have been noticed where the larvee have completely gnawed through the stems, thus causing the fruit to fall to the ground or remain suspended within the feeding nest. Damage done to apples as well as other fruits is usually so severe that the fruit can not outgrow the injury, thus causing a large percentage of unmerchantable or second-class fruit at picking time. Much fruit is also caused to fall prematurely on account of the serious injury inflicted on it when young. The writer has seen several orchards Bul. 116, Part V, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XIl. STAGES AND WORK OF THE FRUIT-TREE LEAF-ROLLER (ARCHIPS ARGYROSPILA). FiG. 1.—HATCHED EGG MASSES ON APPLE TWIGS. Fi@. 2.—FULL-GROWN LARVA. FIG. 3.— PuPA. Fia. 4.—COCOON IN APPLE LEAF AND Empty PupaL CASE. Fic. 5.—YOUNG APPLES INJURED BY LARVA. FIGs. 1, 2, 3, MUCH ENLARGED. (ORIGINAL.) Bul. 116, Part V, Bureau or Entomology, U. S. Dept. of Agriculture. PLATE XIII Fig. 1.—APPLE BRANCH, SHOWING WEBBING AND INJURY TO FOLIAGE BY LARVA. (ORIGINAL. ) Fic. 2.—APPLES INJURED BY LARVA. (ORIGINAL.) WORK OF THE FRUIM-TREE (EEAF-ROEEER: Bul. 116, Part V, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XIV. * Lay e * ba (ORIGINAL.) APPLE ORCHARD AT CANON CITY, COLO., DEFOLIATED BY THE FRUIT-TREE LEAF-ROLLER. Bul. 116, Part V, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XV. EXCESSIVE WEBBING BY LARVA: OF THE FRUIT-TREE LEAF-ROLLER. (ORIGINAL.) THE FRUIT-TREE LEAF-ROLLER. 95 at Canon City, Colo., where the entire apple crop was absolutely ruined and where the larve had defoliated the trees so completely that not a green leaf could be seen. (PI. XIV.) At Espanola, N. Mex., fully 75 per cent of the fruit crop in certain apple orchards has been destroyed by these leaf-roller “worms,” which have besides caused serious injury to the foliage. Similar conditions have been seen at Vineland and Avondale, Colo. The injury to pears is quite similar to that of the apple, but not so extensive. The writer, in talking with orchardists at Espanola, N. Mex., in reference to the amount of injury to pears that had been sprayed twice with arsenate of lead, was informed that one-fourth to one-half of the crop was damaged to such an extent that it could not be packed. Even a very slight feeding on the pear when young often results in an il-formed specimen when mature. Pear trees are not usually defoliated by the leaf-roller, even if not sprayed. The writer has, however, observed a few instances where they were completely defoliated in a very badly infested district. : In case of stone fruits, such as plum, apricot, and cherry, much of the pulp, as well as occasionally a part of the stone, is eaten, except with the cherry, which seems to escape injury to the seed. Cherry and plum trees are sometimes entirely defoliated. According to reports from Riverside, N. Mex., during 1909 and 1910 the entire peach crop was destroyed by this pest. During the past two seasons the writer has failed to find a single instance where a peach orchard has been injured very much. The nature of the injury to the peach is a slight feeding on the surface, and the larve seem never to have eaten into the pulp as far as the stone. The injury on small fruits, such as raspberries, currants, goose- berries, etc., is often quite serious, as the larvee not only feed on the foliage but also eat into the fruits. The larvee occasionally feed on the foliage of the grape. Of the shade and forest trees that are attacked the worst injury usually results on the elm, on which the leaves are often badly eaten. The damage noticed on truck crops, oats, wheat, alfalfa, and red clover has been a slight feeding on the leaves. ‘The larvee, however, on one occasion were noticed eating their way into the tops of onion plants that were growing between rows of apple trees that had been defoliated by this species. Another case at the same place was noticed where a small cedar tree was nearly stripped of its leaves by these larve, and the tree was covered by webs. Roses are seriously injured at times, as the larve not only feed on the foliage but gnaw into the flower buds and prevent their proper development. 67331°—Bull. 116—13——2 96 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. DESCRIPTION OF STAGE Ss. THE ADULT. This leaf-roller was first characterized and named in 1863 by Walker in the Catalogue of the British Museum, volume 28, page 373, as Retunia argyrospila. The original description is as follows: Female. Reddish, cinereous beneath. Head ochraceous; palpi porrect, broad, extending very little beyond the head; third joint extremely short. Abdomen cinereous, extending a little beyond the hind wings. Forewings rectangular at the tips, with several transverse slightly undulating black streaks; space along the interior border and some incomplete irregular bands silvery cinereous; costa straight, with three large silvery white marks, exterior border slightly oblique hindward. Hind wings brownish cinereous. Length of the body 34 lines; of the wings 10 lines. a. Georgia. From Mr. Milne’s collection. The moths measure from 17 to 23 mm. across the expanded wings. The length of the body varies from 8 to 10 mm. There is a wide variation in color. The general color of the forewings varies from a light brown to a cinnamon or rusty brown. The markings on the forewings also show a variation in size, pattern, and color. Ordinarily each forewing has three whitish markings. The hind wings are without markings and are of a uniform ashy-gray color. (Pl. XVI, fig. 2, at left.) THE EGG. The eggs are deposited in sightly convex, oval masses or patches which vary in color from a light gray to a dark brown. The egg masses are covered by a hard protective coating. The size of the masses is variable. The average for 20 was found to be 5.1 by 2.6 mm. ~ The average number of eggs per mass is about 90. The individual ege is quite small and is a little more than twice as long as wide. The eggs are packed in the mass very tightly. A longitudinal section of an entire egg mass presents a honeycombed arrangement. (PI. AAT; he. 1s PL VE fies: d,-30) THE LARVA. When newly hatched the larva measures about 1.5 mm. in length and is pale yellowish green, with the head and thoracic shield dark brown or nearly black. At this time the thoracic legs are nearly black, while the prolegs are of the same general color as the body. As the larva develops the color of the head, thoracic shield, and legs gradually changes to a light brown and the body takes on a darker shade of green. Before pupating the thoracic shield and legs of the larva take on an olive-green tinge, slightly darker than the rest of the body, which is now a light green. The larva is sparingly clothed with short hairs, which arise from rather inconspicuous tubercles. The full-grown larve measure from 16 to 23 mm. in length and from 2 to 2.2 mm. in greatest width. The average size for 10 larve was found to be 20.3 by 2.04 mm. (Pl. XII, fig. 2.) THE FRUIT-TREE LEAF-ROLLER. 97 THE PUPA. The pupa is rather variable in size. The average dimensions of 10 pupe were found to be 10.3 by 3.1 mm. The general color of the pupa when first formed is an olive green, but later changes to a light brown and finally to a dark brown. The entire ventral surface, including the head and thoracic regions, is of a dark-brown color and the remainder of the pupa is of a much lighter brown. The wing sheaths are rather broad, extending about one-half the total length of the pupa. Just ventral to the spiracles on each side of the abdo- men are two short sete. On each abdominal segment, from the third to the last, on the ventral portion is a pronounced chitmous serrated ridge. The second abdominal segment has traces of one of these ridges. The posterior end of the pupa is supplied with a well- developed cremaster. (Pl. XII, fig. 3.) LIFE HISTORY AND HABITS. The life-history records were obtained at Canon City, Colo., during the season of 1912 in an open-air insectary or shelter in which glass jars were used as rearing cages. In all cases apple foliage was used as food for the larve. LARVAL STAGE. The hatching of the larve extended over a period of 12 days. The earliest larvee hatched April 27 and the latest ones on May 9. As soon as the larve hatch from the eggs they gnaw their way through the protective covering which the females deposit over the egg masses during oviposition. The duration of the larval period showed a considerable variation. Thenumber of days spent in the larval stage for 203 individuals is shown in the following table: TaBLE 1.—Length of larval stage of the fruit-tree leaf-roller, Canon City, Colo., 1912. | Number Larve pupating in specified days from time of hatching. | of larvee pe UTS Date | under ob- pee | PS al Fa chil “oehpliin . | : | | Total atched. | that trans-| . : a SP eal | ie num- formed to 24 | 25 : 26 | 27 | 28 | 29 | 30} 31 | 32 | 33 | 34] 35 ber of pupe. | days 21 . ‘| Be Ree chiccoteaes Re Bey We a yee ee 0 Oe SR eae A Ea MS Be oe oe ee a ea ee Sete BS Db |. hb ee BW | ehake ce paso ies gr a aioe | 8 | Wie achs. .|.... OR RR os | rg ee OMe Ee Se ee pc p+ Pies Meal”: 3 2 SR PRE SS Or ol ees 1 Te Ol a Leet a ee he ET MOE tone) Retr el a ah RP es a a Rg RYRRE ee EST IM PRE TL Wk bebe le eels oxo bi Ale «bb fas oer tnhde ok a a a ca a ang 5, FIR Dan ORS Ht ae es 203 | 6 | 23 | 44 | 30 | 15|29/17/11| 4] 3] 1] 5,696 3% Average time for all individuals, 28.05 days. 98 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. The time required for the larve to reach maturity was determined for 203 individuals, as is shown in Table I. The average time for all larvee was found to be 28.05+ days, the maximum being 35 days and the minimum 24 days. The length of the larval period for 1912 was doubtless longer than during a normal season. The weather conditions that prevailed throughout the spring of 1912 were to some degree exceptional. During the larval development from May 4 to 17, inclusive, the weather was exceptionally cool, the maximum temperatures for these days ranging from 38° to 76° F. ; In the rearing cages the larve, when full grown, invariably trans- formed into pupe in the Poliedeae leaves upon which they had been feeding. In afew cases larvee were seen pupating on the bottom of the cages. In the field larve usually change to pupe in the rolled-up leaves. In a few instances they have been observed making the transformation on the bark of the trees, where no protection was afforded the pupe. PUPAL STAGE. The length of the pupal period for 128 individuals is — in the following table: TasLE I1.—Length of pupal stage of the fruit-tree leaf-roller, Canon City, Colo., 1912. Moths emerging—in specified days | Number from date of pupation. / of pup Date under ob- larvee servation pupated. |from which otal moths 9 | 10) 11 | 12) 13) 14) 15 Hering emerged. days May 28 6 DLs RAL pie eee hayes al a ae ape etna May 29 6 Dye eit Wie el aa ee Cl ee May 30 VU 2 Real Outer cay |e v2) || 1s ese | aoe see May 31 TOM she GB 585 rt a eee ee June 1 5 2 1 Diol Pe rs See Oe Ef eee ee ee June 2 (al ee es) a ees Sai ee | June 3 HUE ey eas a OATH esa (I He aL Re a | June 4 15 2 4 5 2 1 AD She Fee | see aa June 5 UO We SSA Al ital ae, 3 2 ipl acne cps t.< June 6 HO) We des 7 Vea Sp Dada Uae | June 7 ile BPs) oes (ren ee eee Be Sie ty June 8 4 Ble PL Ao © ANA Soe ee June 9 3 | 25,09 Mall) fc 208), eee et ee sya June 10 3 | eae Pll Ai ee ha Ea e's sll ABS SS June 13 7 Sil eA ete nil oe 2 eee ene | 128 | 8 | 27 | 46 | 28 | 12 5 2 | 1,440 | ! | Average time for all individuals, 11.25 days. The earliest larvee to pupate were observed on May 28, and the latest ones on June 13. The days spent in the pupal state varied from 9 to 15 days, the average for 128 individuals being 11.25 days as is shown in Table II. Bul. 116, Part V, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XVI. STAGES OF THE FRUIT-TREE LEAF-ROLLER. Fic. 1.—EGG MASSES ON TRUNK OF APPLE TREE. FIG. 2.—MOTH AND EXTRUDED PUPAL CASE. FIG. 3.—UNHATCHED EGG MASSES ON APPLE TWIGS. FIG. 1, MUCH REDUCED; Fics. 2, 3, MUCH ENLARGED. (ORIGINAL.) THE FRUIT-TREE LEAF-ROLLER. 99 In the orchard the first pupx were observed on June 1 and the maxi- ~ mum period of pupation was reached from about June 12 to June 20. Pup could, however, be found in the field as late as July 10. Just before the emergence of the adult the pupa wriggles out of its loosely woven cocoon (PI. XII, fig. 4; Pl. XVI, fig. 2, at right) for a short distance. The posterior end of the pupa is provided with three pairs of hooks, which are known, as the cremaster, and these hooks become fastened to silken threads that have been spun by the larva on the leaf, so that the pupa is held securely, even if the greater part of the body is extended. While the writer was examining rear- ing cages on July 3 (8 a.m.), a pupa was noticed wriggling out of its pupation quarters. The following observations were made: 8.20 a.m. The pupal skin or shell was cracked in the anterior region. 8.25 a.m. Moth about half out. 8.30 a. m. Moth left the pupal shell, the body being still wet and the wings quite wrinkled. 8.35 a.m. Body dry and wings straightened out and folded over back. 8.43 a.m. Wings have separated and are held roof-like over the back, 8.55 a. m. Moth crawling about in glass jar quite actively. 8.58 a. m. Observations ceased; moth was fluttering about the cage. Total time consumed in emergence, approximately 10 minutes. It will be noted that the time required for this moth to emerge after the breaking of the pupal skin was about 10 minutes, and in- side of five minutes after emergence its body and wings were dry, but the moth did not become active until about 20 minutes had elapsed. THE ADULT AND EGG STAGES. From material under observation the first moth emerged on June 7 and the latest ones appeared on June 24. The maximum emer- gence of moths was on June 14 and 15. In the field the period during which the greatest number of moths appeared was from about June 22 to July 1. The first moth was noticed in the orchard on June 9, and by July 20 practically all moths had disappeared. From about June 25 to July 10 most egg masses were being deposited on the trees. The following egg-laying records were obtained in rearing cages, and these have a direct bearing on the length of life of the moths. On June 21 at 8 a. m. a male and female that had emerged during the previous night were placed in a jar in which was put a small twig, so that there would be a suitable place for oviposition. The cage was examined on June 22 and both moths were quite active. On June 23 at 5 p.m. the male moth was found dead in the bottom of the jar, but the female was actively crawling about in the cage. At 8 a.m. the next day (June 24) a medium-sized egg mass was deposited on the twig. The moths were not observed copulating. The eggs 100 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. had been laid some time during the interval between 5 p. m. on June 23 and 8 a.m. on June 24. The female was dead on June 25 (8 a.m.). The female lived for about four days and the male only about two days. Eggs were deposited in two and one-half days. On July 1 (8 a. m.) a male moth and a female moth just emerged were placed in a jar with an apple twig. Food was furnished the pai of moths by supplying them with a piece of absorbent cotton which had been saturated in a weak solution of sirup. The. cage was examined the next day at 9 o’clock and both moths were quite restless. On July 3 at 8 a. m. an egg mass was found on the twig and both moths were still active.. The male had died by 9 a. m. on July 4 and the female by 8 a. m. on July 5. Copulation was not observed. In this case the male lived about three days and the — female about four days. The eggs were laid inside of two days after emergence of the moths. | On July 16 two moths were_-observed mating and at noon were put in breeding jar. The cage was again examined on July 17 and the moths had ceased copulating and were crawling over the sides of the jar. On July 18 at 4 p. m. the cage was again looked over and an egg mass was found deposited on the twig. The life of the moths could not be determined, as the time of emergence was not known. A period of about two days is shown between the time of copulation and the time of deposition of the egg mass. There are not sufficient data bearing on the length of life of the adults to justify any generalization. The writer believes there is a wide variation in the longevity of the moths and that the females usually outlive the males. It is also reasonable to expect the moths to live for a longer period under natural conditions than is the case when they are kept in confinement. It is also likely that the females do not oviposit out of doors as readily as when confined in rearing jars with the males. Observations under insectary conditions go to prove that the female if left unmolested during oviposition deposits all her eggs ina single mass. All ege masses deposited in rearing cages consisted of more than 100 eggs, the greatest number from one female being 140. In the orchard it is not difficult to find rather small egg masses. The smallest one observed was composed of 25 eggs. In making field observations the writer noticed that the female when oviposit- ing would cease the operation very readily if disturbed in any way and fly or crawl away. Ovipositing females were observed changing position when insects such as ants, ground beetles, and ladybird larve or adults came too near them. One species of Coccinellidz that is especially predaceous on the green aphis of the apple was noticed several times disturbing females in the act of oviposition, compelling them to crawl or fly to another place to deposit the THE FRUIT-TREE LEAF-ROLLER. 101 remainder of their eggs. This restless habit of the females may account for the many small egg masses that are found in the orchard. ‘The eggs are usually laid at night. Moths have, however, been seen laying eggs as early in the evening as 5.30. SUMMARY OF LIFE HISTORY. The larval stage in the material under observation varied from 24 to 35 days, the average being 28.05 days; the pupal stage from 9 to 15 days, the average being 11.25 days; and the adult or moth stage from 2 to 3 days for the males and 3 to 4 days for the females. The life of the moths is probably longer than this under normal condi- tions. Females were depositing eggs between 2 and 3 days after emergence. In the field (under Colorado conditions) the period of egg laying extended from about the second week in June to the middle of July, the maximum being reached from June 25 to July 10. The eggs remain on the trees unhatched until the followmg spring. Hence this insect has only one generation in the course of a year. The hatching of the eggs m the sprig may extend over a period of many days, depending on the weather. The time of hatching of the eggs will vary greatly with the different seasons and in different sections of the country. Generally speaking, it may be stated that the eggs will begin hatching about the time the cluster buds of early- blooming varieties of apples are beginning to show, but before they have fully separated. HIBERNATION. The fruit-tree leaf-roller passes the winter in the egg stage. The eggs are deposited in masses on various parts of the host plants by females during June or July. The trunks and larger limbs or branches are often just ‘‘peppered”’ with them. A goodly number are also to be found on the smaller branches, twigs, and fruit spurs. Egg masses are, however, not only laid on fruit trees, but on various other plants. The writer has observed them on elm, soft maple, box-elder, currant, gooseberry, raspberry, grape, rose, lilac, and Virginia creeper. Besides the above plants, the masses have been noticed on spray tanks, on sides of buildings, and on fences. On account of the indiscriminate deposition of its eggs this insect will be found to be more difficult of control. Observations have shown that the eggs begin hatching quite early in the spring just as the cluster buds on early blooming varieties of apples are exposed. About the time that practically all the cluster buds have fully separated nearly one-half of the eggs have hatched. On late-blooming varieties of apples, such as Rome Beauty, Jeniton, etc., the date of appearance of the larve is the same, although the buds are not nearly so far advanced. On Rome Beauty and Jeniton 102 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. trees it was found to be a much harder problem to do as effective spraying with arsenicals as on Jonathan, Ben Davis, Maiden Blush, and other varieties that developed their buds early. If the fruit and leaf buds are not much advanced it is very difficult to get the spray mixture where the larve are actually feeding. The period of hatching of the eggs may be quite prolonged, depending on climatic conditions. During the season of 1912, in the orchards, the eggs were hatching from April 20 to May 9, making a period of 19 days. It should, how- ever, be noted that weather conditions were exceptionally cool after a short warm spell during which the eggs began to hatch. Under more favorable conditions all eggs would aan hatch inside of a week or ten days. On account of the long hatching period spray against the larvee was found to be very difficult. NATURAL ENEMIES. Several species of birds have been observed feeding upon the larve of the fruit-tree leaf-roller. The lst is as follows: The bluebird (Sialia sialis), western robin (Planesticus mgratorwis propinquus), catbird (Dumetella carolinensis), red-winged blackbird (Agelaius pheniceus pheniceus), orchard oriole (/cterus spurius), kingbird (Tyrannus tyrannus), phoebe (Sayornis phebe) and English sparrow (Passer domesticus). The writer has reared a number of parasitic insects from the larvee and pupee of the leaf-roller, as follows: Pimpla pedalis (Cress.), Ito- plectis conquisitor (Say), Epirus wmdigator (Walsh), and Meteorus archipsidis Vier.; the latter is the same species as that reared from this host by Mr. R. W. Braucher at Bethany Center, N.Y. The fol- lowing Diptera also were reared from this host: Exorista ngripalpis Towns., E. pyste Walk., EL. blanda O. S., and E£. chelonre Rond. A few insects were found to be predaceous upon the fruit-tree leaf- roller. Calosoma scrutator was taken feeding on the larve and Notozus monodon Fabr. was collected at two different times feeding on the pupe in rolled-up leaves. Formica montanus Emery has also been seen attacking the larve and pupe. A small mite, which Mr. Nathan Banks considers to be a new spe- cies of Erythrzus, was found feeding upon the eggs cf the leaf-roller. The mites belonging to this genus are said to be always predaceous, and some of them feed on scale insects. METHODS OF CONTROL. During the winter of 1911-12 and the spring of 1912 many experi- ments were made at Espanola, N. Mex., and Canon City, Colo., against the fruit-tree leaf-roller. The experimental work will be taken up separately according to the locality in which it was conducted. THE FRUIT-TREE LEAF-ROLLER. i 103 ee ‘EXPERIMENTAL TESTS FOR THE DESTRUCTION OF THE EGGS. Many laboratory tests were made for the destruction of the eggs. Only egg masses deposited on twigs were used, and these twigs were dipped in the various mixtures employed. After treatment the masses were kept in separate jars. in Table IIT. The results of the test are shown TaBLE III.—Tests of sprays for the destruction of eggs of the fruit-tree leaf-roller. No. of Date of ex- Material used. applica- peri- tion, 1912. ment. ey Maserbre o1l'(1:12). 2... . Jan. eo Pavenmscibe OU (L=15),. oo... se hes Sl eesciple OC: 20). 022... do: 4| Miscible oil (1:10)......... 2 1d0% 5 | 25 per cent kerosene emul- |...do. sion. 6 | 20 per cent kerosene emul- |...do. sion. 7 | 25 per cent crude petro- |...do. Jeum emulsion. 8 | 20 per cent crude petro- |...do. leum emulsion. 918 per cent distillate-oil |...do. emulsion. 10| 5 per cent distillate-oil |...do. emulsion. 11 wire ae lime-sulphur |...do. 12 ae lime-sulphur |...do. 13 oa lime-sulphur |...do. 14 ea lime-sulphur |..-.do. 15 oa lime-sulphur |...do. Fl) 16 | Check—untreated (caged) .|...do.... 17 | Miscible oil (1:12)......... Mar. 5 , 18 | Miscible oil (1:15).........)... Oe sei 19.} Miscible,oil (1:18).........|... GON... 20 | 25 per cent kerosene emul- |. ..do. sion. 21 | 20 per cent kerosene emul- |. ..do. sion. 22 | 25 per cent crude petro- |...do. leum emulsion. 23 | 10 per cent distillate-oil -- AO, emulsion. 24 | Check—untreated (caged) .|...do... . 25 | Miscible oil (1:12)......... Apr. 14 26 | Miscible oil (1:15).........]... do. Bue wvarireweani--..°-.........|.-- aos... 28 | Check—untreated (caged) .|...do... - Number ot Number of egg ae of egg masses ane masses treated. harched. hatched. 10 10 0 10 10 0 10 HOM oct es 5 Sah Pacem Seve 10 9 1 10 10 0 5 5 0 5 4 1 5 5 0 5 0 5 10 0 10 | 5 0 5 5 0 5 5 0 5 5 0 5 5 0 5 ey 15 0 15 14 1 15 15 0 10 10 0 10 9 1 9 7 2, 10 10 0 10 0 10 86 84 2 122 119 3 25 0 25 113 0 113 Remarks. 3 eggs in mass hatched. ~ 12 eggs in mass hatched. Most all the eggs hatched. Practically all eggs hatched. All egg masses hatched well. Only 1 egg hatched. 6 eggs in mass hatched. 7 eggs in 2 masses hatched. All eggs hatched well. 1 egg in each mass hatched. 7 eggs in 1 mass hatched; about one-fourth total eggs in 2 masses hatched. Practically all eggs hatched. 107 masses hatched well; about one-half total eggs hatched in 6 masses. It will be noted that the miscible oil ranging in strength from 1:10 to 1:20 gave the best results. The crude-petroleum kerosene and 10 per cent distillate-oil emulsions ranked second in effectiveness. Commercial lime-sulphur solution was found to be ineffective, as was whitewash. 104 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. SPRAYING EXPERIMENTS FOR THE DESTRUCTION OF THE EGG MASSES. EXPERIMENTS AT ESPANOLA, N. MEX. The work at Espanola, N. Mex., was conducted in the apple orchard of Mr. Henry L. Pollard. The orchard consisted of 14-year- old trees in fair condition. For the spraying a barrel outfit was used and the pressure maintained ranged from about 75 to 100 pounds. The number of trees in each of the plats is shown as follows: Plat I, 21; Plat II, 22; Plat TIT, 14; Phat TV, 22; Plat-V, 225) Plate yie The days upon which the sprays were applied were clear and quite cool. The results of the experiments are shown in the following table: TABLE IV.—Spraying experiments for destruction of egg masses of the fruit-tree leaf-roller, Espanola, N. Mex., 1911-12. J Total Percentage of egg num- Number masses— Plat per of | Pe of | “eregs | Of 2B6 Treatment. egg 88 masses No. count masses 5 trees. | MASSES | hatched Oe Un- : ob- ‘| hatched. | Hatched.| hatched. served. I | Commercial lime-sulphur solution at 1 gallon to 8 gallons water on December 14, 1911..........- 6 265 263 2 99. 24 0.76 II | Commercial lime-sulphur solution at 1 gallon to 10 gallons water on December i411 Ol ee eee eee 6 277 276 it 99. 63 or IiL | Miscible oil at 1 gallon to 15 gallons water on December 14, 1911..-.- 6 310 21 289 6.77 - 93. 23 IV | Commercial lime-sulphur solution = at 1 gallon to 9 gallons water on Hebrumanyiu pelo == ee ree aa 6 285 285 0 100. 00 0 V | Commercial lime-sulphur solution at 1 gallon to 7 gallons water on Hebrurany 07, 19222 2 ieee 6 252 251 1 99. 60 .40 VI | Miscible oil at 1 gallon to 12 gal- lons water on February 17, 1912. 6 272 16 256 5. 88, 94.12 Var WUnsprayed 745. 08s. ete: Bee ee 6 250 250 0 100. 00 0 As will be noted, the trees sprayed with miscible oil showed good results from the spraying. The spraying of Plat III with the oil at the rate of 1 gallon to 15 gallons of water prevented 93.23 per cent of the eggs from hatching, and Plat VI, upon which the oil was used at the rate of 1 gallon to 12 gallons of water, showed a benefit of 94.12 per cent in favor of, the spraying as compared with the checks. It should also be noted that all egg masses on the unsprayed trees hatched. The commercial lime-sulphur solutions gave little or no beneficial results for the treatment. On Plat IV practically all the eggs hatched, and on Plats I, II, and V there was only a benefit of 0.76, 0.37, and 0.40 per cent, respectively, from the treatment as compared with the check trees, upon which all the eggs hatched. THE FRUIT-TREE LEAF-ROLLER, 105 EXPERIMENTS AT CANON CITY, COLO. The work at Canon City, Colo., was conducted in the orchards of Mr. E. A. Davis and Dr. Allen Bell. In the Davis orchard 14-year- old Ben Davis trees were sprayed, and in the Bell orchard the varie- ties treated consisted of Ben Davis, Winesap, and Colorado Orange. The trees in the Bell orchard were sprayed with miscible oil at the strengths of 1 gallon to 12 gallons of water and 1 gallon to 15 gallons of water and with 20 per cent kerosene emulsion, but unfortunately the material was not at all thoroughly applied, and no conclusions as to the efficiency of the sprays can be drawn from the results obtained. Duties elsewhere required the absence of the writer from Canon City when the applications were made. The trees in the - Davis orchard, on the other hand, were thoroughly sprayed with a gasoline-power sprayer. The pressure maintained ranged from 150 to 175 pounds. At the time of the application the buds were just bursting and beginning to show the green. The results are shown in Table V. _Tasie V.—Spraying experiments for destruction of egg masses of the fruit-tree leaf-roller, Canon City, Colo., 1912. Number of egg | Percentage of egg | Total masses— masses— | Plat Count | number a | Treatment. tree of egg Pp No, masses 2 z Un- Un- observed.} Hatched. hatched. | Hatched.) 1 oichea. | I | Miscible oil at 1 gallon to 15 gal- 1 184 TAC) 5] |S See || ae lons of water on April 16, 1912. | 2 128 4 [2A yee ee eset we 22 / 3 116 a7 Zee 2.2 he ete. Ss } 4 135 6 AZO viele zoe Nees sie ae” 7 32 i) 176 8 LOS init. ariettes Ae td =o Bs 6 110 6 AOA en eck itel eae ft 4 849 33 816 3.88 96.12 II | Check, umsprayed.....-.-...... 1 155 155 Git [rad seceitals att a0 2 185 184 eee eee oe ees Se 3 178 178 Oi [sets tai bee eee ch re 518 517 1 99. 80 0. 20 It will be noted that a comparison as to the number of egg masses that failed to hatch between the trees on Plat I, sprayed with miscible oil at the rate of 1 gallon to 15 gallons of water, and Plat II, which was left untreated, shows a benefit of 95.92 per cent in favor of the spraying. : At Canon City, Colo., no experiments were performed with lime- sulphur. The writer had, however, an opportunity to examine sev- eral orchards in this section that were sprayed with this material against the Howard scale (Aspidiotus howardi Ckll.). The lime- sulphur was found to be entirely ineffective in destroying the eggs of the leaf-roLler. 106 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. SPRAYING EXPERIMENTS AGAINST THE LARV. The experiments against the larve were conducted in the Davis orchard at Canon City, Colo. This orchard consisted of many varie- ties, namely, Ben Davis, Missouri Pippin, Winesap, Paragon, Jeniton, Rome Beauty, Jonathan, Maiden Blush, Yellow Transparent, and Red Astrakhan. There were also a few trees of other varieties. The orchard as a whole had no more than a good one-fifth crop. On account of the light crop it was difficult to determine fairly the results of the spraying on some plats. In all cases the material was applied with a good gasoline-power outfit and a pressure ranging from 150 to 200 pounds was maintained. The plats contained trees as follows: I, ‘155; Tl,’'725 TH 3% FV, 6385 V, 46; Vil’ aay eae VIU 802° R941 5 X86! The results are shown in Table VI. TaBLeE VI.—Spraying experiments against the larve of the fruit-tree leaf-roller, Canon City, Colo., 1912. Percent- | Percent- | age of age of No. | . Treatment. injured | sound Condition of foliage. apples. | apples. Two applications of arsenate of lead, 3 pounds 20.00 80.00 | Good; no arsenical injury. to 50 gallons of water, May 2 and May 17 and 18. Two applications of arsenate of lead, 3 pounds 20.00 80. 00. Do. to 50 gallons of water, plus 4 ounces Paris green. n Sail III | Two applications of arsenate of lead, 3 pounds 15.00 85.00 | Very good; no arsenical in- lon to 50 gallons water, plus 40 per cent nicotine jury. solution (1:1,000), May 3 and 25. IV ; One application of arsenate of lead, 3 pounds 15. 00 85.00 Do. to 50 gallons water, plus 40 per cent nicotine solution (1:1,000), May 3. V | Two applications of arsenate of zinc, 1 pound 25. 00 75.00 | Fair; serious arsenical in- to 50 gallons water, May 11 and 25. jury. VI} One application of Paris green, 8 ounces to 50 18.00 82.00 | Good; slightly burned by gallons water, plus 2 pounds lime, May 4; arsenical. one application of Paris green, 1 pound to 50 gallons water, plus 2 pounds lime, May 18. VII | One application of 40 per cent nicotine solu- | No crop.| No crop.| Fairly good. tion at 1:800, plus 2 pounds of soap, May 11. VIII} One application of 40 per cent nicotine solu- 35. 00 65.00 | Fair. tion at 1:800, plus 2 pounds of soap, May 18. IX | One application of 40 per cent nicotine solu- 40. 00 60. 00 Do. tion at 1:1,000, plus 2 pounds of soap, May 18. XG | (Check *Unsprayedioc weve. - aoseaes sk eee ees 98. 00 2.00 | Trees nearly defoliated. Note.—Plats I, IV, VII, VII, and IX were sprayed with arsenate of lead at the rate of 3 pounds to 50 gallons of water for the codling moth when the petals had dropped. Plats II and VI received the same treatment for the leaf-roller as for the first codling-moth application. The damage to fruit was determined by making careful counts of fruits*from various trees in the different plats. The total number of fruits was not counted in any case, so the percentages given are only approximate. On Plat VII there was a total crop failure. As will be noted, the best results were obtained on Plats III and IV, where a combination of arsenate of lead (3:50) and 40 per cent nicotine solution was used. The 40 per cent nicotine solution was found to be effective only when the larvee were quite small. It was X THE FRUIT-TREE LEAF-ROLLER. 107 estimated that the tobacco mixture applied May 2 and 3 destroyed - about 50 per cent of the worms then on the trees. Plat II, which received two applications of the combination spray, showed no better results than on Plat IV, which received only arsenate of lead for the ~ second treatment. Plat VI (Paris green alone) showed a slight improvement over Plats I (arsenate of lead 3:50) and II (arsenate of lead 3:50 plus 4 ounces Paris green). Plat V, which was sprayed with arsenate of zinc at the rate of 1 pound to 50 gallons of water, gave disappointing results, as it not only failed to destroy the ae in goodly numbers but it seriously burned the foliage. The arsenical injury to the foliage could, however, have been prevented if lime had been added. An increased strength of this arsenical would no doubt have been more effective. On Plats VII, VIII, and IX, where 40 per cent nicotine solution alone was used, the benefit from spray- ing was considerably less. Plat VII of these plats gave the best results. On the day after the spraying, by carefully counting the number of dead larvz as compared with the living ones found on the trees, it was found that about 55 per cent of the larve were killed by the spray. On Plats VIII and IX not more than 25 per cent of the larve were killed. These plats, however, were sprayed a week later than Plat VII, and the difference in results was probably due to the fact that the worms at that time were more resistant to the tobacco mixture and that it was much more difficult to reach them in the rolled-up leaves. It will be noted in comparing the sprayed plats with the unsprayed plat as to the amount of injury to the fruit alone that there is much in favor of spraying. The benefit for each plat over the check plat is shown in percentages as follows: Plat I, 78; Plat II, 78; Plat III, 83;. Plat IV, 83; Plat V, 73; Plat VI, 80; Plat VII, 73; Plat VIII, 83; Plat IX, 83. The difference in condition of foliage must not be lost sight of in determining the benefit of spraying. The check trees were practically defoliated, while the sprayed trees retained their foliage throughout the season and were enabled to develop fruit buds for the following season. Although there is much in favor of spraying with arsenicals, alone or in combination with tobacco, they have not given entire satisfaction. LIGHT TRAPS. The writer had occasion to observe many lights used as traps to catch the moths of the leaf-roller at Canon City, Colo., during the season of 1912. The use of these traps was not advocated, but many orchardists were of the opinion that ‘a decided benefit would be derived if enough lights were placed in the orchard, as the moths were very readily attracted to them. Such orchards were examined 108 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. very carefully on several occasions to see if there was any appreciable difference in the number of eggs being deposited in them and in adja- cent orchards where lights were not employed. It must be stated emphatically that these traps caught vast numbers of the moths, but so far as could be determined there was little difference in the number of egg masses laid on the trees in these orchards than else- where in the same immediate region. Some growers, before the moths ceased flying, gave up the use of the light traps after they were convinced that there was little hope of receiving much benefit in that way. Light traps have never proven a success in controlling an injurious insect. Although some benefit may be derived, it is so shght that other means must be adopted in fighting the pest. Orchardists have told the writer of their endeavors to get rid of the leaf-roller by crushing all egg masses that could be found on the trees. Cases are known where growers have actually hired men to go over their trees during the winter for the purpose of destroying the eggs, thinking that it was possible to control the pest by such operations. In the spring they found, much to their surprise, that the steps taken during the winter season were of little use, as the — ‘‘worms” appeared, as usual, in enormous numbers on all trees. Under orchard conditions it should be distinctly understood that there is no hope of practically controlling the leaf-roller by destroy- ing the egg masses by hand, because the masses are deposited on all parts of the trees and their small size and close resemblance to the color of the bark make their discovery difficult. CONCLUSIONS. The fruit-tree leaf-roller in the larval stage has been found difficult of control because of the manner in which the larve feed on the foliage and fruit, and also on account of the fact that they are very resistant to poison sprays. Applications of arsenicals alone and in combina- nation with 40 per cent nicotine solution have greatly reduced the amount of injury to the fruit and foliage, but these sprays have not been so effective as is desirable. A series of experiments for the destruction of the egg masses, con- ducted during the dormant season, have shown the value of mineral oils. Kerosene emulsion, crude-petroleum emulsion, and miscible oils have been tested. The last mentioned, when used at the strength commonly employed against the San Jose scale—that is, 1 gallon to 15 gallons of water—will prevent most of the eggs from hatching. From 93.23 to 96.21 per cent of the egg masses were destroyed by this material on the experimental plats. Good results also were obtained by the use of kerosene and crude-petroleum emulsions, although these substances were, on the whole, not quite equal to the THE FRUIT-TREE LEAF-ROLLER. 109 miscible oils. The ease with which sprays may be prepared from these last commend them to many orchardists although the homemade emulsions are cheaper. In preparing a kerosene or crude-petroleum emulsion care is necessary to insure a thorough and stable emulsion. It should be stated that injury to trees treated with oils sometimes follows, although no such injury was noted in connection with the present experiments. No more spray should be used than is neces- sary properly to treat the tree, and the puddling of oil around the crown should be guarded against. _ Lime-sulphur solutions proved to be a decided failure as a destroyer of the egg masses. Strengths ranging from 1 gallon of lime-sulphur to 7 gallons of water to 1 gallon of lime-sulphur to 10 gallons of water were sprayed on apple trees and no benefit was derived from their use. RECOMMENDATIONS FOR CONTROL. Experumental work has shown that the best method for controlling the fruit-tree leaf-roller is by a very thorough application of a mis- cible oil at the rate of 1 gallon to 15 gallons of water during the dor- mant season. It must be understood that by thoroughness of appli- cation is meant the use of enough material to cover all parts of the tree, from the tip of the highest or smallest branch to the very base of the trunk. In order to do thorough work the trees must neces- sarily be sprayed from all directions. It is very often the case that the top branches or those around the inside are missed by the man operating therod. It must be remembered that only those egg masses actually hit or covered with the material will fail to hatch and those missed will surely hatch out ‘‘worms”’ in the spring to feed upon the trees. Orchardists should realize that thorough spraying with the right material and at the proper time pays well, but careless, haphazard work gives disappointing returns. All plants upon which eggs have been laid should be sprayed. Besides fruit trees, egg masses may be found on various shade trees, shrubs, and currant, gooseberry, raspberry, and rose bushes, ete. Eggs will also be found on buildings, spray outfits, wagons, fences, etc., and it istecommended that these egg masses be crushed so far as is practicable. The best time to spray is just before the buds burst in the spring. Late spring is preferable to early spring, as weather conditions are usually more favorable. There is also less likelihood of injury to the trees by the oil after the sap has begun to flow with considerable pressure. Spraying should not be done during threatening weather. Orchardists should bear in mind that the strength of miscible oil recommended is for a dormant spray and should never be applied to trees in foliage. -Spraying should be completed in the spring before 110 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. the buds have advanced so far as to have the green tips exposed. If the above precautions are carefully followed in applying the mis- cible oil, danger of injury to trees will be reduced to the minimum. There are a number of good commercial brands of miscible oil on the market. These miscible or soluble oils are so made that they mix readily with water. The material may be applied either by hand pump or gasoline-power sprayers. Power outfits are to be preferred. Nevertheless, whichever kind of outfit 1s employed, it is essential that it be provided with a good working agitator. To do effective work it is also necessary to have sufficiently long spray rods and leads of hose. Nozzles with medium-sized holes or apertures are recom- mended. Miscible oils at the strength recommended for the destruction of the eggs of the fruit-tree leaf-roller are valuable in controlling scale insects such as the San Jose scale (Aspidiotus perniciosus Comst.), Howard scale (Aspidiotus howard: Ckll.), ete. Orchards sprayed with the oil for the leaf-rollers will not require the usual application of lime-sulphur for the San Jose or Howard scales. In conjunction with the oil treatment in badly infested districts it is recommended that a very thorough application of arsenate of lead, at the rate of 3 pounds to 50 gallons of water, be applied when the larvee are emerging from the eggs. The larve will be found to be hatching just as the cluster buds on early-blooming varieties of apple are beginning to separate. The necessity for making this application will depend largely upon the thoroughness with which- the miscible oul was applied. Wei ease COPIES of this publication may be procured from the SUPERINTEND- ENT OF DOCUMENTS, Government Printing Office, Washington, D. C., at 10 cents per copy INDEX. Page. Agelaius pheniceus pheniceus, enemy of Archips argyrospila.....---.--------- 102 Emr ThaTiL Of ATCNiDS OQYTOSPUG.. -'5. ~~ 0's mms wcnjeiin ns aeien ee esceccceee 94 Ambrosia trifida, reported food plant of Polychrosis viteana.......-..-----+---+- 21 wamelocionus sp., parasite of Polychrosis viteana.........-.----+--00ceeeeeeeeee 48 Amorpha stems, reported food of Polychrosis viteana.......-..----++--++-+++-+- 20 Apanteles canarsix, parasite of Polychrosis viteana...........----+-+--+++--+-++- 47 DOTTIE y es aaa Se EEIEC OF POM CHTOSIS VULEOIG 5 anni: aa ann nn tenn cece nerd ome se 48 man lant OF Archips .argyrospild.....--....---- 22-22 eens nee e eee ne nee 92, 93 mae ood plant Of Arciii@e argyrospila...........----0.2--- een n-ne nee e eens 93 ne a acid Sens a wie ge sino inch we dian mee eee 91-110 TLS STE a 6 117 1 iS eae ae 96 Iie Distory and NADit8 56 on njeicvsinnestass ss. te s-- +> BOT conirol experiments, conclusions......-..-.-..+----s-.--s 108-109 CEUTEN CG) |S SOMATA Fn Aa a IPO Mewes 102-109 Ne eC PET OMAN OTIG oe oh rea ol ee ice anal nid sm 109-110 damage caused in Missouri.............-..--.- 92 Meret OM Ol SAPO. . s.06/. enone Sob og feo ee oe os Bee 96-97 SME ON Nk es a bo wih acs 93 RRM TICE O MOU yrs rc al ho oo aan Satta cian BS Ste whee Ve 96 en ae ISS. 2 Senin inyslt a ale ag 99-101 eggs, experiments for destruction..............-...--..--- 103-105 PORRINEES. tie hie ae R R s o hohe SO a Ste 102 RI LER eh ey ees rian Se hea sido aia SOS 93-94 Ue oan Se eM are ie eg ae LS ani oe 97-102 01 ESS Ar Na ag RES RSE RC ee 101-102 ei ea aia SR Mia red ren ee Ty is ot a 92-93 Re EAC UET oe an ara. n ncatee Son’n Menta kee HOUR NRE 94-95 in New York in 1911, Herrick’s description................. 91 CULO oo 0» 0. yee ws aim we ge a kim sn ee ne ee 96 aorecugeey are habits. on sci outs a An ata 97-98 MORIA Ie Nt aia 2 oa ie Dp CE Oe oe elie soe 97-102 PRR ck in Ri dally cist raat o Nate eas, cinta. 4 2 cael ee 101 BPO ES LO AOE WOSE «n= soit io gam waar bk maine owe oes 91 RR RAMU BS a Shas cee mn ohn di gbte Sih imme t= SEE 97 COTE LG a8 SMI I I IRS SS Se ae re 98-99 eemete O1lead against cherry fruit sawfly......-..1........00--ccdecncsececs 79 fall webworm as compared with lime-sulphur......... 84-88 SU EOE NOMI OT Cee iim nk oi a oni'en.d xb oe ea ae he ae 106-107 EB GION MOUs sin pada stn suas pens nin’ +s 9 cae kee bee 9-10 OT adie chi ie bn n oie 6 wk pcg Sad eh id ghd ade amie Dae nme oie tense ley > 73-79 adult, habits and seasonal history. ..............-....-+5 74-76 gg ee a a a ne a ae 79 114 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. Page Hoplocampa.cookei ege, seasonal history... .. sa) 52.4 Asse es Pe Se ane 76-77 CNEMIES i. 265 s.diee ans eee hee re ee 78-79 habits... 0)... Saks ee AO 74-78 larva, habits and seasonal history s2220>-2s. 459-22 eee 77-78 seasonal history ..... 2... is 2) Sse ee 74-78 Hopvines, food plant. of Archips argyrospilas 25.02 oo vos. eo A eee 94 Horse-chestnut, food plant of Archips argyrospila......-.....-- ao howe ear 92,93 HAyphaniria cunea, lime-sulphur as a stomach poison..-.-...........-.+-2200- . 81-83 Ichneumon parasite of Hoplocampa cooket......-...---.----- Le idee ee 78 - icterus spurius, enemy of Archips.drgyrospila..-.2< 2222-2 eee 102 Ironweed, reported food plant of Polychrosis wteana.....---..-+---.-++-+----- 20 Itoplectis conquistor, parasite of Archips argyrospila.........---5----52----ee 102 Polychrosis viteanac22 22 Be eee 48. Johnson, Fred, paper ‘‘Spraying Experiments against the Grape Leafhopper — in the. Lake Erie. Valley am POLL? wie kes Pe Gee a ee 1-13 Johnson, Fred, and Hammar, A. G., paper, ‘‘The Grape-Berry Moth (Polychro- sis vetedna Clem.)’! .fce cnn sadnedéc qo SeeOe Wa ee ee 15-71 Kerosene emulsion against fruit-tree leaf-roller eggs...........2.22.202--2000- 103 and lime-sulphur against codling moth. .............-...- 89 Kingbird. (See Tyrannus tyrannus.) Leafhopper, grape, control as affecting quality of fruit: .i2 sive See 10-12 results of spraying agaist ity. 2.10.2 bi 23 2. ee 12-13 spraying experiments against it in the Lake Erie Valley in. 1911; papericloe eum ae ee 1-13 treatment of nymphs with contact sprays..-......-..---. 1-2 use of combined contact and poison spray-..-.....-.----.- 9-10 vineyard experiments against itin 1911............2-... . 3-9 Leaf-roller, fruit-tree. (See Archips argyrospila.) - Eight traps. against fruit-tree leafi-roller::.....v2y..0 eset A ee eee 107-108 iiilac; food ‘plant of Archips:argyrospilaly Lo nee AUS a eee 94 Lime against fall webwormess...ec. Sobek. 22 ee ho ee 89 and Paris green against fruit-tree ieneralles SaAWee.. SORES eee 106-107 sulphur against Howard scale.-....-. sobbed. ee ee 105 and arsenate of lead against fall webworm............---.-- 83, 85-87 fish-oil soap against codling moth...........-..-.---- . ree 89 kerosene emulsion against codling moth............ 6 eae 89 as 4.stomach poison for ipsects;\paper-s. sss ue-). Leo. eee 81-90 commercial, against fruit-tree leaf-roller eggs. ..............- 103-105 Lobesia botrana, bibliographic reference. .........------------- eee ee eee aes 68 name wrongly applied to Polychrosis viteana..........-..-+-- 17-18 Locust, honey, food plant of Archips argyrospila.............--.- 2D, A 93 Magnolia leaves, reported food of Polychrosis viteana......-..-------+---- AEM 21 Maple, food plant of Archips argyrospila...-..-..-..----- DOE OS, Dee 92 soit; food -plant of Archips argyrospila 022020, HO 93 Margaroma quadristigmalis, host of Glypta vulgaris... .....+--..--2+---205--- 46 Meteorus archipsidis, parasite of Archips argyrospila........----+-2---+-+-+26- 102 sp:, parasite of Polychrosis viteana.0 2 IO. 2Se REPS POEL: 48 Microbracon dorsator, parasite of Polychrosis viteana......-..--.+---+--- 2220s 48 : mellitor, parasite of Polychrosis viteana.......-..-------- SPE 48 sp., parasite of -Hoplecampa eooheis: 2259 eS2 Fs OS PA 78 Mildew of grape, control by Bordeaux mixture... ........--.------2-22--25- 9-10 Nicotine solution and arsenate of lead against fruit-tree leaf-roller.........-.- 106-107 soap against fruit-tree leaf-roller...............--..-- 106-107 INDEX. 115 ¥ Page. - Nicotine sulphate and distillate-oil emulsion against cherry fruit sawfly....... 79 MITC EOTIUS TOLL. oo! oc. - s GE e an ee bile a ein Fee peel ee wl 48 Notoxus monodon, enemy of Archips argyrospila........---..-..5--.-+2++--0+-- 102 Peon aiiniro: Archips argyrospila. . 20... ede. leds cee ene ee. ee ee 93 ET IE Ol ATCRIDS ANGYTOS DUG. wcmie s Dende es 17, 18, 29 Petroleum, crude, emulsion, against fruit-tree leaf-roller eggs..............--. 103 Phoebe. (See Sayornis phebe.) Phylloxera lice and galls, reported food of Polychrosis viteana........-..----- 21 pommodecits Sp., parasite of Polychrosis viteana. .o2-..sj.40.22esse- esse eee eee- 48 Pimpla pedalis, parasite of Archips argyrospila............2.2----2--2200e ee 102 Planesticus migratorius, enemy of Archips argyrospila..........-.-------+----- 102 Plowing in the late fall and early spring against grape-berry moth............ 51 od, plant Ol-Archips arqyrospila.- 2.0.6.5. 2. ewes sce eee es ees deen 93 Polychrosis botrana, bibliographic references...........----..--2-----+--222-- 70 other species confused with Polychrosis viteana........-....------- 15 Rs S225 8 Lin) ih eae ie aetdheok - be, ginagher: teciued .naputs 15-71 SE CUPSCEIPHAONY ?. Sakti Ae a dry 9s Babe ween se B- 29 TABS EUnet Bin Au aks Oe Se ta ee i ee Abe oo Ots 22-23 IADR ys" aKsebeon 2 pad cceeit be ~tdasose » cesmciaee 67-71 Semmes TUNERS atts (vals Wetec oo a rh a a EERE Sais wikia as Seats 66-67 Gamer) Fecommendatonse « . ash }es osaeleose- ans Fee 62-66 Be tric Pe Ske 8 hk Rk as ae Eten” nied ao Sa Rae 28-29 Penpehivenioss OF LARVA. occiscahiaieess(- na ie DAasislaemeaaly 2 26 BROERT POMS, SO Cos Os yl herder fell bla. sais swam eke 18-20 Bee OSCR DONS. snr bik ciel owed aie 8s Jatasales donde ale 28 CUI GA DARARE NM Gee so i ibe cgin suis nie B-mu dtd. ook wetcead S 45-48 first brood eggs, period of incubation. ..................-- 32-33 larvee, feeding period, length.................. 33 Moths, QvipOM WORM dese» ing chosle-km ss Bhs sles} see 35-36 time of emergence....................-- 34-35 Dupes, Dib ermaAhons yh veo bs03-kahawsws sencwohs os 36-37 length, Gf bare iis claed.. 54 6 wyacste a a esl a 33-34 ERATIONS 17s id sec oie oh ase nanny tenia h< - devdene $b 32-38 POE RG oso i lc apt niastar wl Seach date bye Mba biai> w vksinen ts ne 20-21 116 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. Page Polychrosis viteana, habits and character ofinjury of larva.................:... 23-25 of adult or-moth’.2..20.0).2 222 see eee eee 22-23 history. 220s... 5.2 Sl Pe a 17-18 injury’of larva, characters: 2722.2. eee . 23-25 insects whose injury to grape berries is similar thereto...... 26-28 — larva, description sae o2 2 See eee eee oT See 28 destructiveness.../.....0° 20290. 2 eee 26 habits'2l.2. Less ler eee -- 23-25 injury, character woe ee eee 23-25 pt life cycle of first generation, length.......................- 37-38 history studies in 1909. )...5.3) 22.0. 2a 2. ee 30-41 summary! 280 NS eee 44-45 occurrence in destructive numbers. ..................---- 21-22 origin) tS, Taha ea ie 18-20 pupa, description’! 228 V2 2 ee ee 29 rearing records, miscellaneous, for 1907 and 1908........... 41-44 Femiedves Pte te eae ee i) 2 eee 50-67 seasonal history-.-5 22 225.2 2 A A ee eee 30-45 second brood eggs, incubation period..........-.......---- 38 larvee, date of leaving fruit. 2.2 |. 6/2. eee 39-41 feeding period, length..............-- 39 generation 002) /2 222 ae ee eee 38-41 similarity of injury to that of grape curculio (Craponius inz- GUAUS) 0% SOOO ES Se 16 spring brood of moths, length of life. .................-.-- eSB oviposition in confinement. ........ 31-32 time of emergence................-. 30-31 synonymy..2. 2.000.272 P oe 29 vineyard infestation in Erie County, Pa., degree........... 49-50 Poplar, Carolina, food plant of Archips argyrospila..................-- Ee 94 Prunus serotina, food plant of Hyphantria cunea....-.......2200- eee eee eee eee 81 Pyralid host of Glypia animosa_. 02 2222s PA ee eee 46 Quince, food plant of Archips argyrospilas: 2 25020.3 JA eae 93 Radish, food plant of Archips orgyrospilals. . 20 ee 94 Raspberry, food plant of Archips argyrospilar....0..2...... 522s eee ee eem ene es fruits, wild, food of Endospiza (?) viteana....--..-.-.------2006-- 18 wild, reported food of Polychrosis viteana......---.---+-+---++----- 20 Resin fish-oil soap, arsenite of lime, and Bordeaux mixture against grape-berry moth. 22025) 02 oc cote cee eae ee ee 54-57 Bordeaux mixture, and arsenate of lead against grape-berry Moth SRL es RR 54-59 Relinia argyrospila=Archips argyrospila® .! PO ee. ae See 92 otiginal Geseriptions 1.45.2. 2cen te Os ey eee ee ee 96 Rhubarb, food plant.of Archips argyrospila@. . |: 2. YO 292 22 Aha ee 94 Robin, western. (See Planesticus migratorius propinquus.) Kose, food plant of ‘Archips argyrospilat ee? - Se 7hk. BO. OOD ae, 2 es ee 92, 93 Roses, reported food of ‘Polychrosis witeanays: 222) 22S. oan ee vor ee be es eee 20 Sassatras, food: plant of Archips argyrospud jo) 2 222A oe os ee ee sae 93 ENG OSACAAM PUERTO, oo 5 st Se tajprlote Aare cna eee 18 leaves, reported food of Polychrosis viteana.......--------+---+++---- 20 Sayornis phebe, enemy of Archips argyrospila........-2--222-0eeeeeeeeeeete- 102 Scale, Howard. (See Aspidiotus howard.) San Jose. (See Aspidiotus perniciosus.) INDEX. | LET * Page ninric venomy Of ATchips GrQyTOSpula. . . 2.22. o nen wee wees cece eeeeees 102 Scott, E. W., and Siegler, E. H., paper, ‘‘Lime-Sulphur as a Stomach Poison ee ae ern eee ace be ae le dace meet mga dee tes 81-90 Siegler, E. H., and Scott E. W., paper, ‘“‘Lime-Sulphur as a Stomach Poison RI ek was hate dibidia/sye sae winis easle dt aeleceeeces 81-90 Snowball, food plant of Archips argyrospila............------+----+- ee Mane 94 Soap and nicotine solution against fruit-tree leaf-roller.............-.-.---- 106-107 fish-oil, Bordeaux mixture, and tobacco extract against grape-leaf hopper and other grape insects and fungous diseases..........---- He yr ee 9-10 Sparrow, English. (See Passer domesticus.) pamenurimenective against fall webworm.........-.-...-2-.------+----+---% 89 Sumac seed bunches, reported food of Polychrosis viteana.....-...---------+--- 21 Temperature in relation to time of leaving fruit of second-brood larvee of Poly- I on te ae ala gee gig Ged dies SE oe ages Geen s Baws 40-41 Thistle flower buds, reported food of Polychrosis viteana .........-.--.------- 20-21 Thoroughwort. (See Boneset.) mummerarugeriandana—Drocites obliteratus.....--....5---0.-+-+-2----2---40-6- 48 Paraswte OF POLChrOSts: WLEONG Lo so). we Scedaes bee ee Des 47 Tobacco extract, Bordeaux mixture, and arsenate of lead against grape leafhop- per and other grape insects and fungous diseases..........- 9-10 fish-oil soap, and Bordeaux mixture against grapeleaf hopper and other grape insects and fungous diseases.............. 9-10 emursetacainst erape leafhopper.-.-.-.2--.4-.-....22.- ete. lene dee ee 2-3 Ent OL GLY Pid ANUMNOSA... .. ~~... - =. oe eae ee ee eee nee eee 46 rund ——ATCh’ DS OTGYrOSPUd......-.-.-- ==. 22 see va deeeenencccseeees 92 ea —ATCHI GS ONGYTOS DUG. oo... ee ep Sep ge tee ene see ee 92 Trichogramma pretiosa, parasite of Polychrosis viteana..-..-.....--.++---+++--- 48 ° “Trimmings,’’ removal, against grape-berry moth..................-...----- 52 Tulip-tree leaves, reported food of Polychrosis viteana..............--+--+-+-- 20 Typhlocyba comes. (See Leafhopper, grape.) var. coloradensis (see also Leafhopper, grape.) Tyrannus tyrannus, enemy of Archips argyrospila......-.....-..--22-.0eeeeeee 102 nse — A DONTELES CONATSIY . «ee in ine he wwe we oe hoe ee ee ne 47 Vernonia. (See Ironweed.) Virginia creeper, food plant of Archips argyrospila.......- ie ee aoe SE SSSA ice 94 Seamate lack, jood plant of Archips argyrospila.* ......-.--.. 22-2 e ee seeees 92, 93 Webworm, fall. (See Hyphantria cunea.) ' rane plant Of Archips argyrospila. .-....-...-- 22.222 ce eee ween te neces 94 Whitewash against fruit-tree leaf-roller eggs..............--..---- 222 e eee eee 103 ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D, C. AT 5 CENTS PER COPY Vv a. ; so 2 ve Co oS ERAS ie uN MELO, By PS re « ’ 5 r* “Sa as f ; bs Bale € mig} Ay ao ’ » , J + v2 int ~ ‘ 4, - ae % a ms co se bes sy Sate 2 CA ee Ak) “Pipes Ts Lr ay oe $ £%3 4 . wie La, me ‘ RoE Vet es st > i = ‘ ie ao Gun” ’ ort eas i me is Se dec aa ope ce ae, tae ghee Nay at ait rere ae ihe ry. hae ote SN ce ke UES wall suit ' ee Fp! ur Se oat 2h ! y y 4 ee =f per er % * ie a bat Fah fei) ch igs o baiy, Bakganett eS The york DOR OH AE eE aiceadins’ 1 ios abet hy eet bog SG Bears Dalene coma a 27 eee : ore! its he ES ie Ay P 4 oe , oe ee “ PSR! e i rhe y. % ie i ee Ts 4 . Ny 5 oe | Pra wr Ch eae ee ‘fe “ 7 _ ' - e Be’ al ; f e 5% ab aed d ey abot Netee hi a ibe § ead fae ) 4 orale Pe ew aang a . Ab tae OS gy als alte ie ata ious ie crea ; ty 2 Seem eeu a tar Or me ybespsinwet vs y fs eens # i hy ‘ eB if ie Br ? 3 “ t : hehe 2 < tig aie : ae, cs x i ( ‘ ‘ Beek Be Whe WEAR ety 0, eee = 4 “e 4 « ‘ od ba 5 , Z > = 0 +, - oY a! bh. ts Ree - s ' t. 7, ? Lor SPIT fey Ss aay 7. y Deeb i map erat imately. Sar Yo Ae Sie ag pe re Came, statin fe Beas bere Poe, Cir Lee St shack cade Soy 2 ae yabr ORS, Lia ae. ode), ce OAT AP RES, ee Pa dete Pia Be prises eat cate ape nol oes. a © / ; i A, : < é ee am 4 Ms Ba ra “4 qieeta a elie hy eae : ieee inpodetpt x cay eee Br a ~t eet x, o/c Saeaesscsem aaa Sate AT wets LL tea ; ur Dish a CoAT gees CRA’ oe ac pee a eae. Te. Bae eeu _ anceenoaiit : “ye grace ea iE Mental aoe Limb? . . 1 a a8 ag \ a ‘ A L} - s . i Y B - ; _ 2 ‘ j P PE rae A } Soe oe eatin 4 7 i = * we gs . eas . 4 d f 2 iby i .: CF Toh RE ae fate ae ener wit SSC mE IAN Mie ES : Ms eee eae ae eT os } Wie Cae ee ey RRL ey eve anny Ke DEPARTMENT OF AGRICULTURE, - BUREAU OF ENTOMOLOGY—BULLETIN No. 117, 0 Pern G: HOWARD, Enarticlogst and Chief of Buicau, fee RUD SPIDER.ON HOPS =|] IN THE SACRAMENTO VALLEY OF CALIFORNIA. | WILLIAM B. PARKER, M.S., Lo ere i ‘ Entomological Assistant. fb eiis ‘ pe 5 4 4 ; ‘ : > x V2; ry ¥ IssureD May 3, 1918, te as , Ar ; 6 Pyiei ye. al Ne ‘i: \ for we rs are | ‘ 7 . z r han’, Gkls } ; ( A ls ) %y ‘ c “ ) 4a ‘ \ “ t k > ’ J) b Te i 4 ‘ oa 4 : _> f hs a) f - e . : = WASHINGTON: rep N GOVERNMENT PRINTING OFFICE. . RA: 1913, | Ea ka a ees o oe ee i pee a” ae ) iP 4 i > we sn te ‘ 7 U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN No. 117. L. O. HOWARD, Entomologist and Chief of Bureau. THE RED SPIDER ON. HOPS IN THE SACRAMENTO VALLEY OF CALIFORNIA. BY WILLIAM B. PARKER, M.S., Entomological Assistant. IssurepD May 3, 1913. X LO Ro SORT cellist I. tan ies milo { conn | i Ni el nial Pee nell fh ne a : SS ESS 555 ED S wy WASHINGTON: GOVERNMENT PRINTING OFFICE. 1913. BUREAU OF ENTOMOLOGY. L. O. Howarp, Entomologist and Chief of Bureau. C. L. Maruarr, Entomologist and Acting Chief in Absence of Chief. R. 8S. Currton, Executive Assistant. W.F. Taster, Chief Clerk. F. H. CuitrenvDEN, in charge of truck crop and stored product insect investigations. A. D. Horxtins, in charge of forest insect investigations. , W. D. Hunter, in charge of southern field crop insect investigations. FE. M. WEBSTER, 17 charge of cereal and forage insect investigations. A. lL. QuAINTANCE, in charge of deciduous fruit insect investigations. E. F. Paruirs, in charge of bee culture. D. M. Roasrs, in charge of preventing spread of moths, field work. Rouia P. Currie, in charge of editorial work. MaBEL CoLcorD, in charge of library. Truck CrRoP AND STORED PrRopuct INSEcT INVESTIGATIONS. F. H. CuitrENDEN, 7m charge. C. H. Popenor, Wm. B. Parker, H. O. Marsu, M. M. Hien, Jonn E. Grar, Fred A. Jonnston, C. F. Srann, D. E. Finx, A. B. Duckett, entomological assistante. ° I. J. Conpit, R. 8. Varze, collaborators in Califorma. W.N. Or», collaborator in Oregon. Tuos. H. Jonss, collaborator in Porto Rico. Marion T. Van Horn, Pautine M. Jounson, Anita M. BALLINGER, CECILIA SISco, preparators. y) LETTER OF TRANSMITTAL. U.S. DEPARTMENT OF AGRICULTURE, BuREAU OF ENTOMOLOGY, Washington, D. C., November 15, 1912. Sir: I have the honor to transmit herewith, and to recommend for publication as Bulletin No. 117 of the Bureau of Entomology, a manuscript entitled ‘‘The Red Spider on Hops in the Sacramento Valley of California,’ by William B. Parker, an entomological assistant in this bureau. . This manuscript deals with a pest the study of which has been hitherto largely neglected and which of recent years has attracted much attention from an economic standpoint, on account of immense _ losses to growers of hops and other crops in the Pacific coast region and elsewhere. Mr. Parker’s studies, as outlined in this paper, have added con- siderably to the knowledge of the habits of this pest and have shown methods by which it may be economically controlled. Respectfully, L. O. Howarp, Entomologist and Chief of Bureau. Hon. JAMES WILSon, , Secretary of Agriculture. ra eT % CONTENTS: En soe mn dm pen neces meee ang erences I ee eee ede cam eh new ke dhevts leedeee I eo ah ec bad nae e age cence eden ae los parley EINE. 0 8c.06. be. ss cs eh ewe er IP late alah Ee ei ra aed ee A ee es et a Meemeon pinged. ...-.-'). 02... .0.-26-- 2. bepat, C Pe were, oo em eer EEN ees he ok SN ws She Leg do bes MIs 2 TSN 8 2 Sd. at) en ee cen ome PS ee oe IE rs ee Cae oS oS os wic'ins Sem ges ep voles Beas aE ese me sense Slee ive PY AG ee se eee 6 IIE 85.2602 Scot Jb Poks s Soe Se lens ood pease ote Se ieee Bp ate gee SE Ped U Ne Ie etery 8's ri hh os de ak deb tt oot 2. Pee ie Se - ee ee oe ae oe elec bee Seenreinom Nibermation._.... .. 4... -- 25. -- +. sete ee ee Se ee A ee Meeermesranice Of mites on hops.......-./--.--... 2.2 -.3....2..2.4. ts aie ic is tet oa dee be eee General effect of mites upon foliage... eh fk A eR SE Ie Se ees eet ae Relative effect of mites upon male and female hopvines...............--- mena tne duality of the hops.............25..0..-..--+.22----sb--- ER LS a a an oe ec utc he Mae asa eed we ao oe Distribution in the field.............--.. Ath 2 Sess Gre MN Oe eM ae pee hh III cee ee Ts Le ke wink d= aera Gs BOM Se he eine Experiments for the control of the red spider............---.-.----- fc hoe EI MEETIMGONCAION ..~ -.- 2 2--- 2... eb cw ee cin ee ce eB ene eeeee Ese, et he SE cs kat ale Ste Seid ae sk Gowen IE 5 te Bn rr Na Re aL aa alg hea Ws wh gata OA EET ID ep CO Pe ene ge a EERE iy 0 SE LOOT ore gaa ie wo Binoy e ek acm cio gk ae ese 3 ac oad DS Sle pld Seg'wm Gin 'm we ee wa hn ee ss aes ER re Nat th So wk gh od Kis nine = en ol 3 08 Sim Se > we wil es maewame solutions and other materials. ...........5....2 2.2. e cee ee sees A RSP Te SEE MGS Eg 8, EEE MOTICRINONL ais ok care x wieniaploia se panes Ave dens Shing he ae dda ee ER a ee ken dai pe NE wie dy Wik a2 alTs ad Bix cde oak ok anos REN Sac dada ge a doe ein did ween Swe Gs we ane oe eae cee NIL et GS aca 2 Pe nih eS eia be Kee wy Ls a oak 9 cid n'e nip wie eat ae III UUTIID BOVOVE. 7 “ 4 5 ' ' n . : = on ' 4 EXPERIMENTS FOR CONTROL. 25 however, an effective, convenient, and nonoffensive spray, and the cheapest one that has been successfully used against the red spider. LYE-SULPHUR. The lye-sulphur solution (Formula No. 1), used with success against the red spider on the almond by Mr. W. H. Volck, was applied with flour paste and with cresol soap in various proportions. The results of these experiments (Table VI) were obtained from tag counts and are very promising. The lye-sulphur solution, used with either the cresol soap or the flour paste, was very effective, and when used in the proper propor- tions did not injure the foliage in the least. It would have been used more extensively in field experiments had not the lye been disagreeable to handlé in making up the stock solution. The lime- sulphur on the market at a relatively low figure proved just as effective as the lye-sulphur and, bemg much more convenient, was preferred. TABLE VI.—S praying experiments with lye-sulphur in various combinations against the red spider on hops. ke Dae: a Per ,|Cost per s Applica- er 0 er of | cent o F No.| Date. Material. ent mites’ | mites’| mites | 200 | Mdlect om wine. present.| killed. | killed. gallons. 1 | June 23 5a a 4-100; cresol | Thorough. 377 367 97.4 | $1.05 | Slight injury. soap, 1-300. 2| June 26 | Lye-sulphur, 2-100; sul- |...do...... 374 366 97.8 .708 | No injury. phur, 15 pounds to 100 gallons; flour paste, 4-100. 3} July 2) Lye-sulphur, 1-100; sul-|...do...... 371 361 97.4 55 Do. phur, 15 pounds to 100 gallons; flour paste, 4-100. 4/ July 15 | Lye-sulphur, 1-100........ SOs ene 518 458 88. Se00ue.| Lye-sulphur, 2-100. ..:.-.-- Lseovopee eae 437 384 87. 515s Do. Do. CO Or io) — Although the lime-sulphur, or lye-sulphur, and flour-paste solution did not injure the foliage or the blossoms of the hopvines, it did injure the more tender hop cones. The late spraying with lime- sulphur, if practiced, should be completed before the hop cones come out from the burr. NICOTINE SOLUTIONS AND OTHER MATERIALS. The nicotine solutions, used with the lime-sulphur, or with soap, or alone, were quite expensive, as may be seen in Table VII. The lime-sulphur and flour paste was so much cheaper and so effective that the nicotine experiments which had been outlined were conducted onasmallscale only. The results of these experiments, together with the results of some miscellaneous experiments, are given in Table VII. 26 THE RED SPIDER ON HOPS IN CALIFORNIA. TaBLEe VII.—Spraying experiments with various combinations against the red spider on hops. Num- | Num-| Per we ber of | cent mites | mites jof mites present.| killed. | killed. | ®#!ons. ) Cost per No.| ‘Date. Material. Application. “ 1 | July 15 | Nicotine sulphate, 40 per cent, 1-750..| Thorough, but 450 263 58.4 | $1.66 beaded. 2 |...do.....| Nicotine sulphate, 40 per cent, 1-1,000.}..... (0 es ee reed 414 376 |) 90.8} ~ 1.25 3 |...do.....| Nicotine sulphate, 40 per cent, 1-2,000.|..... SO. le = oe ih 0 762 677 98.9 . 62 4 |...do.....| Nicotinesulphate, 40 per cent, 1-3,000.|..... dongs = eee 414 263 |. 63.6 . 416 5 | July 16 | Nicotine sulphate, 40 per cent, 1-60....).....do..........- 237 185 78.1 1.08 6 |...do.....]| Nicotine sulphate, 40 per cent, 1-|..... GONG scec ete 312 273 87.5 . 85 2,000; lime-sulphur, 1-86. 7 |.-.do.....] Nicotine sulphate, 40 per cent, 1-|..... dO. feat 361 280 78.6 . 64° 3,000; lime-sulphur, 1-86. 8 |...do.....| Nicotine sulphate, 40 per cent, 1-750; | Thorough, not 330 225 68.3 2.08 cresol soap, 1-300. beaded. 9 !...do.....| Nicotine sulphate, 40 per cent, 1-'!..... Gorsassauens 164 111 67.7 1. 67 1,000; cresol soap, 1-300. 10 | July 17 | Nicotine sulphate, 40 per cent, 1-|..... AGss 365. sas 269 174 64.7 1.04 2,000; cresol soap, 1-300. 11 |...do.....| Nicotine sulphate, 40 per cent, 1- |..... GO: 2-S8\.- EEE 201 115 57.2 . 83 3,000; cresol soap, 1-300. 12 |...do....-| Lime-sulphur and nicotine sulphate, | Thorough, but 273 191 70.» leeesoets 1-50. beaded. 13 |...do.....| Lime-sulphur and 40 per centnicotine| Thorough, not 163 157 9658s 5 Cass L sulphate, 1-50; flour paste, 4-100. beaded. las |code. 2a EP lourpaste; 4 -100rs. oes sete ern dO caer ae. 657 444 67.5 . 09 PURE WATER. Spraying with water is one of the most successful and most com- monly used methods of controlling the red spider in greenhouses. With a strong but fine stream of water the mites are washed from the foliage of infested plants and the infestation is reduced to a minimum. It was thought possible to wash the mites from the hop leaves by spraying water through a coarse nozzle at 200 pounds pressure with about as successful results. This experiment was accordingly carried out, and although some of the mites were washed off, many were left and were later seen to have been uninjured by the force of the spray. The lime-sulphur-and-flour paste and the flour paste, 8-100, are so cheap that even though between 50 and 70 per cent of the mites could be killed by pure water, one of the former materials, which destroys about 98 per cent, is preferred. VALUE OF A SECOND APPLICATION. After a few spraying experiments had been conducted it was seen that the sulphur, the lime-sulphur, and the lye-sulphur had no effect upon the mites except by actual contact; therefore the idea of placing a material on the vines which would kill the larve on emergence was abandoned. Although nearly 100 per cent of the mites living upon the leaves could be destroyed by the spray, the eggs were uninjured and the newly hatched larve reinfested the leaves as badly as before. It was therefore decided to spray a second time after all the eggs had hatched and yet early enough to prevent any larve from becoming mature. EXPERIMENTS FOR CONTROL. 27 During July the mites passed from larva to adult in 8 days and during April the incubation period was 7 to 10 days.’ Basing the time of a second application on this data, 7 days was decided upon as the interim between the first and second sprayings, and by follow- ing out this plan some very encouraging results were obtained, as shown in Table VIII. TasLE VII1.—Experiments showing value of a second application in spraying for the red spider on hops. Num- Second Num- | Per . ) Vaber‘of appli- No.| Date. Material. Appice mites cn ania of | cation, Pres- | iilled, | killed, [Per cent ent. killed. 1| July 6 | Lime-sulphur,36° Baumé, 1-86; flour paste, | Thorough. 593 543 90 97.1 4-100. 2 | July 19 | Lime-sulphur, 33° Baumé, 1-70; flour paste, |... -- (Ons 143 142 99.7 99.7 Cee Lime-sulphur, 33° Baumé, 1-70; flour paste, |... .-. Gomes-2 509 440 86. 4 92.9 4-100. It will be noted that only from 0.3 to 7.1 per cent of the original number of mites present on the vines were present after the second application. The mites which hatched from the few eggs that remained were not sufficient to form the basis for a reinfestation and the work was accordingly considered satisfactory. Unfortunately some of the plats treated were covered with infested morning-glory vines, which were severely injured by the mites, and which later resulted in a migration that soon reinfested the hop- vines. Morning-glory was not present in one plat, however, and although the applications were made so late that the vines were severely injured, the results to be expected from such a plan were clearly proved. These vines were comparatively free from mites at the end of the season and had a much more healthy color than the vines in the adjoining plats which were used as checks. FORMULAS FOR SPRAYS. To prepare the flour paste, mix a cheap grade of wheat flour with cold water, making a thin batter without lumps; or wash the flour through a wire screen with a stream of cold water. Dilute until there is 1 pound of flour in each gallon of mixture. Cook until a paste is formed, stirring constantly to prevent caking or burning. Add suffi- cient watec to make up for evaporation. (See Pl. VI, fig. 1.) For spraying with flour paste alone, use 8 gallons of paste as pre- pared above to each 100 gallons of water. For the flour-paste and lime-sulphur spray, use 4 gallons of paste to each 100 gallons of spray containing the lime-sulphur. 1 In moderate weather ellaw 10 and in hod weather 7 7 day s between applications, 28 THE RED SPIDER ON HOPS IN CALIFORNIA. BANDING WITH TANGLEFOOT. Banding with tanglefoot has become the chief method of control- ling the hop flea-beetle (Psylliodes punctulata Melsh.) in British Columbia, and as the mites also work up the vine mainly by crawling it was deemed advisable to attempt to check their progress by means of the tanglefoot bands. In order to test this method, 10 infested hopvines were selected. . 22 22. 4. 2242925500555 eee 34 upon plants other than hops and cotton................. . 34-35 cost of spraying hopyards. 52.5 boo 52. mabe t= ee oe 30 cultural methods onghopss 2 gin. en2ee > secre ie se tee ee 30-34 damage to hops, nature..........- itis Re 2 Wierik he oe 17-18 distribution im: the field.) 3.21927 22k se ee ae 18-19 economic importance on hops. .-....-..--- Uacyic: Dev eh aera aa 9-10 effect Upon: Mans... Soy heel belly ape 18 ego, description, location, incubation 3222-2 — 2 22-92 2e2= po eee 10 emergence from hibemationg =)... .05)5.-\ 2a ON ee ee 15 enémies, predaceotis:... 522 Rows ano he eee ee ee ee 19 first appearance on hops injseason..9) 022 22. pe toe 15 food plants... 0. 2/535. ate es bE oe ae ee 16 habitation: om hopse- 20h si ae eh ee ee oe el 13 facia SS Ou ats Se ed ge ee ee Pires aman tees canter WOT S - 13-16 inibertiaiion. - Ys) 2 Re oe ees eee 13 emergence thereirom: S425 33... 2b Be aoe ~ ‘Caio oe 15 larva, descriptive, length: of stages. 2c. oo see ee ae ae es hife distory om hops ce ea Ln 2 27k ieee eee ee 10-12 Locomotion’. 2, cics Os ee hs aes ene oo oe ee 14-15 methods of applying Sprays onthops. .. 22.228 aaah ee ee 29 MIiOTALING ACtIVILLEDA. ©: 10. her ee eh ee oe eS ee ee 15-16 nymph, descriptive, length of stages: - 57.52. cole ea 7 eee 11 protection’on hops... 2 yei Ao eee Si Oe ee eee eee 13 summary, with recommendations for control......-....--.------- 34 Rose, ied plant.of Tetranyeiis. DEmocw lars: me So ees Lee Poe ea Le tans 16 Roses, greenhouse, protection from red-spider injury. .....------------------ 35 protection, from red-spideramjury: 3.0) 62 eee oe ene eee 35 Rudbeckia sp., food plant of Tetranychus bimaculatus.....--.--.-------------- 16 Salvia, food plant of Tetranychus bimaculatus.. 2.0 1.20 oe te ee ee 16— Sassafras, ornamental, food plant of Tetranychus bimaculatus.......----------- 16 INDEX. 4l Page menroinrips sexmaciulatus, enemy of red spider.:........-.2....--.2.---.acs.--- 19 Scymnus marginicollis, enemy of red spider...----....-.-.----------2---eeee- 19 maeeomencrmyeO! Ted. Splders: 240. 2k ise coe Pe ee ee ee ee 19 punctum. (See Stethorus punctum.) Sechium edule, food plant of Tetranychus bimaculatus.....-....--.------------ 16 Sisymbrium officinale, food plant of Tetranychus bimaculatus..........--------- 16 Slipper flower. (See Calceolaria sp.) Smilax, Boston, food plant of Tetranychus bimaculatus...........-+--------+-- 16 Soap, cresol, and lye-sulphur against red spider on hops........---.....------. 25 nicotine sulphate against red spider on hops....---.---....- 26 Solanum muricatum, food plant of Tetranychus bimaculatus........-..---.----- 16 Spider, red. (See Red spider.) Spraying apparatus and methods against red spider on hops. ..-.-..-- eM as 29 Reaeaeatns, ned spider on hops... ...--.:---2-/-0-'.2----. he 30 Spruce, Colorado blue, food plant of Tetranychus bimaculatus.............---- 16 emene, ced plant ot Tetranychus bumaculatus..-......-- 22-22-2222 ec eee ee et 16 feareemonrem:red-spider Injury... .2--...-.-.-+--.4..-2--. evel eles 35 Pare nunc, enemy of red spider.-.-.../..-.-----02-------62--220 pee .19 Sunflower, food plant of Tetranychus bimaculatus.........-...-----:2--------- 16 wild. (See Helianthus lenticularis. ) Pemmmmanaitietn red-epider on beat... ... 0.222222. .222 22. eal e ee lee eee le. 35 aes ope a, Pee ek AS ae 20-22 reisan jor ineflieleney!.}.. 200002 22h 22 planta Other than WG Ps. wo2. ..- e o ee lel 22 PaeebUIgy Koti ee Ck Oe Ee wes ae as 35 SD [UCTS SUL ASG. ala gg 8 CRA ee 35 powdered, against red spider on sweet peas..........---------------- 35 Sweet peas, protection from red-spider injury..............--.-..-.----------- 35 @amereroot bands against hop flea-beetle....-....-..--.-...---.------+242---- 28 Poe PICer Olb WOT Reta. o2e nica! bP ye Sey ee 28-29 Tetranychus bimaculatus. (See Red spider.) eri NETINUCKUS DVMACUINGUS. 04 222) 22 ee eee Ble ee kt 35 emer s, errs, LOCAMOM sty.) on seck ss eae bata -- cea Seen ae 10 telarius, name wrongly used for Tetranychus bimaculatus........-.- 35 Thistle, blessed. (See Cnicus benedictus.) Thrips secmaculata. (See Scolothrips sexmaculatus.) Thunbergia, food plant of Tetranychus bimaculatus...........---------------- 16 namaste tooa plant of Tetranychus bimaculatus..............-.2-26 2-20-22 200e- 16 Puuenrenainaniosius, enemy of red spider...............-22-- sees - cece e eee enee 19 menor, ememy Of red spider..23-... 0... 2 2. 2.22. ee ee ane 19 Tropxolum peregrinum, food plant of Tetranychus bimaculatus............----- 16 Verbena, food plant of Tetranychus bimaculatus..-.........--..2--.-2---200-- 16 Mamet. tood plant of Teiranychus bimaculatus............ 2.202200 cee eel eects 16 eer eruatineg place Gi red spider: ........ 1 /. 20-2... pees tween acc eee i. reo LIOl (00) TOO-BMIGr INJULY.. 2.2 ae eek ele ee ee ends 35 Watermelon, food plant of Tetranychus bimaculatus..............------------- 16 meiiray. opainst Ted spider On hops......2........-.-2.0c ce deececcenccees 26 Wedding bells. (See Burgmansia arborea. ) Wistaria, food plant of Tetranychus bimaculatus................------0e+ee2ee 16 O ‘ Hg RA” a = OF ENTO 08 wy | Ss if bg yt Ms Te Ww ard_ my ‘ Mek. a ’ a4 eae itis wr cp. Oo —e cone in ¥. f Ho Dw f & 7 4 1s, ya San . X . s ‘ ce td } rhe, Mg . ae ine ¥ my tan Q a 4 ’ : “al See ¢ Oe yt R Gh : s ee te a a ao T 4 3 — 4 pe ; 3 Laser © amy N ‘N vi | iQ a ; Nod j ie) Cy Wg = ; ; rR) Wank . a - ! _ Jeo ede! * Kg eS. . AK png. Se ** fe) ee, we 1 : SS ay } ie NTT 48 j y hw oy Pee £0 “Pf a i x OE te t Y , Nz ‘ n y s ; * . ; hg il “a t Arh 4 “ : t \ irc 7 va "i : Te f = 1 ry A . ; r ; SEM Bteabr aes 5 2. eee Entomological Assistant. , x - } - ad's od - ay

he | WASHINGTON; © ie “Ne GOVERNMENT PRINTING OFFICE. | . xy hn Te . re ae > be #3 \ 1912, ‘ f : " . be feo DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN No. 118. L. O. HOWARD, Entomologist and Chief cf Bureau. THE BEAN THRIPS. BY H. M. RUSSELL, Entomological Assistant. IssuED OcrosEer 16, 1912. _— SS —_ VEN = Sa == HE AD " Nuon ue! OU wily AN d WASHINGTON: GOVERNMENT PRINTING OFFIOE. 1912, BUREAU OF ENTOMOLOGY. L. O. Howarp, Entomologist and Chief of Bureau. C. L. Margiatt, Hntomologist and Acting Chief in Absence of Chief. R. S. Ciirton, Hxecutive Assistant. W. F. Tastet, Chief Clerk. I’, H. CHITTENDEN, in charge of truck crop and stored product insect investigations. A. D. HopPxKINs, in charge of forest insect investigations. W. D. Hunter, in charge of southern field crop insect investigations. FY’. M. WEBSTER, in charge of cereal and forage insect investigations. A. L, QUAINTANCE, in charge of deciduous fruit insect investigations. HK. F. PHILuips, in charge of bee culture. D. M. RoceErs, in charge of preventing spread of moths, field work. RoLtta P. Currig, in charge of editorial work. MABEL CoLcorD, in charge of library. TRUCK CROP AND STORED PRODUCT INSECT INVESTIGATIONS, I’. H. CHITTENDEN, in charge. H. M. Russeitit, C. H. PoPENor, WM. B. Parker, H. O. Marsi, M. H. Hien, Frep A. JOHNSTON, JOHN E. Grar, entomological assistants. I. J. Conpit, collaborator in California. W. N. Orv, collaborator in Oregon. THomAsS H. Jonss, collaborator in Porto Rico. Marion T. VAN Horn, PAULINE M. JOHNSTON, ANITA M. BALLINGER, prepardators. 2 DDITIONAL COPIES of this publication may be procured from the SUPERINTEND- ENT OF DOCUMENTS, Government Printing Office, Washington, D. C., at 10 cents per copy LETTER OF TRANSMITTAL. U. S. DeparTMENT or AGRICULTURE, Bureau or ENToMOLoeGy, Washington, D. C., April 24, 1912. Sir: I have the honor to transmit herewith for publication a manu- script entitled “'The Bean Thrips,” by H. M. Russell, an entomo- logical assistant of this bureau. This bulletin deals with an insect pest of the family Thripide, the study of which has been hitherto largely neglected, and which of recent years has attracted considerable attention from an economic standpoint, as the cause of immense losses in the Pacific coast regions . and elsewhere to truck farmers. The insect is closely related to the tobacco thrips, as well as to the onion thrips, to which species are chargeable untold losses in the production of these two staples. Ex- periments to produce formule and devices with which successfully to combat this insect are being perfected, and methods for the com- plete control of the pest are early expected. I recommend the publication of this manuscript as Bulletin No. 118 of this bureau. ’ Respectfully, L. O. Howarp, Chief of Bureau. Hon. James W11son, Secretary of Agriculture. CONTENTS: I to oe oP So. OY raves eee kee e eet lee Ss, PINE MEICHL OF UNiULY. 2... ..-.-. 2. - 2-2. ee ee eee eee ee eee ee fs ko ane de ene en ek pede ee Sete Hewes III Ore ns en Ou) ey eh eet ae ITER EE hE So, Ve cas ad a OG A SP MeRO CONAN 2: Lf 22 l 2 et oe ee ne eee eee eee III Se see ret ai d= ye OE Be eee ee pee EMEC ETN eo SP: Sos wept eee oe bones Sate ee ee Seperrmemisme arya 2 2. be ee ree ee ee A es PP Mp OF PLepupa..- =. =. 22. 5.- 2420-2 eee ee ee Se eee ee Pe AMmGm yp OF pupal... 2-2. -.-:-..52---22----- +2 - eee ee ee EI TIC toi) ih a a ns a oe weed 2 ee eee ee a ES en a sg SSIES ES ES gg ee pe I TS pe ee ee te oe ae he a een Se 32 Sele oe ETT 5 ae I oe a Method and time of oviposition. ............-- Number of eggs and period of oviposition... . . Pronermen Of the sexes...........-..------.- EmCLUOUS =. os." wk). 252 RE eke Slee Re ee kn Ee ee eine en ER ee 3 Pe ea ee ka we TE Fe 22s hee Qo I) eS oc so die ew pe MOR Scie ys eet eee cae Wate iw Te ese Oe IMGT etl 2 oe by oes x ha eae ee wah oots Coe eee lke Meeamioruse In Wwinter..............-.----- SIEISTY He See eS a ne ee a Habits of the prepupa and pupa. ................. ge ee as a ib 0 eeu icoaiui nlawinrn o'ete bins We we Seasonal history at Compton, Cal................. IME ge Sie ya we sa dig ek Kv eww pew 6 oie IE Pe Op cee ee ee BEE DTODUDA ANG DUNS. 0.5... eck cee ewes ECS Os ae se Ab wa ne obs ehis.¥ Penis Emergence from hibernation...............-.. mmerance into hibernation. .... ..s0cs--. esses. Wumiber of generations... 2... ..cs-seccrnceces ee a re ie eee Se ee oe ee a a oO a or ae ee Stich Tee Deep eeu s €S € oye Bie SS 8 os A es ee ee ee a a a a es 5 6 THE BEAN THRIPS. Page Seasonal history inthe Impenal Valley.-.2..2--4c. . Sa ee ee SL Ege permod? 2... 222525225 6 eS 37 Larval period... i2.s0.0..4. 02555. suber 38 Prepupal-and pupal pentods.:. 144552 4.) = cecee ene eee ee re 38 Seasonal ‘history:at. Tempe, Ariz: . 2.122.352 52-a¢e-- = ee 730) Hipemation seit el a ee nee eee ee 2. Ue 39 Notes on occurrence. oo... 204. DSS ee i ee ce ee ee 40 Natural. control: .. 2. 225-2222... 940. eae ee AALS oc. 02 ekg OE ee re oe ee ioe So 40 Natural enemies... 0055. 20001230 seo ee ee ee 4] Artifieial-comtrol a: tc Race ee es ee 2 ole? ie 42 Cultural methods. 4 (2 Se. eee ee ee a oa 42 Spraying. oo. 2.222 sce he ee a 43. Distribiutie the parasites.” o 2.) = ea2ce ese gene See tc ee 44 Bibliography. 252. k ee ee A 268200 44 Index: q.. . co eee OS ee eS oe tae Sig rene AT ILLUSTRATIONS: Page Fie. 1. Side view of the head of a thrips, showing the mouthparts. .......... 8 2. The bean thrips (Heliothrips fasciatus): Adult female and details... ... 9 3. The bean-thrips: Mees. 21... 2 abs. est oe ee ee 10 4. The bean thrips: First-stage larva. ........ MPTP en 11 5. The bean thrips: Second-stage larva. =... 2. ...5,2.248 sate eee 12 6. The bean thrips: Prepupasso.. ses eee \ secs dee ee eee 12 7. The bean thrips: Papas. 2.252.232 ae eee eee 13 8. Map showing present known distribution of the bean thrips (Heliothrips fascaltis) _. 923.2 2s. ee eee eee 15 9. Alfalia showing injury by the bean thrips-.....-..225. 2-225. see 29 10. The bean thrips: Prepupe parasitized by Thripoctenus russelli......- 4] 11. A hymenopterous parasite, Thripoctenus russelli: Adult..........-.-- 42 fre BEAN THRIPS. (Heliothrips fasciatus Pergande.) INTRODUCTION. In the State of California during the past four or five years the bean thrips has been reported with increasing frequency as a_serious pest to various crops. The common name “ bean thrips ” is somewhat of a misnomer, as this insect feeds on many different crops, but is re- tained here, as it is well known by that name in California. That State, with its long, dry summer, furnishes climatic conditions un- usually favorable to the development of thrips, and several species have gained such a foothold there as annually to cause a loss of hun- dreds of thousands of dollars. In the summer of 1909, Mr. R. 8S. Woglum, of the Bureau of En- tomology, informed the author that during the summer before he had seen hundreds of acres of beans in southern California so seriously infested by the bean thrips that they had the appearance of plants scorched by fire; and as this thrips seemed to be increasing in num- bers and destructiveness it appeared to be the part of wisdom to obtain all possible information concerning its life history and control before it reached the enormous abundance of the destructive pear thrips (Luthrips pyri Daniel). When, therefore, the Bureau of Entomology established a field station at Compton, Cal., in Septem- ber, 1909, for the study of truck-crop and sugar-beet insects, the writer planned, among other projects, to undertake as complete a study of this insect as time would permit. With this in mind, the bean thrips has been the subject of thorough investigation during the years 1910 and 1911. During this time, however, the insect was not again so destructive to beans, so that remedies with spray mixtures could not be thoroughly tested. Nevertheless, as the life history has been worked out and a large fund of information obtained on the dis- tribution and habits of this thrips, together with knowledge of a natural enemy of some promise, this paper is published at the present time. At Compton, in Los Angeles County, where the life history of this insect was studied by the writer, the temperature is quite cool, since the location is near the coast. 7 8 THE BEAN THRIPS. In the Imperial Valley the life history of the bean thrips and its injuries to alfalfa and cotton have been investigated by Mr. V. L. - Wildermuth, of this bureau, and where his observations are used credit is given in the text.t_ Use has been made of observations, by Messrs. P. R. Jones and S. W. Foster, of this bureau, on this insect in the more northern points in the State. Since July, 1911, the writer has been ably assisted by Mr. John E. Graf. He also wishes to ex- press his appreciation to Dr. F. H. Chittenden, under whose direc- tions he has conducted the investigation, and to Prof. F. M. Webster for the free use of notes obtained by his agents. NATURE AND EXTENT OF INJURY. The damage caused by the bean thrips is not confined to the foliage, but affects as well the fruit and stems of the plant attacked. The injury is caused by the method of feeding. Both young and adults obtain their food by puncturing the leaf tissue with their sharp mouthparts and, after lacerating it, with- drawing the plant juices at the point of attack. Figure 1, although a drawing of a different species, gives an idea of the mouth- parts of this insect. Each time as the contents of the leaf at the point attacked are removed, the thrips moves to a new point and repeats the opera- tion, so that if the insects are abundant or “eee the attack is long continued the leaf tissue is Pa eae a oie destroyed over the entire surface. As the the mouthparts. Much en- supply on one side of the leaf is exhausted larged. (After Moulton.) i the larve: move around to the other, or if adults are present these fly or jump to more tender leaves. The infested and badly injured leaves turn yellowish or white, dry up, and either drop off or hang lifeless to the plant. Then, as the attack continues, successive leaves are attacked until in extreme cases the entire plant is killed. DESCRIPTION. Heliothrips fasciatus belongs to the Suborder Terebrantia and the Family Thripide of the Order Thysanoptera, being placed in this position because of the downward-curved ovipositor of the female. The 8-segmented antenne, with the last segment much longer than the 7th, and the reticulated surface of the body, together with the pointed spines on the wings, place this insect in the Genus /elio- 1Mr. Wildermuth studied the insect in its relation to alfalfa, without knowing that it was being investigated by the author. His studies, made under quite different climatic conditions, add materially to the value of the results obtained. ea i i te DESCRIPTION. 8) thrips. The habits of the larva are also quite characteristic of this genus, for the habits of the larve of the greenhouse thrips (/elio- thrips hemorrhoidalis Bouché) and of Heliothrips rubrocinctus Giard are almost identical with those of the present species. THE ADULT FEMALE. The adult female (fig. 2) is about one-twenty-fourth of an inch in length (0.9815 mm. to 1.1174 mm.; average, 1.0405 mm.) and about one-fourth as wide as long (0.2265 mm. to 0.2869 mm.; average AN ‘a ) E> Ce = 7 Fic. 2.—The bean thrips (Heliothrips fasciatus): a, Adult female; b, ventral side of abdominal segment of same; c, antenna of same. a, Greatly enlarged; 0, c, more enlarged. (Original.) width, 0.2529 mm.) and is fusiform in shape. The head and body are black and, under the microscope, are seen to be covered with distinct reticulations and short white hairs. The antennz are 5- segmented and two and one-half times as long as the head, and are held out in front of the body. They are black, more or less banded with white, and bear white hairs. The wings are held folded to- gether down the middle of the dorsum; they are black, crossed by a white band at the base and a white band at three-fourths the dis- tance from the base. The wings are fringed with long white hairs. The legs are black, banded with white.' 1For a detailed description of the genus and the species for use of systematists, see Hinds’s “ Monograph of the Thysanoptera™ (Proc. U. S. Nat. Mus., vol. 26, 1902), pp. 174-175. 51097°—Bull. 118—12——2 10 THE BEAN THRIPS. THE ADULT MALE. The male resembles to a great extent the female, as the color and the markings are the same, but it is noticeably smaller in size and apparently more active. When viewed under the microscope the sexual organs are seen to be distinctly different, and in light- colored or cleared specimens the testes may be seen as two orange-red bodies in the abdomen, and on the middle of each of segments 2 to 6 on the ventral side are yellowish oval spots. The total length of the male is 0.7097 mm. to 0.8002 mm.; the average, 0.7474 mm. The greatest width across the mesothorax is 0.1963 mm. to 0.2114 mm.; the average, 0.1978 mm. RECENTLY EMERGED ADULTS. Both sexes, when just emerged, have the head and thorax a light yellowish orange, with the eyes and ocelli bright red. The antennz are white and ringed with brown, while the wings are dusky, crossed by bands of a darker color. The legs are white, with ends of each segment more or less black. Gradually the color darkens, and in a day they all have the fully matured colors, as described above. _ THE EGG. Fic. 3.—The bean thrips: The egg (fig. 3) 1s bean shaped, 0.21 to eee ae enlarged. 9 955 mm. in length and 0.105 to 0.12 mm. in | width, and is very delicate and thin shelled. It is translucent white, with a smooth shining surface. The eggs are laid in the tissue of the leaf or in the veins, or even in the stems, and in case of beans may be laid in the pods themselves. As the embryo within develops, the egg becomes swollen, and the little pocket in which it is inserted becomes raised above the leaf surface. The eggs may be seen in the leaf tissue if examined with a hand lens before the light. Each little egg pocket stands out, because of its lighter color, and within the crude outline of the egg may be seen. The younger stages of this insect differ distinctly from those of Heliothrips hemorrhoidalis* in the dashes of crimson so generally present on the sides. THE FIRST-STAGE LARVA.” (Fig. 4.) Length, 0.42 mm.; width of mesothorax, 0.135 mm. General shape fusiform, bd similar to Heliothrips hemorrhoidalis ; head, antenne, and legs large in propor- 1 For description of Heliothrips hemorrhoidalis, see ‘‘ The Greenhouse Thrips,” Bul. 64, Part VI, Bur. Ent., U. S. Dept. Agr., pp. 46-48, 1909. 2 Description made while larva was very young and before feeding commenced. DESCRIPTION. 11 tion to rest of the body. Color translucent white. Head large, quadrate; eyes reddish; ocelli absent. Antenne 0.195 mm. in length, apparently 7-segmented ; basal segment cylindrical, short; second nearly twice as long as first, barrel- shaped; third and fourth spindle-shaped, ringed with a few fine hairs; fifth, sixth, and seventh slender, nearly equal in length. Legs translucent white. Abdomen tapering posteriorly; first eight segments nearly equal in length, last two segments longer than others; each abdominal segment with longitudinal rows of setz, the tenth with four setz about 0.045 mm. in length. At this stage there seems to be nothing to distinguish this species from H. hamorrhoidalis. THE SECOND-STAGE LARVA. (Fig. 5.) Length, 1.05 mm.; width of mesothorax, 0.27 mm. Shape fusiform, about same as larva; of mesothorax and metathorax long, robust, cylindrical; sides of mesothorax and metathorax and first five abdominal seg- ments nearly parallel; pro- thorax narrowed toward head; last five abdominal segments tapering to the last segment, which is cylindrical and trun- cated at end. Color of head and prothorax light yellow, mesothorax and metathorax and first six segments of abdo- men translucent white, stained on sides with crimson blotches and with yellow on dorsum to some extent; next three seg- ments of abdomen the color of head, last segment of abdomen white; alimentary tract plainly indicated by the brownish color given it by inclosed food. Surface of body covered with minute granulations. Head quadrate, rounded in front and notched behind the eyes, 0.12 mm. long, 0.0825 mm. wide; eyes small, reddish: ocelli absent. Antenne 7T-segmented, first four segments the color of head, the others translucent white; first segment short, cylindrical; second longer, barrel-shaped; third and fourth spindle-shaped and annulated; fifth, sixth, and seventh slender and cylindrical. Legs long, yellowish. Abdomen 0.60 mm. in length, fusiform, ovipositor not formed; seg- ments with rows of fine sete increasing in length toward posterior end; ninth and tenth segments with longer seti. Vic, 4.—The bean thrips: First-stage larva. Greatly enlarged. (Original.) 1, THE BEAN THRIPS. THE YOUNG NYMPH OR PREPUPA. (Fig. 6.) Length, 1.02 mm.; width of mesothorax, 0,255 mm. Shape fusiform, similar to adult. Head, length, 0.09 mm.; width at eyes, 0.157 mm. Head translucent white, vertex slightly yellowish, ocelli absent. Head rounded in front, slightly notched behind the eyes; eyes red, made up of a few facets, surface faintly reticulated ; two pairs of sete behind the eyes and two pairs between the eyes. Antenne translucent white, extending forward, 0.195 mm. in length; segments indistinct but apparently 7-segmented. Prothorax about one-half again as wide as long, sides rounded, posterior edge broadest, semitranslucent white to yellow, posterior angles tinted with crimson, Fic. 5.—The bean thrips: Second- Fig. 6.—The bean thrips: Prepupa. stage larva. Greatly enlarged. Greatly enlarged. (Original.) (Original.) setze around margin. Mesothorax with rounded angles, translucent white to faint yellow, sides and posterior angles tinted with crimson, wing-cases trans- parent white, distinct from each other, those of forewings extending to middle of second abdominal segment and those of hind wings extending to middle of third abdominal segment. Legs strong, translucent white. Abdomen fusiform as in adult, translucent white to faint yellowish, edges with tint of crimson, which enlarges to fair-sized blotches on sides of seventh and eighth segments; number of longitudinal rows of set# increasing in length toward posterior end. Length of abdomen, 0.62 mm. DESCRIPTION. te THE FULL-GROWN NYMPH OR PUPA. (Fig. 7.) Length, 0.99-1.09 mm.; width at mesothoracie angles, 0.24-0.255 mm. Shape similar to that of adult. Color orange; posterior border of prothorax, mesothoracic angles, sides, and abdominal segments 2, 3, 6, and 7 more or less erimson. Head, length, 0.11 mm.; width, 0.18 mm.; orange, apparently faintly reticulated; eyes dark red, larger than in prepupal stage, facets small. Three ocelli present in close triangle between eyes, in color yellow. Antenne laid backward on head and reaching to beyond middle of prothorax; segments in- distinct, translucent white; segments 1 and 2 projecting in front of the head and 2 with four sete or hairs, two extending forward, about 0.01385 mm, in length. Tho- rax light orange or yellow. Prothorax about twice as wide as long. Wing-cases 0.54 mm. long, extending to seventh abdominal segment, translucent white. length from head to end of wing- pads, 0.825mm. Legs trans- lucent white. Abdomen fusiform, similar to adult, surface plainly reticulated in older specimens, sete weil developed, the longest ones at posterior end. Length of abdomen, 0.612 mie wick, 0.31 mm.; length of posterior sets, 0.085 mm. The younger stages of this insect differ distinctly from those of H. hemorrhoidalis? in the dashes of crimson so generally present on the sides. [ f ae [ / A : ee eke Se ws” ce I nis tae Leet ; ~ The pupa of the male is shorter and more slen- der than that of the fe- Fig. 7.—The bean eke Greatly enlarged. male. This pupa differs Panera from 1. hemorrhoidalis in its smaller size, in its yellow color, with the sides of the abdomen more or less stained with crimson, and in having the hairs of the body longer and the second segment of the antennee with two long sete. The foregoing descriptions are for the parts of California in Los Angeles County and more northern points, for Mr. Wildermuth ‘For description of Heliothrips hamorrhoidalis, see “The Greenhouse Thrips,” Bul. 64. Part VI, Bur. Ent., U. S. Dept. Agr., pp. 46-48, 1909. 14 THE BEAN THRIPS. found that the different stages in the Imperial Valley lacked the red markings except in the cooler weather of the late fall. ORIGIN AND DISTRIBUTION. This insect was first described by Mr. Theodore Pergande from specimens taken in Yuba County, Cal. A few years later he identi- fied a thrips from Lewiston, Idaho, as this same species. Mr. Dudley Moulton reported that this species had been collected in Colusa County by Mr. E. K. Carnes, in Santa Rosa County by Mr. O. E. Bremner, and in the Santa Cruz Mountains, Santa Clara’ County, by himself. Mr. D. L. Crawford recorded fasciatus from Santa Paula, Ventura County, Cal., and from Claremont and Chino, Cal. Mr. William B. Parker, of this bureau, collected it at Davis and Hamilton City, Cal. Mr. P. R. Jones, engaged in pear thrips in- vestigations, reports that this insect occurs very commonly around Lindsay and San Jose, Cal. Mr. 8. W. Foster, while engaged in the same investigation, collected this insect from Martinez, Cal., and later found it “ frequently throughout Contra Costa County.” Mr. V. L. Wildermuth, engaged in cereal and forage insect in- vestigations, has collected this insect in California at Indio, River- side County, and at Bard, El Centro, and Holtville, Imperial County, and in Arizona at Yuma, Yuma County, Buckeye and Tempe, Mari- copa County, and Sacaton, Pinal County. During the present investigation the writer has collected this insect quite extensively from many places in southern California. In 1910 it was found to be very abundant on wild lettuce in several yards and alleys in the city of Los Angeles itself. At various times it has been collected from Bell, Compton, Gardena, Glendale, Holly- wood, Laurel Canyon, Puente, San Gabriel, Sierra Madre, Tropico, and Whittier, in Los Angeles County. In Laurel Canyon the author found it feeding on wild food plants in uncleared land about 6 miles from cultivated fields. It was also collected near the entrance of the canyon, scattered over the mountain sides on various wild plants. At Sierra Madre it was taken at an elevation of 750 feet. It was also collected at Garden Grove, Huntington Beach, Smelt- zer, and Sunset Beach, in Orange County, Cal. While on a trip in October, 1910, the author found this insect to be generally distributed throughout the town of Oxnard, and in Montalvo and the entire outlying sugar-beet district of Ventura County. : In February, 1911, the author made a trip to San Diego to investi- gate the conditions in reference to truck crops there, and in Mission Valley—a long, narrow, and fertile valley lying to the north of San Diego, and devoted to truck crops—this insect was found feeding to some extent on pea vines. The writer left California for Washing- ton, D. C., in September, 1911, and while delayed at Sparks, Nev., he examined several clumps of wild lettuce growing along the rail- ORIGIN AND DISTRIBUTION. 15 road track and collected both larval and adult forms of the bean thrips upon this plant. Mr. A. C. Morgan, of this bureau, recently reported to the writer that he had collected the species on October 10, 1910, at Clarksville, Tenn. The fact that this insect is so widely distributed in all parts of California seems to point strongly to that State as its original home. This is also strongly supported by the fact that Moulton collected it from wild vetch in the Santa Cruz Mountains and that the writer collected it in wild, uncultivated tracts in the mountains and canyons north of Los Angeles, 5 and 6 miles from cultivated crops. This point of view is further strengthened, because the au- thor has found this insect feeding on more than 20 native wild ! \ ene MISS. ALA. \ GA. Fig. 8.—Map showing present known distribution of the bean thrips (//eliothrips fasciatus). (Original. ) Mr. J. D. Hood, formerly of the office of the State entomologist of Illinois, recently informed the writer that he possessed specimens of this thrips that were collected by Prof. Lawrence Bruner at Lincoln, Nebr., February 14, 1899, and that he had collected this same species at Urbana, IIl., in March, 1907. In both cases the thrips were taken on California oranges and had evidently been car- ried across the country while hibernating in the navel end of the fruit. This is an excellent illustration of how this insect may be distributed through the agency of man. Although this insect is quite minute and has been little studied, at the present time it is known to occur through the entire State of California, in several places in Arizona, in Nevada, and in Idaho near the Washington State line. It has also been found in one locality in Tennessee. Figure 8 has been prepared to show the present definite localities where this insect has been observed. 16 THE BEAN THRIPS. Without doubt this insect occurs over the entire Pacific coast of the United States and down into Mexico for some distance and pos- sibly even into Central America. As it becomes better known it will probably be found to occur in several of the other Western States and some of the Eastern States as well. “HISTORY. In 1895 Mr. Theodore Pergande (1)? described this species from one specimen received from Yuba County, Cal., where it was taken on an orange leaf infested with (Aspidiotus) Chrysomphalus aurantii Mask. At that time he expressed the opinion that the occurrence on this plant was accidental. In view of our present knowledge, however, of the feeding habits of this insect, this specimen was probably feeding on the folage of the orange itself. In 1902 Hinds (3) redescribed the female from one specimen in the collection of the Bureau of Entomology. At that time he wrote that nothing was known of the life history. Miss Daniels (4), writing in 1904, noted the occurrence of this thrips in California. At the same time she erected a new genus and species, Caliothrips woodworthi (4), for the male of Heliothrips fasciatus. ‘This error was first pointed out by Dudley Moulton (6) in 1907, and the present writer agrees with him, as the male of fasciatus fits the description exactly except in the number of an- tennal segments. Undoubtedly Miss Daniels made a mistake in the number of segments inthe antenna, since fasciatus is 8-segmented only. Crawford (7), in 1909, under “ Notes on California Thysanop- tera,’ records taking numerous specimens in southern California. These were captured on pine, Lotus glaber, and apple. Under the name Futhrips fasciatus, Bremner (8), in 1910, reported this insect as injuring beans and peas and as occurring on alfalfa and on peach and pear trees. He recommended spraying with nico- tine solutions, and wrote that of these sulphate of nicotine in the proportion of 1 ounce to 5 gallons of water had given perfect success. : In 1911 Coit and Packard (9) wrote that the bean thrips caused considerable defoliation to cotton and alfalfa in Imperial Valley, Cal. Moulton (10) also gave a list of its food plants. The present writer, in 1911 (12) and also in 1912 (13), published two papers dealing with the life history and habits of Thripoctenus russelli Crawf., a parasite reared in large numbers from this thrips. RECENT RECORDS. This species, as identified by Mr. Pergande, was sent to the Bureau of Entomology January 25, 1898, by Mr. M. J. Wessels, of Lewiston, 1 Numbers in parentheses refer to the Bibliography, pp. 44-45. HABITS OF THE ADULT. 17 Idaho, who collected it in a diseased spot of a crab apple. On August 27, 1908, Mr. I. J. Condit sent in specimens of this thrips from Davis, Cal., where they were injuring sugar beets. He wrote: — I examined the beets and found them literally covered with thrips, both the surface and underside of the leaves being badly infested. There were very few leaves which were not attacked, most of them having the appearance of the specimens sent. A field of tomatoes near by was also becoming infested. The lower leaves especially were yellow and some falling off. Mr. S. W. Foster informed the writer that on August 26, 1909, Mr. Frank T. Swett, of Martinez, Cal., sent to the laboratory of the Bureau of Entomology at Walnut Creek, Cal., a quantity of pear leaves badly injured by this species. On August 31 Mr. Foster visited the orchard and found the injury quite noticeable. He wrote that “the foliage gave the appearance from a distance of having been scalded.” Mr. V. L. Wildermuth, of this bureau, sent speci- mens taken on alfalfa at Indio, Cal., on July 2, 1910. Mr. A. McLachlan, of Davis, Cal., sent in specimens of this thrips on October 13, 1910, with the report that they were injuring the buds and tips of cotton. Mr. W. B. Parker, of this bureau, under date of August 25, 1911, sent this insect from Davis, Cal., with the statement that it was causing serious damage to the foilage of the sugar beet. He also collected it on sugar beets at Hamilton City, Cal., on September 18, 1911, where it was causing some injury. He wrote, however, that: owing to the lateness of the season when the beets were attacked probably only slight damage resulted. HABITS OF THE ADULT. For a short time after emerging from the pupa this insect remains quiet and appears to be waiting for its limbs to harden. During this time the colors, which were light at emergence, gradually darken. A fter hardening the thrips moves off and begins feeding. METHOD OF MATING. The males and females of this species seem to emerge from the pupa at about the same time. During this investigation it was ob- served that, under laboratory conditions at least, the sexes mated generally in from two to three days after emergence and in some cases in even less time. This operation has been observed both in the field and in the laboratory and was identical under both condi- tions. This is probably best described by the original field notes male at the time of observation. 51097°—Bull. 118—12—3 18 THE BEAN THRIPS. The male,t when inclined to copulate, picks out a female, and if she 1s moving over the leaf runs after her and jumps or alights on her back. In some cases he then spreads the wings and moves them up and down, at the same time moving the tip of the abdomen in the same manner. In other cases the male, after leaping onto the back of the female, remains motionless for some time in that position. It then exserts the copulatory organs from the tip of the abdomen and shifts around toward the side of the female, at the same time bend- ing the abdomen under to the ventral side of that of the female. The copulating organs are then moved back and forth until they en- counter those of the female. In some cases observed, when the male did not succeed in connection, it would withdraw to its former posi- tion on the female and after remaining quiet for a short time would move over and attempt the act on the opposite side. As soon as con- nection is made the male remains motionless for a short time, during which period the female, in many cases, crawls slowly around on the leaf. After a few minutes the male relinquishes his hold with the copulating organs and moves squarely back onto the dorsum of the female. Soon after the male crawls off and away from the female. This entire operation was observed in three cases to occupy 3, 5, and 10 minutes. Several cases were observed where two males attempted copulation with the same female, but, after a vain atlemay one generally left her. METHOD AND TIME OF OVIPOSITION. Exactly how much time elapses between copulation and oviposition was not observed, but probably not more than a day, so that the female will begin oviposition within three days from the time she emerges from the pupa. In one case adults emerged on July 19, 1911, and eggs were laid four days later. Oviposition usually takes place during the night, but has been observed at 2, 3, and 4.30 in the afternoon. A female engaged in oviposition was observed to crawl over the leaf of the food plant for a short distance and then to stop and scrape a hole in the leaf with her mouth cone. This was accomplished by a slight forward and backward motion like that of a chisel. In a short time the female ceased this action and moving forward until she could place the tip of the abdomen where the ‘tissue had been ruptured, arched the abdomen in the middle, and brought the tip to the opening in 1 Pietro Buffa (Atti Soc. Toscano Soc. Nat. Mem., vol. 23, p. 48, 1907) figures Wolothrips fasciatus, female and male in copulation, in a position identical with that observed by the writer in Heliothrips fasciatus on many different occasions. A. F. Shull (A Biological Survey of the Sand Dune Region of Saginaw Bay, Mich., pp. 190-192), describing copulation in the suborder Terebrantia, expresses doubt as to the position of the male on the back of the female during copulation. As his observa- tions on Huthrips tritici were made under unfavorable conditions his conclusions were probably erroneous. HABITS OF THE ADULT. 19 the leaf surface. She then proceeded to work the ovipositor back and forth in the rupture until she had made an incision of sufficient depth. After this she became motionless for a varying length of time, while the egg was being deposited, whereupon the ovipositor was removed, and the female moved away. A number of cases have been observed where the female, after inserting the ovipositor, could not withdraw it, and, thus held, she ‘soon died. NUMBER OF EGGS AND PERIOD OF OVIPOSITION. Owing to the artificial means used in studying the habits of this insect it was impossible to determine exactly how many eggs a female is capable of laying. However, the writer confined 6 fe- males in a vial for observation. They laid an average of 35.5 eggs each, while the highest average for any day was 5.5 eggs each. Another female, during the period from August 16 to August 23, 1911, laid 16 eggs, the greatest number laid in any one day being 5. At Compton, Cal., during 1911, females kept in confinement were observed. to oviposit for 30 days in succession, while others were observed to oviposit 51 and 83 days after they emerged from the pupe. If this insect normally continues oviposition regularly over 2 period of 83 days the total number of eggs laid must be very large. Mr. VY. L. Wildermuth, while in the Imperial Valley, made some interesting notes on the number of eggs this species may deposit. On August 2, 1910, he confined 2 females on leaves of alfalfa in a vial, and on August 5 these leaves contained 50 eggs, or an average of 25 eggs each in 38 days. His other observations are given in Table I. . TABLE I.—Nuwmber of eggs deposited by the bean thrips (Heliothrips fasciatus), Imperial Valley, Cal., 1910. Date and number of eggs. Total ae Date female period of ed N was put in vial. Oviposi- fee _ 1910. | Eggs.| 1910. | Eggs.| 1910. | Eggs.|Dead.| tion. | 9 ©88S- | 1910. Days. Ae. 29.05... Sept. 1 36 | Sept. 2 6 | Sept. 6 37 2 7 79 ie Oe) Sept. 4 co ee cata ramen ieee] (ae ery a at 3 42 es Does. .| Sept. if SEAM Le Sea a ae fil a eae a eee 6 53 2 | eee Qe es ton x Sept. 1 A) eee ra rneere mes rare Bit r. Wae Se cl ack eaek. 1 20 1911. 5 | Sept. 281...... Sept. 30 12°) Oct. 3 2 | Octs = 1 24 | Oct. 21 1 el ES eer Pe seach, ADS cyan 46 134 foNGve, J 27 | Noy. 11 11 1 Record made at Tempe, Ariz. In these experiments the longest period of oviposition was 46 days, and the largest number of eggs laid by a single female, 154. It will be observed from these figures that the females observed by Mr. Wildermuth deposited more eggs and at a more rapid daily rate 20 THE BEAN THRIPS. than those observed by the writer. This may have been due to the higher temperature of the Imperial Valley and vicinity, where his . observations were made. Mr. Wildermuth noted adults in copula- tion the day that they emerged, and oviposition on the following date. He also observed this species to oviposit during the entire day, whereas the writer never observed it to oviposit except in the after- noon or night. PROPORTION OF THE SEXES. The bean thrips was under the observation of the writer for a period of more than two years, during which time it had been ob- served in the field at all times of the year. In all observations made during the investigation of this insect the males and females were collected together and copulation was observed from early in Febru- ary until reproduction ceased late in the fall. - Apparently the females outnumber the males, but this may be due to the fact that the females are not quite so active as the males, and are not dis- turbed on the plants when examined. On June 9, 1911, out of 17 specimens reared in the laboratory 9 were females and 8 males. July 17, 1911, the writer examined another series of live adults that were reared in the laboratory. Out of 106, 80 were females and 26 males. A third series of reared adults was examined October 16, 1911, and out of 44 adults 32 were females and 12 males. Apparently the per- centage of females is too high and does not indicate the exact rela- tion between the sexes. ; ; KINDS OF REPRODUCTION. In all observations made on this topic reproduction has been bisexual, and in view of the fact that males were observed at all times and copulation also occurred at all times in the year when this insect was active, this would seem to be the usual method. How- ever, although the few experiments made to determine whether parthenogenesis occurred gave negative results, in view of the pre- ponderance of females during certain parts of the season it is quite probable that asexual reproduction may occur. It would seem that this method would occur under certain conditions, especially in view of the fact that the greenhouse thrips (Heliothrips hemorrhot- dalis)* reproduces, so far as we know, asexually only, the male hav- ing never been discovered. FEEDING HABITS. Both the adult and larva of this thrips injure the host by feeding on the foliage. As in the case of the greenhouse thrips, the lower 1“ The Greenhouse Thrips,’ Bul. 64, Bur. Ent., U. S. Dept. Agr. HABITS OF THE ADULT. at and earlier leaves are first attacked in the spring by the adults. These feed on the underside of the leaves, scraping out the leaf content in small spots that become white and conspicuous. Often the adults move along and leave a chain of white spots to mark their progress. The adults also feed to some extent on the surface. As they feed the females deposit their eggs in the leaf tissues, and as soon as incubation is completed the larve hatch and join the adults on the leaves. Under these conditions the leaves become more or less dried and lifeless, and the adults move to the higher and more tender leaves of the plant. In this way the entire plant may become infested. On February 5, 1911, the writer found the adults of this insect extremely abundant in the pea field of some Chinese truckers at Hollywood, Cal. Here nearly every plant had 7 or 8 adults feed- ing on the underside of the foliage, and in many cases 5 and 6 were present on each leaf. On August 18 of the same year in the same locality plants of spiny wild lettuce (Lactuca scariola) were observed that had 50 adults feeding on a single leaf. The adults seem to feed on a large variety of plants and have been found feeding on all of the plants given under “ List of food plants.” It may be well to state at this point that the presence of adults on a plant has not been considered sufficient evidence to class that plant as a food plant, but whenever larve of this insect were taken on a plant, this was considered sufficient to rank the plant as a host. In the spring when the adults leave hibernation they collect on the wild food plants present and feed on them until their injury, due to an increase in numbers and feeding, weakens the plants and shortens the food supply; then they fly to fresh plants of the same hosts or to cultivated crops and fruit trees nearby. Of all the food plants observed, the spiny wild lettuce (Lactuca scariola) seems to be the most favored. This plant has been found to be infested more heavily than any of the other food plants concerned, not excepting those of economic importance. FLIGHT. The present writer in his investigations of the greenhouse thrips ? never observed that insect to take flight naturally, or even when dis- turbed. The adults of Heliothrips fasciatus, on the contrary, take flight very readily, and if jarred or disturbed will usually fly or jump. This species in taking flight raises the tip of the abdomen quickly, and separates the wings. It then rises straight up into the air and flies rapidly away in short undulating curves. Indeed, to the un- trained eye it appears, in flight, exactly like a small speck of soot being blown around by a slight breeze. This power of flight aids greatly in the dispersion of this insect during the spring and summer. 1 Loc. cit. oo THE BEAN THRIPS. LEAPING. This species possesses the power to leap actively and, considering its size, to a considerable distance. It is no uncommon occurrence for the specimens which are being examined upon a plant to leap off and be lost. Like the greenhouse thrips, it will crawl over the leaves rapidly when disturbed. At other times it will remain motionless for a considerable period, lying closely to the surface of the leaf along one of the veins. NORMAL LENGTH OF LIFE. The length of life of this insect as an adult has been determined under the artificial conditions of confinement in vials containing fresh leaves of the food plant. As often as these lost their freshness other leaves were put in and the adults were changed with a camel’s- hair brush. : Even under these conditions the length of life observed for some individuals was surprisingly long, when we consider the minute size of the insect. During these experiments it. was observed that these insects were very sensitive to humidity or a lack of it and all were soon killed whenever the vials used in confining them became too dry. Table II shows the results of these experiments in which some thrips lived for 84 days. Taste Il.—Length of life of adult bean thrips at Compton, Cal., 1911. Specimens died. \ P Last Maximum Date adults emerged from pupa. EO —————— adult length of emerged. : : " Date. |Number.| ed. fe iE 3 / Days. : ay : PMO TUAGY 2 Sac ie cee eee oe aeane teens cee eee eee ee 3 {May rl 1 \wray 22 37 May 8 { i JNg op etl COR ies aeeiene sail toes ae Meg etn ee Tere, eee Ve ue Dele 11 };May 18 1 |pJuly 143) 84 May 26 1 June 5 il é June 17 5 June 5 Soo noe ci See Cian eo eo aoe oe Soc eee ose Sos 9 frase 1 3 \aug. 14 F 71 July 22 2 July 25 2 J July 26 2 o SF La yl Os es Seek scte be See ee ene enews ge aes 14 Aug. 8 9 Aug. 21 34 Aug. 12 2 Aug. 17 a 1 Dead. 2 Lost. 3 Male and female. LENGTH OF LIFE IN WINTER. A number of adults were collected from host plants on November 18, 1910, and were placed in vials and furnished with fresh leaves at intervals, and some lived in confinement in this manner until Febru- ary 1, 1911, by which time all had died. On January 16, 1911, a num- es HABITS OF THE LARVA. Dae ber of adults were taken from the open on leaves of nasturtium and were placed in vials. These died in April, giving a length of life after being collected of 92 days. As adults have never been observed to emerge from pupz later than December 27, these adults must have been at least 21 days old when collected, so that they lived about 113 days. Probably hibernating individuals live as long as 5 months. HABITS OF THE LARVA. In observing the habits of the larva of this thrips, the writer was constantly impressed with the great similarity that existed between this species arid the greenhouse thrips. This is so great that the description of habits of the one would almost equally fit the other. — HATCHING. Apparently the hatching process may occur at any time during the day. Many have been observed hatching early in the morning and one larva was observed emerging from the egg cavity at 4.25 p.m. Very slowly this larva pushed its way out of the egg cavity,! during which time the appendages were all held closely appressed to the body and were invisible. As soon as the body was nearly out the insect began a slow forward and backward movement and at 4.40 p. m. all but the tip of the abdomen was free, while the larva pro- jected straight out from the leaf surface. While held in this position it began slowly to unfold the limbs and antenne and move them around. The motion was very feeble at first, but gradually the larva seemed to gain strength and at 4.48 p. m. it bent over and, grasping the leaf surface, began to pull with its limbs in order to free itself. This was accomplished at 4.53 p. m., making the total period required in emerging from the egg 28 minutes. The larve of this insect after hatching move away a short distance, then appear to rest for a few minutes until they become stronger. Within a short time, however, they move on and soon commence feeding. When first hatched the larve are very minute and almost colorless, but as they begin to feed and drain the green coloring matter from the leaf the alimentary tract becomes plainly visible from the contained food. In a few days the color of the body becomes more or less yellowish and blotched with crimson. In com- mon with other species of Heliothrips, the larve of the present species keep the tip of the abdomen elevated and carry around on it a small globule of reddish liquid excrement. Gradually this globule increases in size until it is too large to be carried any longer and it falls to the leaf surface. Here in time it dries and forms a black spot or scale. The occurrence of these spots on the leaf of a plant 17This larva emerges from the egg by the same method that is used by the conchuela (Pentatoma ligata Say) as described by Morrill (Bul. 86, Bur. Ent., U. S. Dept. Agr., pp. 38-39). 94 THE BEAN THRIPS. marked by feeding of some thrips furnishes good evidence that the bean thrips has been feeding there at some time. The larve feed in much the same manner as the adult, the mouthparts being practically the same. They gradually scrape out the contents of the leaf, leav- ing silvery spots, which as they become abundant often unite and | gradually destroy the vitality of the leaf. Most of the eggs seem to be laid on the underside of the leaves, although the writer has ob- served eggs to hatch from the upper side also. As a consequence the larvee begin feeding largely on the underside of the leaves. After hatching they do not move far before commencing to feed, during which time, under ordinary conditions, they move very little. When plants are first infested the larvae seem to feed close to the leaf veins, but as they become more abundant they scatter in groups over the entire leaf surface. Like those of the greenhouse thrips the larve of this species seem to cluster in colonies and unless disturbed, or in need of fresh food, remain thus. The colonies are in many cases found in between.two veins of the leaves. When disturbed the larvie will violently twitch the end of the abdomen with its drop of liquid and move away rapidly. Apparently this is used as a means of de- fense, for the writer, 11 work with a parasite of this thrips, observed at times that these larvee when touched from in front by the parasite flung the abdomen around and moved rapidly away. When this oc- curred the parasite generally retreated, but returned to the attack and later usually succeeded in ovipositing in its host. The larve and adults of this thrips feed together in colonies, and as the leaves become crowded or dry from excessive feeding the larvee move in search of fresh food. Gradually the whole under- side of the leaf attacked becomes infested by the larve and then the surface as well. In fact, the writer has seen leaves so heavily infested by the larve of this thrips as to give them a decidedly . larvee move in search of fresh food food. Gradually the whole under reddish color, due to the bodies of the insects. So far this larva has not been observed feeding in the blossoms of any plant, but in some cases it has been observed feeding on green tomatoes, and when bean vines are badly infested the pods are also attacked. Indeed, when excessively abundant, these insects will not only cover both sides of the leaves, but the stem of the plant as well. The larve as a rule feed unprotected on the leaf, but at times may be found feeding under the protection of red-spider webs. Apparently these minute creatures are not affected by dust, as the writer has found them feeding in large numbers on leaves of spiny lettuce in an alley in the city of Los Angeles when the leaves were so thickly covered with dust as completely to hide the surface. It would seem that with the enormous clouds of dust that arise in this section during the entire summer, completely coating the larve, they would speedily succumb. HABITS OF THE LARVA. 25 As an illustration of how abundant this insect may become, the following observations are given: On August 31, 1909, Mr. Foster, of this bureau, found it severely infesting pear foliage at Martinez, Cal., and noted as many as 200 larve on one side of a leaf. On July 28, 1910, the writer found some plants of spiny lettuce badly infested by the larve of this thrips, and 10 leaves gave a total infes- tation of 733. (See Table III.) This gave an average of 73.3 to each leaf. TABLE III.—IJnfestation of Lactuca scariola by larve of the bean thrips. | Number | Number Total Number | Number]! Total No. of | of larvee | of larvee |numberof}| No. of | oflarvee | of larvee | number leaf. | onunder | onnnper| larve leaf. | on under | on upper | of larvee side. side. on leaf. side. side. on leaf. 1 70 a dit 7 44 47 91 2 34 39 73 8 61 30 91 3 2 45 9 70 if 71 4 3 2 10 23 Si, 55 5 59 47 106 6 46 46 92 480 253 733 On July 18, 1911, at Hollywood, Cal., leaves of spiny lettuce were found that had several hundred larve toa leaf. September 22, 1910, Mr. Wildermuth observed a field of cotton at El Centro, Cal., show- ing considerable injury by this insect, and counted as many as 200 larvee to a single leaf. MOLTING. The larva molts once, giving two larval instars, then molts to the prepupal stage. On July 28, 1910, a number of larve that had just hatched were separated and on August 2 these all molted. On August 7 they again molted and changed to prepupe. This gave the first instar a length of five days and the second a length of five days. The process of molting in the larva is continued unprotected in the midst of the feeding colony. After molting the skin is left adhering to the leaf beside the feeding larva. It was observed with the larvee of this species and of those of the greenhouse thrips that when they were exposed to a low temperature the entire development was checked and growth remained stationary during the exposure. In long-continued exposures the insects were killed, but if within three weeks they were again removed to higher temperatures the larve resumed their growth and pupated in a few days. ; | Under the artificial conditions of rearing in vials the mature larvee seek concealment before pupation in curled-up leaves, in all kinds of protected places, and if in vials closed with cotton plugs they work their way in between the plug and side of the vial. In the field, however, the larvae when full grown desert the plants and hide in rubbish and cracks in the ground or beneath clods of earth. 51097°—Bull. 118—12—-4 26° THE BEAN THRIPS. The molting from larva to prepupa under laboratory conditions has been observed many times. On April 10, 1911, a mature larva was observed to begin the process at 4.05 in the afternoon. After remain- ing motionless for some time it arched its body, and shortly after the skin split down the head behind the antenne. The head grad- ually forced its way out of the opening, then the body followed, the old skin being slipped off behind. This molting was completed at 4.21 p. m. HABITS OF THE PREPUPA AND PUPA. The prepupee of this insect are found in company with the pups and full-grown larvee in small social colonies. These hold the antenne out in front of the body and move about to some extent. The pupeze, however, carry the antennee folded back on the héad and thorax and remain motionless unless disturbed or exposed to the light, in which cases they will slowly crawl away. When com- pelled to pupate in ‘closed vials the prepupe and pupe occur in- large numbers closely packed together along the edge of the vial and the cotton plug or buried in the cotton itself. In nature it has quite different habits. While the greenhouse thrips under natural conditions pupates on the leaf of the food plant in among the feeding larvee, with the bean thrips this seldom takes place, and during the two years this species has been under observation by the writer only three pupx have been found on the plants infested by hundreds of thousands of larvee. In one case a pupa was found under the web of the red spider near the midrib of a leaf of spiny lettuce; in another, one was found under a web of red spider on a leaf of the wild tobacco flower; and the third was found in a curled-up lettuce leaf. | December 17, 1910, a quantity of the dead leaves of wild helio- trope were collected on the ground under infested plants. Prolonged sifting revealed the presence of a single pupa. In 1911, the prepupze and pups were found by Mr. John E. Graf and the writer to be very abundant in infested bean fields under clods or lumps of dry earth and in cracks or holes in the lumps. Upon exposure to the light these at once began to move away in search of darkness. Mr. Wildermuth also found the pupe of this insect underground. He wrote in his notes on September 28: While searching by aid of a binocular for pups, I found one pupa, one prepupa, and two (mature) larve just at the crown of the plant and beneath the soil; one pupa about cne-fourth inch below the surface of the soil in an oval cavity about three times as long as the pupa itself; one prepupa between a dead leaf and the soil. Never have I found a pupa above the surface of the ground, on the leaves of the plant, or between the sheath leaves and the stem, as frequently occurs in confinement. The molting of the prepupa to the pupal stage is very similar to that deser*bed for the change of the larva to the prepupa. It takes a ss ee FOOD PLANTS. oy place in whatever location the prepupa may be, and the transparent and delicate empty skin is found behind the pupa. It was observed during the fall that pupz exposed to a low temperature did not com- plete their development to the adult stage. These, when later placed in the greenhouse, changed to adults unless exposed to the unfavorable conditions too long, when all were killed. During the pupal stage several external changes take place. At first the ocelli are not evident, but as the pupa develops these become prominent in a triangle between the folded antenne. Then the reticu- lations of the body begin to appear, and within two days of the emergence of the adult the pupa begins to darken and the legs, antenne, and wings begin to show blackish bands. The adult emerges in a manner similar to the molting of the larva. Emergence has been noted at all hours of the day, and there seems to be no par- ticular time for its occurrence. FOOD PLANTS. This insect seems to be nearly as omnivorous as the onion thrips, as the following list of food plants upon which it has been reared or cbserved during the past two years by the writer would indicate. These have been divided into economic and wild food plants, and under each will be given notes on injury and appearance of injured plants. BEANS. The injurious occurrence of this insect on the foliage of beans gives toititscommon name. It has been observed by the writer to feed on bean foliage in the adult and larval stages from early in February, in sheltered places, until the plants are killed by frost in the fall. In the spring the wild plants are first up, and the attack is largely concentrated on them, so that when the beans come up they are not immediately attacked. However, in a few weeks the insect spreads to the beans, thereafter increasing in numbers until in the late sum- mer and fall much injury is done. When snap beans are infested the adults first attack the leaves, and while feeding lay countless eggs in the tissue. The larve on hatching begin to feed, and gradually the green coloring matter is entirely removed from the underside of the leaf. This becomes white and covered with the black spots of excrement. The infestation then spreads to the surface and to other parts of the plant. As the feeding goes on the leaves lose all color, become white, or dry up and turn brown and drop off. As the infes- tation increases, the stems and pods themselves are also attacked and ruined. 50 | July 13 3 | 3 | 1 lea po ge Pe ele Here the minimum for the larval stage was 11 days and the maxi- mum 14 days. In July larve were reared from eggs laid in normal growing plants, situated in an outdoor insectary under normal conditions. These experiments are all given in Table VII. TABLE VII.—Length of larval stage of the bean thrips in July, 1911, at Compton, Eggs hatched. Exp. No. Date. | Number. July 23 5 1 {July 24 54 July 25 16 July 24 26 2 | lee eee eee In the month of July these stages required from 1 to 4 days for the prepupa, and from 4 to 7 days for the pupa, or a total of from 5 to Li days. The number that required less than 7 days, however, was very small. During this month the average mean temperature was 69° F. Table IX shows the results of these experiments and the average temperature for each. SEASONAL HISTORY AT COMPTON, CAL. 35 oa IX.-—Length of prepupal and pupal stages of the bean thrips at Comp- ton, Cal., during July, 1911. Changed to Adults : Changed to prepupa. pupa. emerged. Length of stage. cera PE (es (ee eee _| mean NG. & is m ‘ tempera- um- um- um- re- 7 ture. Date. ie Date. onl Date. ber. | pupal. Pupal. | Total. Days. | Days. | Days. sb Beletolyet..s..-.-..... 7\ July 5| 7 {ru a hee 7 ae SA To St 71.7 Lothar 3 my a 3] July 18 3 3 5 8 u 4 6 ; i ne 7Hyue is] iipuly is] 7 3 7 70.1 int 3 {yun Fal, o | \Suly 19. | ste 1) Aa 5 {ruly LS Lo culver dy 1| July 24 1 2 7 9 \ 71.6 oT) hn 1| July 18 1| July 24 1 2 6 8 be ned Weer = at 2’ ay 45 ag this firipe. fliothvips neces Perg. is noted as one of the species affecting the LR DEAE ; Page Aiolothrips fasciatus, probable enemy of bean thrips.................---+----- 42 eeeeimacdwmlant Of bean thrips..............-.--+-.-5--2---+------- 16, 17, 28-30 nm Of Dean thrips. ....-.-.----5---ss4--0-- 2 ease cee e encase 16, 31 Seams tarips taken thereomw..-.....20.....-...-2-2----0+--++etaes V7 eee ned plant of bean thrips......-..--.- 05... 2-2-2. 0422-222 +e 31 ner ann OL Dean LOTips..2..-2...-.-2-. 2222.48 2-2. eee ee eee 16.27 neem mant Of bean thrips......-2..-...-.-202.---2.- bee. selene 17, 28 fame, iood plant of bean thrips........-...:---.--...-: yee ae ee 28 Mnemerrsm 1000 plant of bean thrips..-.......-¢--..--.-.-----2-2-+5-2-5- 31 Penner ait, of bean thrips.....---.--.5.-.-2-------- eee ene tee 28 Caliothrips woodworthi, bibliographic references...........-...------ Ue ase 44 Synomyimn or LeMennTipSs fasciatus ._..... 2... 22 cua 16 Seemed Diam of bean thrips. ...:2....---5..22-2--2-.-. 2.02.2 eee e ee 28 nmenepoarum miuralc, food plant of bean thrips....:.-.-:.-...-.--....------.- 31 Chrysomphalus aurantii, association with bean thrips on orange leaf......-..... 16 emmnemryorniica, enemy of bean thrips. ...........---.------------4-..6- 41 Cigarette flower, Chinese. (See Nicotiana glauca.) eee rood plant of bean-tbrips.-..--.-..\-....\..----.4------.-.--.- a Pemmenanpecarit Of bean thrips: .-......------2.-:-4-.:5---+---+---- 16, 17, 28-30 Crepsis (?) sp., food plant of bean thrips............ ee: oko aes 31 eenoas 10 control -of bean thrips..-.-.-.---.-°--.--/-+----------00 42-43 Setate-oll emulsion against bean thrips. .:.....-.-....----....-.----e200 43 @emimocyetis, probable food plant of bean thrips. ..............-.....--..... 31 mauaeran canadensis, food plant of bean thrips. .......---.--...---.-....-.-.. on mmuamee vrepypes, food plant of bean thrips. ..............-/2.--+----.--+--- 31 emrariad. 1000 plant of bean thrips..........---...--22-.-- 22-2 see ene 31 emtaecrares, Dibliopraphic reference. .......--2-esi..-22--- 2 eee ee ee eee 44 SRR N eH pen REMEREOMEIDG 2 ok 222 a sk oN oe Se heme 16 pyri. (See Thrips, pear.) teas Fish-oil soap. (See Soap, whale-oil.) Gnaphalium californicum, food plant of bean thrips.................2.2..--.. 31 femencnue annuus, food plant of bean thrips. ..............-.2.ecseeeenceeee 31 Heliothrips fasciatus. (See Thrips, bean.) Cth. POPU RUA a re eos cv sys,0\ ak = vic dw vin wine dv wae le ee a 9 PURCOUICPIOA, CANLCOL WY SDTV IDEs onesie a po ee wen cn en seen seasces 44 SEINE tree ck Sate falas p's Vaasa a s's ae ne oA 9 Heliotrope, wild. (See Heliotropium curassavicum.) Heliotropium curassavicum, food plant of bean thrips. ...............-.-..--- 31 Eiippodamia convergens, enemy of bean thrips..............-...-.-----+----4-- 42 Lacewing fly, green. (See Chrysopa californica.) Lactuca scariola. (See Lettuce, spiny wild.) mat EIanE OF OGM GAPING. Joc. dacn dc - d's oo ss vee connie debe ceaauncccs 28 pouty Wild, iood plant of bean thrips.......'..:...-5.0-.-.:--- 14, 21, 27, 30 47 48 THE BEAN THRIPS. Page. Lotus amerccanus, food plant of bean thrips: =). y...42- 5. Js 45eee eee 31 glaber, food plant’ of bean thrips... 2.22... -2-42. 1-2 di peat Mirabilis calyjorniea, food plant of bean thrips: 2.4 se Pe Ns 31 Nasturtium. (See Tropxolum major.) Nematode parasite, enemy of bean thrips._>.---2:._.4-.2.--.- 54 42 Nicotiana glauca, food plant of beam thrips. -_2..229... 0 0.-52- 2 31 Nicotine solutions, against bean thrips. 62.2). 2.05) .4 52220 0 = DG sulphate against bean thrips-.-22 4 22-222 2 ee Ge 16 Oil. (See Distillate oil and Soap, Whale-oil.) Orange, food plant of bean thrips--;- 22. .2-4-4c-) 2.3.2. 3l Chrysomphalus auranitt 2.2. --- 224.0) 236 16 medium in dispersion of bean thrips :2.2...-... 22.22 15 Parasite of bean thrips, artificial distribution”... _ =... 4 ..-- ee 44 Peach; food plant of bean thrips! 20 ee 2 ee ‘os oo 16, 31 Pea.,.food plant of bean thrips. . 24. a. 4.2 9-32 2s02 ee 14, 16, 28 wild. (See Lotus americanus.) Pear, food plant of beam thrips... 2 7.22 2228.22 16, 17, 28 Pine, food plant of bean thrips..i.. 2-5-1 2.2.-242.2-<.2¢- ee 16 Polygonum aviculare, food plant of bean ‘intae.. ieee eee ee 31 Poplar, tulip, bean thrips found thereom..--52-254-- 2-12 522 ee 31 Potato, food plant of hean thrips........-.. vew tyiinS Mielec Sol 28 Radish, food plant of beam thrips)... 2202 2. 252. ee eee ee al Rains in: control of bean. ‘thrips..2- 1.22222 22.2. . =a 5 2 eee 40-41 Soap, whale-oil, and blackleaf tobacco extract nex ins Heliothrips rubrocinctus and bean hes ee ey a Tees MR IE Be es 44 Sonchus oleraceus, food. plant of bean thrips. 25. 8) ose eae le ee au Sphzrophoria sulphuripes, enemy of beam thrips.+...-- 3.52244. -ase eee 41-42 Taesonia mellissimus, food plant of beam thrips. .2s-. 44. 42 a. 25-22 eee | 31 Thistle, sow. (See Sonchus oleraceus.) Thripoctenus russellt, artificial distribution -.2. 9.2.2 420 2s 44 parasite of beam thrips: :) 4.0) 22 4 oe 16, 41, 42 Thrips, bean, adult female; description. ..- 2-12-22...) 52.2) eee 9 habits. 5.0 550 see eso See er 17-23 male, deseription.23. 2 is5-.25. Jose 2 eee eee 10 adults, recently described, description.........-......--.-.-.-- ; 10 bibliography: 0. ce. Soels eee ae a ee - oe 44-45 control, artificially oc Bi Gt Le os oe a 42-44 pO? ALU 9 Da Rata aE, eR Hota aun idee 40-42 description... aides oe doe ae aot ie ee eee 8-9 distrilwiions 2357. 235 ee on Sara is Soh ayes eye ce se ee 14-16 ene, Gescriptioniacs.. «225 .aAsee od chee oe eee eee 10 hatehing 222d ha asa os aa oo ee eee ee er 23-25 stage, length.at Compton, Cal..4..22. 2395) -66 oc a eee 31-32 in Imperial Valley...t ce 2 a ee 37-38 enélities, natural.) 2. oysce et tee ees Ce Oe 41-42 feeding habits 22.3.0... 2G ue sos Poke oie cree eee ore oe aie eae 20-21 fight: ss Yex. pooled oh eee ee sk SL ee ee 21 food plants: 220) .20 oye aell - eaes Eee ee) ee 27-31 generations, numberj-at Compton, Cale: 247222 eee ee 37 habits of adtullt.3 ic... See cere ee te oe cia ee eee larvae eles. Hos hoe de Se oe ene eee eee 23-26 prepupa and: pupas esto. 2 Ease ee at eee ee 26-27 hatehing of eggs... Ug eves aad et Ae ee ee Oe ee (23-25 INDEX. 49 Page Thrips, bean, hibernation........- BE ae 4. OO eer ace vaheusieome at eatiom. ( ‘al 221, ie eee ae 36 entrance, 2c Compiony Calls a2. oy 2 3. eo. 36-37 ie mavelend: on Gramme jeune SS res ek 2 bse 15 EN Eo < ar ein ch Bb Oapue Soot eE « t ES he eae 16 imjury, nature and extent...........22--.- ES eae ae 8 geval, tirst-stage,-description:.....6..-.-02.-0%--- Boe Ch are 3 Be 10-11 ia ERTS ea a, Bek ae fe ce de 23-26 BRR R RS ek) Gin al en aa eee Sea ae ar CONT des. NE |) 25-26 second-stage, description.............- ses eta od Acorns I imevapertod, lencth at Compton; Cal.X..2252 F222... 5 ease. 32-34 aor bm er tall WV ANlew is vara te ele oe en Bs 38 Pg ie 9 fate Blass IS gis A Nap ee Rape A ns lee ee mR Pa 22 Smee Gyn WANLEr: oc. ol cm. t ak so Spec eee espe 22-23 MORMON. Soi ee agent Soa Aten ager UT a, 22 life cycle, total length ai Compton, Cal. ae Rot ce Se OR 36 Pensa! PN OOS rat 58 tts oY ena. SES Et he OS me wee ee es meine ot larva.....-..-.-.-- Lieto 2% Sect ee nea nymph, full grown. (See Maries. een pupa. “oh young. (See Thrips, bean, prepupa. ) RMCE CART GLO Pate ety cee es Soa oe Lely ete aoe 40 JISC Se ge ee oe Wate Renae At B8n Oke oes Boa ae 14-16 mancstinion, method and: time. \ 0 stse.02...205-..0..-..5-2. 18-19 number of eggs denote. Ba re. etn er ll ey period..... Uc cB goct sat a SRO and ea SAR My So 2A 19-20 peeps, on t : ; f 5 ell , ¥ ‘ ‘ i ‘“ 5 a ute ithe i a SL eS ere ° Wet : y ha ‘ f hk AR ee ar ca ae : Gre cs . an fi {i é w, biden nes a ao a 4 } PUN ¥ 1 Fi Dy f et Las b ay at ; > ; he f i Neat tat “ee? f : is Spee z ' . ys aay { 3 h ‘ a ‘ j LS i f et 2 : ‘ Thin . Oey raid , re 2 - } ' voy as : ‘ es f (7 t f i r - Pare ey of , “a 3 x ‘ r yA 2° ee 7 : a . - f ( 7 Pex. ) 1 ‘ x 1 - ) 7” \ ' ‘ ° } / my" 4 . { ‘ ) - \a \ , : q } \ 5 a : : ‘ 4 re ‘a - Den ry . j RB opr pte a, ui A. BURGESS, a i » - : ma td Expert in Charge of Biological Investigations, ye \ eS } Issvep Fesruary 11, 1913, - | | Ly) 3 4, 4 ? ¢ ey ‘ : \ A | M4 I Sf } 2 d \ LS, ’ WASHINGTON: GOVERNMENT PRINTING OFFIOE, 2 1918, f play ebay i wes i oy ay xP’ U. S. DEPARTMENT OF AGRICULTURE, ~ BUREAU OF ENTOMOLOGY—BULLETIN No. 119. L. O. HOWARD, Entomologist and Chief of Bureau. THE DISPERSION OF THE £GIPSY MOTH. BY A. F. BURGESS, EHepert in Charge of Biological Investigations, Issurp Frspruary 11, 1913. | Y = Dp . Denil an i} ? tN Mic rant > marty nN WASHINGTON: GOVERNMENT PRINTING OFFIOE, 1913, BUREAU OF ENTOMOLOGY. L. O. Howarp, Entomologist and Chief of Bureau. C. L. Marguatr, Entomologist and Acting Chief in Absence of Chief. R. 8S. Cuiirton, Hxecutive Assistant. ' W. FE. Tastet, Chief Clerk. FE. H. CHITTENDEN, in charge of truck crop and stored product insect investigations. A. D. HoPKINs, in charge of forest insect investigations. W. D. HUNTER, in charge of southern field crop insect investigations. FE. M. WEBSTER, in charge of cereal and forage insect investigations. A. L. QUAINTANCE, in charge of deciduous fruit insect investigations. EK. F. PHILLIPS, in charge of bee culture. Rouia P. CurRRIE, in charge of editorial work. MABEL COLCORD, in charge of library. PREVENTING SPREAD OF MOTHS. LABORATORY. (At Melrose Highlands, Mass.) A. F. Burcsss, in charge of biological investigations. W. F. FISKE, in charge of parasite and disease investigations. KENNETH W. Brown, C. W. CoLuins, J. J. CULVER, JOHN EK. DUDLEY, Jr., HarTLey R. Goocu, CHas. W. Minott, F. H. MOSHER, HARrotp A. PRESTON, EK. A. Proctor, JOHN V. SCHAFFNER, Jr., M. B. SHEPHERD, C. W. STOCKWELL, J. N. SUMMERS, W. B. TURNER, REGINALD WOOLDRIDGE, assistants. FIELD WORK. D. M. Rocers, in charge of Eastern territory. L. H. WortTuHLEY, in charge of Western territory. Harorp A. Ames, I. L. BatLey, Henry N. Bean, FRaANK W. Graves, Jr., H. L. McIntyre, D. G. MurPHy, CHARLES E. ToTMAN, H. W. VINTON, assistants. >) a! y LETTER OF TRANSMITTAL. U. 8. DeparTMENT oF AGRICULTURE, Bureau or EntTomowey, Washington, D. C., July 24, 1912. Sm: I have the honor to transmit the manuscript of a paper en- titled “The Dispersion of the Gipsy Moth,” which is a result of extensive studies made to determine the means by which this insect is spread. The gipsy moth has caused enormous injury to the horti- cultural, forestry, and shade-tree interests in the New England States, and the results of the investigations made have an important bearing on the proper methods of restricting the further spread of this serious pest. I recommend the publication of this manuscript as Bulletin No. 119 of this bureau. Respectfully, L. O. Howarp, Entomologist and Chief of Bureau. Hon. James WItson, Secretary of Agriculture. Introduction...... CONTENTS Cnn INSeCts are Spread... 0.0... obec yes ae we eect ees Investigations of the dispersion of the gipsy moth.....................-....-- IRE I ICICU. oe ooo np nie wie a es ae Lin yee wee ended ae skp st Mememeerain work resumed......................---.--- eh naline Five So MRR BN The automobile as a means of dispersing the gipsy moth................-....- Sewer iieans 01 dispersing the gipsy moth.........-.........-22.---2----2---- Relation of birds to the dispersion of the gipsy moth....................-.-.-- Continued dispersion of the species unexplained.................-...-.....-- Suggestions concerning the spread of larve by the wind. ...................- REPEC IOWODK 2.2. 2. ee enn eee ee eee ee ee hg eee Summed Pancoin, Mass. ......2..-<---.----+-0--2-.5ecese ene ceee Smemiiments im Iynn Woods, Mass...........--.....--2-2.---.04--s eee Meemmmmemigiat Olitondale) Mass. ......-.---+2----22-.22- eet eee eee ec dee ements on bynn Marshes; Mass_...--.....2---.------.f.-4--5+-+-0% Quantity of silk produced by first-stage gipsy-moth larve....................- aero o1temperature to hatching of eggs........---------- 2-2-2 eee ee eee meee tem perature on activity of larve...........-...2-.-.2....2+-20.--- NMEA MCTUMNCIU S25 6 252. = has 2s ee ee ele ee ete ee sae at er 2 a ee reo aati Les Sie minnny= x = Ae = ps Sinn wee ner aenvity to the spinning of silk..:........,---:--+-----+----s--+- Secaitons where ere clusters are deposited.....-..........-.2.---2.-----20-- menace larva: Can Crawl......2...¢--.-..-c--02------- eee sedeeeee ENR eyed. alae ee as Shen Pe 2c wn eae I ct 2 ae, So ee Sls SER ars DP eRe ee One fe oan eee Seeeemrror cod DIANtS..........-..5-222---5-- sees fn Sg ae eee CR uence velocity Of the Wind... ..... 2222.22 ees ee nce ee General summary. rs IR tee Se a 2 a ee tay es acs wh eae oe be oe Relation of scouting records to wind dispersion................-...-22----00- Records of dispersion of the gipsy moth secured from reports of scouting in EEG sos oe ea oe te eso oe 2 ee Seo «eee we eke eae eek Me Records of dispersion secured from several selected towns.............-..-.--- Senne WOOUlANO AFCAS. 2.2.0... cece ce nee te ewaceees enn 1at Lisbon, Meso.) ic. ne eee ge elie ee eee cee mainte I Yarmouth, Me-:..... 2... 2222s cee cece teen ecb dens Record of scouting in Milton, N. H....... ee Ee ot Rea ye tN ree. Dats IES 888. TOGO NS Ady Rete chon Sele Sond wh seg ALN es Wau eee See er ecouting in Dennineton, N-H-........2.. 6.2.2 eee Meeerd of scouting in Gardner, Mass:..........)-.-.--2----c-ccacecceecwecees ircinie’ ot Creating Mand. o.oo. . oe oc oe Deke de ee nn meQgvine- ir Warenam, Mass... ..5.-. 05 ss eke oe eee een bene doneeee NIECE SCOIIGITIS WOOCIRTHWOTCOR, c0 5 ss dpe a2 a 6k sous cna ws dec ean cen en cece Effect of wind spread on the problem of gipsy-moth control.................-- Summary...:.... Recommendations 53 55 56 58 [ILLUS TRATIONS. PLATES. Puate I. Gipsy-moth egg clusters’ on charred wood on the edge of a stream, Saugus, Mass., May, W912. 3.02 2 ee II. Female gipsy moths depositing eggs on oak foliage, Melrose, Mass. . III. Lumber pilesat York, Me.; gipsy-moth egg clusters on upturned board at right of foreground ..5...0... 2-225 24ers IV. Crow’s nest in top of pine tree: ..i-......<-....-s:-see Pepe so 2S VY. Gipsy-moth caterpillar, showing aerostatic hairs. Fig. 1.—First-— VI. Trap moored in pond to test aviation of gipsy-moth larvee..... Petey: VII. Trap built on top of observation tower to test aviation of gipsy-moth VIII. Screens treated with tanglefoot attached to water tower to test avia- tion of gipsy-moth laryee. 25s 22 sco... soe see oe eee IX. View of salt marshes near Lynn, Mass., where experiments on aviation of caterpillars were conducted; post and box used in experiments. X. Portable screens used for caterpillar-aviation experiments.......... XI. Fig. 1—Female gipsy moths depositing egg clusters on white-oak tree near the ground. Fig. 2.—Egg clusters on stone wall ...-..... XII. Oak tree showing gipsy-moth caterpillars spinning to the ground.... XIII. Solid white-pine block near Nashua, N. H.......................-- XIV. Row of large maple nursery stock infested by the gipsy moth........ XV. Gipsy-moth egg cluster on small Norway spruce tree in nursery row. XVI. Weeping mulberry showing bird’s nest and near by two gipsy-moth Fig. 1. 2. 3. Map l. ego clusters... . ac. ~ 2o Re ce TEXT FIGURES. Diagram showing maximum and minimum temperature before and after hatching of eggs of the gipsy moth, 1908-1911................. Female pupal case and egg clusters of gipsy moth on stone foundation under woodwork of hotise;...<.3. o.oo bo se eee eee é Diagram showing the proportion of time the wind blew in each direction, when wind spread was possible, during April and May, 1902-1911. . . Map showing location of towns and cities in New Hampshire and Massa- chusetts where scouting records have been consulted to compare the relation of infestation to, wind spread >. 2... 322 n222..- Baceae cee . Map of town of Boylston, Mass., showing increase in gipsy-moth-infested localities, 1909=10:and 1910=11s.2~. 22 Saas S353 ea eee eee . Map showing towns and cities in New England where woodland scout- ine was done, 1911-1275 a2 eee eee oe eee ee MAP. Showing dispersion and present distribution of the gipsy moth in New Eingland «25.05. 1 22+ svc asics Sate aes nes Biel wee ie eee 6 40 THE DISPERSION OF THE GIPSY MOTH. INTRODUCTION. _ The dispersion of any insect that has been introduced, accidentally or otherwise, into a new country offers an interesting opportunity to study the elements which aid in bringing about its transmission from point to point within that country, and this is particularly true con- cerning one of so great economic importance as is the gipsy moth. When the first work to suppress this insect was taken up in the early nineties an attempt was made to determine all the means by which the insect was spread, and since that time any data bearing on the spread of the pest have been eagerly sought and carefully studied in the hope that better methods could be found for its control. The region surrounding Medford, Mass., where the gipsy moth was in- troduced in 1869, is the center of one of the most thickly populated sections of the United States; hence there was an unusual oppor- tunity for the spread of the insect by artificial means. In spite of the work that has been done and the observations that have been recorded it has remained until the last two years for a demonstra- tion to be made of the manner by which this insect is spread, to the greatest extent, by natural means. MEANS BY WHICH INSECTS ARE SPREAD. One of the principal methods of insect locomotion and of spread- ing is by flying, and there is little chance of preventing the spread of a strong-flying introduced species which has become thoroughly established. The continued spread of the elm leaf-beetle and of the brown-tail moth illustrates how flying insects are dispersed. There is, however, another class of insects which does not spread by flying. Several distinct types exist, and among them may be mentioned such insects as the San Jose scale and other closely re- lated species. The structure of the females of this group is such that they remain fixed before becoming sexually mature; hence the distribution of the species is confined, so far as natural means is concerned, to the dissemination of the young, which have the ability to move about for a limited period. The adult insects are spread by artificial means on nursery stock and on living trees or shrubs that are shipped from one locality to another for planting or propagation. The brown-tail moth has also been distributed on nursery stock, but it is carried in this way while the small caterpillars are in the hibernating webs where they pass the winter. fig 8 THE DISPERSION OF THE GIPSY MOTH. While the gipsy moth does not belong to the same class as the scale insects just mentioned, it resembles them inasmuch as it is not spread by the flying of the adult, for although the females are pro- vided with wings, they are unable to fly, owing to the extreme weight of the body. Dispersion, therefore, is greatly restricted in this stage of the existence of the insect, and this is important, as it bears directly on the control of the species. INVESTIGATIONS OF THE DISPERSION OF THE GIPSY MOTH. Investigations which were carried on during the early nineties have been fully treated in the report on the gipsy moth by For- bush and Fernald, published by the Massachusetts State Board of Agriculture in 1896, natural and artificial dispersion being con- sidered on pages 94-116. Although it appeared at that time that excellent opportunities were afforded for studying the dispersion of this insect, still it must be remembered that the pest was abundant in relatively few localities during the years covered by that report, especially when the conditions existing in later years are considered in comparison. It is evident that the extent of distribution of any insect depends largely upon the abundance of the species, and if large areas are badly infested migration is often necessary in order that many of the individuals may secure sufficient food. The dispersion of the species, as treated in the above mentioned report, was considered as local and long distance. The former condition was brought about by egg clusters being broken and scattered by birds or other animals that frequent infested trees. Clusters were also carried on driftwood (see Pl. I), and those deposited on leaves (see Pl. II) were sometimes distributed by the wind. The caterpillars were occasionally found clinging to the bodies of animals or to the clothing of persons who had visited infested places and were carried short distances in this way. Many colonies were established in remote districts by the carriage of the larve on vehicles, and egg clusters were sometimes transported on cordwood or lumber products shipped from infested forests. (See Pl. III.) The distribution of caterpillars upon vehicles was con- sidered so important when the gipsy-moth work was begun in 1891 that inspectors were stationed along the main highways to stop and examine all vehicles and to destroy any caterpillars found before allowing them to pass out of the infested area. This precaution was entirely warranted in view of the discovery that many farms had become infested by the transportation of caterpillars on vehicles. Places infested in this manner, however, were usually occupied by milkmen, peddlers, swill gatherers, or persons whose business caused them to drive regularly to and from the city during the summer, or to neighborhoods that were badly infested with the gipsy moth. Bul. 119, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE I. MOTH EGG CLUSTERS ON CHARRED WOOD ON THE EDGE OF A STREAM, SAUGUS, MAss., MAY, 1912. GIPSY inal.) o o i (Or spersed on driftwood. i smay be d is specie Showing how th Bul. 119, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE II. FEMALE GIPSY MOTHS DEPOSITING EGGS ON OAK FOLIAGE, MELROSE, MASs. Arrows point to pup, moths, and egg clusiers. (Original.) PLATE III. Bul. 119, Bureau of Entomology, U. S. Dept. of Agriculture. ( SONIHOLIH WOY-) “GNNOYDSHOY JO LHOIY LV GUvVOgG GANYNId~f) NO SY3LSNID DOF HLOW|-ASdID {a ‘MYOA LY S3TIg Y3aaWn7 CONTROL WORK ABANDONED. 9 The efficient work which was carried on by the Massachusetts State Board of Agriculture during the early nineties rendered the con- tinuance of vehicle inspection unnecessary, as the moth had been greatly reduced in numbers and very few badly infested localities could be found. At the time the work was abandoned in 1900, 34 towns and cities surrounding Boston were slightly infested. A few isolated colonies were present outside of the limits of this area, but in most cases these had been reduced almost to the point of ex- termination, and in several colonies none of the insects had been found for two or more years, in spite of the fact that careful examina- tions were made annually. It should be said that very little if any of the territory in the infested area was what would be considered now as badly infested, and owing to the thorough manner in which the work was prosecuted the danger of spread was reduced to a minimum. CONTROL WORK ABANDONED. In the winter of 1900 suppression measures were abandoned by the State of Massachusetts, but during the next five years considerable individual effort was expended to protect the trees in the residential sections, particularly by owners. The infestation became so serious, however, in the summer of 1904, and the depredations of this insect were so severe, owing to its remarkable increase in numbers, that action was taken by the State in the spring of 1905, and money pro- vided for the purpose of affording relief and preventing the destruc- tion of trees in towns and.cities as well as of attempting to control the moth throughout the infested area. The State force was organized by Supt. A. H. Kirkland, and con- ditions in the territory, which was the central part of that which was infested when the work was stopped, are well described by the follow- ing extract from his first annual report.' As would have been expected, during the year 1900 and 1901 but little notable damage was caused by the gipsy moth, although evidence was not wanting to the trained observer that it was rapidly multiplying in woodlands and on neglected private estates. It was apparent that nonresident property owners _particularly paid practically no attention to the increase of the insect and that farmers and others owning infested woodland areas were unwilling, because of the expense, to fight the insect. In 1902 numerous estates were severely injured throughout the central district, while woodland colonies of some magnitude had developed from which the insects were swarming in all directions. The summer of 1903 showed that the moth had established itself again in alarming numbers in various parts of the infested district. Serious colonies had developed in the woods of Arlington, Medford, Saugus, and Malden, and the Lynn Woods colonies had assumed notable proportions. In 1904 it was apparent to all that the gipsy moth had developed to a remarkable extent, reinfested the areas from which it had been cleared, and even extended its bounds into previously noninfested 1 First Annual Report of the Superintendent for Suppressing the Gipsy and Brown- Tail Moths, 1906, p. 12. 10 THE DISPERSION OF THE GIPSY MOTH. territory. The caterpillar outbreak was sufficient to convince every tree lover of the necessity of concerted action against the moths. While in many places in the afflicted district the trees under the charge of municipal authorities were cared for with considerable success, private estates and woodlands in June and July presented shocking scenes of devastation. In many places the work of fire could not have been more thorough or alarming. From Belmont to Saugus and Lynn a continuous chain of woodland colonies presented a sight at once disgusting and pitiful. The hungry caterpillars of both species of moths swarmed everywhere; they dropped on persons, carriages, cars, and automobiles, and were thus widely scattered. They invaded houses, swarmed into living and sleeping rooms, and even made homes uninhabitable. GIPSY-MOTH WORK RESUMED. It must be noted that the conditions above described were most favorable for the dispersion of this insect, and in order to determine so far as possible the territory which had become infested, inspectors irom the office of the superintendent made an examination of a large area outside of that known to be infested when the work was stopped. Of necessity this examination was hurriedly done, owing to the fact that a sufficient number of trained men could not be secured in the limited time available, and also because a large number of the more experienced workers had to be employed in fighting the intolerable conditions in the central towns. The results of the scouting work, however, showed that the gipsy moth was present in 124 towns and cities in Massachusetts. Seven infested towns were also found in New Hampshire, extending from the Massachusetts line along the sea- coast to and including Portsmouth, so that the entire infested area proved to be six times greater than when the work was abandoned. Each year since 1905 more or less scouting work has been done by the State of Massachusetts in the towns outside of the known infested area, and in Maine, New Hampshire, Rhode Island, and Connecticut large sections have been examined by scouts working under the direction of Mr. D. M. Rogers, superintendent of moth work for the Bureau of Entomology, United States Department of Agriculture, and every year additional infested territory has been found. As a rule very few egg clusters are found in the outside towns, but it should be stated that the examination is confined to the roadsides, residential sections, and orchards, it being impossible to examine all the large forest areas involved. The same factors which previously resulted in the dispersion of the insect were found to be operating, but the danger had been greatly increased owing to the development of many high-speed and long-distance trolley lines which conveyed people from the cen- ters of population to the rural districts rapidly and in many cases without changing cars. These increased transportation facilities afforded an excellent opportunity for the distribution of gipsy-moth OTHER MEANS OF DISPERSING THE GIPSY MOTH. ti caterpillars, and the presence of the insect in woodland surrounding lakes and ponds which were frequented by camping parties was the natural result. During midsummer, when caterpillars were abun- dant, they could frequently be seen crawling on the clothing of people on electric cars and sometimes have been observed on the seats and running boards. In this way they are often carried consid- erable distances. THE AUTOMOBILE AS A MEANS OF DISPERSING THE GIPSY MOTH. Perhaps no single form of transportation has caused so wide a dispersion of this insect as the automobile. When the gipsy moth was most abundant during the nineties it was seldom possible for caterpillars to be conveyed on teams or wagons more than 20 miles in a single day, but with the advent of the automobile this danger was greatly increased. In fact, since this mode of travel has be- come popular the traffic between the cities in eastern Massachusetts and the seashore and mountain regions in Maine, New Hampshire, and Vermont has increased remarkably, and the spread of the insect has been proportionately greater. The lines of automobile travel are usually along trunk roads, many of which are bordered by badly infested woodland. These condi- tions afford an excellent opportunity for the young caterpillars to spin down from the trees and to be carried away by any moving object with which they come in contact. Cases are on record where city residents who own country or seashore places have caused them to become infested by journeying back and forth by automobile. So many cases of this kind have been found that it is now considered one of the easiest means by which the insect is spread. Automobile traffic is very heavy in June, when the gipsy moth is most likely to be carried in the caterpillar stage. OTHER MEANS OF DISPERSING THE GIPSY MOTH. Another means by which the gipsy moth is dispersed to outlying regions is through the unintentional carriage of caterpillars or egg clusters by visitors or travelers. In 1906 this insect was found in small numbers on the grounds of the National Soldiers’ Home at Togus, Me. The nearest known infestation at that time was 81 miles away, and, from the condition of the infestation and the circum- stances connected with it, it seemed probable that the insect had been brought there either in the egg or caterpillar stage on the clothing or among the effects of some of the inmates or visitors who came from the infested area in Massachusetts. Isolated infestations are continually being found in towns some distance from the infested area, especially on farms or in camps where parties from Boston and vicinity spend their summer vacations. 12 THE DISPERSION OF THE GIPSY MOTH. In the fall of 1910 a flourishing gipsy-moth colony was found on a farm at Charlton, Mass. The worst part of the infestation was in a small orchard near the farmhouse and in a row of trees some dis- tance away which bordered on cultivated land. Inquiry showed that for a number of years it had been the custom for the owners of this farm to take children from Boston and vicinity for summer boarders. The vacation of each boarder usually lasted about two weeks, so that they were continually changing, and there is no doubt that gipsy- moth caterpillars or egg masses were brought from the infested regions in the baggage of the visitors. Many similar cases might be cited, but this will suffice to illustrate the ease with which this insect may be carried long distances. In December, 1909, a flourishing colony of the gipsy moth was found in the residential section of Wallingford, Conn. This is more than 100 miles from the nearest badly infested area. Examination showed that the worst infested trees were in the business section, and many of them were in the rear of a grocery and provision store. Supplies of vegetables, such as early lettuce, cucumbers, and toma- toes, had been received in season by this store from market gardens located near Boston, and there seems to be little doubt that egg clusters of the gipsy moth had been transported inadvertently on the boxes or in the packing material. RELATION OF BIRDS TO THE DISPERSION OF THE GIPSY MOTH. During the past few years the scouting operations in Massachusetts and New Hampshire have resulted in the discovery of gipsy-moth colonies in regions inaccessible to travel, and often in places which would seldom, if ever, be frequented by man. This condition of affairs has occurred so often, and an explanation for the presence of these colonies became so difficult, that it seemed desirable to take up the subject in a more thorough-going manner for the purpose of determining whether the insect might be distributed by some other means. In some of these cases it is possible that the colonies might have started from caterpillars that had been dropped by birds, but the distances between many of them and known infested regions were so great as to render this theory in most cases highly improb- able. Furthermore, when caterpillars are picked up by birds they are usually injured to a greater or less extent, and the chances of their developing so that vigorous colonies would result in a few years are very remote. Another factor in relation to the influence of birds on the spread of the gipsy moth, and one which has received much serious consideration, is the possibility of their feeding upon the eggs of the species and distributing them in the excrement. If fertile eggs of the gipsy moth should be eaten and pass through the alimentary canal of some of our insectivorous birds without sustain- - RELATION OF BIRDS TO DISPERSION. 13 ing injury, it would undoubtedly offer a valid explanation of the cause for some of the outlying colonies which have been found. In the report of Forbush and Fernald, already cited, detailed accounts are given of the part played by practically all the insectivorous birds which are at all common in eastern Massachusetts. At the time the observations were made a large number of trained field observers were constantly employed, and few, if any, of these re- ported that birds were found feeding upon eggs of the gipsy moth. In fact, the report states that the only bird that has been found feeding upon these eggs in the field is the English sparrow, and, as it is normally a grain-feeding species and one that frequents cities or centers of population, it is doubtful whether the moth would be dis- persed to any great extent if it were possible for the eggs to pass through the bird without injury. Fortunately, during the winter of 1909-10 two sets of experi- ments were conducted for the purpose of determining whether gipsy- moth eggs would pass through the alimentary canal of birds without injury. These tests were made independently, and in both cases it was necessary to disguise the eggs in other food or force the birds to feed upen them. One set of experiments was begun in February, 1910, by Mr. C. W. Collins, of the parasite laboratory of the Bureau of Entomology. He used a number of English sparrows and a single pigeon. The sparrows were fed by placing gipsy-moth eggs in their mouths and requiring them to take a swallow of water to wash them down. Of 356 eggs fed in this way 142 were found intact in the excrement and the balance were broken during the process of digestion or re- mained in the gizzard. Only seven eggs hatched, which shows that under this artificial treatment the chances for survival of the eggs are very small. None of the eggs fed to the pigeon hatched after being voided. These experiments indicate the extreme improbability of either of these birds selecting gipsy-moth eggs for food, and the chances of the insect being disseminated in this way appear very slight, both on account of the injury to the eggs in passing through the bird and because the distances of migration of the species are relatively small. The other set of experiments was conducted by Mr. Wm. Rieff,? of the Bussey Institution, Harvard University, during March of the same year. As no native birds were available for the tests the follow- ing species were used: German canary bird, English yellow-hammer, English chaffinch, Japanese robin, screech owl, and carrier pigeon. The eggs were disguised in food, such as bread crumbs. In the case 1 Some Results from Feeding Eggs of Porthetria dispar to Birds. Journal of Economic Entomology, vol. 5, no. 4, Aug., 1910, p. 343. *Some Experiments on the Resistance of Gypsy Moth Eggs to the Digestive Fluids of Birds, Psyche, vol. 17, No. 4, Aug. 1910, p. 161. 14 THE DISPERSION OF THE GIPSY MOTH. of the Japanese robin they were placed inside the larve of the meal beetle (Tenebrio molitor), while those fed to the screech owl were inserted in a freshly killed mouse. Of 52 eggs that passed through the Japanese robin three hatched, while of 112 eggs vomited by the screech owl with the remains of the mouse seven hatched. No hatching resulted in the Yeu with the other birds. The writer says: To sum up the details of these various experiments it is seen that gipsy- moth eggs can withstand the action of the digestive fluids of birds belonging to at least two families, Turdidse and Bubonide, without suffering any, or only slight injury. In regard to the large family, Fringillide, also an insec- livorous group, I am inclined to believe that these birds might also occasionally distribute gipsy-moth eggs in spite of the negative results obtained in my experiments. : These conclusions seem too sweeping because of the large per- centage of the eggs that failed to hatch, and when the conditions under which the birds were fed is considered it is doubtful whether comparable results would be secured under natural conditions, The Bubonide and Fringillide are not, for the most part, in- sectivorous birds, and it is doubtful if the latter would, except in rare instances, eat eggs without crushing them or at least attempting to break away their outer covering, as this is their usual habit when feeding dn seeds, which are their natural food. Whether eggs would pass through the alimentary canal of some of vur less domesticated insectivorous birds unharmed is an open ques- tion, and one very difficult to settle, owing to the fact that these wild species can not be experimented with in confinement in any satis- factory way. It should also be noted that the digestive process in birds is more rapid under natural conditions than when they are confined for experimental purposes; hence it may be that in nature a larger percentage of eggs would withstand the digestive action, but the distance that they could be carried would be correspondingly reduced. The main question, however, appears to be whether birds actually eat eggs of the gipsy moth in the field. Men engaged in the moth work frequently find egg clusters which have been broken, and sometimes in such a condition that one might conclude that they had been pecked at by birds. Clusters are sometimes broken by squirrels or other animals, and not infrequently this is charged up to birds. Mr. John A. Farley, one of the agents of the Massachusetts State forester’s office, reports the following ob- servation, which shows how carefully matters of this nature must be investigated in order to prevent error. On visiting a wooded area where it had been reported that birds were feeding on gipsy- moth eggs and where the clusters showed every indication that this CONTINUED DISPERSION OF THE SPECIES UNEXPLAINED. 15 eonclusion was correct, he found that the chickadees (Penthestes atricapillus) were working among the clusters and were apparently ‘feeding. On making a more thorough examination he found that a few small white-pine seeds had been stored away in the cavities that were made by the birds in the gipsy-moth egg clusters. No egg- shells or other evidences of feeding were found, and later Mr. Farley saw the birds depositing the seeds. Later in the season an examina- tion was made and the seeds previously secreted were missing. Dis- sections have shown that pine seeds are a favorite food of this species and that they are often collected and stored for a winter food supply. The reliability of these data is unquestioned and throws an. interest- ing light on the subject. It has been suggested by Mr. William Brewster, the well-known ornithologist of Concord, Mass., that the gipsy moth may be spread in the egg stage by crows, hawks, and other large birds that make nests (Pl. IV) of large twigs, as it would be possible for them to carry material which was infested with egg clusters. This may happen in some cases, but it seems probable that it would result in local rather than long-distance dispersion. In view of the results secured by the experiments above mentioned and of the observations cited it seems that the evidence is wholly inadequate to prove that birds were responsible for distributing the gipsy moth to the large area which was annually becoming infested. Furthermore, towns where only one small infestation was found might, the following year, be infested in 20 or 30 different locali- ties, all of which were remote from influences which would favor artificial means of spread. As the first infestation found in a town is usually small and is thoroughly treated, no reasonable explanation could be given for the presence of so many colonies the following year. The fact, also, that many of these outbreaks were located in places that were seldom frequented by men or animals indicated strongly that. some other natural means must assist the insect in becoming generally dispersed. CONTINUED DISPERSION OF THE SPECIES UNEXPLAINED. For several years this matter was thoroughly considered by the officials connected with the gipsy-moth work, but it seemed impossible to come to any conclusion as to the means whereby so many small isolated colonies had become established. The theory was advanced that occasionally one of the female moths, developed in a badly infested colony where the adults were abnormally small on account of an insufficient food supply for the larvae, might be able to fly, and in this way cause the dissemination of the pest. No facts to prove this theory have ever been secured, and although this might happen occasionally it wholly fails to explain the reason for numerous small 16 THE DISPERSION OF THE GIPSY MOTH. colonies which are found long distances from any badly infested area. Isolated colonies have been usually so far away from infestations that it would have been practically impossible for small females to have* covered the distance by flying. SUGGESTIONS CONCERNING THE SPREAD OF LARVA BY THE WIND. In the fall of' 1909 Prof. E. D. Sanderson, who was then ento- mologist to the New Hampshire Agricultural Experiment Station, and who was deeply interested in the work of suppressing the gipsy moth, suggested that the caterpillars of this insect might be car- ried by natural means, and later he wrote to Dr. L. O. Howard, Chief of the Bureau of Entomology, calling attention to an article in the Standard Natural History relative to the peculiar hairs on the young caterpillars and suggesting that they might assist the larvee in being carried by the wind. An examination of the lter- ature showed that the matter had been mentioned by Forbush and Fernald in 1896 and that the hairs had been described by Wachtl and Kornauth in a publication relating to experiments in the forests of Austria in 1893. This paper deals principally with hairs of peculiar structure which are found in the first-stage larve of the nun moth (Psilura monacha L.) and states that similar hairs are . found on the first-stage larvee of Porthetria dispar. These hairs are not present on the caterpillars in the later stages, and as they are provided near the base with a globular enlargement, which the authors believed to be filled with air or gas, they were ~ called aerostatic hairs and the globes aerophores. They state that the first-stage nun larve are carried long distances by the wind, and one might assume that the same is true of the gipsy-moth larve, as they are provided with similar hairs. A microscopic examination of one of these first-stage caterpillars shows that two kinds of hairs arise from the tubercles which are arranged in rows on the body. Only a few slender acuminate hairs, some of which are nearly half as long as the caterpillar, arise from each tubercle (Pl. V), but many short hairs are present which have a small globular swelling near the base. Whether these aerophores actually aid in making the caterpillars more buoyant, as is sug- gested by the authors above mentioned, is not positively known, but it was of great importance to know whether dispersion is actually brought about by means of the small larve drifting in the wind. EXPERIMENTAL WORK. In the spring of 1910 a preliminary experiment was tried in the laboratory by releasing caterpillars, which had been encouraged to spin as much silk as possible, in front of an electric fan. Although PLATE IV. Bul, 119, Bureau of Entomology, U. S. Dept. of Agriculture. s Crow’s NEST IN TOP OF PINE TREE, POSITION INDICATED BY ARROW. ntly found in or around such ginal.) clusters are freque Gipsy-moth egg (Ori nests, Bul. 119, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE V. Fic. 1.—FIRST-STAGE LARVA, SHOWING THE TWO KINDS OF HAIRS. ENLARGED. (ORIGINAL. ) Fic. 2.—a, TUBERCLE FROM FIRST-STAGE LARVA, SHOWING Hairs; 6, AEROSTATIC HAIR; c, ACUMINATE HAIR. a, Much enlarged; b, c, more enlarged. (Original.) GIPSY-MOTH CATERPILLAR SHOWING AEROSTATIC HAIRS. PLATE VI. Bul. 119, Bureau of Entomology, U. S. Dept. of Agriculture. (IVNIDINO) PVAYV] HLO|II-ASdI5} JO NOILVIAY LSS] OL GNOd NI GSYOO|| dvuL EXPERIMENTS AT LINCOLN, MASS. 17 it was very difficult to determine how far they might be carried under such conditions, owing to the small size of the rooms where the experiment was tried, it was possible in a few cases to secure specimens which had drifted from 20 to 30 feet from the fan. This led to an attempt to test the matter under outdoor conditions. Arrangements were made with Mr. L. H. Worthley, then assistant forester of Massachusetts, whereby the tests would be made coopera- tively with the department which he represented. Supples and assistance were furnished by the State, and several men employed by the Bureau of Entomology attended to certain parts of the work. Many valuable suggestions were secured from Mr. Worthley, and from Messrs. D. M. Rogers and W. F. Fiske of this bureau. In carry- ing on the tests especial credit is due to Mr. C. W. Collins, who assisted in many of the experiments; to Messrs EK. A. Proctor, J. V. Schaffner, and K. W. Brown for assistance and suggestions; to Mr. H. R. Gooch, who constructed the screens and apparatus used; to Messrs. C. W. Stockwell, F. H. Mosher, and John E. Dudley, jr., for helpful suggestions and for recording data on several phases of the work; and to Messrs. H. S. Barber, Melvin Guptill, H. A. Preston, and W. N. Dovener, who prepared the photographs and accompany- ing illustrations. Suggestions which had a practical bearing upon the tests were made by those mentioned and by many others con- nected with the work at the parasite laboratory, so that all have contributed to the results which will be given. For the weather conditions in Massachusetts we are indebted to Mr. J. W. Smith, district forecaster of the Weather Bureau, United States Department of Agriculture, at the Boston office. Data have also been secured from local forecaster Edward P. Jones, at Portland, Me., and from local forecaster E. C. Vose, at Concord, N. H., who have very courteously allowed the records of their offices to be freely used. Plans were made to carry on several experiments out of doors as soon as the caterpillars began to hatch, and for this purpose a num- ber of favorably situated localities were selected. In each case a sereen of galvanized-iron wire was attached to a wooden frame, and after the netting had been treated with a thin application of tree tanglefoot it was set up so that caterpillars were likely to drift upon it if carried by the prevailing wind. EXPERIMENTS AT LINCOLN, MASS. The first trap was placed on a raft (Pl. VI) which was moored near the center of Sandy Pond, Lincoln, Mass. ‘Two screens, each 12 feet long and 6 feet high, were placed at right angles so as to form a cross. The screen used was ordinary poultry wire having a mesh about 1 inch in diameter. The woodland surrounding this pond was 60474° Bull. 119—13——2 18 THE DISPERSION OF THE GIPSY MOTH. moderately to badly infested with the gipsy moth, and it was ex- pected that if the young caterpillars were carried by air currents it would be possible to secure some of them in the tanglefoot which was applied to the wire netting. The pond is about a mile and a half — long and three-fourths of a mile wide. As there are two small islands on which brush and sprouts were growing near the west side, ~ an attempt was made to anchor the raft as nearly as possible at a point midway between the islands and the opposite shore. The raft was constructed April 25, 1910, and an attempt was then made to — anchor it in the center of the pond. Owing to the high wind it was found impossible to do so, therefore it was anchored near one of the small islands, where it remained until May 2, when the anchorage was changed to the center of the pond. On this date the screens were examined, but no larve were found in the tanglefoot. On May 9 the pond was visited, and it was found that the raft had drifted from its anchorage to the shore at the northeastern end of the pond.- Infested woodland was present within 200 yards of where the raft lodged. The tanglefoot was examined, but no cater- pillars were found. Owing to the strong wind it was impossible to tow the raft to the center of the pond, so it was allowed to remain where it was found. On June 9 a visit was made to this trap for the purpose of making the final examination and dismantling it. A single caterpillar was found in the tanglefoot, which proved upon a careful examination to be a first-stage gipsy-moth larva. Owing to the difficulty of thor- oughly examining the wire screen, because some of the tangle- foot had become rather hard and also because of the presence of an innumerable number of Micro-Diptera and other small insects, the screen was taken from the wooden form and brought to the laboratory, where later in the season it was cut up into small strips and thoroughly examined. This work was done by Mr. J. V. Schaff- ner and Mr. Emery Proctor, but no other gipsy-moth caterpillars were found upon it. During the first part of the experiment the weather was cool, which probably resulted in the young larve mov- ing about but little, and this may explain why more caterpillars were not caught in the trap. Attention should be called to the small area of screen which was exposed, and in the hight of future experi- ments it dces not appear strange that no more caterpillars were secured. EXPERIMENTS IN LYNN WOODS, MASS. It did not seem practical, however, when the experiment was planned, to attempt to settle the question by making one test. Several other screens were constructed, and one made in a similar manner to the one used on the raft at Lincoln was placed on top of an obser- EXPERIMENTS AT CLIFTONDALE, MASS. 19 vation tower at Mount Gilead in the Lynn Woods. (PI. VII.) The arms on these screens were 10 feet long and 4 feet high. The trap was placed at the top of a tower 50 feet from the ground and fully 25 feet above the tops of the tallest trees. A few caterpillars were feeding on April 29, the date when the trap was installed. The object of this experiment was to determine, if possible, whether caterpillars could be caught high in the air. The woodland surrounding this tower was badly infested, and later in the season a considerable area was completely stripped of foliage. On May 4 the trap was examined, but no caterpillars could be found. 7.. 5. eae 41 | SE. May 10; 1906 et eee es 50 | W. A glance at these tables indicates that in April, when the tempera- ture ranged above 70°, 16 days out of 20 the wind varied between south and west. For the same month during the low temperatures ‘the wind ranged between north and east for 10 days out of the 20. Corresponding figures during May show that for 18 days out of 20 the wind was from the south and west, and for 16 days out. of 20 - DIRECTION AND VELOCITY OF WIND. oo the wind was from north to east. For the years mentioned, when there were bad woodland infestations in Massachusetts, the wind during the hot days was usually southwest, which would be most favorable for the spread of the insect into the region where it has since been found in scattered colonies. The relation of temperature and the direction and velocity of the wind are intimate, as shown by the tables which follow. It has been stated that wind spread is possible when the tempera- ture as recorded by the Weather Bureau is as low as 65°, but an increase in temperature makes the chances of spreading greater. Tables IV and V give the direction of the wind for the different years, at the Boston Weather Bureau station when the temperature was 65° or higher, and the wind velocity 10 miles per hour or more. In all cases where the temperature is 70° F. or above, italic letters and figures are used in the columns of the table giving the tempera- ture and the direction and velocity of the wind. Otherwise the letters and figures are in Roman. TABLE 1V.—Temperature and direction and velocity of wind on dates after hatch- ing of gipsy-moth caterpillars, 1902-1911. (Data from U. S. Weather Bureau at Boston, Mass.) Maxi- aa Maxi- * mum| Direc- ‘ mum] Direc- : Date. 24hours. | tem-| tion of Via Date. 24hours. | tem-| tion of pelea pera-| wind. ; pera-|\ ‘wind, | °) We. ture. ture Miles per Miles per 1902. ba oe hour. 1902. OY oe hour. Ret | AM........:. Wekcae 12 || May 16| AM,PM..... 721 Woes. 20 23 | PM, AM... Bib Wess 29 i Rie ae Bie aig ae 18 24 watas « Wisees 2 26 18 | AM, PM..... 7 NW cee. 14 Piemwegeeetas..) 662 | SW... 32 Deft: UME crete care 7 SWe238 16 28 | AM,PM..... Td IN Wes awe 18 22a ea PMc oe SOAS 22 oe 23 29 | AM,PM..... (dita hare meee eee 26 23.) AMP Me 3 <. 88 | SW..... 19 io Gb) AM.......... BW... 19 24.| Ao PM... ahi alae 24 Saree EM. Wl ive wate Pata 20 20) AM es 16 WSR. of 8 | AM,PM..... 72| SW... 26 26 | AM’PM..... 80| SW... 6 a Be Sel = Sin we Gor a Wsewocas 38 ik Wo Wine toe he 7 NS ee eo 20 NG a PG | Ts 19 PA Sy as 600 Wak ee 33 OO Or WOW oceoues 14 31 MERE oe SOF Sy, ae a 17 Norte. —During the years 1902, 1903, and 1904 the Boston Weather Bureau did not record temperatv 2 . hourly, but took readings at 8 am and 8 pm each day. AM in the table refers to the reading made ‘n° the period from 8 am to 8 pm, while PM covers the following 12 hours. The direction of the winda id | its maximum velocity did not necessarily occur when the temperature was at the maximum, for the te perature may have been 65° or even less at that time. nee es aves el ee 3 Temper- _—sdDirection | vetocity Date. 24 hours. ature. of wind. of wind. | Miles 1903. os per hour. I lo Side. Gills cis oak cca bc lveseldcawnevennd«'s ees ie tees Aree 13 MENA Bete 20 vivian ee fed oe oe nab a oldies «vo osc cone shee SEN UNG Ws cm:ales wrssnp's 19 SE ee ea, Me cieemie. dae dhe c > na uewhs ses 88 | SW 28 a sac acta ap Vr a owes eine Haws s ae ook Seen sc vee as 76 | S.. 19 een Ne eo ee eS Oe eee oe oh vie bivinwia cba’ ae = 13 I Oh oe Bera s Tea ee ts reese te, Ue eee See 18 ck tN Ne OS ag) 5 ae i See ae ek 7 eee. Sued Cope 20 8 SEE, ic alah SIDS SRS FS Se ee ‘hi A eee 18 es Sete Hoes Da OE eve Sic baee sehr ev cdudescbuche Gir tibitdcewhbeonackes 10 60474°—Bull. 119—13——-3 34 THE DISPERSION OF THE GIPSY MOTH. TABLE I1V.—Temperature and direction and velocity of wind, etc.—Continued. Temper- Direction Velocity — Dats: “pte ature. of wind. of wind. Miles 1903 or per hour My cls) AMP 1) tals 2a, coos oe eee ee mee 84-|'"S e 9 TG} AM, PM 3 22.42 ats cS cee be ecm etgeaee 87 | NZ oe ee 15 pS OV WO! Ea os co eee ie ooh as a ry, A id Be le W88.\ 8S Wot 16 20) PM ACM, i, Sie re Oe Denier ee ele es ene 80: Wee 16 AMA I NCS ch eee ae sees eo ssh AES og Sa 84° | 8, SW aenee eee 18 7 Ae O'R Sa BE ee I oie eee RO em AE ALT See 8h Wes oe tees 21 BT OG Eee pie So oe oh See gets ete chen geste oe 67) NW ates 27 74 Ws Deer ees rae ah mee tas oes RAS Nae CS om 68. | Szi5 ee omens 22 aT CAVE SPE oe ee Seo Spee ke See eRe ee eres 73 1S) Wee ee 23° 28 | CAME SPM. sme cece se eRe aes oie weet ae ee 76) S42 =e 27 29") ANCAP M a cherie ot Aa ee ee ees eae ane oe 10. | Na ee ee 18 oO) AME ee ace oe oa cee ee eee are ae ee 671 IN Sotaeteeeees 18 1904. Avpre 10) {SANE Ne pete ROR ie oe er ee le a 65 19 25 |! ASME 8S oe Seed Seen a Sa ei ete Ce teem eres Cet ae te eer 68 14 Bi) AMEE 28 3 es ea ia ee Re ee ee eee 70 14 May: 3) ACM oa ee ES Ee tee ie a a Oe eh aoe 65 15 ACM, PM ee Se a roe oie ee aarti 80 Ege By AM. PM Sos ho ete eS Ie ae see aga 82 23 7 ARM, PMI Mer ere ee Sec ee cena Open ae aay 81 22 Ba AMae PM. sq cS > ale eee oe Oem ree 78 25 TO) AIM oS ere Sh So ste Pa, See te reer ee eee 72 18 DT | ASM ooo ee Sec ae Se ree ee ae ye 66 15: 12) AMES ook oot ee eee, Seine ee eee ieee res 65 10 PZ: | AIM ec cee SE Sere se Sete a. Sa ae ee 68 19 70 ie 1's Meee eee See eC eres e eate Cac Se eicgeme unlenea AiCERD AAS 69 18 0A Wa fe. EN Gel Sears i ae cee lee Sy ee CR ee cae a a I rir 17 DD) \\\ ASMA PIRI Bots ae eatcce he Sie ce a a Spc Se ict hie epee gays oe 81/8 24 93 | AIM PNM. ook oe ale smarts en ae ae mene noe mee 78 a7 DA NNN SM rc CT oes ey nel ahs uaa fag cS ele coe ON 84 |W 16 B53 1ee NE, CANES! lee ace aia econ Sn thee et te ee Th 24 26) SANT, PINES Sie Sie Ss aac SOR. anos Bee a SRS ent ees ee 87 21 2 ee. tite Sa a ae eM se Seascale 8&2 25 7A Mae 5 CR 5 | ee ee Re beeen Maree esa es Wg 75 23 BO i AON MEL ord Re Soo ete ee eer te me 80 24 BO AM PM ek os ae acoA ae ae Se ee ie eee 72 22 SINE oe wis esac me Sams ange tad ane Pe cle ra e 65 13 1905. Ape. 40) 010 a, as ovG tp: as ee eee ete as ee oe eee 66.1070 .| (SWe aero 14 to 28 20 i) 0 a7. GOVAN. WSe scree a ee eae ei ae eee eee 65: tOr707 SWese- eee 14 to 25 PA MEP Geom KOM Os sONsSS Aaa so Cth aes oeotoocdeace i Meee en 66.10.7245. S Wee 11 to 18 PAT AYE seh 110) (Ojon Sle eos a Se aaa sas Voce aosioe Ss ec 681074 |S Weeeenaeeee 12 to 26 30) L tole podlic ce epee eee eR one te Pp oe aes et ey 66 to72 | W.> NW... o. 11 to 13 May 93, | 4UOnt pomih. «Sens ae kee eae ee ee» Serer 72 10-76 |S We. oeeoee 16 to 26 6.) Siar sb oF MS penne eee cee ree tate eee eerie oer |= 60't079>| SS Wee 11 to 26 T | oPaRLOw p, Mess eee eee ee cee eee eae oe ee 66t0 83 | W., NW...... 12 to 27 B'|-3 to Bg. ams 6.0528) cde eee Ole en en eee 65 to 67 | SE, SW.......| 13 to 18 9) Tica, watol2ep. ae eee ene fea te, REN 65 to 66 | NW.........-- 20 to 27 AORSE US Roe Cn Mots Mee ee os Roh ak Asie be Sear abso ose Eecas 66: to 68") NW 2 eee 12 to 18 1 EGov: os ego) 274 Oy 101 We AHO) oh) Opie eee ER ae ean eat < 68: tor? +| (SiWeeteoeeaee 10 to 19 19: | AO a. COGS Pi ME see oe eter eee i eis aie oer ee 65:to' 68: |W 2-2 ae eeeeeee 14 to 18 22e | Wee ean CORAM Mille ere oie eee ere ete ee eer ee ee ee 66:10:71), We So eee 11 to 14 PANO RO yo 1s hot ae ae ae Same Sane Ba aio tec obe age 65/0 665) Sik o2aeee eee 13 to 14 259A. tO 6p. meee. OES ones Seen Mag Meese Cees 67 tO |S Weare 15 to 19 26) fam to 10 p: mse a eee ss soe e ee aie eee eevee 65073 SW aoe eee 14 to 35 272407 pom., 9 tol psi e. ae Ss ta cece ate eee te a 67 to; 7b: SW... See 10 to 18 28) Oia, aks GO; 5 Pail = een ieee eee hoe © a ioiselet tale ote RBtO:82- | IN Weewe noon 10 to 12 29S aera. tevO path: wea gees ees ees Pe ne eee 70 to 83 | W.,S W...-=. 10 to 14 30% 4 10S pms 2222. -- ai ee ie Mision alate Dyce Satter a 70!) IN Wea ree 0 1906. Auced |}. toG sp ames Ss... cape Bese cee Aeron he ae eee 66,10,69/) Vesna 10 to 17. 2a) 410.6 P.M... ote cake eh eeepc ee eee ae eee ee 65:10:66.) SW 2.0. enone 12 to 14. 30:) Ela: im. fo. 12 mbae seca sone ent cere aoe eee eee 66.) SWinccoc.s sees 18. Mave | 12 mi. to 6p. Mba ob eee eect en tee = ee ee ee 66:10:68!) NW’... 325055 15 to 18 Bt 8 60.8 PAM s o/s cade eichs Daze ee rate at ees te Be eed 65.10 67.) SAV ae 10 to 17 Sule oN. 10:2 PMc eae ee ee eee ee eae 6GG0N70 | INI se eee eee 16 to 28 AsO Di. MM a ais 8 cere SL. PA ee tre erie a ee G's SS Wit-s ss apeee 12. mt Ga, a. to 12m 2. bee... 2S. Seep ee eee 68 G0 FI) SW we ake 10 to 17 Ob tid. ans 10 Sp. Wisc ov. i. dicen J ocoe eee ne eee 65 to 67 | SE.,S........| 22 to 37 Phi.i2m. t6-4p: m., 11 p.m.:to 12pm eee 6b: tei69 FON 22. fo. 2 11 to 25 13 4a.m.to8p.m cde 3 tS othe ae stats Sloe ee eee 65 to 83 | SW., NW.....| 12 to 27 TB SHO DOM ie cnr ahs oo odn'nte CP eee Le See See G5 i Sisco Seaeeme 10. i% Pips pm.) 10te 1p. Mi! as \: $0 eee Pee eee TELS! SE, SU eee 10. 19:1} 12 p.m, t0.44..B1., 7a. 11 tO.11 p. Wie ei oes. 20. cere 65 to 86 Sw., NW....| 10 to 18. 22 1toip AV Dat SRC errer rere rer errr sete 68 to 70 i eet ae 13 to 16. DIRECTION AND VELOCITY OF WIND. 35 TABLE IV.—Temperature and direction and velocity of wind, etc.—Continued. / Temper- Direction Velocit Date. 24 hours. ature. of wind. of wind. oS: Miles 1906. po per hour. SE ee AGU BL IF oe wln oes 12 to 27. Bete ee 2a, 1., 74. M. t03 P.M... 2... cece eecesns G10 TO Wine oc... 3's 10 to 16. IMU RE ATR Gaara lacks kanes otis ce alsenecascencees Ga merGse | BOW -j55-}.-.06 11 to’l5. 60M 7 Shs VOTAS) faa 001 ES gee Se ae ea COTO Gale Orc 2 > os «os 10 to 13. 1907. SSE 65 TA20 OW Ses eee 14 to 30. IMs ee ne ac nie Re eels we te a seese 6sito 63 SW. - 252 16. SC) USER VOGT ye ee Gate Fe |) S230 2 13 to 26. SE a er 66. TO'72"| Wk wee see 12 to 32. SE ROUND ws ce kent ee weet scene. G8 TOTae | cS oe oe or 20 to 30. Ch AE ie LE 2) G00 0 COAT LAS SUN ee eee 10 to 19. EN et Tt 8S So tases v- Paen nee 6S te'70" oS Wes. kes eae 10 to 14. Pp MEM IN TNIIEREIA eet osio <=. = Ean wie ee 6 See Sete See cee. 69:40 ST | OW ss. ee sede 10 to 17. SN ee ee a ee 65 to'67 | SW., NW... -.. 10 to 19. 1908. EE TO TOSS | SWson: vs eo 11 to 20. 2 OR. SS 1) JUTE 00 | Sa ees eee ae CO TOTSGAI AS Wace &- cates 10 to 18. ONE SS 1 a ee er 66 to 81 | SW a: 7.253 10 to 17. me Pawnee ca. >, 7 a.m. t0 12 p.m........2...--.--% CRO EL | Ss 2 rae Bae 10 to 30. NINN See gYID ie a Sale ee Seca econ ede s ees 70 to 75 | SW., NW....| 11 to 18. a VOCS TS Te oS eS ee GD COGS WS Ss se ose 15 to 16. ie LT RDS OS ee Gaon Loe SY wag Son acta 12 to 16. a a oe ee a COMO DOC WISe acetone Seen 10 to 17. Te OMl I TMs oS oe os sca waste ecie sce ccc clbessecsees 66 to 77 | S#., SW...<.. 10 to 14. 24 | 12p.m. to 10a. m.,12m.tolp.m.,11p.m.to12p.m. 65 to 78 | SW., NW....| 10 to 13. “a |) ) 2 UES TS UAC ge en CG LONSe PS inne eee 10 to 27. Pee aietO ep). 9 to LO p. Mi... 2.2 2. ee eee eee 69 to 88 | SW., W......| 10 to 18. EH THEOLON ZIP IN 2's oS oc codes ccecccccncaeeesece GOTO SOs |S act one ee 10 to 13. a ea OL. oI. ono2. 2.2522 te esl oc wy wl cee Se as Gb FOGG (WEI sass nee LitoZ: TERR SEMEN EM oo oie cniasiz oo soc we eo eee weds ecenees GEOG |) SW. 8. oe 10 to 19. 1909. oe aS ree 665to 68-) SW... 222-2... 11 to 13. RMINEMMNCDT OES (MIL oho eo ecco e se eee ene nate 68 to 83"| SW., NW..2..| J1t0 17. eae ES 6 On | Rr aa aS 0 | ee ae 11 to 27. i Sa COr LOVE el ING ee ete 10 to 22. So TEE TTS 0 Garto.7@ | NIWA 2 =. oo Ae 11 to 21. Pre ate lia. I, tO.9 Pp. WM... 52-2. ee ce eee eee ee GOTO. 47.|, SIV a2 son 10 to 19. II NIIRIIEIISED oon SS. oro oon wisn ea dos s0 dew tec cms 16tO' 81 | SiWE, NW. ace Le tous. 0 8 PE 0 yo aa ae GAWtOLT EEA sec ere ee 10 to 16. STR S eenc' 2.2 8 soi mei ence cece see sewers OD:COE WINS sees oo 12 to.18. RIERA oe we en ie nese lene 660.765) SW s-2 520s. 10 to 17. PME NIMEER EIS TIY is 8 | oe ob we nee se wiceetee acces et 6D COGS: SBE oee ee sues 15 to 17. TDA ER 7 0 oe 1 Lita 0 wr (0 I! Coe ee ee eae 14 to 26. UI TS CE 4 0 SS GOitOISO! (ONE sede <5 See 11 to 20. 1910. INT 105 TUE oc oo oie cg ew oe eee ee eee eee eee OW CaS de ea te 10 to 13. SS ee ee 65 to 67 | SW.,NW., W.| 10 to 13. nn en nceencneceSae ss 65 to 69 | W., NW...... 10 to 17. 15 | lla.m.to5 p.m GRIT a CIN WP ean se reed 11 to 15. 19 | 5to6p.m BOO OZ. | Bieo. 4.5 26s) sa- 12. 20 | 2to4p. GH TOOS HH S Wises ects os. 17 to 18. 27. | 12m. to : 66 to 69-| SW., NW..... 11 to 14. 3to6p.m OG; -EWMicte.2<<- 65. 10 to 12 May 7/1la.m.to8p.m Ob te.70 | VW. . ncn. 10 to 17 lla.m.to3 p.m BONG TS PW ee xe oh = 10 to 18 10} 12m. to6 p.m Bote. 68.) NW cages asc. 15 to 27 11 | 12m. to3 GR tA BG OW ao ot an kts 3 13 to 19 17 | 2to8p. OG TT TD) |: Bac nts 2x08 10 to 12 18 | 10tolla.m Gas WRW a dine = seed 18 19 | lto6p. 65; b0' 68") (NW: . seo 17 to 26 20 | 3to7 CBT | WF aca: cine 0K 10 to 14 23 im. $07 p.m AL OE AN eS ee ee eee Gb TO Ca |S Wreaes en Sant 11 to 15 eto oa, 20..7 (0 108. 10.,12 m. to ll p. m....-.-....... GO tO8E: "8 Wen. ccna aes 10 to 17. ae ean. 10 08, 1.,69. Mm. to8 p. M....-..-..-- 2c. e ene Dag OW ES eR CoO eee 12 to 17. EE FO, Wao ae nan pacar wane CeApevevesassswnsae 68 to 76 | SW., NW.....| 11 to 14. ICL a iss awbagicn xe o6.0sciathas so 0m10\s= cele a ty ona OD PWN sinlcdince 40 pat 11. LE citi te kp an cninm oer omekh aetadcuasenaks aus a ek Pee 12 nt wri knethenackkursNc>adstadusnvesss> ass OD.) Biicds 2 8 GON Hae oe ee rea rat ee east eT eee errr 66: Woh eee 18 to 20 7 | '8:00'9, LOGO Gx-kes sete eee ea ae oe he ere oats 68 to:80 | W.5 IN Weeseee 10 to 18 Bh EO GO ee aes eager a ee ae a eS a GROOT O82) Sota eee 13 to 19 10 | 8 to 11; 1to.3, A toiGs. pees ee eee ee ee oe 65t075 | NW., N.,S...| 10to 15 12-6 C07 21010 Zoe 2 et eee pete ne nee ee ere ees 66 10 722) S., So Weeeeeee 11 to 18 138 tO: Sok odbc See eke eee ee Soe oe ee Cerone 66to76 | W., NW....-.- 14 to 20 16>) 1O't0 6.50 os seen oo Aenea Aas et Soc See eee ee 65 t078 | IN W., Weeeese 12 to 16 q Ta ADO eee rte oe ee ee ee ee ee 61S ae eee 1 iS OS Ws 9 mee i Ae gery eA ee Ne We ae ae Ye OS Ce 67 st0! 7 Sees oe 1 USD COND, a od ne ee ce ae Arce a os, a eae Or CS AO TSA SEs ee eee cee 11 to 18 Deh C2 COD. ts ,o08 oe Sepa ate ake eres as ean ee ieee =o ee 84 tOr88. Sie ees See PH iy Wee I 0 i ae ma gE pe teh a MG am ees ag ya OAT 65 to'69)|:S'. 20 ese 12 to 16 2S (OTOL Oo ec ce Bee See ee ee ie ee ee ele poe eee ae 6671076 |S) eee 11 to 20 BOR DCO Ae oo ee a oe eS Ee Sais tte Male = arene Teen Ph 10:80 So: 2 eee 10 to 12 BO ll OMAR, aes abe 8 eS eR ah oct ea ccna n Se SE ets ae ete ee 66 to'700\ Sts 2 eaeeeeee 10 to 13 In order to study these tables properly the data from each State should be considered separately. Hatching takes place later in the vicinity of Portland, Me., and Concord, N. H., than in the terri- tory surrounding Boston, because the season is later. In Massachu- setts the same conditions prevail in all of the towns which are on the watersheds of the Merrimac and Connecticut Rivers. An ex- amination of the records, however, shows that the prevailing winds DIRECTION AND VELOCITY OF WIND. 39 are in the same direction during the first half of June as in the month of May, so that little benefit would be derived from giving the additional data. For convenience the record of infestation has been divided into four periods (see map 1), viz: (1) The territory infested in 1900 at the time the work was dis- — continued by the State of Massachusetts. (2) The territory found infested as a result of scouting operations after the work was resumed in the winter of 1905-6 by the State of Massachusetts. (8) The territory found infested up to and including the winter of 1908-9. | (4) The territory infested at the present time, winter of 1911-12. The territory infested in 1900 when the gipsy-moth work was discontinued by the State of Massachusetts was confined to 34 towns and cities surrounding Boston, covering an area of about 359 square miles. None of the area was badly infested, but a very rapid in- erease of the pest took place as soon as efforts to check it were abandoned. The next two years developed few signs of increase in the insect, although in several localities it was somewhat abundant in 1902. An infestation was discovered in Providence, R. I., in the summer of 1901. In the summers of 1903, 1904, and 1905 the terri- tory in Massachusetts which had been most densely infested when the work was discontinued fairly swarmed with caterpillars, and, as little organized effort was made to check the insect, an excellent opportunity was offered for the small caterpillars to be spread by the wind. Map 1 shows the territory which was found infested by the scouting operations conducted by the State of Massachusetts, which were carried on during the summer and fall of 1905. The infestation had increased to such an extent that it covered 132 towns and extended from Portsmouth, N. H., to Buzzards Bay, including, as well, isolated colonies in Providence and Cranston, R. I., and Ston- ington, Conn., a total of about 2,224 square miles. Undoubtedly the greater part of this infestation was the result of wind spread, therefore map 1 indicates the number of days the wind blew in each direction during the period when caterpillars were in the first stage, and when the temperature and wind velocity were favorable to their dispersion. Eliminating the west wind from consideration, which would take the larve out to sea, it will be noted that, except for seven days when it was from the east and north, the direction of the wind would account in a general way for the infested region as shown by the map. It is probable that more area would have been found infested in southern New Hampshire in 1905 if it had been possible to scout the towns nearest Massa- chusetts, but there were no funds available for this purpose. 40 THE DISPERSION OF THE GIPSY MOTH. During the period from 1906 to 1909 a large extent of scouting was done by the State of Massachusetts in the territory outside of the area known to be infested, and, as a result, 44 new towns and cities were found infested. Isolated colonies were found at Green- field, at Palmer, at Springfield, and at Warren during the scouting operations, but all of them have since been exterminated. In New Hampshire scouting work was carried on under the direction of Mr. D. M. Rogers, special agent of the Bureau of Entomology. The infested area was found to have greatly increased. Scouting was also carried on in Maine and Rhode Island and showed that the infested area was increasing, and one isolated colony was found in Togus, Me. At the close of this period of scouting the entire area of infestation covered nearly 7,300 square miles. The greater part of the spread had been toward the northeast and northwest, and it is interesting to note that the prevailing winds blew in these di- rections, especially from the southwest. (See map 1.) During the period from 1909 to 1912 the infested territory has continued to increase. Nearly all the scouting work has been done by agents of the Bureau of Entomology, although a small force has been employed by the States of Maine, Massachusetts, and Con- necticut. The infested territory has continued to increase along the line of the prevailing winds, as is shown on map 1 and by its wind diagram. In the fall of 1909 an isolated colony was found at Wallingford, Conn., but careful scouting for miles in all directions has failed to locate other infestations in that part of the State. It is probable that egg clusters were brought to Wallingford on market boxes or in packing material. The thorough treatment which has been given under the direction of the State entomologist, Dr. W. E. Britton, and his assistant has reduced the colony to a point approach- ing extermination. The same is true of the colony at Stonington, Conn. | In the summer of 1911 the gipsy moth was discovered on an estate in the town of Lenox in the western part of Massachusetts, and scouting work has resulted in locating it in Stockbridge and Great Barrington. It is probable that in Lenox and Stockbridge the in- festation resulted from the receipt of a carload of nursery stock (Pls. XIV, XV, XVI) which was shipped by the Boston Park Department about 1909 to the estate where the infestation was found. The origin of the Great Barrington infestation is obscure, but fur- ther scouting of the town may uncover conditions which will explain the reason. The colony at Togus, Me., has been exterminated, no specimens having been found since 1908. As a result of the scouting operations during the past winter it is shown that 10,900 square miles are now infested with the gipsy moth. The territory which is now badly infested is well outside | Bul. 119, Bureau of Entomology, U.S. Dept. of Agriculture. PLATE XIV. Row OF LARGE MAPLE NuRSERY STOCK INFESTED BY THE GIPSY MOTH. A gipsy-moth egg cluster is on the tree in the center of the picture, as indicated by arrow, just above the black spot. (Original.) Bul. 119, Bureau of Entomology, U. S. Dept. of Agriculture PLATE XV. GIPSY-MOTH EGG CLUSTER ON SMALL NORWAY SPRUCE TREE IN NURSERY ROW. The upper branches of the tree have been tied up so as to expose the egg : cluster. (Original. ) a Bul. 119, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XVI. WEEPING MULBERRY SHOWING BIRD’S NEST AND NEAR BY TWO GIPSY-MOTH EGG CLUSTERS. Their location is indicated by the arrows. The egg cluster in the background is nearly obscured by the shadow. (Original.) ie a Rr ee ok COE ae Fs i ANG OQC, WAT2 ya A 7tG2 Driv, im’ . Mi fs BE ss fan Sl ee ‘ lia it eS ee Bul {19. Bureau of Entomology, US Dept.of Agriculture MAP No, 1. Ke on ‘ Boston, Mass., 1909-191 1. 1 13 1 7 0 rane 32 8 ZZ Portland, Me., 1909-1911. Concord, N. H., 1909-1911. CG ACH USETTS BAY \ 1 1 0 1s 0 10 0 8 2 2 S 13 15 19 WIND CHART. 3 Wind chart indicating total number of days in which the wind blew in the directions of the arrows, for April and May of the years mentioned and when the temperature was above 65°. These were the days favorable for wind spread. Colored circles show area to which larvz@ were dispersed during the period. MAP =) —~ Z showing DISPERSION ano PRESENT DISTRIBUTION of the GIPSY MOTH 'v NEW ENGLAND. TOWNS AND CITIES WHOLLY ORIN PART (NFESTED 1M (DS) 1900 WHEW Work UNDER BOARD OF AGRICULTURE WAS DISCONTINUED. TOWNS AND.CITIES FOUND TOBE INFESTED AFTER TOWNS AND CITIES FIRST FOUND INFESTEL Hee ee Wee HAs REAUNED IH (908 aS PEGE STEMI I09 1918, Sess TOWNS ANDCITIES FIRST FOUND INFESTED 1906-7909, Reh Mere 4 — mmm mre “ ar Aine ty Lo ‘ + ce me a ax at Nit, Anakin Sh cilia ing ; a BY te ale § i VF AD Clon ae ok ? "a free. j ; & 7 — c ‘ , F | t | . * a "y ; < “ ‘ f . | i} £ % iF x i o< 5 } : By (et, ’ bee f c + > ri : to t T ~ 3 ; 4 \ ae : 1 Ty , ~ A f - =A ; : A . 4 _ N } * tute i* ; i ' ~ > >". fi ee wo. eh ,o4 Bi , Deemer earthed a eg a te % 4 , 5 £ “, ‘ a7; pt GENERAL CONCLUSIONS. 4] of that which was infested in 1905. This being the case, the oppor- tunity for spread has greatly increased, and as the insect gradually becomes established on the western slope of the high lands in the central part of the State, the opportunity for serious damage in the Connecticut valley is rapidly increasing. In connection with the weather record given for this period it is interesting to note the corresponding data from the Weather Bureau stations at Portland, Me., and at Concord, N. H., as these data have a bearing upon the spread in the northern part of the territory. GENERAL SUMMARY. The map and wind direction records give a fairly good idea of the dispersion of the gipsy moth. The spread has been along the lines of the prevailing winds to so great an extent that the evidence is con- clusive that natural spread is accomplished chiefly in this way. All the records bear out this conclusion. It should be noted in the Con- cord records that the southeast winds were the ones which were most likely to carry the larve into new territory, while in Portland the south and west winds which predominated would do the same thing in that section. It should be remembered that neither Concord, N. H., nor Portland, Me., has been badly infested and that the spread must come from bad colonies nearer the center of infestation. The general “seeding down” of slightly infested territory by larvee spread by the wind is shown in some detail in the following pages. GENERAL CONCLUSIONS. It is impossible to give a detailed explanation of the cause of every infestation. The weather records give strong evidence that the wind is responsible in a large degree for the spread of the gipsy moth, but the spread can be brought about only under the favorable conditions which have already been explained. The present apparatus for recording wind movements is somewhat imperfect, and as the wind is usually very variable it is probable that a greater local spread results than can be explained from wind records. Other things being equal, wind spread will start the most vigorous colonies nearest the bad centers of infestation,’ for the farther the caterpillars are carried the more chance there is for them to become widely separated, so 10n May 19, 1912, Mr. C. W. Stockwell found that large numbers of first-stage gipsy- moth larve that hatched a few days before were being blown from an isolated block of birches into a pasture by a strong southwest wind. At a point 125 feet from this bloek he found from 21 to 27 larve per square foot; they were crawling about on the grass seeking food. On the posts of a wire fence, 185 feet from the birches, over 500 larve were found on each post, and smaller numbers of larve were found at a greater distance away. This substantiates the experiments previously made, and shows what happens in nature under favorable conditions. It also proves that the heaviest infestations brought about by wind spread will be nearest the colony from which the larve were spread. 42 . THE DISPERSION OF THE GIPSY MOTH. < that infertile egg clusters will result in case any are deposited. Cases are on record where a male gipsy moth has been attracted half a mile | by a female. This factor probably assists the species in becoming established at distant points. RELATION OF SCOUTING RECORDS TO WIND DISPERSION. The records which have accumulated showing the number of egg clusters found and treated by scouts in the various towns, as well as the reports of the work done by local superintendents, have been _examined for the purpose of determining whether information could be secured that would have any bearing on the dispersion of the insect. As a result of the examinations it appears impossible to give data covering the entire territory, since the records are incomplete ™m many cases and they have been kept in various ways so as to make a comparison of little value. The plan has been to select several — towns and cities (see fig. 4) where complete records were obtained. The geographical locations of these are typical, so that the results will serve to illustrate the relation of wind to infestation as found by scouts. It should be remembered that no woodland area is in- cluded in the records cited, for only roadsides, orchards, and the erounds about residences were examined. In order to check this data a complete scout has been made of several towns by employees of the Bureau of Entomology, United States Department of Agriculture, working under the direction of Mr. Rogers. This included a careful examination of the wooded areas as well as the roadside trees. RECORDS OF DISPERSION OF THE GIPSY MOTH SECURED FROM REPORTS OF SCOUTING IN SEVERAL SELECTED CITIES. For the purpose of making a comparison showing the rapidity of infestation in different localities (fig. 4) the cities of Brockton and Worcester, Mass., and Nashua, Manchester, Concord, we Portsmouth, N. H., are given in Table VI. TABLE VI.—Record of egg clusters of the gipsy moth found in certain cities of New England during the years 1905-11. Cities. 1905-6 1906-7 1907-8 1908-9 1909-10 | 1910-11 Massachusetts: IBTOCK(OM MS. ec Seton tates arenes ae 24 127 283 3,101 1,575 5,600 WV OT CCSLOIAE op sts eaeter toca exons 0 44 275 New Hampshire ASHUG foe bys as cdeioe cee nsee creer 0 9 176 910 16, 759 117,607 IRTATICN CSR oF Ree oe ieee oat ae 0 2 53 456 (2 ) 1 16, 598 POMCOTALS. oe aN ar oe ae ete eno 0 0 (3) 93 1,855 4,419 IPortsmomiure. soe os eae eee ee 2 175 802 9, 417 72, 294 1 72,000 1 Estimated. 2 No record. 31 pupa. RECORDS FROM REPORTS OF SCOUTING. 43 The records for the winter of 1911-12 are not given, as it was impossible to secure the information from some of the cities men- tioned. The data concerning the infestation in cities and towns in Massachusetts have been kindly furnished by State Forester F. W. Rane and his assistants, while similar data from the other States have been supplied by Mr. Rogers. It will be noted that the city of Brockton was found infested in 1905-6 and that the same is true of Portsmouth, N. H. An excellent opportunity is offered for comparing the number of egg clusters found in these two cities from year to year. It will be observed that at the end of the fifth year 1,575 egg clusters were found in Brockton, while over 72,000 were treated in Portsmouth, N. H. This indicates very strongly that new infestations were continually being brought about through the spread of caterpillars by the wind. Somewhat the same conditions will be noted on comparing the record of infestation at Worcester with that of Nashua, Manchester, and Concord. The increase in Worcester for the period shown in the table is slightly less than that in Brockton, which shows that the wind was more favorable for spread in the direction of the latter city. It should be noted that all the newly infested points were treated each year, and in many cases colonies were exterminated, but as a rule a larger number of new infestations were found in different parts of the cities the next year, and the total of egg clusters usually showed an increase. In connection with these data it is interesting to consider the record of infestation in the State of Rhode Island. The gipsy moth was first found in the city of Providence in 1901, and some work was done to control the insect during the five succeeding years. In 1906-7 a careful examination was made by agents of the Bureau of Entomology in cooperation with the State of Rhode Island, and several towns surrounding that city were found infested. In all, 79,000 egg clusters were found and treated. In 1907-8, 7,500 egg clusters were found, and the following winter only 1,164 were dis- covered. During the next two winters there was a slight increase in the number of egg clusters found, as several newly infested places were discovered. No work was done in the summer of 1911, because the State failed to provide the necessary funds. During the winter of 1911-12 an examination made by the agents of the Bureau of Entomology showed that the insect had increased rapidly, 37,293 egg clusters having been found and five new towns having been infested. The territory infested includes both city and country, and the figures show how rapidly reinfestation takes place after suppression work is stopped. The data also indicate that the rate of increase is — 44 THE DISPERSION OF THE GIPSY MOTH. . 7 oa e* oo - USM | RoYDON fey ws (SALISBURY >A Le) fw 1 Why WER Sonos DFORD “Wo Na ae \ *htNr9 5 - ENNIKER N \ LJ Wey Cop \uonpan OERAY a\ DERRY Z Pp . aRL-\ OUBLIN ea < ) BOR o* eA eS Syst yroy \AFFRE ~ = Bs 4 PELHAM MOND\ FITZ- - ol WILL! \ WARWICKY ROYAL STON | yin cHaN- Ar S= wee ‘ FIRES YER’ 3 gz ea 4 Sy f z , ———L €0- \ INSTER o\ = “e et Jar pouTon) syd Yo} * DBURY ra Ef RANK RANK dl Lin Py r fi UMBER-& . a ; 1 Feyarniviste y F\EANe [: “< \\ Lh d ly PLYMOUTH \\ HOMPSON y wooosrock \t ‘ %o) \ \ w ci we 2A eon } ih. ‘Catnarty COLCHESTER Ir'ic. 4.—Map showing location of towns and cities in New Hampshire and Massachusetts where scouting records have been consulted: to compare the relation of infestation to wind spread. (Original.) RECORDS FROM SELECTED TOWNS. 45 much less in this State than in the cities in New Hampshire noted in Table VI, which is due largely to the fact that the region is out of the line of natural spread and reinfestation by the wind. The common trees growing in Rhode Island are as much if not more favored for food than those in the cities mentioned. RECORDS OF DISPERSION SECURED FROM SEVERAL SELECTED TOWNS. In order to check the data just given the records of several out- lying towns (fig. 4) in different sections of the infested district are supplied in the accompanying table. TABLE VII.—Record of egg clusters of the gipsy moth found in certain towns of New England during the years 1906-1912. Pe PE ee x : Towns. _ 1906-7 1907-8 1908-9 1909-10 | 1910-11 | 1911-12 Massachusetts: | ee 3 8 47 141 503 1,789 0 ae iri 267 1, 417 4, 283 2,124 3, 448 (1) ae ec Ne Miewosemnlevc cass sc|e os oe oct. 846 | 1,897 2b oe oe 2s ee eg 2S ee ae as ae cee ee eR ae (3) 14 341 | 142 OL oso Sdok cee! seGe ce SOeSe Seal Gea paees eee an eee eee 1 140 | 1, 421 aE Sell RES oe (ee ee, ban 7 156 378 TIRE See hae oe ed eee ae eee (ite see. 9 45 455 ECU ER ET Oe gee eek en OEM Moot Sess 32 12 3 4 33 eenIeTOUlpe 8 cs Se 2. Sen ccd mos 4 87 765 (*) (4) 1 ar el ee 1 4 524 3,613 412, 862 New Hampshire: D0 0 a ae beeen See eee alee ent Ee 25 308 2,825 42,147 IIE ee oo ge sce eww ae ete rectaael reece es 125 1,170 3, 260 (1) | 1 No record. 27 collected. 31 pupa. 4 Partial record. The record of infestation—that is, the record showing the number of egg clusters found while scouting various towns from year to year—is interesting, as it gives in a way the rate of increase, although it should be understood that all egg clusters which are found are treated with creosote, and in most cases the infested areas are attended to during the caterpillar season and all the larve found are destroyed. Only roadsides, orchards, and private estates are ex- amined and treated. In most cases the towns have large woodland areas which it is impossible to examine owing to the expense involved, The record of the infestation is given for several towns, which shows that dispersion must be due to causes other than vehicles. The data for the town of Easton were furnished by Mr. L. W. Hodgkins, an agent of the State forester of Massachusetts, who had charge of a section of southeastern Massachusetts.for several years. The town has been examined and the infestations treated each year, the number of egg clusters showing a slow but continuous increase since 1906, the year when the first infestation was found. During 46 THE DISPERSION OF THE GIPSY MOTH. ~ that year single egg clusters were discovered in each of three locali- ties. In the fall of 1911, 1,789 were found in 326 localities. The gipsy moth was first found in Hopkinton, Mass., in 1905, and the writer is indebted to Mr. G. A. Sands, of the Massachusetts State forester’s office, for data concerning this town. During the winter of 1906-7, 267 egg clusters were secured from 39 different localities. In 1907-8, 1,417 egg clusters were secured in 30 localities. In 1908-9, 4,283 egg clusters were found in 90 colonies. In 1909-10, 2,124 egg clusters were treated in 70 localities. In 1910-11, 3,448 egg clusters were found in 80 localities. In some of these colonies no egg clusters were located during the year following the first examina- tion, as the trees were burlaped, examined during the summer, and the colonies exterminated. In other places small numbers of egg clusters were found from year to year, but each year it was possible to obtain them in regions where they had not been known previously. The original colony in Hopkinton was southeast of the village, near the roadside. The following year infested places were found near the center of the town, and a few were located near the borders of the adjoining towns. The next year egg clusters were found well scattered throughout the town, especially in the residential section, and this condition prevails at the present time. Owing to the loca- tion of the various infestations, it is highly improbable that the insects could have spread by artificial means. For the past two years very little work has been done in this town to suppress the moth. | The data for several towns following were supplied by Mr. H. B. Ramsey, an agent of the Masachusetts State forester, and the writer is indebted to him for this and other valuable information fur- nished. | The condition in Westboro, a town northwest of Hopkinton, was not so bad in 1906-7, there having been found at that time only seven colonies. The number of colonies, however, steadily increased. In 1910-11, 116 were located, containing 846 egg clusters, while in 1911-12, 1,897 egg clusters were found in 214 localities. Directly northwest of Westboro is the town of Northboro, in which no egg clusters were found until the winter of 1909-10, although three pupal cases were secured during the previous year. Northboro is west of Marlboro, which was found infested in 1905, and if dis- persion of the species was equal in all directions, should have become infested rapidly. During the winter of 1909-10 five colonies were found, 14 egg clusters being treated in them. They were located in the southeastern and north-central parts of the town. The fol- lowing year 95 colonies were secured, and in these 341 egg clusters were treated. In 1911-12, 1,421 egg clusters were found on 180 * RECORDS FROM SELECTED TOWNS. 47 estates. The colonies were scattered through practically every sec- tion of the town, a few more being found near the center than in the outskirts. Northwest of the town of Northboro is the town of Boylston (fig. 5). One egg cluster was found here in the winter of 1909-10, and during the following year 140 were found in 41 different locali- ties. In 1911-12 141 egg clusters were found in 41 localities scat- tered over the town. West Boylston, a town directly west of Boylston, was scouted by the inspectors employed by the State of Massachusetts in the winters of 1907-8 and 1908-9, but no egg clus- _ ters were found. During the winter of 1909-10 seven were secured on five estates, and during the following winter 30 estates were found in- fested with 156 egg clusters. During the winter of 1911-12 378 egg clusters were found on 75 estates. The town of Holden, which is directly west of West Boylston, shows an increase quite similar to those already mentioned. A single female pupa was found during the winter of 1907-8, but the follow- ing = nothing os Fie. 5.—Map of town of Boylston, Mass., showing in- discovered when the crease in gipsy-meéth-infested localities, 1909-10 and ScOmtwas made. Inthe 1910-11. (Original. Bier of 1009-10: rine, © Mavs fnertstion fou tn wins 1000-10 estates were found in- fested, each with a single egg cluster, while in 1910-11 10 estates were infested with 45 egg clusters. In 1911-12 a large increase was found, 455 being discovered on 67 estates. The city of Worcester is located south of Holden, and was first found infested in the summer of 1907, when Mr. D. M. Rogers found a few caterpillars on an estate on Hope Avenue. During the winter of 1907-8 the city was scouted and 44 egg clusters were found on seven estates, These were well scattered over the city, and, owing va “3 % 48 THE DISPERSION OF THE GIPSY MOTH. to the large traffic by automobiles and trolley cars from the badly infested district in eastern Massachusetts, it is very probable that the infestation may have been brought about by the carriage of cater- pillars in this way. These colonies received careful attention during the summer. In the winter of 1908-9 16 estates were found in- fested with a total of 32 egg clusters. Fourteen of these estates were near Worcester Academy; the othe: two were in the eastern section of the city. Only a few egg clusters were found on the estates which were infested the previous year. In 1909-10 10 in- fested estates were found, with a total of 31 egg clusters, well scat- tered through the city. Only one of these was on property which was found infested the previous year. In 1910-11 275 egg clusters were found on 145 estates, every section of the city being included in the infested area. In 1911-12 3,570 egg clusters were found on 424 estates. It seems probable that during the period from 1907 to 1910 the greater part of the infestation may have come from traffic, but one can not escape the conviction that during the summers of 1910 and 1911, as the infestation to the south and southeast became more pronounced, a large number of the colonies resulted from wind spread. It should be remembered that the chances for spread by traffic in a large city are far greater than in the country districts. The data concerning Worcester are given because the city resembles many of the towns mentioned, inasmuch as it is very hilly, so that spread by air currents is very probable. The town of Millbury, which adjoins Worcester on the south, has a record which is of considerable interest, inasmuch as the infesta- tion has been decreasing from year to year. In the winter of 1907-8 32 egg clusters were found on five estates. These were all located in the central part of the town not far from the railroad. The following year no new egg clusters were found in these localities, but two other infestations, containing 12 egg clusters, were located, one near an infestation of the previous year, close by the railroad, and the other a considerable distance west of any previous infesta- tion. In the winter of 1909-10 three new infestations were found, each containing an egg cluster, but no clusters were found in the old infested area. In the winter of 1910-11 nothing was found in the area infested the previous year, but three separate infestations, con- taining four egg clusters, were found in the Bond Hill section of the town east of the railroad. In 1911-12 33 egg clusters were found in six localities. The conditions in this town are quite different from those in any town previously mentioned. So far as is known, no bad infestations occurred in the region directly south, so that there would be far less opportunity for spread by the wind than would be the case in the other towns mentioned. It seems probable RECORDS FROM SELECTED TOWNS. 49 that early infestations may have been brought about by automobile traffic, but this, of course, can not be proved. _ The data from the two towns of Pepperell and Townsend, which are nearly due north from the towns already mentioned and are bounded on the north by the New Hampshire State line, have been furnished by the local moth superintendents, Mr. J. Tune and Mr. George E. King, and are given, as they show a contrast in the increase in infestation over most of the towns already mentioned. The town of Pepperell was found infested the same year as were the town of Westboro and the city of Worcester. It lies about 40 miles north of Westboro, and instead of immediately adjoining towns that were infested with the gipsy moth in 1905, as was the case in the town of Westboro, it is located more than 12 miles from the nearest town that was found infested at that time. In the winter of 1906-7 4 ege clusters were found near the center of the town by State in- spectors. These were properly treated, and during the following winter 87 egg clusters were discovered and creosoted. In the winter of 1908-9 756 ege clusters were found, and since that time the insect has become so abundant that no effort has been made by the local moth superintendent to keep a record of those that were found and treated. The town of Townsend adjoins Pepperell on the west, and was first found infested one year later than the towns of Pepperell and Westboro, and the same year as the towns of Holden and Millbury, a record of which has already been given. The infestation in Town- send is interesting, inasmuch as the record has been carefully kept by the local superintendent, Mr. George EK. King. In the winter of 1907-8 1 egg cluster was found in the western part of the town. It was treated with creosote, the trees were burlaped, and later 5 caterpillars were found and destroyed. In the winter of 1908-9 1 ege cluster was found in the eastern part of the town and treated in the same way, and 3 egg clusters were found near the center of the town, and as a result of burlaping 15 caterpillars were killed during the summer. The following winter 65 different colo- nies were found scattered throughout the town. Five hundred and twenty-four egg clusters were treated and 10,500 caterpillars were destroyed during the summer. During the winter of 1910-11, 245 colonies were found scattered throughout the town, a large number being in orchards along roadways. In these colonies 3,613 egg clusters were destroyed, and later in the season about 20,000 cater- pillars were killed. On February 27, 1912, Mr. King informed me that 12,862 egg clusters had been found in 257 localities, and that the work for the winter of 1911-12 was not nearly completed. The increase in the number of colonies found and the number of egg clusters and caterpillars destroyed is in marked contrast to the 60474°—Bull. 119—13——4 50 THE DISPERSION OF THE GIPSY MOTH. record of infestation of Westboro, which was much nearer the badly infested territory, and, other things being equal, should have become badly infested sooner than Townsend, where the first infestation was located a year later. The scouting of Dunbarton and Farmington, N. H., has been car- ried on by scouts working under the direction of Mr. D. M. Rogers, and Table VII shows that the infestation has been greater than that in the towns given in central Massachusetts, and about the same as that found in Townsend. It will be observed that in Westboro seven colonies, containing 377 egg clusters, were found in 1906-7, which indicates that the moth was present the previous year, and probably would have been found if there had been sufficient time to make a thorough inspection. In the winter of 1911-12 214 colonies were found and 1,897 egg clusters were treated. When this is compared with the record given for Townsend, which started from one egg cluster in the winter of 1907-8, one can not escape the conviction, inasmuch as most of the infestations recorded in the winter of 1911-12 were in localities which had previously not been known to be infested, that the rapid infes- tation of this territory was due to the dispersion of young caterpillars by the wind. PLANS FOR SCOUTING WOODLAND AREAS. Many data have been given showing that the dispersion of the gipsy moth is largely due to small caterpillars carried by the wind, but it seemed desirable to determine whether the woodland areas in the towns where only a few colonies existed were becoming infested by this insect. The matter was thoroughly discussed by Messrs. Fiske, Rogers, and the writer, and as a result plans were made to scout large areas in several of the outlying towns. The plans were approved by Dr. L. O. Howard. It was arranged that the scouting work should be carried on under the direction of Mr. Rogers, and it was begun in October, 1911. Owing to the severe winter and heavy snowfall in the infested territory it was impossible to finish all the towns until late in the spring of 1912. The work was carried through, however, and a statement of the results follows. The original plan contemplated the examination of every tree in the whole or a part of the towns of Lisbon and Yarmouth, Me., Milton, Tilton, and Bennington, N. H., and Gardner, Grafton, and Wareham, Mass. (See fig. 6.) It will be noted that these towns are located in the sparsely infested area (map 1),and it was expected that some interesting data on wind dispersion would be secured. Work in Bennington, N. H., was carried on under the direction of General Foreman I. L. Bailey; that in Maine and in Tilton and Milton, N..H., and Grafton, Mass., was directed by General Foreman H. L. McIn- RECORD OF SCOUTING IN LISBON, ME. 2 ok tyre. The work in Wareham was carried on under the direction of C. E. Totman and C. B. Whitaker, while that in Gardner was di- rected by Henry N. Bean. It should be noted at the outset that the character of the forest has a great influence on the liability to infesta- tion, because if the caterpillars are carried by the wind and dropped upon trees upon which they can not feed, no infestation will result. Therefore it is to be expected that in sections where coniferous trees predominate the chances of new infestation will diminish, even al- though the region is in line with the prevailing wind during the time the caterpillars are likely to be carried by it. RECORD OF SCOUTING IN LISBON, ME. On October 23, 1911, the work in Lisbon, Me., was begun by Mr. C. E. Totman and a crew of experienced scouts, and the territory north of the Androscoggin River and east of the Maine Central Railroad was examined. This covered about 164 square miles, about 40 per cent of which was woodland. The land in this town is rolling. and a considerable portion is cleared and cultivated. The percentages of the various kinds of trees in the regions scouted were estimated by Mr. Totman, as follows: Per cent. Per cent. a Pe eee 2 rt at es aE NE aw 2 a ES a tee Mena ICN ese tes we) Sadan SP Vai A 7 8 EE a ee ene RY eae te = Re Bees 18 ee mb) Da SON anCOme et Fat eh 6 It will be noted that about half of the food plants (conifers and ash) are unsuitable for food for first-stage gipsy-moth caterpillars, so that of the 16} square miles covered only 3} square miles of the area supported trees upon which the gipsy moth would survive if it were introduced. The oak, which is the favorite food, comprised only 3 per cent of the tree growth. Roadsides in this town were scouted in the winter of 1910-11, and nine infestations were found in the territory under consideration, a single egg cluster being obtained in each locality. These were treated at the time. The results of the present scouting showed that no infestations were present where eggs were found last year, but 18 new infestations were located. Only one of these was in woodland, and in this case seven egg clusters were found on the bank of the Sabattus River. Thirteen egg clusters were found on trees along the roadside, east of the town. and two were located on another road near by. Each cf the remaining infestations at different points along the highway contained a single egg cluster or a pupal case. It is improbable that the infestations along these roads resulted from previous in- festations, although a few egg clusters may have been overlooked. Lisbon is located at least 70 miles from badly infested territory, so that bad woodland infestations were hardly to be expected. oe THE DISPERSION OF THE GIPSY MOTH. ce ry . 70° = ~ === = on 7s cs) = rn Ps ef i “A XFORD is \ Ses y O'S JyacksOn ag MARRI fh fr 6 = a. zfs » SON Gris- |AY > \ es r_\ \ x Qrorane Se x , " gt Wr, CR» BAC i at a F D f eae vind 0 |N : . hy pcb ritz- NULIAM SRIMPIELD | s nae eae hema #\%4 ra aa se d ors / = . conerhee i a a f : Jae Fic. 6.—Map showing towns and cities in New England where woodland scouting was done, 1911-12. (Original.) RECORD OF SCOUTING IN MILTON, N. H. ° 53 RECORD OF SCOUTING IN YARMOUTH, ME. - Scouting operations were commenced in Yarmouth, Me., on Octo- ber 23, 1911, by a crew of experienced scouts under the control of Mr. A. M. G. Soule. All the territory east of the Grand Trunk Railroad and south of the Maine Central Railroad, about 7 square miles, was examined. This section of the town of Yarmouth con- sists largely of cleared land and pastures. The wooded areas are in relatively small blocks, less than 3 square miles of the area being in woodland. The tree growth was rated by Mr. Soule as follows: Per cent. Per cent. SS SE) AM 6 6 Sen A At eS 8 11 2 eat cs WEESCO TT A ergs 28 sa Te a 9 ee ad It will be noted that nearly one-half of the trees in the area are oak; that conifers were 10 per cent less than in the district scouted in Lisbon; and that the area, although smaller, was more suited to rapid infestation, owing to the character of the tree growth. During the winter of 1910-11 15 infestations were found in the entire town, 7 of them being in the area under consideration. Ali of these places were along the highways or in orchards. Five of the - seven each had a single egg cluster, one had two clusters, and in the other a pupal case was secured. No egg clusters were found in these places this year, but a total of 27 infestations, containing 56 egg clusters, was discovered. Five of the colonies were in woodland, and in one of them 17 new clusters and 1 old one were found. Yarmouth is located nearer the badly infested area than Lisbon. and more woodland infestations should be expected than in the case of the latter town. _ RECORD OF SCOUTING IN MILTON, N. H. On October 25, 1911, a crew of experienced scouts under the direc- tion of William Sarsfield commenced the examination of the trees in Milton east of the Boston & Maine Railroad. This territory is hilly and the towns south and southwest of it are generally very badly infested. The area examined covered about 18 square miles, 13 of which are wooded. The forest growth was as follows, according to estimates furnished by Mr. Sarsfield: Per cent. Per cent. es ee gid a RE ee Ps 7 4 i D3 PA 5 a ne Ryda SRE, i 1G.) Miscellancoug:...o...-....... 5 ccniaperiblel, Ma » In the winter of 1910-11 the orchards in this area were scouted -and 21 infestations were found, practically all of which had a single egg cluster. In the whole town, the greater area of which is on the west side of the railroad, 159 egg clusters were found in 55 localities. 54 - THE DISPERSION OF THE GIPSY MOTH. In 1911-12 14 woodland infestations of 59 egg clusters and 22 orchard and roadside infestations of 202 clusters were found east of the railroad. The woodland infestations were in the territory between the Milton railroad station and the south end of the town. Jn the part of the town west of the railroad only the roadsides and orchards were examined, and 6,602 egg clusters were found in 57 localities. | The results of scouting in this town show that the infestation is increasing rapidly in both woodland and orchards. The figures for the two years are significant, for in the western part of the town the infested localities in one year more than doubled, and the number of egg clusters was more than 40 times greater than the previous year. RECORD OF SCOUTING IN TILTON, N. H. Examination of Tilton, N. H., was begun November 1, 1911, by Mr. C. E. Boardman and a crew of experienced scouts. The area of the town is about 10 square miles, less than one-third of this being wooded. According to Mr. Boardman’s estimates the tree growth is as follows: Per cent. Per cent. (GS TINGE YS iaaeia em BN TS Se eed Mi gtr eet sie 30) Him 2.) eee eee 2 OSV, SMe 7k ER A ge ate 2 13*| Birch <2.“ Se eee ee 12 531) 0) Ne Rae ae See Mal Sea cae Urano 35 | Miscellaneous_-_{__ 2) = ae 6 PAINE US Ber Bai) a 27 Sy ha 2 In 1910-11 the roadsides and orchards in the town were scouted, and four infestations containing 889 clusters were found. In one of these over 800 clusters were treated, and during the following summer over 4,800 caterpillars and pups were destroyed under burlap. As a result of the present scout only 11 egg clusters were found in three orchard and two woodland infestations, one of the latter being near the bad infestation of the previous year. This shows that good work was done in controlling and reducing the infestations found and that reinfestation by natural or artificial spread in this area has been slow. Tilton is located 20 miles north of Concord, N. H., wand most of the badly infested area lies to the southeast; some, hogs is near Concord and extends to the south. RECORD OF SCOUTING IN BENNINGTON, N. H. Bennington is located about 25 miles west of Manchester, N. H. The land in the eastern part of the town forms a part of the ~ watershed of the Merrimac and Contocook Rivers. Almost one-half of the area is wooded. An examination of this town was begun RECORD OF SCOUTING IN GARDNER, MASS. 55 ~ November 1, 1911, by scouts in charge of Mr. W. T. Kelly. The tree growth was rated by him as follows: Per cent. Per cent. ee og OB SS OE ee Te 2 ee PRAIPVRP OR ios eh oe SA lt 27 a 20. | Miscellgneous.____--___—______ as 10 Tn all about 5 square miles of woodland were scouted, and as the town is very hilly it was hoped that evidence of wind dispersion might be found on the high land. In the winter of 1910-11 the roadsides and orchards were ex- amined, and eight egg clusters were found in two localities. As a result of the present scouting no infestations were discovered in these places, but two new orchard colonies, one containing eight and the other three egg clusters, were found. No egg clusters were found in the woodland. Practically all of the badly infested territory lies to the east and south. RECORD OF SCOUTING IN GARDNER, MASS. On April 26, 1912, scouting in Gardner, Mass., was begun by Mr. F. W. Foster and a crew of experienced scouts working under the direction of Mr. H. N. Bean. A part of the woodland west of the Boston & Maine Railroad and north of the Fitchburg Railroad, covering almost 2,368 acres, was examined. Owing to the predomi- nence of coniferous and sprout growth two other areas were selected north and east of the town, where deciduous trees were abundant. Gardner is on the ridge of land which forms the watershed of the Connecticut and Merrimac Rivers and their tributaries, and on account of its elevation, about 1,300 feet above sea level, it was thought that evidence of wind spread of the larvee might be found. The examination showed, however, that the forest growth was not favorable for infestation. The season is considerably later in this locality than in the lower land near Boston. Gardner is a large chair-manufacturing center, and most of the hardwood has been cut off, presumably to be used for that purpose. The kinds of tree growth examined were rated by Mr. Foster as follows: Per cent. Per cent. EE NYO SS ee RS Se ea PE PS 3 SE CAN Ss EE ee ee pe 10 er 1 BAIBBeL tee et ne 5 Many orchards in this city are slightly infested, but no large col- onies have ever been found. The scouting work resulted in the dis- covery of only one infestation in woodland which was located far enough from orchard infestations so that the larve might have been 56 THE DISPERSION OF THE GIPSY MOTH. carried a considerable distance by the wind. The infestation men-. tioned was in a small block of woodland, mostly deciduous growth, which borders Crystal Lake, and is west of Woodland Avenue, and ~ in this place four new egg clusters were found. Another+infestation of a single egg cluster was on a maple tree 500 feet from the high- way, but there were two infested orchards within 1,000 feet, and it is probable that the spread came from these orchards. The cater- pulars may have been carried by the wind or on men or animals. A third infestation was found near the Winchendon line, but egg clusters had been previously discovered on several old apple trees in a pasture near the woodland. | Any of these colonies may have been brought about by wind spread, but the evidence is not strong. The unfavorable character of the trees would prevent, to a large degree, the establishment of the insect in woodland in this town. ; RECORD OF SCOUTING IN GRAFTON, MASS. On March 11, 1912 an examination of Grafton, Mass., was begun by scouts working under the direction of Mr. H. L. McIntyre. All the territory east of the Grafton & Upton Railway was examined, and a part of the woodland near Farnumsville was also scouted. The town is generally infested with the gipsy moth, and it is possible to find egg clusters in nearly every orchard.- The area examined cov- ered about 5 square miles of woodland. No orchards or estates were scouted. The different kinds of trees in the woodland were estimated as follows: Per cent. Per cent. GTS eres Re ts BE ht RO 6 | Chestnut. 220-0 Ss ee G1 sta SERN SAGs ieee ae Ca ambi. A/S DA AST See see a is ee at 113 | ah care ca, he eR Se ge a 20) 0 25 | Birch and beech@.._.22 22a 14 Org en eee 20 eae oh ae WR hah ee 1 | Miscellaneous ==) eee 16 As a result of the scouting the following infestations were located: One old egg cluster on a birch tree in woodland near North Grafton, two colonies on the land of the State insane hospital, one of 18 egg clusters near the barns, and the other of 25 egg clusters on a large oak tree on the edge of the woodland in the rear of one of the buildings. As there is quite a general infestation of the fruit trees on these grounds it is probable that these colonies were es- tablished by caterpillars carried on men or farm animals to the places where the egg clusters were found. An infestation of two clusters was located near the Westboro line in oak growth. Five infestations were found in two blocks of woodland on Esterbrook Avenue. In one block, where three colonies were found, four egg masses were discovered, three new and one old, while in the other RECORD OF SCOUTING IN WAREHAM, MASS. 57 block two colonies on low land totalled 149 new and 27 old egg masses. Most of the trees in these areas were pine, maple, and birch, with a few oaks and chestnuts. On the whole, these colonies were not very favorably situated for rapid increase of the species. One old egg cluster was found in woodland south of Grafton Center, and a colony of 20 nests was found on two apple trees in a block of woodland near Farnumsville. The discovery of old egg clusters is noted above, because it is probable that new clusters were present in obscure places on the tree or on the ground and were not observed by the scouts. During a part of the time several inches of snow covered the ground. In all the places mentioned it is probable that five infestations may have been brought about by wind spread, although this can not be stated with certainty owing to the state of infestation of the orchards in the town. Grafton was first found infested in the winter of 1908-9. It is located only 7 miles west of Hopkinton, where the gipsy moth was found in 1905. ‘RECORD OF SCOUTING IN WAREHAM, MASS. Scouting in Wareham was begun March 28, 1912. As it was im- possible to secure definite results by examining a section of the town en account of the prevalence of coniferous growth, several areas were selected, covering in all about 925 acres, and a scout of this territory was made. This area was used because hardwood growth predominated and, on the average, about 75 per cent of it was oak. As a result of the examination 112 egg clusters were discovered in eight localities. Two small infestations were found near the road leading from the Tremont station; another was in woodland near West Wareham, 50 egg clusters having been found. The white pine in this area had been cut, so that only deciduous trees remained. A short dis- tance away were located trees that had been infested for two or three years, and this may explain the source of this colony. A block of dead oak growth on high land near West Wareham contained two colonies, one of 50 and the other of 2 egg clusters. Apparently these were caused by wind spread, as there were no infested places near by, so far as could be ascertained. Three other colonies, of a single egg cluster each, were located. One was on the back road between Wareham and West Wareham. and the other two were southeast of the Wareham railroad station. Two of these may have been brought about by wind spread, but the third was near the site of a colony which had been treated for several years. 58 THE DISPERSION OF THE GIPSY MOTH. The result in Wareham indicates that there may have been some dispersion by the wind, but only a few of the colonies can be ac- counted for in tat way. RESULTS OF SCOUTING WOODLAND AREA. On the whole, the number of woodland infestations found is not so large as might be expected. Those at Milton, N. H., and Yar- mouth, Me., are the most striking, probably furnishing the most definite results of any of the towns under consideration. Owing to the long distance from Lisbon, Me., to the nearest badly infested area, which is about 70 miles, and to the large quantity of unfavor- able food for the caterpillars, it is not surprising that little evidence was secured to show that the infestations were caused by the wind. The other infestations in the town, however, indicate that there may have been a short-distance spread in this way. In Yarmouth, Me., the proportion of coniferous growth was practically the same as that in Milton, N. H., but the wooded area examined was only about one-fourth of that scouted in the latter town. Oak trees, however, predominate in the woodland in Yarmouth; hence it is not surprising that a larger number of colonies were found in that town than in Lisbon. More woodland colonies were found in Milton than in any other town, and this is what would naturally be expected, as 1t is near badly infested towns and is located so that the prevail- ing wind would convey large numbers of the small caterpillars. The woodland examined contained only about 13 per cent of oak. If this species had been as abundant in Milton as it was in Yarmouth far more serious infestations would probably have resulted. Scouting in Tilton indicates that good work was done in suppress- ing the gipsy moth during 1910 and 1911. The town is located a little out of the line of wind dispersion, and this, coupled with care- ful hand work, has evidently resulted in the satisfactory condition which has been reported. The results in Bennington, N. H., a town which is located on high land, where 21 per cent of the trees are oak, point strongly to the fact that the woodlands do not become infested rapidly when they are located in a region unfavorable for larval spread by the wind. Although about 5 square miles were examined in this town, no woodland infestation was found; and when it is remembered that this area is less than 10 miles from towns which were found infested in 1908 and 1909, the evidence is further strengthened. The danger of artificial spread of gipsy-moth caterpillars on vehicles is probably less in this town than in any of the towns where woodland areas have been scouted. The scouting in Gardner and Wareham, Mass., was handicapped by the fact that the woodland growth was not satisfactory for the RESULTS OF SCOUTING WOODLAND AREA. 59 establishment of the species, although the selection of areas contain- ing the most deciduous growth in both towns aided in securing more satisfactory data. Wareham was found infested in 1905, and if the town had been located along the line of prevailing winds at the time the gipsy-moth caterpillars were in the first stage, the woodlands would probably be as badly infested as those in towns an equal distance north or north- east of the original infested area. This is not the case, however, which indicates in itself that unfavorable food and practical im- munity from winds favorable for spread have worked to the advan- tage of this town. The same statement can be made of both Gardner and Grafton, which were found infested in the winter of 1907-8. It is true that there are a considerable number of small roadside and orchard infes- tations in these towns, particularly in Grafton, but travel is heavy during the early summer and an excellent opportunity is offered for the spread of the larve on vehicles and automobiles. If wind spread were not a prime factor in distributing the gipsy moth, the woodland in Grafton should be more heavily infested than the wooded area examined in Milton, N. H., because the latter town is much farther from the original center of infestation, and was first found infested a year later. It is practically impossible to explain the origin of many separate infestations; but taking the woodland areas examined and studying them in relation to each other and in relation to the badly infested area, it is evident that the theory already given concerning wind spread is confirmed. | It is surprising, when all the facts are considered, that so much good work has been done in controlling the gipsy moth in many of the infested towns. Large numbers of cases are on record where all the infestations in a town have practically been cleared of this insect in a single year; but, owing to general wind spread, as many and usually more colonies have been found in other parts of the same town the next year. This is one of the discouraging features of the work and renders it extremely difficult to control the insect in towns which are most subject to natural spread by the wind. It is obvious that if this is to be brought about, bad colonies must be subdued, particularly those which are nearest the outside border of infestation, because, as has already been pointed out, the farther the larvee are carried by the wind the less the chance becomes for them to establish the species, owing to their wide separation from other speci- mens and the limited opportunity of their finding suitable food for full development. 60 THE DISPERSION OF THE GIPSY MOTH. EFFECT OF WIND SPREAD ON THE PROBLEM OF GIPSY-MOTH CONTROL. . The fact that gipsy-moth caterpillars are spread chiefly by wind during the time they are in the first stage and that for this reason the present spread of the insect is toward the northeast, northwest, and north has been sufficiently demonstrated. Another factor which enters into the problem to a greater or less extent, and which has an important bearing on the spread of young caterpillars by air cur- rents, is the altitude of the woodland in the various towns. Whether high altitudes are more likely to become infested in this way than low areas it is difficult to state, but there can be no question in regard to the difference in temperature of winds after having passed over an area of high land. For example, the cold winds which sweep down the New England coast. from the northeast and east are not accompanied by as low temperature, nor are such winds as cold or penetrating in the central part of Massachusett§ as they are along’ the seacoast. As high winds must be accompanied by high tempera- ture in order to bring about the spread of young caterpillars, it can be stated that after the territory on the west side of the watershed in Massachusetts and New Hampshire becomes infested to such a degree that large areas are defoliated, the spread of the young caterpillars by wind will be more far-reaching and more rapid than it has been at any period since the moth first became established. It is indeed a fortunate thing that the gipsy moth first found lodgment on the North Atlantic seaboard, on account of the various elements which have worked together to restrict its spread. If the insect had first escaped in central Massachusetts, in Connecticut, or in New York State there would have been ample opportunity for spread in all directions, and it would have been difficult to restrict it to anything hike the area which it now occupies. SUMMARY. The gipsy moth is spread by local and long-distance means. Local spread may be due to the transportation of caterpillars or egg clusters on carriages or wagons that move for only a short dis- tance outside the infested territory. The egg clusters may be carried on driftwood which floats down rivers during the spring. Long-distance spread may be due to the shipment of egg clusters on lumber products, nursery stock, or boxes from the infested territory to any points where such goods are unloaded. Caterpillars may be, and often are, carried long distances on automobiles or trolley cars, and cases are on record where colonies have been established in this way. RECOMMENDATIONS. 61 By far the greatest dispersion is due to the fact that first-stage eaterpillars are blown by the wind. A glance at the present infested territory shows that dispersion has been along the line of the prevail- ing winds immediately following the hatching of the caterpillars. One condition favoring wind spread is the presence of large woodland colonies which are overpopulated with caterpillars. This stimulates activity on the part of the insects in search of food and affords oppor- tunities for them to be carried away by the wind. High temperature increases the activity of the caterpillars, and this tends to increase the chances of their being blown away. Weather records for the past 10 years show that the prevailing winds during April and May, when the temperature is high enough to make the caterpillars sufficiently active, and when the wind is strong enough to blow them for any great distance, are for the most part from the south and southwest. The character of the food has a very important bearing on the dispersion of this insect, because unless caterpillars that are blown by the wind are able to find lodgment on favorable plants they will not survive, and there will be no opportunity for the species to become established. If a number of first-stage caterpillars were dropped by the wind into a forest of solid pine they would not be able to establish a colony, because these small caterpillars can not survive on pine foliage. There are other trees, particularly conifers, which are equally immune from injury by the first-stage caterpillars, and upon which they are not able to develop. This shows that large blocks of unfavorable food plants will not only prevent the establishment of the insect, but that such woodland will require no treatment what- ever, provided it is isolated by removing the favored food plants near by. RECOMMENDATIONS. As a result of the experiments which have been conducted and a study of the data which have been secured, the following recommenda- tions are made, as these have a practical bearing on the gipsy-moth problem : (1) National legislation should be enacted to provide for the inspection of lumber products or other material which is likely to earry the gipsy moth from the territory which is now infested to uninfested regions. This is particularly important and is distinctly of national concern, because goods of this sort are often shipped to far distant points in the United States, and without careful scrutiny excellent opportunities are offered for establishing new colonies remote from the area in New England which is now infested. (2) Inasmuch as certain coniferous trees, if grown in solid stands, will not furnish favorable food for small gipsy-moth caterpillars that might be distributed by wind spread, and as some of our decidu- 62 THE DISPERSION OF THE GIPSY MOTH. ous trees will probably furnish similar unfavorable food conditions, it seems very important to determine by careful experiment the sus- ceptibility to gipsy-moth attack of the various species of native trees in New England forests and to test different methods of thinning woodlands in order to reduce the infestation by furnishing unfavor- able food, and by so doing to prevent the area thus treated from becoming so badly infested as to enable caterpillars to be spread from it by the wind. These experiments are now under way. (3) The experiments conducted indicate that little spread by the wind will result unless badly infested areas exist. Inasmuch as the principal spread over a wide area is due to the wind, more attention should be paid to the proper handling of bad woodland colonies along the lines already indicated, in order to prevent widespread distribution. From the experiments conducted, and from the data examined, and as a result of interviews and conversation with various officials and parties interested in moth work, it appears that the spread of the gipsy moth at the present time by automobiles or other traffic is far less serious than heretofore. Already a large mileage of trees along trunk roads has been thinned and protected, so that the danger has been largely reduced in this way. Special attention has been given to many roads leading to and from summer resorts or camping places where automobile traffic is heavy during the summer, and as a result of this work and of the scouting which has been carried on in the outlying territory, which included an examination of the trees along many of the trunk roads in unin- fested sections of the State as well as an inspection of places, such as hotel grounds, where touring parties would be likely to stop, it has become quite evident that in the last year or so the danger of infestation by means of automobiles has been greatly reduced. This would indicate the desirability of reducing the thinning operations along roadways, except on those where the automobile traffic is the heaviest during May and June. (4) The work which has to do with the determination of the limits of spread of the insect, and which is known as the scouting, is of great importance. This is being carried on in the outside in- fested towns and in those adjoining, and too much stress can not be laid on its thorough prosecution. The men actively engaged in it- should be instructed thoroughly in regard to the best methods of thinning woodland in order to control the moth, so that practical advice can be given to the owners of forest land to stimulate them to take proper measures for protecting their property before the infes- tation becomes serious enough to cause severe injury. O Be RR et a Boe a — © ss tty = Regs ' i. | q Dane, , ; ¢ ; P > a y A pe « 1) . ? , { “ all ap , ‘ Fe De \ of nih abe abated hens AMAR AYA; Annan’ PN ry] YON | 7% ~ 1. W - rN] “ wr ve ~ : iA | 7 , - / \ oY = j f rN j 4 \ y ‘ ’ ; | y a 2 ; j a F ~ = ~Le ’ Df é : , 7 ~ VW VAat. ; : j | 1 i ; { ; 1 { | 7 j ; 1 f 4 3 | Ke 7 ; F i | ) Ton | f 1 } 24 .. H A f 1 1 _ ry ‘ r * r 2 ¥ 1 / | x 3 r * > ¥ > i ; : 4 = ’ I : aTy j 4 - } | ~ ; , : f ’ 7 . j ; Sie WARAA nna ieee | ae my | | fy TY] 7 | : ~A\ah { iy f | 2 . Mtns Pa alison | ae. .adAAraaa aia oy v7 Y ae pp coil il Awa ‘aaa lem | AA a tna one eee cae ern euaee sate acallinsas aM \ ia one 4 alt -_ / a lalalal \ AR AAR aah“ Aa ahi Vale’ Jaleo peal WY. 2)», >a » 2 Ww» » D2 » OA" THA ~ g 4 , ~ “antanaest AMAA ~ ~ i ' ae wy RA - <3 vA 4 AM Bw on. fy ‘a : a yi . | | | | AA AA Aa Onn Man AAA, ARMADA ARR on . om, P “+ ayer . ~ s ~'5 WAR AR RRR RRR / / fe al, > a TY. YAR y ’ a ano ee A ~, wand Ms A MULL 3 9088 01267 7662