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Ty ay bye Beye wih Soya Vee an | ee ta uryy a aa om ws weet sca untae rene MAM wheres ws Now tes cece RAAT eo “95 be Fe) Suv es ¥ . eS ie US's ’ Nps ei | 04% bd toe use wis peas ahi TS a siddy Med were yy Pyeee seks ee aN casas 1h ee. Sie ot DOGGIE HI We ded De et tees = bee” a ted Bid RAAT Vite ge we le 4 New 2 Nese" aubaienpe OTe sees tell ohn aN ec e CTI Igy ee | ww d > | @ Vf Vyvew, ge" id 4 Nee w YN yd A vi ww wi Vow * y Ort AST ye" day shal ae NE ES A ¥ oes TRA We, sae Sia _ Pe: sad doh we ‘ ai aie ds my ~ oy id ay ye © dye de savyliwersrerro: oo se eyes “lle NOT cul eee Or ay OL hav eae peur ree eee Sees! EW ek 35 AE PAO ed in vd? ¥ eyctrewerrery Wea DESI Mo ees eee. ef Weed eer = a AAA PAE ALE FA IAA cee 1 Bee eo” Widwew! coulec~ weet! ete TREE REEMA LEI kt te Een meeUw aioe revue tele "onviVOYhy ty vba | oo ~ 2s we a ok ae ae ‘ t= hi 5S GS52 5082 PRR Tah dare hk x Weveiytirvet ren. A Mee le ee vei : Cel erey ee : met cai pipiens Se ine PE ee ee ste at sila mm ie wi isuialift wee TD vy ae ss ony Wi Seoflu se; ~* “oad a oow* wi vom Ha AA iets Ptah we OMY: . : cy ey, J Ue ‘ wry? Manes 3 yoy A Sees, ¥ 22 : = Bas 1) fe e YET : Hp bt ae et hhh \ ed A do elowerercl ai we 4 me: pee dD ke od ah ew yaeu sew ~" ie . oot ey ee Cue wv af ob it ieee Lean ‘yer’ glover sty / ne eae clleeeee oie te J w \ 1 pal — " : areal a nt Be Hb Wy Weve ec TI OCT Rg the Tey = op uo “Nig "a ef wee we syst rye? soy yreew™” % vw wwivs = Woywewvyee 4 vey ve isee: os akel-f oa. esccecepeccun wree rs R Ueiceteee curt ce weit tt Viwcvwrele sete crane wig | yyw We erie ww v a ”) wre" KS : Ny e oki aes v n'y Madde ve wv ; ~ wR ey we AAs . , - L a9 or) -\ wy Bese gesae IAAI , a th gh ee KAS A} hy ‘Ww de ‘al ant toddded | v vw Vu tie i ng Jw WY oh 4 uv? wie Ven rie Entomologist. \ yr A” " PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST « BY « v ul 0, B. SIMPSON, nian lity ta AE Mi i ~ * pee] iy ™~ Ney ED Loss ni ae SUNY obey ety N - > Spacran Frsup AGENT. / WASHINGTON: — ERNMENT PRINTING OFFICE, UBT coe. 60)” wacemta npg i critica tage Soles eee aS = 6234 ees i Hl agg tga Bul.41, New Series, Div.of Entomology, U.S. Dep PLATE |. Upper Austral Lower Austral Gulf Strip of Lower Austral Se Ban: Tropical s of the dustral Zones east wrdicate the extent of the of these Zones, krown respec- JULIUS BIEN A COL THNY Corrected to December, 1897. ee . DEPARTMENT ereaGRIiCULTURE. DIVISION OF ENTOMOLOGY—BULLETIN NO. 41. L. O. HOWARD, Entomologist. me CODLING MOTH. PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST BY Cl Ba SIM PSOoOn ; SPECIAL FIELD AGENT. yy eS (/ ie ioe WASHINGTON: GOVERNMENT PRINTING OFFICE. 1903. PLATE 1. | U.S. Deptof Agriculture. Bul.41. New Series, Div.of Entomology, 130° wea am eh TO eee aes Transition Upper Austral eal Lower Austral pe oe Gulf Strip of Lower Austral cea Tropical 2% | The dotted parts of the Austral Zones cast of the Great Plains indicate the extent of the humid divisions of these Zones, known respec- avely as the Aleghaniar,Carotiniar and Aas- wortpartan Faunas. Theundotted parts of the same lones are known as the Transition, Upper Sonoran and Lower Sonoran . JULIUS BIEN & CO. TH NY Corrected to December, 1897. LIFE ZONES OF THE UNITED STATES BY Cc. HART MERRIAM ° 8 ey x ae * “6 a ere | AR ey a j ih is ie = DIVISION OF ENTOMOLOGY. L. O. Howarp, Entomologist. C. L. Maruart, in charge of experimental field work. F. H. Currrenpen, in charge of breeding experiments. A. D. Hopxrys, in charge of forest insect investigations. Frank Benton, in charge of apiculture. W. D. Hunter, in charge of cotton-boll weevil investigations. D. W. Coquitietr, TH. PERGANDE, NATHAN Banks, Assistant Entomologists. E. A. Scuwarz, E. 8S. G. Trrus, Investigators. Miss H. A. Ketuy, Special agent in silk investigations. R. S. Currton, F. C. Pratr, August Buscx, Orro Hrrmpemann, A. N. CaupdE.t., J. Kormsky, H. G. Barser, Assistants. W. E. Hinps, W. F. Fiske, A. L. Quarntance, G. H. Harris, H. E. Burke, A. W. Morriuy, Temporary field agents. 2 “= | LETTER OF TRANSMITTAL. U.S. DEPARTMENT OF AGRICULTURE, Division oF ENTOMOLOGY, Washington, D. C., July 29, 1903. Str: I transmit herewith the manuscript of a report on the codling moth, prepared under my direction by Mr. C. B. Simpson, field agent of this Division. Mr. Simpson had been charged with a special inves- tigation of the codling moth, more particularly in the Northwest, in answer to special requests for such study in the newly developing fruit interests of that region. The codling moth is undoubtedly the most important insect pest of apple and pear, and is the occasion of greater loss than all the other insect enemies of these fruits com- bined, entailing an annual shrinkage of values exceeding $11,000,000. Mr. Simpson’s investigations covered a period exceeding two years, and have already been voiced in a small preliminary bulletin and in a Farmers’ Bulletin giving condensed advice relative to the control of this insect. The present publication is the final and complete report, elaborating all of the conclusions and results of this special investiga- tion. It will be a very useful document for all workers in applied entomology and of decided practical value for the fruit grower. The illustrations which accompany it are essential to the correct understanding of the experiments reported and of the text. J recom- mend that this report be published as Bulletin No. 41 of the Division of Entomology. As stated in the letter of transmittal of bulletin No. 40, the term ‘‘ New Series” has been dropped. Respectfully, L. O. Howarp, Entomologist. Hon. JAMES WILSON, Secretary of Agriculture. CON TENTS: 4 EMD PIS NT TS aes oe So i a Nr Sg ar SR Tee SHSNS IMA JOOSNINNONN SRS Sa Sa ee Ce es ee eae See ee ee eee a NEIMeSTO le TNSCCipare mete Sasa o- Sam Nee Set oes ee ome eT at ae era RRL nncen eee ages oe md A ee en Cre tes ce oe oe gta SG Mill Gene Cx mreer rere seers ke Dp aen ene me Sins PM ahs Sie eee Seimnicweneiinercmmir® MON 5) Jona ka ttre eae anit So. 2S So se ee Peerage icon SC IGuell UL UOM +o. f oS stk od baa e 2k eta s Avi adeeeie Seen: vee Sa Relation of distribution to life zones..--...-..-- distort cd aah ae aor meneame tte epiiete UnbrL Ness Se ati a weean eos. ans koe eee oe See vavky PME te Maistre AOS. Fnac. eee Sete t oA enh boca n artes Cee ee be eke oe eats ie T se eran oss cee (ern ea ee Oe oe Cd Beatie aes oooh uk CEIEOT BE ke | copes ee eg eae es peel oO Ree seine ap EDN rs Pannen ON en eee BEE BO sone al Abe aaitse 28a Sa Loe aro S Nex na Ab ee icioas ia SL eee Nee Meee Satya nS aot em Kea gL a Sw are an kite MSL Le oe De eect NILStes Peas tae) pO te eran os 5c Re dee ee et oc GS ema ininco Mn tee = 2s cos shoe Sees aa 2 salen eat Faw e ok Gk seme ee PEUiieve MLO Geren ine pasos Ye Saeco oe a hen pe ae eee eet ee NAGLE RET OUI SS SUL C1) C2 eae & ae Og he Ley a ae CS ea A RRL DRE re TEER SEES IOS Ses See Sage OE Teas ee REL See Ns SNe cegugl ot nee as eee Wate Wa Ee aS ee ee a eee saat bes te Pe eeRewnener lisraa meet 22 ne pee ee aa econ oes eee ese NVitemaimeteemtaeOsatd: oS Ne ee Soe Sls Uo oiiacai oot wagon The number of eggs. laid by one female-._-.-.2.2-.2-5-.2-..-s++---- ee avin POrMlOG sa & oars eee lasts aes. Sete eae Lou n ceeket os Meanie Wwern BIROGS yao M hers ok. aoe eh cies ae ee MEE aeie we e teeee on i lestiee te MVC) Pablne BOO Were. Lone Cesk eu ward etc ete BES Buh os eee wae Dheanecsco tna MCU WON <2 55-6 2S apc s caeek ee Se lL Gesck tak Methous emi aminererid o> oe ed a ie a eee Influence of temperature upon the length of the egg stage_..-....--- CIN Do] SS 2 oe 2G A etsy oo eg ea eo Se ae Re Merenpimem of jublsorown: lanes 20 5 28a es os, wc snc pe ene LIST” DAD LERE WI 2 Sh (OI age ke eg Re eS ea eee RE GEN sGeeMiPAM CR or cou Rh. oS Doe ea Sy oe eee oe AMM ear Peas TNUNE NEON. es eee AS Ok eek alas oe SL SS Preparawons tor leaving the fruits 0.5. o.c02. 0 2 ete. oe ee ues DER COM CGU TESTS a U1t] gir ie ame O Ee ie on tee Dee ee a oe a a oO Pei mp UN INP COCOONS nu ate ore Sie Sos ec 2c. ek ee ec orapiien onetiae COCOOM, Stages em eho cs ea eo Jak ee LS Life history—Continued. Page. The larval stage—Continued. Duration of the staves the cocoon mes=nss-eese ee see ee 37 Influence of temperature upon the duration of the stage.--....------ 38 Hitect of theinsect upon the atriiites <2. = sae eee ee ee 3 he pupa iss 222s ei ee Sees Se ee eee eee cea 39 Bmercence:of the mothe s22 se See as ee eae eee ee 3 Pieiadultimsechsaceg Sashes Cee ee a 40 Howstordistinetish the sexes] =) 55 s2= eee ee ee 40 Habits of the moths iat: 22 Sines See eee eet Sok oe 4] Duration -ofjite ‘ofthe moth 4522 2282. eee ee 4] Generationsiobtihe ansects << S55 so St eee ase ae a 41 Seasonal history. 2.02 hie ie Rai eee ee ene ee ene ae ee 50 Enmiergence of the mothi: 1.5.28 2 2 ee eee vee ue a ee ee 50 Relation between the emergence of the moth and the blooming period- -- 51 Eibernahlonrets: 2 e238 ote 5a ee ete eee ee eo en eee 54 Byvidences ofa thindsgeneravion == 2. ae eee epee eee er ee 55 Conelosion te. Sooo 0e Shc ae eee aoe eee epee eats ete Seis eee 56 Natural conditions which tend to decrease numbers. --...--.---------------- 57 Natural enemies. _----------- a ae Ny EOS UR gi age OR ee 57 Invertebratesenemies:s. 3222/0 222o so eeasae olsen 59 How:to-combat the insect 32225 soe oot ene 2 aye eee ee ee 60 Preventive measures sas. S525 5s os oS ee ee 60 Netting the trees says esos cet Se Se ee ene eee 62 | Sb oh ey ene etry aaa Ma er a ean eae rae re em ate deren ice =) Fe 63 Lrrivaiione: oo yess Sa eos he VISE oa oe tee 64 Soilomico yer Crops eis eee toe ee = eee 64 Orehardcine bearing <3 0c Su en tae 2 Sr eet neice een 64 Preparme-truitstorthermarke ta as ee = ee eo ee ee 65 Preventive measures in’ old-orchards:..- 222225 5.2 22 S22 9ee eee 67 Treatment of olds orchardsiste. Ass tee oe ee et ea eee 68 Remedialamcasures =. 25.2 Sass Ss ass se a ee a ee lap 69 Measures of little or no-value 22 >: 2 So 2 Peet rae Ss) 69 Mieasures‘ofsvalue 2 2)23 2 Sein ee oe ee Oe ee 72 Measures vised: against the tar veces oe 72 Materials:ior sprayimg: S232 2 seta see 3 ee ee 80 Cost of sptayihee. os. oo aie ae ee EO eae a See 83 Time and frequency of application of spray .-..----.--------------- 85 How -the:poisom killsthe insetts>s7s 522) 355 Ss a oe 86 ‘Nhe sbanchiness ys te mnt es es Ae eee ae eae ee ca spa Se eet Pa 88 Hixpense ot- banding: 28252568 20 i aac see ny 91 Wihen bands amaybewsedian 2s se sae ee epee Sar ee ert hes ete 92 erarett Gall teste sors 2 ey eee ee Noy Sh ay a ne 92 RESIN Ali (Come lUSTOMs yess f ana se ee eee Sere Re eee se eee es alr eee 96 Bibliography of the more important contributions to the literature of the cod- limes Oth':.ss.c25 sce eck tes ee oe eae oe ere ere 97 Pebist RAT TONS. PLATES. Page Praret., dite zones of the United States = .- 2. 22-22. 2.5.) 2d. 2s eeee Frontispiece. II. Fig. 1.—Apple leaf inhabited by codling-moth larva. Fig. 2.—Apples damaged by caterpular =o: 25a. Se ie Ther OA Se Sg ee 16 iieeh iors Gitihercomline tm Othe as a ee ae No ee ee 16 IV. Fig. 1.—Entrance holes of larvee of second generation. Figs. 2 and 3.— Views in orchard of Hon. Edgar Wilson ._.......-.-..------ 32 V. Fig. 1.—Codling moth larva, enlarged about three times. Fig. 2.— The ‘‘worm hole’’ or exit hole of the apple worm (enlarged). Fig. 3.—A wormy apple, showing the familiar mass of brown par- ticles thrown out at the blossom end by the young larva (from SUT SS ol LER EPL) gk ee ge Re Maen er a nS OS ee 32 VI. Fig. 1.—Laryee, pupze, and moths on rough bark. Fig. 2.—Infested aopies beme puried:. 22.3.2 5500. 2-2. tect ase Se ewes ae 48 VIi. Fig. 1.—Codling moth enlarged four times. Fig. 2.—Codling moths enlarged twice. Fig. 3.—Codling moths, natural size.....--.-.--- 48 VIII. Stubs of branches trom an old orchard near Elkton, Md., showing work of codling-moth larvee and woodpeckers -............------ 64 IX. View in orchard of Hon. Fremont Wood, near Boise, Idaho ..__--- 64 X. Fig. 1.—Band on which the remains of 380 cocoons were counted. _ Fig. 2.—Pupa in cocoon on underside of a loose piece of bark. Fig. 3.—Laryva and pupz in cracks in bark from which rough bark [IPE SOL reel ope cy a01 0c 6 Ee RRM ae Mi i fe ARON pate ge ORE RID San POA DSR ar 80 ol. Gasoline pawer spraying. machines. 55.63 As oe ly ek 80 Bell sprayier OuLute ir tne G2 ek a eit a eo sk eee 80 XIII. Clean and wormy apples from tree No. 2, Wilson orchard ....-.-.-- 96 XIV. Clean and wormy apples from tree No. 4, Wilson orchard ......---- 96 XV. Clean and wormy apples from tree No. 6, Wilson orchard __...----- 96 XVI. Preparing apples for market, orchard of Hon. Fremont Wood, Boise, TG \SW AYO Ss SBS SS o_o ote re eg lies Sea at area eens rc CPE at 8 sae Rep 96 TEXT FIGURES. Pt eee een Mimetiel bea Se Se Su nce s ceo oo on eno a kel 2 21 Pomel tiaviiienpumMehelinieer sates oor. SSE Lio een SLs woe 22 Seen emVenAMNere Neral io ne Sees Soden Suk ee es 5 Sree es 22 Are CHO MLOtN Ser TizOnelly 252i so 2 25ol aso. aS. tel Seeks oa bse 23 5. Daily band record made by H. G. Gibson, Nampa, Idaho, in 1901, TP Oe a see ame jee ee ene Saki te) Sen te Mees aes certs, Oe Sees a 46 6. Weekly summary of Mr. Gibson’s band record...........----..--+- 47 7. Band record made by William A. George, Caldwell, Idaho, in 1901- 47 8. Weekly band record made by Mr. Ayres at Boise, Idaho, in 1897, CI UR Re Cc pee enn eee ee women ee ST ee oo - . 48 Fic. .. Band-record. made by Mr. Ayres in-18982s-2 32 oe ace oe . Band record made by David Brothers in Colorado in 1oJu-....------ . Band record published by Prof. C. P. Gillette, taken on 14 trees, at Rort:Collins,-Colo.,- ina 900): so. sees se eae ear eee . Band record taken by Prof. E. A. Popenoe, Manhattan, Kans., in WS89Os 2o.5% ot Se asked Sad cee eS SS ae Si Be See eee ere 3. Band record made by Chapin on 850 trees in San Jose, Cal --...-.-- Band record by Prof. J. M. Aldrich, Juliaetta, Idaho, on 40 trees, Lc} | 9 ne ae BERR eee Rien a trifie ys ek ORR TTY a Ne IY oO en ie i Sei One of the records made by H. E. Burke, at Boise, Idaho, in 1902, to determine the maximum of the second generation. .....---------- . Record by H. C. Close, Utah Agricultural College.........-.--...-- : Spraying outfit for treatiniettall trees. ee eee . Large apple tree properly banded for the codling moth (original) -- - . Apple tree banded, showing bands both aboye and below a hole in the tree sais ee ee eee ee oe te Page. 48 49 Poe IN, MOTE. (Carpocapsa pomonella Linn.) INTRODUCTION. ee Every person is acquainted with ‘‘wormy apples,” and many have seen the caterpillars in the fruit, while few know the history of the worm-like creature which causes the injury, or whence it comes or whither it goes. If apple insects were classified in the order of the degree and extent to which they cause monetary loss, the codling moth would rank first, since it causes more injury than all other insect enemies of this fruit combined. It is the most serious drawback with which the apple grower has to contend, as from one-fourth to one-half of the apple crop of the United States is injured every year. The control of this pest, how- ever, is not difficult when compared with that of many other insects, and hosts of apple growers are each year saving practically all of their crop from its ravages. In the literature of the subject, one finds that Cato makes the first mention of this insect, and since that time almost every entomologist has studied it and written about it. By the writings of LeBaron, Walsh, Riley, Cook, Goff, Forbes, Howard, Slingerland, ‘and many others, information about its life history and remedial measures has been disseminated, which have facilitated its control in the eastern part of the United States. It was found that in the western United States the conditions were different from those in the East and that the recommendations which brought success in the East did not give satisfactory results in the West, and the necessity arose of making a close study of the western conditions. Among those who have written on the insect in the West are Messrs. Washburn, Koebele, Card, Aldrich, Gillette, Cordley, and Cooley. . The two principal accounts of this insect are those by Dr. L. O. Howard in 1888 and Prof. M. V. Slingerland in 1898. Both of these writings give a summary of what was known of the insect at those dates, with many original observations and suggestions for its control. 9 10 Slingerland’s bulletin is especially comprehensive, partly because of the late date of its publication, and partly because a complete bibliog- raphy and valuable historical notes are given. The excellent observa- tions and photographs are important features of this publication, which has been of the greatest assistance to the writer of this bulletin. The writer is under obligation to many for the aid given in this work. Hon. Edgar Wilson, Hon. Fremont Wood, and Mr. W. F. Cash rendered assistance in carrying out the practical tests; Mr. Alex. McPherson, the State horticultural inspector, made observations and gave aid in many ways; Mr. 8. M. Blandford, of the United States Weather Bureau, at Boise, kindly furnished the tenaperature data used; Mr. H. E. Burke, of the Department of Agriculture, assisted in the work in 1902, and did much valuable and accurate work upon the life. history of the insect; Prof. C. P. Gillette and Mr. D. W. Coquillett kindly gave the writer access to their notes. Many fruit growers in Idaho have rendered especially valuable aid in keeping records. Pro- fessor Slingerland granted permission to use many of his figures, and his bibliography, with his notes, is used as a foundation for that por- tion of this bulletin. Prof. J. M. Aldrich, Prof. A. B. Cordley, and Prof. C. V. Piper have at all times given aid, counsel, and advice, and granted permission to use their unpublished data. The estimates of injuries inflicted by the codling moth given in this bulletin are based principally upon observations made upon check trees in spraying experiments. ; SYSTEMATIC POSITION. The codling moth belongs to the order Lepidoptera, or scale-bear- ing insects, and has been assigned to the family Tortricide. The description of the genus Carpocapsa Treitschke, as given by Meyrick, ts as follows: Antenne in ¢ simple. Palpi moderate, curved, ascending. Thorax smooth. Forewings with termen slightly sinuate. Hindwings in ¢ with longitudinal groove below cell, including a hair pencil; 3 and 4 connate or stalked, 5 nearly parallel to 4, 6 and 7 closely approximated toward base. A small but rather widely distributed FECeYOUISTS espe Ra The species pomonella is distinguished from the other species by having the margin of the ocellus (or black spot on the wing) of a coppery metallic color. (See Pl. VII.) The description of pomonella is given by Meyrick as follows: °14-19mm. Forewings dark fuscous, finely irrorated with whitish, with darker strize; basal patch sometimes darker; a large dark coppery brown terminal patch hardly reaching costa, anterior edge more blackish, ocellos within this edged with bright coppery metallic. Hindwings fuscous, darker terminally. 11 . NAMES OF THE INSECT. POPULAR NAMES. The name ‘“‘codling moth” is the one most generally used by the American fruit growers. The first name given to this insect was ‘‘near eater,” on account of its feeding in pears. Later writers called it the ‘‘apple and pear worm or moth,” ‘‘ fruit worm,” ‘‘ fruit moth,” and many others names. The name ‘‘apple worm” is often used, especially by the English. Wilkes, an English author, first used the name in 1747, which name was taken from a kind of apple tree. Slingerlatid says that the word ‘*codling” is doubtless a corruption of the old English word ‘* querd- lying,” which means any immature or half-grown apple. Some hor- ticulturists and entomologists and-others use the names ‘‘ coddling” or ‘‘codlin.” Asa result of extended research Slingerland discards these names and gives the name ‘‘codling” decided preference. SCIENTIFIC NAMES. In 1758 Linneus gave this insect the specific name of pomonel/a and the discription is as foilows: ‘‘Alis nebulosis postice macula rubra aurea.” Schiffermiilier, 1776, named it ‘‘pomonana.” Fabricius, 1793, gave it the name ‘‘pomona.” By reason of the eighteen years priority the name ‘‘ pomonella” stands. Linneus gave this insect the generic name of Z/nea. Later it was known as Pyralis, Tortriv, Semasia, and EHrminea. Still later it was given the name Carpocapsa, which was in use for about three-quarters ofacentury. In1897 Walsingham concluded that the name Carpocapsa must fall and be replaced by Cydia. This view was adopted by Fernald in Dyar’s list of North American Lepidoptera; but Cockerell strongly doubted this conclusion. After a very exhaustive study ef the sub- ject Mr. Busck concludes that the old name Carpocapsa is the proper name and must be restored, and his conclusions are accepted in this publication. VARIETIES OF CODLING MOTH. Staudinger described a variety of the codling moth which was bred from either apple or walnut in which the coppery spots in the ocellus were more broken and gave it the name of putamnana. It has evidently been thought for many years that there was a variety of the codling moth in the far west. Matthew Cooke said in 1883: ‘‘ From investigation it is probable that there are more than one species of codling moth infesting the fruit of this State [California], but I am not prepared to report at the present writing.” In 1900 the writer found one buft-colored moth which, except for color, was like the common codling moth, on the trunk of a tree at 12 Boise, Idaho. During 1901 four well-preserved specimens and eight badly worn specimens were secured. In 1902 six of these buff-colored moths were bred among 182 normal moths. In material collected in Idaho in the fall of 1902, from which about 30 moths emerged the following spring, five were of this variety. Mr. A. F. Hitt, of Weiser, Idaho, and Mr. Alex. McPherson, tell the writer that they have noticed these buff-coiored moths. Mr. Hitt, in 1896, bred seven of these among 50 normal moths. _- The writer submitted the moths to Mr. August Busck, of the United States Department of Agriculture, for determination, and in the Proceedings of the Entomological Society of Washington he describes them as follows: These specimens were submitted to the writer for determination, and I have care- fully examinedt hem structurally in comparison with the common form of Cydia (@) pomonella Linné. Ido not think there can be any doubt about their being this species; the oral parts, the venation, the secondary male sexual character of the hind wing, and the external sexual organs of both sexes are identically as found in the common dark form of the codling moth. The general pattern of ornamentation is also the same, but the coloration is so strikingly different that the variety deserves a special name, the more so as no intermediate forms seem to occur. I propose that it be known as Cydia (') pomonella Linné, var. simpsonii. Instead of the dark fuscous color of the common form, the variety is light buff, with slightly darker buff transverse striation. In the common form the forewings are finely irrorated with white, each scale being slightly white tipped; in simpsonii the scales are not white tipped. The terminal patch, which in the common form is dark coppery brown, nearly black, and with dark violaceous metallic streaks, is in simpsonii light fawn brown with pure golden metallic streaks. The extreme apical edge before the cilia is in the common form black, in the variety reddish brown, and the cilia in simpsonii are light golden ocherous instead of the dark fuscous of the common form. The head, palpi, body, legs, and the tuft of hairs on the hind wings of the male are correspondingly light-buff colored in the variety instead of dark fuscous, as in the common form. Besides Mr. Simpson’s specimens, in which both sexes are equally represented, there is in the United States National Museum a single female, labeled ‘‘ Cook, Cali- fornia, July 30, 1883.” Type: No. 6803, United States National Museum. The writer has never observed any gradations between this variety and the common form. It is most probable that this variety is dis- tinctly western, as there are no records of its having been bred in the East. No attempt was made to secure the earlier stages of the insect, and, as far as observations were made, its life history is similar to that of the normal form of the codling moth, as the larvee from which this variety was bred were taken with the larvee of the normal form under bands on apple trees. One might theorize on what conditions -in the West have given rise to this new variety, but to state with any degree @The generic name Cydia used by Mr. Busck before his investigations, which resulted in the restoration of the old name Carpocapsa. 13 of certainty exactly what has brought about this change is impossible from the data at hand. GEOGRAPHICAL DISTRIBUTION. The original home of the codling moth is not definitely known, but is supposed to be southeastern Europe, the home of the apple. It has followed the distribution of the apple closely until it is now present, with but few exceptions, in all countries where apples are grown. It has spread over Europe, and is present as far as the apple region extends in Siberia. It was noted in Australia about 1855, Tasmania about 1861, New Zealand in 1874, South Africa about 1885, and Zeller received it from Brazil in 1891. Mr. C. L. Marlatt reports that he did not observe this insect in either Japan or China in his extended travels in those regions. Mr. George W. Compere also states that he has never observed it in China. Prof. A. B. Cordley states that this insect has reached China. Eyvi- dently some correspondent of his has reported it as present in that country. As apples are being continually shipped to both Japan and China, it is but a question of a few years when it will either be intro- duced or become injurious in the orchards of those countries. Extended researches of many investigators have failed to give date or definite information as to the time and manner of introduction of the codling moth into America. For a long time injury to the apple by this insect was thought to be the work of the plum curculio; and it was not till J819 that the codling moth was reared from wormy apples by Burrell. It was evidently quite well distributed in the eastern United States before its work was identified, as there are but few records of its spread. In 1840 it was a serious pest in New Eng- land and central New York. About 1860 it invaded Iowa. For many years it has been a serious pest in Canada. Mr. Alexander Craw stated in 1893 that the insect was first introduced into California by means of some fruit brought from the East to Sacramento for exhibi- tion purposes in 1872. No measures were taken to destroy the insects in this fruit, and two years later its presence in abundance was noted. Later it was rapidly distributed over the State, aided by the system of returning boxes. Dr. C. V. Riley mentions in 1876 that this insect was then present in Utah, where it had evidently been introduced a year or two previously. From these points of infestation the codling moth spread over the Western States. Prof. J. M. Aldrich states that it has been known in the Clearwater Valley in Idaho since 1887. Mr. I. L. Tiner, of Boise, states that in 1887 he found the first indication of this insect at Boise, Idaho. Mr. Thomas Davis, of Boise, states that it was intro- duced into his orchard at about the same time. 14 RELATION OF DISTRIBUTION TO LIFE ZONES. Although the codling moth may be brought into a section of country, it may not be able to obtain a foothold on account of the adverse cli- mate. In other regions it is never very injurious, or it may be quite injurious one year and almost absent the next; but in warmer regions it reaches the maximum of destructiveness. In order to study these conditions the writer has used the life zones of Dr. C. Hart Merriam (Pl. I). Upon consulting this map one finds that there are seven different zones in the United States. In the eastern portion they, in a general way, extend east and west, while in the western part they are broken into irregular areas by the mountain ranges. There are many important subdivisions of these zones, depending principally upon the amount of moisture and the milder and more temperate climate near the seacoasts. BOREAL ZONE. The principal apple-growing regions of this zone are in Nova Scotia, northern Maine, northern Michigan, and western Owsegon. Except for the Pacific coast strip, only the more hardy varieties of apples are grown in this zone. There is a great lack of definite data in regard to the exact amcunt of injury the insect causes in this zone. As near as the writer can learn, the injury is never so great as it is in the next warmer zone. Deen to Cordley, the insect is present in small numbers in the Pacific coast strip and is doing but a comparatively smail amount of injury. TRANSITION ZONE. The transition zone includes the greatest. apple- producing regions of the United States, the Alleghenian area comprising the zone in the eastern mountain States, including the larger part of the apple-grow- ing regions of New York, Pennsylvania, and Michigan, Although the injury, which varies with the seasons, is greater in the transition than in the boreal zone and less than in the austral, no record of definite percentages has been found during the present study. In the arid area of the transition zone the loss is less than in the Alleghenian area. Various estimates of from 5 to 25 per cent of damage have been given. At Moscow, Idaho, which partakes more of the Pacific coast strip characteristics than of those of the arid area, Professor Aldrich records the amount of injury as 21 per cent for 1899, 10 per. cent for 1900, and 5 per cent for 1901. Professor Piper states that in 1898 the average damage about Pullman, Wash., was 10 per cent, and some orchards were injured 25 per cent; in 1902, about 5 per cent. Professor Gillette reports from 35 to 80 per cent at Fort Collins, Colo., varying with the degree of infestation in the locality. 15 Cooley reports an injury of 95 per cent in small home orchards in Helena, Mont. There are many regions in this faunal area in which the insect does about 25 per cent damage, and for some reason, prob- ably climatic, the injury is reduced to almost nothing for several years, after which the numbers of the insect: gradually increase. Professor Aldrich records that in 1899 an early snowfall and low tem- perature at Moscow, Idaho, killed a great many of the larve: -There are many other localities in the Pacific Northwest where the codling moth either has not been introduced or has not thrived, and in which the injury is nominal. In many regions where the transition zone is pierced by valleys of the upper Sonoran zone the orchards near the canyons suffer much greater injury than those more remote therefrom. Professor Piper has noted several cases in which this was true, and in one the damage was 75 per cent or over. THE PACIFIC COAST TRANSITIONAL AREA, This area includes those portions of Oregon and Washington be- tween the Coast Mountains and the Cascade Range, parts of northern California, and most of the coast region of the State from near Cape Mendocino southward to the Santa Barbara Mountains. In Oregon varying percentages of injury have been reported, ranging froma nom- inal loss to 75 per cent. In the Hood River Valley in some cases it is greater than this, with an average, perhaps, of about 25 to 90 per cent. UPPER AUSTRAL ZONE. The upper austral zone is divided into two areas by reason of the greater humidity of the eastern portion. THE CAROLINIAN FAUNAL AREA. This area includes the great apple regions of the Central States and many smaller portions of the Eastern States. Many entomologists have reported injury in these areas as ranging from 30 or 50 per cent to practically 100 per cent. UPPER SONORAN FAUNAL AREA. This area includes that portion of the upper austral zone west of the one hundredth meridian. From many countings and estimates from various sources we find that in badly infested districts the injury varies from 80 to 95 per cent under normal conditions, and it is very common to find the loss reach 100 per cent. LOWER AUSTRAL ZONE. In this zone there are only a few localities where apples are grown on a commercial scale. Under normal conditions in badly infested 16 localities the loss is almost. total. Garcia records, from check trees in spraying experiments, that the loss varied from 67 to 99 per cent. There are many localities in this zone in both east and west where apples can be grown, but on account of the injuries due to the codling moth other crops are grown instead. IMMUNE REGIONS. In many regions of the Far West one often hears the fruit growers say that on account of the peculiar climatic conditions of that region apples are free from injury and the codling moth can not exist. Among these climatic conditions quoted are dense fogs, mountain breezes, and comparatively high altitudes. Seven or eight years ago it was thought that the Hood River Valley was immune from the insect; the same was thought of the Pajora Valley in California; but later developments have shown that immunity was due to the fact that the insect had not been introduced into those localities. It has also been said that there was no codling moth near the coast in Oregon, but Professor Cordley finds that it is present in some localities and believes that the former immunity was due to isolation. In many restricted areas in the Pacifie Northwest more or less isolated the codling moth is either absent or present in such small numbers that it has not been observed. From past experience and examination of these localities it is evident that the insect in its gen- eral spread has not yet reached them. It is a question whether or not the insect will be injurious in these localities, but it is certain that it can be present. The writer has no hesitancy in concluding that there is no region in the Pacific Northwest in which apples are grown in which the codling moth can not exist. Many causes of immunity by isolation in river valleys have been noted. The most marked case is at Mr. I. B. Perrine’s orchard at Blue Lake, Idaho. The nearest orchard is 18 miles distant down Snake River, while there are no orchards in the other direction inside of 75 to 80 miles. This orchard was free from codling moth until three or four years ago, the larve having undoubtedly been intro- duced in old apple boxes about that time. MEANS OF SPREAD. There are several ways in which the codling moth can be distributed. The most prolific source of distribution comes from the shipping of fruit from an infested region. Fruit which contains the larval insects may be shipped great distances, and when the larve complete their growth they spin cocoons, and in due time the moths emerge, and with unerring instinct seek the nearest apple trees. Many larvee are found to have spun their cocoons in the angles and cracks of the boxes Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE II. Fic. 1.—APPLE LEAF INHABITED BY CODLING MOTH. a, Point where larva entered midrib, at junction with one of the principal veins; b, portion of burrow exposed (photograph by Prof. A. B. Cordley). Fia. 2 —APPLES DAMAGED BY UNKNOWN CATERPILLAR. (Reduced from photograph by the author.) Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE III. EGGS OF THE CODLING MoTH. Natural size of eggs at a and b; e, showing red ring in egg; es which the larva emerged: h, showing the egg enlarged, w the ovipositor of the female. (From Slingerland. ) , egg, showing the hole through ith the larva inside; 0, the end of 17 or barrels. In many localities it has been the practice to return to the fruit grower for refilling boxes in which fruit has been marketed. This practice has supplied the means of rapid distribution in such ocalities. If infested fruit is shipped any distance in cars the larve spin their cocoons in cracks and holes inthe walls of the car and may be carried great distances before the moths emerge. This is thought to have been the source of the infestation at Kalispell, Mont. When apples are stored by commission houses the larve may crawl into boxes or cases of various kinds of merchandise and thus be widely distributed. In sections where the orchards are near each other the spread is accomplished by the moth flying from one to another; but when they are many miles apart, which is especially the case in the Far West, this means of distribution doubtless has little influence. The insect can probably fly a few miles with the aid of the wind, but ordinarily 4 to 6 miles froma source of infestation, over unimproved land, gives partial if not complete immunity. We have no authentic record of the distribution of the codling moth with nursery stock, but one can readily see how this could occur, as the larve might be in the cracks in the ground wround the trees or night crawl into the packing and thus be carried great distances. ESTIMATED LOSSES.” Of all the insects affecting the apple the codling moth causes the greatest loss, and many estimates have been made of the damage. In 1889 Professor Forbes indicated an annual loss in the State of Illinois of $2,375,000. It is estimated that in 1892 the insect caused $2,000,000 loss in Nebraska. Professor Slingerland estimated that in 1897 the insect taxed the apple growers of New York $2,500,000 and the pear growers $500,000. In 1900 one-half of the crop of Idaho was dam- aged, while in 1901 the loss was much greater. Mr. McPherson esti- mated the loss in Idaho in 1902 as $250,000. In many sections of the Pacitic Northwest the annual loss is from 50 to 75 per cent. From the nature of the case it is most difficult to estimate the annual loss in the United States on account of the many factors which enter into the problem. By taking the estimates of the annual crops of apples as given by the American Agriculturist, it is found that for the years 1898, 1899, 1900, 1901, and 1902 the average crop was 47,000,000 barrels. From 1896 to 1902, inclusive, the average price at New York, Boston, and Chicago on October 20 of each year did not exceed $2. Allowing $1 for packing, transportation, and other charges, for aThe estimates under this heading have been revised from the original figures given by the author to correspond with the latest data,—C, L. M. 6514—No. 41—08-—_2 18 47,000,000 barrels at $1 we have a cash valuation of $47,000,000 for the first and second qualities. It is well within the limits of safety to estimate that one-fourth more apples would have been placed on the market had it not been for the codling moth. This one-fourth would be about 12,000,000 barrels, and would have no value except for cider or local sale at very low price. The average price for cider apples is about 30 cents, which price would yield a total of about $3,600,000 as the value of the windfalls, culls, and cider apples, while if they were average apples, at $1 net per barrel the value would be $12,000,000, showing an annual loss of about $8,400,000. The loss in home orchards, in which the percentage of loss is far greater than in the commercial orchards, is estimated at $3,000,000, giving a total annual! loss of $11,400,000. The loss in the country at large or any section of the country will vary with the size of the apple crop. In years of full crops the com- parative injury is not so great as in years when the crop is small and the prices high. FOOD HABITS. This insect is essentially a feeder upon rosaceous fruits, and to them all of the injury is done. FRUITS INFESTED. The apple is by far the most infested fruit. It is the natural food of the codling moth, and under ordinary circumstances is the only fruit injured, save pears. It is quite safe to assume that the larve of the codling moth originally fed upon the leaves of the apple and that the habit of burrowing in the fruit is acquired. Much has been said and written as to the resistance by different varieties of apple to this insect. In Bulletin 35, new series, Division of Entomology, the writer gave a list of varieties and indicated the resistance. It is a notable fact that the summer varieties of apples are very attractive to the second gen- eration of insects. Varieties which are fragrant, as the Pewaukee and Ortley (Bellflower), are always badly infested. As a general rule, one can say that the harder and less ripe late apples are not attacked to the same extent as those which are ripe and fragrant when the second generation enters. It is impossible, from the nature of the case, to determine the exact ratio of resistance of tbe varieties. In one orchard one will find fruit of the Ben Davis variety least infested, while in another it will be the most infested. These differences are without doubt due to local conditions in the different orchards. Pears are next in order of infestation. Under ordinary conditions they are not injured to any great extent. In the Pacific Northwest in badly infested localities the injury rarely reaches a total of 20 per cent. When remedial measures are used this is reduced to from 5 to 15 per 19 cent. Several pear orchards have been noted which were located in neglected orchards in which there were few or no apples. The second generation of the insect seemed to concentrate its destructiveness on the pears, and in one case fully 80 per cent and in another about 50 per cent were injured. One fruit grower in Texas reports an injury of 50 per cent. ‘rab apples are not usually so badly infested, but instances have been observed where they suffered fully as much. Many records also show that peaches, prunes, plums, cherries, quinces, and apricots are infested by the codling moth, but under ordinary conditions their injury amounts to practically nothing. In eases where there is a lack of apples and the infestation is very abundant considerable damage results. There are records of +40 per cent injury to peaches where the trees were quite near an apple house in which infested fruit was stored. NUT-FEEDING HABITS. There are several European records of this insect in walnuts and oak galls. In 1887 Dr. Howard carefully sifted these reports, and concluded that the evidence was not sufficient to definitely prove that the insect ever feeds upon either walnuts or oak galls; and it was highly probable that the larve, if they were larve of the codling moth, went into the latter for the purpose of spinning their cocoons. In 1895 Mr. Adkin exhibited a specimen of C. pomonella which was bred from a species of chestnut, and in 1896 gave details as to rearing this insect from walnuts, and offers the explanation that these nuts bear fleshy coats, or that the insect was originally a nut feeder. Theobald in 1896 wrote that in his investigations, extended over many years, he had never himself bred Carpocapsa pomonella from walnuts, but had found both C. splendana and Plodia interpunctella. Mr. West stated that he had also bred the insect from chestnut. Dr. Riley in 1869 recorded that he had a specimen of a moth which had been bred from the sweetish pulp of a species of screw bean (Strombocarpa monoica) obtained from the Rocky Mountains. Pro- fessor Cockerell raises the question of the correctness of this record. In 1894 Professor Bruner reported that it is highly probable that the insect feeds in the seed buds of roses. In 1901 the writer carefully searched over many hundreds of these seed buds of roses near a badly infested orchard, and did not succeed in finding a single one that was in any way injured by the codling moth. LEAF-FEEDING HABITS. Professor Card in 1897 recorded that the young larvee, especially in confinement, nibbled portions of the leaf. The writer has noticed many times leaves that had been eaten where he thought the work 20 was done by this insect. Professor Cordley has succeeded in making some observations upon this leaf-feeding habit which are of great value. Inarecent letter to the writer he details his experiences as follows: It was found on June 4 that these eggs had hatched and nearly all of the larv:e were dead. Two of them, however, had fed upon the leaves, were yet alive, and had made some growth, notwithstanding the fact that the leaves had been taken from the tree nearly a month before and were therefore presumably not in the most palatable co - dition. Both larvee were feeding upon the lower parenchyma of the leaf, and one had completely covered itself with a web holding pellets of frass. A recently hatched larva, mounted in balsam, measured 1.35 mm. in length; the larger of these two larve at this time measured 1.80 mm. in length and was proportionately stouter. Both were transferred to fresh leaves, upon which they fed until June 8, when one of them disappeared. The other continued to feed until June 11, when it too disap- peared. However, I noticed a slight discoloration of the midrib of the leaf, near where this larva had been feeding, and on carefully opening it found the larva feeding as a miner, it having already excavated a tunnelabout 15mm. long. Ithen examined the other leaf, in which I found the larva that had disappeared three days before likewise feeding in the interior of the midrib. The laryee were again transferred to fresh leaves, and by the following morning each had again disappeared withina midrib. Both laryvze continued to feed within the midribs until June 16, when one of them, on being transferred to a fresh leaf, refused to eat and soon died. The other, with oceasional changes to new pastures, continued to thrive until June 25, when it was plump and active and apparently in the best of health and spirits. Unfortunately Iwas then absent from the laboratories for some days, and when I returned the larva was dead. I believe that with careful attention it could have been brought to maturity on a diet of leaves alone. When one considers that it lived and grew for more than three weeks upon leaves that had been severed from the tree sometimes for several days, and that it was apparently more thrifty between June 16 and 25 than in the earlier days of its existence, one must acknowledge that, while the proof is by no means positive, the indications are that codling moth larve may fully develop on a diet of perfectly fresh apple leaves without ever having tasted fruit. (See Pl. I, fig. 1.) The writer has many times taken larve from apples and placed them upon leaves in cages and bottles. It was found that the larvee would fasten the leaves together with silk and eat holes in them; but on account of lack of attention no larvee were bred to maturity. The writer believes, and agrees with Professor Cordley in believing, that the larve with proper care can be brought to maturity on the leaf diet alone. , This question of the leaf-feeding habit of the codling moth is one of the most important questions in the life history of the insect, and should especially commend itself to entomologists for future investi- gation, since not only will it give us a very important biological fact, but it will also prove very definitely how spraying is effective against the insect. It has often been recorded that larvee gnaw cavities in rough rotten wood, bark, cloth, paper, and other places where they spin cocoons, and the bits of these substances incorporated in the cocoons. From 21 observation it is evident that the larve do not eat any of these sub- stances. When Paris green was placed under the bands and on the bark and in other places where the larvee spin, it was found that none were killed, even when the poison was abundant, which tends to show that they do not eat of these substances. PRIMITIVE FOOD HABITS. Writers have indulged in speculation as to the primitive food habit of this insect. The other species of the genus are nut feeders, and Adkins expresses the opinion that this insect was originally such, and that the habit of eating apples was acquired. The older writers have said that the insect was probably a leaf feeder. From the experience of Professor Cordley this view appears to be the more probable one. WORK OF OTHER INSECTS. There are many other insects which feed on apples whose work may be taken for that of the codling moth by those who are not familiar with the characteristics of the respective insects; but in all instances there are differences in the work and habits of the insects by which they may be easily distinguished. The apple maggot (Trypeta pomonella).—This insect is quite injuri- ous in the northeastern States, and its work in the apple is characterized by many winding tunnels through the fruit. The larva is footless, and has no distinct head, but tapers toward the front. This maggot is the early stage of one of the two- winged flies. The peach twig-borer (Anarsia lineatela).—Injury to peaches and plums by this insect is often at- tributed to the codling moth, as its 44g second generation feeds in the fruit. p,, 1.—Anarsia lineatella: a, twig of peach, The lar Te are much darker red and showing in crotch minute masses of chewed cae x : 5 ‘ bark above larval chambers; b, latter much much smalle1 than those of the cod- enlarged; ¢c,alarvalcell, with contained larva, ling moth, and the mature larv: much enlarged; d, dorsal yiew of young larva, tapers toward either end (fig. 1). more enlarged (from Marlatt). The plum curculio (Conotrachelus nenuphar).—TVhis insect often attacks apples, but can be easily distinguished by the crescent-shaped scar made in egg laying, by the small punctures caused by the adult in feeding, and by the fact that the larva, though it has a distinct head, is footless. The Indian-meal moth (Plodia interpunctella).—This insect feeds upon edibles of nearly all kinds—meal, grain, seeds, nuts, dried fruits, 22 etc. There is a common notion among some farmers that the larva of this insect is that of the codling moth, and the writer has often been told that the codling moth was introduced by its larve being imported in dried fruit. We have no reliable rec- ords of the codling moth having ever eaten dried fruit, and the Indian-meal moth is the princi-- pal insect that has been reared from such sources. The Fic. 2.—Plodia interpunctella: a, moth; b, chrysalis; c, caterpillar; hae lars aI f, same, dorsal view—somewhat enlarged; d, head, and e, first caterpillar Is much abdominal segment of caterpillar—more enlarged (from Chitten- smaller than that of den). the codling moth, and can be easily distinguished from it (fig. 2). The apple fruit-miner (Argyresthia conjugella).—The larva of this insect has been found attacking apples in British Columbia, and injuries which may have been caused by it have been noted in Washington, Idaho, and Montana. The larve are about one-fourth of an inch in length, are of a dirty white color, tinged with reddish when full grown, and taper at each end. The tunnels made in the fruit are numerous, and extend in all directions. There are two species of Lepidoptera which do great damage to apples in Japan, which may sooner or later succeed in en- tering this country. Apple fruit-borer (Laverna herellera).— This insect is said to have gained a foot- hold in British Columbia. The larvee live only at the core of the fruit, injuring the seeds. When full grown they make a pas- sage out, crawl or drop to the ground, and spin a white coccon in the earth. They hibernate as pups, and there is only one) 6=3— ame herellera: o,-ndnhe a ; b, same, side view; ¢, larva; d, co_ generation each year. The species 18 coon; ¢, injured apple—all slightly shown in fio. 3, which also illustrates its ¢mlatged except ¢, which is reduced 5 : (redrawn from Matsumura). e manner of work. Pear fruit-borer (Nephopteryx rubizonella.)—It is stated that in Japan the pear crop is injured to the extent of 30 to 50 per cent each year by this insect: The eggs are laid in clusters on the twigs and 23 leaves, the larva making its way thence to the nearby fruits, which it enters. The principal work is around the core of the pear. The larval stage lasts three weeks or more, and the pupal stage is passed within the fruit. The insect hibernates in the egg stage. The moth, larva, and pupa are illustrated by fig. 4. Unknown caterpillar working on outer surface of apples.— Opportunity is taken of pre- senting the reproduction of a photograph of apples injured by an insect, which in its larval stage somewhat resembles the codling moth, but which we have as yet failed to rear and identify. The injury was first brought to the attention of the Division of Entomology by Mr. D. W. [| Coquillett in October, 1901. The apples furnished were pur- chased in open market in the city of Washington. The in- jury appeared to be almost ex- clubiveryeon vheouter SUT face, ame ivephopterye | rubriconciia. adult above; larva consisting’ in the euttine away just beneath, egg mass on twig at right; damaged =. = 2 5 pear with pupa at left—all natural-size (redrawn of the skin and disfigurement from Matsumura). of the apples and considerably depreciating their value as salable articles (see Pl. I], fig. 2). In some cases holes entering the fruit to the depth of about eae toanie of an inch were found; in one apple to the depth of one-half inch. In November Dr. L. O. Howard also furnished specimens of apples showing injury by the same species. One of the larvee spun up and formed a cocoon November 6. Unfortunately all the larve died with- out our securing the moths. The following brief description of the larva was made: Reddish flesh-colored, head dark brown, central portion of face whitish and trans- parent, with two black spots; cervical shield transparent, except for caudal margin Three setze on the pre-spiracular tubercle. Length, five-eighths of an inch when spinning cocoon. It will be noted that the injury illustrated and described is quite different from that mentioned and figured on pages 87 and 88 of Bul- letin No. 10 (new series) of the Division of Entomology. 24 LIFE HISTORY. Of all insects the codling moth has the largest number of biog- raphers. It has been studied in nearly every country in the world and in all climates in which it exists. The early accounts were always more or less vague and inexact and gave rise to many false ideas. Gradually these points were worked out until to-day we can say that the life history of the insect is as well if not better known than that of any other. Yet, with all the knowledge we have of it, there remain several important points to be determined by future work. It is a fundamental principle of economic entomology that in order to successfully combat an insect the life history of that insect must be given a keen, searching study. With few exceptions these studies reveal some point in the life of the insect at which it is vulnerable to preventive or remedial measures. Without this knowledge efforts are wasted and in some cases are a positive aid to the insects. It can not be too strongly urged that each fruit grower make himself familiar with the life history of the codling moth from personal observation, for by doing so he is placed in a position to understand the reasons for measures of control and to exercise his ingenuity in applying the same to his own orchard. The ease with which collections can be made in the larval stage and the accessibility of literature pertaining to it should specially com- mend this insect to teachers as a subject for nature-study lessons. In the present studies upon this insect particular care has been taken to keep the different stages under observation in exactly the same con- ditions of temperature, moisture, and light as were present in the orchard in which the cages were located, and as a result the writer is able to present some definite data in regard to the effect of temperature upon the length of the stages of the insect under normal conditions. As in other lepidopterous insects, the life of the codling moth is divided into four distinct stages—egg, larva, pupa, and adult. In the winter and early spring the larve may be found in their cocoons in various places, as in cracks and holes in the trees. Later the larva transforms into a pupa, and this in turn changes to a moth, which in turn lays ege's. THE EGG. Since the time of Roesel many authors have mentioned the egg of the codling moth and stated where it was laid, but it was as late as 1893 that it was first accurately described and figured. In 1874 Mr. W. H. Hurlbut described the egg as being about one-eighth of an inch in length and nearly white. Riley described it as being very small and of a yellow color. Messrs. A. J. Cook, Koebele, Weir, and others undoubtedly saw the eggs, but Cook in 1881 and Miss M. Walton doubtless saw the eggs of some other insect. | 25. In 1893 Professor Washburn gaye an accurate description of the egg, with the first figure of it. This figure shows a well-formed embryo inside, but the network of ridges near the center is much too open. Stingerland in 1896 and Card in 1897 distinguished the eggs and made many observations which added materially to our knowledge of this stage. In his 1898 bulletin Slingerland publishes many excellent photographs and descriptions which caused the eggs to be familiar objects. Influenced by Slingerland’s and Card’s work, Aldrich, Cord- ley, Gillette, and others have from time to time added to the sum of our knowledge of this stage of the insect. It is remarkable that, in spite of the many studies of its life history, the egg escaped notice for so long and when seen was not described and figured until a com- paratively late date. The egg is a flat, somewhat oval-shaped object with a flange around it. It varies in size from 0.96 to 1 by 1.17 to 1.32 mm. Commonly speaking, it is about the size of a pin head. The surface is covered with a network of ridges which are much closer together toward the central portion than around the edge. The color depends upon the age of the embryo; as when the egg is first laid it is of a pearly white color, sometimes with a decided yellowish tinge; later it is darker on account of the red ring. The eggs are always glued to the apple or leaf and one often finds shells which remain for some time after the larva has hatched. The reflection of light from the egg is of the greatest aid in finding them, and they have often been described as reflecting the light like “trout scales.” (See Pl. III.) PLACES WHERE LAID. Having never seen the egg, the early writers were forced to guess as to where it was laid. They stated that the eggs were laid either in the stem end or in or about the calyx end of the apple. These views were held because of the position of the entrance holes of the larve. These ideas were published again and again for over a century, and American writers copied them until about 1897, when, by a series of observations, it was proved that they were incorrect. In 1889 Koebele and Weir stated that the eggs are laid at any point upon the apple and are ‘‘as a rule laid elsewhere than within the calyx.” Washburn in 1892 found that the eggs were ‘‘ placed on both sides and the top of the fruit.” In the spring of 1896 Slingerland found that in con- finement the moths laid eggs on the sides of the cages, on leaves, and on bark. Card in 1897 found that the eggs were laid almost exclu- sively upon the upper surface of the leaves, and in 1897 only 2 eggs were observed in the field. In a recent letter Professor Cordley states that out of 15 eggs laid in confinement the greater number were 26 on the fruit, and that he has never seen an egg of the first generation upon the fruit in the field. The apparent contradictions of these observations may be accounted for by the fact that they were made upon the eggs of different gener- ations of the insect. The writer has found that in Idaho but few of the eggs of the first generation are laid upon the fruit.. In one limb cage a moth laid 21 eggs, only one of which was upon the fruit; and in another cage 24 eggs were laid and only 2 were upon the fruit. Very few eggs of this generation were observed to have been laid upon the fruit in the field. Professor Cordley suggests that the moth does not lay eggs upon the young fruit on account of the pubescence, which is afterwards lost. This is most probably the cause. In the field one can often find fruit, surrounded by leaves, upon which there are no eggs, while several may be found upon the upper surface of the leaves. A good percentage of the eggs of the second generation are laid upon the fruit in the field. When the fruit is scarce a larger number is found upon the leaves. The average of several rough countings in the field gave an average of about 50 per cent laid upon the fruit. Breed- ing records show that out of 175 eggs of this generation in limb cages on inclosed branches and fruit there were 71 eggs upon the leaves, 95 upon the fruit, and 9 upon the twigs. Very few eggs are laid upon the underside of the leaves, and it seems that the moth much prefers a smooth surface upon which to oviposit. We may therefore conclude that the eggs of the first generation are for the most part laid upon the leaves, while the majority of those of the second brood may be found upon the fruit. WHEN THE EGGS ARE LAID. Various writers have stated that the eggs were laid at night. Cooley records that he observed a moth depositing eggs at about sun- set. The writer’s observations show that the oviposition for the most part is accomplished in the late afternoon or early evening, while a single observation shows an egg to have been laid sometime between 9 and 12 o’clock in the morning. THE NUMBER OF EGGS LAID BY ONE FEMALE. There is probably less definite data on this point than on any other in the life history of the insect. Many guesses have been ventured as to the number of eggs that one female will lay, varying from 12 to 300 and over. LeBaron found from 40 to 60 eggs, with an average of 50, in various stages of development, in the ovaries of the female at the time of emergence. He adds that if all the undeveloped eggs came to maturity this number must be increased. Matthew Cooke said that he had a vial in his possession in which a codling moth laid 85 27 eges. The writer was unable to secure eggs in this way. In only two instances has the writer made definite observations on the number of eggs laid by a single female moth. Two pairs of moths were secured in copula and placed in separate limb cages. In one cage 21 egos were found, but as the moth escaped the observation was incon- clusive. In the other cage 25 eggs were laid, but a spider put an end to the experiment before a definite conclusion was reached. In view of these incomplete observations the writer can only venture an opinion that the maximum number of eggs laid by one moth is about 50, with the average between 30 and 40, which is comparable to defi- nite records of other insects of this family. THE EGG-LAYING PERIOD. Upon dissection of the ovaries of the female of the codling moth the eggs are found in various stages of development. It is also noted that eggs are laid when they are in different stages of maturity. From these facts we may conclude that the egg-laying period extends over some time. Various authors have given the length of time from the emergence of the moth to the beginning of the laying of the eggs as from 48 hours to 6 or 8 days. Professor Gillette gives the time as about 5 days. The various records of writers show that this time varies from 2 to 7 days, with an average of from 4 to 5 days. \ DURATION OF EGG STAGE. In 1746 Roesel stated that the egg hatched in 8 days. Recent authors give the length of the stage as follows: LeBaron, one week; Wash- burn, 5 to 10 days; Riley, 4 to 10 days; Slingerland, one week; Card, 8 to 10 days; and Professor Gillette, 6 to 8 days in his laboratory, with a known temperature, and in the orchard one day longer. | Cooley records 12 days as the length of the stage of one egg. The results of observations upon 164 eggs and observations of Pro- fessor Cordley are given in Table I, with the total and average effect- ive temperature to which the eggs were subjected. Taste 1.—Duration of egg stage of codling moth. Periodor Total ef- | Average Dates Number} Date | Number incuba- |, 1ective | effective Sac, Papeaay laid. | hatched. | hatched. nian tempera- | tempera- : ture. ture. 1902. 1902. Days. 6 SIN oat ok WEIS: GLO ac Eee Spe ee Se he ee ee Sa a ee 21 | June 11 1 12 228 19 June 12 3 | 13 253 19 {eee June 13 17 | 14 347 24.7 ee mite er esas slatiera's Stara 2etmicteiere' oc Hea aes = aie see cea] ate Sa eiaiec)acel ee or eine Rell Oe aie Sehcigels 2 NDEI D2 Se tae ae te ea 7 | Aug. 21 3 9 | 206 23 Aug. 23 5 12 266 22 PAE LO omer torts sett cls dete S ws nso cielo wees 6 | Aug. 25 6) 9 217 24 LASTS, DS Scenes ae eee ne oe i ae 9 | Sept. 5 6 | 11 247 22 Sept. 6 3 | 12 276 23 28 TasBLe I.—Duration of egg stage of codling moth—Continued. - Total ef- | Average Ny x : Iw Period of} 4.44; rad fpnjze WARGL Nee | Pee uber | apie fective | effective aid. | ‘d.| hatched. Fal tempera- | tempera- | | ‘ ture. ture. 1902. 1902. Days. Cos OR VATED fee oe ae at seer cera 27 | Sept. 5 8 9 278 30 Sept. 6 14 10 307 27 Sept. 8 2 12 360 27 BATT AO reste © 6 aan tals mista cietnte elec ere ae 61 | Sept. 8 3 11 269 24 | Sept. 9 4 12 295 24 | Sept. 12 32 15 364 24 Sept. 15 2 18 428 24 DO Peacscc oot ee cee eee keeenepenase ene | 14 | Sept. 9 1 12 216 18 H Sept. 6 ila 9 269 29 | Sept. 15 1 18 428 24 INE DU) oe So saede soece spoanisnedasosdessss 40 | Sept. 8 | 3 10 254 25 | Sept. 9 5 11 286 25 Sept. 12 3 14 349 24 | Ten ines 14)". Ss CORDLEY. | | ar. NERY [en ee ae ee te oe | Sh aroatey AL HES ee 24 298 12 DON es Seen e en ase os Se oO ee apace dU ayy Fal Eee BM ape ope 5 285 47 The results under normal orchard temperature give the length of the stage from 9 to 18 days, with a weighted average of 11 days. This average is longer than has been given by other authors, which may be accounted for by the fact that it is the usual custom to keep the egos in laboratories rather than under normal orchard conditions, and that the times of the laying of the eggs were estimated. HATCHING OF THE EGG. Recent authors are quite well agreed as to how the larva breaks or eats its way out of the shell. Professor Slingerland was most proba- bly the first to observe this operation. He states that the larva came out of the egg near the edge at one end through an irregular crack in the shell. (Pl. III, es.) The writer has never observed this emer- gence, but upon examining many egg shells an irregular crack was always found which was almost always at one end of the shell. CHANGES DURING INCUBATION. When laid the egg is of a translucent pearly color, often with a yellowish tinge. Observations upon 88 eggs show that from 2 to 5 days with a weighted average of 3 days after being laid a red ring makes its appearance. This ring appears gradually at first whitish, then yellowish, and later quite a brilliant red. By observations upon 56 eggs it was found that in from 7 to 10 days, with a weighted aver- age of 8.4 days after being laid, the egg loses the ring and in its place the larva can be seen, the ‘*‘ black spot,” which consists of the head and cervical shield, being the most conspicuous part. Professor Gillette states that his assistant, Mr. E. P. Taylor, found the red ring to appear in from 2 to 3 days after laying and the black 29 spot appeared 2 to 3 days later. This shorter average may be accounted for by the fact that these eggs were kept at a higher tem- perature than normal. METHODS OF OBTAINING EGGS. There are two ways of obtaining eggs for study. The first is to collect them in the field and place them under observation in cages. There is a serious objection to this method, as there is no way of b | . knowing the age of the eggs. The second method, that of confining larve and pupe and allowing the moths to emerge, is far more satis- factory. If these moths are placed in a cage over a limb of a tree, one will find eggs in abundance ina day or two. One is sometimes fortunate enough to find moths in copula, and in that event they =o) “ should be placed in a separate cage. By determination of sex of the various moths much more valuable data can be secured. Care must be taken that too many eggs are not laid in one cage, as in that event it is difficult to keep accurate notes. These limb cages are bags made of mosquito netting of finer mesh than the ordinary netting. By this method the leaves and fruit are always fresh and the conditions are exactly the same as in the orchard. INFLUENCE OF TEMPERATURE UPON THE LENGTH OF THE EGG STAGE. It has often been stated that a higher temperature caused the eggs to hatch in a shorter time, but only a few definite observations have been recorded. The temperature used in these calculations is the effective temperature, which is obtained by subtracting 43° from the mean daily temperature as recorded by the United States Weather Bureau station at Boise, Idaho. Professor Gillette gives 63 days as the length of this stage at a tem- perature of from 68° to 70° F. and 6 days as the time in a greenhouse where the temperature was 110° F. at midday. In Table I the total and average effective temperature is given from the time the eggs were laid until they were hatched. These data are arranged accord- ing to the temperature in Table I. TasLe Il.—Hffective temperature and period of incubation. Average! Total | Average | Total Average! Total effective | effective Length || effective | effective| Length || effective | effective | Length temper- | temper- | of stage. || temper- | temper- | of stage. || temper- | temper- | of stage. ature. ature. ature. ature. ature. ature. ) Jif SES i Days. Ne | NYG Days. Ser COR: Days. 12 298 | 24 24 217 9 25 | 254 10 18 216.) 12 24 269 11 25 280 11 19 228 12 24 295 12 27 | 307 10 19 253 | 13 24 349 14 21g} 366 12 ay 247 il 24 364 15 29 269 9 22 266 12 24 428 18 30 | 278 9 23 206 9 24 428 18 47 285 5 23 276 | 12 25 247 14 | Average total effective temperature, 302° F. 30 This table is not complete, in that not sufficient observations were made at lower and higher temperatures; and it is dangerous to make any extended conclusions therefrom. A study of the table shows: First. Under a low temperature the length of this stage is longer than at high temperatures. Second. The total temperature varies from 206° to 428° F., and the average is 302°; and in general eggs have to be subjected to this amount of heat before they hatch, whether it be for a longer or ashorter period of time. Third. The eggs are not at the same state of maturity at the time of oviposition, as at 24° we have from 9 to 18 days as the length of stage. Fourth. Under normal field conditions a small difference in temper- ature causes but little change in the length of the stage. MORTALITY AMONG THE EGGS. Various observers, among them Washburn, Goethe, Card, Slinger- land, and Cordley, have found that many eggs of this insect did not hatch. There is little doubt-that at least one of these writers mistook eggs from which the larve had hatched for dead eggs. The writer has noted that many eggs became hard and dry, while in others the contents changed to a dark brown color. These changes may have been caused by infertility, parasites, or the excessively hot sun. The mortality as shown by our breeding-cage records is by no means so great as the writer had supposed. The eggs, however, were more or less protected. THE LARVAL STAGE. Considering the codling moth in its economic relations, it may be said that the larval is the most important stage of the insect. Not only is it distributed, and does all of its damneen in this beet but it is more amenable to moe measures. At the time of hatching the young larva is from one-twentieth to one-sixteenth of an inch in length, of a semi-transparent whitish or yellowish color, with large, shiny, black head, and dark cervical and anal shields. The body shows regularly arranged spots with short hairs or sete. If hatched upon the apple the young larva seeks a place to enter, which is in general some irregularity upon the apple or at the calyx Slingerland, Card, and Cordley have made many excellent observa- tions upon the place of entrance. When hatched upon the leaves they may not find an apple for some time, and subsist by eating small por- tions of the leaves. In confinement this often occurs, but it has never been determined accurately how often it takes place in the field. The writer has time and again noted these spots on the leaves in the field, and has noted also that larve hatched on leaves would have to go from bl 10 to 20 feet before they could find anapple. Card notes that compara- tively few eat of the leaves in the open, but from such observations as we have the writer is strongly of the opinion that it is quite a gen- eral habit. DESCRIPTION OF FULL-GROWN LARVA. When full grown the larvee are about three-quarters of an inch in length, and their heads measure from 1.54 to 1.76 mm. across the broadest portion. The majority are of a pinkish or flesh color, which is much lighter or absent on the under side. It was thought for a long time that the pink color was due to the larva having fed on some particular varieties of apple; but the white and pink larve have often been found feeding on fruit from the same tree. The head is brown in color, with darker markings, while the cervical and anal shields are much lighter. The spots in which the minute short hairs are situated are but little darker than the body wall, but can be easily distinguished with a hand lens. The mandibles are the most noticeable feature of the mouth parts. Beneath the under lip is the spinneret, from which the silken thread is drawn. The larva has eight pairs of legs. The first three pairs, or true legs, are situated on the thorax, and are three jointed. Later these form the legs of the adult insect. The five pairs of fleshy abdominal legs, or prolegs, disappear in the pupal stage of the insect. The first four pairs of legs are armed with circles of hooks, while the hooks on the two pairs at the end of the body are arranged in a semicircle. The spiracles or breathing apertures of the larva are arranged on either side on separate segments of the body. (PLY , fio. 12) ENTERING THE FRUIT. The usual place of entrance of the first generation is by way of the calyx. The larve either squeeze their way into the calyx between the lobes or tunnel into the cavity at the base of the lobes. «A scar, the stem, or a place where fruits touch is often selected as the place of entrance. In 1900 the writer observed an egg shell with a larval entrance hole at the edge and partly under the shell. In view of later observations it is more probable that some larva crawling around found this obstruction and entered, rather than that the larva entered the fruit directly from the shell. The second generation for the most part enter on the sides of the fruit. The larva crawls rapidly about the apple, seeking a place for entrance. A scar or roughness is a favorite place, as the jaws slip on the smooth skin. In its wanderings the larva spins a silken thread and finally makes a web over the surface of the apple. With this asa foothold it is able to make some impression upon the skin, which is bitten out in chips and dropped into the web. Later, when it is partly covered, the larva backs out of the burrow and brings pieces out with 32 it. This is repeated until it is entirely within the burrow, when it turas around and spins a silken net over the hole, in which may be incorporated several pieces of the fruit. (PI. IV, fig. 1.) Slingerland, Card, and Cordley have also noted these larve enter, and the observations made by the writer agree entirely with theirs. One of the essential points noted is that while entering none of the larve seem to eat any of the fruit until well within the burrow, and it most probably gets some of the poison applied in spraying when it attempts to pierce the skin. The writer has observed numerous larger larvee, and is quite positive that they do not eat any of the fruit while they are entering. PLACES OF ENTRANCE. The places of entrance of the successive broods are quite different. Various authors have stated that from 60 to 80 per cent of the larvee of the first generation enter the fruit by the calyx. In 1901 several countings gave an average of 83 per cent, with a minimum of 79 per cent. In 1902 much more extensive countings gave a maximum of 93 per cent, a minimum of 50 per cent, and an average of 81 per cent. (Table II].) Less than one-half of 1 per cent enter by the stem end, while the larger remaining percentage enter the side, especially where fruits touch. The majority of the second generation enter the side of the fruit. A few counts in 1901 showed that the greater part of the larve entered the side, and a few cases showed that from 90 to 100 per cent had entered at that place. Countings on 1,478 apples in September, 1902, on both sprayed and unsprayed trees, are given in Table II. Tasie I11.—Percentage of first generation entering calyx. SPRAYED TREES. Per cent Orchard. | Variety. Date. Stem. | Side. | Calyx. | Total. in calyx. o pPRee) Pee | | IM@RDETSON) Js 22s se- a er eee | Jonathan ..... July 18 0 | 2 | 2 23 91.3 Taree oneness eee ce sen eee | Ben Davis....] July 22 | 0 | 2 28 30 93.3 DAGECKEleN = eae cece sam ee ee |----- GOsmatoaee July 19 0 | 8 8 16 50 | | Posted {9221 beers eee bias als DoS ete a age | Ol: 32 | 38 69 82.6 UNSPRAYED TREES. ils oars é re ED acnayie tee se. ooh sss 50. | eee eee eee oes July 17 2 31 | 67 100 67 MD OEAEE Racer eee see 3 Se shasta ere July 19 0 38 | 62 100 62 DO ete Pera cee eee see se (eee Bee ee eat ae July 21 0 4 | 23 | 27 85.1 DOL eee eee ae oe ead a ieee ote July 25 0 Yi 23 30 76.6 Dr Colusteres eee nee cess | Wealthy...... July 22 0 Piet. 936 257 91.8 MeClelignes- 2s eeeo.s seeeees- ARO Sack mse July 31 0 2 | 13 15 86.6 Mota 3 se one Ane el Pec aa sears 2} 103] 424 | > 529 80.1 | Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE IV. Fig. 1.—ENTRANCE HOLES OF LARVA. OF THE SECOND GENERATION. Fig. 2.—VIEW IN ORCHARD OF HON. EDGAR WILSON, SHOWING LOCATION OF APPLE HOUSE IN RELATION TO ORCHARD. Fic. 3.—ANOTHER VIEW IN ORCHARD OF HON. EDGAR WILSON, SHOWING LOCATION OF APPLE HOUSE WITH REFERENCE TO THE RAILROAD. wy oe *y a h a a ay he et _ Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE V. FIG. 1.—CODLING MOTH LARVA (ENLARGED ABOUT 3 TIMES). Fig. 2.—THE WORMHOLE OR EXIT HOLE OF THE APPLE (ENLARGED). Fic. 3.—A Wormy APPLE, SHOWING THE FAMILIAR MASS OF BROWN PARTICLES THROWN OuT AT THE BLOSSOM END BY THE YOUNG LARVZ (FROM SLINGERLAND). 33 . Places of entrance of the second generation. UNSPRAYED TREES. | | |p ire’ Stem. Side. Calyx. | Total. cua 4 66 57 17a, 44d 5 74. 31 | ALOU eee 12 104 76 192 39.5 4 97 41 EE? Oye 1 20 12 33 36.3 | i 58 14 73 | 19.1 27 | 419 231 677 | 426.1 | SPRAYED TREES. 1 56 28 85 32 11 204 21 236 8.8 0 37 36 73 49.3 0 41 14 55 25.4 0 32 9 11 21.9 0 50 34 84 40. 4 0 19 18 37 48.7 0 50 21 71 29.5 1 11 12 | 24 50 0 32 16 48 33.5 0 22 73 29 24.1 0 | 9 9 18 50 13 | 63 | 225 801 | @28 a Average. The tables of the places of entrance of the first generation on sprayed trees show some interesting facts, and it is to be deplored that the records are not more extensive. No definite data was secured in regard to what percentage of the larve enter the sides where fruits are touching. In badly infested orchards it is almost impossible to find such fruits into which a larva has not entered. It would be safe to estimate that fully 50 per cent, if not more, of the larve entering at the sides enter where the fruits touch. Immediately after entering the calyx cavity the larva takes its first meal. We have a lack of data as to exactly what is eaten, but most probably the larva acts as it does when the side is entered. After spinning the web over the hole the iarva, when it enters the side, eats out a cavity under the skin and throws out but little castings. This mine is eaten outward from the point of entrance, and in from 3 to 5 days the larva begins its tunnel toward the center of the fruit, reach- ing that point when about one-quarter grown and about a week old. — While at the surface, or while tunneling toward the center of the apple, the larva pushes its excrement and frass through the entrance hole. ‘Later the entrance hole, especially at the calyx, is enlarged, and a considerable amount of frass is thrown out, which characterizes the infested fruit (Pl. V, fig. 3). When a considerable cavity has been made in the interior of the apple the excrement is bound together with silk. Upon reaching the central portion of the fruit the larva eats 6514—No. 41— ae B4 out an irregular cavity about the core, and seems especially partial to the seeds. The insects pass through five larval stages, and increase in size by shedding their skins four times to allow for growth. The width of the head of the larva in these different stages averages as follows: First stage, 0.88 mm.; second stage, 0.55 mm.; third stage, 0.78 mm.; fourth stage, 1.12 mm.; fifth stage, 1.6 mm. When in the latter part of the first stage and the second part of the third stage the larve are whitish in color, but with the cervical and anal shields black, and with blackish spots around the sete. In the later stages the shields become brown, and the spots around the hairs are usually indistinct, especially in the pinkish larve. TIME SPENT IN THE FRUIT. Very few definite observations have been made in regard to the time the larva spends inside the fruit. Le Baron gave the time as four weeks; Riley, 25 to 30 days; Slingerland, 20 to 30 days; Card, 10 to 14 days; and Cordley, 16 to 24 days. From the nature of the case it is most difficult to get exact data on this point, as there are many accidents which may prove fatal to the experiment. On only 5 larve was the writer able to obtain results definite enough to use with any degree of confidence. One of these larve remained in the apple 14 days, two 18 days, one 21 days, and another 26 days. Professor Gil- lette kindly furnishes some unpublished data on this point, in which he finds larve to have stayed in the fruits 12, 18, 20, and 24 days, respectively, with an average of 19 days. The average of all these observations is about 20 days. PREPARATIONS FOR LEAVING THE FRUIT. When about full grown the larva makes a passageway to the out- side of the fruit. This is usually made toward the side of the apple, in a different direction from that from the entrance hole. Rarely does the exit passage follow along or consist of the enlarged entrance passage. Before the larva has passed outside the outer portion of the passage is filled with a block of frass (PI. V, fig. 2, 7), or a cap of silk is spun over the hole. LEAVING THE FRUIT. When ready to leave the fruit the larva pushes out this block or tears away the cap of silk, crawls out on the surface of the apple, and immediately seeks a place in which to spina cocoon. (PL. V, fig. 2, 0.) If the apple is upon the tree the larve will, in by far the greater num- ber of cases, crawl from the apple to the twig, from there to the branch, and thence down upon the trunk of the tree. Another method, which is comparatively rare, is that in which the larva lets itself down 35 to the ground by means of a silken thread. This may be on account of the fact that the larve sometimes drop accidentally and use the silken thread to support themselves. It is not uncommon to find these threads extending through the branches of trees which are badly infested with the codling moth. Professor Gillette finds that 85 per cent of the larvee enter the bands during the night, and the remaining 15 per cent during the day, in August. Observations of the writer show that in the summer the larger percentage enter the bands from 6 p. m. to about 11 p. m., at Boise, Idaho. After 11 p. m. it is usually so cool that there is but little activity. In September the conditions as given by Gillette are about reversed. The nights are cold, and the larve are active only during the warmer varts of the day, at which times they enter the bands. If the apple has fallen to tue ground the larva simply crawls into a convenient place and spins its cocoon. After leaving the fruit the larva is unprotected, and does not consume much time in finding a place to start its cocoon. PLACES OF SPINNING COCOONS. In orchards the cocoons are normally found in cracks or holes in branches or trunks of the trees, under scales of rough bark, and in the rough bark on the main branches of the trees. When the trunk of a tree is smooth the cocoons are often found under bits of bark and in the earth about the foot of the trees. Cocoons are found under anything on the tree or leaning against it, as bands placed around the trunk, rags tied around the limbs, or boards and sticks leaning against the tree. When much fruit h s fallen the larvee seem to havea greater range in spinning cocoons, often placing them among clods of earth, beneath paper or any other rubbish on the ground, in the cracks and rough bark of adjacent trees, in piles of wood or lumber, in fence posts, and under the pickets of fences. In piles of fruit in the orchards the cocoons are normally found placed among the apples; in orchards where the trunks and branches of the trees are smooth, the cocoons are often found in the cracks of the earth about the foot of the trees, and when fruit is lying on the ground they have been found among the clods of earth by Cordley and McPherson. Cordley published a photograph showing a cocoon on a clod of earth. In the writer’s experience two cases have been found in which’ a cocoon was spun inside of wormy fruit. It was impossible to tell whether or not the larvee which had spun these cocoons were those which had done the injury to the fruit. In packing houses it is quite common to find the larve in cracks of the floor, walls, and roof, in piles of lumber or boxes, and in the angles and cracks of boxes or barrels used for han- dling the fruit. The larva usually gnaws out a cavity in which to 36 spin its cocoon. These cavities are often found in the interior of rotten trees, stumps, and fence posts, with passages excavated into these rotten pieces of wood from 2 to 4 inches. In the spring cocoons can be found only in the more secure places, those spun in more exposed places having been eaten by their enemies. (See Pl. VILL.) DESCRIPTION OF THE COCOON. The cocoon is composed of silk, which is the product of the pair of silk glands common in many orders of insects. These glands are sit- uated on either side of the alimentary canal, and consist of three parts, each of which has a separate function. The cephalic portions unite to form a single tube in the head of the insect, which extends to the external opening orspinneret. The spinneret is a chitinous projection on the under side of the labium or lower lip. Throughout its life the larva makes use of this silk in various ways. When a suitable place has been selected for the spinning of a cocoon the larva begins to weave about itself this single thread of silk. The exterior outline of the cocoon conforms to that of the cavity or crack in which it is placed. While spinning the larva is bent upon itself and decreases considerably in size. When the cocoon is completed, which takes usually about one day, the larva straightens out and con- tracts in length. While the exterior of the cocoon may be rough, the interior is always smooth and oyal in shape. At completion of the spinning of the cocoon the alimentary canal, silk glands, and other organs peculiar to the larva begin to disintegrate. In from 1 to 19 days, with an average of about 6 days, the larval skin is shed and the insect becomes a pupa. The cast larval skin can always be found at the caudal end of the body, shriveled into a rounded mass. Various authors have noted that when the cocoon of the codling moth is torn or cut open, it is immediately repaired by the larva. Professor Slingerland states that the damage is repaired in winter. He has also had a larva spin two or three complete cocoons after hay- ing been removed very early in the spring from the one in which it had hibernated. The writer had one spin two new cocoons during the summer. Professor Gillette notes that in Colorado the larvee leaving the cocoons in the early spring ieave those in which they have hibernated and seek other places in which to spin new ones and pupate. He reports that under 10 bands placed on the trees in the early spring 6 larvee which were spinning new cocoons were taken. Various reasons might be assigned for this habit of the insect. It might be that the cocoons are too deep in the wood of the trunk of the tree for the moth to emerge without materially injuring itself, or it may be that the larva on becoming active in the spring finds itself in a wet place, and, for either of these or some other reason, migrates to a better place and spins itself a new cocoon. 37 One of Professor Gillette’s correspondents reports that he tound 53 larvee under 295 bands in two weeks. Another reports 307 larve April 2 and 409 April 17 from 2,500 bands. Gillette thinks that the number caught under these bands is too small to be of any great value as a remedial measure. DURATION OF THE STAGES IN THE COCOON. On account of the direct influence of this question upon the system of banding, particular care was taken to ascertain the duration of the cocoon stave, and especially the minimum time. The older writers gave estimates of this time with but little definite data. Riley gave from 15 to 21 days; Washburn, 3 weeks; Slingerland, 2 to 3 weeks, and Aldrich about 1 week. Professor Gillette gives records of com- plete experiments upon this point. In 1900 observations made for him upon 104 larve gave a minimum of 12 days, a maximum of 29 days, with an average of 20 days. Other experiments directed by the same writer in L901 on 76 larvee resulted in finding the minimum to be 3 days; maximum, 23 days, and average 163 days. In 1900 the writer found that in 7 cages the shortest time varied between 12 and 15 days, with an average minimum of about 14 days. In 1902 a large series of breeding experiments were carried out, the results of which are incorporated in the following table: TasiE LY.—Duration of life of the codling moth inside the cocoon. = a Total | Average Number Date |, = : Spee Nes aaa Date of entering band. of | moths ie Bee | Time. | effective effective Tanyeee | emerged.|° moths. tempera- | tempera- ture. ture. 1902. 1902. Days. aA ths ons JIN Es Boe Ree ee rae, a, eee ae 16 | July 19 ») 20 433 21 ay DIL 2 22 505 23 July 22 2 23 | 43 24 AUTEURS 6.2 oases et ae ne Seatac eee 39 | July 30 1 16 494 31 July 31 4 17 §28 31 Aug. 1 5 18 566 31 Aug. 6 ul 23 722 31 LD Ss pe re ee ata eR Aug. 9 2 18 583 32 Aug. 11 a 20 | 645 32 Aug. 29 1 38 | 1,115 29 Sept. 1 6 Ate etl 0 29 Sept. 5 2 45 1, 284 29 Sept. 9 2 49| 1,392 28 yt Oem seroetcer. Soak A Lae oa em oats | as wae ease Aug. 9 3 11 362 33 Aug. 11 3 13 424 33 Aug. 12 3 14 455 32 Aug. 13 6 15 481 32 Aug. 15 5 La 541 32 Aug. 16 2 18 566 31 Aug. 18 5 20 600 30 Aug. 19 2 21 | 615 29 Aug. 20 1 22 | 633 29 Aug. 21 5 23 | 661 29 Aug. 22 5 24 | 693 29 Aug. 25 2 27 783 29 Sept. 9 1 42 | pala 28 ivilly Goi Ls Sa Sk Ne Bee Se Seer ee eee ars 11 | Aug. 18 2 18 | 535 30 Aug. 19 1 19 | 550 29 Aug. 20 1 20 553 28 2 Aug. 21 1 21 581 28 Aug. 23 3 23 641 28 PATIO AOR me eo aieiais catneie setaia Semon 2 Sans [ees ae ee ae | Aug. 18 il 12 | 209 17 Aug. 19 1 13 | 224 17 Aug. 21 3 15 270 18 Aug. 22 4 16 302 19 i; Aug. 23 3 17 330 19 58 Taste TV.—Duration of life of the codling moth inside the cocoon—Continued. |Number| Date Wimber | Total | Average Date of entering band. | of moths | ofimoths,| -ime- | tempera-|tempera- | larvee. | emerged. a | ture. ture. 1902. | 1902. Days. 2) 2) ATIC MG come esas dmase cece sane sees ereciesasaleccee sere Aug. 25 10 19 392 21 Aug. 26 7 20 425 25 Aug, 27 12 21 456 22 Aug. 28 alee 22 485 22 Aug. 29 5 23 503 22 Aug. 30 3 24 519 22 Sept. 1 7 26 558 21 ATO PIB Seah 2h eet act latom date eid ote ae 8 .-do 1 19 468 25 Sept. 8 3 26 674 26 CSL Dan cue ainse ects p aiee See eee te 26! Fons <0 to) 9 24 604 25 TOT cae ily Bi ae Raeree es A? i 8 | 28 | Sept. 12 5 23 607 26 PANT es te oe kL tat ee ee ee | Ys eet C0) Se 2 21 547 26 | Sept. 17 1 26 633 24 | - The number of larvee used was 170, and the stage varied from 11 to 49 days, with a weighted average of 22 days. This average is some- what longer than that secured by other observers, and may be partly accounted for by the lateness of the season. The principal point to be clearly shown is the length of the mini- mum stage, which these experiments show to be not less than 10 to 12 days. The time spent in the cocoon by the hibernating larve varies con- siderably, but usually lasts about eight months. If the larve are taken inside and kept where the temperature is higher, moths will sometimes emerge in January or February. INFLUENCE OF TEMPERATURE UPON THE DURATION OF THE STAGE. Various authors have stated at various times that this stage might be considerably lengthened or shortened by temperature. Table V shows a preceding table arranged according to the effective tempera- tures and the lengths of time. Tasie V.—LHifective temperature and length of cocoon stage of codling moth. Average| Total | Average | Total Average | Total tempera-|tempera-| Days. ||tempera-|tempera-| Days. tempera- tempera-| Days. ture. ture. ture. ture. ture. ture. ans ers CK. FH: oR: eee 17 209 | 25 604 24 29 1, 284 45 224 13 26 547 21 30 535 18 18 270 15 607 23 600 20 19 302 16 | 674 26 31 494 16 330 17 28 553 20 528 17 21 392 19 | 581 21 566 18 425 20 641 23 566 18 433 20 astral 42 722 23 558 26 1,392 49 32 481 15 2m 456 21 29 550 19 541 17 485 22 615 21 583 18 503 23 633 22 645 20 519 24 661 23 455 14 23 505 22 693 24 33 362 11 24 543 23 783 27 424 13 633 26 1,115 38 25 468 19 1,170 41 39 From the table we find that the minimum total temperature is 209°, - the maximum 1,392°, and the average 592°. The evidence given by this table is insufficient to warrant any definite conclusions. It is quite evident that there are other factors which have not been taken into account, of which moisture and unequal development of the larve when the cocoon is spun are probably the most important. EFFECT OF THE INSECT UPON THE FRUIT. The effect of the injury by the codling moth upon the fruit varies with the variety of the fruit and the season of the year in which the injury isdone. The attack of the larve of the first generation usually causes the fruit to fall. A few of the fruits of fall and winter varie- ties, after having been injured, stay on the trees for the remainder of the season, but the early varieties fall quite rapidly and readily. In all cases the effect of the injury is to cause the fruit to ripen prema- turely. The amount of the windfall of the late varieties depends in great measure upon the amount and violence of the wind. The effect of the injury upon the value of the fruit is variable. If the inside of the fruit is eaten out, it is valueless except for use as cider apples. When the injury consists of only a small defect on the exterior of the fruit, it may be graded as second, and is of considera- ble value. Fruits often bear very small spots where the larvee have pierced the skin but have failed to bore into the flesh of the apple. These spots do not materially injure the apple, and many of them are packed as first-class fruit. In cold storage apples which have been injured by the codling moth are the very first to begin to rot, and are consequently sources of contamination to the surrounding fruit. THE PUPA. The pupal stage of the codling moth is that stage in which the organs that are peculiar characteristics of the larva are broken down and worked over into the tissue of the adult. The pupa is about half an inch in length, and varies in color from yellow to brown, depend- ing upon age, and when the moth is about to emerge it has a distinct bronze color. The head, eyes, mouth parts, antenne, legs, and wings of the moth are apparent in sheaths which are immovably attached to the body. The abdominal segments, which are movable, are each armed with two rows of spines, except the terminal segments, which bear only one each. These spines point backward, and play an impor- tant part in the economy of the insect. The last abdominal segment has a number of long spines with hooks at the end. ‘These hooks are fastened in the silk and aid the pupa in holding its place in the cocoon. EMERGENCE OF THE MOTH. After the pupa has thrust itself out of the cocoon, the pupal skin splits down the back, and the moth forces its way out by splitting - 4() away the head end of the pupal skin. The legs, antenne, and wings are drawn out of their sheaths. The insect is wet, and the body wall is soft. The wings increase several times in size, and as the body dries it grows more rigid. A few moths were observed to have emerged in the field. During the process of expanding and growing they clung to the bark of the trees with their heads up (PI. VI, fig. 1), avoiding the sunlight. When the wings were fully expanded the moths would often hold them over their backs for a few minutes, in a manner simi- lar to the way a butterfly holds its wings. After running about over the tree for a short time the moths fly into the lower branches of the trees, and are lost to observation. | Their quick and erratic flight is similar to that of other moths of this family. The whole process of emergence takes from fifteen to thirty minutes. THE ADULT INSECT. The adult insect or moth is quite variable in size. The wings expand from 14 to 19 mm. Commonly speaking, they never expand over three-fourths of an inch. The whole insect is covered with scales in varying colors. The tip of the front wings bears a large dark- brown spot or ocellus on which there are two irregular broken rows of scales, which have a coppery metallic color, and with some reflec- tions of light they appear golden. Near the ocellus there is a very dark-brown band across the wing, which is more or less triangular in outline. The remainder of the wing is crossed by irregular dark and white bands, an appearance caused by the white tips on the dark scales. In many specimens there is a distinct darker band across the wing, while in others this band is not apparent. The hind wings are a grayish-brown color, darker toward the margin, with a long black line at the base of the fringe. The underside of the hind wings has dark, irregular, transverse markings. ‘The underside of the front wings is of a light-brown color, with opalescent reflection and with a few markings except on the costa. The legs and head and patagia are covered with long, narrow, white-tipped scales, while the body is covered with white-colored scales with opalescent reflections. The large white scales on the caudal margin of the abdominal segments are especially conspicuous. (PI. VII.) HOW TO DISTINGUISH THE SEXES. There are many characteristics by which the males and females may be easily distinguished. As stated by Zeller, the males have penciled, long, black hairs on the upper side of the hind wings. These hairs are sometimes of a light color, which renders them difficult to distinguish. Slingerland discovered that the males could also be distinguished by the presence of a distinct elongate, blackish spot on the underside of the fore wings, which spot consists of a number of black scales. These 41 scales are sometimes of a slate color, which under certain lights ren- ders the spot inconspicuous. There is a great difference between the genital organs of the two sexes, as the ovipositor of the female can be said to be hoof-shaped, and ends, roughly speaking, in a point; while the presence of the claspers on the male can be said to cause the abdomen to end in a line. HABITS OF THE MOTH. - It is generally stated by writers that the adults of the codling moth are but rarely seen in orchards. In cases where the infestation is not very bad this is usually the case; but where the infestation is bad it is a very common thing to see the moths in the orchard, but never in any large numbers. They spend most of their time resting onthe upper surface of the leaves or on the trunks of the trees, where they are hidden by their resemblance to the grayish bark. When disturbed, they fly away so quickly that the eye is unable to follow them in their erratic flight. According to many observers the codling moth feeds on the juice of ripe apples. The writer has often observed them drink- ing water in cages. As the conclusion of many investigations by many persons and under various conditions, it has been definitely determined that the insect is not attracted to lights. A very few records of captures of codling moths at lights, usually of the accidental catching of one or two specimens, have been published. DURATION OF THE LIFE OF THE MOTH. LeBaron gives 1 week as the average length of the life of the adult codling moth, Washburn gives from 10 to 15 days, and Slingerland says that one moth lived in his cages for 17 days. Records of the writer in August, 1902, of forty-seven moths, show that two moths lived 1 day; ten, 2 days; eleven, 3 days; ten, 4 days; two, 5 days; seven, 6 days; one, 7 days; two, 8 days, and two, 9 days; giving a weighted average of 4 days. The length of the adult stage depends upon the conditions under which the moths are kept, as they will live longer if there is water which they can drink. The average of 4 days was obtained when there was no water accessible to the moths; but had there beén water or ripe fruit, the average would probably have been longer. GENERATIONS OF THE INSECT. The question of the number of generations of the codling moth in one season has for many years been in doubt. In recent years ento- mologists have been stimulated to greater efforts and have in a measure solved the problem. The economic importance of this question is very apparent, as the second generation of the insect inflicts about ten 42 times as much damage as the first generation, and it is necessary to know whether a second generation is present in order that the proper measures of control may be employed. Great biological interest also attaches to this problem, as it affords an excellent opportunity for the study of the effects of different climates on one insect. The term ‘‘ generation” is used instead of ‘‘ brood” because it describes more definitely the idea intended. A generation in this con- nection means a number of individuals which pass through certain stages at about the same time, having begun in the same stage at the beginning of any given season. A succeeding generation is the aggre- gate of all the different broods of the individuals of the generation immediately preceding. A new generation is considered to begin with the egg stage, and continues through all the transformations of the insect until the moth dies. Many authors object to the term ‘‘ partial generation,” but as there is a condition in which this term can be used with a definite meaning, it may be well to use it. For instance, in some sections of the country all the insects pass through one genera- tion; a few, becoming more advanced than others, may succeed in passing through the pupal and moth stages and lay eggs, from which larve hatch and enter the fruit, whereas the majority of the insects hibernate as larye and do not transform until the following spring. As those insects which enter the fruit in the fall do not for the most part complete their development, at least in the field, they are termed a partial generation. In tabulating the results of observations in regard to the time of the various stages we find that at certain periods more individuals of a generation are in certain stages than at other times; and likewise we find periods when there are fewer insects of a certain stage than at other times. These periods are designated respectively the maxima and minima of the different generations. It is always considered that the larvee, pupz, and moths found in the early spring belong to the last generation of the preceding season and may be termed the hiber- nating generation. From the writings of European authors we find that there is but one generation of the codling moth in northern Europe, including England (Westwood) and northern and central Germany, while the evidence of Reaumur and Schmitberger shows that at Vienna and in France there are two generations. American writers have at various times recorded many observations of variations in the number of generations in the United States. Fitch seems to indicate the pres- ence of but one generation, while Harris says a few may transform and enter the fruit in the fall, though the majority of the first generation hibernate. Fletcher reports that careful observations extending over ten years convince him that near Ottawa, Canada, there is but one regular generation of the insect, while in the fruit-growing districts 43 of western Ontario there are two generations, the second being inva- riably the more destructive. The observations of Atkins, Harvey, and Munson agree with those of Harris. Slingerland says in 1898 that his observations indicate that in New York a large number of the larve of the first generation develop into moths, the percentage transforming depending upon the weather conditions of the season. In 1894 Smith found by a series of observations that the larve col- lected in midsummer did not transform further that year, but hiber- nated. Later, in 1897, he states that near New Brunswick, N. J., there is positively only a single annual generation, and, further, that soath of Burlington County there is at least a partial second generation. In addition to the observations already given of conditions quite simi- lar to these in New Jersey, we find that Trimble in 1865 carried out a very careful and accurate series of experiments upon the life history of the codling moth at Newark. He found that on August 10 there were three pupx among the insects under observation, and that on August 20 many moths had emerged; on August 23 he found that one in five of the Jarve had transformed. Sanderson finds that there is one generation and a partial second generation in Delaware. He states that of the larve found July 31 about 29 transformed and 5 remained as larve. Taking these numerous observations and the data given in regard to them into consideration, we must conclude that Doctor Smith’s observations are too few in number and do not justity the assertion that there is but one generation of the codling moth at New Brunswick. Many observers in widely different sections of the United States have found two generations clearly defined. Le Baron states that ‘‘in the latitude of Chicago a great majority of the moths of this brood (first) emerge the last two weeks in July.” Riley, after many years of close observation, states that the insect is ** invariably two brooded in Missouri.” Popenoe and Marlatt found two genera- tions in Kansas. Gillette indicates two generations in Iowa. Walton by breeding experiments discovered two generations in the same State. From a series of observations extending over several years, checked by breeding experiments, Cordley concludes that there are two generations at Corvallis, Oreg. Koebele says there are two gen- erations in the Santa Cruz Mountains of California, and the insect probably does not differ in its habits throughout the State. Based upon one of the most extensive studies of this question that has ever been made, Gillette arrived at the conclusion that there are two generations in Colorado. Cooley says that in 1902 there were two generations at Missoula, Mont. Forbes indicates a third generation in Illinois, based upon the fact that very young larvee were found on October 4. Coquillett states that his notes indicate that the insect has three generations in California. Washburn says there are three to four generations at Corvallis, Oreg. Card gives two to four in +4 Nebraska. Cockerell concludes there are three full generations near Mesilla Park, N. Mex. Aldrich in 1900 stated that there were three generations in Idaho, and in 1903 concluded after a series of breeding experiments that there was a partial third generation at Lewiston. At yarious times writers have made assertions that in the warmer sections of the United States a partial fourth brood was produced. In carefully sifting all these statements the writer finds many points which throw doubt upon and render them of but little value, principally because definite dates and localities are not given. The date and exact localities are often of as much importance to future workers, and per- haps of more importance, than the observation itself. METHODS BY WHICH THE NUMBER OF GENERATIONS MAY BE DETERMINED. From the nature of the case the determination of the number of generations of the codling moth is a most difficult problem to solve accurately. The methods used must be scrutinized carefully, and all possible sources of error must be taken into consideration or elimi- nated. The correctness of a conclusion can be assured only by exact- ness in methods and by corroborative evidence secured by different methods. Observations made in orchard examinations have constituted one of the methods largely followed. Although observations are of great value when used in connection with other methods, they often lead to erroneous conclusions when used alone, as it is possible to obtain evidence of the condition of an orchard only from the study of avery small portion of it during a very short period. Past conditions are often unknown, and conclusions obtained are largely based upon pre- conceived ideas. If a large number of insects can be bred throughout the season, much yaluable data can be secured and the problem solved beyond any doubt. As yet we have no records of breeding experiments: carried on throughout the season with the necessary accurate data. The writer has attempted many times to breed the insects throughout the season, but has always failed, usually on account of some unfore- seen difficulty which caused the experiment to end. However, it is believed that with proper care and experience this breeding can be successfully done. Breeding the insect and harmonizing the results of the breeding by observations in the orchards has been the method most used in working upon this question. By breeding the insect through parts of its generations valuable data have been secured, which, if pieced together and corroborated by other methods, are almost as valuable as if the insect had been bred throughout the season. Many entomologists have neglected to increase the value of their breeding experiments by keeping the insects under conditions of tem- perature and moisture different from those prevailing in the orchard and keeping no record or a very fragmentary record of the tempera- 45 tures to which the insects were subjected. Many other records are questionable by reason of the fact that the generation, or the nearness to the maximum of the generation, of the insects placed in the cage was uncertain or unknown. Early in his studies of the life history of this insect the writer saw the necessity of finding some method by which the numbers of indi- viduals of a generation could be approximated at certain times. By an incidental study of the records of larvee captured under bands, published by Professor Aldrich in 1900, it was noted that at a certain time in the season there were fewer larve so caught than at. periods of time immediately following and preceding. By collecting as many records as were obtainable at that time, it was observed that these conditions were quite constant. The efske of the larger and smaller number were termed, respectively, the maximum and minimum of larve entering bands. In 1901 many fruit growers in Idaho, at the request of the writer, kept and submitted records of the larvee killed under bands. Other records, many of which had been made without any idea of the future use to which they might be put, were collected from many sources. These records were tabulated and curves were drawn upon cross-sec- tion paper, using the time as one factor and the number of larve as the other. These curves give quite an accurate picture of the course of the insect in the orchards throughout the season. Not all of the records, however, were satisfactory, as a few of them from various causes gave data which were of no value. The curve showing the effective tem- perature at the dates at which the larve were killed under the bands was drawn upon the same charts and gives quite accurately the effect of the temperature upon this habit of the insect. A number of these records are reproduced (figs. 5 to 16). INACCURACIES OF THE RECORDS. “ There are many sources of possible inaccuracy in these records. The greatest inaccuracy is probably found in the weekly or biweekly band records, because these are composite records of many individual trees and show only approximately the dates of the maxima and min- ima. Many of the records were commenced too late in the season to be of any real value; and when they were started even a little late the curve ascends with rapidity, which would not have happened had the record been started earlier. In consequence of a series of warm days, the maximum number of larvee may enter the bands sooner than they would if the temperature had remained ncrmal; and if the temperature be low for many days, the maximum might be later than it would be normally. Spraying “aes seriously interfere with the accuracy of the record, as at certain periods all of the larve entering the fruits might be killed and thus cause a fall in the curve of larve entering (Note the relation of curve to dotted line, which indicates effective temperature.) Fic. 5.—Daily band record made by H. G. Gibson, Nampa, Idaho, in 1901, upon 4 trees. bands. When counted the larvee were killed, which reduced the number of larve of the succeeding generation. If the tree from which the record is taken should be covered with rough bark or have a large number of holes and cracks in it, the number of larve entering the bands will not be so great as if the band were the only place in which they could hide to spin their cocoons; therefore, filling the holes and scraping away the rough bark would cause a rise in the curve. In most cases the con- ditions which would ren- der the records inaccurate were eliminated when it was possible to do so. In order to show the relations between the daily and the weekly band records, a weekly summary (fig. 6) was made of Gibson’s daily band record. By this means it was shown that the weekly records are only approximate, and show the general trend of the insect in the orchard rather than any details. One writer has suggested that the rise and fall of the temperature would cause a corresponding rise and fall in the number of larvee, so as to obscure the true position of the maxi- mum. By a study of the record made by Mr. Gib- son (fig. 5), in which the 47 effective temperature is shown by a dotted line, many interesting facts in regard to the temperature can be observed. It must be noted, however, that the number of larvee caught on any given day is influ- enced by the temperature of the preceding day, as most of the larve enter the bands at night, some time before midnight, and that they are usually killed and counted some time the following morning, while the observations upon the temperature were taken at 6 a. m. “ E JULY AUGUST SEPT. BOM 2545678 IMLS OT BIMALBABHTBAMIN 2 0.7.8 910 WIZ 1415 1617 1919 202) 223% 252627 BHAIN3|1 234 5b 7B 9 111251415 1617 18920 LBABAY WAM! 2349678 V0i20 Th ena TTT] HHH TT [] I] anne TT] erence i a an a H Fie. 6.—Weekly summary of Mr. Gibson’s band record. and 6 p.m. ‘The great rise which occurred on June 24 was probably due in a great measure to the fact that the bands were placed upon the trees on the 21st. The fall in the number of larve on June 24, the rise on June 27, the fall on June 30, the rise on July 1 and 2, and the fall on July 4 can be partially accounted for by the corresponding rise and fall of the temperature. From about July 5 to August 4 the Jury Aua. SEPT. ‘ . 50] 100 eS 2530) 2°58 -.0F is_ 18 22 25 29] 2 5 8 10 12 14 16 18 202224 27 1 4en Wois 19 24 27 31 3 7:10 #14 18 22 30) 60) 20) 40 Fie. 7,—Band record made by William A. George, Caldwell, Idaho, in 1901. temperature was high, but there was no corresponding rise in the number of larva, as there were no larve ready to enter the bands, the majority of the insects being in the moth, egg, and younger larval stages. This interval of few larve marks the time between the maxima of the generations entering the bands. In the second maxi- mum it can be noted that the rise and fall of the number of larve is 48 usually parallel with that of the temperature, but toward the-end of the record the temperature has but little influence. The record made by Mr. George (fig. 7) and Mr. Ayers (figs. 8 and 9) show practically JULY AUGUS SEP OcT. 123.45 6 7.8 910112151415 16171819 2021 272524252627 2829903) 23 6b 7 8.9 VOM 1219 W415 IbI7IBI9 202172 7524252027BZ303I}1 2 3 4 5 6 7 B 9 1012 13\4I5 1617 18192021722524752627782954 23 45 67.8 9 NONIZIS IS IOTB 26 500 24 aaa 23 22 ra] | 2000 19 18 1 17 | 16 tt 1500 { hI \4 tu 13 Hit || 12 1 i 1000 9 om om on an | 8 7 +++ 6 Fic. 8.—Weekly band record made by Mr. Ayers at Boise, Idaho, in 1897, on 140 trees. the same conditions, but not so clearly, on account of the length of time between the observations. LENGTH OF THE LIFE CYCLE. In order to establish a correct basis for the determination of the number of generations, it is essential that we ere as closely as Fic. 9.—Band record made by Mr. Ayers in 1898. possible the average number of days in which the insect can pass through one generation. Assuming a certain date, with as much accuracy as possible, when the maxima occur in a band record, and taking into consideration all the imperfections of the records, we should have ABET OnE: in the number of days between these max- PLATE VI. Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. Fic. 1.—LARVA, PUP4, AND MOTHS ON ROUGH BARK. —INFESTED APPLES BEING BURIED. 2. FIG Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE VII. FIG. 1.—CODLING MOTH (ENLARGED 4 TIMES). Wing on the right shows the reflections from the gold-colored scales in the ocellus. Fia. 2.—CODLING MOTHS (ENLARGED TWICE). Fig. 3.—CODLING MOTHS (NATURAL SIZE, FROM SLINGERLAND). 49 ima the length of the life cycle of the insect. In the records given we find that the periods vary from 40 to about 66 days, with an aver- age of 55 days, or about 8 weeks. Professor Gillette finds that according to his life history studies upon the summer brood the AUGUST SEP 123.45 6 789 1OII2I51G15 1617181920212223242526272829303I|1 2.345 6 789 101 11215 1415161718192021227524252627 2829303! 23 45 6 78 9101 112131415161718 19 202122252 2526272829 600) 900 400 2300 2200 2100 000 1900 1800 1700 1600 1500 1400 1300 200 1100 1000 900 800 700 600 500 400 300 200 100 0 Fic. 10.—Band record made by David Brothers in Colorado in 1899. period of the different stages is as follows: From egg to larva, 7 days; from larva to cocoon stage, 19 days; from cocoon stage to emer- gence of moth, 18 days; from emergence of moth to middle of egg- Sie Pir 23.45 67.89 101112151415 1617 1819 202122282425 2677 laying stage, 5 days (estimated); total, 49 days, or 7 weeks. From the writer’s numerous records of the lengths of the different stages, however, it is found that most are somewhat longer than those given 6514—No. 41—03 + 50 by Professor Gillette and that the egg stage averages about 11 days; from the hatching of larye to leaving the fruit, 20 days; from enter- ing the bands to emergence of moth, 22 days; from emergence of moth to middle of egg laying (estimated), 5 days; making a total of 58 days, or about 8 weeks. By adding together the shortest times and the longest times, respectively, we find the minimum length of the life cycle to be 36 days and the maximum 100 days. This period of 55 to 58 days having been obtained by these two widely different methods, they are probably not far from the correct average length of the life cycle of the codling moth. SEASONAL HISTORY. By following the development of the codling moth through the sea- son as carefully as possible, we are enabled to throw more light upon the question of the number of generations. Those larves which have escaped their enemies during the winter, if left in the field, change to ULY Aua. Sept. Ocr. pe NE 30} ae 20 30 5 e 19 29 8 18 18 28 200 Fic. 12.—Band record made by Prof, E. A. Popenoe, Manhattan, Kans., in 1890. pupe, according to Slingerland, just prior to the time when the apple . trees are in bloom. He found the first pup April 27, and by the 7th of May about one-fourth had pupated. In 1902 the writer found the largest number of pup about the time the apples were in bloom. Some were found in rotten wood as late as June 10. The location of the larva has the greatest influence upon the period of pupation, those in warmer places pupating more quickly than those in colder situations. EMERGENCE OF THE MOTH. From the records of various writers, as compiled by Gillette, we find that the first moths appeared from April 24 in New Mexico to about May 16 at Corvallis, reg. Mr. McPherson records that in 1901 he found a moth in the field in Idaho as early as April 23, and that the moths were most numerous about May 1. Mr. Hitt in breeding 50 moths found that the first emerged May 5 and the last May 28. In 1902 the writer found that the majority of the moths emerged between May 15 and 20. Cordley states that in Oregon in 1899 moths emerged in some cases April 10, and continued to do so until omy ol. At Ithaca, N.Y. Slingerland found in 1896 that moths emerged from May 38 to June 22, and in 1897 from May 24 to June 7. Gillette records that he found moths out of doors at Fort Collins as early as April 26. The extreme range in time of appearance of these moths was 69 days in their cages. At Fort Collins, ac- cording to Mr. Hitt’s records, this period extends over about 23 days. Professor Slinger- land found that this range was 49 days in 1896. RELATION BETWEEN EMER- GENCE OF THE MOTH AND THE BLOOMING PERIOD. Slingerland states that the moths begin to emerge in New York about the time the apples are in bloom, but the majority do not emerge until after the blossoms fall, and but few lar- ve are found to enter the fruit until about two weeks there- after. Gillette found the first moth emerging about 10 days before the trees were in bloom. He states that the majority of them emerged about the time of bloom, but eges were found July 9, 1900, and June 19, 1901, and were all hatched hy July 21, the trees having been in blossom about May 5 to 15. This would make about a month between the blooming period and the time when the "EQRT Ul “TBO ‘osor UR UL SaeI1 Cg WO TIdRYD Aq ope pode purq—'eT ‘OI 52° first larve hatch and enter the fruit. Card found the eges about three weeks after the blossoms had fallen. Cordley found that in 1898 the first larva entered the fruit about July 1, the egg from which it hatched having probably been deposited about June 21. This enter- ing of the fruit took place about two months after the petals had fallen. The writer found that in southern Idaho in 1902 the apples were in full bloom about May 13, and the first larves were noted to Fig. 15.—One of the records made by H. E. Burke at Boise, Idaho, in 1902, to determine the maximum : of the second generation. have entered the fruit June 11, or about 25 days after the blossoms had fallen. From these few observations we find that the moths may emerge some time before the apples are in bloom, and, depending largely 53 upon locality, the larve begin to enter the fruit from a week to two months after the blossoms have fallen. From the standpoint of the orchardist this is a most important question in considering the effect of the first spraying upon the insect. — JULY Z AUGUST Sie Pain 1 932% 6 7891011 121514151617 1819209 29345 2697989303i11 93 45 6 9.84 101112131415 16171819 2021 2923495 2627 BAY 3II | 2S § 6.7.8.9 101 1121314151617 18192001 232 2B 23d TTT HT HW SS K_] S55 a eS NJ fo . SEER ERE EE Fig, 16.—Record by H. C. Close, Utah Agricultural College. The next point at which we can make any definite observations upon the codling moth is when the larvee are leaving the fruit and entering the bands for the purpose of spinning their cocoons. The band rec- ords give this most valuable data in a very accurate manner. The following table shows the maximum of the different generations enter- ing the bands, according to these records: Tasie VI.—Maximum of larve killed under bands. g a iS a5 # o./% ik % | First | Second | = 5 eI 4 | Time of re-|= 4 Year. Locality. eee Aes aa ~ | maxi- | maxi- | od | 3 Bt movalot ae a 4 : S| mum. mum, | 2a | & 5 bands. /%3 |; EI 2A |S Bue 5 ears pos A A is 4 1897 | Boise, Idaho. .---- AMIR RAU VETS crotce ai = 140} July 17 | Sept. 15 61/12, 247| Weekly ....|. 87.48 1398 [4 2< 2 (6 KOs = ees seeks | eee OSes ees ae 140; July 10 | Sept. 10 62/20; 909)... - Gossens 149. 35 1899 | Juliaetta, Idaho.) Prof.J.M.Aldrich| 40) July 20 | Sept. 24 66] 8,620}..... idOlseae- 215. 50 1901 | Nampa, Idaho-.-.-..| H. G. Gibson -...-. 4) June 26 | Aug. 16 BL 2467)" Dailys 2222" 116. 75 1901 | Payette, Idaho ...| J. Shearer ....-... 3} July 18 | Aug. 17 60] 215) Weekly....| 71.66 1901 Omar. -c226Ss|ecccs OO ease eee 80) July 1] Aug. 30 d 1901 Saleen Olt’ ah -Seeeaeee 12S duly= ove e-Gdows. 1901 Utah Agricultural| 23)....do-...| Sept. 2 College. OOS ae eh O Ornate eaten | ce Moe OOS eres see sone 26) July 13 |} Aug. 27 HOOT | ss GOi eee a 2 Sec e as- (Oh) eae see 34) July 5/| Sept. 2 1901 | Hagerman, Jdaho| R. E. Connor..... 27| July 12 | Sept. 4 : : 1901 | Lewiston, Idaho..| S. G. Iasman ..... 4). .d05.-| Sept. 10 60; 666) 6permonth)166. 6 1901 | Caldwell, Idaho.-| Wm. C. George -.-| 10) June 25 | Aug. 13 49| 640) 2 to 5 days.| 64 1899 | Colorado ......... David Brothers...|....| July 16 | Sept. 15 (il eeeres Weekly ....|------ 1890 | Kansas -...------- E. A. Poponoe....|.... July 25 | Sept. 28 ie eaelenees Gove sas|= anes 1883 | San Jose, Cal ...--. Chapin: .2.=s6--s: 850| July 19 | Sept. 23 66) =H dees ere = GON se53)\--552 54 Riley states that the larvee of the first generation are most abundant about July 8; Gillette, that this occurs in Grand Junction about July 15, at Denver July 21, and at Fort Collins July 25 MOTHS OF THE FIRST GENERATION. Cara found the first moths of this generation about July 2. Cord- ley gives August 1 as the date for the first and September 15 for the last. Gillette gives the following data: Grand Junction, Colo., first July 28, last September 12; Canyon City, first July 15, last Septem- ber 10; Fort Collins, first July 13, last September 12. According to Gillette, the eggs of the tirst generation were most abundant August 12. In 1901 the writer found eggs most abundant between July 15 and August 4. In 1902 they were most abundant about the same time, but were obtained in cages as late as August 29. The dates of the maxima of this generation of the larve going ner bands is well shown in Table VI for the second generation. An examination of these band records as published shows that the period of the larvee leaving the fruit and entering the bands extends over two months. HIBERNATION. The following table by Gillette shows the time at which pupation ceased and the larve began to hibernate at various places in Colorado. It was found, as shown by the table, that pupation ceased between August 10 and August 30, varying with the locality in which the experiments were made. Taste VII.—Proportion of hibernating larve taken at different dates. 2 wy | Number Locality. Dates larve were taken. pee hibernat-| | Record by— aken. ing Grand Junction, Colo.......- DULY AG-2os it G00E. eee eee 33 1 | Silmon Smith. 1 Dye enn ee Sate eee re ee SUly2A-S0 S900 5 ose se eceee eee 53 as Do. Oak Soe eee eee July 3l—Aug 6; 1900-225. -oceen- 60 8 | Do. WO Se a eee eae eres ANIC 'G=lS 900 noe ss eece ace nen tl Saee ce oe cela enseesece Do. ai Us 70 96S 10 0 ae aan en A, Se 79 78 Do. Pegi a7 a 2] 0 es 130 130 Do. &. 30=Sept..4, 1900)... oo ees 192 192 Do. 5 1-6, OOD mre eronrs arses Semeste 22 5 | H.H. Griffin. . 7-11, 1900. ae 14 4 Do. g. 12 2 -14, 1900... 51 14 Do. E 66 56 | Do. 22 28) 115 115 Do. g, 39 Sept. 6, 1900 80 80 | Do. y 30, 1899. 25 0 | Dr. R.J. Peare. g. 1-13, 1899. 70 30 Do. g. 14-20, 1899. s 50 44 | Do. 25-28) 1809). ce seer ek oe 100 99 Do. Cordley has for several years been unable to breed any moths after September 15. In 1900 the writer found that pupation had ceased September 1, and in 1901 September 7. In 1902 more extensive breed- ing experiments were carried out, from which it was found that pupa- tion began to grow less about August 1 and entirely ceased August 22, and that no moths emerged after September 17. 55 At various times records have been made of finding single moths late in the season, in October. The presence of these moths can be easily accounted for by the fact that the larvee probably got into some place where the general outside temperature had no effect on them, and increased temperature caused transformation. EVIDENCES OF A THIRD GENERATION. It is often found that in September a large number of the fruits have been entered by very young insects, and it is also found that in some localities these injuries extend into October. This has given rise to the belief that there is a third generation present; and not having definite records in regard to the life history of the codling moth, many fruit growers have come to the conclusion that there are three gener- ations, and some have even gone so far as to say that there is a par- tial fourth generation. Many entomologists have taken these state- ments from the fruit growers, and not having given as complete study to the subject as was possible, have published the conclusion that three generations were present. The writer has collected all of the publi- cations in which three generations were either indicated or given as occurring, and has, with the greatest of care, studied the observations upon which the conclusions were based. Many entomologists have submitted original notes or copies of the notes from which their con- clusions were drawn. After carefully studying all these records and published accounts the conclusion was reached that there were only two publications in which any substantial evidence is given as to the existence of a third generation of the codling moth. Professor Cock- erell, in a bulletin of the New Mexico Experiment Station, concludes that there are three generations and a partial fourth. Professor Cock- erell relied mainly upon observations, and checked these observations by breeding experiments in only a few instances. The observations, while of value, give the conditions in the orchard at irregular inter- vals, and then only for a very short period of time. Many erroneous conclusions were drawn from these observations. For instance, the finding of an empty pupa case on June 26 was considered an evi- dence that the moths of the first generation had emerged. In view of the fact that Professor Gillette finds that the extreme period of emer- gence of the moths in the spring is 69 days at Fort Collins, and that Professor Slingerland found moth in New York as late as June 22, we see that there is the greatest probability that these moths were the latter part of the hibernating generation, instead of the first part of the first generation. The finding of wormy apples on July 3 was con- sidered as the beginning of the second generation entering the fruit. On August 12 small larve in fruit were considered to be the beginning of the third generation. Anyone familiar with the conditions of Western orchards knows that small larve entering the fruit can be 56 found almost any time in the summer. From the evidence given by | Professor Cockerell the writer is of the opinion that there are only two generations of the insect present in Mesilla Park, and that there is no sufficient evidence of a third. Professor Aldrich in a recent bulletin states that, in his opinion, there is at least a partial third brood at Lewiston, Idaho. This con- clusion is arrived at as a result of some very carefully conducted experiments which give evidence, by breeding records, which up to a certain point is indisputable. By caging the insects at proper inter- vals Professor Aldrich obtained moths of the second generation on September 3 and 4. There is no doubt in the mind of the writer that these were moths of the second generation. But Professor Aldrich failed to state whether or not he obtained eggs from these moths, and instead of doing so took unknown field conditions to carry out the remainder of his experiments, taking it for granted that the larve entering after September 6 hatched from eggs which had been laid by moths of a similar age to those emerging September 3 and 4. As the latter were of the very earliest of the second gen2zation, there is no reason for assuming that the larvee which entered after this time were not larve of the retarded portion of the second generation. By using the length of the life cycle with the data given it is obvious that these larvee belong to the second generation instead of a third. CONCLUSION. By taking into consideration the evidence which has been derived from the band records, from breeding experiments, and observation, the writer has no hesitancy in concluding that there are but two gen- erations of the codling moth in the arid sections of the West, and that it remains to be proven that even a partial third generation of the insect is present in any part of the United States. The writer admits, however, the possibility of a partial third generation in the West and South, and that careful, accurate work in the future will give us bet- ter evidence upon this point and settle the question beyond a doubt. By a careful study of the temperatures for several years in the locali- ties where observations have been made upon the number of genera- tions of the insect, the writer hoped to be able to give the total temperature at which the different conditions in regard to the genera- tions might occur; but after a great amount of labor this was found to be impracticable, principally on account of insufficient accurate observations upon the insect, and it was decided to make use of the more general life zones in determining the distribution of genera- tions. It may be stated that the boundaries between these life zones are only approximate; that there are different gradations between them, and that as yet there are many inaccuracies in the map. Mr. Marlatt, from personal experience and the observations of other ento- a mologists, arrived at the conclusion that there was one generation of the insect in the transition zone, two in the upper austral, and three in the lower austral. By using the conclusions of recent years the writex finds that there is one generation in the transition zone, with often a partial second, two generations in the upper austral, and two in the lower austral, with a possibility of a partial third. NATURAL CONDITIONS WHICH TEND TO DECREASE NUMBERS. It has often been noted that a sudden fall of temperature is fatal to a large number of the smaller larve of the codling moth. It has been already noted that Professor Aldrich has recorded such an obser- vation. Hot sunshine and extreme dryness cause many of the pup in the case to die. A moist climate aids fungi and bacteria to such an extent that sometimes most of the larve are killed by them. Larvee that are killed by fungous diseases are hard and mummified, and have a whitish appearance. Bacteria cause the internal organs to dis- integrate and the larva to become limp and full of juices of a brown color. NATURAL ENEMIES. Although the codling moth has many natural enemies, the number as compared with those of other Lepidopterous larvee is comparatively small. This may be accounted for by the fact that the insect through- out the greater part of its life is more or less protected, but when the larvee have left the fruits and are seeking places in which to spin their cocoons and when in the winged stage they are attacked by numer- ous enemies. Birds are by far the most efficient natural enemies of this insect. Anyone who tries to collect the larve from the trunks of trees in spring will find very few specimens, but, on the other hand, will find many empty cocoons. The writer has many times in the spring searched persistently for larve in the rough bark and the more exposed cracks, but found practically none, although many could be secured by cutting into the holes and cracks of the tree. Riley, Walsh, and Slingerland also note this effectiveness, and the amount of good the birds do can only be estimated. The cocoons are always found, and on a close inspection of the bark a telltale hole discloses the story of some woodpecker’s work. It has often been noted also that the same birds have made holes or enlarged the cracks in the stubs of old branches for the purpose of digging out the larve. Plate VIII, figs. 1, 2, 83, shows stubs of branches from an old orchard near Elkton, Md., in which these birds have done efficient work in reducing the number of larve during the spring. Fig. 2 is especially interesting, as on,close examination it shows the following points: Some time in 1900, in the course of pruning the orchard a branch was cut away, leaving the stub, which is 8 inches long. In the following winter and ~ 58 spring the stub began to crack and decay and the bark to loosen. Many codling-moth larvee crawled under the bark in the fall of 1901. The woodpeckers found this stub in the following winter and spring, and not only probably secured all the larvee which were under the bark, but enlarged one of the main cracks in order to get those which were hidden inside. In the fall of 1902 all the bark had fallen from this stub and many more larve took refuge in the cracks. Upon examination, in May, 1903, the writer found that the crack had been recently enlarged, as is well shown in the reproduction. This recent enlarging was probably done mostly by the pileated woodpecker (Ceophelus pileatus), as the chips broken out were quite large, and probably required more strength than other smaller woodpeckers could muster. This stub was sawed from the tree and sent to the writer, and in the latter part of May the moths emerged, and 28 empty pupal skins were found on June 25. The writer estimates that fully 100 larve hibernated in this stub. It is highly probable that all woodpeckers feed on the codling moth larve. Other birds, including the nuthatches, black-capped titmice, wrens, bluebirds, crows, blackbirds, kingbirds, swallows, sparrows, chickadees, and jays, may also feed upon the codling moth, especially those birds which winter in the locality where the larve are present. Without doubt the bobwhite quail, which has been introduced into many sections of the West, also feeds upon this insect. At best our knowledge of the food habits of many of these birds in regard to the codling moth is based upon but little direct evidence; but reasoning from what we do know positively, there is little doubt that codling moths form a part of the diet of at least some of these birds. Not many years ago a movement was set on foot in the Pacific northwest to import the German kohlmeisen into this country, as it was said to feed largely upon the larve of the codling moth; but because the bene- fits derived from the bird in its native home were not clearly proven, and that it sometimes injured fruit, and also on account of many dis- astrous experiences in the importation of birds and mammals which have already been made, the majority of the authorities were con- vinced that it would be a dangerous experiment, and no further action was taken. The expenditure of time and money necessary to carry out such a project would probably be more beneficial if applied to the protection of our native birds. Koebele writes that in California he knows of many small bats fly- ing around the apple trees in the evening, taking moths on the wing, and even darting down to take moths which were upon the leaves. The writer has often noticed bats flying about the apple trees, but was unable to obtain any evidence that they were catching codling moths. 59 INVERTEBRATE ENEMIES. The writer has often found moths in limb cages dead with spider’s silk wound around them, but made no further observations. The insect enemies of the codling moth are either predaceous or parasitic, and are quite numerous as to species, but are usually few as to individ- uals. A large number of predaceous insects in the larval stage have been observed feeding upon the codling moth, the following list being compiled from publications of various authors: Chauliognathus pennsylvanicus. Pterostichus californicus. Chauliognathus marginatus. Calathius rufipes. Telephorus bilineatus. Dermestid. Trogosita corticalis. Clerid. Trogosita laticollis. Chrysopa. Trogoderma tarsalis. Raphidid. Perimegatoma variegata. In regard to many of these predaceous insects it is doubtful whether they feed upon the living codling moth larva or upon dead specimens. At best, they do not reduce the number of the larve to any consider- able extent. In Utah a species of Ammophila was found stocking its burrows with larve of the codling moth. It is also recorded in Cali- fornia that Sphecius nevadensis was found pulling the larvee out of their burrows. Many observers have found the eggs parasitized by a species of Trichogramma. Even in its protected life the larva is preyed upon by many parasitic insects, among which are the following: Goniozus sp. Pimpla annulipes. Macrocentrus delicatus. Bethylus sp. The writer found traces of three species of parasitic Hymenoptera which were preying upon the codling moth in the Pacific northwest, but was unable to breed any of them. Among the Diptera only one para- site is mentioned, namely, //ypostena variabilis. In general it may be said that these parasitic insects are found in such numbers to be of value only in neglected orchards, and in any orchard that is well taken care of, sprayed, banded, and otherwise treated in preventive and remedial ways, these predaceous and para- sitic insects are found in very small numbers or are entirely absent. Even with the host of enemies arrayed against it, the codling moth under normal conditions in the West will ruin practically all of the apple crop, and if success is to be obtained proper measures of con- trol by human agencies must be instituted, and the parasitic and pre- daceous enemies left out of the question, except woodpeckers, which may be encouraged with profit. 60 HOW TO COMBAT THE INSECT. The codling moth seems to have been present and injurious in orchards for centuries, but until about eighty years ago no one seems to have made any suggestions as to how its ravages might be checked. It would require volumes to contain all that has been written about the methods which have been used against this insect—most of them value- less. Before considering methods of combating the insect there are several points which must be discussed. Many of the Western States have horticultural laws which aim at extermination, and many of the corps of inspectors are working with that end in view; others, however, from recent experience have been led to change their views upon the subject. When one discusses the extermination of an insect he ventures upon debatable ground. As yet no insect has been exterminated through the agency of man, and judg- ing from past experiences the writer believes that it is impossible to exterminate the codling moth even in a single orchard. The control of it, by means by which the damage it inflicts is reduced to a minimum, is the very best that we can expect to accomplish. It is a prime neces- sity, in order to make recommendations of value, that the entomologist have an accurate knowledge of the life history of an insect. Not only is this necessary for the entomologist, but it is essential for the fruit grower also to understand it, in order that he may apply recommen- dations intelligently and vary them to suit conditions. The erroneous ideas some fruit growers have upon the life history of the codling moth are sometimes startling, following recommendations simply because they are given to them, and having no idea of the reason therefor, Often they obtain good results, but more often failures result; and as they do not understand the reasons for the recommendations, they are at a loss to know why they did not obtain good results. To combat the insect successfully the fruit grower must be familiar with all the stages of the insect, the sequence of the stages, where found, and hab- its and variations. He should also be informed how the preventive and remedial measures act in reducing the numbers of the insects. With this knowledge he will be able to vary the recommended preventive or remedial measures to exactly fit his local conditions, and if any failures occur he will in a measure be able to tell why they occur, and the fol- lowing year the experience will aid him in changing his methods in order to obtain better results. He will also be protected against using methods which are of no value, and will thus avoid a large unnecessary expense. PREVENTIVE MEASURES. Preventive measures are those which not only aid in controlling the codling moth, but aid the fruit grower in training trees so as to bear more fruit, support it while growing, and produce fruit of a better 61 quality, size, and color. Although many of these questions are not closely allied to the control of the codling moth, they are of impor- tance, as anything which increases the margin of profit aids in secur- ing better general results from an orchard. There are many methods of* prevention which may be applied to keeping the insect out of a section of the country in which it is not yet present. By study of the means of its spread it will be learned how it may have entered the country, and by closing all possible ave- nues of introduction immunity may be secured for many years; but if fruit is being continually shipped into a new country from = an infested district, it is only a question of a few years when in spite of all that can be done the insect will gain a foothold. Whether it becomes injurious or the loss is nominal will depend upon many condi- tions. Many orchardists who have planted young orchards in infested districts are quite desirous of keeping the codling moth out of their orchards as long as possible, but if there are infested orchards near by this is a practical impossibility. It may be said that money and labor spent in keeping the insect out of a section or an orchard will accom- plish more good if directed toward the study of better orchard methods and adapting the measures of control to that section of the country. To insure the best results in the planting of a young orchard in an infested locality the codling moth should be considered from the very first, and everything that is done should be done only after taking into account the actual or probable presence of the insect. If note is taken of these methods and they are faithfully carried out, a great amount of labor and loss will be saved when the orchard is in bearing. There are many questions which can be decided for each locality only after all the conditions over which the fruit grower has no control, such as transportation, exposure, temperature limits, and proximity to water, have been fully considered. Although the question of soils is very important, by appropriate methods the character of some soils can be materially changed, as by cultivation, cover crops, and other means. The first question which confronts a man wishing to plant an orchard is the question of varieties, which is one of the most difficult problems to be solved. The soil, the climate, the purpose for which apples are grown, and various other factors, must be considered, each one having its own bearing upon the problem. If a home orchard, the likes and dislikes of the grower are the first consideration, but if the aim is to plant and maintain a commercial orchard, the question of varieties must be determined, first, by finding what varieties are well adapted to the locality in question. This can be learned by consulting the experiment station officials in the different States and from the experience of growers who have orchards in that locality. The next consideration is what varieties will meet the market demands and com- 62 mand the highest prices. It is a well-known fact that in the arid regions of the Pacific Northwest the Jonathan, Grimes Golden, Rome Beauty, Ben Davis, Winesap, and a few others are the best adapted to a commercial orchard; while in the humid sections of the same region the Newtown Pippin, Spitzenberg, and a few others have proven most successful. It might be well to note here, as has been stated before, that the Pewaukee and Ortley apples are always found worst infested with the codling moth, while the Lawyer and Winesap are least infested. After it has been decided which varieties to plant, the next question is that of buying the stock. Good stock should always be insisted upon, and one can be sure of securing the desired varieties only by buying from well-established, conscientious nurserymen. It is preferable in the arid region of the Northwest to plant 1-year-old stock. The land usually has some vegetation upon it, such as sage brush or timber, and after clearing it the soil should be thoroughly pulverized. If irrigation is intended, the ground should be leveled and graded to facilitate irrigation. The courses of the irrigation ditches should be determined by the general contour of the land, tak- ing into consideration the future routes of the spraying machine, which will draw upon these ditches for water for spraying. SETTING THE TREES. There are many methods which may be used for setting the trees, the details depending on the size of the orchard and the means at hand. The essential feature of the operation is to make the holes large enough to receive the roots of the tree, so that they can still retain their natural position. After filling and packing earth into the holes, water should be allowed to run in, to aid in giving the trees a good start. It has been found that it is a very injurious practice to place any manure in the holes when the tree is planted. If manure is to be applied in the new orchard, the best method is to scatter it over the surface of the ground. Care should be taken to cause the trees to lean toward the south- west, from which the hottest rays of the sun come. By doing so, sun scald will in a great measure be avoided. After sun scald the bark breaks, and the wood is exposed and becomes cracked and decayed. It has often been found that trees thus affected always bear a larger percentage of wormy apples than trees on which the bark is unbroken. This is accounted for by the fact that the codling moth larve go into the cracks to spin their cocoons and are there secure from their enemies. It is a common sight in all sections of the country to see trees planted from 16 to 18 feet apart, with the upper branches intermin- 63 gling so as to form a dense mass of branches which can not be sprayed properly, and there is no room between the rows for wagons or culti- vators. It is strongly urged that the trees be set not closer than 30 feet apart; some growers prefer 40 feet. PRUNING. No arbitrary rules can be made for pruning on account of the fact that every kind of tree and plant, in fact every individual, presents its own peculiar problem; but there is an ideal which the pruner should endeavor to attain. It is found in many sections of the West that the trees have been allowed to fork so that there are two or three main branches, and upon bearing a heavy crop these branches have split apart, sometimes totally ruining the tree. At best, if the branches are brought back into place and held by bolts, wires, or ropes, a crack will be left, into which fungous diseases can enter and in which codling moth lary will spin their cocoons. Such a break should be dressed with grafting wax or shellac varnish, and the branches fastened closely together. With proper pruning, when the head of the tree is being formed, this trouble may be avoided. Instead of two or three main branches, the head of the tree should be so formed as to have four to six, thus distributing the weight, and preventing breakage under ordinary conditions. Many apple growers have headed their trees too high for best results. The disadvantages of this method are that it is difficult to reach the fruit and foliage with spray, and much more difficult and expensive to harvest the fruit. Other growers have headed their trees so low that the branches spread and droop so that they are close to the ground. In many instances when there is a heavy crop of fruit these branches bend down and either touch or lie upon the ground. The result is that much of the fruit on the interior of these trees and on the under sides of the outer branches is so shaded by the foliage that the sunlight can not reach it, and a large percentage will be poorly colored and of second quality. (See Pl. [X.) A mean between this high and low heading is to be desired, which will do away with most of the disadvantages of these extreme methods. In order to secure proper coloring in fruits on trees it is necessary that enough smaller branches be removed to admit an abundance of sunlight through the tops. In the arid sections of the Far West the trees grow with great rapid- ity, and if allowed to take their natural course become slender and not strong enough to support a normal weightof fruit. It has been found that by cutting back half of each year’s growth the trees will be made to grow heavier and stockier, and thus be able to support the weight of a large load of fruit without any danger of breaking. 64 IRRIGATION. Proper irrigation of the orchard depends entirely upon the condi- tions. There are several methods of employing water in irrigation— by flooding, by a system of checks, or by furrows. The latter is probably the most efficient, but care should be taken that both sides of the tree receive an equal supply of water. SOIL OR COVER CROPS. The soil of different localities varies, and the treatment should vary with the conditions. In irrigated sections the soil is usually lacking in humus, and is often packed so closely together that it is impervious to water. By proper tillage this is corrected to some extent, but the greatest success has been attained by growing cover crops. Red clover is successfully used for this purpose, and is advantageous in many ways. The roots penetrate deeply into the soil, thus forming passages for water; by keeping a cover of clover over the soil, evaporation from the soil is retarded, and the irrigation need not be so frequent, as the water is retained for a longer time; the clover can be cut and used for hay; and about every third year the practice of plowing the clover is followed, so that, in addition to the fixing of nitrogen by the roots of the clover, the decaying vegetation adds needed humus to the soil. ORCHARD IN BEARING. A very serious error is made by many fruit growers in regard to the first crop of fruit. Reasoning that the first crop is not worth _trying to save from the codling moth, the grower allows the insect to infest most of it, intending the following year to apply preventive and remedial measures and put it under control. The result usually is that the following year he has an abundance of insects, and his loss will be considerable. If, when the larve were all in this first crop, the apples had been destroyed by being picked and buried, or if bands had been used late in the summer, a large percentage of the loss in the second year could have been prevented. It is often the case that on account of some unforeseen condition, such as a freeze ora frost, the fruit crop is reduced to almost nothing. Under such conditions each grower must decide for himself what methods he will pursue. Usually in such years the price of fruit is very high, tempting the grower to produce all the fruit he can, even if infested. The writer recommends that when the crop is so small that each tree will produce only about one box or less of good fruit, the fruit should be picked and destroyed, not earlier than the middle of July nor later than the middle of August, and other methods such as banding should be used to destroy as many of the remaining insects as possible. Various instances have been under the observation of the writer in which these suggestions were followed with great success. Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE VIII. Bose Fig. 2. STUBS OF BRANCH CUT FROM A TREE, SHOWING WoRK OF WOODPECKER. . FIG. 3.—STUB ABOUT 8 INCHES LONG, SHOWING WoRK OF CODLING MOTH LARVA AND WOODPECKER. Twenty-eight moths which the woodpeckers did not get emerged from this piece of wood. STUBS OF BRANCHES FROM AN OLD ORCHARD NEAR ELKTON, MD. Sera Sa ht watch OCdt aaah Stas Hiatt Sho A te at Ee AO We ORO lene Yat pete OY Us Ojo pS OHV] ‘3SIOG YVAN ‘GOOM LNOW3H4 ‘NOH 4O GYVHOHO Ni MIA eR era ee a ee ee Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE IX. ove oe ; 65 There are many preventive measures which may be applied to the orchard when it is in bearing. It is a well-known fact that an orchard which produces a moderate crop each year is much more profitable than one which produces an abnormally large crop one season and a very small one the next. By thinning each year this alternation may be prevented to some extent. The writer is very strongly of the opinion that if thinning 1s done when the larve of the first generation are in the fruit, and the fruit and larve destroyed, the advantages thereby gained are sufficient to compensate for the expense of thinning. It is easy to see how the destruction of part of the first generation will prevent much of the injury due to the second generation, which is about ten, times that by the first generation. It is difficult for the orchardist to determine by observing the entrance holes about what time the insects are inside the fruit. In thinning, all terminal clusters should be reduced to one fruit, and none should be allowed to grow closer together than from 4 to 6 inches. During the process of thin- ning, with but little increased expenditure of time or money, the wormy fruits can be removed and the perfect left on the tree. Throughout the season a large number of fruits will drop from the tree to the ground. Upon examination it will be found that under normal conditions the larger percentage of these are the result of the work of the codling moth. The percentage varies, however, with many conditions. If a tree is heavily loaded, a large number of good fruits will be pushed off by those nuane, and the wind will cause many to fall. The quantity of windfalls increases throughout the season. The percentage of the larvee to be found inside the wormy fruit varies with the time of the year. In the Pacific Northwest the latter part of June and the first part of July and the latter part of August are the times when the largest number of larve are* found inside the wormy windfalls. In a small orchard these windfalls can be destroyed by allowing hogs to run at large in the orchard and eat the fallen apples; or the windfalls may be picked up every few days and either made into cider or destroyed. In a large commercial orchard, however, it is not probable that the expense of keeping the ground clear of windfalls would be justified by the benefits derived, although such benefits would undoubtedly be great. PREPARING FRUIT FOR THE MARKET. The method of packing which is now coming into use is to pack the fruit in the orchard, using packing tables built upon runners. These are hauled down a row, stopping at intervals. Two rows are picked on either side of the mnie and the fruit is carried from the trees to the tables by the pickers. The fruit is there graded and packed, and 6514—No. 41—03—_5 66 ‘ the culls are left in piles in the orchard. The advantages of this method of packing are many. The fruit is handled but once, and is not hauled any distance until it has been securely packed, and the danger of breaking the skin or bruising is reduced to a minimum. The picking and packing crews also work as smaller units, and can be more easily directed and do far better work. The codling moth larvee in the culls, after completing their development, will, if allowed to do so, spin their cocoons among the apples in the piles. (See Pl. XVI.) Fruit may be well grown, weli colored, and of proper varieties, but if not well packed these conditions are nullified. Apple growers in the Far West are confronted with rather special problems. By reason of their distance from the large markets of the United States, the price they would receive for second-quality fruit would hardly be suflicient to pay the expense of growing, packing, and shipping, and it is incumbent upon them to ship nothing except that which is strictly first class, packed in strictly first-class manner. The cost of transpor- tation, prevailing market price, and size of crop, however, must be taken into consideration. The methods of packing depend upon the kind of package used. Eastern grown apples are usually packed in barrels. From Colorado and Montana westward boxes containing either 40 or 50 pounds are almost universally used. Some are even going further, using small packages containing half bushels of superior fruit. There are many methods of packing the fruit in these boxes, as may be required by the purchasing dealers. In all cases it is highly essential that the fruit be packed so tightly in the box that there can be no shifting of posi- tion while in transit; that there be a decided swell in the boxes on both top and bottom if they are made of thin and flexible wood, as is usually the case in the West; that the paper lining of the box remain unbroken, and that when the fruit is opened it will be attractive to the buyer. The more progressive fruit grower is well aware of the fact that a reputation for first-class fruit can be obtained and secured only by packing such fruit and rigorously excluding all wormy or scale- infested apples. Although it is extremely difficult for a packer to put up a box of apples containing not a single wormy fruit, it should be firmly impressed upon his mind that is the ideal to be attained. The second-quality apples, which are usually disposed of in the local markets, are those but slightly injured by the codling moth, or undersized or uncolored. The culls and windfalls should be piled together and disposed of as quickly as possible. ‘They may be either fed to stock immediately or made into cider for vinegar. The value of these culls is considerable, and progressive orchardists count a good deal on the revenue derived from them. From the seconds, culls, and windfalls in one orchard with which the writer is familiar 67 5,000 gallons of cider were made, which sold ‘for as high as 20 cents per gallon. One bushel of apples made from 24 to 3$ gallons of cider, by means of a hydraulic press run by the gasoline engine used in spraying. If it is not possible to dispose of the culls otherwise, they should be buried in holes in the orchard and covered over with 6 to 8 inches of closely packed earth. (PI. VI, fig. 2.) Occasions may arise when it is necessary to store these for some time, although the storing of such fruit should be avoided if possible. Fruit should be stored in a house in which there are no holes or cracks in the roof or walls. When the larve inside the fruit have completed their development they spin cocoons and transform into pupe, which in turn transform into moths. These. moths emerge, and if there are cracks or holes in the house they will escape and fly to the orchard the following spring. If, however, the house is tight it may be fumigated; or, better still, screens may be placed over the windows, and as the moths collect upon these screens, they may be crushed, or they will die if left a week or so. The writer studied two cases in Idaho in which apples were stored quite near an orchard. (Pl. IV, figs. 2 and 3.) The effect was that the following year the part of the orchard nearest the apple house was always most infested, and in spite of all the remedial measures applied there was a great amount of damage. In California it was found by Mr. De Long that in a house in which apples were stored the moths always emerged and went to the windows. Records were kept of these insects, and it was found that 11,974 moths were killed from April 15 to August 12. One can easily imagine what destruc- tion these moths would have caused had they been allowed to fly to the orchard. PREVENTIVE MEASURES IN OLD ORCHARDS. In all sections of the country old neglected orchards are easily found in which practically all of the fruit is*infested by the codling moth. The writer is quite familiar with two typical orchards, one of which is situated in an irrigated section of the far West and the other in a humid section of the East. Although the climatic and other conditions are quite different the two orchards have many features in common. The western orchard consists of about 300 trees about 18 or 20 years old, planted about 16 feet apart each way. The branches of each tree touch those of the surrounding trees so as to form a dense mass of branches and foliage. Theformer owner of the orchard, find- ing that the codling moth destroyed the larger part of the fruit, gave the orchard no irrigation, and in consequence the trees are in a more or less stunted condition. The branches are thickly matted together, having never been pruned. The trunks and branches of the trees are 68 covered with rough scales of bark, and where branches have been cut away the stubs remain, with irregular cut ends, the branches hav- ing been hacked off with an ax. These stubs have in many places cracked and begun to decay, thus making excellent places in which tne larve of the codling moth could spin their cocoons and hibernate. The writer once secured 20 larve from the holes and cracks in one of these stubs. The cut ends were not given proper Cressing and decay has taken place, often leaving large holes in the trunks and branches. Many cocoons can be found in this rotten wood, and on all the trunks and branches one can find numerous empty pupal skins from which moths have emerged. The soil of the orchard has received no cultiva- tion and is covered partly with weeds, principally prickly lettuce. The orchard is very productive and always bears a good quantity of fruit, but, being undersized and from 90 to 98 per cent infested by the codling moth, practically no revenue has been derived from it for the past five or. six years. In 1900, 1901, and 1902 the writer searched carefully for uninfested fruit, and each time found on the tree near the trunk only a dozen or so small stunted apples which had escaped the codling moth. Other insect pests are present in this orchard, each requiring special treatment. The eastern orchard is situated ina good horticultural region. The trees number about 300, and are probably about twenty-five years old. They are placed 40 feet apart, and have made a good growth. The trees have received some pruning, but as in the western orchard there are many stubs left, and there are numerous decayed holes in the trunks and branches. In many trees the branches are matted together and shade the fruit. The soil isin fairly good condition and lightly sodded. Until the past two or three years the orchatd has been remarkable for its productiveness, but a large percentage of the fruit was small and much the larger part of it was infested with the larvee of the codling moth. The treatment that these orchards should receive to bring the cod- ling moth under control is about the same. It may be stated that if the preventive measures advised for a young orchard had been faith- fully and intelligently carried out many of the existing conditions would not have been present. TREATMENT OF OLD ORCHARDS. The first thing to be done to old orchards is to prune the trees in such a manner that the sunlight and spraying solutions will have easy access to the foliage and fruit. Every other tree in the western orchard should be cut down. The stubs of branches should be sawed off close to the trunks and burned in order to destroy the hibernating larvee contained in them, and the cut ends remaining on the tree cov- ered with shellac varnish or grafting wax. The holes in the trunks 69 and branches should be filled with cement, plaster, or clay, in order that the insects inside may be confined and die, and that.other larve later in the season will be unable to enter to spin their cocoons. The rough bark on the trunks and branches should be scraped away and burned. . In both of these orchards it is a noticeable fact that the woodpeckers have been very efficient in digging out the hibernating larve. (PI. VIII.) It has been often noted by authors that early in the spring it is almost impossible to find larve of the codling moth under the rough bark and other exposed places in badly infested orchards. Instead of finding the cocoons with the larve inside, one will find empty cocoons with a hole through the bark of the tree, showing that the insect has fallen prey to woodpeckers. All places in which the Jarye might spin cocoons should be destroyed or rendered unsuitable, and the larvee forced to spin cocoons in exposed places where the wood- peckers and other birds can get them. : The soil in these two orchards should receive about the same treat- ment, except that irrigation should be begun in the western orchard. They should both receive a very shallow cultivation for about one year, with a dressing of manure. The cultivation should be so shal- low as not to injure any of the roots, which may be quite near the surface. The second year, red clover, cowpeas, or some other legu- minous cover crop should be sown, and every third year this may be turned under, thus adding available plant food to the soil. When these methods are followed the recommendation given for an orchard in bearing should be adopted. At best the preventive measures can not control the insect in an orchard, but they are valuable adjuncts which render the measures more efficient. REMEDIAL MEASURES. Remedial measures against the codling moth are those measures from which little or no benefit is derived except in saving fruit from the ravages of the insect by killing it. MEASURES OF LITTLE OR NO VALUE. The codling moth seems to have been common in orchards for many centuries, but no one made any suggestions as to how its ravages might be checked. The first recommendations made were of no value, and it is interesting to note how these recommendations have recurred at various periods in popular writings. Many of these remedies, having little or no value, are taken up by companies, given all the benefit of modern advertising methods, and thoroughly distributed before the fruit growers become aware of their worthlessness. In order that the fruit grower may know what not to do as well as what he 70 should do, a number of the more prominent of these inefficient methods are briefly discussed. It has often been recommended that moth balls be hung in the trees in order to keep the moths away. If there were any virtue in this remedy, so many of the moth balis would have to be hung on each tree, to do the work, that the expense would render it valueless. Smudging the orchard, or burning ill-smelling compounds so that the fumes will pass through the trees, has been practiced to some extent. The theory is that the moths will be kept away by the fumes and go to other orchards to deposit their eggs. It is quite evident that as soon as these fumes are blown out of the orchard the moths will return if they have left, and in order to produce any results it will be necessary that the smudge be continued practically throughout the season. Plugging trees with sulphur or other compounds and plugging the roots with calomel have been practiced to some extent, on the theory that the sulphur or calomel will be taken up by the sap, distributed through the tree, and prove distasteful or poisonous to the insect. Trustworthy scientific experiments have been carried on which show that it is absolutely impossible for the tree to take up any amount of these substances, and little or no effect upon the insects results. The writer has found several orchards in which the trees were banded with tarred paper, the evident intention being to keep the larvee from getting up into the trees. Knowing the habits of the inscct when in its larval form, we can see that this method is ridiculous, and instead of being a detriment it is a positive aid to the insect; in many cases larve were found which had spun cocoons under the bands, which formed a place in which they were comparatively free from the attacks of their enemies. There seems to be a popular idea among many farmers and fruit growers that all insects are attracted to light. Based upon this idea, there have been many recommendations to keep fires burning in the orchards, or to arrange some sort of a trap lantern by which the insects are to be attracted to the lights and fall into water on which is a film of kerosene and thus be killed. This scheme of trap lanterns was exploded many years ago, but it seems that at intervals somebody revives it, and its fallacy must be exposed afresh. By carefully experimenting with trap lanterns and determining the catch as accu- rately as possible it is found that the majority of the insects caught are either decidedly beneficial varieties, or are males, or females which have already deposited their eggs, and that but few injurious insects are caught, and none in any great number. Probably the most exten- sive experiments with trap lanterns were those conducted by Professor Slingerland. Among 13,000 insects he was not able to recognize a single codling moth. This is the usual result of all these experiments, Ch and we can say without any hesitancy whatever that the farmer who uses these trap lanterns or tries to experiment with them is simply wasting his timeand money, as the method has been thoroughly proven ineffective. It is also the practice to some extent to put cans or bottles contain- ing molasses, cider, vinegar, or some other substance of similar nature in the orchard, and upon finding that insects are attracted by these compounds and killed, many fruit growers think this is a good remedy for the codling moth. The results of many careful experiments show that only incidental captures of the codling moth are made. With both these last two practices—that is, trap lanterns and baiting the moths— the greatest trouble has been that the fruit growers are not acquainted with the codling moth in its early stages. Any fruit grower can breed moths for himself, and by comparing his catch can very easily satisfy himself. Many times fruit growers have tried spraying their orchards with ill-smelling compounds with but little success. These compounds are always more or less expensive and have never been so efficient as to justify their use. Other fruit growers think that spraying the orchard with water frequently will give relief from the attacks of the codling moth. Undoubtedly if the trees were kept in a spray all the time, the fruit would be clear of the insect; but if this were done, the probabilities are that no fruit would set, and if any should set it would not ripen well, and the trees themselves would probably die. The expense of this operation would be many times greater than that of spraying. It has been stated that electric lights repel the moth and that trees near electric lights in cities are often free from its work. The writer had an excellent opportunity to investigate this point, and found that an apple tree about 40 feet from an electric light was as badly infested as any other in that vicinity. ‘ In order to do away with the labor entailed by using bands around the trees many kinds of traps have been invented. Riley, by careful experiments, showed that one of these traps would not catch as many larve as the bands; and other experiments have shown that these patent traps are never very efficient. It was claimed for some time that the flowers of plants of the genus Physianthus might be efficient against this insect, since in order to reach the honey of the flower the proboscis would have to be passed through a narrow cleft, from which it could not be withdrawn, and the moth would therefore be held a prisoner until it died. It was proposed to train the vines around the trunks and branches of the trees, and, the moths being captured, the orchard would be protected. Conclusive evidence has been recorded which shows that these flowers have no attraction for the codling moth. 12 It has been suggested that the codling moth might be controlled by bacterial and fungous diseases. From the facts that the insect leads such a protected life and that fungi and bacteria have given so few positive results in this connection it is almost useless, with our present knowledge, to even theorize upon the value of these agencies. In general it may be stated that entomologists have at all times tried experiments with these different plans and are unanimous in their conclusions. If anything new and eflicient is ever perfected by which this insect may be more easily controlled, no doubt entomolo- gists will be its first advocates. MEASURES OF VALUE. By taking into consideration all the habits and variations of habits of the codling moth in its different stages we find that, like other insects, there are certain stages in its life history in which it is more amenable to remedial measures than at others. We find that it can be best attacked in the larval stage, although some experiments indicate that something can be done when it is in the egg stage. Cook found that by spraying an apple tree weekly from May 15 until the end of June with a strong soap solution he succeeded in preventing the infesta- tion of a single apple by the larve. In laboratory experiments with kerosene emulsion Card secured good results against the eggs. Gillette also obtained good results with kerosene emulsion. The results of these experiments have never been put to practical use for many rea- sons. The kerosene emulsion would probably be so strong, in order to have any effect on the egg, that it might injure the tree. The kerosene would evaporate quickly, and thus its effect would be for but a short time. The expensiveness of .kerosene in the West, and the number of times the.spraying would have to be made to be efficient, would prohibit the adoption of this method. The insect can be more easily attacked, at less expense and with greater effectiveness, in the larval stage. MEASURES USED AGAINST THE LARVA. The remedial measures used against the larva vary according to whether they are used after it has been hatched and before or while it is entering the apple or after it has completed its growth and left the fruit. The greater effectiveness is secured by the use of arsenical sprays before the larva has entered the fruit. The effectiveness of these arsenical sprays against the codling moth was discovered by accident in 1872. Le Baron recommended the spraying of trees with Paris green to check the ravages of the cankerworm, which recom- mendation was adopted in many orchards with great success. Profes- sor Slingerland states that the credit of this discovery belongs to Mr. E. P. Haynes and Mr. J. 8. Woodward, who found that spraying with 73 Paris green not only rid the orchard of cankerworms, but that the apples on the sprayed part were much less affected by the codling moth. It seems that other people used Paris green for cankerworms in Iowa, but there are no indications that they were alive to the fact that at the same time they were checking the codling moth. Prof. A. J. Cook, of Michigan, took up the idea and by a series of careful experiments clearly showed that the treatment was very effective against the codling moth. Forbes, Goff, and numerous others have at various times carried on spraying experiments with arsenicals, with results that show this to be the most effective and cheapest remedial measure that can be used. g SPRAYING. Spraying with arsenicals may be defined as putting a coat of any arsenical poison on the foliage and fruit of a tree, so that when the insects eat the foliage or enter the apples they eat some of this poison in their first few meals and are killed. Since the beginning of the practice of spraying there have been many important improvements in both spraying machinery and spraying solutions, which have ren- dered the process much easier than when primitive methods were in vogue. SPRAYING MACHINERY, There are as many kinds of spraying machinery as there are condi- tions to be met in spraying operations. There are certain spraying outfits devised especially for orchard work, varying from the common bucket pump to rather complicated machinery driven by gasoline engines. For a small home orchard or for an orchard of a thousand trees or less the writer would advise the use of a hand-power outfit. The capacity and cost will depend primarily upon the size of the orchard, the size of the trees, and the rapidity with which it is desired to spray the orchard. There are many excellent types of spray pumps on the market, and no mistake can be made in selecting any of the outfits of the better manufacturers, but there are several points which should be insisted upon. The interior fittings of the pump should be of brass and should be arranged so that the inside of the cylinder can be easily reached in order that repairs may be made. The air cham- ber, which insures a steadier stream and acts as a reservoir of force, is almost a necessity. A pressure gauge upon this air chamber will be of great value, as it will aid the man who does the pumping to keep the pressure at about the same point. The pump may be mounted upon a barrel, which may be stood on end or put on the side, or it may be mounted on a tank or upon the wagon frame on which the tank is mounted. These tanks are preferably of wood, and should be of very strong construction and securely bolted together with iron rods. Screens should be used to strain out particles which would clog 74 - the nozzles, and should be used both as the water is put into the tank and as it is pumped out. It is highly essential that some mechanical device be used to keep the liquid in agitation so that the coarser par- ticles will not settle to the bottom of the tank and render the mixture of variable strength, especially if Paris green is used. The hose may be any of the types in use, and a hose extension of some light tube, covered preferably with bamboo, should be used in order that the tops of the tall trees may be easily reached. 22.0. 3 Pm tee oe emeesae eens pounds... 4 WILE TS ps olor She Sia way din cece, SR ne tere ee gallons. = i The ingredients are boiled in the required amount of water until dissolved, which will take place in a comparatively few minutes, after which the water lost by evaporation is replaced. To every 40 or 50 gallons of water a pint of this stock solution and from 2 to 4 pounds of fresh slaked lime are added. The chemical compound derived from the combination of the sal soda and the white arsenic is arsenite of soda. In the presence of lime this breaks down and arsenite of lime is formed. It requires 4.4 pounds of crystal sal soda or 1.6 pounds of dry sal soda to combine with 1 pound of arsenic and 2 pounds of freshly slaked lime to combine with 1 pound of arsenic to form arse- nite of lime. It is always desirable to have an excess of lime present, in order to prevent all danger of burning; furthermore, this excess is a convenience to the fruit growers, because they can see by the distri- bution and amount of lime on the foliage how well the spraying has been done. This formula, which is the Kedzie formula, with a very few minor changes, has been used in many different sections of the country with unvarying success. In all of the practical tests under the advice of the writer this solution is used, and is found to be not only as efficient as other solutions, but far cheaper. Arsenate of lead. Arsen atevOlsOGais s. ke Mien nee ee ee gee Seen ee ounces. .” 10 Acetate ob lead: 2 faster aes SANE Sy Me eee dose 24 Wich <= 5 eat eat Am Deel a, oe 8 Pe eee A gee gee gallons.. 150 to 200 The arsenate of soda and acetate of lead should be dissolved sepa- rately and then poured into a tank containing the required amount of water. These chemicals unite readily, forming a white flocculent pre- cipitate of lead arsenate, which is easily kept in suspension, and can be used in excessive strengths on delicate plants without the addition of lime. When sprayed upon the foliage it forms a filmy, adhering coat, which is but little affected by ordinary rains. There are several good preparations of lead arsenate upon the market. Some of these are prepared in a wet state, others in a dry or powdered form. The moist preparations are much preferable, because the dry powder does not give such a good coat of poison upon the foliage. This poison has given excellent results in use against the codling moth, but on account of its expense it is comparatively little used. If it is desired to use Bordeaux mixture with any of these solutions the arsenicals are added to the Bordeaux mixture in the same propor- tions as they would be to a similar quantity of water. At all times the greatest care should be taken to prevent accidental poisoning with 83 these compounds.* The fact should be firmly impressed upon all those who have anything to do with these solutions that they are of the most poisonous nature. All packages, boxes, or bottles containing the materials should be plainly labeled and kept in secure places which can be locked. The utensils in which the mixtures are prepared should be thoroughly cleansed or kept in some secure place, so that no mis- take can occur in using them for other purposes. COST OF SPRAYING. The cost of spraying is so small when compared with the benefits to be obtained that we can say it is the very best investment the grower can make. As with other farming operations, the first year will be more expensive than succeeding years, as by experience the fruit grower will be able to reduce expense considerably without impairing efficiency. It is a very difficult task to estimate the cost of spraying, for many factors enter into the problem. The initial cost of the outfit varies from $15 to $75 for hand-power outfits and from $260 to $275 for gasoline outfits. These outfits can be used for many years, and the parts of the gasoline outfit can be used for other purposes. The cost for spraying material amounts to little. The cost of the different spraying materials will vary with the different sections of the country, according to the freight rates and the quantities purchased by fruit growers. Where a large amount of @ Although no accidents are known to have occurred from the use of arsenicals in spraying, it is well to know what to do in case of accidental poisoning. If evil effects are noted in the case of persons who constantly handle these poisons, a physi- cian should be consulted. If by any mistake or carelessness a small quantity is swal- lowed, an antidote should be employed without delay. The following extract in regard to antidotes for arsenic poisoning is taken from Poisons: Their Effect and Detection, by A. W. Blyth: ‘“‘TIn any case where there is opportunity for immediate treatment, ferric hydrate should be administered as an antidote. This converts the soluble arsenic acid into the insoluble ferric arsenate, the ferric oxid being reduced to ferrous oxid. It is neces- sary to use ferric hydrate recently prepared, for if dried it changes into an oxyhydrate, or even if kept under water the same change occurs, so that after four months the power of the moist mass is reduced to one-half and after five months to one-fourth. When once the poison has been removed from the stomach by absorption into the tissues the administration of the hydrate is absolutely useless. ‘Ferric hydrate is prepared by adding streng ammonia to the solution or tincture of ferric chlorid found in every chemist’s shop, care being taken to add no excess of caustic ammonia.’’ Lime water may also be used as an antidote, but it is not so effective as ferric hydrate. It is understood that after the antidote some emetic, such as mustard or warm water, should be administered immediately. Persons who use great quan- tities of arsenites in spraying, and who are some distance from drug stores, are advised to keep a small bottle of each of the chemicals named to use in making the ferric hydrate. In preparing ferric hydrate continue to add the ammonia until, after being well shaken, a faint odor of ammonia can be obseryed, 84 arsenites is used it is advised that they be purchased in 100-pound lots, using 600 gallons of spraying solution asa basis. Taking the prices of these different compounds as they are in the Far West, the following estimates are made: Paris green: Panis.ereen, 4 pounds; at 2 cents) a. 22 se 2 eee mee $1. 00 Lame, ‘Si poundsiss o-5oe ee Roe se cee oe aR ae Oe yee . O4 Totalvces 2. co eee a eee ee eee 1. 04 Scheele’s green: Scheele’s green, 4,pounds, at 123 cents...-........-.-..-.-- 50 Linme;"Sipoundsy22 5 52 Des At eS eee Saeeeee e a eee . O04 TE Pell tact teas SA ee a Se RE EE OY eon en en ap mn 54 Lime arsenite: : White. arsenic, 14.pounds, at 1O.cents..22555-.-2-.252.4-c8- .15 Im es4 3 OUMES SE. 2k ae eee y ess Nel ney et ne ae .015 ANeloliqavayney lthwanves, IP} jovomaOles kee seed sos odo oseeub Soe ee . 06 Totaleso 6 be to ee Saye ens |e Se ee Re eee 22D Lime arsenite with soda: White arsenic, 13 pounds, at 10 cents.......--..-.---- 2 ee SalSod as sOumoUma siwartel ls ccOm tS) eer ee eet eee mee . 09 No koltinvesauulubtonve (5) joyous. Se SUL senor ec Gan bsoecl ae socese 08 ORAS Fees cick te Be tae WP ee ee See te ce Sage Ea Lead arsenate: Arsenate of soda, 24 pounds, at 10 cents.......-..--------- . 25 Acetate.ob lead, 6 pounds) at 2 centse S22 55-45 s5 eee .&2 Potala ee ce IS) ee re ae oe oes She eee 97 Prepared lead arsenate, 36 pounds, at 20 cents-...--------- 7. 20 From the foregoing quotations, any fruit grower can estimate the expense of spraying by changing the prices to those prevailing in his vicinity. The prices of these chemicals, excepting the lime and sal soda, are from about 2 to 5 cents per pound more in the West than in the East. The labor of preparing, which is but little, is another factor which must be included. In the preparation of arsenicals for a home orchard or a small commercial orchard it may be advisable for the fruit grower to purchase the more easily prepared compounds, such as Paris green or prepared lead arsenate, as this does away with much trouble and loss of time in preparing the solution. Labor is the principal element of cost in actual spraying operations. The cost of one spraying for a thousand 8-year-old trees in the far West, using 24 gallons of lime arsenite and soda compound per tree, is estimated as follows: — 85 Hand-power outfit: Many snditeamy 4 @ivs,abmo-00) 2 coo feces s ccc ken ng orm otc 8 $14. 00 Two men 4 days, at $1.00 each-2. 22202. 2245222202. ee 22 -e 12. 00 AV RETUEUIS ert oe ere rae ere eae, SS, farts sims ARE Ste as Ie aby Ota eee te ea Moet ee eae Sarasa oes see ome 27.12 Gasoline-power outfit: Man anid team by aaye ai do100 seats ok ce ccssce hace ke 5. 25 Onermantaadaysat pleo0 nos. 6 oe a SS Sete see cee bes 0) OS AY TEEN ey TC S| Ss Bn kal ea ee i pe ge ital iraniiorel We PANO eT Sey it foe ord stu e cus Gee ees 55 SNOT Sat ee cas he eee tees tes EA Ch ie ney 2 ee Se So hei iyi The above estimates are taken from actual conditions in the field, and the prices of material and labor are based upon current rates in the far West, where they are considerably less than in the East. It is assumed that the men and teams were employed at the local rates; but as men and teams are already employed upon fruit farms, the actual expense of these spraying operations is much smaller. Accord- ing to these estimates one spraying would cost 2.7 cents per tree if a hand-power outfit is used, or 0.9 cents per tree if a gasoline-power outfit is used. The additional cost to the fruit grower would be much less than this, and in some cases would probably not amount to more than 1 cent per tree with the hand-power outfit, or one-half cent per tree with the gasoline outfit. TIME AND FREQUENCY OF APPLICATION OF SPRAY. The time of application of the spray is one of the most important con- siderations in the work. It has been found that in many sections of the country fruit growers have sprayed without any definite knowledge as to when the spray would be effective, and many times it was not at all so, the effectiveness that it had depending more upon chance than anything else. Other growers follow the empirical rule of spraying once every two weeks after the blossoms have fallen. If this rule is followed no doubt many of the sprayings during the season have little or no effect upon the codling moth. It can be readily seen that to be effective the poison must be placed upon the trees so that when the larvee are hatching they will get some of the poison; but if they are already inside the apples or in their cocoons they suffer very little from the spraying. Hence we find that where there are but two genera- tions of the insect there are only two periods in the season when a large proportion can be affected by the poison, and these are the proper times for spraying. The work done at these two periods may be termed the early and the late snrayings, the early spraying being directed against the first gemeration of the codling moth. Two sprayings at the early period are advised, one a few days after the blossoms have fallen and before the calyx closes, and the other 86 about two weeks later, when the majority of the larve are entering the fruit. There has been much discussion recently in regard to dis- pensing with the spraying immediately after the blossoms have fallen. It has been found that the larve enter the fruit from one to two months after the blossoms have fallen. In cases of bad infestation, where preventive measures have been neglected, or there is an abun- dance of the insect, it might be well to make three sprayings while the second generation is entering the fruit. This period varies with the locality and with the seasons in the same locality; but there are a few methods by which the time can be approximated with sufficient accu- racy, and in view of the fact that the time is variable the writer does not wish to recommend that the spraying be dispensed with until each locality is studied. Spraying may be begun immediately after the first new entrance holes of the second generation are found, or about twenty days after the date the maximum of the first-generation larvee are found under the bands ready to spin their cocoons. The larvee of the second generation in southern Idaho usually begin to enter the fruit the last week in July, but the majority enter in August, and but few in September. The number of sprayings to be made against this generation depends entirely upon the success achieved against the first generation. It has been found quite definitely that the injury due to the second generation is much greater than that from the first gen- eration; and if the injury due to the first generation is from 2 to 5 per cent the writer advises a third spraying for the second generation; but if the injury has been only 1 per cent or less, two sprayings will be found sufficient. The quantity of lime used in these late sprayings should be reduced to a minimum, as lime on the fruit depreciates its market value. Light showers wash but little of the spray from the tree; but if there is a heavy shower or continued rain, a large amount will be removed, and it will be necessary to repeat the spraying’s as soon as possible. Lead arsenate is less affected by rain than the other spray- ing compounds. HOW THE POISON KILLS THE INSECTS. Though Paris green has been used for spraying purposes for many years with success against the codling moth, it is only recently that any serious effort has been made to ascertain how the poison is obtained by the larve. Slingerland was the first to answer this ques- tion with any degree of accuracy. According to him the spray lodges in the saucer-like calyx when the young fruit is erect after the blos- soms have fallen, and upon the segments or leaves of the calyx clos- ing the poison is held there for some time. As about 80 per cent of the larvee of the first generation enter the fruit through the calyx, it is easily seen how the majority of them would obtain some poison. 87 Calyces were analyzed and the poison found in them, showing that the closing of the lobes incloses some poison at least two weeks after the spraying has been done. The writer is unable to find any pub- lished record of any larve having been found in a calyx, which were killed or supposed to have been killed by the poison. The evidence which goes to show that they are killed is all indirect. In Idaho in 1902 the writer gave special attention to this most difficult point. By examining the apples immediately after the blossom had fallen it was found that the calyx proper consisted of two parts; first, the calyx tube, which we may say is on the interior of the apple, and then the lobes or bases of the lobes which support the stamens. The stamens stand close together and form a sort of roof over the calyx tube. The writer has many times cut open this calyx tube after spraying has been done, and was unable at any time to distinguish any particles of spray inside the tube. The writer is also unable to give any definite figures as to what percentage of the larve enter the appie by way of the calyx tube, but it is possible that it is large. The differ- ence in percentages of larvee which have entered the calyx on sprayed or unsprayed trees should indicate the efficiency of the spray. Table III gives 82 per cent as entering the calyx on sprayed trees and 80 per cent on unsprayed trees. There was lack of data in regard to the sprayed trees, which was not discovered until it was too late to obtain a new series. Cordley finds that the larve do not enter the fruit until two months after the petals have fallen, and on that account does not recommend the spraying immediately after the blossoms have fallen. How the larvee of the second generation are killed is a question still in a somewhat chaotic state. It is generally believed that the larve get the poison when they enter the fruit, but the observations of many investigators, including the writer, show that when the larve are entering they eat little or none of the fruit. In both sprwyed and unsprayed orchards it is quite common to find places where they have entered the fruit and have died shortly after entering. Counting on 426 new entrance holes in sprayed trees showed that there was an average of 40 per cent of the holes in which the larve had died, and in two counts this percentage went as high as 70. Other countings on unsprayed trees gave, out of 606 new entrances, 11 per cent in which the larvee had died. As there is no way of knowing accurately how many of these holes were caused by larvee which entered the fruits where two apples touched, these data can not be relied upon, but the writer believes that during the period in which the entrance holes were made at least 10 or 15 per cent of the larvee succumbed to the spray. Twice larve were found dead before they had entered the fruit. Many times early in the season holes were found, the making 88 of which would employ the larvee for several days. In these cases it is questionable whether or not the spray killed the insects. In regard to the entrance of the second generation, the larve: may get some of the poison when their jaws are slipping on the fruit in the attempt to make an entrance, but at best the percentage probably killed in entering the fruit can in no way account for the general efli- ciency of spraying. Considering the egg-laying habits and the leaf- feeding habits of the larve of both generations, the writer is strongly of the opinion that by far the larger number of the larve killed by spray are killed through eating or nibbling the poisoned leaves before they find fruits. It is to be hoped that future years will develop more definite data on this subject. THE BANDING SYSTEM. As before indicated, upon leaving the fruit the larva seeks some place in the crevices or loose bark in which to spin its cocoon. This fact was known as early as 1746, but it was not until 1840 that Bur- relle, of Massachusetts, discovered that by winding something around the tree or placing cloth in a crotch many larvee would be induced to collect there and could then be destroyed. He recommended destroy- ing themin a hot oven. The banding system was further studied and elaborated by Dr. Trimble, who recommended hay ropes for bands. Very soon this became the most successful method used, and up to about 1880, by its use many fruit growers were able to save consider- ably more of their fruit than before. Many other observers have made studies of these bands and proved what was best in the way of material and the manner and time of application, until now it is one of the very best adjunct methods in the control of the codling moth. Generally speaking, the system of banding is simply furnishing the larva a good place in which to spin its cocoon and killing it after it has done so. (See Pl. X.) The materials used for these bands may be designated as temporary and permanent. The temporary bands are composed of hay, paper, or any other cheap material, and, after the larvee have entered the bands, are burned with the contained larve. Permanent bands are usually of cloth; these, after the larve are killed, are replaced on the tree. The materials for these bands are various, and it has been found that the most efficient is some dark, heavy material. Bands of thin muslin are quite inefficient. Professor Aldrich recommends brown canton flannel. In orchard practice it is found that fruit growers use almost any material, such as old clothes, burlap, and canvas. One of the most essential features of the banding system is to render all other places on the tree unsuitable for the spinning of the cocoon, thus leaving the band the only alternative. Cracks in the tree should be filled, the rough bark scraped away, and all other obstacles removed. 89 The band should consist of a piece of cloth long enough to go around the tree more than once, and from 10 to 14 inches in width. This piece of cloth is folded once lengthwise and placed around the tree. There are many devices for holding the bands in place upon the tree. The one which gives the most satisfaction, and allows the band to be removed and replaced most readily, consists of driving a small nail through the ends of the band after wrapping it around the tree, and then nipping off the head of the nail in such a manner as to leave a sharp point. Subsequent removal of the band is accomplished by simply Yi Vy; i POU, / OP, 7 {i | VG i a)" ik \ 7) FT| T OANA NAA, Mi (ys WZ | WZ! ) i Fig. 19.—Apple tree banded, Fic. 18.—Large apple tree properly banded for the codling moth showing bands both above (original). and below a hole in the trunk (original). pulling the ends off the nail, and replacement by pushing them down again over it. Ordinarily one band to the tree is sufficient in general orchard practice, but in cases where the trees are large and havea number of large branches, it is advisable to put one band around the trunk and one around each of the larger limbs. (Fig. 18.) Where there are holes in the trees which can not be rendered unsuitable for the spinning of the cocoons, it is the best to put bands both above and below them. (Fig. 19.) 90 Many writers have experimented upon the effect of several bands upon the tree. LeBaron gives the following table: Taste VIII.—Number of larve caught under bands. Date of examination. a July 28. | Aug. 11.) Aug. 25.| Sept. 9. | Sept. 23. BandsonwWim Ds: e525 ae bles ooo ee eee 43 31 7 9 Middle bands -233 8 sees el eae See 83 13 15 39 22 Lo westibandsiet a2. Coe ae eee eae peer 94 pL 24 33 28 On a single tree, from July 4 to July 23, the same writer found 110 larvee under the top band and 150 under the lower band. The author states that the windfalls in every case were left as they fell. In the season of the year when a large number of the wormy apples were on the ground the lower band caught most of the larve, while during July, when the windfalls caused by the first generation had hardly begun to fall, the larger number of larve were caught by the upper band. Professor Aldrich experimented upon one large tree and five bands. The table made from these experiments is here given. TaBLeE IX.—Professor Aldrich’s record of bands on one tree. July— August— Pepa r— October— = Fal ae | 7. | 15. | 21. | 30. 62 Ss D6 aleeden iOS (elon || etal eal otys | nes ie POD eee): ate tee une Soe eo ee [2] TOSS) | tet OT ee TalenSsa aaa e ZHAO |-20 ye ts 156 Seconderen fees : eee eS et Osh yh On ADs Lh Gi abort to. latenone WA) S|" Sas 80 hinds Soe: lest 2 peed | A AS a 6s Ob 6s eeeal tes Bape ier bel (3 86 Lia iy le Soe ee Soe aes ie Ul Ba BC fn a aes 9 A ae a a FY) aa eee fl ete) Nae 75 BOtiOMIRS see se ee te Gt Seek oe (Ua 33h fees Ot Va Bose tis fal bee PS ral? | An 3 CT I Var | 3 97 AND es Sa ee e | 4 | 42 | 64 | 64 | 63 | 23 Dil Ded alates | ile 24 | 37 | 55 | 34 494 Out of a total of 494 larve about 30 per cent were caught on the upper band, and the lower band caught more than any of the inter- mediate ones. The experiment also shows that in seeking a place for their cocoons the laryz will cross several bands, and as there is no way by which those going up the tree and those going down can be separated, no exact percentages of such can be given. Wickson found by carefully conducted experiments that while 2,704 apples and pears were counted from which larve had escaped, there were only 1,188 under the bands, or 44 per cent. The remaining 56 per cent either found other places in which to spin their cocoons or were destroyed by their enemies. The percentage of larve caught upon a tree will depend entirely on the condition of the tree. If the tree is free from cracks, holes, and rough bark, more larvee will be caught; while if there are other places in which they can spin, fewer of them will go under the bands. It has been fully demonstrated that in badly infested orchards of the West only a comparativ ey, small percentage of the fruit can be saved by bands alone. 91 After the larve have collected under the bands they must be killed or the bands will become a positive aid to the insect. The usual method of examining the bands: is as follows: One end is removed from the nail and rolled back upon itself around the tree. As the cocoons, larve, and pup are exposed they are cut in two with a sharp knife or crushed: Many methods have been devised by which these bands can be collected in wagons and brought to a central place, where they are put in hot water, run through wringers, or some other device used to kill the larvee; but in view of the fact that many of the worms will crawl out in transit, and comparatively few of them remain attached to the bands, these methods must give way to the one described. Another important point is the length of time which should intervene between the examination of bands and the killing of the larve. This time depends entirely upon the length of time which it takes the larva to emerge as a moth after having left the fruit. In the warmer sections of the West 6 or 7 days has been recommended. By extensive experiments carried on by Professor Gillette and the writer it was found that practically none of the moths issue until after 11 days from the time they entered the bands. The data upon which the recommendation of 6 or 7 days was based have in some cases been found to be quite inaccurate. When the trees were exam- ined not all of the larve were killed, and the second week afterwards some of them were found to have emerged, and from this the conclu- sion was reached that some of them went through the cocoon stage in 6 or 7 days. The experiments by the writer and Professor Gillette have been found in practice to allow a small number of moths to escape. A person examining bands frequently can easily tell whether the time is too short or too long. If the time is too long, many empty pupa cases will be found projecting from the band, whereas if the time is too short most of the insects will be found in the larval stage, not having had time to transform to pupe. EXPENSE OF BANDING. When compared with the cost of spraying, banding is comparatively expensive. One man can examine the bands and kill the larve on about 300 trees in one day. Counting his wages at $1.50 per day, we find that it costs about $5 a thousand trees for one examination, which is about half the cost of one spraying. The bands should be placed upon the trees in the spring at about the time the earliest larve of the first generation begin to leave the fruit. This time is usually about two weeks after the first wormy fruits have been noted, and in south- ern Idaho is about June 15. It is always well to apply the bands a week or so earlier than there is any necessity for. The bands should be examined every ten days and the larve which have collected in them killed. This makes about ten or eleven examinations of the bands in the course of the season. Examination after the first week 92 in September is unnecessary in southern Idaho and practically all of the Pacific northwest, as very few moths emerge after this time. After the fruit has been picked and carried off, the bands should be removed, all the larve in them or on the trees killed, and the bands stored, because if they are left in the orchard they will soon rot. WHEN BANDS MAY BE USED. Bands may be used to great advantage in an orchard bearing its first crop, which is but little infested. Many growers whose orchards are more or less isolated and but little infested use the banding system as a means of control. One of these is Mr. I. B. Perrine, of Blue Lake, Idaho, who has had great success in keeping the injury in the worst infested section of his orchard down to less than 3 per cent. The most important use of the bands is as an adjunct to spraying in a badly infested orchard when it is desired to bring the codling moth under control in that orchard, or in general practice when the trees are large and the spraying can not be well done on account of either the inefficiency of the spraying machine or the height of the trees. However, the writer, by many extensive experiments, has clearly demonstrated that when four or five sprayings are made with the gasoline power outfit, and the spraying solution is thoroughly applied at the right time, banding is unnecessary. In orchards where spray- ing is the only remedial measure used it is advisable to keep bands on four or five normal trees, killing the larve at stated intervals and recording the results, so that the band record may act as an indicator for the conditions in the orchard. PRACTICAL TESTS. The season’s work in 1900 may be summed up in saying that the work accomplished simply outlined the problem of the codling moth in the Pacific northwest. In 1901 the apple crop was so unusually small that all practical tests which had been begun were abandoned, and the time devoted to a study of the life history of the insect and planning a campaign for the following year. It was decided to give the recommendations of previous years a thorough practical test under actual field conditions from the fruit grower’s standpoint. Some dif- ficulty was experienced in obtaining orchards in which to work. Keeping in view the idea that the codling moth is the greatest injuri- ous factor in the commercial orchard, a large amount of work was done in such orchards, the principal part in the orchard of the Wilson Fruit Company, near Boise, Idaho, through the kindness of Hon. Edgar Wilson, and in that of Mr. Fremont Wood. Mr. McPherson’s orchard and that of Mr. David Geckler were visited frequently and observations made. There were many orchards in various localities in which no measures were used against the codling moth, and these were used as checks upon the sprayed orchards. In Idaho the injury 93 by the codling moth in 1902 was quite variable, as there had been but a scattering fruit crop the year before, and consequently a lack of insects in some localittes. The orchard of the Wilson Fruit Company, which is a type of the very best commercial orchards in Idaho, was planted in 1894 by Hon. Edgar Wilson, and was sold by him to the company which is the pres- ent owner in the early spring of 1902. Mr. Wilson acted as manager for the orchard company for the season, aided by Mr. W. F. Cash. This orchard consists of 650 Ben Davis trees, 500 Jonathan, 750 Rome Beauty, 141 Northern Spy, and 800 trees which were planted as Wolf River, but were subsequently budded to Jonathan, and have not yet come to bearing. There are three short rows of Pewaukee, and a few trees of other varieties scattered throughout the orchard. The house in which the apples were packed and the culls stored in the fall of 1901 is about 200 feet from the orchard and has always been a source of infection for it. (PL IV, figs. 2and 3.) Early in the season of 1902 Mr. Wilson purchased a gasoline-power spray outfit and prepared to give the orchard a thorough spraying. The improvements made by Mr. Wilson and Mr. Cash have rendered this machine one of the most efficient for this purpose. A single spraying was accom- plished in about four days, using lime arsenite with soda exclusively as a spraying solution. About 2,000 very heavily loaded trees were in bearing. The conditions of the previous season were such that there was an abundant supply of insects present in 1902, except in the Rome Beauty section. The writer estimated in 1901 that from 40 to 60 per cent of the fruit in the Jonathan and Ben Davis sections was infested, no late spraying having been made; and the small amount of fruit in the Rome Beauty section was all infested. No bands were used, except upon the trees left unsprayed and a very few near the apple house. The blossoms of the Jonathan and Ben Davis were fully open about May 10, and had dropped about May 20. The Rome Beauty blooms through a longer period of time, and some blossoms were observedas late as June 1. Spraying should have begun about May 19, but on account of continued rains it was delayed until the 23d, at which time the orchard was given a thorough spray- ing. After two weeks the orchard was again sprayed, at about the time the first larve were beginning to enter the fruit. By the Ist of July about all of the larve of the first generation had entered the fruit. Countings on the Ben Davisand the Jonathan section gave an average of a little less than 1 per cent infested, while the Pewaukee trees, which were unsprayed, had from 20 to 26 per cent infested. The Jonathan tree nearest the apple house had about 5 per cent wormy, but this percentage decreased rapidly in the surrounding trees. Other orchards in the same condition showed from 10 to 50 per cent wormy; while orchards in which no remedial measures had been applied, and in which no insects were left over from the year before, showed a very 94 small percentage wormy. In the last week of July, at about the time the second generation was beginning to enter the fruit, a third spray- ing was made; and the fourth spraying was made about August 8, at which time-a demonstration was made to visiting fruit growers. About ten days after the spraying a dashing rain washed off a consid- erable amount of the spray. Mr. Wilson and Mr. Cash did not think it advisable to make another spray, in view of the fact that the results already secured were so satisfactory that they thought it unnecessary. There is no doubt in the mind of the writer that if this spraying had been made the results would have been better. Harvesting began about the second week in Ocio»er, at which time the final results were obtained. Many trees were selected early in the season and the wormy fruit upon them counted; but as the season progressed the number was reduced on account of the lack of time to make the proper countings. The following table is compiled from the results upon six average-sized Ben Davis trees which were situated about the center of the Ben Davis section. At all times the greatest care was exercised in making these countings as accurate as possible, every one of the apples being counted and no estimates made. TABLE X.—IJnfested and non-infested apples on six sprayed trees. anes NN sophisti eR LY RNs ee etek Total | Total ; 2 ee | | 3 Total | apples per pa eS rigs In- Free. | Total In- Free. | Total ee tae apples.| | in-_ (cent in- BEER, fested. : * | fested. ‘ ee | frosted fested. | fested. 7 | 1| July 16.... yh eee eye nN 40:: 3902) < Sa. oe ei eels ee ene 2 2 | bo Total 200 | 1,210 | 1,384 Com eseee Bl sh eee sags 1, 892 269 14 95 The large amount of free fallen apples on trees No. 1 and No. 2 are due to the apples picked off in the process of thinning. The average total per cent infested throughout the season for these trees was 15. The greatest difficulty was met with in obtaining any reliable esti- mate upon the general results from the orchard, for the reason that the larger percentage of the seconds and culls were graded as such because they were small or uncolored. The Ben Davis section pro- duced 1,944 boxes of strictly first-class fruit, and the writer estimates that this was only about one-third of the total produced. In one sec- tion of the orchard there were trees in which the loss was fully 25 per cent at harvesting time, but there were many others in which the loss was not over 5 percent. The writer estimates that at picking time about 10 per cent of the fruit in this section of the orchard was infested. In the Jonathan section 2,030 boxes of first-class fruit were packed, and the culls were estimated at 146 boxes. By numerous counts it was found that only about half of these were infested, which gives a total of 73 boxes of infested fruit. As a general result, about 3 per cent of the apples were found infested, and-the total per- centage for this section of the orchard was probably about 5. It was found that the tree nearest to the packing house was about 50 per cent wormy, but the percentage diminished rapidly toward the center of the block. A few trees which could not be well sprayed on account of their situation with regard to irrigating ditches were more wormy than others. In the Rome Beauty section, in which there was a small crop the year previous, a total of 3,017 boxes of first-class fruit was packed, and it was estimated that one-fourth, or 109 boxes, of the culls and seconds were infested, or about 3 per cent of the whole crop. The Pewaukee apples were practically 100 per cent infested at the end of the season. The apples were counted on an unsprayed Domine tree September 4, and 81 per cent were found infested. From experiences in other orchards with this insect, the writer believes that, had it not been for spraying, the fruit in this orchard would have averaged from 80 to 90 per cent infested. (See Pls. XIII, XIV, XV.) In Mr. Cash’s orchard, which is separated from the Wilson orchard only by a road, it was found that the Jonathans were 25 per cent infested, only two sprayings having been made. The orchard of Mr. Fremont Wood, which is a type of the best of the smaller commercial orchards, was kept under observation through- out the season. This orchard consists of about 1,000 trees, the larger per cent of which are Jonathan. These trees were set out about 1895. In 1901 the crop was small and was almost totally destroyed by the codling moth. In 1902 a hand-power sprayirg outfit was used (PI. XII, fig. 3), which was supplemented by banding. The sprayings were made about the same time as in the Wilson orchard, except that the last spraying was after the rain, about the middle of August, and 96 it was probably more efficient on that account. After the first genera- tion of the larve had entered the fruit, it was found that there were not over 3 to 5 wormy apples per tree. Harvesting was begun in October, and at that time it was found that in the Jonathan section, which consisted of about 900 trees, there were 4,700 boxes of first-class fruit packed. Of culls and windfalls there were about 900 boxes, of which, from numerous counts, it was estimated that about one-half, or 9 per cent of the entire crop, were infested. Mr. McPherson’s and Mr. Geckler’s orchards are types of old com- mercial orchards in which the trees are large and the infestation bad. It was only with difficulty that remedial measures could be applied efficiently, as preventive measures had been neglected. In both instances, on account of the height of the trees and their closeness, the sprays could not be well applied. Mr. Geckler estimated his loss as high as 50 per cent, while Mr. McPherson lost as high as 30 per cent on the same varieties. In both of these orchards there is a con- stant supply of insects from other orchards, and their control requires radical application of preventive and remedial measures. Mr. J. A. Fenton estimates that his crop was only about 15 per cent injured in 1902, he having used bands and spraying. Mr. I. L. Tiner, who has a small orchard in the city of Boise, estimated that he saves about 80 per cent of his fruit each year. Mr. Gus Goeldner, near Boise, estimates that he saves 90 to 95 per cent of his fruit each year. In many sections of the West estimates have been made by fruit grow- ers in which they say they save from 85 to 98 per cent of their fruit. Sometimes these estimates are obtained from countings, but more often they can not be relied upon, the fallen fruit not having been taken into consideration. The results of practical tests in these orchards show that with four or five thorough sprayings, preferably by a gasoline-power out- fit, from about 85 to 95 per cent of the fruit can be saved from the codling moth. By a series of applications of these measures even this margin of loss may be reduced; but the saving of 90 per cent of the fruit under present conditions may be considered a solution of the problem. RESUME AND CONCLUSION. The codling moth, which is now a cosmopolitan insect, was intro- duced into the Pacific northwest about 1880. On account of the warm climate two overlapping generations are produced, and if proper meas- ures of control are neglected the insect, under normal conditions, will infest practically the entire apple crop of many localities. The preventive measures are fully as important in controlling this insect as the remedial measures. MOUS ) SUT pur sotdde uate yo soxoq 1 G XOq [ 1NOqB IO syoyseq {ULIOM JO ‘sordde . "GUVHOUO NOSTIM ‘GZ ‘ON 33au_L WOYS SadddyY ANYOM GNV NV3I9 Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE XIII. oq B Jo J[RYy-9UO puR so[dde uBajo Jo soxog g SuLMOYS JOx AUIIOM 2 “{MIOM 910M PITYI-9U0 JNOGR Tory AM jnoqe pu ‘(fF “ON) dod} oY} WOAy saydde T jo ‘punois ay} wo1y so}dde Jo soxoq ‘GHYVHOYNO NOSTIM ‘bp ‘ON 3SXL WOYS S3TddY ANYOM GONV NV319 Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE XIV. é i P i en i sie ey E - : _ -¥ - y i ¢ i ' . ' € . ia - 4 thi Anal iil pi A Lit oe ee emare . b _ jet ” Bul. 41, Div. of Entomology, U. S. Dept. of Agriculture. PLATE XV. CLEAN AND WormyY APPLES FROM TREE NO. 6, WILSON ORCHARD. Showing 8 boxes of clean apples and 1 box of wormy apples from the tree, and 1 basket of clean apples and 1 basket of wormy apples from the ground. PLATE XVI. Bul. 41, Div. of Entomology, U. S. Dept of Agriculture. PREPARING APPLES FOR MARKET, ORCHARD OF HON. FREMONT Woop, BOISE, IDAHO. Jt Remedial measures which are of value have been found to be spray- ing with arsenites and banding. Spraying by the use of a gasoline- power outfit has proved to be the most effective, such spraying, using lime arsenite with soda, having reduced the injury in a certain orchard which had previously been from 40 to 60 per cent to 10 per cent. By the use of proper preventive measures, spraying and banding, for a number of years, the injury due to the codling moth can be reduced from nearly 100 per cent to 5 or 10 per cent in an orchard in any locality. BIBLIOGRAPHY OF MOST OF THE MORE IMPORTANT CONTRIBU- TIONS TO THE LITERATURE OF THE CODLING MOTH. - The following bibliography down to 1898 is practically a duplicate of that published in Professor Slingerland’s. Bulletin 142, Cornell Agricultural Experiment Station, pages 63-69: 1635. GorpAERDT. Metamorphosis Naturalis, Vol. I, p. 98, fig. 46. Apparently the first published account of the insect. It seems to have escaped notice until 1864, when Werneburg referred to it in his ‘‘ Beitrage zur Schmetterlingskunde.” Lister added nothing of importance in his Latin edition of Goedaerdt published in 1685, 1728. Frisco. Beschreibung yon Allerley Insecten in Teutschland, part 7, pp. 16-17, Pl. X, figs. 1-5. Grotesque and yet quite accurate descriptions of moth and larvze; believed it preferred to work in unhealthy or injured fruits. No definite data on life history. 1736. Reaumur. Mem. pour servir a L’Histoire des Insects, Vol. II, pp. 484, 496-499, pl. 38, figs. 11, 12, and pl. 40, figs. 1-10. Good account of work of larva in fruit and in making its cocoon. Two broods indi- cated. 1746. Roxrsev. Insecten-Belustigung, Vol. I, part 6, No. 13, pp. 33-387, pl. 13, figs. 1-5. In accuracy of detail and coloring the hand-painted figures equal, if not excel, any colored pictures of the insect published since. Good account of original observations upon its life history; thought the newly hatche | larva sometimes entered the fruit beneath the eggshell, and that the worms sometimes left one apple and Went to another fresh one. One brood indicated. All stages, except the egg, well described. 4 1747. Witxes. The English Moths and Butterflies, Book I, class 1, p. 5, no. 9, pl. 65 (copies of Roesel’s figures). Probably the first English account; brief compilation from Roesel. Gave to the insect its name of ‘‘codling moth,’’ from the codling tree, which is also figured. 1758. Linne. Systema Nature. Ed. X, p. 538, no. 270. Tinea pomonella, ‘‘Alis nebulosis postice macula rubra aurea.”’ Original description of the insect when it received its first scientific name. 1791. Brau. Insektenkalender, Vol. II, p. 465. Brief account with many earlier references. Common and sometimes destructive in orchards; and records its habits in fruit rooms. 1802. Dr Tiany. Historie Nat. des Insectes, Vol. IX, p. 256. Largely a compilation from Reaumur and Roesel. Says eggs are laid on fruit before petals fall. 1805, Brcusrein and ScHarrenperc. Natur. der Schid. Forstinsekten, Part III, pp. 753-755. Mostly a compilation from Roesel and Brahm. 1818. Hiner. Verz. Bekannt. Schmett, p. 375. 6514—No. 41—03——7 1819. 1825, 1826. 1829. 1831, 1833. 1833. 1834. 1837, 1838. 1840. 1840. 1841, 1844. 1845. 1846. 1849. 98 Turrs. Massachusetts Agricultural Repository and Journal, Vol. V, 364-367. Apparently the first account of the insect in American literature. Previous American writers had credited the plum eurculio with the cause of ‘‘wormy apples.’”’ Records some original breeding experiments by which he was led to conelude that the cause of most of the wormy apples in Massachusetts was a moth, and not a beetle or curculio. “ TuatcHerR. American Orchardist, second edition, p. 116. Records finding the worms on the trunks of trees, and therefore advises scraping off the rough bark and washing trunks with Forsyth’s composition. Apparently the first notice of the insect in horticultural books, and the first one to make any recommendations for controlling the insect. Kirsy and Spence. Introduction to Entomology, II, p. 123. TreitscHKr. Die Schmetterlinge von Europa, Vol. VIII, pp. 161-163. Many references to earlier literature. Descriptions. Brief compiled account of life history. Curtis. Brit. Entom., VIII, pl. 352. b] ‘*Rusticus.’? Entomological Magazine, Vol. I, pp. 144-146. A very good detailed account of the life habits of the insect. Eggs laid in the calyx cup. One brood. Apparently the first important article in the English literature. Bovcné. Garten-Insekten, pp. 113-114. Brief compiled descriptions ard account of habits. All that can be done to control it is to collect and feed out all wormy fruit as fast as it falls. SrepHens. Ill. Brit. Ent. Haust., IV, p. 119. Scumrppercer. In Kollar’s Naturg. der schiid. Insecten. (For English translation see Loudon and Westwood’s edition of Kollar, pp. 229-232, date 1840). Good general account. Two broods indicated. (He published an earlier and more complete account in his Natur. der Obst. schiid. Insecten, to which we haye not had access. ) Westwoop. Gardiner’s Magazine, Vol. XIV, pp. 234-239. Mostly a good compilation from the accounts by Reaumur and “‘ Rusticus.’’? One brood indicated. BurrELLE, New England Farmer, Vol. XVIII, no. 48, June 3, p. 398. ‘On the Curculio.”’ Records breeding the moth. One brood only. Apparently the first one to suggest the famous ‘‘ banding’? method. RatzEsurG. Die Forst-Insecten, Vol. I, pp. 234-236, pl. 14. fig. 7. Very good general account. Believes there is but one brood in North Germany, and doubts Schmidberger’s account of two broods in South Germany. Harris. Insects of Massachusetts, pp. 351-355. (In the editions of 1852 and 1862 no change occurs. ) Very good general account. Only one brood indicated. Gaytorp. Trans. N. Y. State Agr. Soc., p. 168. Brief account with Westwood’s figure. Recommends allowing swine to run in orchard. Insect then common in New England, but very rare in the Middle States. Liw. Schidliche Insecten, pp. 239-241. Largely a compilation from Roesel, with good discussion of remedies. Downrna. Fruits and Fruit-trees, p. 66. Brief account. Morris, Miss. (‘‘Old Lady.’’) American Agriculturist, Vol. V, February, pp. 65-66. Good account, with original observations, and illustrated by what is probably the first original figure of the insect to appear in American literature. Cote. American Fruit Book, p. 89. Brief account. Reports it numerous in New England and along the seaboard, and becoming more common in the Middle States. 1850. 1855. 1859. 1861. ° 1865. 1867. 1868. 1868. 1869. 1869. 1870. 1871. 1871. 1872. 1873. 1873. 1875. 1875. 1878. 1879. 99 Simpson. The Horticulturist, Vol. IV, p. 567. ’ Brief account of breeding experiments. Two or three broods indicated. Discovered that a cloth in the crotch enticed many worms, and after experiments with wax recom- mends that trees be sprayed with whitewash to fill blossom end of fruits and thus prevent egg laying at this point. Noérpuincer. Kleinen Feinde der Landwirthschaft, pp. 339-346. One of the best and most complete accounts which haye appeared in the German literature. Very good discussion of remedies. Believes it is single brooded in Germany. JAEGER. The Life of North American Insects, pp. 179-181. Brief, quaint account. GourEAv. Les insectes nuis. aux Arbres fruitiers, pp. 118-121. Very good general account. One brood in France: TrimsBie. Treatise on the Insect Enemies of Fruit and Fruit Trees, pp. 103- 139. Three full-page colored plates. One of the best accounts in the American literature. Detailed notes on birds as enemies of the insect; ‘‘hay bands’’ deyised and experiments recorded. Bred two broods at Newark, N. J. Bortspuvau. Essai sur L’Entomologie Horticole, pp. 560-563. Fairly good general account. One brood. Watsn and Rirey. American Entomologist, Vol. I, pp. 3-6. Evidence in favor of allowing hogs to run in orchards. WatsH. Report on Insects of [llinois, pp. 27-29. Arguments for two broods in Illinois. Ritey. First Missouri Rept. on Insects, pp. 62-67. Good general account. Two broods. WatsH and Ritey. American Entomologist, Vol. I, pp. 112-114. Very good general account, illustrated by Riley’s well-known figures. Two broods, Ritey. American Entomologist, Vol. II, pp. 321, 322. Records experimental proof of two broods in latitude of St. Louis, and discusses hay- bands vs. rags for trapping the worms. TAscHENBERG. Ent. fiir Giirtner und Gartenfreunde, pp. 310-313. Good general account. Admits but one generation in Germany. (The same account occurs in his Prak. Insektenkunde, III, pp. 228-231; date, 1880.) ZELLER. Stettiner Entomologische Zeitung, p. 55. Rivey. Fourth Missouri Report, pp. 22-30. Good discussion of bands, Wier’s trap, lights, jarring, and the enemies of the insect. Ritey. Fifth Missouri Report, pp. 46-52. Records careful experiments with different traps on trunk, and the discovery of two parasites. 4 LeBaron. Third Report on Insects of Illinois, pp. 167-185. One of the best accounts in the American literature; based largely upon original obser- vations. : SaunpDErs. Report Ontario Entomological Society for 1874, pp. 48-50. Good general account, largely compiled from LeBaron and Riley’s writings. Two broods in Canada. Coox, A. J. Report Michigan Pomological Society for 1874, pp. 152-160. One of the best accounts in American literature, largely based upon original observa- tions. Records seeing the eggs, but does not describe them. THomas. Seventh Report State Entomologist of Illinois, p. 260. Two generations indicated. Woopwarp. Rural New-Yorker, Feb. 8 (Proc. West. N. Y. Hort. Soc. for 1879, p. 20). First published account of successful use of poisons ( Parisgreen) against thecodling moth, 1880. 1881. 1881. 1883. 1883, 1883. 1883. 1883. 1883. 1883, 1883. 1883, 1884, 1884, 1885, 1885. 1886, 1886. 1886, 1886. 1887. 1887, 100 Cook. American Entomologist, Vol. III, p. 2638. Also published in 1881 in Proc. Am. As. Ad. Sci. for 1880, p. 669; and in Rept. Mich. Hort. Soe. for 1880, p. 136. Records the successful use of London purple to destroy the insect; first test of poisons made by entomologists. Scumipt-GbsBen. Die schiid. und niitzlichen Insecten, pp. 121-122. Brief general account. Cooks. Insects injurious to California Fruit and Fruit Trees, pp. 13-19. One of the best discussions of the habits and methods of fighting it in our literature. (Practically the same account was published by the author in 1879, and again in 1883 in his book on ‘‘ Injurious Insects,”’ pp. 102-108.) Three broods indicated. Saunpers. Insects Injurious to Fruits, pp. 127-133. Very good general discussion. Cuapix. Report Second Annual Conyention of California Fruit Growers, pp. 17-25. Detailed account of an extensive experiment with bands and gathering infested fruit; over 15,000 moths caught in a fruit room in one season. Watton, Miss. Report lowa Horticultural Society for 1882, pp. 199-203. Good general account, with some valuable breeding experiments. Codling moth in California in 1883. Ann. Rep. State Board Hort. Cal., p. 18. CuHaprix. Progress of the orchards of California during 1883. Ann. Rep. Cal. State Board of Hort., p. 12. Mannina, Jacop W. Repelling and destroying codling moth. Trans. Mass. Hort. Soc., p. 10 ff. Goprrey, A. N. The codling moth. Kansas Hort. Rept. for 1883. p. 91. Gitter, Ferrx. The greatest pest of California insect pests, or the codling moth. In First Ann. Rep. State Board Hort. Cal., p. 72. Dec. Snow, F. H. The codling moth or apple worm. In Quart. Rep. Kan. State Board Agr. Atkins. Report Maine Board of Agriculture for 1883, pp. 356-363. One of the most important contributions to the American literature; it is based entirely upon original observations. One full brood and a partial second one indicated. Lintner, J. A. Apple Worm. Country Gentleman for Oct. 30, vol. 49, p. 897. Letter from H. C.§., Crozet, Va., in reference to enemies of the worm. GirarD. Traité d’Entomologie, Vol. III, pp. 714-716. Good general account. One brood. Codlin moth (in Victoria, Australia). Report of the Secretary for Agricul- ture. Crawrorp. Report on Insect Pests in South Australia, pp. 32-39. Good general account. WHITEHEAD. Report on Insects, prepared for Agricultural Department of Great Britain, pp. 62-67. Good general account. Forses. Transactions Illinois Department of Agriculture for 1885, Appendix, pp. 26-45. Records one of the first and most carefully and scientifically conducted experiments with poison and lime against the insect. Eight applications made. Gorr. Fourth Report of New York Agricultural Experiment Station, 1885, pp. 246-248. Records one of the first carefully conducted experiments with Paris green. Wicxson. Bulletin 75, California Agricultural Experiment Station. Careful comparative experiments with bands and spraying. Kures. Sixth Annual Fruit Growers’ Convention (of California), p. 206. f E 3 : ’ 1887. 1887. 101 Cook, A. J. London purple against codling moth. Agricult. Sc., I, 9, Sept., 1887, p. 215. Forses. Bul. No. 1, Office of State Entomologist of Illinois, 26 pp. Results of scientific experiments with Paris green, London purple, and arsenic in 1886. Comparison of one, two, and three applications. Three broods indicated. 1887-88. Cuiaypo.r, E. W. Spraying for the codling moth. 21st Report Hort. Soc. 1888. 1888. 1888. 1888. 1889. 1889. 1889. 1889, 1890. 1890. 1890. 1890. 1890. 1891. 1891. 1891. 1891. 1891. 1891." Ohio, pp. 212-214. Howarp. Report U. 8. Department of Agriculture for 1887, pp. 88-115. The best and most exhaustive discussion of the insect at that time. From it have been compiled most subsequent discussions of habits and life history. Colored plate. Cook. Bul. 39, Michigan Experiment Station, pp. 1-4. Results from one, two, and three sprayings, and general conclusions from eight years’ experimenting with poisons. MecMitian. Bul. 2, Nebraska Experiment Station, pp. 68-77. Very good general discussion of habits and especially of remedies. Poreno—E and Maruarr. First Report Kansas Experiment Station, pp. 165-193. Valuable record of careful experiments with poisons and bands, including tables giving dates of blossoming of many varieties of apples. Pissor. Le Naturaliste, p. 60. Notes on metamorphosis, with detailed account of cocoon. Two broods indicated. GILLETTE. Codling-moth experiments. Bul. 7, lowa Agricultural Experi- ment Station, pp. 270. , Tryon. Report on Insects and Fungous Pests (Queensland, Australia), No. 1, pp. 48-49. Very good general account. GiuueTTr. Bui. 7, lowa Experiment Station, pp. 270-280. Very important and careful experiments with poisons and carbolic acid. Two broods, Kogsete. Bul. 22, Division of Entomology, U.S. Department of Agriculture, pp. 89-95. New and important observations upon the habits of the moth, the eggs, and the enemies of the different stages of the insect. Ouurr. Agricultural Gazette of New South Wales, Vol. I, pp. 3-10. Very good general account. OrmMEROD. Manual of Injurious Insects, pp. 286-290. Brief general account. Cook. Report Michigan Board of Agriculture for 1889, p. 320. Experiments to show that grass under sprayed trees may be safely fed to stock, Bos. Tierische Schiidlinge und Nuzlinge, pp. 526-527. Brief account. Frencu. Handbook of Destructive Insects of Victoria, part 1, pp. 45-55. Excellent general account; colored plate. Becxwitn. London purple v. Paris green for the codling moth. Bul. 12, Del. Agr. Expt. Sta., p. 16. Hupson, G. VY. A few words on the codlin moths (Carpocapsa pomonella L., and Cacoecia excessana Walk.). Proc. New Zealand Instit., vol. 23, pp. 56 ff. Cacoccia excessana, native to New Zealand, attacks applesin a similar way to Carpocapsa pomonella. GILLETTE, C. P. The codling moth. Bul. 15, Colorado Agr. Expt. Sta., April. Our, A.Stpnry. Codling moth. In Agric. Gazette, New South Wales, II, no. 7, July, pp. 385-386. Beckwith. Bul. 12, Delaware Experiment Station, pp. 16-23. Comparative test of Paris green and London purple, showing slight advantage for the former. 1891. 1891. 1892. 1892, 1892. 1892. 1892. 1892. 1893, 1893. 1893. 18938. 1893. 1894. 1894. 1894. 1894. 1894, 1894, 1894, 1894, 1894. 102 Wasusurn. Bul. 10, Oregon Experiment Station, pp. 1-16. Valuable record of careful experiments with poisons and bands. GILLETTE. Bul. 15, Colorado Experiment Station, pp. 4-18. One of the best and most accurate general discussions of habits and remedies. THompson. Handbook to the Insect Pests of Farm and Orchard (Tasmania), Part I, pp. 34-54. Excellent general account; two broods. LopemMan. Bul. 48, Cornell Experiment Station, pp. 268-274. Results of careful experiments with combination of poisons and Bordeaux mixture. Ouuirr. Entomological Bul. 1, Dept. Agr., New South Wales. Munson. Rept. Maine Experiment Station for 1891, pp. 99-109. Careful experiments with poisons and important deductions therefrom. KeELLtocc. Common Injurious Insects of Kansas, pp. 78-80. Good general account. Townsend, C. H. Tyxter. Codling moth. Bul. 5, New Mexico Station, March, 1892. WasHBURN. Bul. 25, Oregon Experiment Station, pp. 1-8. Record of original observations which form one of the most important and accurate contributions to the literature of the habits of this insect yet made. The egg figured for the first time. CoaquittettT. Bul. 30, Division of Entomology of U. S. Department of Agriculture, pp. 30-33. i Notes on life history, supposed enemies, and methods of combating the insect in California. Lintner. Ninth Report on Insects of New York, pp. 338-342. Detailed account of the work of the second brood of larve in New York; and a discussion of the prevalent ideas regarding the egg-laying habits of the insect. Ritey. Bul. 23, Maryland Experiment Station, pp. 71-77. Very good general account of habits, remedies, and especially of*its enemies. LopeMan. Bul. 60, Cornell Experiment Station, pp. 265, 273-275. Experiments to show that usually two applications of poisons are all that are necessary or profitable in New York. Smirx. Entomological News, Vol. V, pp. 284-286. Records breeding experiments which indicate but one brood of the insect at New Brunswick, N. J. Maruatr. Insect Life, Vol. VII, pp. 248-251. Evidence from various sources to show that inseet is usually double brooded. Sempers. Injurious Insects, pp. 57-59. Brief general account. ScHitiinc. Der Praktische Ratgeber, vol. 9, pp. 121-123; 133-135; 141-148. The best discussion of the insect from a practical and economical standpoint in the German literature. One brood. GoETHE, R. Experiments for catching larvee of Carpocapsa pomonella with paper rings. Bericht d. Kgl. Lehr. fir Obst. Wein, und Gartenbau, pp. 20-21. CockEreELL, T. D. A. The codling moth. New Mexico Entomologist, No. 1, Apr. 21, 1894. Garman, H. Spraying for codling moth. Bul. 53, Ky. Agr. Expt. Sta., December, 1894. Bruner. Insect enemies of the apple trees and its fruit. Nebraska State Hort. Soe., 1894, p. 215. WasHBURN. Bul. 31, Oregon Experiment Station. iy 1895. 1895. 1895. 1895. 1895. 1895. 1895. 1895. 1896. 1896. 1896, 1896. 1896. 1897. 1897. 1897. 1897. 1897. 1897. 1897. 103 Maruatr. Proceedings Entomological Society of Washington, Vol. III, pp. 228-229. Suggests that Merriam’s life-zones may explain and determine the variation in and number of broods of the insect. Weep. Insects and insecticides, Second Edition, pp. 88-89. - Brief general account. ; GorTHE. Bericht d. Kgl. Lehr. fiir Obst. Wein, und Gartenbau, pp. 22-25. Records original observations (from breeding-cage experiment) on the egg and on the habits of the young lary, with illustrations and descriptions. First definite account of these phases of the insect to appear in any foreign literature, . ADKIN, Ropert. The Entomologist, vol. 29, p. 2. Nut-feeding habits. THEOBALD, F. VY. The Entomologist, vol. 29, p. 28. Nut-feeding habits. Apxin. South London Entomological Society. The Entomologist, vol. 28, p. 340. Nut-feeding habits. Westwoop. South London Entomological Society. The Entomologist, vol. 28, p. 345. GARMAN, H. Experiments for checking apple rot and codling moth. Bull. 59, Ky. Agr. Expt. Sta., December, 1895. SmitH. Economic Entomology, pp. 322-323. Good general account. Loprman. The Spraying of Plants, pp. 242-255. Good general account. SLINGERLAND. Michigan Fruit Grower, Vol. V, p. 8 Paper read before Mich. State Hort. Soe. Detailed account of original observations on oviposition and the habits of the young larve, resulting in the discovery of some new and important economic facts. (The paper also appears in Rept. Mich. Hort. Soe. for 1896, and that portion of it relating to ie codling moth in the Rural New Yorker for Jan. 30, 1897, p. 67; and in the Proc. West. N. Y. Hort. Soc. for 1897, pp. 28-30.) Bos. Tijdschrift over Plantenziekten, Vol. XII, pp. 92-74. Very good account compiled from the writings of Schilling and Goethe. Lounssury. Report Government Entomologist for Cape of Good Hope, for 1895, pp. 33-36. _ Brief account. WALSINGHAM. Proceedings Zoological Society, London, p. 130. Concludes that Cydia is the proper generic name. a SmirH. Garden and Forest, Vol. X, p. 334. Notes peculiar differences in habits of the insect in New Jersey, and especially at New Brunswick, N. J. ScHoyreNn. Notes on insects of Norway and Sweden. Bul. 9, n.s., Div. Ent., U.S. Dept. or Agr., p. 80. SLINGERLAND, M. V. New facts about the codling moth. Garden and Forest, X, 468, Feb. 10, pp. 58-59. Carp, F. W. Notes on the codling moth. Garden and Forest, Aug. 4, Vol. X, no. 493. Carp. Garden and Forest, Vol. X, pp. 302-303. Detailed account of original observations on egg laying and the habits of the young lar- ye in Nebraska. Eggs laid mostly on the leaves, and two broods, at least, indicated. Det GueErcio. Bulletino della Soc. Ent. Italiana, pp. 12-17. Very good general account. 1897. 1898. 1898. 1898. 1899. 1899. 1899. 1900. 1900. 1901. 1901, 1901. 1902. 1902. 1902. 1902. 1902. 1902. 1902. 1902. 1903. 1903. 104 Carp. Bul. 51. Nebraska Experiment Station, 39 pages. Interesting original observations on the eggs and habits of the young larvee, with record of experiments against all stages of the insect. SLINGERLAND. The codling moth. Bul. 142, Cornell Uniy. Agr. Expt. Sta., 62 pp. 20 figs. The best account of this insect published. Gives summary of knowledge to date, including the greater part of the annotations of the above bibliography; illustrated with photographs. $ Merriam. Life Zones in the U.S. Bul. 10, Div. of Biological Survey, U. 8. Dept. of Agr. Describes the different zones. LuaeGer. Fourth Annual Report Minnesota Experiment Station, pp. 242-248. Harvey & Munson. Apple insects of Maine. Bul. 56, Maine Agr. Expt. Sta. p. 133. Hepricx, W. P. Results of spraying experiments and a wasp which destroys larvee. Bul. 64, Utah Expt. Sta. WoopwortH & Cotpy. Paris green for the codling moth. Bul. 126, Cal. Expt. Sta. GILLETTE. Entomological notes from Colorado, Bul. 26, Div. Ent., U. 8. Dept. of Agr., p. 76. AupricH. The codling moth. Bul. 21, Idaho Agr. Expt. Sta. Simpson. Report upon an inyestigation of the codling moth in Idaho in 1900. Bul. 30, n. s., Div. Ent., U. S. Dept. of Agr., p. 57. Maruarr. Important insecticides, directions for preparation and use. Farm- ers’ Bul. 127, U. 8. Dept. of Agr. Srupson. Gem State Rural, No. 14. Published conclusion that there are two generations at Boise, Idaho. GittETtrE Number of broods of the codling moth, as indicated by published data. Ent. News, XIII, p. 193. One of the most complete studies of the life history of any insect. Finds two genera- tions in Colorado. GitteTtr. Life history studies on the codling moth. Bul. 31, n. s., Div. Ent., U. S. Dept. of Agr. Srreson. Report on codling moth. Investigations in the Northwest during 1901. Bul. 35, n.s., Div. Ent., U.S. Dept. of Agr. 29 pp. 5 plates. GarcIA. Spraying orchards for the codling moth. Bul. 47, New Mexico Agr. Expt. Sta. Prrer. Orchard enemies in the Pacific northwest. Farmers’ Bul. 153, U.S. Dept. of Agr. CorpLey. The codling moth and late spraying in Oregon. Bul. 69, Oregon Agr. Expt. Sta. Finds two generations and notes important variations in life history. Sanperson. Report of the. Entomologist, 13th annual report of Delaware Agr. Expt. Sta., p. 172. SLINGERLAND. Trap lanterns or moth catchers. Bul. 202, Cornell Univ. Agr. Expt. Sta. Results of extended experiments with trap lanterns. CooLtey. The codling moth. Bul. 42, Montana Agr. Expt. Sta. Simpson. Observations upon the life history of the codling moth. Bul. 40, n. s., Div. Ent., U. S. Dept. of Agr., p. 63. 1903. 1903. 1903. 1903. 1903. 1903. 1903. 1903. 19038. 105 WasHBurN. A criticism upon certain codling moth observations. Ibid., p. 65. AupricH. The codling moth. Bul. 36, Idaho Agr. Expt. Sta. 16 pp. Reports a partial third generation. Buscx. Dimorphism in the codling moth. Proce. Ent. Soc. Wash., Vol. V, No. 3, p. 235. Describes new yariety. SLINGERLAND. American Fruit Culturist. The insects destructive to fruit. pr Lee. A short general account. Frernatp, C..H. Bul. 32, U. S. Nat. Mus., p. 471. List of N. A. Lepidoptera, H. G. Dyar. Wesster. The use of arsenate of lead as against the codling moth. Proe. 24th meeting Soc. for Promotion Agr., pp. 65-71. SanpErson. The codling moth. Bul. 59, Del. Agr. Expt. Sta. Simpson. The control of the codling moth. Farmers’ Bul. 171, U. 8. Dept. of Agr. Busck. Journal New York Entomological Society, Vol. XJ, June. Restores generic name Carpocapsa. 6514—No. 41—03 8 . O i ; nee *; iti aps aoe vy _ WITH we ‘PREPARED UNDER THE DIRECTION OF THR’ ENTOMOLOGIST, ) / Da , | + \ 1% 0° RY M. WEBSTER, M.S., ee Special Field Agbnt. ‘ - Roseccss ¥ ~~ WASHINGTON : ) GOVERNMENT PRINTING OFFICE, — 1903. f : “/) ) hake . tes. DEPARTMENT OF AGRICULTURE, DIVISION OF ENTOMOLOGY—BULLETIN No. 42. L. O. HOWARD, CHIEF OF DIVISION. SOME INSECTS ATTACKING THE STEMS OF GROWING WHEAT, RYE, BARLEY, AND OATS, WITH - METHODS OF PREVENTION AND SUPPRESSION. PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST, BY BoM VY eS ERY NES. Special Field Agent. SS See 1 WASHINGTON : GOVERNMENT PRINTING OFFICE. TOO. LETTER OF TRANSMITTAL. UnirEp States DEPARTMENT OF AGRICULTURE, Division OF ENTOMOLOGY, Washington, D. C., September 25, 1903. Str: I have the honor to transmit herewith the manuscript of a paper entitled ‘‘Some insects attacking the stems of growing wheat, rye, barley, and oats,” prepared under my direction by Prof. Francis M. Webster, temporary field agent of the Division of Entomology, and now stationed at Urbana, Ill. Professor Webster has acted as field agent of this Division, having received temporary appointment since 1884, with headquarters at the experiment stations of Indiana, Ohio, and Illinois, and is ably qualified for the prosecution of the present work through years of study in the States mentioned of the insects which will be treated. As remarked in the introduction, this paper deals with the injuries committed to small grains by different forms of minute flies, eight species in all, which are generally confused by the average farmer with the Hessian fly. The differences between these various species and their method of attack in comparison with that of the Hessian fly are duly pointed out, and many valuable sug- gestions based upon an intimate knowledge of the habits of these insects are made for the mitigation of their ravages. In most instances losses by these insects could be prevented by the simplest of farming practices, as set forth in their proper place. I recommend the publi- cation of this report as Bulletin No. 42 of this Division. The fifteen text figures are necessary for the purposes of illustration, those illus- trating plants having been kindly loaned by the office of Agrostologist. Respectfully, L. O. Howarp, Hon. JAMES WILSON, Entomologist and Chief. Secretary of Agriculture. —-- — Pec NENT St: Tlmameolneiinn ~ siebles eater bese sohoee Bee ae oak te ee eae eben ee esr Pei GneMINe 4752 aes kee e ke tas he es oe eee oe eee toe Se anes Dealing with the destructive species outside of the grain fields-.------.-- The greater wheat straw-worm (Jsosoma grande Riley) .-.--.------------- Brewmousmecoranon ihenmsech face sto eae emcee sane ssa ea ie ae Diseevary.o tse subsmer forms s soos 25 Soh. e ae see bee eS Discovery of dimorphism and alternation of generations ...--.------ ulema mame, lacsomatruicr, INVANG 22/2 2S 2 0s) aoe os el PRI AR Ee het ert eis oe ee PRG oe Pe Rete Ses Oviposition of the spring form (minutum) -..-...------------------- Oviposition of the summer form (grande) .......------------------- Bircreinnginas 4 megaman torte ean Pe ee Ihe ot eA Sad athe Adults of summer form (Jsosoma grande Riley) ----------------- Larva, pupa, and egg of summer form -..-...---..-.--=---- Adults of spring form (Isosoma minutum) ..--.------------------ Larravand pupa ol spring fore oS 3: esos eee 2 Se Peeereai micrantha mee rewn eRe Sy dx ee Se te oe oes = Sa Preventive. anduremedialimecasuness 22452 22).-.2- eee al= oe IOUS HaS oynleo vol we AI a a i Ce egies Ae eee 8 emt The joint worm (Jsosoma tritict Fitch) ..----.-+-..=---.-+--5-22---+---5- Previous record of the insect: .-2-----2-2-.=-==-- Fs None ek ae ae it cee Oe rd tebe See eo eto 8 aes 2 OS ie ed SA Ae TDRSANSTGY Se hees RE 8 eee ee ee ee eh een oes tae Mpsemipienmiawsaeiae tes) Fo Rok oe ck cts eas en oe ote a See INGUDON RESO se ees we Ee ee noe SE See eters ae UNCC TTh es Tse oS SES Sm ee ere ee ee ee ee cease Nou ene mite sent eee Nee ee ay St ern a one yw eh het Bee roe sh Remedial and preventive measures ....-------------t------+--++--- Ditneultymmerecoenizing the species. 520. 2.2-5---2225 2.227 525c5 2 The barley straw-worm (Jsosoma hordei Harris)..----------------------- Previous TeCOLds OMmMedNSECt oss 222 Soe eae ee ee mae Sales = eee Hwremareiny sme See eee oS 2 ea eit apa dee= =e =e Bieciroi tine isutves om the plait 22-225 >S50 5 tees es eos s Pesieripiigtie $2 ae ot geen ss eee see 21a 55 isaac PATGHITIG RE erat ene eat eg ae i oe Sed SESS re Arle en ee oa eet ya ee te? eos yt SORE Nain! GUVeTINEs)|- oS 84 3 oe sk ee eee essa or aaeee ee Seer Ses noe TANTET PELE Sin 0 2 ee a oe ee ee ee mtr ees The captive Isosoma (Isosoma captivum How. ).------------------------- The genus Isosoma—Continued. Webster’s Isosoma (Isosoma webstert How.) .-..----.----------------=-- Deseriptionvel adult females: 2 Sosa. eee 6 soot eee ee The hairy-faced Isosoma (Jsosoma hirtifrons How.) .-------------------- Description of adult female s.27 2 2 se oe ere te ee ee Tsasomuasecale Piteh =. . =”... 2o58. oe eens se oe re ee eee eee Description te 223555 ee ee ee ee Adult temale 5 2) See ee et ee Pa sp ee Adarltimale. S220 FF ee ee SAE aoe ee ee eee Bitch’s Isosoma,. (Tsosoma, fitchiWows) 2c 2] oes 5-2 eee WMeseripiton: Ss soso ae eee es eee ei ete en eee Adultiemale’:. sce Seer. See eek te Demet a a Se eee eee ea € Aduliimalet tt cease ee oe ee eee Ree er nee ae ithe two-wineed. grain and erase Mies: 242-3 ase eee a are Were probably originally grass feeders... 222 .. -22-2-22--2 24-55 s65- Marly reports ob InjUtes toe ral soo nie nose eee eerie The greater wheat stem-maggot (Meromyza americana Fitch) .---.-.------ Pasi istory Of tie Insect sero ose rene ee tae eae eee Stes Pits cIStORY 2 yes iael SO eas tee ra eget heme oer Pood ipnis are r eel Oe se ae oe le ees eee ene oe eee Ditieultiesan- studying babite 22.2: 3oo22 2222 eae se eee ee eee Se Remedial and préventive measures )s.. 2-2 5s2-— see = Se Sate eee Deseription 2.6 fcc. 220 -.f= Soe Dae ree eee ae eee aie ee Conclusion * 39 49 PiU SPR TON Ss: Fic. 1. Canadian rye grass (Hlymus canadensis) ...............----1------- 2 WVittininorye arass( Ey nus Vr gmuicus), 4-822... 222 aS oe ot 2 Bek, 3. Greater wheat straw-worm (Jsosoma grande Riley), spring generation, LONER OPCML UAC OT Se ae ee ea ee Rr ene Rote ope ue 4. Greater wheat straw-worm (Jsosoma grande Riley ), adult summer form - 5. Head of wheat partly destroyed by Isosoma minutum.........------- 6. Method of oviposition of female of summer form (J. grande); 6, point ii sirawewmnere eros placed foo 55-002 se ot gL ee 7. Pediculoides ventricosus Newp., a mite which destroys the larva. .----- So elsosome ite: Bitch. adult of toe joint worm) —.2 22 s2_) 222-3 eee o) Etiecton jomt worm imi wheatistrawe--22252.2-5.--23.-..-.5- Eee ae 10. Isosoma hordei Harr.; adult of the barley straw-worm --.-....--.---- ide isnsone, CopueMin Elbows = Adil saa 2 se sec ses nso nolo yee 8: Ga esee i sel soso weaustertLlows sacultiemales: s- 2.2. 222522 2 ye ee eee is isosome durtiyrons How.: adult female... .-2-\.2..<..----226 2400.2 4-5 14. Greater wheat stem-maggot.( Meromyza americana Fitch); stages and Puech On younes wheat plant 2562." 22 hlot. vss ogee. Se eee Oscinis soror Macq., stages; d, head of Oscinis carbonaria.......------ 22 44 52 SOME INSECTS ATTACKING THE STEMS OF GROWING WHEAT, RYE, BARLEY, AND OATS. INTRODUCTION. Throughout the United States, where the smaller cereal grains— wheat, rye, barley, and oats—are to any considerable extent cultivated, a multitude of injuries to growing wheat are charged by the average farmer to the Hessian fly; whereas, in many cases these ravages are really the work of insects whose habits differ greatly from those of that insect. Indeed, some of them are not flies at all, and even where the ravages are caused by flies, these are not necessarily the Hessian fly, and the same remedial and preventive measures that are applicable to this notorious wheat pest may not be at all effective against them. In fact, it is with the hope of enabling the farmer, as also the economic student, to distinguish between some of the chief insect enemies of cereal grains, and especially between many of them and the Hessian fly, that this publication has been prepared. In the following pages the author has restricted himself to the con- sideration of two groups of grain-affecting insects, the one composed of true flies, and the other not, though both during their developmental stages live and thrive within the stems of wheat, and to some extent within those of the growing grasses as well. Indeed, as a whole, they were doubtless primarily grass feeders, and their grain-attacking habits, being of more recent origin, brought about by the changed con- ditions of their natural food supply, consequent upon the influences of advancing civilization, may be looked upon as a modification of their original methods of living. While this variety of food plants, including the wild grasses, as well as the cultivated grains, probably has the effect of more generally diffusing some of these insects, thus rendering serious outbreaks of less frequent occurrence, the other phase of the problem is that though the farmer might exterminate them from his fields, they would still inhabit the grass lands and from there continually send a fresh supply of colonists into his fields to repopulate them. But, again, this has its redeeming features, as it enables the grain grower, in some cases, to’ meet his enemies in the grasses and there fight them to better advantage to himself than in his cultivated fields. The Hessian fly is 7 8 an exception, as it has yet to be found attacking the grasses in this country; yet several insects whose injuries in the wheat fields have been charged up to it by the farmer may be destroyed to a greater or less extent by closely pasturing the roadsides and fence corners in summer or burning them over in winter or early spring. The first group of these grain-attacking insects to which attention will be here given is composed of those that are not flies at all in the true sense of the term, but small ant-like creatures, really related to the ants which they so closely resemble. Their young live within the stems of the smaller cereal grains and grasses, and, though these rarely kill the wheat stems outright, they may either prevent the production of the kernels or cause these last to shrink and shrivel, thereby greatly reducing them both in weight and market value. These insects are called the grain and grass Isosomas, and their young are the wheat straw-worms and the joint-worms. What is still more surprising, they belong to a group of insects the majority of which are not vegetable feeders, but parasitic on other insects, and it was a long time before entomologists were willing to accept the fact that they were the real depredators and not parasites. This doubt as to the real food habits of these insects had not entirely disappeared up to 1884, when the author proved by successive rearings not only the vegetal habits of one of the species, but also the even more interesting fact of dimorphism and an alternation of generations, showing that what appeared to be two species was really two generations of one of them; but one of the generations, being wingless in the adult stage, renders it the more easily controlled by the farmer through a rotation of crop.¢ The second group of insects here considered is composed of true flies, and these also are both grain and grass feeders in the larval or maggot stage. All true flies have but two wings, and the maggots have no jaws, but the mouth parts consist of two minute hooks whereby they tear or shghtly wound the surface of the tender stems and suck the juices flowing therefrom. The Hessian fly is also a true fly, but its form partakes more of that of the mosquito, while these under con- sideration have very much the form of the common house fly, except that they are smaller, and they are frequently quite differently colored. The maggot of the Hessian fly is larger and more robust than are those of the Oscinids, though shorter and differing in color from those of Meromyza. Judging from my own experience and observation, these insects are much more injurious to the young grain plants. One brood of mag- gots of Meromyza work in the full-grown straw it is true, but, as a rule, the injury at that time is seldom very severe, while the larve of the Oscinids are rarely found in the full-grown straw, except in the @ Reports U.$. Comm. Agr., 1884, pp. 383-387; 1885, pp. 311-315; 1886, pp. 573-574. 9 extreme north, notably in Minnesota, and in Manitoba and the North- west Territories in Canada. The Isosomas do not attack the grain plants in the fall, and thus we have a natural division between the two, which is applied in the discussion of these insects in the following pages. The Oscinids are not destructive in this country alone, as allied species have long been a serious pest in England, France, Germany, and Sweden. The frit-fly (Oscinis frit Linn.), is some years especially destructive in Europe. The gout-fly (Chlorops teniopus Meigen) and the wheat bulb-fly (/Zylemyta coarctata Fallen) are both more or less injurious to small-grain crops in England. In the preparation of this bulletin the writer has been greatly aided by Dr. Howard and his corps of assistants, both in the Department of Agriculture and also in the United States National Museum, and by Dr. S. A. Forbes in kindly and promptly placing the notes and collections of the Illinois State Laboratory of Natural History at the author’s disposal. The writer is also indebted for specimens to Dr. James Fletcher, entomologist and botanist for the Dominion of Canada, and for similar favors received from Prof. F. L. Washburn, State ento- mologist of Minnesota. THE GENUS ISOSOMA. The grass and grain joint-worm flies belonging to this genus are widely distributed in America, some of the most important ranging from the Atlantic to the Pacific coasts and from Canada southward probably as far as the grains, wheat, rye, and barley are grown. The genus Isosoma is known to inhabit Europe, Africa, Madeira, St. Vincent, Australia, and Tasmania. In Europe it ranges over Russia, Switzerland, Germany, Austria, and Italy. When the insect faunas of Asia and Central and South America come to be better understood, we shall in all probability find that species occur in those countries also. These insects belong to the Chalcidide, a family of parasites whose normal food is other insects in one or more stages of their develop- ment. For a long time entomologists refused to believe that the species of Isosoma and their allies were exceptions to this supposed rule, and Harris firmly believed that /sosoma hordei was a parasite and not the true depredator in barley straw. Dr. Asa Fitch after- wards established the fact of phytophagice habits in /. horde7 as well as in several other species, but English and European entomologists were not wholly convinced, at least not all of them, up to as late as 1882. When the writer began the study of grain-infesting Isosoma in t884, comparatively little was known of the habits of some of our most common species, and the establishing of the fact of dimorphism 10 and alternation of generations by him in the case of /sosoma tritici Riley, as it was then known, and /. grande was without a parallel, in this genus, and so remains in this country. Among the ten or twelve American species that I have reared, none of the others, so far as I have heen able to determine, enter the pupal stage in the fall and winter in that condition,” and thus the greater wheat straw-worm (/so- soma grande) is one stage in advance of the others in spring, and the spring form, m7nuta, is developed at the time when other species are entering the pupal stage. This is also the only species that I have not succeeded in rearing from food plants other than wheat, with the possible exception of /sosoma websteri, which might have been reared from young cheat plants, though I hardly think this probable. The fact that I have only found this latter species in spring, and then only females, is indicative of a dimorphism and alternation of generations; but unless it be an undescribed species reared from stems of Zricuspis sesleroides, which is very late to mature, being even later than any other species known to me, I do not think such alternation can be connected with any other species that I have studied. On the other hand, and at the other extreme in the matter of food plants, the Elymus Isosoma (/. elymi French), has never been with certainty reared from wheat, though abundantly from the stems of cheat grow- ing among wheat and from Elymus growing along the margins of wheat fields. I also find, much to my surprise, that I have reared Fitch’s /sosoma tritici aside from its known food plant, wheat, only from Llymus vir- ginicus. Even where this latter grass and the closely allied 4. cana- densis have grown side by side, the joint worm (Lsosoma tritici Fitch) has held strictly to the former. The white-spotted Isosoma (I. albomaculata Ashmead), perhaps the most closely allied to /. grande of any of the species known to me, and which we should suppose would more than any other incline to dimorphism and alternation of generations, seems, however, to show no such tendency, and, more- over, I have reared it from both cheat and A/ymus virginicus, the life cycle, so far as I have been able to follow it, being parallel with those of Lsosoma elymi, I. tritici, and I. hordei. 1 do not, of course, wish to obscure the possibility of an alternation of generations among these insects, with a different food plant for each generation. On the opposite page is given in tabulatedform the food plants of the spe- cies of Isosoma known to attack grains and grasses in North America. a@Should the observations of Dr. Andrew Nichols, given under Isosoma hordei, prove correct, this may in future prove erroneous as to J. grande, unless the latter also attacks barley.—F. M. W. — a Se | . | : | 3 | : | P =) | 5 | |B le | a | cE) 5 D cl | 1 o _| gia) | |8iels ladle] [8 @ |g Heh | - | (se al Sees rele! at HO | taal 5 D oF Pe) Dl ee aa = i sel Bis l(SlSlBlslSlBlelelselsisiglais a|/e8/Si/elolo|/h|@/ala}o} #& Wet on sale =e -—a | Ss oO 3 — u eS | & & = a w/a l/s a) elald|/o|/Aal|Ss)/a;a)a}alja)s ey | dS SS | pep pe bet a NF es st has fri lar oe | | via — | aS | | | WRORG Mees aso fee ince ecs easel 6 Sp scllSpes | sat] bes | Seceet be eel pei leer PA ay (ea i a ee ? IRV @ wens Ee Sone See eee cp aee Ieee S25: , the transverse line showing the track of the ovipositor. To place her egg, the female takes up her position . Just above the joint, with her head downward. She then straightens her legs, thus throwing her body away from the stem, at the same time bringing her feet almost directly beneath the body. She now brings the abdomen downward and forward between her legs, much 20 as a bee would do if alighting and instantly stinging an animal. The next move is to let the tip of the abdomen strike the stem and then go back to its proper position, but the tip of the ovipositor does not; on the contrary, it catches on the surface of the stem, directly beneath the body of the insect, and by putting its machinery in motion and drawing the stem toward her she slowly forces the ovipositor into the soft, juicy stem at the point where this is solid and not hollow, as is the case a short distance above and immediately below the joint. The tip of the ovipositor is‘composed of two flattened plates arranged side by side, the edges of which are sharp, and are propelled with a sort of rotary motion alternating with each other. In this way the ovipositor cuts and drills its way to the center of the stem, and an egg is forced down the interior and left in its proper place in the stem of the plant. The female recovers her ovipositor by again straightening her legs and pushing the plant from her. Only one egg is placed in the same location, though perhaps more than one is placed in the same straw by the same female, but if so they are placed above different joints in the straw. The larve must mature quickly, for, though pupation does not take place until about October, the stem ripens and becomes tough and woody, wholly unfit for the food of the larve, within less than a month. It would seem that the mother insect is aware of this, as she invariably selects es RECN Ces Pampa the greenest and rankest growing plants Riley): a, female inserting her eggs; in the more open spots, where the straw pean ee anes matures the slowest and remains green and juicy the longest. Briefly, then, the insect passes the winter in the stubble—with the exception of the few that have been removed with the straw—in the pupal stage. In late March or during April the spring form (minutum), small, jet-black, ant-like, and with rare exceptions wing- less females, eat their way out of their winter home and seek the young growing wheat plants. They deposit their eggs singly, placing them in the embryo head. These hatch within a few days and the larve mature and transform to the form grande, large, robust, also jet-black, with fully developed wings, in late May and the first two- thirds of June. These last are also females, and without pairing they begin to deposit their eggs in the now nearly fully developed straws. The eggs are placed just above the uppermost joint accessible to the female, usually the second or third below the head. But a single egg is deposited in a place, the object of the mother insect seeming to be to get it in the center of the stem in the more or less solid portion tinea ea ie enamine elie 4 21 just above the joint. The eggs, as with those of the spring brood, hatch in a short time, and the larve reach maturity by the time the straw has become too tough and dry to afford further nutriment. The larva at this time usually gnaws its way down into, or at least partly into, the joint, and without forming cell or cocoon, about October passes into the pupal stage. DESCRIPTION. ADULTS OF SUMMER FORM. (Isosoma grande Riley. ) Length of body, 4.2 mm.; expanse, 7.6 mm. Antenne rather more slender and less clavate than in the spring form and but half the length of the thorax. Thorax with the mesonotum slightly more rugulose; wings larger and less hyaline than in the winged specimens of the spring form, with the veins extending to the outer third, the submarginal nearly four times as long as the marginal; legs with the femora less swollen. Abdomen not so long as the thorax, stouter than in the spring form, ovate-acuminate, approaching typical Eurytoma. Less hairy than in the spring form, especially about the legs, the hairs about the abdomen being less numerous, less regular, and shorter. Coloration similar to that of the spring form, but brighter and more highly contrasting, the promotal spot larger and brighter yellow, the pedicel of the antennz yellow, and the femora with a definitely limited suboval yellowish spot below, near the tip, extending two-fifths the length of the femur on front pair, smaller on middle pair, and still shorter and less definite on posterior pair. Larva greenish yellow in color. Average length, 6 mm.; otherwise of same pro- portions and structure as in spring form.@ Pupa, average length, 5 mm. Except in larger size and ample wingpads undis- tinguishable from that of the spring form, minutum. Egg of the ordinary ovoid form with pedicel about twice as long as the bulbous part. The apical end is furnished with a distinct hook, perhaps for the purpose of holding the egg in place while the ovipositor is being withdrawn from the plant. ADULTS OF SPRING FORM. (Isosoma minutum. ) Length of body, 2.8 mm.; expanse of wings, 4 mm.; greatest width of front wing, 0.7 mm.; antennz, subclavate, three-fourths the length of thorax; whole body (with exception of metanotum, which is finely punctulate) highly ‘polished and sparsely covered with long hairs toward the end of abdomen; abdomen longer than thorax and stouter. Color, pitchy black; scape of antennee, occasionally a small patch on the cheek, mesoscutum, femoro-tibial articulations, coxze above and tarsi (except last joint) tawny; pronotal spot large, oval, and pale yellowish in color; wing veins dusky yellow and extending to beyond middle of wing; submarginal three times as long as marginal; postmarginal very slightly shorter than marginal, and stigmal also shorter than marginal. (See Riley, Am. Nat., 1882, p. 247.) Larva, length, 4.5 mm.; of the shape indicated in fig. 3; color pale yellow; mouth ‘parts brownish. Antenne appearing as short two-jointed tubercles. Mandibles with two teeth. Venter furnished with a double longitudinal row of stout bristles, a pair to each joint. Each joint bears also, laterally, a short bristle. Stigma pale, circular; ten pairs, one on each of joints 2 (mesothoracic) to 11. ‘Pupa, jet black without other coloring; smaller than that of summer form. That is to say, the pup wintering over in the straw and from which the spring form develops is thus to be described; that following the laryze developing in spring is understood to belong to the summer form. @Riley, Ann. Rept. U. S. Dept. Agr., 1884, p. 58. 22 NATURAL ENEMIES. Probably the most efficient enemy of this species is a small, slender, four-winged fly, of somewhat brilliant metallic-colored body and yel- low legs. This has a very slight resemblance to an Isosoma, and, indeed, was described .as /sosoma allynii, now known as LHupelmus allynii French. A somewhat similar insect with metallic body and yellowabdomen, Stictonotus 7sosomatis Riley, is very efficient in destroy- ing the larve in the straw. Homoporus (Semiotellus) chalcidephaqus Walsh and beyond a doubt other chalcids are also instrumental in hold- ing it in check. These parasites are all the more efficient as they are double-brooded also, developing in late summer and at once ovipositing in other larve. There is also an egg parasite that I have reared in connection with Isosoma, but not with certainty from this species. This is Oligos/ta americana Ashmead MS. As inall cases where I have obtained this there were species involved other than the one under con- sideration, it is obviously impossible to say that it destroys the eggs of this species, but with such regu- Z larity does it occur in connection with Isosoma in py ee general that no doubt it preys upon this one with the ventricosus Newp.,2 others. When the wheat is harvested the straw is mite which destroys 5 5 : the larva—much frequently, and, in fact, almost invariably, cut off ee ae between joints, thus leaving the larve, if there are such in the straws at that point, exposed to attack from predaceous insects. The larve of a small, slender, black and yellow carabid beetle (ZLeptotrachelus dorsalis Fab.) crawls up, descends into the stubble and devours the Isosoma larve, but unfor- tunately its taste seems to be too obtuse to allow it to confine itself strictly to Isosoma, and as a consequence it devours parasites as well as host. The mite Pediculoides (Heteropus) ventricosus (fig. T) is also an enemy, gaining access to the larve precisely as with the beetle larve previously mentioned. PREVENTIVE AND REMEDIAL MEASURES. The fact of the spring brood being almost entirely wingless and therefore unable to fly from field to field places it almost totally at the mercy of the farmer, as he has but to change his crop from one field to another to rid himself of its presence. It is true the summer form can fly about from field to field at will, and it does so, but if the spring brood of adults are left helpless in a field with no wheat plants in which to place their eggs, it will be seen at once that there can be no sum- mer brood emanating from this source. Rotation of crop will asa consequence be suflicient to prevent an overabundance of this species. But there are conditions under which this is not practicable, as in some Sa tytn ss 238 sections and with some farms the soil is but little fitted for other crops, and where wheat follows wheat year after year for an indefinite period. Under such conditions, burning the stubble before preparing the ground for the new crop in fall will prove effective. If this burning is delayed until September, many of the parasites will have developed and escaped. The burning can be best carried out by cutting the grain as high as possible, leaving the stubble long. A few days before burning a mower should be run over the field, cutting off all grass and weeds, which, when dried, will! add to the fuel supplied by the stubble. Taking advantage of a favorable wind, the farmer can burn oyer his field cleanly, thereby not only ridding it of the presence of this pest, but also the Hessian fly, besides burning up much of the seed of foul weeds and grasses. DISTRIBUTION. This species seems to occur throughout the middle belt of country from the Atlantic to the Pacific, wherever wheat is grown as a staple crop. Whether it is single-brooded in the North and is, therefore, in such countries capable of sustaining itself in spring wheat, is not yet known. Having no other known food plant than wheat, it will neces- sarily follow that its range will be restricted to areas of wheat culti- vation, and being double brooded, requires fall wheat in which to develop. The fact of its having been so long confused with what now seems the true joint-worm fly (/sosoma tritict Fitch) renders its actual distribution, as well as the extent of its ravages in the past, somewhat obscure. I found the summer form (grande) in considerable numbers in spring wheat at Lafayette, Ind., June 19, 1895, and it is likely that it can breed therein, though fall wheat is necessary for form mnutum. THE JOINT-WORM. (Isosoma tritici Fitch. Figs. 8 and 9.) I have previously referred to the confusion of /sosoma trétici Fitch with /. horde Harris, and which was so persistently insisted upon by Walsh and Riley. It was not until 1896 that Dr. Howard succeeded in establishing the fact that this is a valid species, and now we are con- fronted with a long series of complications that can only be safely corrected by carefully rearing both species and studying them anew. Failing entirely in securing sufficient material from wheat in carrying out the investigations upon which this bulletin is based, I feel now very much like letting the insect alone until an opportunity is offered to untangle the knotted skein. Doctor Fitch stated distinctly that the term ‘‘joint-worm” was to be applied to the insect attacking wheat, and it was because of the mistake of considering it the same insect as that described by Harris that the name ‘‘joint-worm” came to be applied to /. hordet at all; a mistake that belongs neither to Harris nor Fitch, but one that has misled nearly everybody. 24 : PREVIOUS RECORD OF THE INSECT. About the year 1848, in central Virginia, throughout the country adjacent to Charlottesville, Albemarle County, and Gordonsville, Orange County, the wheat began to suffer seriously from attack of what was at that time called the joint-worm. In 1851 the wheat in Albemarle County was, much of it, not worth the harvesting. In 1854 the ravages of the pest had become so serious that a ‘‘ joint-worm convention” was held in Warrenton to devise means for controlling it and preventing, if possible, its further ravages, as by this time it had become almost impossible to raise wheat at all in the infested terri- tory. The action of this convention was to recommend a better sys- tem of cultivation, the use of guano and other fertilizers to promote the rapid growth and early ripening of the grain, and the burning of the stubble after harvest. > Fic. 8.—Isosoma tritici Fitch: adult of the joint-worm, much enlarged (from Howard). Looking back to this period, our later-day entomologists can hardly understand how there should have been any difficulty in determining beyond a possible doubt the author of all of this destruction. Doctor Fitch, who, it seems, received some of the growing wheat plants infested with the larvee from that locality, always insisted that he found a cecidomyian larvee inhabiting cells like those occupied by the joint- worm and that these were the true depredator, and, though he continued to stoutly defend his determination, we have yet to discover a Cecido- myia either causing or inhabiting such a cell or gall in the wheat plant. From all that has been since learned relative to these insects it is clear that the ravages were those of this species, with, perhaps, individuals of the preceding species intermixed among them. As a matter of history it may be stated that Doctor Fitch was still unconvinced that the joint-worm, and not a dipterous insect, was responsible for the dam- ee es ee eae noe 25 age in Virginia as so late as 1859 he expressed astonishment that he was unable to rear any Hessian flies from the same straw from which he reared the joint-worm. Surely the unento- mological farmer might be pardoned for falling into the same error until, at least, he is placed in possession of some way of distinguishing them from each other. After finding out beyond question that this is a valid species, that it is the true joint-worm fly attacking wheat and not barley, while /sosoma hordec attacks barley and not wheat, notwith- standing the effect on the straw is much the same, and that though it resembles Lsosoma grande rather closely, it is quite different in habits and life his- tory, we are forced to conclude that we really know very little about it. I have reared it in limited numbers from wheat straw in Illinois, Indiana, and Ohio, though it would appear that about 1885 it became excessively abun- dant in some parts of Michigan, and, in fact, I am not sure but that I have myself found the larvee in some abun- dance, but supposed them to belong to the preceding species. The uncer- tainty in regard to the identity of these larvee was owing to the fact that at the time they were observed this was not considered a valid species, and I at that time considered them as belonging to lsosoma grande, but now doubt my former opinion from the fact that this species does not always form galls either in wheat or Elymus, that there were several larvee between the joints instead of one, and that they were located just under the inner walls of the straw, but not forming a cell, whereas those of the species last con- sidéred is found only in the center of the straw, in the more solid sub- stance, immediately above the joint Fic. 9.—Effect of joint-worm in wheat straw (drawn in Division of Entomology). 26 itself. In 1885 Professor Cook described Jsosoma nigrum, which he states was reared from larve forming creases and hardened deformities in the straw. Professor Cook’s specimens, sent to Washington, have been determined by Doctor Howard as /sosoma tritici Fitch.“ (See also Walsh, Trans. Ill. St. Agl. Soc., vol. 5, pp. 485-490, figs.) LIFE HISTORY. The larve pass the winter in the straw, if in wheat, and in the stems of Virginia rye grass (Zlymus virginicus) in the Kast, and £. glaucus and another grass, either Bromus ciliatus or a species of Agropyron, in California. In the Middle West the adults appear the latter part of May and early June. The egg does not differ materially from that of . grande, and it is probable that the method of oviposition is much the same as in that species, the female placing her eggs in the young growing wheat plant just above the uppermost joint to which she can secure access at the time. Ordinarily the upper joint is not yet uncovered, except in case of very early wheat, and in that which has made less advance even the second joint from the head is so covered with the sheaths that the insect is unable to determine its position, so that sometimes we find more larve between the second and third joints than we do farther up between the first and second, precisely as with I. grande. The larve reach their full growth by harvest, but do not pupate until the following spring. All adults are winged, and both sexes are represented. Outside the wheat field I have reared the insect only from Elymus virginicus, and I question its breeding in the stems of cheat (Bromus secalinus) for the reason that I have reared it from the rye grass and not from the cheat, though both were abundant in the same locality. Mr. Koebele, who reared it from “lymus glaucus in California, was uncertain whether he also reared it from Bromus ciliatus or Agropyron. Both the Bromus mentioned by Koebele and Agropyron repens occur in the East, and it is very probable that future studies of the species will show that there are other grasses besides rye grass that will require attention from the farmer who wishes to guard against its appearance in his fields by preventing its breeding permanently along roadsides and the borders of his fields. DISTRIBUTION. Doctor Fitch received this insect from Maryiand, Doctor Lintner and Professor Comstock reared it in New York, the United States Depart- ment of Agriculture has it from Virginia and North Carolina, Pro- fessor Cook reared it in Michigan, I have reared it in Ohio and Illinois “Grass and Joint-worm Flies and their Allies, Tech. Ser. 2, Div. Ent., U. S. Dept. Agr., p. 18. 27 and found it in Indiana, Doctor Fletcher has reared it in Ontario, Canada, and Mr. Koebele in California, and there is hardly a doubt that investigations will reveal its presence throughout the entire wheat- growing region of North America. Being fully winged and single brooded, as well as capable of breeding in abundance outside of the grain fields, there seems no good reason why it should not cover the whole country, attacking either spring or winter wheat. DESCRIPTION. “‘Female.—Length 4 mm.; expanse 7.6 mm. Head, pronotum, and mesonotum strongly rugulose but not umbilicate-punctate except toward tip of scutellum, where an occasional umbilicate puncture occurs; metanotum also strongly rugulose, with a faint trace anteriorly of a median longitudinal furrow; metanotal spiracles large and perfectly circular; pronotal spots moderately large and often faint, but plainly dis- cernible from above, sometimes, however, quite bright and distinct. Abdomen longer than thorax, nearly as long as head and thorax together; abdominal segments 4 and 5 together longer than 2, 3 only about half as long as 4, and 5 as long as two preceding united; first funicle joint one-half longer than second; club longer than three preceding funicle joints together. Body slightly but plainly pilose except at sides of metanotum, where the fimbria is very obvious. Legs black except at joints, which, with the tarsi, are yellow. Claw of stigmal club given off before the tip. Male.—Length, 2.9 mm.; expanse,6mm. Petiole shorter than hind cox, faintly punctate; flagellum of antennz uniformly pilose, joints well rounded above, not strongly pedicellate; joint 1 three times as long as wide and nearly three times as long as pedicel; none of the funicle joints constricted in the middle; joints 2 and 3 each nearly as long as 1; joints 4 and 5 each a little shorter; elub plainly divided by a distinct incision into two joints, but the terminal ovate joint is not pedicellate.’’ Howard, Tech. Ser. 2, Div. Ent., U. 8. Dep. Agr., pp. 17, 18. Originally described by Fitch, Jour. N. Y. State Agr. Soc., 1859, p. 115. Cited as /sosoma hordet by Walsh, Amer. Ent. and Bot., IT, p- 332. Described as Decatoma basilaris by Provancher, Faun. Ent. Can, IT, p: 569. NATURAL ENEMIES. “ ’ The natural enemies are, with few exceptions, probably the same as with the preceding species, to which this is more closely related than with the one that follows, at least so far as its life history is concerned. In my own rearings I have invariably bred this in connection with 7. grande if from wheat straw, or with /. elym7i if from grass, so that personally I am not able to say that certain parasites actually came from J. ¢rétic?, though there is no reason for doubting that such was the case. Certain parasites do most certainly confine themselves to particular species of Isosoma. Websterellus tritici Ashm. has only been reared from this species, as it is now known. An undescribed Isosoma occurs in considerable abundance in the stems of Zrécuspis seslerioides, and from this I have reared a parasite belonging to the genus Torymus, but strangely enough this parasite has only been 28 reared from this particular Isosoma, even where the grass infested by its particular host was growing in the midst of Elymus, literally alive with the larve of three other species of Isosoma. Thus, while some parasites attack all of the species, there are evidently others that restrict themselves to one. REMEDIAL AND PREVENTIVE MEASURES. Owing to its possessing wings whereby it is capable of flying readily from one field to another, or breeding in the stems of grasses in the — intervening territory, a rotation of crop will be less effective in the case of this species than with the preceding. For the same reason, | careful attention to roadsides, borders of fields, and ditches becomes all | the more imperative. The burning over of the stubble fields before preparing the ground for wheat again in the fall, or the same treatment . of the uncultivated areas above mentioned at any time during winter or early spring will effectually exterminate these insects where these measures are carried out. In the Middle West wheat seldom follows | wheat on the same ground for a series of years, the grain being rotated with red clover, which prevents the burning over of the stubble fields | in the fall, but does not in any way affect the treatment of grass lands, : and if the crop is rotated annually and the borders and waste places attended to there is little likelihood of the farmer suffering greatly from the depredations of this insect. I have invariably found the. most serious injuries to occur on thin or poorly fertilized soils or where the land had not been thoroughly prepared before seeding. Probably whatever tends to produce a healthy, vigorous growth of the wheat plant will tend to discourage oviposition by the insect. It is not known that the insect prefers one variety of wheat to another, but the variety with the stoutest straw will probably suffer least from attack. DIFFICULTY IN RECOGNIZING THE SPECIES. Ihave made no attempt to describe the larva and pupa in their proper place, because I do not believe they can be separated by any descrip- tion from those of the preceding species if in wheat, or those of /sosoma elymi French if in grass. Notwithstanding this the farmer can readily separate them at the proper season of the year, even if both are present in his cultivated fields. After October this species will be in the form of a yellowish white larva in the stubble, while the preceding species will be in the form of a black pupa, both perhaps in the center of the stubble. In spring the larve of this species will change to a jet black pupa, while those of /. grande will have developed and escaped. So, then, pup found in the fall will probably belong to the preceding species; those found in spring, if in wheat, to this, and larve found after October, if in wheat stubble, also to this species. However, ae aati 29 too much reliance must not be placed on these distinctions, as there are other supposed species of these insects attacking wheat of whose larve and pupz we know nothing, but with our present knowledge the facts just given are the best that can now be offered the farmer in order to enable him to separate the different main enemies of his grain and receive whatever practical benefit is possible from what information is now available, leaving future studies to throw more light upon his problems. The adults can be easily separated from those of the pre- ceding species by their smaller size, and from the next by their smaller size and the color of the legs, which in 7. horde? are honey yellow. The larvee are also smaller than those of the following species and may or may not cause galls and deformities in the straw. The adults of the summer form of the preceding and those of the following species are abroad at the same time as are those of this species during the last days of May and early June. While fig. 9 illustrates the effect of the larve on a wheat plant, there are so many variations from this that it is at present impossible to separate these two gall-forming species by their effect on the straw. THE BARLEY STRAW-WORM. (Isosoma hordei Harris. Fig. 10.) Up to 1896 this species was confused with the preceding and the term ‘‘joint-worm” applied thereto. The fact is, Harris seems not to have given this name to his species at all, but on the other hand Doc- tor Fitch applied it to his 7. trdtéez, and it was owing to the confusion of these two insects that the name became misapplied, and I have here given Harris’s species the name ‘‘ barley straw-worm,” in accordance with the name horde/. PREVIOUS RECORDS OF THE INSECT. Of all of our described species of Isosoma this was the ‘earliest known and was for many years supposed to be the only species infest- ing cultivated grains or, in fact, inhabiting this country, as it was con- sidered a parasite on the real depredator, presumed to be some kind of a two-winged fly, and was actually described by Dr. W. T. Harris in 1830 as a parasite, under the name Jehnewnon horde?.“ Doctor Harris certainly seems to have been aware of the fact that as early as 1821 Mr. James Worth, of Sharon, Bucks County, Pa., found larve clearly belonging to some species of Isosoma affecting the culms of wheat ‘‘near the root, where they caused enlargements of the stem;”? and in 1823, Mr. Joseph E. Muse, of Cambridge. (Eastern Shore), Md., reared an insect, also from wheat, which ke termed a “a New England Farmer, July 23, 1830; Ins. Mass., 1841, pp. 434-437, b American Farmer, vol. 4, p. 394. 30 ‘**Tenthredo,” whose larvee, as he stated, ‘‘ burrow within the stems and feed upon them.”” Doctor Harris, in the edition of 1841 of his Insects of Massachusetts, page 434, refers to the statement of Dr. Andrew Nichols, of Danvers, who stated that worms found in his barley straw were about one-tenth of an inch in length and of a yel- low or straw color, and that in the month of November they appeared to have passed into the chrysalis state, but living through winter unchanged in the straw. The insects referred to by Mr. Worth, of Pennsylvania, and Mr. Muse, of Maryland, might quite probably have been /sosoma tritict Fitch, but if the one referred to by Doctor Nichols was an Isosoma at all it was certainly / grande, as that is the only species attacking grain that is known to pupate in the fall. Thus it will be seen that it is not easy to determine just what Harris might have included as belonging to his /. horde?, though he nowhere states that it was ever obtained from any other than barley straw; hence the name, horde, applied to it. It is interesting to know that specimens labeled in his handwriting ‘‘ Para- sitic in barley, June 15, 1830,” are still in the museum of the Boston Society of Natural His- tory, so that there can f \, be no mistake in the f } identity of the insect Fic. 10.—Jsosoma hordei Harris: adult of the barley straw-worm deseribed. Even in the (from Howard). edition of his Insects of Massachusetts, of 1841, Harris makes no mention of his species having been found affecting wheat. In the edition of 1852 he relates that about eight years before children sleeping on straw beds in Cam- bridge, Mass., had been bitten by these insects and the annoyance had been so great that the beds, both straw and ticks, had been burned. Now people do not use barley straw for such domestic purposes, nor in fact do they use wheat straw as a rule, but oat straw. As Doctor Harris does not enlighten us as to what kind of straw it was from which the insects annoying the children came, we stiil have no direct proof that this species was ever known in connection with wheat straw. About 1852 there appeared a similar trouble in the barley in cen- tral New York, and though Doctor Fitch described it as a distinct. species under the name Hurytoma fulvipes,? we now know that it was @ Loe. cit., vol. 5, p. 1138. >Jour. N. Y. Agricultural Soc., Vol. IX, p. 115. 31 tsosoma hordei. This last outbreak in central New York appears to have been rather widespread and disastrous, for in 1858 Hon. George Geddes, president of the State Agricultural Society, stated that while formerly a yield of 40 bushels of barley to the acre was expected, they could not at that time rely upon more than 20, and unless relief came barley growing, on account of the attack of this pest, would have to be abandoned. “ There was a local outbreak of this species in Ontario, Canada, in 1867-68, and observed at Wakeman, Chagrin Falls, and Barry, Ohio; Indiantown, Cuckoo, and Paynes, Va.; Albany, N. Y.; Canada West (William Couper); Ottawa, Canada; and Urbana, Carbondale, and Marshall, Ill. So far it has not been reported from the Pacific coast States. Doctor Fitch confined this species to the insect reared by Harris in Massachusetts, and the one working the injuries in central New York as J/sosoma fulvipes, both of which are now known to belong to /sosoma horde. LIFE HISTORY The species is single brooded. The adults of both sexes, all fully winged, emerge from the straw and grass in late May and early June, ovipositing almost immediately. The effect of the larve on the grow- ing plants begins to show within a short time, and, though the larvee become full grown during June and early July, they remain in this condition within their cells until May of the following year. EFFECT OF THE LARVZ ON THE PLANT. The eggs may be deposited in the stem of barley or grass anywhere between the root and the head, even among the lower spikelets of the head. The effect of the larvee may be to cause hard, woody cells, whose outline is indicated only by slight discolorations, the outer sur- face of the stem being smooth and not in the least swollen, the cell being entirely within the walls of the stem, causing no distortion in the straw; or there may be anywhere from one to a dozen galls ina cluster, and these may be either clearly defined or so packed together and cramped as to lose all semblance to the typical galls and take on the appearance of diminutive growths, resembling the black knot of the cherry and plum. The straw or grass stem may be enlarged to two or three times its natural size, forming an elongated oval woody growth that pushes its way outward, bursting, as it were, the sheath at base, and showing between the edges. This growth is usually on one side of the stem, just above the joint, and is marked with inter- lacing creases and furrows indicating the outlines of each individual cell, and in many cases sending downward from the lower extremity small root-like appendages, the use or cause of which it is difficult @Trans. N. Y. Agl. Soc., 1859, p. 332, 32 to understand. All of these malformations as well as others may be found in the stems of /Hlymus canadensis in abundance, from which swarms of the adults will emerge in late May and early June. Owing to the woody nature of these abnormal growths, straw attacked by this species is more likely to be broken up into small bits, and these go in with the grain at thrashing, thereby increasing the dan- ger of transportation from one locality to another, but to offset that, as it were, there is likely to be a greater proportion of the insects left in the stubble than with the other species, as the affected straws are usually more stunted in growth and shorter. At present there is no other insect attacking wheat, rye, or barley that causes similar growths in the straw except /sosoma tritici Fitch, in wheat, and the farmer can hardly mistake the work of these two pests for those of any other in his fields. DESCRIPTION. ‘**Female.—Length, 3.6 mm.; expanse,6mm. Pronotum and mesonotum minutely but strongly rugulose, smoother than J. tritici; metanotum more coarsely rugulose, the larger elevations taking a longitudinal direction, no central furrow or carina; pronotal spot very small, not visible from above. Abdomen as long as head and thorax together; joints 4, 6, and 7 subequal in length, the fifth a little longer; joint 3 a little longer than 4, 2 hardly longer than 3 and 4 united; funicle joints 2 to 5 sub- moniliform, but still a little longer than broad. All legs (except coxee) and antennee honey-yellow, flagellum and femora a little darker; claw of stigmal club straight, given off well before tip of club; pilosity sparse. ‘‘Male.—The only males which I have seen are the two from the Harris collection, These are both in very bad condition; neither had an abdomen and one has no antenne. With the other, but three funicle joints remain on the left antenna (the others being broken off) and four on the right, but the latter are still inclosed in the pupal sheath. The three funicle joints remaining on the left antenna are not pedi- cellate, very slightly arched above, and furnished with close, moderately short hair not arranged in whorls; joint 1 longest, 2 and 3 successively decreasing. Joint 4 is still shorter, judging from the sheathed right antenna.’’ (Howard, Tech. Ser. 2, Div. Ent., U. 8. Dept. Agr., pp. 18, 19.) The foregoing description was drawn up from specimens in the Fitch collection, labeled, in Fitch’s handwriting, ‘‘Hurytoma fulvipes Fh.;” other specimens from the Harris collection, reared from barley, June 15, 1830; other specimens from ‘** Canada West,” and still others reared by myself from stems of Hlymus canadensis growing near Champaign, Ill. This is the /ehnewmon hordet described by Harris in the New England Farmer, the Awrytoma fulvipes described by Fitch in his seventh report, and the /sosoma hordei mentioned by Walsh in the American Entomologist (Vol. I, p. 330). The larva, except from its larger size and habit of living within a cell, is not distinguishable from that of the other species of grain- infesting Isosoma. It is little larger than that of 7 grande, found in May and early June, and it has the universal yellowish-white color. The same may be said of the pupa. 33 NATURAL ENEMIES. The larvee appear to suffer more from the inroads of natural enemies than do those of other species of these insects, perhaps because of their inhabiting the walls instead of the center of the straws, thereby rendering them more accessible. It may be that this is the older form, and a greater number of the parasitic species have become adapted to it as a host insect. There is little doubt that Ol/gostta americana Ashm. and Polyneura citripes Ashm. both attack and destroy the egos, as I have reared them in numbers from stems of Elymus inhab- ited by the larvee, and also the stems of other grasses inhabited by other Isosoma larve. Hupelmus allynii French, easily known by its slender body, metallic color, with yellow legs, is associated with this as it is with nearly all other species of these insects that inhabit the stems of grain and grass. J/erisus ¢sosomatis Riley, conspicuous for its yellow body, is almost as abundant as the preceding, and, as the name implies, is parasitic on other species also. /Zomoporus chalei- dephagus Walsh is also a parasite, but I have reared it in lesser num- bers than the other two, in Illinois, Indiana, and Ohio. Almost the first parasitic species that I reared in connection with the present studies of /sosoma hordet was a second new genus and species, Para- pteromalus isosomatis Ashmead MS. I have myself witnessed the oviposition of all of these parasitic species, and their life history is probably practically the same. The adults emerge in spring a little later than those of the Isosoma, but there is a second generation of adults in summer, and it is these that I have observed placing their egos in the cells of 7. horde?, thus doubling their effectiveness in hold- ing it in restraint and preventing more frequent and greater devasta- tions in the grain fields of the farmer. While carrying on the present investigation I have reared an undetermined Eurytoma, a parasite on Isosoma, but as I reared four species of the latter from the same lot of stems, it is impossible to say to what extent it preys upon the one now under consideration, nor do I know anything in connection with its habits, except that it makes its appearance in spring, simultaneously with other parasites. PREVENTIVE MEASURES. The preventive measures might well be summed up under the caption of good farming, for there is not one practical measure but will pay for its carrying out, aside: from its entomological influ- ences. As the adults are fully winged and can fly freely from one field to another, less must be expected from a rotation of crop, but even under these conditions, a certain amount of benefit will result from a careful system of crop rotation. Wheat, rye, or barley should never be grown on the same land for more than two years in succes- sion without carefully burning over the stubble before preparing the 1327—No. 42—03-——3 34 ground for another seeding. To these must be added the mowing off of roadsides and along fences and margins of fields during late June or early July, or the burning over of these during winter or early spring, thus destroying the hibernating larve. The rye grass along the margins of fields and ditches should receive special attention in the matter of mowing and burning. It is not known whether or not any- thing is to be gained by early sowing, which, besides, is apt to invite the attack of Hessian fly. THE CAPTIVE ISOSOMA. (Isosoma captivum Howard. Fig. 11.) Very little is known of the habits and transformations of this species. I found it in a field of growing rye near Normal, Ill., May 10, 1884, and swept it from pmatne and bluegrass about Lafay ae Ind., during May, 1885, and again during the same month in 1886. Dr. J. A. Lintner reared both sexes from wheat straw sent him from Johnsons Creek, Niagara County, N. Y., in December, 1887, the adults appear- Fic. 11.—Jsosoma captivum How.: adult (from Howard). ing in March of the following year, the straw havihg, presumably, been kept indoors during the winter.“ Probably the adults occur normally at about the same time as those of /sosoma horded, tritici, and elymi. We know that it attacks wheat, probably rye, and peraed barley. DESCRIPTION. ‘Female. —Length, 3.4 mm.; expanse, 5.8 mm. Head and mesonotum uniformly, finely, and closely rugulose, not shagreened; metanotum more coarsely rugulose and with a narrow and shallow central longitudinal groove, which widens slightly pos- teriorly; pronotal spot plain, moderately large; hind cox delicately punctate. «Fourth Report, State Entomologist of New York, p. 34. 35 Abdomen shiny, as long as thorax, oblong-ovoid; the second segment occupying nearly one-third the whole surface; segments 4 to 6 subequal, the third a little shorter; funicle joints 2 to 5 subequal; club nearly as long as three preceding joints; joint 1 one-half longer than 2; pile sparse and short, more marked at metanotal fim- bria and terminal joints of abdomen than elsewhere. Color uniform black, except for pronotal spot, tarsi, middle and hind femoro-tibial knees, front tibse and apical third of front femora, which are light honey yellow. Stigmal club about as in I. hageni and J. agrostidis, except that its tip is more rounded instead of squarely truncate. ‘‘ Vale.—Length, 2.5 mm.; expanse, 5 mm. Punctation rather finer than with female; petiole as long as first abdominal joint, strongly rugose; flagellum of anten- nz long; pedicel not globose, slightly elongate; joint 1 of funicle longest, twice as long as pedicel; joints 2, 3, 4, and 5 each a little shorter than its preceding joint; not so strongly pedicellate as with J. californicum and I. bromi, moderately arched above with hairs arranged in two indefinite whorls; club separated into two subequal pedicellate joints, giving the funicle the appearance of being 6-jointed instead of 5-jointed, as with bromi and californicum; scape short, about as long as pedicel and first funicle joint together; strongly expanded below tip. Coloration like that of the female.’’ (Howard, Tech. Ser. 2, Div. Ent., U. 8. Dept. Agr., pp. 15, 14, 1896.) The earlier stages of development are unknown, but they probably differ little from those of allied species. Quite likely the same natural enemies prey upon it and the same repressive measure will apply to it as with the preceding species. WEBSTER’S ISOSOMA. (Isosoma websteri Howard. Fig. 12.) This is in all probability a wheat-infesting species, as I found it in a wheat field near Bloomington, Ill, May 9 and 11, 1884, and about Lafayette, Ind., also in fields of wheat, June 2 and 16, 1885. I also Fie, 12.—Isosoma websteri: adult female—much enlarged (from Howard). reared it from a pupa taken from a growing wheat plant in the Bloomington, IIl., field May 29, but have not encountered it since in my studies of these insects, Nothing is known of its life history 36 except what I have just given. Its close resemblance to /. maculatum, which I have reared from stems of cheat from the vicinity of Cham- paign and Urbana, IIL, is quite suggestive, the adults of this last species being abroad during late May and early June in the same localities. DESCRIPTION. “ Female.—Length, 3.4 mm.; expanse 6.3 mm. Head, pronotum and mesonotum as with I. maculatum; metanotum with only the beginning of a central furrow, its lateral carinzee immediately curving around the sides, each inclosing an oval, flat- tened, nearly smooth portion of the metascutellum; a median carina extending nearly to the tip of the sclerite; pronotal spot moderately large and plainly seen from above, occupying a little more than one-third of the dorsal aspect of the pro- notal foreborder. Abdomen much longer than the thorax; segments 3 to 5 increasing in length; 6 and 7 as long as 5. Antenne with joint 1 of the funicle twice as long as 2; joints 3, 4, and 5 gradually decreasing in length, subequal in width; joint 5 more closely connected with club than with the preceding joint. Color and wing venation as with J. maculatum.’’ (Howard, Tech. Ser. 2, Div. Ent., U. S. Dept. Agr., pp. 15, 16, 1896. ) While, as stated, this is probably a wheat-infesting species, it is to be remembered that it has been reared only in a single instance, and it is within the range of possibility that my growing wheat plant, as I supposed, might possibly have been cheat, as it is easy to confuse the young plants, and as the two grow everywhere intermixed in the fields mere collecting offers no solution of the problem whatever. Of the four species of /sosoma which I have reared from common cheat (Bromus secalinus), viz, I. elymi, I. albomaculata, I. hirtifrons, and I. maculatum, none were found in the wheat straws growing in the same field. Should the species become numerous enough to cause serious depre- dation it will probably yield to the same repressive measures as the other grain-attacking forms. THE HAIRY-FACED ISOSOMA. (Isosoma hirtifrons Howard. Fig. 13.) The type specimens of this species were reared from rye. straws collected by Mr. Coquillett, in Mercer County, Cal., in 1885. It was reared by myself from stems of common cheat growing in a wheat field near Urbana, Ill., in 1902. I know nothing whatever of its life history except that it appeared in my breeding cages in common with the other cheat-infesting species. The records of the Illinois State Laboratory of Natural History and those of the office of the State entomologist contain numerous references to Isosoma attacking rye. 37 Specimens of the affected straws show that a part of this injury was due to /sosoma tritici, whose presence could be detected by the larval cells in the walls of the straw; also many straws were attacked by ¢ noncell-making species, the larve being in the center of the stems immediately above the joint. No adults were reared, as the larve were supposed to be those of the old /sosoma tritici Riley, which is not now known to attack any grain except wheat. It is therefore impossible to say which of the species whose larve live in the cen- ter of the stem it was that did the injury in these cases. I made every effort to secure material from the fields of rye about Urbana and Champaign, Ill., during the summer of 1902, but was unable to find any infested straw, and therefore can throw no light upon the identity of the rye-attacking species; but the fact that the one under consideration is known to affect rye in California would place it under FiG. 13.—Isosoma hirtifrons How.: adult female, much enlarged (after Howard). suspicion wherever it occurs in the eastern States. I judge that it will be very easily confused with other species, and the fact of its infesting cheat would lead to the suspicion that it will be found infest- ing other grasses. DESCRIPTION. ‘“Female.—Length, 3.7 mm.; expanse,7 mm. Sculpturing of head, pronotum, and mesonotum as in J. websteri, except that there are sparse, large, shallow punctures on the mesoscutellum; cheeks much fuller than in other species; metanotum as with J. maculatum. Abdomen about as long as thorax; segments 3 to 6 increasing in length. “Antenne stout, moderately long, very hairy; proportions about asin I. websteri. Body not unusually pilose, except face, which is closely covered with short white pile; pro- notal spots very plain, but not large, occupying about one-third of the dorsal aspect of the fore-border of the pronotum. Color black, except for all femoro-tibial knees and pronotal spot. Claw of stigmal club given off some distance from tip, delicate and short.”” (Howard, Tech. Ser. 2, Div. Ent., U. 8S. Dept. Agr., p. 16, 1896.) 88 Up to the present time cheat has been looked upon only as an undesirable plant growing among wheat like weeds among corn, but it now appears to be doubly undesirable on account of its harboring insect enemies of cultivated grains. ISOSOMA SECALE Fitch. This was described by Doctor Fitch in 1861, after he had become fully convinced that these insects were not parasitic but the true depredators among grain.“ I have not myself encountered it in the study of grain insects, but from the statements of Doctor Fitch it does not seem to differ in habits from /sosoma hordei and J. tritic/, and one can not help sus- pecting that a careful study of its life history and development will show that it is one of these species. It was given the common name of ‘‘rye fly,” and adults were reared from straws grown in 1860, emerging about the Ist of June, 1861. The larvee were found to occupy cells in the walls of the rye straw, and not in the base of the sheaths, as was supposed to be the case with Z. hordez, though Doctor Fitch describes ‘‘ the disease which the insect causes in the rye being in every particular like that in barley and wheat.” As we now know, barley and wheat are attacked by two different species, but all three seem to have precisely the same life history, so that whether there be one species or more, the farmer will be able to meet it or them with the same preventive measures. © DESCRIPTION. ‘‘ Female.—Length, 3.6 mm.; expanse, 6.6 mm. Punctation as with J. hordei; pro- notal spot large, plainly seen from above. Abdomen as long as head and thorax; segments 4 and 5 subequal; 6 and 7 together shorter than 5; 2 much longer than 4 and 5 together. Color black; scape and legs black; front tibize, knees, and tips of middle and hind tibiz and all tarsi honey yellow; claw of stigmal club given off near tip of club, somewhat curved; antennie as in J. hordei. ‘‘Male.—Length, 3mm.; expanse,5 mm. Specimen in poor condition. Expansion of scape more abrupt from tip than with other males described; funicle joints well arched above, scarcely pedicellate, each with 2 indefinite whorls of hair and with no median constriction; each joint twice as long as wide; club plainly divided into two joints, but no trace of pedicel to terminal joint, resembling J. hordei in this respect; petiole a little shorter than hind coxz and shorter than first abdominal segment.”’ (Howard, Tech. Ser. 2, Div. Ent., U. 8. Dept. Agr., p. 19, 1896.) In this connection it may not be out of place to state that I have reared an undetermined species of Isosoma in connection with /. hor- dei from the stems of Llymus canadensis, growing near Champaign, Ill., and seeming to affect the grass much in the same manner as a@Seventh Report Noxious and other Insects of New York, pp. 849-851. 39 that species. It may on further study prove to have some connection with the one now being discussed, though I have not found it attack- ing rye. FITCH’S ISOSOMA. (Isosoma fitchii Howard. ) This is the last of the described Isosomas known to attack growing grain, though I have reared what appears to be still another from wheat straws from Carbondale, Ill.; but the specimens are still undetermined and nothing definite can now be said of them. This species was described from 2 females and 1 male found in-the Fitch collection, labeled in Fitch’s handwriting, ‘‘ Hwrytoma horde: Harris, Nos. 15223 and 15197.” Nothing whatever is known of its habits, but it was presumably reared, with some other species, from grain. DESCRIPTION. ‘“« Female.—Length, 3 mm.; expanse, 5.8 mm. Head, pronotum, and mesonotum faintly shagreened, nearly smooth, shining; mesoscutellum with a few sparse pune- tures; metanotum with a complete median longitudinal furrow emarginate on the anterior half and with a central carina extending nearly to tip; very coarsely rugu- lose either side of the furrow with a faint granulation between raised lines; pronotal spot large, plainly seen from above, and two spots together occupying about one- third of the dorsal aspect of the foreborder of the pronotum. Antenne with well- separated joints; funicle joints 2, 3, 4, and 5 equal in length and width; joint 1 a little longer; joint 5 as well separated from the club as from preceding joint; club a little longer than 4 and 5 together, but of the same width. Abdomen as long as the thorax; joint 4 shorter than 6; 5 longer than 6; 7 and 8 subequal. Color black, except for pronotal spot and knees, which are luteous; claw of stigmal club given off about at tip of club, straight. ‘¢ Male.—Length, 2.2 mm.; expanse, 4.2mm. Petiole about as long as hind coxee and nearly equal in length to first abdominal segment. Antenne with funicle joints - very slightly arched above, each joint fully three times as long as wide, and slightly constricted in the middle; otherwise as with J. hordei.’’ (Howard, Tech. Ser. 2, Div. Ent., U. 8. Dept. Agr., p. 20, 1896. ) I have now treated all of the species of these insects known to attack cultivated grains in this country, though there may be still others as yet unknown. These known species have been described in each case, not especially for the benefit of the unentomological farmer, but because this publication will go to many lands and into the hands of many dif- ferent peoples. Some will care nothing for descriptive matter, and such can easily pass over it in the use of this bulletin, but there will be others who will look to its pages for aid in determining with exact- ness the identity of the species which they may have before them, and for these descriptions are a necessity. Some of the species included may appear to be of no especial interest to the practical farmer, but of this no one can confidently predict. It may be true to-day and not 40) true to-morrow, for no one can tell what year or in what part of the country any one of these, even the one that seems the most insignifi- cant, may suddenly come to the front and commit serious depredations over a considerable area. Besides this, they are all of them so obscure in appearance and their effect on the plants they attack so subtile and hidden from the eyes of the farmer that he is unaware of his loss until on threshing his grain he finds that it does not turn out well and the kernels are light and shriveled. It is like the thefts of a trusted offi- cial—they are not missed until, by accident, perhaps, the defalcations are discovered, when we are struck with amazement at their magni- tude and ask ourselves and each other how it is possible for such things to go on continually through a long series of years and escape detection. The financial loss occasioned by an unusually disastrous outbreak of these pests can be estimated, but it is a mistake to sup- pose that such losses constitute more than a very small percentage of the amount annually fileched from the farmers by these insidious foes of his crops. It is not so much the big losses that occur at rare inter- vals, and of which we read much in the public press, but the infinite and perpetual leaks from this source that pull down the farmer’s profits— leaks that, as has been shown, he may readily prevent in a most inex- pensive manner. It is for the very reason of their obscurity and insidious attacks, coupled with the magnitude of the losses caused by them through a long series of years, that has prompted a study of their habits and the publication of the facts in the present form. THE TWO-WINGED GRAIN AND GRASS FLIES. The insects included under this head are true flies, having only two wings and their young are maggots without feet, eyes, or jaws. They belong to the family Oscinide, containing a large number of species with variable food habits, some of them not attacking plants, but living on the cast skins of other insects, shells of insect eggs, and in the bur- rows made in plants by other insects. Some of them are leaf-miners, others live in galls on grasses, while still others live underground on the roots of plants. Still others, that are known to live in the stems of grain and cause more or less destruction by their attacks, will be here considered, though it must not be supposed that there are not still others of such depredators of which we as yet know nothing. Our grain-affecting species are to be found in the genera Meromyaza, Chlorops, Elachiptera, and Oscinis. It is to the last that the very destructive frit-fly (Osein?s frit) of England and Europe belongs and which is so terribly destructive to grain crops in those countries. The habits of Meromyza americana have been pretty well studied and we now have a fairly good knowledge of its life history and habits; but of the most of the other species belonging to the above genera we only SE ee 41 know that they attack the stems of wheat and other smaller grains, but we are far from possessing a full knowledge of their life cycles. Chlorops proxima Say is known to attack wheat plants in Kentucky, flies emerging in May; I have reared Elachiptera longula Loew from maggots in the stems of Panicum crus-galli in Illinois, the flies in this case appearing late in August, and from both wheat and oat plants in Indiana. It has also been reared from oats in Ohio by Prof. W. B. Alwood. From wheat plants in Indiana I have reared /lachiptera nigricornis Loew, and from the same lot of plants I reared also /. costata Loew, the latter having been reared from oats in Ohio by Professor Alwood and from maggots found ina decayed cavity in the roots of living garden radish in Illinois by Mr. Coquillett. The extent to which the larve of the last species attacks and destroys wheat plants is uncer- tain, for though I have reared them from volunteer wheat plants grow- ing up in the fields I have never been able to separate their maggots from those of Oscinis. I have reared Oscinis trigramma Loew and O. coxendix Fitch from volunteer wheat plants in Indiana, and OQ. dorsata Loew, 0. covendix Fitch, O. wnbrosa Loew, and O. trigramma Loew from August-sown wheat at Wooster, Ohio. —Oscinis carbonaria Loew is treated in this paper under the head of the lesser wheat-stem maggot. The larve of all of these except Meromyza closely resemble each other, work in the young plants, and, some of them at least, destroy the cen- tral stem before the plant tillers or individual tillers afterwards. The larve or maggots are small, yellowish white, pointed anteriorly, but more blunt at posterior extremity, without jaws, but provided with a pair of minute hooks whereby they rend the tender growth of the plant and extract the juices. They may generally be found in the midst of their work surrounded by the injured tissue and grass saturated with the sap of the plant, and later on the brown puparia may be observed about the bases of the young plants in late fall and even outside the sheaths, and scattered on the ground in spring. They are often mis- taken by farmers for the ‘‘ flaxseed” or corresponding stage of the Hessian fly. WERE PROBABLY ORIGINALLY GRASS FEEDERS. Beyond a doubt the larve of these flies were originally grass feed- ing, and we find them at present developing in the stems of grass, but seemingly preferring grain at times, probably when the grain at the time of oviposition offers a more inviting place for the female to deposit her eggs with the assurance that her offspring will be within reach of an ample supply of food. Until the last half of the last cen- tury the average farmer paid little attention to such matters, and, as the flies were as now less thoroughly studied than other insects, there was little to encourage the entomologist in attempting to study their habits, as it is rather a thankless task to rear them and get their life 42 history worked out only to learn that the species can not be deter- mined, and the information thus gained is thus rendered practically worthless because of not being able to state definitely which of the many forms one has been studying. Only recently I have learned the name of a species reared from grass stems eighteen years ago. For this reason even now the earlier stages of nearly all of those reared from growing grain are obscure or unknown, the flies having simply been reared from grain or grass, but the young of any particular species can not be separated from those of perhaps a half dozen other similar flies. There is much need at present of careful studies of these insects with a view of determining their exact relation to agri- culture, and especially to what extent they may be combated outside the grain fields of the farmer. At present not more than one farmer out of a thousand knows of their existence, and the injury they do is attributed to the Hessian fly, thus to a certain degree throwing obscurity over all reports of the ravages of the latter insect, which can not be reached outside the grain field, while some at least of these other flies surely can. When I began to study the life history of the lesser wheat-stem maggot, in 1884, it was the most unsatisfactory and, at that time, to all appearances, the most unprofitable piece of work that I ever undertook, for the reason that it was impossible to separate it from other similar species; but this has now been largely overcome with this insect, and we know that much can be done to prevent its injuries. EARLY REPORTS OF INJURIES TO GRAIN. One of the earliest reports of injuries to grain in this country that can be attributed to these insects with any degree of certainty was cited by A. S. Fuller, from the works of M. Du Hamel du Menceau (New Hamburg edition of 1759), as follows: There is a smaller kind of worm which gets into the roots, chiefly oats, and work- ing upward destroys all the inside of the plant, which perishes soon after. I sus- pect it to have been an insect of this kind that destroyed so much wheat in the neighborhood of Geneva, and which M. de Chateauvieux described thus: ‘Our wheat in the month of May, 1755, sustained a loss which even that cultivated accord- ing to the new husbandry did not escape. We found in it many little white worms, which afterwards became a chestnut color. They post themselves between the blades and eat the stems. They are usually found between the first joint and the roots. Every stalk which they attacked grew no more, but became yellow and withered. The same misfortune happened to usin the year 1732. These insects appeared about the middle of May and made such havoc that the crop was almost destroyed.”’ The attack on oats was clearly that of the stalk borer or heart worm, the caterpillar of the moth Papaipema (Gortyna) nitela Guen., but that in the wheat does not accord with the work of any other than of some of these small grain and grass flies under consideration. Mero- 43 myza maggots do not turn brown or ‘‘chestnut colored,” and those of the Hessian fly, even if it were known to occur in America at that early date, do not eat off the stems. As early as 1822 Mr. James Worth, of Bucks County, Pa., seems to have reared these flies from maggots attacking wheat. It is therefore probable that as the area of cultivation increased in this country these insects have gradually transferred their atten- tion from grass to grain as a matter of necessity, and though more or less numerous every year in the grain fields, they become excessively so when the grass conditions are less favorable than those of the grain; but the grasses are a continual source of supply from which the grain fields are colonized. These interrelations may be more or less cur- tailed by the farmer with but little expense. THE GREATER WHEAT STEM-MAGGOT. (Meromyza americana Fitch. Fig. 14.) - PAST HISTORY OF THE INSEOT. This is in all probability an insect native to the far South, as it occurs in Mexico and northward over the entire United States and far into British America, its food plants, before the advent of the Cau- casian farmer, being the wild grasses. The fly was described in 1856 under the name here applied, but without definite proof of its attack- ing grain further than that it was collected in wheat fields and closely resembled the European species Meromyza saltatrix Linn. There is now, however, considerable evidence of its having attacked growing wheat at least as early as 1822 in Pennsylvania“ and in 1845 in Michi- gan.” The evidence furnished by Mr. James Worth, of Bucks County, Pa., indicates that three broods were observed, as he calls attention to the attacks of ‘‘a little worm found in the lower part of the stalks of wheat and rye in spring and fall and about the joints in June.” Of these larvee he says that ‘‘some were pale yellow, with brown spots about the mouth,” which would imply that they were those of some species of Isosoma; but he further states that one kind was found in volunteer wheat, which the Isosomas do not attack, and their larvee are not found in the plants in fall, and in case of only one, with a possibility of another species, are they to be found in the plants in spring. While Mr. Worth evidently was not able to separate the ditferent species of the larve found in growing grain, his careful descriptions and exactness in locality and dates are exceedingly val- uable and enable those familiar with the forms of which he writes to recognize them with reasonable clearness. Hence we are left with little doubt that he observed the larve of Isosoma and Meromyza «The American Farmer, vol. 4, p. 394; Memoirs Penn. Agl. Soc., Vol. 1, p. 165. 6 Prairie Farmer, Sept., 1845, p. 216. +4 without separating them, and also in fall, including those found in volunteer wheat, this latter species and other Oscinidee. The reference in the Prairie Farmer seems to have been drawn out by a notice in the Michigan Farmer of a new wheat insect in that State, described as the product of a greenish fly about three-sixteenths of an inch in length, whose larva is a white worm one-fourth of an inch long, ribbed, without feet, with two forked lines on its forehead, found in the straw above the upper joint, where it devours the juices which would otherwise ascend to the head, but which denote the presence of the worm in the straw by turning white prematurely when the grain is in the milk. There is also here reference to the presence of ‘‘9 eggs * * * found in a single straw, one of which had just hatched,” but which eggs, so called, are now known to have been the bodies of a minute parasitic mite, whose rounded form is not unlike that of an egg and which is occasionally found attacking the maggot in the straws. Doctor Fitch did not rear the flies which he described, but collected this in connection with several species of Oscinis by sweeping in the wheat fields with an insect net. Being familiar with the grain attacking habits of ; similar insects in Europe, Sr ioe he expected, as he says, to Fic. 14.—Greater wheat stem-maggot (Meromyza americana): Year the flies from the ga yb ergata ineied heel te growing hal fame different seasons, but fail- ing, as he states, to do this, contented himself with describing the flies without attempting to connect them with the injuries which he clearly observed. Nothing further appears to have transpired relative to this insect until in the year 1867, when Doctor Riley reared the fly from larve working in the growing stems of wheat, immediately above the upper joint, in the month of June, and in Missouri. In this case the flies appeared during the first week of July, after a pupal period of twelve to fourteen days. These facts were published in the Rural New Yorker for January 28, 1869, and in his first report as State entomol- ogist of Missouri he discussed the insect and gave illustrations of the adult, larval, and pupal stages, but does not appear to have suspected the occurrence of a second brood later in the season. In 1876 a farmer of Hinckley, Ohio, reported it as attacking his spring wheat. We «Country Gentleman, July 27, 1879. 45 also hear of it during this same year in the State of New York, where stalks of growing wheat containing the larvee were sent to Doctor Lint- ner, from Scipioville, in August. Some of these stalks contained larve, and some of the flies were observed crawling about on the table where the package had been unwrapped, and these were supposed to have emerged from the straws while in transit. Doctor Lintner adds nothing to our knowledge of the species at this time, but gave it the common name of the wheat stem-maggot in preference to Doctor Fitch’s American Meromyza.¢ In March, 1883, Dr. 8S. A. Forbes, State entomologist of Illinois, received information of serious injuries to young wheat in Fulton County, of that State, and on investigation found the depredator to be a small, slender maggot which attacked the plant just above the root, thereby killing it. Farmers in the infested territory had noticed the injury during the preceding November and December, but had not taken steps to learn of its destructive character until, with the coming of spring, the pest seemed to break out anew. From larve taken from infested plants from these fields puparia were obtained April 30, and the flies began to appear by May 4, and continued to emerge until June 1, thus showing that the insect might do serious damage to young wheat in the fall, pass the winter in the maggot stage, and resume its work of destruction again in spring. This, taken in connection with what had been observed by Riley and Lintner, showed plainly that the flies emerging in May and June oviposited in the growing stems of the wheat, and the jarve hatching from these eggs entered the stems just above the upper joint. Doctor Forbes, in his thirteenth report as State entomologist, gave full details of his observations and called attention to the possibility of a third brood developing in midsummer, and also gave the insect the common name of the ‘‘ wheat-bulb worm.” During the summer of 1884 I was engaged as a special agent of the Division of Entomology, under Doctor Riley, and from June 1 to Octo- ber was located at Oxford, Ind., engaged in the study of grain insects, especially those attacking wheat. From straws taken from a field near Oxford I reared adult flies up to July 26, and volunteer wheat, taken from this same field September 5 and sent to Washington, gave adults September 11, 13, and 16, according to the divisional notes. During the same year adults were reared from volunteer wheat October 1 and found in the field of young wheat on October 6.° In 1886 Doctor Forbes put the final touch, so to speak, to the settlement of the occur- rence of this midsummer brood by finding both eggs and larve on August 4 in volunteer wheat, and in his fifteenth report (p. 39) con- structed a calendar showing the periods covered by the several broods. @Loc. cit., Vol. XLIV, p. 535, 1879. 13th Rept. State Entomologist of Illinois, pp. 13-29, 1884. ¢ Rept. U. S. Comm. Agr., 1884, p. 390; Bull. 9, Purdue Univ., Oct., 1886, 46 This calendar shows our combined work on the insect, and is all the more valuable on account of our having worked entirely independently of each other over territory within the same latitude, and with other conditions in every way similar. It is also a matter of interest that on February 27, 1891, I collected all stages of the insect except the egos in wheat growing on the grounds of the Agricultural College of Texas, at College Station. LIFE HISTORY. Throughout the region of latitude 40° N. the insect is three-brooded, although there may be but two in the north and more than three in the far south, though Doctor Fletcher states that about Ottawa, Canada, about latitude 45° N., there are three broods, the adults appearing in the beginning of June, the end of July, and again late in September. My observation in Texas, about latitude 30° 30’, does not necessarily indicate additional broods, as there may be, as with the Hessian fly, a prolonged summer resting period, during which the insect is continued in a stage requiring no food and incapable of reproduction, until the vegetation upon which the larve are dependent for their food supply begins to take on new life, and, as with the Hessian fly, we may find that the very conditions that serve to prevent the starting up of the fresh growth of vegetation, so essential to the life of the young larve, has also the effect of retarding the emerging of the parent insects. Such problems as these are for National investigation, where imaginary lines and political boundaries do not enter into consideration. Within the wheat belt of the United States, broadly speaking, the life cycle of this insect is as follows: The winter is passed in the larval stage, and the short pupal stage coming in May brings the emerging of the adults at the time when the female is able to place her eggs on the plants where the young, on hatching, will make their way to the tender and succulent stem just above the upper joint. By the time the straw has ripened the larve have ceased to require food, and pass through the pupal stage, the adults of this brood appearing in July. Eggs are now deposited in volunteer wheat and grass, and, owing either to the retard- ing effects of meteorological influences or a diversity of food of the larvee or both, perhaps, the emerging of the adults is prolonged throughout a period extending from late August through September until late October. At this period the fall wheat offers a decidedly inviting plant to the female fly on which to place her eggs with a prospect of her progeny having an abundant food supply. It is the larve from egos deposited during this period that winter over in the plants and give rise to the May-June generation of flies. It is this last brood that is of more especial interest to the farmer, as it is very seldom that the pest does serious injury to grain except in fall and early spring. : : q ; ; ‘ : : j : . 47 DESCRIPTION. Adult.—Length, 0.17 inch to tip of abdomen and 0.20 inch to end of wings. Color, yellowish white, with a black spot on the top of the head, which is con- tinued backward to the pedicel of the neck. Thorax with three black stripes, approaching each other anteriorly, but not coming in contact, the middle stripe pro- longed anteriorly to the pedicel of the neck and posteriorly to the apex of the scutel. Abdomen with three broad, blackish stripes, which are confluent posteriorly and interrupted at each of the sutures. Tips of the feet and veins of the hyaline wings blackish. Eyes, bright green. Antenne, dusky on their upperside. (Lintner.) Egg.—Snow white, fusiform, longitudinally ridged, the space between the ridges being concave and marked off into rectangular areas by still slighter ridges transverse to the others. Length, 0.023 inch; breadth, 0.005 inch. (Forbes. ) Larva.—Very pale green, slender, footless, tapering anteriorly, somewhat nar- rowed, but subtruncate posteriorly; one-fourth of an inch in length by about one- eighth of an inch in width. The segments are thirteen in number, including the head, those in the center of the body being a little wider than long. The four ante- rior segments narrow rapidly forward, the one next the head being at its apex less than half the diameter of the fourth. The three posterior segments are also some- what narrowed, the penultimate being about three-fourths the diameter of the sec- ond preceding. The head is provided beneath with the pair of black toothed hooks common to many dipterous maggots. The antennz are very short, scarcely longer than broad, two-jointed, the second joint extensile. There are two circular, appar- ently sensory, areas below the antenne upon the front of the head, doubtless repre- senting maxillary palpi. The mouth is beneath the head, sucker-like in form. The last or anal segment is divided into two lobes and bears upon its posterior surface two breathing pores or spiracles, each guarded bya circlet of about twelve depressed spines. The surface of the larva is entirely smooth and shining, except for some very fine transverse ridges on the under side of the segments, evidently used in loco- motion. On each side of the base of the second segment is a small, gill-like append- age, divided into two lobes, each lobe with six divisions. ( Forbes.) Pupa.—The pupa of this species is what is technically known as a coarctate pupa, contained within the last skin of the larva, which is not shed previous to transfor- mation, but remains as a protective envelope for the forming pupa. As the latter shows through its case, the color is green, except at the ends, where, with the growth of the pupa within, the case is left empty and transparent. It is about one-sixth of an inch long by one-fifth in width, and divided into ten clearly recognizable segments. The anterior of these, corresponding to the head and first segment. of the larva, is yellowish, shrunken, and corrugated, about half the width of the third segment. The second and third are obscurely divided, the first being short and narrowing rapidly forward. Within it are observed the retracted maxillee of the old larva. The remaining segments to the eighth are about equal in length, separated by deeply impressed sutures at first, the anterior sutures becoming obliterated as the enlargement of the head and thorax of the pupa within distends the envelope. The ninth segment is the longest of all, the tenth being nearly equally long, but narrower, and shrunken and wrinkled on its posterior border. The eleventh, representing the twelfth of the larva, is only a brown and corrugated rudiment. As the development of the pupa approaches completion, the eyes, wing-pads, and legs are visible through the transparent covering, but they form no elevations of the surface. (Forbes. ) FOOD PLANTS. Besides wheat, rye, oats, and barley, all of which it has long been known to infest, I have reared Meromyza americana from the com- 48 mon bluegrass (Poa pratensis), while Doctor Fletcher, in Canada, has reared the flies from maggots in the stems of Agropyron, Deschampsia, Elymus, and Poa, and as he states that the flies are enormously abun- dant in meadows and prairies all the way from northern Quebec through the Lake Superior region, Manitoba, and the Northwest Ter- ritories, there seems to be ample proof of its ability to sustain itself without trouble among the grasses of that country. The extent to which it attacks fall wheat in autumn is entirely obscured from the fact that, in the majority of cases, it is confused in its work of destruction with the Hessian fly. In Ohio, at a time when the Hessian fly was being accused of devastating whole fields of wheat in the fall, by collecting a great number of the affected plants at the beginning of winter and placing them in the insectary I reared fully as many of these as I did of the Hessian fly, which at that time I was especially engaged in investigating. It is on this account that the entomologist who attempts to study the economics of the Hessian fly, which does not breed in the grasses, will find the greatest difficulty in weighing the evidence offered by those who can not or will not note the difference in the nature of these insects and the great similarity in the final effects of their attacks upon growing fall wheat in autumn and spring. SELECTION OF FOOD PLANTS BY THE ADULTS. Kither some varieties of the same kind of grain are more or less repugnant to the flies, or else they possess a very finely adjusted sense of the Jarval preferences for certain other varieties, for they certainly exhibit a considerable discrimination in their selection of the different varieties of wheat on which to place theireggs. Doctor Forbes has called attention to the fact that the most seriously injured fields of wheat in Fulton County, Ill., in 1883, were of the Fultz variety. At Lafayette, Ind., June 14, 1889, among a lot of experiment plats on the experi- ment-station grounds, sown side by side, on the same day, with the same soil and other conditions, there was a marked difference between the number of affected straws in the Velvet Chaff and in the Michigan Amber, the infestation being fully four times greater in the former than in the latter. Even in the case of larger fields bordering each other the conditions did not vary, and where the two varieties over- lapped along the margins the same partiality for the Velvet Chaff had beenshown. Doctor Fletcher has also noted a strong prejudice in favor of some varieties of the same kinds of grasses. For instance, while Poa serotina was one of the most seriously affected of all of the grasses, P. pratensis, P. cesia, and P. compressa were almost exempt from attack. Attack on Setaria viridis was observed in a single instance. PLACE AND METHOD OF OVIPOSITION. According to Forbes, the eggs are placed on the stemsof grain, *‘some being pushed down beneath the ensheathing bases of the leaves and 49 others cemented to the stems just at the margin of the sheath, while still others were placed along the edge of the sheathing base of the leaf, sometimes being thrust under the edge.” This agrees with my own observations and is doubtless the usual method of oviposition, as the main object on the part of the female is to place the eggs where the young larve will the most easily reach the tender, juicy stem as soon as possible after escaping from the egg, and is probably true in the case of grasses as well as of grain. METHOD AND NATURE OF ATTACK. Both Doctor Lintner and Doctor Forbes have endeavored to indicate this by the selection of explanatory common names for this insect. The former, disregarding Fitch’s name, American Meromyza, as too tech-' nical, and having observed the larve in the full-grown straws only, gave it the name of the ‘‘ wheat-stem maggot,” while Doctor Forbes, having first encountered the larve in the bulbous lower stem in early spring, gave it the name of the ‘‘ wheat-bulb worm,” on account of its resemblance to the *‘ wheat-bulb maggot” (/Zylemyia coarctata) of England. It is really a maggot and affects the stems of the plants which it infests, besides being the largest maggot of this kind at present known to attack the stems of grain in this manner in this country; hence, in order to distinguish it from other smaller stem maggots, I have here termed it the ‘‘ larger wheat stem-maggot.” The larva has no jaws or mouth, but a couple of hook-shaped appendages by which it tears the plant and feeds from the juices, the cavity made by this destruction of the stem being filled by a pomace- like mass in which the larva is to be found. The effect on the plant is shown by the accompanying illustration (fig. 14, 7). In young plants the central spindle-shaped enfolded leaf is killed, precisely as with attacks of Oscinis larvee, the detached portion turning first yellow and later brown, then shriveling up and dying, leaving the outer lower leaves uninjured. In Hessian-fly attacks this spindle-shaped leaf is absorbed and does not appear at all in young wheat in autumn, so that there need never be any confusion of the work of these two insects in fall wheat, and the effect on the full-grown straws is even more easily distinguishable. When attacked by the maggots of this species the fully grown straw withers at the upper joint and all that portion of the stem including the head, the sheath excepted, changes to a whitish color, the remainder of the plant, including the upper sheath, continuing uninjured and of the usual green color. The Hes- sian fly never affects the full-grown straws in this manner and the lesser wheat stem-maggot does so but rarely, so that the presence of these maggots in the straw can be easily detected shortly prior to harvest by their whitened color from the upper joint upward. The larve are within the stem and not outside and under the sheath, as 7327—No. 42—038——4 50 with the Hessian fly; they are larger and of a more glassy green color than those of the lesser wheat stem-maggot, and it is only when still very young that the ordinary farmer need ever mistake them for any of the others mentioned in this bulletin. It is only in the manner of killing the stem of young wheat that it need be confused with others. EXTENT OF RAVAGES. Though present in the fields every year, as is witnessed by the whitened heads of grain in the fields just prior to harvest, I have never known a serious attack at that season of the year; nor is there any- thing at present to indicate that it is likely to work more serious injury at this season in the future than it has in the past. Its ravages in the young wheat in fall and spring, as illustrated by the outbreak in Illinois in 1882-83, are not as yet of usual occurrence, though several similar instances have come to my knowledge within the last: twenty years. In two cases—one in Indiana in 1888 and another in Ohio in 1900—the fields were also badly infested by Hes- sian fly, but from the material reared it would seem that this species was to be credited with no small percentage of the loss. Occasionally fields of fall wheat, especially if sown early, are attacked in the fall and ruined by this insect alone, though the damage is in some cases attributed to the Hessian fly. It is, however, easy enough to detect the difference between injuries caused by these insects, as has been explained under methods of attack. PREVENTIVE MEASURES. The liability of attack from this insect is not sufficiently great to warrant any expensive measures being put forth in order to forestall possible outbreaks. As yet, we have no way of foretelling these sud- den attacks, as the pest has never proven excessively abundant in the same locality two years in succession. The fact that late-sown wheat is less subject to injury, and in cases where the two have been found in a combined attack, the grain has been sown early, indicates that this now-accepted method of warding off an attack of Hessian fly will work equally well with this species. There is nothing at present to indicate any change from these conditions throughout the winter-wheat grow- ing regions of the Northern States. Whether or not the same rule will apply in the South remains to be seen, as we know too little of © the pest in that portion of the country to be able to speak positively. In the North, in the regions devoted to the raising of spring wheat, it would appear that a burning over of the grass lands in winter would reduce the probabilities of attack. The destruction of volunteer wheat, which should be done in any case as a protective measure against attacks of Hessian fly, will of course tend to reduce the probability of the young wheat being attacked in autumn. It must be borne in mind, 51 however, that this is a grass as well as a grain insect, and eradication from the grain fields will not protect from infestation from without. NATURAL ENEMIES. The abundance of one of these and the extent to which they are able to perform their deadly work is a most encouraging feature, viewed from the standpoint of the husbandman. A small, shining black, four-winged fly, with reddish-yellow legs (Celinius meromyze Forbes), is exceeding beneficial in its parasitic work on the maggots of this pest. This parasite was discovered and described by Doctor Forbes in connection with the investigations of the outbreak in Illinois in 1883. So abundant is this parasite that it is almost impossible to rear the flies from the straws in July without also rearing numbers of these diminutive friends. They attack the maggots by placing their eggs in their bodies, and the eggs hatching feed upon the maggots and destroy them. This parasite occurs generally with the depredator, even in the far North. Another natural enemy is the mite Pediculoides (Heteropus) ventri- cosus Newport, illustrated on page 22. The young of this insect are so very minute as to be quite invisible to the unaided eye. They are without wings, but very active, and make their way to the maggot working within the stem and fastening themselves upon it suck its blood, in the meantime themselves increasing rapidly in size until they appear like minute globular eggs, the abdomen being distended with young, as there are no males, and the body having much the proportions the stem has to the pumpkin. Each female gives birth toa great number of young, which at once either escape to other stems to hunt out their victims or else settle down with the parent. These are frequently found attacking the maggots and are apt to escape detection, or, if observed, mistaken for eggs. The reference in the Prairie Farmer, calling attention to the presence of what probably were these maggots in stems of wheat previously cited, also mentioned the presence of nine eggs with the maggot. Without a doubt these were the mites that had attacked the maggot, though this was long before the mite was known to inhabit this country, it being a native of Europe, as far as now known. _ THE LESSER WHEAT STEM-MAGGOT. ( Oscinis carbonaria Loew. Fig. 15, d.) With our present knowledge of the early stages of development it is yet impossible for me to separate out from several other allied species such as belong to this one and give a detailed account of its life cycle, and especially is this true with reference to Oscinis soror, or what is the same thing, Oscinis variabilis Loew. To be able to do this will require the most careful and exact studies of the early stages 52 of the offspring of adult flies belonging to each species ovipositing on plants known of a certainty to be free from infestation by other species. Such studies can only be carried out with the aid of better conveniences than I have had at my disposal, and should be taken up by the General Government, whose investigators are not restricted by State lines, and who can follow wherever their problems may lead them. Though Oscinis soror (O. variabilis) has been reared from growing wheat by others as well as myself, I have found that O. carbonaria has been thus obtained with the greatest frequency over the widest range and under conditions that lead to the belief that it is the more important of the two, from an economic point of view at least. LIFE HISTORY. This can only be given in a general way, as in no instance has the progeny of a single female been carried through the life cycle and the several broods throughout the year clearly defined. I have myself reared this species from growing wheat in Illinois, Indiana, and Ohio, over not to exceed two degrees of lat- itude, or collected them in the wheat fields throughout this area, or they have been ' 2” reared in Washington in the a a Department insectary from Fic. 15.—Oscinis soror Macq.; a, mature fly: b, antenna plants sent there by me from of same; Ge puparium; d, head of O. carbonaria—a, ¢, d, this same territory, as fol- magnified; b, still more enlarged (original). Pnze Urbana, ll. J uly, August, and September; Oxford, Ind., from May to October, not inclu- sive; Lafayette, Ind., July, August, and September; Wooster, Ohio, May, June, July, August, and September; and in the latter locality from August-sown wheat. In the insectary I have also reared it in November, December, and the following April, but did not observe it abroad in that locality during November, December, or April. Besides these rearings of mine, it was reared at Washington, July 7, from plants received on the 3d of same month from Prof. Lawrence Bruner, West Point, Nebr., and reared by Forbes, in Illinois, September 17, from volunteer wheat. This is the species mentioned by Doctor Fletcher as being so destructive in the Dominion of Canada in 1890, as shown by specimens of the adult which he has kindly sent me. “ There was a bad outbreak of this insect in a field of wheat near Wooster, Ohio, in the fall of 1891, and the field was badly affected. In March of the following year I found many larve and pupe about the bases of the affected plants, and an attempt was made to study «See Experimental Farm Reports, 1890, p. 158, and 1898, p. 177. 53 them further, but insuflicient facilities for doing so prevented. There was, however, plenty of evidence that the insect may winter in either the larval or pupal stages. A single specimen was reared at the Department in Washington from a stalk of wheat received from Mr. J. G. Kingsbury, editor of the Indiana Farmer, the fly appearing June 18. In this case the maggot was in the straw above the upper joint, and the wheat head was evidently killed by its attack. From all of these facts it seems that its life cycle may be about as follows: It may winter over in the field either in the larval or pupal stage, the adults emerging in May. From the presence of larve in the stems of wheat and grass from which adults have afterwards been reared it would appear that there is a brood of flies emerging in June and July, much as in Meromyza americana, which lay their eggs in grass and volunteer grain; another brood of flies resulting in September and October whose offspring hibernate as previously stated, there being, as in Meromyza, three broods each year, from six weeks to two months being required for the insect to pass through its development during the summer months. FOOD PLANTS. 1 have reared these flies only from wheat, probably because I have made no special effort to rear them from any other plant. Doctor Fletcher has reared the species from Agropyron caninum, A. tenerum, A. repens, Pou pratensis, and Llymus canadensis.“ PLACE AND METHOD OF OVIPOSITION. I haye observed oviposition only among small wheat plants, but presume that the methods employed in such cases do not differ from those where the food plant is some of the grasses. The object on the part of the female seems to be to place her eggs low down on the plant, as near the root as possible and along the enveloping edge of the sheath. The very young larve are always to be found in this situa- tion, and the edges of the enveloping bases of the leaves are always ragged and discolored in infested plants. NATURE OF THE INJURY. The young maggot on hatching from the egg feeds along the thin edge of the lower base of the enfolding leaf where it is white, juicy, and tender. It seems to make no effort at first to reach the central portion of the plant, seeming to know that that part will remain ten- der and succulent, but gradually works its way inward and upward to a point just below where the central spindle-shaped unfolding leaf leaves the ensheathing portion of the next older one, the exact locality seeming to be decided upon according to the toughness of this central «Experimental Farms Reports, 1890, p. 158. 54 leaf, which of course varies with age and may be the first slender shoot of the plant, or one of the older and tougher tillers of much older plants. This central compactly rolled leaf is cut off, the maggot at first working upward until this leaf becomes too tough or begins to wither, when it reverses its position and works downward, where the food supply is always fresh and juicy. Pupation does not take place here, but the larva makes its way when full fed to between the bases of the older leaves, and in that situation the puparia are to be found. A very young plant does not admit of very extended travel by the larva, and in an older one the continuity of its path is soon obliterated by the growth of the plant itself, and the larva is frequently found a couple of inches above the base where it entered after hatching from the egg, as is witnessed by the minute patches eaten out of the leaf. As but a single maggot is found in each stem, I have often wondered if the female so distributed her eggs as to prevent a clashing of young, and feel very much inclined to the opinion expressed in some unpub- lished notes by Mr. Pergande to the effect that more than one egg may be deposited about a single stem, but the oldest and strongest maggot kills off the weaker, leaving but one in full possession. EXTENT OF RAVAGKES. Usually the work of this species is so confused with that of others as to render anything like a definite estimate of the damage that can be justly charged to its attacks in the grain fields almost impossible. I have never observed injuries to the full-grown straw, though I have occasionally found larve in them that I presumed to belong to this species. In fall wheat the plant recovers from a slight injury, espe- cially if growing in a fertile soil, and I apprehend that more damage will follow an attack in fields where the soil is poor or badly worn than where it is richer. In the field of wheat near Wooster, Ohio, that was so severely injured in 1891, the Hessian fly was also present and did fully as much injury as this insect, both I should say, destroy- ing fully one-half the crop. Dr. Fletcher has called attention to a field of spring wheat in Canada that was damaged fully 75 per cent, for the most part due to the attacks of this species. In the United States, I do not believe that an injury of from 5 to 15 per cent of the crop by reason of the attacks of this and other Oscinis is at all unusual, but this can not in all cases be wholly charged up to this particular species. DESCRIPTION. The following description of the fly of Oscines carbonara has been kindly drawn up for me by Mr. Coquillet: A small, black, two-winged fly having the knobs of the halteres, the feet, and usually both ends of the tibise yellow. Length varying from 1 to nearly 2 milli- 55 meters (from one twenty-fifth to nearly one-twelfth of an inch). The last joint of the antennez is nearly circular in outline, and on the upper edge is a nearly bare bristle or arista; on the upper part of the otherwise opaque head is a polished, nearly triangular spot that extends from the extreme vertex almost to the antenne. The wings are nearly transparent and are without an auxiliary vein—that is, there are only three (instead of four) veins that terminate in the front edge of the wing before its apex; the vein bordering the front edge of the wing extends beyond the extreme apex of the wing; the usual two small cells near the base of the wing are wanting, the anterior one being confluent with the discal or central cell, while the posterior one is wanting, there being only one cell (the axillary) behind the fifth vein. The legs are devoid of bristles and of stout, apical spurs, and are rather short and robust; the first joint of the feet is rather slender and longer than any of the other joints. The thorax is also without bristles, except along the sides and across the posterior end; it is somewhat polished and is devoid of gray dust. The face does not project strongly forward on its lower part; the proboscis is short, robust, and terminates in the fleshy lips. CLOSE RESEMBLANCE TO OSCINIS SOROR MACQ. Oscinis soror Macq. is very closely related, but may be distinguished by the fact that the polished spot on the upper part of the head extends only about halfway from the vertex to the antenne, instead of almost reaching the antenne, as in the preceding species. (D. W. Coquillett. ) At present, owing to the confusion of this species with soror, an account of which will follow, it seems impossible to give desirable descriptions of the preparatory stages of this insect. I have followed those of Professor Garman, not knowing whether he was dealing with this species or not, but because his descriptions seem to me to apply as well to this as any that I could supply. It must be kept in mind, however, that this is only a temporary makeshift to give some kind of an idea of what these look like, and thus enable the farmer to reduce the uncertainty as to the identical species that is injuring his crop, and that later and more careful investigations will probably show that this and several other species, but with habits that are practically the same, have been confused, and thus the present arrangement serve a practical if not a scientific purpose. Egg.—The egg of what is supposed to be this species was described by Mr. Per- gande in the Department notes as follows: Colorless, polished, and longitudinally ribbed with numerous extremely fine transverse strize. Larva.—Cylindrical, white, with faint yellow cast. Body composed of thirteen segments. No head and no legs. Mouth with two strong black hooks. Posterior segment of body with a pair of knob-like prominences. Length of alcoholic speci- mens, 0.14 inch. Pupa.—tIn this stage the insect is inclosed in the hardened and brown skin of the larva and this is called the puparium. This last is bright yellowish-brown, with distinct and very finely wrinkled divisions. The two knob-like prominences in the larva are retained and are conspicuous at one extremity. The black hooks of the larva are molted with the skin and can be seen through the puparium. The obso- lete mouth of the larva is withdrawn, blackened, and wrinkled. Length from 0.10 to 0.14 inch. 56 PREVENTIVE MEASURES. It is doubtful if one farmer out of a thousand fully realizes the danger arising from volunteer wheat. This growth springs up in the fields in greater or less abundance, and is almost invariably left to itself, as, having no value, it is thought not worth while to bother with it. Besides, the general practice in many sections of the coun- try of seeding the wheat lands to timothy and clover would prevent any attempt to destroy the volunteer wheat, except by pasturing, which is not considered a part of good husbandry at that season. A rotation of crop, however, has in itself some advantages, as it forces the flies to migrate from one field to another, in which there must be more or less casualties, and many more would probably be attracted to the grasses and the young fall wheat be protected to this extent from attack. Where wheat is to follow wheat in the same field, 1t will certainly pay the farmer to destroy this volunteer growth, as it not only harbors all of these flies and offers unusual advantages for the development of this midsummer brood, but it offers a breeding place for the Hessian fly as well. Volunteer wheat, then, should be destroyed wherever possible by the plow or disk harrow, and, where practicable, by pasturing, so as to prevent the flies from breeding therein. Burning over the grass lands, except timothy or clover, where it is probably not necessary, will offer much protection, espe- cially in spring-wheat growing regions, and where fall wheat is much grown, reasonably late sowing will probably prove one of the most effective means of protection. NATURAL ENEMIES. While this species probably has its usual number of natural ene- mies, it is not always possible to determine the exact species from which these have been reared, but an insect that is parasitic on one species of these flies might be confidently looked for as being parasitic upon other allied species. /yssalus oscinidis Ashm. is parasitic on a species of Oscinis larvee mining in the Jeaves of plantain, in Wash- ington, D.C. Aphereta californica Ashm. and A. oscinidis Ashm. have both been reared from other species of Oscinis, while I have reared Cyrtogaster occidentalis Ashm. from either this species, O. soror, or O. wmbrosa, in Indiana, though it is known to occur from Texas to South Dakota and east to Virginia and the District of Colum- bia. These are all minute four-winged flies, and there are probably many others that also help to keep these flies reduced in numbers. I have also observed the common parasitic fungus Entomophthora musce attacking the flies, but this is probably a minor factor among their natural enemies. 57 THE AMERICAN FRIT-FLY. (Oscinis soror Macq. Fig. 15, p. 52.) This species has been so interminably confused with other allied species, especially with what has been going the rounds as Osc7/n/s varabilis Loew? «a synonym, and as frequently confused with O. car- bonaria as with this, that it seems almost impossible to say anything about it with any degree of certainty that one is not really dealing with something else. Oscinds soror is, nevertheless, a valid species, and its larve in all probability attack growing grain, though I have myself rarely reared it from grain, teal my proof of its destructiy e- ness in wheat fields is unfortunately not as conclusive as I wish it were. The larvee certainly have a wide range of food plants, as I have reared it from maggots in the stems of Panicum er us-galli in Indiana during September, and also from the stems of Poa pratensis in June and from wheat in July. It has also been reared from larve wintering in the seed capsules of Vernonia noveboracensis May 15 in Washington, D. C.; in June and July, at Columbus, Ohio, from oat plants; from the roots of cucumber, October 2, in Maryland; and from strawberry plants in Michigan. Last year I reared the flies from the stems of /vagrostis minor at Urbana, Ill., in September. These definitely authenticated rearings of the flies show a wide range of food plants, and the species is one of the most abundant of all the Oscinids. CONFUSION WITH OTHER SPECIES. Owing to a species having been found in Illinois and Kentucky attacking wheat and doubtfully determined by Doctor Williston as Oscinis variabilis Loew, now known to be a synonym of this species, and this determination having been applied elsewhere to other Oscinide attacking wheat, has led to much confusion, as where the name 0. va7?- abilis has been applied to a form committing depredations, we can not say with any degree of certainty whether the insect involved was this species or 0. Seve unless specimens actually reared from the plants so-attacked are at hand. Realizing the difficulty when I began the preparation of this bulletin, I applied to Mr. Coquillett, of the United States National Museum, for suggestions as how to best over- come it and received from him an offer to determine any material reared from larve attacking wheat in various parts of the country. Doctor Fletcher had published accounts of the ravages of Osc7¢nis vari- abilis Loew? in Canada, Dr. Otto Lugger of similar ravages of Oscinis soror in Minnesota, and Professor Garman of the attacks of Osc7n7s variabilis Loew? in Kentucky. Application was therefore made to Doctor Fletcher, Professor Washburn, successor t6 the late Doctor Lugger in Minnesota, and Professor Garman, for reared material in order to as far as possible place the responsibility for these depredations 58 on the species actually engaged therein. Material kindly placed at my disposal by Doctor Fletcher has shown that it was Oscinis carbonaria Loew that committed the depredations inCanada. Professor Washburn was less fortunate, though he did all that was possible for him to do to aid me, and sent specimens that, judging from the labels attached, had been reared by Doctor Lugger, but whether from wheat or not it is impossible to determine, as nothing could be found that would throw any light upon this point. The specimens sent me from Minnesota by Professor Washburn comprised two species, QO. soror and O. dorsata Loew, the former having been supposed by Doctor Lugger to have been responsible for the injuries to wheat in Minnesota in 1892, while the latter was reared by me from wheat plants in Ohio in the fall of 1897, thus indicating that both might have been involved in the Minnesota trouble. Assuming that Doctor Lugger had sufficient grounds for holding Osecznis soror responsible for the damage in his State at the time stated, I have so considered it here, but have thought proper to indicate the uncertainties surrounding this conclusion. Not being able to secure any material whatever from Professor Garman, I am forced to reluctantly place the blame for the outbreak in the wheat fields in Kentucky in 1889 upon Ose7n7s soror, but with a strong suspicion that it was really Oscinés carbonaria that was responsible for the trouble. I have applied Doctor Lugger’s descriptions of the larva and pupa to this species as being the best that can be done with our present knowl- edge of these insects, but subject to revision, as future investigations shall clear up more or less of the obscurity at present surrounding them. DEPREDATIONS IN MINNESOTA. There is one fact connected with the Oscinis problem in Minnesota that seems to point especially to (Y. sovor as the real depredator, and not V. dorsata, and that is in the striking difference in the color of the two, the former being black and the latter yellow, a difference that could hardly have escaped the keen eyes of Doctor Lugger, and I can not but feel that he was correct in his attributing the depredations to the species now being considered. I strongly suspect that some of the ‘‘deadheads” to which Doctor Fletcher has called attention in his reports and other publications as occurring in the wheat fields of Mani- toba and the Northwest Territories may have been to some extent due to the work of this species also. Doctor Lugger seems not to have studied the several generations of the species in his State (Minnesota), but gave his attention especially to the one that proved the most destructive. From what has been stated of the insect farther to the southward, it would appear that there are the same number of broods as with O. carbonaria, the pest wintering over in the young plants of fall wheat and grass. In Min- nesota it evidently winters in the straw, from which it would seem 59 that in the north there 1s one less brood than there is farther to the south, a condition of affairs entirely possible, as we now know that the Hessian fly is there largely at least single brooded, but double brooded farther south. In his second annual report as State ento- mologist, pages 6 to 10, Doctor Lugger gives these facts relative to the work of the insect in his State: During the summer and early part of the fall numerous letters were received from many parts of the State in which the writers complained about minute worms which infested the stems of wheat just above a joint from 3 to 4 inches above the ground. The specimens received at the same time showed that, as a general rule, the first and second joints of the plant were infested. Some farmers complained that their crop of wheat was thus very materially reduced. The plants harboring the worms did not indicate their presence until flowering time, but as soon as the head began to form the stem above the injured joint wilted, turned yellowish, and soon broke down entirely by bending over the infested spot. * * * But when the infested stems were investigated it was found that the worm had weakened them to such an extent that when the head was formed the plant became topheavy and broke down at the weakest point from force of gravity. * * * These heads were either entirely empty or filled with berries more or less shrunken. The bent or partly broken stems were, as a general rule, still adhering to the lower portion of the plant. This bending or breaking had taken place most frequently above a node or joint about 3 inches from the ground. Just below this breakage, and immediately above the joint, the culprits were to be found. In most cases but one puparium, but in a few cases two, three, or even more puparia could be detected. Such a puparium is the contracted and hardened skin of the larva or worm; it is of a glossy, chestnut- brown color, shading to yellowish brown toward the smaller end. If closely inspected it shows faint traces of sutures or segments. * * * These seed-like objects contain at this time (October) whitish larvze or worms, and no pup have been detected inside of them up to this date. * * * Judging from the fact that only pupe [puparia?—F. M. W.] can be found at this time, it would appear as if this insect hibernates in that stage. This is really the only one in which it could well pass our northern winters, being in that stage well protected by its old and thickened skin and by the stem of the plant. The puparia are inserted in the mate- rial of the upper part of the node, inaccessible to any moisture from the outside, as the stem above does not break off entirely, but simply bends in a more or less acute angle a short distance over them, thus preventing the entrance of water. Yet the culm is sufficiently fractured to permit a free exit of the future flyinspring. * * * The damage caused by this insect in 1892 was by no means small. In many places fully one-fourth of the entire crop of wheat was destroyed, and in a great many more the losses amounted to at least one-tenth. As many places are badly infested, the total amount is quite large, and if no steps are taken to prevent it a repetition may become ruinous in 1893. Most farmers plowed their fields in the fall of 1892 or early in 1893, and consequently the losses in the latter year were small, and in 1894 but very few of these insects were to be found. The spring of this year [1896?—F. M. W.] being very wet, prevented extensive plowing, and the insects, not being disturbed or plowed under, again became a pest and caused considerable damage. The name “‘frit-fly’’ is a well-deserved one, as Swedish farmers call the worthless grain resulting from the attack of such flies ‘‘frits.”’ LIFE HISTORY. As stated by Doctor Lugger, the life history is still very obscure, and it will require careful study and close observation to secure a knowledge 60 of it over the country. The facts given by him in his report are unlike what has been observed farther south, but these differences are not sufficient to indicate that it was not this species that caused the injuries mentioned. Even if we assume that the insect reared in Kentucky by Professor Garman belonged to this species, we find that adult flies have been reared by others in May, late June, and early July, and again in September, thereby indicating three broods in the vicinity of latitude 40°, the species wintering as larve or pup, probably the latter, the flies emerging from these ovipositing in May, the adults from these appearing in June and July, these in turn giving origin to a fall brood in September, whose progeny winter over as stated. In more northern and inland sections of the country it seems that the fall brood may drop out and the one occurring farther south in midsummer pass the winter as puparia and the adults emerge the following spring. FOOD PLANTS. Either this has a greater range of food plants than Oscinis carbo- naria, or else we have not learned much about those of the latter. As it is, the food of this species is so varied as to almost incline one to the suspicion that it stands accused of ravages that should be placed to the credit of another but for the facts supplied by Doctor Lugger. However, this variation in its bill of fare gives the farmer a still better opportunity of fighting it outside his grain fields. DIFFICULTIES IN STUDYING HABITS. The fact that maggots taken from wheat plants in a field develop these flies does not necessarily prove that other maggots attacking wheat in the same field will produce the same species of flies; there- fore, descriptions drawn up from such collections may or may not be correct, and for the same reasons observations on the habits of such larve are liable to be incorrect. It is only by placing flies on plants known to be free from all other infestation and studying these that we shall be able to get at the truth in relation to anatomical and biological facts. An investigator will then know just which species he is dealing with, and whatever descriptions are drawn up from material secured in this manner and whatever observations are made upon them will be sure to be accurate so far as the species under observation is concerned. In no case has this been done, and as a consequence we have only a general knowledge of these insects, and any descriptions of the larve may or may not prove correct in future. Though there isa noticeable difference between the adult figured by Doctor Lugger as this species and the one figured by Professor Garman as Osc/nis variabilis Loew % the figures of the larva and puparia are exceedingly alike. For the same reason any recommendations looking to the control of the pest 61 in the grain fields must be made somewhat at random and aimed at Oscinide in general rather than at this particular species. REMEDIAL AND PREVENTIVE MEASURES. Over the area where winter wheat is cultivated the same measures that have been urged against the two wheat stem-maggots will apply equally well here, so far as we now understand the habits of this species. These are the destruction of volunteer wheat, the burning over of waste grass lands in winter and early spring, and late sowing of the grain in fall. In spring-wheat regions the experience of Doctor Lugger in Minnesota is strongly indicative of the effect of plowing the infested fields as soon as possible after the crop has been removed. He states that in the fall of 1891 and spring of 1892 not more than one-half of the acreage of wheat land was plowed, owing to unusually wet weather during these periods, and the pest that had gained a foot- hold, as it were, in 1891, meeting with no reverses on account of lack of plowing, simply continuing to increase in numbers, with the result that in 1892 it committed serious and widespread depredations. Where the fields can be burned over in fall or spring the result will, of course, be the extermination of the pest in such fields in the northern portions of the country, but farther south it is the grass lands that need to be burned over, since there is no way of reaching the insect hibernating in the winter-wheat plants. The fields of spring wheat in the North will, of course, be to some extent also protected by the burning over of the grass lands in fall or spring. DESCRIPTION. The difference between this species and Oscinis carbonaria have already been pointed out in the treatment of the latter species (see p. 55). Larva.—This very closely resembles that of O. carbonaria, as is shown by the illustrations used by Doctor Lugger in his publications. He states, however, that the larva is of a greenish-white color when alive and just removed from the culm. Puparium.—Here, again, it would be difficult to identify the pupa- rium by either the illustration or description given by Doctor Lugger, as both closely resemble those given of O. variabilis? by Professor Garman. Doctor Lugger describes this as being of a glossy chestnut- brown color, shading to yellowish brown toward the smaller end, and showing faint traces of sutures or segments. Of the other species of small Oscinidz whose larve are found in and about the stems of growing grain I have already written, and it is impossible with our present knowledge of them to go into further details. Some of these may be destructive and some may not, as the fact of these having been reared from grain plants does not necessarily 62 prove that they are destructive, as they may live upon the dead and decaying older leaves or they may simply inhabit the burrows made by other insects. The practical farmer will probably be able to meet their depredations by the same measures that have been recommended for those species with which we are the most familiar, at least until a more extended study can be made and more light thrown on their habits. CONCLUSION. In the foregoing it has been the aim of the writer to so present this subject as to enable the farmer to distinguish some of the more obscure enemies of his crops and prevent a peculiar and subtle shrinkage in the profits of his labors, and one that he can meet in most cases by simple measures that cost nothing except the time consumed in carry- ing them out during seasons or days of comparative inactivity on the farm. Not all of the ravages in the wheat fields are due to the Hessian fly, and, indeed, the crop reports are usually wholly unreliable in respect to the actual occurrence of this insect, except it be in cases of over- whelming numbers. One of the most practical preventive measures that can be applied against the Hessian fly will also prove of value in warring against these other pests, viz, late seeding of fall wheat in autumn; and asecond measure, that of rotation of crops, will be found almost as valuable. Fighting insects demands a better system of farming, which of itself will pay in other directions, and the American farmer must calculate upon insect depredations as no small element in his business. Of what use is it to rear two blades of grass where but one grew before if he is to lose both of them by reason of insect attack ¢ It is not the farm but the profits thereof that are lost through the devastations caused by injurious insects, and it costs the American farmer more to feed these insidious foes than it does to educate his children. Nhs ; aire r ao PAL ST HNEES OF TH SUGAR HET BY F. H. OHITTENDEN. NTOMOLOGIST IN CHARGE OF BREEDING EXPERIMENTS. sees! , TS. \) |. WASHINGTON: ge aaa (GOVERNMENT PRINTING OFFICH, 3) f Wek Mie i FOS. =) j ‘ 4 \ > : oy ( 4 4, ~ 5 - - \a " r v f ry + ? ’ iA 4 (oy CSUN EN WOT yt AoW rans BU AN < PEL } Ke CAT ne Hh een Mee Ns ONG: rib ; BA, ; Wes, DEPSK IMENT: OR AGRICULTURE. DIVISION OF ENTOMOLOGY—BULLETIN No. 43, L. O. HOWARD, Entomologist. a bao ACCOUNT OF THE PRINCIPAL INSEUT ENEMIES (OF THE SUGAR BEET. BY eS CERT PEN DEIN, ENTOMOLOGIST IN CHARGE OF BreepING EXPERIMENTS. AN WASHINGTON: GOVERNMENT PRINTING OFFICE. a is a DIVISION OF ENTOMOLOGY. L. O. Howarp, Entomologist. C. L. Maruatt, in charge of experimental field work. F. H. Carrrenven, in charge of breeding experiments. A. D. Hopxins, in charge of forest insect investigations. Frank Benton, in charge of apiculture. W. D. Hunter, in charge of cotton-boll weevil investigations. D. W. Coquittetr, TH. PERGANDE, NATHAN Banks, Assistant Entomologists. E. A. Scuwarz, E. 8. G. Titus, Investigators. Miss H. A. Ketiy, Special agent in silk investigations. k. S. Currron, F. C. Prarr, Aueust Buscx, Otro Herpemann, A. N. CaupbeELt, J. Korinsxy, H. G. Barper, Assistants. W. E. Hinps, A. L. Quarntance, W. F. Fiskr, G. H. Harris, H. E. Burxs, A. N. Morri1u, Temporary field agents. 2 LETTER OF TRANSMITTAL. Unirep States DePpaRTMENT OF AGRICULTURE, Division oF ENTOMOLOGY, Washington, D. C., November 3, 1903. Str: I have the honor to transmit herewith for publication A Brief Account of the Principal Insect Enemies of the Sugar Beet, prepared by Mr. F. H. Chittenden, of this office. This paper has already appeared as a portion of Report No. 74 of the U. 5. Department of Agriculture entitled ‘‘Progress of the Beet-Sugar Industry in the United States in 1902,” for which it was specially prepared by your instructions. Owing to the subordinate position held by this article, the consideration of the subject was limited to the more prominent msect pests affecting sugar beet, and it was therefore impossible to enter into detail regarding these or other less injurious insects which are known to affect this important crop plant. Many of the species, especially those of greatest economic importance, have received more extended notice in other publications of this office, notably in Bulletins Nos. 19, 23, 29, 33, and 40, of the same series, and there are many others known to affect sugar beet which are not even mentioned, chiefly because we are not sufficiently conversant with their economic status. I recommend the publication of this paper as Bulletin "No. 43, of this Division. Respectfully, . L. O. Howarp, “ntomologist. Hon. James WItson, Secretary of Agriculture. - 7, a dS & Me - flor. eA rrr i: MI ies ee es! : is . oO Pees ie = * | ares Ii aes ey ee NPS: me MIACREICE OT Neer pene ee ete ange ee ie Se me EG Ea ee SL Oe eee Met econ aml Ned-Dee les sor f io. . aces Sees qee fae ace coe e See mcc esas ete icch anc spinach Carrion bectles = .2. 522.62... Gecn ssc haces Sek cece LE NERA OYSS HES 2 es ho i A a A Sp 9 Se JNIngiy TROLS A jose s Soca de SSE OS Ce eee ee eae ye ES GREMIIE Lege Shc lS ae eee ee a ee gi eee ieee ne eee Fe Serene M CUMUIBE SS pe on oe eee tcc ten lene coke cane caateses Srassheppers, crickets, and related insects -..........s.2..--. 2.2.22 256-2. sae Ce er eee nan ee meee ae Bona es eee owe ene meee See eee er earns Soe ee ms cise Base sues Coeds bet sb a Soa ame AE eer Ore ae) eke eeta woes eouee eae som ae eee eee e as aE ee re eye, Ce Sk Se oe Sem weno oneal wen bee es EE Ey UNDE CSTE ILS TS] 0) 272 Fo Re a a ne Rn (EDP DENS LL ai ey le ae Ne Ue ge Mean Ae pal ey net oe ee et fe ce oF Whe co “I o> we) ILEUSTRATIONS: = Monon punchicollis: beetle, eggs, and larva... _-~-..-22..--s--6--- PE MOMOTIO: DURGICOIIS: VATIOLY,, «(22022 =. Smee a yan ere eae sco pee ae MENON TUE CORSULI BERLIOS oat cnt sets oa. tonto nc basses Meas Diabrotica 12-punctata: beetle, egg, larva, and pupa-..-------.------ Cains Uriined. DEEL ang lanvyae of. 050 8 2S ws owners ca Osa OMICS PECHIO N= Mace ita ee ts oak eae ae as cee ae dices . Disonycha xanthomelxna: beetle, egg, larva, and pupa..--.---------- . Systena blanda: beetle, larva, and eggs. .-.- Se ae aie ae re ee Este nena aaricdonm, Of Wectle 252.7. cc5..2-.ee-s es - --saeee 10. Is: 12. ies 14. 15. 16. Ly. 18. 19: ISU SEETLOM OTLUELE Ss DEC] Crier Biya sis ay et cie eer aia a Siete ee pele eee SUD CE WISI a DE CLICS 22 28 eau acinana taces nema ies eee ee ee SLO LOR OTE OCTOSO RCE ULC pari mints irs er otra ian eee tle ts pele Epicauta vittata: beetle, eggs, and larval stages ...-.-.-.------------ LRU UTP SETHTS VISE Se oe eae eo OSES COU OHS So aiGe se ZENER ATID ECCT EDD) OMG 02018 ie na LEO R ORION UO TEAC CTOIS 4 O10) OF ele Ae Ae ee Ce One ee eee ee AE DOCU AREETC RCL MOC CLL Campin Sete eines Meee. ee ee eine ae cee ee LER SQTOTITE TRON COUCHES Oe a ee oe eae oe nO ee eee IE CAULGMDANITSY LOCI COLMOC CHIC = te nen | Nine (es eee aes eeiee see cee i) Cs COS INN ENS) END mH Ooo wm aI Go Go G CO OU Hm GC bo GS coos] He He iS He He He He “IO Ot He ILLUSTRATIONS. . Macrobasis unicolor: beetle .........----- . Macrobasis albida: beetle -.....-.-.----- %antharis nuttalli: beetle...........----- Loxostege similalis: moth, larva, and pupa Mamestra picta: moth, larva, and pupa -- Tsia isabella: moth and caterpillar ’....--- ee . _"vicerus imbricatus: beetle, eggs, and larva........-...------------ . Epicerus imbricatus: beetle attacked by fungus..........---.------- . Peridroma margaritosa: moth, eggs, and larva.......-.------------- . Agrotis ypsilon: moth and larva ...------ . Noctua c-nigrum: moth and larva....-.-- . Chorizagrotis agrestis: moth and larva... . Prodenia ornithogalli: male and female moths --.-.-.----.-------------- . Prodenia ornithogalli: pale and dark forms of larva ...-------------- . Euphrocera claripennis: fly, antenna, and puparium...-..-..--------- . Caradrina exigua: moth, egg, and larva... . Caradrina exigua: enlarged section of larva ...-.--. ..-<.-s.s2--5066 . Loxostege sticticalis: moth and larva...-..-- . Agathis vulgaris: parasitic enemy of sugar-beet web-worm.......---- 36. . Limneria eurycreontis: parasitic enemy of garden web-worm --------- . Deilephila lineata: moth, larva, and pupa- 39. . Mamestra picta: larval stages ......------ . Leucarctia acrea: moth and larya..--.---- 42. . Melanoplus femur-rubrum: adult ..-..----- . Melanoplus spretus: females laying eggs. - - . Melanoplus spretus: nymphs .-.-.---------- . Melanoplus differentialis: adult ..-.-------- . Melanoplus bivittatus: adult ......-------- 48. A simple coal-tar pan to be drawn by hand ............-.---------- . A canvas hopperdozer to be drawn by horse .....------------------ . Pegomya vicina: fly, egg, maggot, and puparium......-...---------. 51. Lygus pratensis: adult and last nymph stage..-...-..-.--..---------- 52. Lygus pratensis: nymph stages -..------- . Nysius angustatus: adult, nymph, and punctured leaf ...-...-------- . Halticus uhleri: male and female bugs --- . Empoasca flavescens: adult ......-----.-- . Head of plant-louse showing sucking beak. .-.......--.------------ . Aphis gossypii: adult females and nymphs . Hippodamia convergens: adult, pupa, and larva ......--------------- . Lachnosterna arcuata: beetle, pupa, larva, ; Lagyrns gibbosis: pectle.\-. - -22-2222-= . Agriotes mancus: beetle and larva.......- . Monocrepidius vespertinus: beetle, larva, and pupa ..---.------------ . Dactylopius citri: adult female....-.-..-- . Pegomya fusciceps: male and female fly, larva, and pupa ---.----.--- . Tetranychus bimaculatus: adult and details alld ee. 25228 See A BRIEF ACCOUNT OF THE PRINCIPAL INSECT | ENEMIES OF THE SUGAR BEET. INTRODUCTORY. Recent estimates made in the Department of Agriculture show that the world’s production of sugar in 1902 amounted to nearly 10,000,000 tons, of which nearly 6,000,000 tons were manufactured from sugar beets.“ The increase in the production of sugar from beets as com- pared with the production from cane has for many years been rapid and continuous. The first attempt to manufacture beet sugar in the United States was made in 1830. After numerous failures a successful factory was established in California about twenty-five years ago. In 1891 only three beet-sugar factories were in operation in the United States; but by 1902 the number had increased to 42, with many more in prospect. The manufacture of enough sugar to supply our home demand would require the operation of about 400 factories, or as many as there are in Germany, the principal sugar-beet growing country of the world. This in turn would require the cultivation of a very large acreage in sugar beets. More than $50,000,000 is reported to be invested in the beet-sugar industry in this country, and there is promise that the industry may, before a great many years, develop to the extent above indicated. Hence, any information which may be of use to sugar-beet growers is of immediate interest and practical value. Although the beet-sugar industry is still in its infancy in America, already many insects—150 species in round numbers’—have been found to use beets as food, and, while comparatively few occasion losses of consequence, with the coming of years and the increase of cultivation of the sugar beet, other insects will acquire the habit of feeding upon it, and more extensive injuries may be expected each successive season. If we leave out such forms of insects as blister beetles, army worms and cutworms, flea-beetles, leaf-beetles, and some few others, we may say that beets at the present time suffer comparatively little damage through insect ravages. The recent extension, however, of sugar-beet culture in this country has been the means of bringing to notice, through the publications of the Department of Agriculture and several of the State experiment stations,’ a large number of insects not previously identified with attack on that plant. A very considerable proportion of the insect enemies of sugar beet which are practically identical with those which affect table beet and «Charles F. Saylor, Rept. No. 74, U. 8S. Dept. Agr., p. 124. .» Forbes & Hart, Bul. 60, Univ. Ill. Agl. Expt. Sta., 1900, pp. 397-532. ¢See Bruner, Bul. 23 [old ser.], Div. Ent., U. 8. Dept. Agriculture, 1891, pp. 11- 18; Osborn & Gossard, Bul. 15, Iowa Agl. Expt. Sta., 1891, pp. 265-272; also numer- od ous shorter articles. 7 8 spinach, subsist normally on wild plants of the same botanical order— the Chenopodiacez, or goosefoot family, which includes our common lambsquarters (Chenopodium album), spinach, and some related plants that are cultivated for ornament and as forage crops. Of the latter are several forms of saltbush (Atriplex). Many beet depredators also live on plants belonging to an allied family—the Amaranths—which contains many common weeds, including pigweed, as well as a few ornamental forms. | One of the earliest instances of injury to the beet reported in America is that furnished by our first economic entomologist, Harris,@ in1841. In quitewecent years, however, several species have been so prominent as pests in fields of sugar beet that they have received names indicative of their beet-feeding habit, while a few take their common names from spinach. Among these are the beet army worm,’ the beet webworm,’ the beet or spinach leaf-miner,? spinach flea- beetle,’ beet carrion beetle,” beet aphis,” European beet tortoise beetle,” and two species of leaf-beetles.‘ Of the various insects known to live on this plant, not more than about one-third, or 40 or 50 species, can be classed as noticeably destructive to it. It is difficult to decide at this time, owing to the lack of study given the subject over the entire country where beets are raised, which forms of insects are of the highest importance. The different insects which have been mentioned specifically are more attached to beet and spinach than to other plants, and the greatest losses, if we take the entire country into consideration, are probably due to the ravages of flea- beetles, but they, as well as cutworms and similar groups, are so periodical or, more properly speaking, irregular in their depredations that an exact estimate of their economic status can not be made. Differ- ent species of leaf-beetles and caterpillars other than cutworms do more or less injury, and several blister beetles devour the foliage of sugar and table beets freely; most forms of the last, however, usually make their appearance so late in the season that, although defoliation may be excessive, comparatively little damage is accomplished. The same is true of some species of grasshoppers. Beets until recently were comparatively free from subterranean insect enemies, but there are two forms of common farm pests, white grubs and wireworms, that affect underground portions of the plants and occasionally injure them; in addition to these, some kinds of root- lice and mealy-bugs injure the roots by suction, rendering them small «The species mentioned is the zebra caterpillar (Mamestra picta). Rept. Ins. Mass. Inj. to Veg., p. 328. > Caradrina exigua. S Silpha opaca. ¢ Loxostege sticticalis. 9 Pemphigus betx. a Pegomya vicina. h Cassida nebulosa. € Disonycha xanthomelena. ¢ Monoxia puncticollis and M. consputa. 9 and soft or spongy when they do not kill them outright. Some other sucking insects—plant-lice, plant-bugs, leaf-hoppers, and the like— occasionally injure the plants by absorbing their vital juices, but with some notable exceptions they are comparatively unimportant as beet pests. Many of the most destructive or best known sugar-beet pests have received more extended notice in recent publications of the Division of Entomology, notably in Bulletins 19, 23, 29, 33, and 40, new series (from which the present article has been largely collated), in addition to other publications which have been cited in the introductory paragraph and others which will be mentioned in connection with the different species as they are considered. In indicating methods of control to be observed for insects which are not special enemies of the sugar beet, it has been found necessary, owing to our somewhat imperfect acquaintance with all of the condi- tions which surround attack, to treat the subject in a general manner. The remedies for different forms and classes of insects are therefore considered as they occur upon the farm. Where deemed advisable, however, an effort has been made to limit remedial directions to the occurrence of many of these insects in fields of sugar beet. It may therefore be stated that as a general rule remedies prescribed for insects as-these occur on their favorite food plants also serve for their destruction on other crops. Exception is made of insects such as the southern corn root-worm, which is a prime enemy of corn, though the beetles are usually to be found in beet fields, since the elaborate treatment which is often necessary in combating this pest on corn, need not be employed on beets and other crops where its injuries are comparatively insignificant. LEAF-BEETLES AND FLEA-BEETLES. Several leaf-feeding beetles of the family Chrysomelide, known as leaf-beetles and flea-beetles, are quite conspicuous as enemies of the sugar beet. Three of the leaf-beetles are apparently peculiar to beets among cultivated plants, injuring them both in the adult and the larval stage, while numerous flea-beetles, although as a rule general feeders, are even more destructive by attacking the plants early in the season, when they are least able to withstand injury. THE LARGER SUGAR-BEET LEAF-BEETLE. (Monoxia puncticollis Say. ) With the cultivation of the sugar beet in the West there has come to prey upon it a moderate-sized leaf-beetle, known in parts of New .Mexico as the ‘‘French bug.”* Its presence in beet fields was first @See the author’s article, Bul. 18, Div. Ent., U. S. Dept. Agr., p. 95. 10 noticed simultaneously in that Territory and in Colorado in 1898, when it did serious injury to crops. The beetles are gregarious, sometimes occurring ‘*in swarms like blister beetles.” Their brownish gray eggs are deposited in irregular masses, usually on the under sides of leaves. They hatch in about six days, and their larvee or young commence feeding at once, continuing for nine or ten days, when they dig their way into the ground, a few days later coming forth as beetles. Al- though the beetles do much injury, the principal damage is sometimes accomplished by the larve, hundreds being found on a single small plant, which is either consumed or so injured that it shrivels and dies. In 1902 this insect did considerable injury to sugar beet in Colorado. It feeds on several wild plants, blites (Dondia americana and D. Fie. 1.—Monoxia puncticollis: a, female beetle; b, eggs; c, larva, dorsal view; d, larva, lateral view; 4, Claw of male; 9, claw of female—all much enlarged, male and female claws more enlarged (author’s illustration, Division of Entomology). depressa), Russian thistle (Salsola tragus), and saltbush (Atriplea argented), is double-brooded according to Prof. C. P. Gillette,’ and occurs throughout the summer. This species is related to the imported elm leaf-beetle, but is larger and differently marked. The beetle is quite variable, both as regards the markings and size, the length being from one-fourth to one-third of an inch. It is of oblong form, narrow in front. The color varies from pale yellow to entirely black, while the elytra or wing-covers are more or less distinctly striped. The surface of the thorax is coarsely and irregularly punctate. Five varieties or races are recognized. The beet-feeding form is illustrated in figure 1, a. The larva, shown in the same illustration, c, 7, measures when full grown about one-third @Bul. 40, Div. Ent., pp. 111-113. »Twenty-fourth Rept. Colo. Agric. Expt. Sta., 1902, pp. 108-111. ih of an inch in length. The general color is nearly uniform dark olive brown, the conspicuous piliferous tubercles being pale yellow, and the head id portions of the legs black. The eggs (/) are dull brownish gray, and the surface, as seen through a lens, is covered with septagonal and hexagonal areas. A common variety of this species, not thus far noticed, however, i beet fields, is illustrated in figure 2. It has been observed in Nebraska, Texas, and Florida. Remedies.—This and the Western beet leaf-beetle are apt to become important enemies of sugar-beet culture unless remedial measures are instituted. The general methods for the control of leaf and flea- beetles (see page 169) are all applicable, but a few remarks should bé added in regard to particular remedies for these two species. Paris green, London purple, and paragrene have all been employed against the larger species with apparently good results when applied dry, mixed with flour, in the same manner as for the Colorado potato beetle. Against the Western spe- cies a spray of Paris green with whale-oil soap has been used with success, the beneficial effect lasting about six weeks, the beet leaves not being injured. There is no especial advantage in the addition of the soap, and the arsenical used alone or with Bor- deaux mixture would have answered still better. Two interesting facts brought out in the course of Professor Gillette’s observations on the larger insect in Colorado are of value as indicating methods of control. It was observed that the beetles accu- mulated quite largely upon ‘‘ mother” beets early aes cee in the spring, which suggests that if a few beets be —Batural size (author's Fi F illustration, Division left in the ground over winter they will serve as of Entomology), trap crops for the protection of the younger plants in spring. It was noticed also that the insect appeared 4 confine its injuries to plants growing in alkali ground or in close proximity to such soil. Hence such ground is to be avoided for the cultivation of beets. THE WESTERN BEET LEAF-BEETLE. (Monoxia consprta Lec. ) Garden as well as sugar beets are injured by this species, particu- larly along the Pacific coast. It first attracted attention in the years 1890 and 1891 in Oregon, where it did considerable injury (F. L. Washburn, Bul. 14, Oregon Agl. Expt. Sta., p. 11.). It eats holes through the leaves, in some instances leaving only a network of the original leaf, and this seriously interferes with the growth of young plants, which are sometimes killed. 12 This beetle (fig. 3) is smaller than the preceding, measuring only about one-sixth inch in length; is pale yellowish brown in color and moderately variable, some individuals being plain, while others are marked with black spots arranged in nearly regular series. It isa Western species, but ranges as far eastward as the Dakotas, and is found in Montana, Utah, Colorado, Kansas, Arizona, and the Pacific States. There is no record of injury by the larva, but there is little doubt that it also affects this plant, and in much the same manner as does that of the larger sugar-beet leaf- beetle. Injury has been noticed in Oregon toward the end of August, continuing for six or eight weeks. THE SOUTHERN CORN ROOT-WORM. ( Diabrotica 12-punctata Ol. ) Fic. 3.—Monoxia consputa: beetle, ris Rec : er Sr nee ie en lfciear aditennin tt As this species is present everywhere in left highly magnified (original, beet fields the year round, it is familiar to ioe a most beet growers. Theadult is best known in the North as the twelve-spotted cucumber beetle, from its partiality for flowers of cucumber and related plants. In the South the young or larva is called the ‘‘ bud worm” from its pernicious habit of burrow- ing into and eating young cornstalks soon after the germinating period. The beetle (fig. 4) measures nearly one- fourth of an inch in length, is yellowish- green in color, and the elytra or wing-covers are marked with twelve black spots. This beetle is practi- cally omnivorous, feed- ing upon almost any form of vegetation upon which it happens to alight. Although very fond of flowers, yas = 5 ; 5 Fic. 4.—Diabrotica 12-punctata: a, beetle; b, egg; c, larva; d, anal it is liable to attack segment of larva; ce, work of larva at base of cornstalk; jf, pupa— any portion of a plant, all much enlarged except e, which is reduced (reengraved after : Riley, except f [original], Division of Entomology). silane el aiay Fy | oa Se \ rs Ae Sine Gxu. finding food on the foliage and other portions of most garden and many field crops, the flowers and leaves of fruit trees, and the bloom of many ornamental plants. The larva develops on the roots of grasses, as well as corn, and even on beans and some other plants. The beetles have been 13 accused of being carriers of various plant diseases, and probably with justice, since they have a habit of flying frequently from one plant to another, feeding on each in turn. In the leaves of beets and other vegetables they make many small, irregular holes, and are capable of doing considerable damage when occurring abundantly on young plants. It is not known how many generations are produced during the year, but as the beetle is one of our earliest as well as latest species, it seems probable that two or perhaps three generations may be produced annually, at least in the more southern States. Remedies.—Ordinary leaf-beetle remedies are applicable to this spe- cies in its occurrence on beets. On cucumber and other cucurbits, how- ever, it is more troublesome, and must be treated in about the same manner as the striped cucumber beetle (see Circular No. 31, Div. Ent.). On corn it is still more difficult to control the root-worms, and this sub- ject will be reserved for discus- sion elsewhere. The results of experiments with remedies are given in an article on this species by A. L. Quaintance (Bul. 26, n. s., Div. Ent., pp.39-40). THE COLASPIS ROOT-WORM. (Colaspis brunnea Fab.) This species is best known as a depredator upon grape and strawberry, on which the larvee Fig. 5.—Colaspis brunnea: a, larya or root-worm; also subsist, whence two of its b, anal segment of larva from above; ¢, beetle— = > ° all enlarged (a, b, after Riley; ¢, original, Division vernacular names of grapevine of entomology). colaspis and strawberry root- worm, but it has frequently been noticed on sugar beet in Nebraska and Illinois. It is also often found attacking the foliage of beans. The beetle is common and well known. It is exceedingly variable, - but typical specimens are yellowish or pale brown, dull or moderately shining, the elytra and legs are a little paler than the other portions. The form is oval, slightly oblong, and moderately convex, the general appearance being about as represented at figure 5, ¢. The larva“ is a white cylindrical grub, about an eighth of an inch long, with a yellowish-brown head. The pupa is also white and has simple, incurved anal hooks. This beetle has been recorded as doing more or less injury to several plants other than those mentioned, including potato, buck- wheat, corn, clover, beans, cowpea, muskmelon, cotton, and some wild plants, including tick trefoil and New Jersey tea, and the leaves or ‘blossoms of apple, pear, and willow. The larva has also been observed “For particulars the reader is referred to 22d Rept. State Ent. Ill., 1903, pp. 145-149; also Bul. 9, n. s., Div. Ent., p. 21. 14 feeding on the roots of timothy and other grasses, and Indian corn, in addition to clover, strawberry, and grape, which would lead to the belief that the species might have been originally a grass-feeding one. There is little doubt that the insect is single-brooded, and it has been surmised that it hibernates as a partly grown larva. The beetles which are to be found from June to September probably also hibernate. THE BEET TORTOISE BEETLE. ( Cassida nebulosa Linn. ) An illustration of this species (fig. 6) and a short notice of it is pre- sented, for the reason that it is one of the few insects which derive their common names from the beet, and because it is destructive to sugar beet in Europe. There is, moreover, some likelihood of its becoming a pest in our own country if it should ever be able to obtain a permanent foothold here. It is reported as having been observed in Cali- fornia in 1894, but as we have heard little of the insect since that time some doubt exists as to its actual establishment in America. It ranges through Europe and in Asia from Persia to Siberia, and it may be that it is destined to become cosmopolitan. Therefore beet growers should be warned against it. In Europe this beetle feeds on lambsquarters, me Fis iy ia gas Fic. 6.—Cassida nebulosa: beetle, about 4 times natural size Atriplex, and related plants, but when these (original, Division of Ento- nese): plants become exhausted it devastates large areas of sugar beets. There are said to be two generations of the beetles produced annually, one appearing in August, the other in the autumn. The beetle is about one-fourth of an inch long and yellowish gray or pale green in color. Remedies.—The same remedies advised against other leaf-beetles would apply to the present species. THE SPINACH FLEA-BEETLE. (Disonycha xanthomelena Dalm. ) Flea-heetles are among the most important enemies of the sugar beet, and of growing importance, as recent reports bear testimony. No less than a score of species have been observed to attack beets. Among the most destructive of these are the spinach flea-beetle, the pale-striped flea-beetle, and the black and red-headed flea-beetles, well- known forms in the East; but in some portions of the West and else- where others do more damage. They are most troublesome on very young plants. Reports of injuries by the spinach flea-beetle to cultivated plants 15 are rapidly increasing, although it continues to live by preference on weeds and wild plants. The crops most injured are beets, spinach, and saltbush; and natural food plants are chickweed and lambsquar- ters. The leaves of these plants are riddled with holes, chiefly the work of the larvae, but also of the beetles, and gardeners complain that spinach may be so badly worm-eaten that it is impossible to offer it for sale. Considerable injury to beets was observed by the writer in 1900, and during 1902 and 1903 the insect has been the most con- spicuous species on sugar beet in and near the District of Columbia. The larvee, as well as beetles, drop quickly upon being disturbed, and as the former are inconspicuous in appearance, and the latter feign death, the miscreants are apt to elude recognition, the early injury produced being frequently ascribed to cut- worms and the later damage to other insects. Frequently from 15 to 20 larve live on a single leaf. They feed mostly on the under surface. The beetle (fig. 7, @) is shin- ing black, sometimes with a greenish or bluish luster. The prothorax and abdomen are red or reddish yellow, and the legs and antenne pale . Fig. 7.—Disonycha xanthomelena: a, beetle; b, egg mass, yellowish. It measures less showing mode of escape of larva at right; bb, sculpture than one-fourth of an inch. of egg; c, full-grown larva; d, pupa; e, newly hatched The buff or orange eggs (5,25) times nutural size; b, e, more enlarged: bb, still more are deposited in Masses. The enlarged (author’s illustration, Division of Ento- mature larva (c) as it occurs = ™1°8"): on sugar beet is dull leaden gray, with darker head and still darker brown mouth parts, but on red and purple beets it takes on the color of the plant attacked. This is a native species and of exceptionally wide distribution, its habitat extending from New England to Mon- tana, and from British America to Florida and Texas. It is one of our earliest spring visitors, appearing in the first warm days of March in the Atlantic States, and continuing abroad some years through Novem- ber. Two generations occur in the District of Columbia, the first usually produced on chickweed, and later ones on beets, spinach, and other plants. It is a prolific insect, as many as 180 eggs having been observed to be deposited by a single female.” «A more complete account of this flea-beetle is given in Bul. 19, n. s., pp. 80-85. 16 THE PALE-STRIPED FLEA-BEETLE. (Systena blanda Mels. ) peat ata This species, a beet feeder of long standing, has in recent years come to the front as an important enemy to sugar beets, and table beets are also affected. In 1899 and 1900 much injury was done to sugar-beet fields in Michigan, some having been practically destroyed while the plants were quite young. During 1900 much injury was done in Colorado, the beetles appearing in swarms of millions and practically killing plants of two or three weeks’ growth. Older plants were considerably checked in development, but not destroyed. The next year beets were injured in South Carolina and Indiana. This is one of our commonest, most nearly omnivorous, and most destructive flea-beetles. It measures about an eighth of an inch, is cream-colored, with nearly ge, black abdomen and eyes, and 2 ~~ striped wing covers (fig. 8, 0). The larva is white and slender, with light brownish-yellow head. Itisan American species and of rather wide distribution, from New Jersey and Pennsyl- vania southward to Georgia, and westward to California. f The pale-striped flea-beetle, Fic. 8.—Systena blanda: a, larva; b, beetle; c, eggs; though a general feeder, Is fs somone of en ¢ anal tamment ton, ci particularly fond of the foliage e, f, much enlarged (author's illustration, Division of beets and beans. Potatoes Se Bake and corn it also injures very much, while considerable damage to melons and other cucurbits, tur- nips and other crucifers, tomatoes, peas, carrots, and eggplant has been observed. The beetles also attack strawberry, clover, cotton, oats, and peanuts, and injure the leaves of pear, as also pear grafts, by eating out the terminals, thus stunting the growth of the trees. They sometimes do severe injury in three or four days. The species hibernates as a beetle, and appears above ground in the vicinity of the District of Columbia early in June; egg laying evi- dently continues through that month and to the middle of July, if not two or three weeks later; injury is usually due to the beetles upon their first appearance; and almost any valuable crop may be injured, either in the absence or presence of the wild food plants. The larve live below ground, and have been observed by the writer and others feeding on the roots of corn, lambsquarters, and James- town weed. They probably live also on pigweed (Ambrosia), cockle- bur (Xanthium), and other weeds, as the beetles are commonly found on these plants. Wy THE BANDED FLEA-BEETLE. (Systena teniata Say. ) The banded flea-beetle also frequently attacks beets, beans, and other vegetables, particularly in the West and Southwest. It has simi- lar habits to the preceding species and similar structure; it was, in fact, until quite recently very generally confused with the pale-striped form, and many references to injuries by this species are really duc to the latter. Like the latter it varies considerably as regards color and punctation. It is polished black, with white stripes. A common dark form of the beetle is shown in figure 9.¢ THE RED-HEADED FLEA-BEETLE. (Systena fromtalis Fab. ) nose Fie. 9.—Systena teniata, This species (fig. 10) resembles in its habits the tae Mane ae es s two flea-beetles that have just been mentioned. ac canteen OL Its color is shining black throughout except the — Vision of Entomology). major portion of the head, which is red. It has been known as an enemy of beets since 1891. It also attacks potato and beans, but is not restricted to vegetable crops, being quite fond of the foliage of fruits, including grape, gooseberry, pear, and others. It inhabits practically the entire arable region east of the Rocky Mountains, including southern Canada and the Southern States (Bul. Oo, 8. Diy,, lunt., pp. L11=113). THE SMARTWEED FLEA-BEETLE. (Systena hudsonias Forst. ) From the red-headed flea-beetle this differs in being uniformly shining black. Otherwise the Fic. 10.—Systena frontalis— é ; soak c . much enlarged (authors two species are very similar. Taken all in all, it illustration, Division of js perhaps the most abundant of the flea-beetles Entomology). = - . which have been mentioned, but, although it shows a fondness for a number of crop plants, including sugar beet, potato, grape, beans, and sweet corn, if is much more confined to weeds (L. c., pp. 113-114). The larval habits of the three species last mentioned have not been positively ascertained, but there is little doubt that they will be found to be much the same as those of the pale-striped flea-beetle, since the beetles of all of them occur in greatest numbers on the same species of weeds, and, even when occurring in moderate absisdance + seem to show little pr Beareack. «This and the preceding species are discussed in Bul. 23, n. s., Div. Ent., p. 23, 14612—No. 18 = THE WESTERN CABBAGE FLEA-BEETLE. (Phyllotreta pusilla Horn.) @ In some of the Western States not inhabited to any extent by any of | the preceding species there is a small dark-colored flea-beetle uniformly deep polished olive green, with the surface irregularly punctate (fig. 11) which, as its English name indicates, affects more partic- ularly cabbage and related crops. During 1901 it was observed doing considerable damage to sugar beet in portions of Colorado. It prefers the younger plants, and as instance of its destructiveness one grower reported that he had not raised a turnip for seven years on account of its ravages. Between 10 and 20 acres of corn were reported destroyed on one farm in twenty-four hours, the beetles sometimes coming in swarms like black clouds and covering the plants. This flea-beetle ranges from the Dakotas to Mexico, and westward to southern California, being found in numbers at high elevations in the Rocky Mountain region. REMEDIES. The arsenicals, especially Paris green, are the most useful remedies for leaf-feeding beetles, and since Bordeaux mixture is extremely distasteful to flea-beetles, this, if mixed with the insecticide and applied as a spray, is more effective than when the Fig. 11.—Phyllotreta pu @TSenical is used dry. Against some species, how- sila—much enlarged ever, Paris green mixed with 20 parts of flour and (after Riley, Division ars : pb Biden olbey): dusted on infested plants has been found satisfac- - tory, while kerosene emulsion and even strong soap washes have been found useful in combatting others. When the plants are quite young the spray can not be so well used as after they have attained larger growth, but the dry mixture can then be applied with best results. Bordeaux mixture used alone is valuable as a deterrent. Clean culture is also of the greatest value. It consists in keeping down weeds which serve as food for the beetles and as breeding places for their larve. Against the spinach flea-beetle we have to destroy the chickweed and lambsquarters of the vicinity and to avoid the planting of beets and spinach in ground which has become overgrown with these plants. For the pale-striped flea-beetle, lambsquarters, cocklebur, and pigweed should be destroyed, while for insects like the smartweed flea-beetle practically all weeds in the vicinity must be pulled up and destroyed, as this insect feeds on nearly all forms of useless vegetation. The time for performing this work varies according to “In early publications, for example, in the Report of this Department for 1884, p. 308, this insect was mentioned as Phyllotreta albionica owing to the fact that the two species had not been separated, albionica being the older name. 19 the species concerned, and with locality and season. In general terms, it may be said that the best time is after the beetles have laid their eggs and before the young or larye have attained full development. For most species this would be about three weeks after the first appear- ance of the beetles in numbers. . It is a singular fact that in the writer’s experiments the pale Jarva produced the dark form of moth and the dark larva the 14612—No. 48—03 3 as Ne 34 lighter moth. The distribution of this species is wide, including the territory from Massachusetts to the Gulf, and westward to Cali- fornia, but it occurs in greater numbers southward. In the northern portion of its range it is occasionally killed off by exceedingly cold winter temperatures, as happened in 1899. The larve are found abroad from April to November. As with other species which have apparently come northward from the Gulf region, this species is most destructive in the autumn of the year. It is credited with being double-brooded, and possibly three generations are produced in the South. Larve have been observed by the writer to complete their development in a month, and the pupal period varies from 12 to 265 days. The winter is evidently passed in the pupal condition, in which respect this species differs from the ordinary cutworm. THE GREEN BEET LEAF-WORM. (Peridroma incivis Guen. ) In certain years and localities, as in Illinois in 1899 and 1900, this species is more abundant on beet leaves than any other caterpillar. It feeds on both surfaces of a leaf, and has been observed eating purslane, which is doubtless its nat- ural food plant. The larva, also called green cutworm, is green with a white or pinkish stripe on each side of the body. The species is gen- erally distributed, and quite common in Illinois and Ken- tucky, where it is appar- ently double-brooded. NATURAL ENEMIES. 3 Cutworms are exposed to Fic. 31.—Euphrocera claripennis, a common cutworm par- a great variety of natural en- sit Aca i eet ea ce ee ee not eflicient checks except when the cutworms appear in great numbers and travel like the army worms. Atsuch times many species of predaceous and parasitic insects and predatory mammals and birds, wild and domestic, destroy them in great numbers. Of the predaceous enemies ground beetles are most abundant, while the parasites include numerous species of ichneumon and tachina flies and a few chalcis flies. A common species of tachina fly is shown in figure 31. Cutworms are also subject to a fungous disease Empusa aulice. Among birds which are beneficial by feeding upon cutworms are robins, crows, the bluebird, and the bluejay, and among domestic animals are chickens, ducks, turkeys, Guinea fowls, and hogs. 30 METHODS OF CONTROL. From what has been said of the utility of domestic fowls and other animals it is obvious that with proper judgment their services would save great losses that it might otherwise be difficult to avert. Poisoned baits are the standard remedies against cutworms, and to be most effective they should be applied as soon as attack is noticed. They are particularly valuable in cases where the direct application of insecticides to a plant is impossible owing to the danger of poisoning persons or stock when it is used for food. There are two kinds of bait—fresh vegetable and bran mash. Vegetable bait may be prepared as follows: Spray a patch of clover, pigweed, or some useless succulent plant that grows by the roadside or in fence corners, with Paris green, 1 pound to 150 gallons of water; mow it close to the ground, and place it while fresh in small heaps about the infested plants at intervals of a few feet. The later in the day this can be done the better, as the material keeps fresh longer and the cutworms feed almost exclusively at night. Owing to the wilting of this bait, particularly in dry, sunny weather, it is advisable to cover each heap with a chip, shingle, or bit of bark for its protection against the sun’s rays. Bran mash or bran-arsenic mash is of equal value to a fresh vege- table bait, and, according to some, still more efficacious. Paris green, arsenoid, white arsenic, or in fact any arsenical can be used for poi- soning this bait, and in its preparation, on account of the weight of the poison and the fact that it soon sinks to the bottom of the water when stirred, it is best first to mix the bran with water and sugar and then add the poison. ‘The proportions are 2 or 3 ounces of sugar or a similar quantity of glucose or molasses to a gallon of water and a sufficient amount of bran (about a pound per gallon) to make, when stirred, a mixture that will readily run through the fingers. , Before planting a crop it is advisable to employ such bait, and its perfect success is assured by having the ground bare, which practi- cally compels the cutworms to feed upon it. Bordeaux mixture.—This fungicide has been recently tested against the variegated cutworm upon potato vines and asparagus. It was sprayed on as a remedy for blight, and it was discovered that the plants thus treated were free from attack. The use of this fungicide as a cutworm deterrent is certainly advisable. In any case, it should be used as a diluent for whatever arsenical is used. Land methods.—On some plants it is next to impossible to apply any but hand methods with good results. Experiments in Washing- ton State during the season of 1900 demonstrated conclusively that in seme cases it required less time to shake or brush cutworms from affected plants than to destroy them by spraying or otherwise. a6. ‘* Back firing,” a somewhat old-fashioned practice, is of great use in destroying army worms, cutworms, and other forms of insects when they occur in such numbers as to ruin a crop. It consists in burning a rather wide stretch in advance of the wind at the farthest extremity of the field, and then stamping this out to prevent the fire from reach- ing other fields beyond. The field is then burned, beginning with the side from which the wind is blowing. This has the effect of destroying the entire field, with all the cutworms and many other insects which it contains, with practically no danger of the fire spreading to fields where it is not desired. When cutworms assume the habit of traveling in armies they should be treated in the same manner as advised against the army worms. ARMY WORMS. In addition to the army cutworm that has been mentioned and the variegated and spotted cutworms, which sometimes exhibit the same migratory tendency, there are three important species of beet-feeding caterpillars, allied to the cutworms, but lacking the true cutworm habit. The most important of these is the beet army worm. THE BEET ARMY WORM. (Caradrina [Laphygma] exigua Hbn. ) In the year 1899 this species, which had not previously attracted attention by its ravages, became prominent as an enemy to the sugar beet in Colorado. Subsequent study showed that it had been observed at an earlier date attacking crop and other plants in New Mexico and in California. It is an imported pest, and, although not at the present time of great importance, bids fair, in course of time, to become a serious enemy to the cultivation of sugar beet in America. It has evidently come by way of California and is traveling eastward, a method of migration of which there is precedent in the Colorado potato beetle. The moth (fig. 32, a) is mottled gray, resembling the plain form of the related fallarmy worm. The fore-wings are broader and paler, and the reniform and other markings are more distinct. The wing expanse is less than an inch and one-half. The larva is rather slender, with a small head, and the body greenish or olivaceous and striped as shown (fig. 32, 0, c, and fig. 33). When migrating, the beet army worm attacks several forms of veg- etation. Sugar beet appears to be the favorite host plant; table beets are also relished, and it feeds quite as well on lambsquarters, pigweed, and saltbush (Atriplex). When numerous, corn, potato, pea, onion, sunflower, and the leaves of apple, mallow, Vicotiana glauca, Cleome, plantain, and wild grasses are eaten. In southern California the moths appear in April and until June; caterpillars of the first generation 37 develop as early as the last week of May and a month later in June. In the cooler climate of Colorado and New Mexico larvee have been noticed about the middle of June, becoming more abundant in August, when the greatest damage is done. From our somewhat incomplete knowledge of this species it appears that it has a spring and late autumn generation in Colo- rado and New Mexico, and perhaps a third in southern California, and it is evident that the second generation is generally most destructive.“ Methods of control.—Sev- eral remedies have been employed in Colorado with satisfactory results. These include Paris green and kero- sene emulsion, both of which killed the insects and checked their numbers for the follow- ing year. Paris green Was Fig. 32.—Caradrina exigua: a, moth; b, larva, lateral applied as a spray and dry, TeW¢,a%, domal vow: 4, Dead of trio ee mixed with flour. With flour after Hofmann; a-d, after Chittenden, Division of it cost about 80 centsanacre, — *P*°mole8s)- Two sprayings with the liquid preparation were most effectual. When this species is unduly abundant it should be treated in the same manner as the fall army worm (Laphygma frugiperda S. & A.), which is quite often associated with in- jury to sugar beet. The latter attacks nearly all forms of vegetable and other crops, but as it is dis- cussed fully in Bulletin 29, new series, Division of me 3 caraanna «Entomology, further mention is unnecessary here. ged section of first oJ) - proleg segment, dorsal A third species, the true army worm (Leucania view (original, Division ’ * ; Gemntomoloey). unipuncta Haw.), is more strictly an enemy of cereals and grasses, and not, as a rule, of much importance as a beet feeder. Remedies are considered in Circular No. 4, Division of Entomology, and short general accounts of both the true army worm and the fall army worm are furnished in Farmers’ Bulletin 132. WEBWORMS. Among insects that are nearly always to be found in their natural habitat in fields of beets are two small caterpillars known as web- worms. Of these the sugar-beet webworm is a prime beet pest, and the second, known as the garden webworm, is a general feeder, devel- «In a more complete consideration of this species, Bul. 33, new series, Div. Ent., pp. 37-46, references to economic articles by C. P. Gillette and others are furnished. 38 oping on weeds related to beets and invading cornfields and vegetable gardens when the supply of wild food plants and weeds is scant. Still a third species, the imported cabbage webworm, occasionally occurs on beets, but, as its name indicates, it is a cabbage pest, prop- erly speaking, and does not resort to other plants when Crucifere are available. THE SUGAR-BEET WEBWORM. ( Loxostege sticticalis Linn.) @ Although primarily a sugar-beet insect, this species, like many others that have been treated, is a periodical pest, and, as it is an introduction from abroad and widening its range, there is likelihood that it will in time assume greater economic importance. It is cousin to the native garden webworm, but the moth is larger, darker col- ored, and the markings are somewhat more pronounced. With the Fic. 34.—Loxostege sticticalis: a, moth, twice natural size; b, larva, less enlarged; c, upper surface of first proleg segment of larva; d, side view of same; c, d, more enlarged (reengraved after Insect Life, Division of Entomology). wings fully expanded it measures nearly an inch and is of a purplish brown color, with darker and paler bands, as shown in figure 34, a. The pale-yellow eggs are laid singly or in rows of two to five or more, overlapping like scales. The young webworms are whitish, with polished black head and piliferous spots. Mature caterpillars (2) are darker than the garden webworm, with a preponderance in longitudinal markings. It is an inhabitant of western and central Europe and northern Asia, and has evidently, like the beet army worm, been introduced from the Orient on the Pacific coast, and is now slowly but steadily pushing its way eastward. In 1869 it came under observation in Utah, and by 1873 had found its way to Missouri. It occurs southward to Kansas and as far north and east as Michigan, but the major portion of reported injuries have occurred in Kansas and Nebraska. Practically all that is known of the biology of this webworm is from aRiley & Howard, Insect Life, Vol. V, pp. 320-322; Vol. VI, pp. 369-373; Chit- tenden, Bul. 33, new series, pp. 46-49. 39 data accumulated by the Department of Agriculture. The life history has not been followed throughout, but two generations have been dif- ferentiated, and possibly a third is produced in the most southern region which the insect inhabits, the moths from which issue in autumn. Where observed in Nebraska there was a short-lived July genera- : f ‘i } tion, requiring only two . weeks between the matu- rity of the caterpillars and the appearance of the moths, which coupled and deposited eggs for another generation. The caterpil- lars of the July brood transform to pupz almost immediately after entering the ground, but the last generation remains as lar- vee for some time before as- Fic. 35.—Agathis (Cremnops) vulgaris: female, head at lett: guming the chrysalis stage, shin of mle da view, fehl (eden A wild food plant, pigweed or careless weed (Amaranthus), has been observed, and it has been noticed also that injury to fields of sugar beet are most observable where the ground had been allowed to run to this wild plant. In Europe it lives on another pigweed (Artemisia). A parasitic enemy of this species is illus- trated in figure 35. THE GARDEN WEB- WORM. ( Loxostege similalis Gn. ) The garden webworm has the same natural food plant (Amaranthus) as the sugar-beet species, but is Fic. 36.—Lowxostege similalis: a, male moth; b, larva, lateral ae “ view; c, larva, dorsal view; d, anal segment; e, abdominal native to Amer 1E8s and segment, lateral view; f, pupa; g, cremaster—a, b, ¢, f, although widely distrib- somewhat enlarged; d, ec, g, more enlarged (reengrayed ° : : after Riley, except c, original, Division of Entomology). uted 18 somewhat < e- stricted as regards im- portant injuries to the South and Middle West, particularly in States between the Mississippi Valley and the Rocky Mountain region. In 1885 it was the cause of serious trouble over a large area, including five States and Indian Territory.“ It is a general feeder, and attacks most vegetables, cereals, grasses and other forage crops, as also tobacco «Rept. Comm. Agr. for 1885 (1886), pp. 265-270, 40) and sugar-cane, but its injuries are most pronounced on corn and cotton. The moth (fig. 36, 7) is variable from yellow to buff, and there is variation in the degree of markings of the fore-wings. The expanse is about three-fourths of an inch. The larva (4, ¢) is also variable, the ground colors running through pale and greenish yellow to dark yel- low. It seems probable that, as two generations have been observed in the Middle States and three in the South, the life history of this species is not materially different from that of the beet webworm. Eggs are deposited on lower surfaces of leaves, and the caterpillar, soon after hatch- ing, draws together the edges of a leaf by means of its web, or fastens together two contiguous leaves, form- ing a shelter, from which it crawls forth to feed. A parasite of this species is shown in figure 37. Remedies.—Paris green applied as a spray has been used with perfect satisfaction against both of these web- worms, the fact that they are more or Fic. 37.—Limneria eurycreontis: adult female; less surrounded by webs and leaf tis- , abdomen of female, lateral view; sues offering little or no barrier to i Se rani med a the effects of the poison. In addi- tion, clean cultural methods, includ- ing late plowing in the fall followed by deep plowing in spring, and the burning of all waste material and weeds, are of service in control- ling these pests. Early planting is also useful as a safeguard for some crops. MISCELLANEOUS CATERPILLARS. In addition to the caterpillars which have been mentioned—cut- worms, army worms, and webworms—a number of other forms of different classes and with varying habits are so frequently found in beet fields as to deserve consideration. The first two that will be mentioned are naked caterpillars; the last two are hairy cers or woolly bears, as they are familiarly termed. THE WHITE-LINED MORNING SPHINX. (Deilephila lineata Fab.) An illustration and short account of this species, known also as the purslane sphinx, is presented, because it is frequently found in beet fields and evinces an apparent preference for beet among cultivated plants. From its very large size it might be judged a pest of impor- tance. On the contrary, it feeds naturally on purslane, seeming to 41 injure beets only when the former plant is exhausted or unavailable. Occasionally it occurs in some numbers, as has happened in several localities in the past three years, and then may attack various other useful plants, among which turnip, watermelon, buckwheat, grape, and the leaves of apple have been recorded. During 1900 Mr. Edward C. Post reported injury to sugar beets at Dundee, Mich., and Mr. T. Lytle, Manzanoia, Colo., reported damage to tomatoes and to apple and prune trees. Fic. 38.—Deilephila lineata: a, moth; b, pale larva; c, dark form of larva; d, pupa—all natural size (original, Division of Entomology). The resemblance of the adult (fig. 38, a) to a humming bird is marked particularly when the insect is in flight. It will be noted that there are two forms of the caterpillar, a light one (4) and a dark one (c). The insect belongs to the same group as the more familiar tomato and tobacco worms, and its life habits are somewhat similar. Remedies.—On account of the large size of this insect it is not dificult to control it by picking the young caterpillars from the plants and destroying them. They also succumb to the arsenicals. 42 THE ZEBRA CATERPILLAR. (Mamestra picta Harr. ) The zebra caterpillar is a conspicuous garden pest, particularly attached to vegetables, showing some preference for beets and spinach, Fig. 39.—Mamestra picta: a, female moth; b, abdominal segments of male moth; c, pale form of larva, lateral view; d, larva, dorsal view; c, pupa—all somewhat enlarged (original, Division of Ento- mology). cabbage, celery, peas, and asparagus, and feeding at times on nearly all forms of vegetation, including cereals, weeds, and the foliage of a b Cc Fic. 40.—Mamestra picta: a, b, newly hatched larva; ¢, larva of third stage—much enlarged (original, Division of Entomol- ogy). presented in figure 40, « trees. As previously mentioned, it bears the distinction of being the first insect reported to affect beets in this country. The moth (fig. 39, @) resembles in general contour the progenitors of cutworms belonging to the same group of insects. It has a wing expanse of about an inch and a half; the fore-wings and thorax are brown, shaded with darker purplish brown, and the hind-wings are white, tipped with pale brown at the margins. The larva or caterpillar (fig. 39, ¢, d) is somewhat variable, but the head is red and the ground color yellow, more or less strongly marked with black, the stripes on the sides suggest- ing the name of zebra caterpillar. The larva when first hatched from the egg is dull gray and looks quite unlike the mature form. Two views of the newly hatched larva are 1, 6, while the third stage is shown at c. This species is quite abundant in the North, becoming most trouble- 43 some in the second generation, which usually appears in September. In addition to the plants that have been mentioned as furnishing food for the zebra caterpillar are cauliflower, turnip, beans, carrot, potato, corn, currant, cranberry, willow, roses, and others. The winter is passed in the pupal condition, and the moths appear in May and June. The first eggs hatch in a moderate temperature in six days, and the larval period is about five weeks. The pupal period is very long, lasting, as observed by the writer, sixty-seven days, making in all a period of one hundred and ten days from the time the eggs were laid until the moths appeared, late in August. This species can endure a considerable amount of cold, but is very susceptible to parasitic attack, and to a less extent to fungous diseases. Methods of control.—The caterpillars when first hatched are gregari- ous, hence easily discovered at this time and destroyed by hand or by poisons. They yield readily to sprays of arsenicals, but these are not necessary in ordinary cases of attack. THE SALT-MARSH CATERPILLAR. ( Leucarctia acrxea Dru.) Several forms of hairy caterpillars, such as the yellow bear (Spd/o- soma virginica), of similar appearance and habits, are commonly found on sugar beet. One of these, known as the salt-marsh caterpillar ay ChTAL Fig. 41.—Leucarctia acrea: a, female moth, b, half-grown larva; ¢, mature larva, lateral view; d, head of same, front view; e, egg mass—all slightly enlarged except d, more enlarged (original, Division of Entomology). : (Leucaretia acrea Dru.), from its ravages early in the past century upon forage crops grown in the salt marshes of New England, is occa- sionally troublesome in beet and corn fields and in gardens. 44 This caterpillar differs from the common yellow bear in having a darker body, and the sides are distinctly ornamented with yellow markings. The two species are of about the same length, and the hairs present a similar variation in color. A young larvais illustrated at figure 41, b, a mature one at ¢c. The moths also closely resemble each other, but the fore-wings of the present species are strongly marked with black, and the abdomen, with exception of: the first and last segments, is bright ocher above, with black markings. In the female the hind-wings are white, like the fore-wings, and similarly marked with black, but in the male they are ocher with two black dots (fig. 41, a). The life economy of these species is very similar; they form the same sorts of cocoons and transform in any convenient place where shelter can be obtained. In New England the salt-marsh caterpillar is credited with having a single generation, but a little far- ther south, in the Middle States, two generations have been recognized. THE HEDGEHOG CATER- PILLAR. (Isia [Pyrrharctia] isabella S$. & A.) Another conspicuous cat- erpillar known to attack beets is shown in the accom- Fic. 42.—Isia isabella: male moth above; caterpillar, side panying illustration (fig. 42). Ce Tet Shaoudl eaicaslaep). | Lbs recorded. cece peas and corn, but appears to prefer plantain and other weeds, such as dandelion and burdock. The general color of this caterpillar is bright cinnamon red and usu- ally each end is black. The long hairs with which the body is covered are so evenly distributed as to give it the appearance of being shorn or cropped. The name of hedgehog caterpillar is derived from the habit of this insect of rolling up when disturbed and of passing the winter under the bark of trees or in some similar location rolled up like a hedgehog. The life history of this insect is very similar to that of the preceding. The moth (fig. 42) is dull orange, with the fore-wings marked with dusky stripes, both the fore and hind-wings being spotted with black, the latter a little paler than the others. 45 Remedies.—As a rule neither this insect nor the salt-marsh cater- pillar occurs in troublesome numbers; hence remedies are not often necessary. It can be controlled by ordinary methods of spraying and hand picking. GRASSHOPPERS, CRICKETS, AND RELATED INSECTS. Of great economic importance in the West, and in some seasons in other regions, are numerous species of locusts, popularly termed grasshoppers. Several forms of related insects, such as katydids and crickets, are also injurious, but all of these insects are general feeders, and as a rule destructive to sugar beets and other vegetable crops only in seasons which have been particularly favorable to their multiplica- tion, and their operations are mainly confined to fields adjacent to grass lands. The numbers of these insects mount into the hundreds, but the really important species might be reduced to between twenty and thirty. Fourteen are listed as sugar-beet pests. For present purposes it will be necessary to mention specifically only a few of the most abundant of the grasshoppers. Like most other forms of the order Orthoptera, they are mostly large insects, with mouth parts formed for biting, and with incomplete metamor- phoses, the young more or less closely resembling the adults, save for the lack of wings. Their name is sufficient indication of their habits: They live normally on grasses for the most part, and their thighs are large, fitting them for long leaps. Everyone knows them so well that further description is unnecessary. Some species are capable of extended flight for hundreds of miles, with occasional intermissions daily for food. In their migrations they go in swarms, and sometimes darken the face of the sun, or at night of the moon. Grasshoppers may be classified, as regards their habits, as nonmi- gratory and migratory. The former breed and pass their entire lives in or near the place where the eggs were laid. The migratory species breed in enormous numbers, and when they become too abundant for the limited food supply of a region, they develop the migrating habit and travel in swarms. These insects are particularly abundant and troublesome in arid and semidesert regions, and as their numbers are subject to great variation according to climatic and other conditions, the visitation of a locust swarm may be expected at any time during the warmer months of the year. In dry regions locusts are the most dreaded of insect pests. Because of their voracity and the rapidity of their attack, they lay waste entire townships, counties, and even large portions of States. 46 THE RED-LEGGED LOCUST. (Melanoplus femur-rubrum De G.). This is our commonest North American grasshopper, being found practically everywhere. It is one of the smaller species (fig. 43), and where it is not held in subjection by numerous natural enemies of various kinds it may become a decided nuisance in cultivated lands. It was destructive Fig. 43.—Melanoplus Seen tae ne wae beet sas Hlinois in 1899. It sel- utal ize (after Hiley). dom exhibits the migratory tendency, but sometimes gathers in swarms and moves in concert, not, however, rising to great heights, but drifting with the wind as do the true migratory species. THE ROCKY MOUNTAIN LOCUST. (Melanoplus spretus Thomas). This is the most destructive of all native grasshoppers, and has been the cause of greater losses to agriculture in the past thirty years or more than perhaps al! of the other known species of grasshoppers combined. Its range of injuriousness is not limited to the Rocky Mountain region, but it is more abundant there than elsewhere. It is illustrated in figures 44 and 45. Those who were inter- Fic. 44.—Melanoplus spretus: a, a, a, female in different posi- tions, ovipositing; b, egg-pod extracted from ground, with the end broken open; c, a few eggs lying loose on the Fie. 45.—Melanoplus spretus: a, a, ground; d, e, show the earth partially removed, to illustrate newly hatched nymph; b, full- an egg-mass already in place and one being placed; /, shows grown nymph; ¢, pupa, natural where such a mass has been covered up (after Riley). size (after Riley). ested in farming in the 70’s in Kansas, Nebraska, and some neighbor- ing States have cause to remember the depredations of the Rocky Mountain locust. During 1874-1877 it was directly responsible for the loss of $100,000,000, in addition to an indirect loss by the stoppage of business and other enterprises which might have aggregated as much more. It was for an investigation of this species that the AT United States Entomological Commission was formed, which published from 1877 to 1879 two voluminous reports on it alone. For particulars see Bul. 23, 0. s., Div. Ent., p. 17. 14612—No. 43—03——5 66 but the lower surface is reddish brown and the legs are clothed with reddish-yellow hairs.“ Pemedies.—Unfortunately the carrot beetle works under ground, like common white grubs, and for that reason is as difficult to control. Injury is largely confined to the beetles, although the larve do some injury. If we could ascertain the principal breeding places, this might furnish a solution of the problem. The grubs may be treated as described in preceding paragraphs. Ina case of reported injury to the roots of sweet corn in Minnesota in 1902 the presence of the carrot beetles was traced to their having developed in horse manure on the infested grounds;? hence avoiding the use of this as a fertilizer or the destruction of the white grubs in the manure is recommended. Crop rotation is one of the best remedies, and it is probable that trap lights might yield good results, as these insects are more attracted to bright lights than are ordinary May beetles, although it is not known to what extent the beetles might be lured from the fields after they have begun to feed. WIREWORMS. The sugar beet, as has been said, is so nearly exempt from injury by wireworms that this plant, as also spinach, might be profitably used as an alternate in the cultivation of corn, various other cereals, and vegetable crops, such as potatoes, which are frequently very badly infested by these insects. Occasionally wireworms of several species have been found eating into the smaller roots of beets and burrowing into the tap roots and crowns, causing the plants attacked to shrivel and die. Messrs. Forbes and Hart have indicated two species of wire- worms as having been concerned in such injury, d/elanotus cribulosus and Drasterius elegans, both of which have been observed about beet roots which had been more or less injured and eaten away. The term wireworm is applied to numerous forms of elongate wire- like creatures, the larve of snapping beetles or ‘‘snap-bugs,” of the family Elateridee. Many species are injurious to cultivated crops and are often very troublesome in cornfields. A large proportion of the wireworms are shining yellow in color, while many of the adults, like the species figured, are brown and covered with close brown or yel- lowish pubescence. The life history of injurious subterranean species is in some respects similar to that of white grubs, the beetles being among the earliest spring arrivals, occurring in April and May, and flying rapidly in the heat of the day. The eggs are generally deposited in moist places grown up with grassy vegetation, weeds, or corn, and the larve upon hatching feed, aA more complete account is given on pp. 32-37 of Bul. 33, n.s., Div. Ent. 6 Washburn, 7th Rept. Ent. Minn. for 1902, pp. 47-49. 67 like the white grubs, upon the roots, developing slowly and requiring about the same period for the perfection of the life cycle—about two or three years. Like the white grubs, also, the wireworms transform to pup in autumn, and the change to the beetle form takes place before winter, the beetles usually remaining in a quiescent state until their emer- gence the following spring. Two common and injurious species are chosen as examples of this class, althongh it must be remembered that they have not been determined as beet feeders. The first is known as the wheat wireworm (Agriotes mancus Say), and is shown four times natural size in figure 61. The other is called Monocrepidius vespertinus and is intro- duced here because known in its three principal stages (fig: 62). Remedies. Owing to their extremely hardy character, indicated by the SY ey 2 hard, firm texture which has given them ” anal ot PRERPEY Toe ta a ees the name of wireworms, as well as to four times natural size (author’s illustra- their subterranean nature, these insects 10% P!¥#sion of Entomology). are even more difficult to treat satisfactorily than the white grubs. Of direct applications. poisons are of little value, but salt in large quantity has been used by some persons with success for many years, and has been reported to he one of the most effect- ive applications that can be made. Strong brine, however, must be used with caution, as it some- times destroys certain forms of plant life. Dif- ferent forms of salty fertilizers are also said to be of value, both as Fic. 62.—Monocrepidius vespertinus: a, larva, side view; b, same, stimulants to the affected dorsal view; @, beetlerd-pupa—about three and one-half plants and as insecticides. times natural size (author’s illustration, Division of Ento- 5 ; x ae mology). Among these are kainit and nitrate of soda. Clean cultivation and poisoned baits are also recommended, the same as for white grubs. In fact, where remedial measures are in use against either cutworms or white grubs, they apply also to wireworms, but are less effective. 68 One of the best forms of bait to be used consists of slices of potatoes or other vegetables poisoned in the same manner as advised in the consideration of cutworms. MISCELLANEOUS ROOT-INFESTING INSECTS. In addition to white grubs, wireworms, and root-lice, which have been treated as invading the underground portion of beets, a few other species are found at the roots. Prominent among such are the seed-corn maggot and the clover-root mealy-bug. A number of com- plaints have been made of injury by insects which lead to the belief that the seed-corn maggot is frequently found on beets, although instances which could be positively traced to this species are com- paratively few. THE CLOVER-ROOT MEALY-BUG. ( Dactylopius trifolii Forbes. )@ This species, as its common name indicates, is better known as an enemy of clover, on the roots of which it feeds. In 1901, however, it appeared in considerable numbers on sugar beet in Michigan, the smaller stunted roots being invariably infested. Injury was most apparent in June. The female mealy-bug measures a little more than one-twelfth of an inch in length, is reddish brown, and covered with a waxy or mealy secretion. The legs are dirty yellow, and from the sides project in the manner usual to this group 15 to 17 waxy fila- Fic. 63.—Dactylopius citri: fe- ments, the shortest being near the head and male—enlarged (Division of ; A ° En onneneee the longest near the tail, sometimes one-third as long as the body. It is related to the scale insects and is of similar appearance to the species shown in figure 63. Remedies.—The same methods of control that have been prescribed for root-lice would operate against the present species, with about the same results. THE SEED-CORN MAGGOT. (Pegomya fusciceps Zett. )? Beet roots are subject to attack by the above-named species of root maggot. During November of 1902 we received complaint of what was with little doubt this insect from Colorado, where it was breeding in rot-infected roots, apprehension being expressed that “Syn: Coccus trifolii Forbes; 14th Report State Ent. Ill. for 1884 (1885), pp. 72-73; Pettit: Bul. 200, Mich. Agr. Exp. Sta. for 1901 (1902), pp. 193-194; Davis: Insect Life, Vol. VII, p. 172. bSee Bul. 33, n. s., Div. Ent., pp. 84-92, for synonymy, bibliography, ete. 69 although injury was not then noticeable the insects might do damage the following spring. Such a sequel is often to be expected, and it seems probable that many reported instances of injury by this and related forms of maggots are due to their habit of developing on decaying vegetable and other matter and afterwards attacking roots and taproots and other healthy vegetation of the vicinity. Most vege- tables, more particularly beans, peas, and maize, are subject to damage, and cabbage, turnip, radish, onions, and sweet potatoes are also much affected. The insect which is generally distributed in the United States is shown in its different stages in figure 65. It resembles the beet or spinach leaf-miner previously considered. The particularly distin- guishing characteristic of the fly consists of a row of short bristly hairs of nearly equal length on the inside of the posterior tibie of the male (fig. 64, 7). The length of the wing is about one-fifth and of Fic. 64.—Pegomya fusciceps: a, male fly, dorsal view; b, female, lateral view; c, head of female, from above; d, larva, from side; e, anal segment of larva; 7, anal spiracles; g, thoracic spiracles; ), pupa- rium—all much enlarged (author’s illustration, Division of Entomology). the body about one-sixth of an inch. The maggot as Well as fly resembles the onion maggot. There is little doubt that this insect is of European origin, and it is certainly increasing in destructiveness in this country. Remedies.— Owing to the difficulty of destroying subterranean pests and the cost of chemicals for the purpose, such as bisulphid of carbon, we have to depend more upon methods of prevention. One way of deterring the parent flies from depositing their eggs consists in the use of sand soaked in kerosene—a cupful to a bucket of dry sand— which is placed at the base of the plants, along the rows. This also kills young maggots that may attempt to work through the mixture. Fertilizers are also useful as deterrents, particularly when employed just before or after a shower has thoroughly wet the ground. They should be applied as nearly as possible to the roots, and the earth 70 should be turned away from the plants for this purpose. They pos- sess the advantage of also acting as a stimulant to plant growth. Stable manure is apt to induce infestation, as this species is well known to develop in excrement and other decomposing material. As soon as plants show signs of wilting and maggots are known to be present, the injured plants should be promptly pulled and destroyed. The above methods have been used with success against onion mag- gots and similar root-feeding species, and may be all that is required in the case of ordinary infestation of beets. One of the best remedies for root maggots is bisulphid of carbon. It has been used with more or less success by Prof. A. J. Cook and others since 1880. Im its application great care should be exercised that the liquid shall not come in direct contact with the roots of the affected plants. Directions for the treatment of plants affected by - root maggots are furnisned on page 14 of Farmers’ Bulletin 145, a copy of which can be had upon application to the Secretary of Agriculture. THE RED SPIDER. The common or two-spotted red spider (Zetranychus bimaculatus Harv.) is usually present in most fields of sugar beet east of the Rocky Mountain range, but it is preeminently a greenhouse pest, and as a rule does comparatively little injury to plants growing out of doors. It is unique as a vegetable pest in that it is not a true insect, nor even a spider, as the popular term would imply, but a spinning mite. As the word mite indicates, these creatures are extremely minute, and are frequently not noticed until they become excessively numerous, as is apt to happen during summer droughts. They do considerable dam- age in flower and vegetable gardens, but attain their greatest destruc- tiveness in connection with plants grown under glass. The general appearance of the common red spider is shown in figure 65, highly magnified. The length of a full-grown individual is only about one-fiftieth of an inch. The ground color is reddish, usually more or less tinged with yellowish or orange, and most individuals have a dark spot on each side, due to the food contents of the body. The young are similar to the adults, differing in having only three pairs of legs, while the adults have four. This red spider spins threads, but does not use them for climbing. The threads are frequently so numerous as to form a tissue visible at a little distance. Webs are usually constructed on the under sides of leaves and within them the mites feed and lay their eggs from which the young develop. This red spider is quite likely of foreign origin, but its distribution has not been carefully studied. It is inclined to be omnivorous, attacking a wide range of plants. As the red spiders increase in number the leaves of an affected plant ti > turn pale and become stunted, and eventually the whole plant succumbs unless remedies are applied. Cuttings and young rooted plants are especially susceptible to injury, and more particularly in spring. These mites injure by suction, slowly reducing the vitality of plants until in time their functions are more or less deranged. Among ornamental plants that are much affected are violet, rose, clematis, minuet, pink, fuchsia, pelargonium, godetia, passiflora, feverfew, thunbergia, verbena, heliotrope, moon- flower, calla, smilax, and Easter lily; while of other crops, beets, beans, sage, tomato, eggplant, pepper, cucumber, squash, cowpea, hops, and berries of various kinds are attacked. As a rule this species is not especially narmful to the sugar beet but is quite destructive at times in fields of other crops; for ex- ample, to beans, which have been badly injured in South Carolina in recent years. Remedies.—This red spider is resistant to ‘‘ gassing” or fumigation, either with \ a oq tobacco or hydrocyanic-acid gas. It 19; Fie. 65.—Tetranychus bimaculatus: a, however, peculiarly- susceptible to sul- sae pire wae aac ai phur, a sovereign remedy for mites in general. Flowers of sulphur mixed with water at the rate of 1 ounce - to the gallon and sprayed over the plants is of great value in its eradi- cation; or the sulphur may be combined with a wash, for example, with strong soapsuds, Potash, fish oil, whale oil, and other soap solutions, resin wash, and kerosene-soap emulsion are also valuable, and the addition of sulphur increases their effectiveness; but these washes are too strong for some delicate plants and are apt to injure them. For violets and similar plants, as they occur in greenhouses, no other remedy is used by flor- ists generally than frequent syringing or spraying with water or with a solution of neutral soap. Directions for the application of the soap washes to violet and other greenhouse plants are furnished in Bulletin 27, new series, of the Division of Entomology (pp. 40-42). O 5 UD ee 6 i A Ss ORAS ress nitro “Rll lpia eee aan ico » e La VAT ae Vere 4 ¥ Rig ae wk Lives 0: af AS err vied eee oe a yee mee PVA ¢ : ‘A a MISCELLANEOUS RESULTS y OP THE DIVISION OF ENTOMOLOG\ oe a PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST. — 4) eh i we De -. © WASHINGTON: - | ‘GOVERN MENT PRIN TIN @ OFFICE, DIVISION OF ENTOMOLOG ¥. i L. O. Howarp, Entomologist. C. L..Maruart, in charge of experimental field work. F. H. Cairrenpen, in charge of breeding experiments. — A. D. Hopxiys, in charge of forest insect investigations. FRANK Benton, in charge of apiculture. W. D. Honter, in charge of cotton boll weevil investigations. A. L. Quatnrance, in charge of bollworm investigations. D. W. Coquittertr, TH. PeEr@ANDE, NATHAN Banks, Assistant Entomologists. FE. A. Scuwarz, E. 8. G. Trrvus, Investigators. Miss H. A. Ketuy, Special agent in silk investigations. >, R.. 8. Cuirron, F.C. Pratr, August Buscx, Orro HEIDEMANN; A. UN; CavupDEL 1y J. Kotrnsky, H. S. Barper, Assistants. W. E. Hinps, W. F. Fiske, G. H. Hargis, H. E. Burks, A.W. Morri, J.-C, Crawrorp, Jr., A, A. Grravut, C. T. Bruxs, F. C. Bisnory, Serrycer Gors, C. M, Waker, Zemporary field agents. Miss L. L. HoweEnstern, girlies, t Pier ie ey » OF? AGRICULTURE, DIVISION OF ENTOMOLOGY—BULLETIN NO, 44, L. O. HOWARD, Entomologist. ape eek ie aD MISCELLANEOUS RESULTS OF THE WORK OF THE DIVISION OF ENTOMOLOGY. PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1904. LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, Division oF ENTOMOLOGY, . Washington, D. C., February 24, 1904. Str: I have the honor to transmit herewith the manuscript of a bulletin which contains several articles and notes similar in nature to those which have been presented in previous years under the title, ‘*Some miscellaneous results of the work of the Division of Entomol- ogy,” and recommend that the material here presented be published as Part VII of that series. The introductory article on aphides affect- ing grains and grasses is of special value to the economic entomologist, as the identity of many of these species has been in a state of confusion for a number of years, and the descriptions here furnished, together with the illustrations, will assist materially in simplifying this matter. For many years there has been great demand for a publication cover- ing the subject of the weevils which affect chestnut, as also pecan and hickory, and the article presented on this subject will, in part, fill this want. The remaining articles are mostly shorter, and each has its special value. Respectfully, L. O. Howarp, Entomologist. Hon. JAMES WILSON, Secretary of Agriculture. bo CONTENTS. On Some or THE APHIDES AFFECTING GRAINS AND GRASSES OF THE UNITED en Ee GUTS Grebe Gs) eae evens aioe Sie et eS Theo. Pergande. - The European Grain Louse (Siphocoryne avene Fab.).......----------- The English Grain Louse (Macrosiphum granaria Buckton) ..-.-.-------- The German Grain Louse ( Macrosiphum cerealis Kalt.)........---------- The Clover Plant-Louse (Macrosiphum trifolii n. sp.).----.-------------- THE CuHestnut WEEVILS, with Notes on OTHER Nut-FEEDING SPECIES (il’us- (PEG RECG DE SRS eh Rea eae) ek 3 See eee nee ee eee F. H. Chittenden. - Trot CTS EO ay ere eee eek ee ics cea emt ee, Sete Ah Sh Ste Soest Se The Chinquapin Weevil (Balaninus proboscideus Fab.).....----.-------- he Chestnut Weevil (balanimus- rectus Say) -4.2-4.-552-222-5,--24 2. - Pood Habis orepecies of Nut.Weevils...-. 02-26 .222260.-.2-24 0222-4 sire pnte Kory =nUb WW Coyle. eee enc ae oe malts, e Ua ene eee oe ie IOMrIOMGO MUG assert sea ee eens oe ee ee a OT Sees ce The Acorn Moth (Holcocera glandulella Riley)--.-...-.--------------- Tar Cowrea-Pop Wrevit (illustrated) ...--....--...--.- F. H. Chittenden. - ADDITIONAL OBSERVATIONS ON THE Topacco STALK WEEVIL-....-.-.---------- Report oF INVESTIGATIONS AND EXPERIMENTS ON FULLER’S Rose BEETLE IN SGT MEN Wi O-AMMOMO NIV AD. 2 clase. pes ele wl ato Oe ee fone Fdk. Maskew. - IMPORTATIONS OF BENEFICIAL INSECTS INTO CALIFORNIA..-.-.-- C. L. Marlatt. - Insects Injurious To Stock IN THE VICINITY OF THE GuLF BioLoagic Sra- TELL eee Pan ee ees ey ele ety Fy ep de ite ko LS ea te BR James S. Hine. - Ture New DISTILLATE SPRAY IN CALIFORNIA'.......-..--.----( . DL. Marlatt. - @ THREE British FrRvuIT-TREE Pests LIABLE TO BE INTRODUCED WITH IMPORTED Teese TSAO GA eS ae PRE a Mea a ea ae ei ae ee ea Fred. V. Theobald. - Tue Cuerry Fruit-rry (Rhagoletis cingulata Loew) (illustrated). F.. H. Chittenden. - ON THE ORIGIN OF THE NATURAL CoLORATION OF SILKs OF LEPIDOPTERA. G. Leverat and A. Conte. - Some PRELIMINARY NOTES ON THE CLOVER-SEED CHALCIS Fiy (Bruchophagus Wencoris tomer, |) cilidetrated ) 222. .2..5. iss. ee tec ek ESS: G. Titus. Lire History oF THE SALT-MARSH CATERPILLAR (Lstigmene acrea Dru.) at Wein UN ones Ulistrated)) «.0----cfe.25--lesee-cosebae Se W. E. Hinds. - At ON ERE N O Mpetee yee Satta ciel ave acter inl oa Sate Sele Sui= S_ Salsas eiefovarecs Some Injurious Garden and Field Insects in Tropical America (p. 84) ; Aquatic Bugs of Commercial Value as Food (p. 86); Injury by a Cricket in the South (p. 88); Identity of a Tingitid found on Chrysanthemum (p. 89); Carbon Bisulphid for Red Ants and White Grubs (p. 90); Agonoderus pallipes a Permanent Enemy of Sprouting Corn (p. 90); Abundance of the Rhinoceros Beetle in South Carolina (p. $1); Length of the Fiber in the Cocoon of the Domestic Silkworm (p. 91); The Quail as a Destroyer of Cutworms (p. 92); Hair-worms in Cabbage (p.93); Observations on the Habits of the Morning-Glory Leaf-cutter (Loxostege obliteralis Walk.) (p. 95); New Habits of the Cucumber Flea- beetle (Epitrix cucumeris Harr.) (p. 96); On Remedies for Garden Snails ea ap: 96): “Presented by title before the St. Louis Meeting of the Association of Economic Entomologists, Dec. 30 and 31, 1903. 3 Page. 4 CONTENTS. Noris: FROM (CORRESPONDENCES: . S25 oes nee oe Ce a ee ee Fia. The Bollworm at a High Elevation (p. 97); Supposed Cutworm ima to Orange Fruit (p.97); Remedy for Cabbage Worms and Plant-lice (p. 97); A Cabinet Beetle in a Locket (p. 97); Food Habits of a Tree Cricket (p. 97); A Food of Robber-fly Larvee (p. 98); A Tachina Parasite of May Beetles (p. 98); Strange Habits of a Tropical Cricket in South Caro- lina (p.98); Kerosene as a Remedy for the Clover Mite (p. 98); Car- nivorous Habits of Polystachotes punctatus Drury (p. 98); A Mite in Sugar Withstanding Severe Cold Weather (p. 98); A Mushroom- infesting Mite (p. 98); A Myriopod Stated to Injure Vegetation (p. 99). ba SSR Ao Nese Piare I.—Distillate power spraying apparatus used in San Bernardino County J 5 ov) California as t22 a0. eed oe ee Se eee eee Siphocoryne avene: sexes'and details |. 44.4 <<¢ 32 2. oa -ee e ee Macrosiphum granaria: migratory female and antenna -----.-.-------- Macrostphum cerealis: migratory female: . =. + 222.2 5-25 2> =e sae Macrosiphum trifolii: migratory female .......-.-.----------------- Chestnuts showing exit hole of larval weevil ---....----.---------- Balaninus proboscideus: adult, dorsal and lateral views - .------------ Balaninus proboscideus; larva 22556 25 5. Sees ae 6 aaa ee ee 8. Balaninus rechis: male and female _- 24 22-52 -2 23a ee 9. Balaninus weloriensiss adult 22255 45>) 2: Sie 3-3 2 ee ee 10; “Pecan nuts showing injury by weevils... 20.2_-. =: --- Stee ee cee 11. Balaninus carye: male and female ------------ See eee 12. Holeocera glandulella> ‘ditferent ‘stages of... 8 es 13«.Chalcodermus.eneuss Gilleretit Stagesac> s26 see 14. Chalcodermus seneus: lateral, views < 5s: 4-2 02422. 2 ae ee eee ben Chalcodermus zeneus: work OF larva 2 -- —- 2-5-2 eee G5 a CRALCOMeRNitEs GONGTISS ACLU ie ss ee pe ey ee 17. -Rhagoletis cinguiata: different ‘stages <. -.22-0-.=22 202 ee ee 18. Conotrachelus nenuphar: different stages... -----2-=----26 222s 19. Estigmene acrxa: different stages -..--.--------- eee Set eet) Hoyts MD Page. 60 10 16 20 22 24 SOME MISCELLANEOUS RESULTS OF THE WORK OF THE DIVISION OF ENTOMOLOGY, WE: ON SOME OF THE APHIDES AFFECTING GRAINS AND GRASSES OF THE UNITED STATES. By Tro. PERGANDE. THE EUROPEAN GRAIN LOUSE. (Siphocoryne avene Fab.—Fig. 1.) Up to the present time the writer has been unable to ascertain whether other species described in Europe or this country are identical with this insect or not, though it is quite certain that the accounts or descriptions published by the earlier entomologists of this country on the apple louse all refer to the same species, particularly since the genuine Aphis mali DeGeer was first observed by the writer in the spring of 1897, from which date it has spread through several of the Eastern States. The first elaborate account of the common apple louse of the United States was published by Dr. Asa Fitch in his First and Second Report for 1856, under the cognomen of ‘*The apple plant-louse,” which he erroneously considered to be identical with the European Aphis mali, to which since his time it has been referred by subsequent authors. These authors took it for granted that Doctor Fitch knew the species well, though all of them were unaware of the range of food plants to which the species adapted itself during its cycle of existence. It is really strange that Fitch, after having seen thousands of the apple louse, should have considered the insect found by him on the leaves of the plum to be a different species, which he subsequently described on page 123 of the same report, under the name of Aphis prunifolix, notwithstanding that, as stated by himself, ‘‘ Its generation and hab- its are so similar to those of the apple plant louse that a separate account would be little more than a repetition of what has already been related.” .To make the history of the species still more complicated, leading later on to many errors, Fitch published (on pp. 91, etc., of his Sixth 5 6 Report for 1856) a very interesting article on the grain Aphis (Aphis avene Fab.), in which he made the unfortunate mistake of confound- ing several other species with the true grain louse; erroneous figures of one of which were published on PI. 1, figs. 5 and 6, representing a species of Siphonophora Aoch. This error of judgment in distinguish- ing genera as found upon grain has mainly been the cause to divert the attention of later entomologists from the true characters of the species described by Fabricius. Until the spring of 1880 the writer also entertained the opinion that the species treated of by Prof. Cyrus Thomas, in his Eighth Report (pp. 51-55), was identical with that mentioned and described by Fitch as Aphis avene Fab. During the spring of 1880, however, the writer’ became suspicious that something was wrong, since the description given by Thomas did not agree with that published by Fabricius. At that time I happened to examine a lot of aphides from Pocomoke City, Md., which were reported to be extremely numerous and destructive to wheat in that vicinity. These, in my opinion, agreed exactly with the description of Aphis avene Fab., and Kaltenbach, but not with the description by Thomas, and I have held to this opinion ever since. The same form, having been found by myself or received from various localities, infesting grains or grasses, agrees well with the description of the species published by Fitch, but not with that of Thomas. In consulting Mr. O. W. Oestlund’s description of his Vectarophora granaria (Aphidide of Minnesota, p. 82, 1887), I am forced to believe that the species observed by him is also the same as the A. avene Fab., though, having failed to obtain any specimens from him, I am unable, at present, to verify my suspicion. While consulting the original notes of Doctor Fitch, I found also a clipping from the Kingston (Canada) Daily News, of August 16, 1866, containing an article on the grain louse which was doing much damage at the time. The article was written by a Mr. Lawson, of the Botanical Society of Canada, who considered the insect as new, and in the same article he described it under the name of Aphis tritici. After a care- ful scrutiny, Iam confident this is the same as A. avene Fab., but, since descriptions of insects in newspapers are not considered as authori- tative, I have declined to recognize his name of the species. During the fall of 1880, while solving the life history of the hop louse (Phorodon humuli) at Richfield Springs, N. Y., at a time when the return migrants of the apple louse were very abundant on the leaves of apple trees or still swarming, I happened to discover also some colonies, both of the migrants and the apterous forms, in various stages of development on the leaves of a grass, Dactylis glomerata, erowing in the orchard. After careful comparison of these with others on the apple, which, up toa comparatively recent time the writer had considered identical with the European apple louse, 4. mali DeG. 7 Some years ago I examined and compared a number of specimens, labeled by Fitch, and now contained in the collection of the United States Department of Agriculture, both of his A. ma// and his A. avene, as well as a number of specimens of A. avene kindly sent me by Dr. H. Schouteden, Brussels, Belgium, all of which confirmed my opinion which is that the American apple louse and the grain louse are identi- eal, and that the European A. mali, of which the first American colo- nies were found in the spring of 1897, is quite a distinct species, not even generically identical with the genuine grain louse of Europe, nor with the grain louse described by Thomas as Siphonophora avene. On further examination and comparison of the insect under consideration, I have concluded that it belongs to the genus Siphocoryne of Passerini, described in ‘* Aphididx Italicee” (p. 52, 1863). He there states that the nectaries are clavate, while otherwise it is similar to Aphis, plac- ing with it but three species; failing, however, to discover the clavate character of the nectaries in a@vene, which occasionally exhibits this character but faintly, so as to make them appear cylindrical and was therefore still retained by him in the genus Aphis; whereas in the true genus Aphis the nectaries are always more or less distinctly tapering. According to my own observations, after the migrants had been transferred from apple and Crategus to grain and grasses, I have found a certain range of variation in the comparative length in the joints of the antenn, as well as in the nectaries of the progeny of the apple louse, the extreme forms of which may easily induce super- ficial students to consider them as distinct. Large series, however, of the various forms, more or less due to the season or abundance of food, have convinced me that all of them belong to but one species. Some of the most constant characters of this insect are the compara- tively small or minute terminal fork of the front wings, which fre- quently varies considerably in the same specimen; the more or less strongly pronounced tuberculation of joints three and four and fre- quently also the fifth joint of the antenne, and the clavate character of the nectaries, which frequently becomes rather pronounced. Observations thus far made tend to show that the species is biennial and that the progeny of the spring migrants from the apple subsist almost exclusively upon various grains and grasses until the fall of the second year, when a generation of return migrants makes its appearance. The earliest ones of these produce the sexual females, whereas the others, appearing several weeks later, are the true males, thus closing the cycle of existence of the species. These observations show also that the progeny of the migrants from the apple are rarely seen during the heated term, and that most of them station themselves close to the base of the plants; though I have, on one occasion, also found a colony of Siphocoryne avene, including the winged form, about the middle of August, on the leaves of Panicum sanguinale, in 8 which the characters above mentioned were still those of the genuine apple plant louse. This similarity was evidently due to the general dryness of grasses common during summer, whereas from September till winter and the following spring, grasses as well as grain became more succulent and nourishing, with the result that nectaries as well as antenne developed more rapidly as the season and growth of plants advanced. These organs reached their maximum development toward the end of June, after which a general retardation set in, until the sexupares or return migrants were almost identical with those found on the apple during the spring, though stray specimens may fre- quently be encountered during the season, which indicate an over- lapping of two different series. The annexed list is for the purpose of indicating the localities and plants on which the grain louse has thus far been observed: Apple (Pyrus malus), United States, April to June, and September to November. Pear (Pyrus communis), Washington, D, C., October and November. Hawthorn (Cratxgus coccinea, ete.), Washington, D. C., May and November; New- ark, Del., November. Quince (Cydonia vulgaris), Washington, D. C., May and Noyember; St. Louis, Mo., June. Plum (Prunus sp. ?), Washington, D. C., June; Richfield Springs, N. Y., May. Choke cherry (Padus virginiana), Oakwood, Nebr., October. Wild black cherry (Padus serotina), St. Louis, Mo., October. Dogwood (Cornus sp. ?), St. Louis, Mo., October; evidently accidental. Celery (Apewm graveoleus), Washington, D. C., November; with larvee. Tickseed (Coreopsis sp. ?) Brookings, 8S. Dak., September; with larvee. Shepherd’s-purse ( Capsella bursa-pastoris), Washington, D.C., November; probably accidental. Burdock (Lappa major), Washington, D. C., November; accidental. Wheat (Triticum vulgare), Washington, D. C., March to June; Pocomoke City, Md., April; Adonia, Va., April; Trenton, N. J., May; Massachusetts, November; Carroll, Ohio, October, November; Wooster, Ohio, January; Lafayette, Ind., June; Laporte, Ind., December; Sherman, Tex., April; Los Angeles, Cal., April; Cham- paign, Ill., November. i Rye (Secale cereale), Atlanta, Ga., April. Oat (Avena sativa), Washington, D. C., November; St. Louis, Mo., November. Meadow grass (Poa pratense), Washington, D. C., October to December Bluegrass (Poa compressa), Ashland, Nebr., October. . Timothy (Phleum pratense), Washington, D. C., August, November. Finger grass (Panicum singuinale), Washington, D. C., August, November. Orchard grass ( Dactylis glomerata), Richfield Springs, N. Y., October. Upright chess (Bromus racemosus), Washington, D. C., June. Rescue grass (Bromus unioloides), Washington, D. C., January, 1903: Thus far 22 plants are herewith recorded on which the species has veen observed, of which 8 are trees, 4 are weeds or herbs, and 9 grains or grasses. 9 Siphocoryne avene Fab. Aphis avene Fab., Entomologia Systematica, Vol. IV, p. 214, 1794. Aphis mali Fitch, First and Second Reports on the Noxious and Beneficial Insects of New York, p. 49, 1856. Aphis prunifolix Fitch, First and Second Reports on the Noxious and Beneficial Insects of New York, p. 122, 1856. Aphis avenx Fitch, Sixth Report of the Noxious and Beneficial Insects of New York, p. 91, 1856. Siphonophora avene Thomas (in part), Eighth Report, Noxious and Beneficial Insects of Illinois, p. 52, 1879. Aphis annux Oestl., Synopsis of the Aphididee of Minnesota, p. 66, 1887. Aphis fitchii Sanderson, Thirteenth Annual Report Delaware College, Agricultural Experiment Station, p. 137, 1901. DESCRIPTION OF THE SPECIES. Winter egg.—The hibernating or winter eggs are deposited during the months of October to December on the trunk and branches of the apple, pear, quince, haw- thorn, and plum, under loose bark, in cracks, depressions, in the crotches, and around the buds, where they remain dormant until the following spring. They are about 0.6"" in length, pitch black, and highly polished. In favorable years they become frequently so numerous as to cover entire branches, when they may be readily observed. Yet, notwithstanding the great number of eggs, the majority, through one cause or another, are destined to perish during the coming winter, when num- bers of them are washed >ff by rains, sleet, or snow. Stem-mother; first generation.—The young larvyee, hatching from these eggs, make their first appearance, according to the advancement of the season, from about the middle of March to the middle of April, at about the time that the buds commence to burst. They are at that time about 0.6™" in length, at first yellowish green, though changing within a few hours to a rather dark green; the head changes to dusky or almost black in front and the eyes to a dark brown. The legs are dusky, rather stout, and somewhat hairy. The antenne are short and four jointed, with the third and the spur of the fourth much the longest and subequal in length. The nectaries are very short and tuberculiform, while the rostrum reaches almost to the end of the body. Within about a month after hatching they reach maturity. The mature stem-mother measures about 1.4™™ in length, by almost one-half of it in diameter about the middle of the abdomen. They are now of a greenish-yellow color, with the medio-dorsal line dark green, while the head, the first three joints of the antennz, the greater part of the legs, the lateral border and incisures of the abdomen are rather pale. The remainder of the antennie, sometimes also the entire legs and tail, are dusky and the eyes brown, while the nectaries are still paler than the body, with the apex only dusky. All are covered with an extremely delicate, pruinous secretion, which is often almost invisible above, though generally more conspicuous on the under side of the body. The antenne are rather slender, about one-half the length of the body and five jointed; the third joint is much the longest and almost as long as the rest beyond it. The nectaries are quite slender, cylindrical or somewhat stouter at base, though frequently with a slight indication of becoming clavate toward the end, and with the apex more or less distinc*ly flaring; they reach generally to or beyond the end of the body and are about as long as the spur of the last antennal joint. The tail is elongate conical, about half the length of the nectaries, covered with minute points and provided with a few bristles each side. The last abdominal segment is semicircular, its edge lined with minute, acute teeth, and fringed with a series of bristles. 10 Second generation.—The majority of the progeny of these stem-mothers reach maturity during the first half of May, almost all of which acquire wings, to enable them to spread from tree to tree or from one locality to another, for the preservation of the species, as otherwise they are liable to extermination by various enemies, which gradually increase in numbers and species. The pupze measure about 1.8™" in length, and are of a more or less translucent, Fic. 1.—Siphocoryne avene Fab.: a, migratory female; b, sexual female; c, antenna of migratory female; d, side view of end of body of winged male; e, under side of end of body of male; /, under side of end of body of sexual female; all greatly enlarged (original). pale, greenish-yellow color, marked with three darker green stripes, which are linear on the thorax and much the broadest on the abdomen. The head, four basal joints of the antennze, the wing-pads, and nectaries are whitish, often with a greenish or yellowish tinge; frequently there is also a reddish or ferruginous patch near the inner base of the nectaries; the future ocelli are indicated by brownish spots. The 11 remaining joints of the antennee, the tarsi and tip of nectaries are blackish, the apex of the femora brownish or purplish, and the tibiz dusky toward the end. The antenne are six jointed, the third joint and the spur longest and subequal in length, each of them almost subequal to joints four and five combined. The nectaries are similar to those of the stem-mother, with traces of the future clavate character of the imago. Migratory female (fig. 1, a and ¢); second generation.—The winged form of this gen- eration is extremely active and may be observed at favorable times to swarm in considerable numbers, and, settling on the proper kind of trees, proceed at once to deposit their young ones. The head and thorax of these migrants are of a polished black, with the depressions or sutures of the thorax more or less distinctly greenish; the eyes are brown; the antenne, terminal two-thirds of the femora, apex of the tibiee, the tarsi, and nectaries are black. The abdomen is greenish yellow, marked with three or four black, lateral spots in front and one or two beyond the nectaries; the tail varies from dusky to black. The basal section of the femora and the tibie vary between green and yellowish green, whereas the median line and lateral margin of the abdomen are frequently dark green. The expanse of their wings is about 7™ and the length of the body 1.5 to 2™. The antennze are rather short and stout and reach to or somewhat beyond the middle of the body; in the length of the various joints there is more or less variation in different specimens and frequently in the same specimen; the third joint and the spur are longest and generally subequal in length, with the fourth next and the fifth shorter than either of them. Joint 3 is always strongly tuberculated, frequently also the fourth and sometimes also, more or less so, the fifth. The nectaries are of medium size or generally about as long as the fourth antennal joint; as a rule more or less, though sometimes distinctly clavate, with the bulge toward the end an” most conspicuous on the inner side; the apex is flaring. The tail is curved upward, rather less than half the length of the nectaries, elongate conical and rounded at the apex; its surface bears numerous minute points, while on each side of its terminal half are about three curved bristles; the last abdom- inal segment is similar to that of the stem-mother. The venation resembles that of Aphis; the stigma is elongate lanceolate and its vein arcuate, while the terminal fork of the third discoidal vein is smaller than usual, sometimes minute or even wanting in one wing or the other. The third generation is composed of both the apterous and the winged forms which reaches maturity about the middle of May, while the fourth generation, which has spread to various related trees or shrubs, makes its appearance about the middle of June; the last or fifth generation, which is usually small and scattered, may be observed from the middle of June till the early part of July, after which time all have disappeared, leaving the trees free of them until the middle of September, when the pupiferous females or return migrants again make their appearance and continue to do so until the middle of November, to restock the trees with sexual females, which it takes about a month to bring to maturity, by which time, or from about the middle of October, the winged males make their appearance, having in the intervening time attained maturity on grain or grasses, and continue to do so till the middle of November or, during favorable seasons, even later. The pupiferous females, or return migrants, are as a rule somewhat larger than the spring migrants; their expanse of wings ranges between 6 to 8"™™ and the length of their body between 1.5 to 2.4™™; the antennze are also somewhat longer, with the third joint usually much shorter than the spur, though joints three to five vary just as much in length and tuberculation, as well as in the size of the terminal fork, from the spring migrants. The general coloration of the body has also become quite vari- able. In some specimens the color is of a rather yellowish green with the lateral spots very distinct, whereas in others it is of a grayish-green or dusky shade, or sometimes almost black. All except the palest forms show a more or less distinct 12 bronzed reflection on the dorsum, the under side being generally paler and covered with a more or lees distinct pruinous secretion. Otherwise they are like the spring migrants. Sevual female.—The mature sexual females (fig. 1, b and /)) measure from 1.6 to 1.8™™ in length; they are oval and almost equally tapering toward each end. The antennee are short, about half the length of the body, and five-jointed, the spur being the longest, with the third joint somewhat shorter; all of the joints are plain. The nectaries are short, and do not reach to the end of the body; they are usually taper- ing, cylindrical, or rarely slightly clavate; the tail is still shorter, its basal half rather broad, with the sides parallel, while the terminal part is broadly triangular and covered with minute sharp points. The posterior tibize are more or less dis- tinctly inflated and provided with numerous circular, sensorial pores. The color of these sexual females varies more or less; some are of a pale, dirty orange, marked with irregular dusky spots, while others are still darker, spotted only along the sides; many are entirely of a greenish dusky color, often exhibiting in front of the nectaries a lateral row of small, oval, whitish spots; all are, however, provided with a reddish shading around the base of the nectaries. The eyes are brown, the anten- ne, legs, and tail dusky and the nectaries black. Each of them contains from two to four or five eggs. These females, either before or after copulation, forsake their position on the leaves or branches and commence to travel restlessly about, in order to select a secure spot for depositing their eggs, when, especially during warm days of October, every part of a tree may be seen covered with them, either in copula or engaged in depositing their eggs. Male.—The males (fig. 1, dand ¢) as arule are generally smaller than the migratory females; their expanse of wings ranges between 5.4 to 7™™ and the length of their body between 1.2 to 2". The general appearance of the male is very similar to that of the migratory female, though the abdomen is narrower and the last two segments more protruding. The general color ot the abdomen is either orange or greenish yellow, though frequently there is a more or less defined, dusky, median line, ter- minating, between the nectaries, in a dusky spot. The antennz are generally somewhat longer and stouter than in the migratory female; joints three and four more strongly and more densely tuberculated and the spur longer than joint three. The genital armature consists of two elongated, triangular lobes or claspers, rounded at the end and covered with erect hairs, between which projects a cylindrical sheath, containing the colorless and flexible organ, which frequently may be observed extruding in a hook-like fashion. Before maturity of the females the males rest motionless on the under side of the leaves from which they draw their nourishment, though no sooner haye the females cast their last skin than they become very nervous and restless and walk briskly about on the branches and the trunk on which the females have congregated, so that frequently thousands of both sexes may be observed, among them many in copula, and often several males may be seen paying attention to the same female. All of those destined to produce a sexual generation the following fall remain and multiply on grains and grasses, though producing at certain times a migratory form to enable them to spread and to protect themselves against destruction over a large area of the country, during which time for a greater or less extent certain external changes take place, the extreme forms of which may easily pass as distinct species, when toward the second fall they return again to the original form. NATURAL ENEMIES AND PARASITES. Fitch, in his admirable work on the apple louse, refers to the larye of various aphis lions (Chrysopa) and ladybirds (Coccinellidee) as being very effective in keeping the aphides in check, whereas in con- 13 nection with the grain aphis he mentions the following parasitic or predaceous insects. Towares triticaphis Fitch; Praon avenaphis Fitch; Allotria triticé Fitch, and Adlotria avene Fitch. Of the Coccinellide he mentions Tippodamia parenthesis Say; Coccinella 5-notatu Kirby, and Coccinella 9-notuta Hbst. The only species bred by me from the grain aphis thus far, though in considerable numbers, is Aphidius nigriceps Ashmead. There were also bred by me a number of specimens of Syrphus americanus Wied., the larve of which prey voraciously upon the lice. The following original specimens, preserved by Fitch and bearing his identical numbers and names, as found in his notes, are: 4987, var. pallidicornis; 4988, triseriata; 4990, obsoleta; 4992, bicincta,; 4998, nigricollis; 4994, tergata; 4995, thoracica, 4997, nigriventris,; 5000, Julviventris, and 4991, without a name attached, which is probably identical with his variety ¢mmaculata. None of the following num- bers of A. ma//, mentioned in his notes, were found: 1125, 1126, 4987, 5004, 5548, 5549, 11603 and 11604, ¢, 11605 and 11606, 9, nor 11844-11853. One specimen, a male, marked by Fitch with the printed number 839, is preserved in the State Cabinet of Natural His- tory of New York, at Albany, N. Y. Of Aphis prunifolix Fitch, the following specimens, mentioned in his notes, are still preserved: a, d, e, 7, g; while 0, c, 4, and numbers 3772-3783 are lost. Of Aphis avence Fitch, but three specimens were found; two speci- mens bore No. 15237 and the other one 15238, while 15239 is lost. THE ENGLISH GRAIN LOUSE. (Macrosiphum granaria Bauckton.—Fig. 2.) Siphonophora Koch, Pflanzenliiuse, p. 150, 1857. Macrosiphum Baabamen: Gli Afidi, p. 27, 1860. Nectarophora Oestlaund, Aphididze of Minnesota, p. 78, 1887. In accordance with ‘priority, the generic term Siphonophora, as adopted by Koch, had already been preoccupied by Eschscholtz and described by him in ‘Syst. d. Acaleph.” in 1829, though, without knowing this fact, it was again applied by Brandt, ‘* Bull. Acad. St. Petersburg,” in 1836, for a genus belonging to the Myriapoda. Oest- lund, recognizing the ene of Siphonophora, substituted for it ieshulale of Minnesota, p. 78, 1887) the name Nectarophora, over- looking the fact that ee was antedated by Macrosiphum Fass. (Gli Afidi, p. 27, 1860), a generic term, unfortunately, adopted by Oestlund for a species with long and clavate nectaries, found on Rubus strigosus, which he named Macrosiphum rubicola, « generic term also adopted by Del Guercio (Afidafauna Italica, pp. 144 and 14 159) for a number of species agreeing with the characters of Macro- siphum Oestlund, overlooking, however, the fact that Macrosiphum was preoccupied by Passerini for a genus structurally quite differ- ent. Dr. M. H. Schoutenden was the first to observe this error, and changed Macrosiphum QOest/und to Nectarosiphon, in contradistinction to Macrosiphum Lasseriné. The principal characters of this genus, as accepted by authors, are: GeENus MacrostepHum Passerini. Front of head deeply concave, provided with large, terminally diverging frontal tubercles or projections for supports of the antennee. Antenne long and filiform, as long or usually much longer than to the end of the body or tail, with the spur of the sixth joint very long and bristle-like. Nectaries very long, cylindrical, tapering, and frequently projecting beyond the tail. Tail long, slender, more or less distinctly contracted near its base, curved upward. Legs long and slender. Wings large, the third discoidal vein with two forks; stigma rather long, narrow, elongate lanceolate. The majority of the species are large and frequent the foliage of weeds, cultivated plants, and grasses. Macrosiphum granaria Buckton. Siphonophora granaria Buckton, Monogr. of British Aphides, vol. 1, p. 114, 1876. Siphonophora avene Thomas (in part), Eighth Rept. Nox. and Benef. Insects of Il., p. 51, 1879. With regard to this species much uncertainty has existed. Buck- ton was the first to introduce this name in his writings on English Aphides, on the supposition that the insect in his hands at the time was identical with that treated of by Kirby and Curtis under the name of Aphis granaria, concluding also that A. avene Fab., hordec Kyber, cerealis Kalt., and Siph. cerealis Koch were all of them the same species. After examining, however, the extremely short and in every detail insufficient description of A. granaria by Kirby (Linn. Soc., 4, p. 238, 1798), I doubt very much that the species mentioned by Kirby and Curtis under the above name is identical with the one described by Buckton, but believe that the species treated of by them was the gen- uine Aphis avenxe Fab., and, while investigating this matter, found that a description of A. horde? was never published and that the name of it was simply suggested by Kyber (Germar’s Mag. d. Entomologie, vol. 1, pt. 2, p. 11, 1815), with a footnote to the effect that he intended to describe the species later on. It was surely not identical with A. cerealis Kalt. and Koch, which I have known for some years to exist in this country. Buckton, while describing his granaria, seems to have mainly depended on the superficial description of the species by Curtis (Farm Insects, pp. 287-290, figs. 9, 10, 11, and Pl. J, figs. 10, 11, 13, 1860, the figures of which are absolutely unreliable). As faras the description of avene is concerned, I am confident that it does not belong to Siphonophora A’och, since the frontal tubercles so characteristic of Siphonophora are wanting. Curtis states that the 15 antennex are inserted in front of the face, close to the inner margin of the eyes, which character alone would remove it from Siphonophora and bring it nearer to genera with rudimentary frontal tubercles, more or less closely related to Aphis. I should, therefore, not be surprised if future studies should disclose the fact that the species described by Curtis isidentical with Siphocoryne (Aphis) avene Fab. Buckton was apparently misled by the colored figure of a migrant on Pl. J, on which a number of spots on the abdomen are represented which have not been mentioned in the description, which plainly indicates that he described. one and figured quite a different species found on grain at the same time. At any rate, the first substantial description and illus- tration of the present species must be credited to Buckton. As to the Siphonophora avene, as described by Thomas, in which he includes granaria, cerealis, and hordei, I will say that he is very much mistaken. On page 52, and partly on page 53 of his report, Thomas simply reproduces the description of the true Siphocoryne (Aphis) avenx, as described by Fitch in his sixth report (p. 95, ete.), which he considered, without « doubt, as being identical with a species found by him on grain, whereas his description of the insect (p. 53) tallies well with Siphonophora granaria as described by Buckton. Until quite recently I considered the species treated of by Thomas as being identical with A. wvene Fab., until a careful examination of specimens found by me on oats at Stettin, Prussia, July 26, 1898, con- vinced me that the species found then was identical with the one described by Buckton and agreeing also with the short description of avene Thomas (Eighth Report Nox. and Benef. Insects of IIl., p. 53, 1879), though not with the species described by Fitch under the name of A. avene. Prior to that date and since then the same species had been received by the Department from Concord, N. C.—May 25, 1882, found infest- ing the ears of wheat. During December, 1888, it was found on wheat at Lafayette, Ind. In 1889 it was found on wheat at Washing- ton, D. C., and during August of the same year at Lafayette, Ind., on oats. In June, 1897, it was found on wheat and grass at Washing- _ ton, D. C., and in May, 1898, on wild rye (Hlymus virginicus) growing in Virginia near the shore of the Potomac. During themonth of June, 1900, it was found at Milford, Del., on wheat and rye, and in various localities in Kansas, where it sometimes proved to. be very abundant and destructive to wheat and oats, and on heads of wheat at Macomb, Ill.; it was also reported as doing much damage to wheat at North- ville, N. Dak. During April and May of 1901 it was reported as doing much damage to wheat from Adonia, Farmville, Shirley, and Spring Garden, Va., while, lastly, it was found to be very numerous on young volunteer wheat in the District of Columbia. 16 The list of grains and grasses on which it has thus far been observed is rather small, though there can be no doubt that it will eventually be found to subsist on many other grasses and possibly also on some weeds or other cultivated plants. That it must have existed in this country for a considerable Jength of time seems evident from the fact that its distribution has spread from Virginia to North Dakota, and that it will gradually be found in all the intervening States both north and south, as well as in the Western States or wherever wheat or other grains are grown, where — occasionally it may prove a serious pest. b Fig. 2.—Macrosiphum granaria Buckton: a, migratory female; b, third antennal joint of same, all greatly enlarged (original). DESCRIPTION OF THE SPECIES. Apterous female.—Length 2.4 to 2.8™™"; fusiform, broadest near the base of the abdomen. Frontal tubercles large, diverging at the apex, as usual, in this genus; ~ antennze bristle-shaped, as long or slightly longer than the abdomen; joint six, including the spur, longer than joint three; generally there are one or two small, circular and projecting sensoria near the base of the third joint; all of the joints are very sparsely beset with short and stiff bristles which are rarely slightly clavate. The 17 nectaries are long and reach beyond the tip of the abdomen, though rarely beyond the tip of the tail; they are cylindrical, tapering, becoming again slightly stouter toward the end. The tail is rather long and stout, curved upward, and about two- thirds the length of the nectaries, lanceolate, and more or less distinctly constricted about the middle; it is densely covered with acute, minute points and furnished each side of its terminal half with three, backward-curved, long bristles. The legs are long and provided with short, stiff, and simple hairs. The color of the apterous female is yellowish-green, often slightly pruinose; fre- quently darker toward the end of the body; the head yarying from yellow to brownish-yellow. The eyes are red to brown, while the tail varies from white to a distinct yellow. The antenne, as a rule, are black, though sometimes the first joint may be yellow or the first three joints dusky. The terminal half or more of the femora, apex of the tibie, the tarsi, and the nectaries brown to black; the rest of the leg is yellow. The body is frequently marked with a brownish puncture or spot each side of the prothorax; sometimes there is a narrow dusky or black line, composed of minute spots, each side of the mesothorax and a dorso-lateral row of about five linear or rounded, blackish or dusky spots each side of the abdomen, which sometimes are extremely faint or even wanting. Occasionally there are also two additional small black or dusky spots between the nectaries. Lateral spots in _front of nectaries black. Winged migrant.—Expanse of wings 9 to 9.4™™,; length of body 1.4 to 2.6™™, Antennze long, generally about one-third longer than the body; the third joint about one-third shorter than the sixth and provided along its exterior or posterior edge with-from six to eleyen more or less elevated, round sensoria along its basal third. The hairs of the yarious joints are similar to those of the apterous female, though sometimes one or the other may be distinctly clavate. The nectaries, tail, and legs in general appearance and size are very similar to those of the apterous form. The wings are almost twice the length of the body, while the vei.ion corresponds very niuch to that of Aphis. Color yellowish-green to green; the mesothorax yellow and its lobes brown to black. Sometimes a small, oblique, dusky, subdorsal spot and a transverse pale- dusky band may be observed on the prothorax. Head brown or brownish-yellow; eyes red to. brown. Antenne black, the first joint sometimes brownish-yellow externally. Nectaries black, the tail yellowish or greenish-yellow; sternal plate and lateral spot in front of wings black. The abdomen is marked with four or five small, transverse, blackish dorso-lateral spots and four black lateral spots in front of nec- taries; the coloration of the legs is similar to that of the apterous female. Wings clear, the costa dusky, and the subcosta yellow; stigma yellowish, its inner margin dusky; veins yellowish-brown, changing to black toward the end. In order to distinguish this species, besides the maculations of the abdomen, from near related species infesting grains and grasses, I have adopted the rule of measuring the comparative length of the antennal joints, the nectaries, and the last fork of the wings by tenths, with the accompanying result of variation: Joint 3, variation between 19 and 29. Joint 4, variation between 13 and 20. Joint 5, variation between 11 and 17. Joint 6, variation between 24 and 34. Nectaries, variation between 11 and 16. Last fork, variation between 22 and 36. The sexual generation or the eggs have thus far not been observed, 22104—No. 44—04—_2 18 Of their natural enemies or parasites none have been observed, though there can be no doubt that various species of ladybirds as well as the larve of Chrysopids and Syrphids will prey upon them when- ever they become sufliciently numerous to attract their attention. THE GERMAN GRAIN LOUSE. (Macrosiphum cerealis Kalt.—Fig. 3.) Aphis cerealis Kalt., Monog. d. Pflanzenlause, p. 16, 1843. Siphonophora cerealis Koch, Pflanzenliuse, p. 86, 1857. This species was first described by Dr. J. H. Kaltenbach (Monogr. der Pflanzenliuse, p. 16, 1848). At the time he considered it as being identical with Aphis hordet Kyber, which, however, had never been described. As food plants the following grains and grasses are mentioned by him: Wheat (Zrticwm sativum), rye (Secale cereale), oat (Avena fatua and strégosa), barley (Llordeum murinum), chess (Bromus mollis and secalinus), orchard grass (Dactylis glomerata), velvet grass (L/olcus lanatus), and meadow grass (Poa), feeding on the ears, the racemes, the petiole, and occasionally in small colonies on the leaves of grains and grasses, on the former of which, during July and August, they may frequently be observed in enormous numbers. Buckton (Monog. of Brit. Aphides, vol. 1, p. 114, 1876), as well as Thomas (Eighth Rept. Nox. and Benef. Insects of Ill., p. 51, 1879), make it a synonym of granaria, and the latter author considers it also a synonym of Aphis avene Fab., neither of them recognizing, how- ever, the characters by which it may be separated from either of them; since then, nobody, at least in this country, appears to have taken the trouble to separate the species referred to, notwithstanding that the range of this species appears to be as large as that of the other grain- inhabiting Aphides. That both granaria and cerealis are likely to be considered as but one species is very obvious, since both are of about the same size and coloration and may frequently be found intermingled on the same plant, though the maculation of the abdomen of granaria is absent in cerealis, in which the antennal joints and the nectaries are also con- stantly shorter. Divided by tenths, the following variations in these organs will be observed in the present species: Antennal joint 3 varies between 18 and 27. Antennal joint 4 varies between 13 and 21. Antennal joint 5 varies between 11 and 17. Antennal joint 6 varies between 24 and 37. Nectaries vary between 10 and 18. Last fork varies between 13 and 22. The above table, compared with that of granaria, shows that, as a rule, all of the measured parts are shorter than those of the species treated of before. 19 Specimens of this species were first discovered in small numbers in June, 1884, on wheat at Cabin John Bridge, Md., while during the same month, after harvesting of the wheat, it was found by me to be quite plentiful on rye and oat near Washington, D. C., and among them many of the winged insects, mainly stationed on the petioles and green seed capsules, which had become more or less discolored on that account. Whereas the majority of larve were found on the under side of the leaves, none were observed on the stems or roots. At the same time and in the same field they were also found infesting the ears and leaves of Agrostis vulgaris, Bromus secalinus, and Dactylis glo- merata growing between or near the grain. During September of 1884 migratory females found on wheat were received from Oxford, Ind. As an illustration of how far certain species of aphides may be dis- tributed by currents of air, it may be worth while to mention the fact that a number of migrants of this species were dipped up from the surface of the Alantic Ocean 94 statute miles from the nearest land, in the neighborhood of Nova Scotia, July 3, 1887, by the Fish Commission steamer Grampus. During November of the same year the species was found breeding on oat at Washington, D.C. In May, 1889, it was found on oat at Paxton and on wheat at Pleasantville, Ind., while at the same time it was reported as being very plentiful on wheat at Shiloh call, Ill. During June of the same year it was reported as being very abundant, on wheat and oat at Glendale and Columbus, Ohio, and Vincennes, Ind., and from Selkirk, Mich., on wheat and rye, at which time it was also found to be very abundant on oat at Highlands, N. C. In August it was found on oat at Ottawa, Canada, and in October on clover growing among the dry stubble of wheat at Washington, D. C. In January, 1890, specimens were discovered on wheat in Indiana and at Liberty, Va., covering the plants and killing large numbers of them. In May of the same year they were found on rye at Landisburg, Pa., while from Trenton, Morristown, and Camden, N. J., the report came that they covered the wheat and rye and were doing much damage. During June of 1890 they were reported from Storrs, Conn., Lunenburg, Pa., New Harmony, Ind., Milton, Ky., and Larue, Ark., as ruining the wheat and oat crop. In June and July of 1891 the species was observed on wheat at Millville and McGregor, Iowa, and Nashville, Tenn. The species was also found in May of 1892 on wheat at Columbus, Ohio; in November on Setaria viridis at Washington, D. C.; in June and July of 1894 on timothy and wild rye in Virginia, opposite Washington, and in September on the ears of oat at Shelton, Mont. Lastly, they were reported as doing much damage to the ears of wheat from Brookings, S$. Dak., since which time nothing has been heard of the species from any locality. The food plants on which, thus far, it has been observed in this country are: 20 Wheat (Zriticum vulgare), vye (Secale cereale), wild rye (Elymus virginicus), oat (Avena sativa), meadow grass (oa pratense), green foxtail (Setaria viridis), red top (Agrostis vulgaris), cheat (Bromus secalinus), orchard grass (Dactylis glomerata), and red clover (7rifolium pratense). Its range thus far has been found to cover most of the northern States, including Canada, east of the Mississippi, but having gradually spread beyond that border as far west as Montana and South Dakota, and may soon be expected to make its appearance along the Pacific slope. \ 3 ee - ‘a \ Fic. 3.—Macrosiphum cerealis Kalt.: migratory female; greatly enlarged (original). DESCRIPTION OF THE SPECIES. Apterous female.—Length of body 2 to 2.6™"; broadest about the middle of the abdomen, tapering gradually toward the head and more rapidly posteriorly. Antennz as long or slightly longer than the body; third joint shorter than the sixth and gen- erally provided near the base with one or twosmall, circular, and projecting sensoria; all of the hairs small and simple or but slightly clavate. The legs are long and their hairs short, stiff, and simple. The nectaries, as usual, are tapering and reach about to the end of the abdomen. Tail long, curved upward, and almost of the length of the nectaries; it is somewhat constricted about its basal third; its terminal section elongate lanceolate; the surface is densely covered with minute, acute spines and 21 each side provided with three backward-curyed bristles. General color a somewhat polished green with a yellowish tinge along the dorsum and with a few irregular darker green markings. The head is rather dark yellowand the antenn black with the two basal joints brownish or somewhat dusky. Eyes dark brown. Nectaries black, the tail dirty yellowish. Terminal half of femora black, the basal part pale greenish or yellowish; tibize dirty yellowish, their apex and the tarsi black. Winged migrant.—Length of body 2 to 2.4""; expanse of wings 7 to 8.2™™. Antennse longer than the body, reaching to or beyond the tip of the tail; joint 3 shorter than the sixth and provided with 4 to 12 circular and elevated sensoria along the basal half. Hairs minute, sparse,and simple. Nectaries as usual, reaching slightly beyond the end of the body, though not beyond the tip of the tail, and about one-third longer than the tail. Color of the abdomen green or yellowish green, the median line generally of a darker shade. Head light brown or pale dusky; eyes reddish to dark brown; ocelli clear, with the inner margin black. Prothorax greenish yellow and frequently marked each side with a dusky impression of three more or less distinct, dusky, longitudinal stripes. The mesothorax and metathorax are generally yellow, with the lobes, the sternal plate, and lateral spot in front of anterior wings brown or, rarely, black. Antennze and nectaries black, the two basal joints of the antenne sometimes dusky. Tail either colorless, pail greenish, or almost yellow. Legs yellow, the terminal third of the femora, apex of the tibize, and the tarsi black. Wings colorless, the subcosta and base of front wings yellow or greenish yellow. Stigma yellowish or pale dusky. Costa and veins brown to black. The sexual generation has not been observed. Of the enemies and parasites preying on this species which have been observed by the writer, the following may be mentioned: The true parasites, bred from this species are: Aphidius avenaphis Fitch and Aphidius obscuripes Ashm., Lygocerus niger Howard and Asaphes vulgaris Walker; while. the enemies observed to feed upon this plant-louse are the following ladybirds and their larve: JJeg7lla maculata DeG., Mippodamia convergens Guer., glacialis Fab., 13- punctata Linn., and Coccinella 9-notata Hbst.; also larve of the following Syrphus-flies: Syrphus americanus Wied., Xanthogramma emarginata Say, Allograpta obliqua Say, and Spherophoria cylindrica Say; specimens were also bred of two small Muscid flies, the larvee of which feed on the aphides, as Leucopis nigricornis KWeger and Leucopis simplex Loew. THE CLOVER PLANT-LOUSE. (Macrosiphum trifolii n. sp.—Fig. 4.) Specimens of this new species have been occasionally found at Washington, D. C., since the fall of 1889 until the summer of 1892, on wheat (Z7iticum vulgare); and on oats (Avena sativa), at Wooster, Ohio, which, at the time, on account of their food plant and general appearance, I considered to be but a variation of the (so-called) Siphonophora avene Thomas. During July, 1892, I found it also feeding on the stems of red clover (7r7foliwm pratense), and during November of the same year on the petioles and leaves of strawberries, 22 at which time I concluded them to be different from the other grain lice though possibly related to, but quite different from, Siphonophora fragariex Koch. The following year it was again found on straw- berries during November at Washington and very numerous in June, 1894, on the stems of red clover and on the stems of the common sow- thistle (Sonchus oleraceus). During the same month this species was also observed to be very common on red clover at Cadet, Mo., and on the leaves of dandelion (Zarawacum dens-leonis) at Washington. In Fig. 4.—Macerosiphwn trifolii Perg., n. sp.: migratory female; much enlarged (original). I * , April, 1900, it was reported as being very numerous on red clover at Charlottesville, Va., and in June on oat at Wooster, Ohio. While investigating the specimens found on strawberries it occurred to'me that they might possibly be identical with the species briefly. described by Riley, under the name of Siphonophora fragarie, var. immaculata, in the Rural World, for December, 1875, found on this plant at Kansas City, Mo.; but, after an examination of the few poorly preserved specimens, I found them to be different, and, since 23 it does not agree with any of the green species known to me, I have concluded to describe it as new, particularly as it may occasionally prove to become very injurious to grain. DESCRIPTION OF THE SPECIES. Apterous female.—Length of body 2.4 to 3™™. Antenne slender, reaching to or beyond the tip of the tail; third joint shorter than the sixth, provided with one to three -small circular and elevated sensoria; hairs minute, sparse, and simple. Nectaries very long and slender and longer than the third antennal joint; much thinner at the apex than at the base, curved upward and reaching to or beyond the tip of the tail; tail long, tapering, more than half the length of the nectaries, densely spiny, and provided each side with four backward-curyed hairs. Color, green or yellowish green, and frequently slighly pruinous, most densely so on the head and incisures of the body beneath, giving these parts a whitish cast; the median line of the body is generally of a darker green. The eyes are brown. The antenne of the fully mature specimens are black, with the two basal joints more or less distinctly yellowish; in younger specimens they appear yellowish, with the apex of joints three to five and the last one black. The nectaries are usually yellowish or slightly dusky, changing to black toward the apex and greenish toward the base. Tail pale greenish or yellowish. Legs pale brownish-yellow, base of femora greenish; apex of tibize and the tarsi black. Migratory female.—Length of body 2 to 2.4 ™; expanse of wings 8.4 to 9™™. Antenne slender and much longer than the body, the third joint much shorter than the sixth; the sensoria of the third joint are much more numerous than in that of the other two species found on grain, covering about three-fourths of the posterior edge of its base and ranging between 13 and 18 0rmore. The hairs of the antenn are also longer and generally simple, though sometimes also faintly clavate. The nec- taries are very long and slender, but slightly stoutest at base, reaching far beyond the tip of the tail and at least as long as the third antennal joint. The tail is of the same shape as usual in this genus and but slightly over one-third the length of the nectaries, usually densely covered with minute sharp spines and bordered each side by four slender bristles. The venation of the wings is as usual, though the.terminal fork is longer than in the other two species. The general color is yellowish-green, the median line of the abdomen darker, though many of the spots wanting. The head and thoracic lobes are yellow or brownish-yellow. Eyes brown to black; ocelli clear, bordered with black. Antenne black, the two basal joints and base of the third either green, brownish-yellow or dusky. Occasionally there arestwo black spots at the posterior edge of the metathorax and a black border on the scutellum. Femora green on basal half or more, changing gradually to yellow, brown and black toward the apex; tibize brownish yellow with base and apex black. Nectaries dusky to black and greenish at base. Tail green or slightly dusky. . Wings colorless, their base and subcosta faintly greenish. Stigma pale grayish-green, the veins black. Variations by tenths of the comparative length of the antennal joints, ete., are as follows: Joint 3, 28 to 35. Joint 4, 23 to 30. Joint 5, 21 to 25. Joint 6, 38 to 43. Nectaries, 28 to 31. Third fork, 22 to 32. Compared with the other two species it will be seen that the propor- tions of these organs are much the largest, those of cereals being the smallest. The sexual generation or their enemies have not been observed. 24 THE CHESTNUT WEEVILS, WITH NOTES ON OTHER NUT-FEEDING SPECIES. By F. H. Carrrenpen. INTRODUCTORY. The public is quite familiar, and disagreeably so, with ‘‘ wormy ” chestnuts. The grower who depends on the cultivation of chestnuts for a livelihood, or a portion thereof, knows ‘‘ how the worm gets in the nut,” and if he be a good observer he knows that it develops froma minute egg deposited by a long-legged, yellow or ochre-colored weevil, with a fine, slender snout longer than the body. From eggs so or deposited hatch the disgusting ‘* worms.” Thus much is known to the chestnut grower; also to many it is known that there are at least two species of the weevil. It was not until the year 1890 that any exten- sive work was undertaken to determine the life habits of the various species which are concerned in injury to chestnuts, hazelnuts, hickory nuts,andacorns. Inthat year Dr. John Hamilton“ eight-page account of the habits of our best- known species, eight in number.” The economic side of the question has received considerable notice in articles by Messrs. Gerald MeCarthy,¢J. B. Smith,“ and J. A. Lintner.¢ The article by the first-mentioned author is of considerable value, as it contains extracts from experienced growers of chestnuts, fifteen persons in all; and that of the last writer is especially useful because of the full bibliography presented. For many years, and particularly within the past three, numerous complaints have been made of damage by these pests, and frequent appeals for better means of controlling them are made. ; The larvee, grubs, or ** worms” as they are more commonly called, develop with the nuts so that those which first attain maturity are ready to leave the nuts nearly as soon as gathered. Others remain Fig. 5.—Chestnuts showing exit holes of chestnut weevil lary, enlarged one-fourth (origina]). “Balaninus: Its Food Habits, Can. Entom. (Vol. XXII, pp. 1-8). » Nine or ten other species have been described, but we know little of their habits, and they therefore need not be considered in the present article. (See Capt. T. L. Casey, Annals New York Acad. Sciences, Vol. IX, 1897, pp. 655-664.) ¢ Bul. 105, N. C. Agr. Expt. Sta., 1894, pp. 267-272. . d Rept. N. J. Agr. Expt. Sta., 1895 (1894), pp. 481-485. Twelfth Rept. N. Y. St. Ent. 1896 (1897), pp. 267-272. It should be mentioned, that certain notes by the writer (Ent. Amer., Vol. VI, p. 172) were not included. published an excellent - a F 25 until long afterwards, and not infrequently it happens that when nuts are stored in barrels, boxes, or similar receptacles, some nuts which were apparently sound when placed therein, are found with one or more holes in their shells, while the disgusting grubs can be seen in great numbers at the bottoms of the receptacles. The size of the exit holes varies from one-sixteenth to one-eighth inch, the smallest ones doubtless being made by a single larva of the smaller species of weevil, and the larger by the larger weevil, or perhaps by several of the smaller species. Injury varies according to the number of larve present and the size of the nut, as will presently be more fully explained (see fio. 5.) During comparatively recent years the culture of chestnuts has assumed considerable proportions, especially in the States of Pennsyl- vania, New Jersey, Maryland, and Delaware, and has taken a new impetus since the extensive introduction and development of Japanese and European varieties. These are grafted on American seedlings or native stocks, and thus many nearly valueless trees on equally unprom- ising soil are converted into sources of profit greater by far than if the same land were planted with other crops which could be grown. In short, were it not for the ‘‘ worms” and ‘‘ blights,” chestnut grow- ing might develop into a most profitable industry in regions adapted to it. RECENT INJURIES. During 1903 we received, among other reports of losses by nut weevils, two from Mount Joy, Pa., which are in brief as follows: April 20 it was reported that chestnuts were grown very exten- sively in that vicinity, one firm having as many as 800 acres under cultivation. The chinquapin weevil was known to our informant, who identified it among others of its genus, but subsequently it was learned by the receipt of specimens that the chestnut weevil was also present. He noticed that they appeared about the middle of July, remaining in the orchards until the first of September. He calculated that usually one in every four nuts was infested, and observed as many as thirty young grubs in single large nuts of the Paragon variety. In November our second correspondent corroborated the above statements, reporting that one firm had recently lost from 15 to 20 per cent of their chestnut crop of 800 acres from the ravages of weevils. From 75,000 to 80,000 grafts were growing there. Paragon nuts containing both forms of weevils were received, with report that from forty to fifty grubs were found in one nut, indicating the aston- ishing prevalence of the insects in that region. In such nuts every bit of meat was consumed, and some of the weaker weevils were starved. In the smaller nuts, one or two worms to a nut was the rule. Native nuts adjoining the orchard under cultivation were admitted to be neglected. 26 ESTIMATES OF LOSSES. A fair estimate of the total damage done annually by weevils to chestnuts grown for market in all portions of the United States would probably fall little short of 20 or 25 per cent, while in some years the percentage would exceed that, running as high as 40 or 50 per cent. Growers in some localities report no damage, others place their loss as low as 5 or 10 per cent, while instances are cited of whole crops being destroyed. A loss of 10 per cent, as with many other crops, although existent, is frequently passed over unnoticed. The amount of loss is dependent on locality, season, and to a certain extent perhaps on the variety of chestnuts grown. The greatest damage is usually incurred in regions where chestnuts have grown wild for many years, and the least in localities where there are no wild chestnuts or chinquapins and the nuts are grown only for market and carefully gathered. The greatest damage, from available sources of informa- tion, appears to be done in Massachusetts, Pennsylvania, New Jersey, New York (in the vicinity of New York City), Delaware, Maryland, Virginia, Tennessee, and North Carolina. In Georgia Spanish and Japanese varieties have been cultivated for years without attack by weevils being noticed. In New Jersey 50 per cent of the same varieties have been ruined. One grower in Missouri has reported no damage to 50 trees of an American variety about 18 years old, while another, at South Haven, Mich., has reported no injury for a period of three or four years to Japanese and Spanish chestnuts grown there, while from 5 to 20 per cent of the crop of native chestnuts was annually destroyed. The same correspondent reports having received 4 pounds of chinquapins from Tennessee, all infested. A Delaware grower has reported every nut on a single tree completely destroyed by the ‘* worms,” and Dr. J. B. Smith the nearly complete destruction of the chestnut crop of New Jersey for 1893. THE SPECIES OF CHESTNUT WEEVILS. The weevils which we know to depredate on chestnuts are two in number, the chinquapin weevil, Balaninus proboscideus Fab., and the chestnut weevil, 2. rectus Say. Like all other species of the genus they have extremely long, slender beaks or snouts, nearly as fine as a horsehair, and in these species considerably longer than the body in the female. By means of this long snout the female is able to penetrate the thick burr of the chestnut with its long spines and to cut out with the minute and sharp mandibles at the tip a little hole for the deposi- tion of her eggs. These are deposited, by means of a long ovipositor, through the husk, to the growing nut. The two species resemble each other greatly in color and in markings, the general color of both being golden yellow above (generally described as ochraceous or even clay OY yellow), and a little paler on the lower surface. The disk of the thorax is dark brown, with a wide bright band each side, and the elytra are ornamented with rich brown markings of variable size and extent. THE CHINQUAPIN WEEVIL. (Balaninus proboscideus Fab. ) The chinquapin weevil or larger chestnut weevil (fig. 6) is consider- ably the larger and more robust, while the female rostrum or snout, although proportionately of about the same length, is a little more prominent because less curved, the curvature being toward the tip, and more widened at the base. The first joint of the antenna proper (omitting the scape or long joint nearest the head) is shorter than the second, and the mesosternum is less convex. The body measures from one-third to nearly one-half of an inch in length, and the snout of the female is some- times five-eighths of an inch long. That of the male is nearly as long as the elytra. Occasional individuals lack the darker markings, some being paler while others are darker, even reddish. The ground color, as may be seen inabraded specimens, is really black, and the color is due to scales very similar to those of butterflies and moths. The egg of this species, or, for that matter, of the genus, Fig. 6.—Chinquapin weevil (Balaninus proboscideus): a, female beetle; b, same in outline from Stde; c, head, rostrum and antenna of male, three times natural size (original). has apparently escaped observation, since no description has been made of it. The larva of proboscideus (fig. 7, a) is slightly different from the normal curculionid in form. Itis milk white, robust, fully three times as long as wide, the upper surface rounded and convex; the sides are somewhat flattened, and the lower surface is much flattened when the larva is at rest on a smooth surface. The entire surface is very strongly wrinkled transversely, and there are a very few short hairs scattered sparsely over the different segments. The spiracles are irregularly rounded and rather prominent. The head (fig. 7, 4) is nearly circular or slightly longer than wide, pale yellowish brown, marked with the usual inverted Y-spot, and the mouth parts are mostly black or very dark brown. The first thoracic segment has a narrow pale yellow cervical plate divided at the middle, and nearly twice as 28 wide as the head. The head is about one-fourth as wide as the widest portion of the body. The fully developed larva in ordinary resting position measures nearly half an inch, while extended it measures a full half inch. Although, like most Curculionide, the larva has no true legs, it crawls with comparative ease, though slowly, by means of the flattened ~ lower surface, being aided somewhat a by the transverse wrinkles. The hairs are so short as to be of little or no apparent assistance in locomotion. The pupa has not been seen by the writer. The occurrence of the chinquapin weevil has been noted at Providence, Bit iS Balninie probaeodenas larva anpoae, oes in the neighborhoed of New four times enlarged, at left; head much en- York City; Moorestown, Woodside, ogee eras Orange Mountains, N. J.; at State College, Allegheny, Jeannette, Mount Joy, Sylvania, Princetown, and Eastmont, Pa.; Newark, Del.; Baltimore, Md.; Virginia; West Vir- ginia; Washington, D. C.; Cincinnati and Newark, Ohio; Illinois; St. Louis, Mo.; Sharpstown, Ind.; Clarkville, Tenn., and Rosedale, Kans. THE CHESTNUT WEEVIL. (Balaninus rectus Say) The lesser chestnut weevil (fig. 8) has the scape of the antenna longer than in proboscideus and the first joint longer than the sec- ond. In the female the ros- trum is strongly curved, the thorax is longer than wide, and the elytra are strongly acuminate apically. The tooth with which the femora or thighs are armed is small, with the entering angle rounded. The average length of the body is about one-half of an inch, but : : Fic. 8.—Chestnut weeyil (Balaninus rectus): a, female the size varies, as in all of these — jeetle; b, same, lateral view; ¢, head, with rostram insects and antenna of male, four times natural size (origi- g : nal). The distribution of these two weevils does not differ markedly, but proboscideus appears to be some- what more abundant southward, while vectws is the more prevalent northern form. Where chestnut growing is an important industry the two species appear to be nearly equally numerous. The chestnut weevil occurs in Canada; Mount Tom and Marion and 29 elsewhere in Massachusetts; Penn Yan and Ithava, N. Y., and in the neighborhood of New York City, on Long Island and Staten {sland; and in neighboring portions of New Jersey, as also elsewhere through- out the latter State; Mount Joy, St. Vincent, Allegheny County, Pa.; North Carolina; Baltimore, Md.; Washington, D. C.; Pennington Gap and elsewhere in Virginia; French Creek, Harpers Ferry, Fort Pendleton, and Berkeley, W. Va.; Ohio; Retreat, N. C. The larva, as would be supposed, is much smaller than that of the chinquapin weevil, being only a third of an inch long and about a third as wide as long. The body is milk-white and the head light brownish yellow, the A-mark with a short lateral branch each side. TIME OF APPEARANCE OF THE TWO CHESTNUT SPECIES. Balaninus proboscideus, according to Hamilton’s observations, ap- pears at the time of the first blooming of chestnuts, and disappears when the blossoms have fallen. In his rearing experiments at Alle- gheny, Pa., the beetles began to issue June 25, and ceased July 12. Mr. Th. Pergande reared the beetles in the District of Columbia from August 10 to September 15. As 80 examples were reared by Hamilton and the mean temperature was nearly normal (although not so con- sidered by Hamilton himself), these dates are approximate for regions with a climate like that of Allegheny, Pa. Balaninus rectus was reared by Hamilton from June 28 till October 1, 95 examples having been under observation. This experience coincides somewhat closely with the writer's who has found this species in the field, although somewhat scatteringly, when chestnuts were in bloom, and reared specimens in captivity during the latter days of September which remained alive nearly a month. From present knowledge it is evident, therefore, that proboscideus might be somewhat more easily controlled than rectus, with its much longer active period. In most other respects the two species show very close agreement as to their life history. HIBERNATION. The chestnut weevils, as also all related species, so far as we know, hibernate exclusively in the larval condition and in the soil. This gives a larval period of at least ten months, and some individuals (reared in confinement, it is true, but under comparatively natural con- ditions) pass over till another year, this being the exception, but evidently a provision of nature for the continuance of the species. In such cases the larval condition lasts nearly two years. This has been noticed by Doctor Hamilton in the case of several species, and in our own rearing jars in the case of the smaller chestnut weevil, Balaninus rectus, 30 Larve pass the winter at varying depths, according to the soil and the degree of its hardness. In a large jar, full of moderately moist sand, in which chestnut ‘* worms” have been placed by the writer, the larvee have penetrated to a depth of 9% inches in a possible 10 inches. They make cells considerably larger than themselves, so that they have ample room to move about. The larger cells of proboscideus are half an inch long and about one-sixth of an inch in height. As arule, the larvee rest on their backs in a moderately curved position. Ordi- narily they remain in perfect quietude even in a moderately warm temperature, but respond to stimulus. FOOD HABITS OF SPECIES OF NUT WEEVILS. Of the eight species of nut weevils of the genus Balaninus known to inhabit America north of Mexico, the food habits are approxi- mately known, largely through the investigations of Dr. John Hamilton (Il. c.). The following summary is given of the observed host plants: Balaninus rectus Say, the common chestnut weevil, is nearly confined to chestnuts and chinquapins, having been reared only from these nuts, with the exception of a single lot (identified as this species ) which bred from acorns from Arizona. It appears to be the only species affecting chestnuts in the extreme northern portion of the United States where Balaninus occurs. Balaninus proboscideus Fab. (carya- trypes Boh.), the chinquapin weevil, depredates chiefly in chestnuts and is quite as great a pest as the preceding in some regions. It also breeds in (es : Fic. 9.—An acorn weevil, Balaninus victoriensis: a,fe- Chinquapin. male, dorsal view; b, same, lateral viéWr-e;-head of Balaninus quercus Horn affects in male, showing antenna and rostrum, four times ae about equal numbers acorns of differ- enlarged (original). ent species of biennial fruiting oaks, not being found in annuals (white and chestnut oaks). Mr. Fdk. Blanchard has reared this species from acorns of Quercus rubra, and the writer obtained many specimens from the same or a closely related species. Balaninus nasicus Say prefers the acorns of the annual fruiting oaks (white and chestnut), depredating snaringly on those of biennials. ; Balaninus carye Horn has been reared from pecans from Indiana, and has been found so abundantly on hickory as to leave no doubt that ‘‘wormy”’ hickory nuts are also due to the work of the same species. As a rule, however, it does much less injury to these nuts than do the others to acorns and chestnuts. Mr. Blanchard has also reared this species from shagbark hickory. Balaninus uniformis auct. prefers the acorns of biennials, but depredates occasion- ally on chestnut oak. In some localities, at least during certain seasons, as, for example, at Ithaca, N. Y., this species is the most abundant, while in western Penn- d1 sylvania Hamilton found it comparatively scarce. Possibly the variation in numbers may be seasonal. Balaninus victoriensis Chttn. n. sp.“is also an acorn weevil, having been collected in great numbers on oak by various collectors. Balaninus obtusus Blanch. has been reared from hazelnuts only (Hamilton, Can. Ent., vol. XXII, p. 6). In 1891 hazelnuts were reported badly injured by this species in Iowa (Alda M. Sharp, Bul. 17, Iowa Agl. Ex. Sta., p. 450). Balaninus confusor Ham. has been reared from the acorns of bear or scrub oak (Quercus nana ilicifolia), but it probably lives on the fruit of other oaks. Fig. 10.—Pecan nuts showing exit hole of pecan weevil larve, one-third enlarged (original). An interesting fact was brought out in the rearing of the last- mentioned species which has a bearing on the habits of the genus. A single individual was reared from a large apple oak on a species of golden rod (Solidago nemoralis), due to the larva of a two-winged fly, Acinia solidaginis Fitch (see Can. Entom. Vol. XXV, p. 310), showing the possibility of the different species developing on other than their normal food plants. In this case, as Hamilton remarks, oviposition on the gall was probably a mistake on the part of the parent beetle. Three of the larve were observed. It might be impossible for species with short snouts like the hazelnut weevil to oviposit in chestnuts on account of the thicker husk and longer spines, but, on the other hand, it might be possible for some other snecies to depredate on hazelnut in the event of absence of the normal uost plant. « Balaninus victoriensis n. sp. (fig. 9).—With a view to lessening the confusion which has existed with reference to the name of this species, which is generally known in collections as uniformis Lee. or obtusus Blanch., the writer presents a brief analysis which, together with the illustration, will more clearly define its identity: Body black or nearly so, covered with dense gray scale-like pubescence; elytra variously mottled with brown, slightly elevated, pubescent spots. Rostrum 9 four- fifths as long as body (including head), moderately, nearly uniformly arcuate. Anten- nal joints as figured, length a little shorter. Length, 7™™.; width, 3.5™". Habitat: Victoria and elsewhere in Texas. Related to wniformis Lec. from California, which is described as ‘‘densissime fulvo-pubescens, concolor,” etc. The latter is smaller. B. obtusus is much more robust and has a much shorter rostrum in °?. 32 THE HICKORY-NUT WEEVIL. ( Balaninus caryx Horn.) Nearly every year inquiry is made in regard to the cause of the holes in hickory and pecan nuts, but during 1903 there were reports of greater injury of this nature than ever before, more particularly to pecans grown in Texas, where considerable loss was reported by Mr. Glenn W. Herrick, and in Georgia, where Mr. Wilmon Newell stated that in one locality (Thomasville) 75 per cent of the crop was a failure. 4 m 0 (e) = m Be] op} ae) 3D i > < Zz ro) ope 5 Uv : > ee) > 7 4 Ee wn » - D cl o | FZ atop) > Z = [a9) em 2 wD Zz > a Gg z= Oo O ie) e 2 4 eS O > T eH Al Se ® be Hh i HH aa 4 my Ealestetepaepeyeney: Hea if wuts tf id ee o 2 Se a * ~ 2 Ss we ee oe. Rods i e ~ ‘ ® = - \" ; ' ¥ \ ‘ ‘ ’ 7 ; « el! 1 vA ‘ ‘ : i. wy a Vid oy ie 5 ¥ z - - i; + 28 “ 61 the leaves are off of the trees, and the same strength in winter on apple and cherry to kill the eggs of Bryobia. The writer witnessed the operation of two excellent power-spraying machines of the character above indicated, built under the direction of Mr. 8. A. Pease, for use in San Bernardino County. The work in hand was the spraying of some orange orchards of large trees for the yellow scale (Aspidiotus citrinus Coq.), and the apparatus worked remarkably well, and the results seem to be most satisfactory. In all, nearly 300 acres of orchards have been successfully treated by Mr. Pease. The following description of this apparatus (see Pl. I), of which the county of San Bernardino keeps three in operation, is supplied by Mr. Pease: The San Bernardino County power spray machine, built by Osler & Miner, Pomona, Cal., is designed to use either distillate spray or other mixture, and is equipped with a 2-horsepower Root & Van Dervoort engine, and a double-acting pump with 2-inch cylinders on each end, 10 inches long. The piston of the pump is driven backward and forward by use of bent shaft, with which a large cut gear is placed on the end, run by a pinion on engine shaft. The suction of the pump is taken from the bottom of the agitator tank and dis- charged into the air tank, which will withstand 300 pounds pressure. The power of the engine is sufficient to run up pressure of 300 pounds or more, and to run four lines of spray hose with two nozzles on each line, which will consume about 250 gallons of spray mixture in thirty minutes. The agitator tank is horizontal, holding 255 gallons, and has a shaft directly through center in which three sets of paddles are bolted, each being 4 inches in width. The paddles are placed on shaft at different places, and point in different directions. As the paddles revolve they throw the mixture in one direction. There are three lines of breakers placed on - the inside of the tank lengthwise, which throw the fluid back, making a double mixture. These paddles are operated by means of two sprocket wheels, one placed on end of the bent shaft at engine, and the other on the paddle shafting at the end of the tank, connected by chain. There is a small horizontal centrifugal pump run by belt.from the engine, which is used together with 25 feet of suction hose to pump water out of ditch or standpipe. By this means the agitator tank is filled in four or five minutes. The above appa- ratus is mounted on a platform over a set of iron trucks with 5-inch tires. ‘A pair of bolster springs are used which will carry a weight of 8,500 pounds. The methods of supervision of treatment of orchards in California are always instructive. In Los Angeles County there is direct super- vision of the work by the horticultural commissioners. The fumiga- tion or spraying is done by contractors, but with the provision that the work must be approved by the proper county official before pay- ment can be collected. At Riverside the work of this sort is done by the county directly, and a charge is made for actual cost, plus 10 per cent. A similar method is followed in San Bernardino County. 62 THREE BRITISH FRUIT-TREE PESTS LIABLE TO BE INTRODUCED WITH IMPORTED NURSERY STOCK. By Freperick V. THroBaup, Wyecourt, England. The subject of the importation of injurious insects from one country to another is a most important one. That many European pests have been imported into America and into the British colonies is well known. These unwelcome visitors, finding their new surroundings abnormally congenial and their natural enemies absent, often cause far more harm than they do at home. It is unnecessary to mention examples so well known to allinterested in economic entomology. The study of the insect pests of other countries than our ownis thus rendered very neces- sary, so that we may be prepared to fight and prevent the new arrivals. This distribution of noxious creatures is most important in regard to fruit and ornamental plants. The notes on three British fruit pests which may easily be introduced into America may therefore not be unwelcome to the members of this Association. The three pests that appear to me to be especially guarded againstand which I believe do not occur in the orchards and gardens of America are the following: The pith moth (Laverna atra); the apple sucker (Pysl/a mali); the currant-bud mite (Ariophyes ribis). All these pests occur permanently on trees or bushes in one or more of their stages, the winter in all cases being passed upon the plant, the pith moth in the larval stage, the psylla in the egg condition, and the currant bud mite in all stages. They can therefore be easily trans- ported on nursery stock. It may be said that the fumigation of the young plants or cuttings with hydrocyanic-acid gas will prevent their introduction, but from experiments I-have made I am confident that the ova of the psylla and the bud mites are not in the least harmed by the treatment, and I doubt if the effect of this gas would kill the larve of the pith moth in question. The apple sucker and the big-bud mite of the black current are both such serious pests that great caution should be exercised in importing stock from England and Europe. For the latter pest we have abso- lutely no remedy, and the former is most difficult to fight. THE PITH MOTH. (Laverna atra Haw.) Syn.: L. putripennella Zell. This small Tineid moth has long been known in Europe by ento- mologists, butit was not recognized asa pest in Great Britain previous to a short note made by Miss Ormerod in 1890; a few subsequent notes were added by her, but nothing of any special value or originality. 63 Previous valuable observations had been made, however, by Muhlig, of Frankfort on the Main (wde Kaltenbach’s Die Pflanzenfeinde aus der Klasse der Insekten, p. 781). During the past three years this insect has been very destructive in parts of England, notably in Sussex and Kent; observations have also been made in Gloucestershire and Mid- dlesex, and I have seen it working among the fruit trees in Cam- bridgeshire in 1889 and in Huntingdonshire on more than one occasion. Since the attention of the fruit growers has been called to this pest it has been noticed quite frequently. The damage done by the larva is very great, and as there is no known remedy, it is very important. to try and prevent its importation and to destroy it by drastic measures when it makes its appearance in an orchard. Miss Ormerod states“ that ‘‘the attack appears to be very seldom noticed with us in con- nection with apple injury.” This is not the case; it has been fre- quently noticed by growers, but the observations have not been recorded by them. This pest can easily be detected by its workings and the symptoms it produces; the red larvee, by tunneling into the buds and shoots (of all classes), cause the former to die off soon after opening and the shoots to at first flag, then wither up and eventually turn brown and die. In the first series of observations I made on this pest I found the termi- nal shoots only affected,’ but, as pointed out to me by Mr. Bear, of Hailsham, all shoots and buds suffer indiscriminately, and this has been frequently observed during the past year. The dying off of the young shoots has frequently been attributed by growers to canker (Nectria ditissima), which 1 have seen to produce very similar symp- toms. But by breaking open the bud or dead shoot, the true cause is soon seen by the presence of the small, red caterpillar or its brown pupa near the apex of the bud or shoot. So far I have found this insect only on dwarf trees, and reports sent me are all to the same effect. Twelve-year-old trees are the oldest I have at present detected these pests on. The fact that it is mainly on young stock has given rise to the idea in England that it has been imported. This is not so, for it not only occurs on the apple but is mentioned by Stainton? as being ‘‘not scarce. in June on white thorn.” Herr Muhlig also says that ‘‘the caterpillars live in the same way on the allied white thorn, which they more especially infest in this neighborhood (Aix la Cha- pelle).” Stainton seemed to doubt that the same species occurs on the whitethorn and the apple, for he says: ‘‘ The dark variety appears exclusively attached to the apple; it is possible it may be a distinct species.” I have found during the past year that those bred from the apple vary from the dark form mentioned by Stainton to the typical «Handbook of Orchard and Bush-Fruit Insects, p. 278. 1898. 6First Report on Economic Zoology, p. 68, 1903. ¢Lepidoptera Tineina, pp. 239 and 240. 64 shades seen in the whitethorn living specimens, and I am convinced that they are the same. LIFE HISTORY. The moth is slightly less than half an inch in wing expanse. The color is subject to much variation; the front wings are often almost entirely black, the posterior wings gray with gray fringes; other speci- mens have the front wings mottled with dark brown, brown, and rusty brown, and the inner margin of the fore wings is white to beyond the middle, where an irregular oblique white bar proceeds to the tip of the wing, and from this two branches may intersect the black apical portion; the head is almost entirely white. The white mark- ings are particularly variable. This insect occurs in June, according to Stainton,” but all those I have bred out appeared between the 12th of July and the 10th of August. The moths are very active, running with great energy, and frequently fall on their dorsal surface. They rest during the day on the twigs and stems and are then scarcely noticeable, owing to their color being similar to the rind. The egg stage has not been observed on the apple trees, but they are appar- ently laid soon after the moths have hatched out. I have found small lary on the leaves in September which I am sure were those of this moth; they reached one-twentieth of an inch in length. The next stage occurs under the bark of a twig, beneath which the small larvee have eaten their way; others bore into the base of the buds and there they remain all the winter. The hole of entry is so small it can only be detected by microscopic examination. During January and February the young larve were found tunneling into the pith of the shoots and also feeding at the base of the buds. In May their work in the pith is most pronounced, and later they work into the flower stalk and eventually the whole shoot, perhaps for 3 or 4 inches, dies away. I have found them in the stalk of fruitlets and many in the buds which never develop to maturity. The larve live until June; the majority pupate by the 20th, but some not until the last week of the month. The caterpillar is dull reddish brown with a deep-brown head and first segment; the other segments show more or less traces of pale-brown spots, four in a row on the second and third segments and four placed in a quadrangle on the remaining segments; the two anterior seg- ments have two lateral spots and the others one each; the apex is brown and the sucker feet rather paler. When matured they reach one-third of an inch and pupate near the apex of the shoot or bud. The pupa is bright-ochraceous brown with the head, front of thorax, and tip of the body mahogany red. On the ventral surface of the penultimate segment are two blunt processes, separate and widely diverging with hairy apices; the eyes are black and the wing cases «Manual of Butterflies and Moths, II, p. 399. ee 65 and leg cases long and pointed. The pupal stage I found varied between two and three weeks. Prior to the moth hatching the pupa frequently is forced half out of the dead bud or shoot. According to Stainton, the larve also occur in hawthorn berries in September; the black variety only in apple shoots in February and March. Recent observations, however, show that all variations in color breed from the apple, and probably the larve in hawthorn berries are of another species, for on the haw or white thorn Laverna atra works just as it does in the apple. Fortunately this insect attacks only small trees, and so can easily be destroyed by hand picking the dead buds and shoots before the moths escape. Where this has been done the pest has been kept under, and in some cases practically stamped out. Probably autumnal spraying with arsenites would kill the young larvee before or when they burrow into the rind of the shoots. THE APPLE SUCKER. (Psylla mali Schm. ) This apple pest causes great loss to fruit growers in this country, and has apparently increased very considerably during the past few years. It very much resembles your pear-tree psylla (Psylla pyricola), so ably dealt with by Slingerland.? This latter pest I have never detected doing any damage in England. The apple psylla which was recorded as a pest as long ago as 1837? has since been mentioned by the late Miss Ormerod in her reports, etc., in which the observations of fruit growers have been recorded, though but little fresh matter was added to Kollar’s original paper. This pest having become more serious during recent years, I have devoted two seasons to its study, which have brought to light many new facts in its economy. As it appears to me to be a very likely insect to be imported into America on nursery stock from Europe, I include this species with a hope that the notes may help my fellow-workers should it unfortunately make its way into America. The effect of this pest on the apple trees is very varied. The larve and pupa suck the juices of the buds and frequently check their growth entirely, the buds turning brown and dying; at other times they do not kill the buds, but damage them so far that the leaves, when they open, are crinkled and curled. Later they attack the open leaves and frequently the stalks of the leaves, which then die. The larve attack both leaf and blossom buds, but the latter are especially chosen, and a tree attacked by this pest seldom produces any fruit. The leafage that comes after an attack may be irreparably *@The Pear-tree Psylla. Bul. 44, Cornell University Experiment Station, 1892. >Insects Injurious to Gardeners, Farmers, etc., p. 270, (Trans. J. and M, Loudon. ) 22104—No. 44045 66 damaged, but I have during the past year seen it completely recover. This no doubt was due to the abnormally wet summer we have had. The winter is passed in the egg stage, chiefly on the young shoots, and thus it may be transported from one country to another very easily. LIFE HISTORY. The adult insects are about one-eighth of an inch in length and at first are pale apple green in color, but as the autumn advances they become varied in color, some reddish, some still green, others mottled with yellow, and others pale green with red or brown mark- ings; the wings are veined in the typical way and are transparent, and sometimes they are iridescent, the veins being pale yellow or green. The adults occur from July until even November and live on the leaf- age of the apple, where they frequently occur in little colonies, but they soon disperse if the tree is jarred, and move with that character- istic jump and flight common to this group. I have never noticed the adults doing any damage to the leaves, but Miss Ormerod states that ‘*they may be found in parties of five or six on a leaf, especially on a yellowing leaf,” which looks as if they may do some harm to the foli- age. Egg laying commences soon after pairing and may go on until as late as the end of November, but such is unusual. The females mainly deposit their eggs among the fine hairs of the young shoots, but they may be observed in cracks and crevices of bark. Generally several are laid together and then usually in rows, end to end. The eggs are roughly spindle shaped and white in color, and apparently have one end slightly prolonged, but not as in the pear psylla. As many as 20 or 30 may frequently be counted on a shoot. They remain in this condition all the winter, and I have found many are killed by an application of caustic alkali wash, and this probably fur- nishes a reason why the pest has not beén so harmful where the orchards were usually sprayed with this wash,“ and occurred in num- bers again when this useful orchard treatment was given up. As soon as the apple buds commence to swell in the spring, the larvee come from the eggs and soon work their way into the buds. If the buds develop rapidly the leaf and blossom come out and are only stunted; but if the nights are cold, and growth is retarded, they may be killed entirely. During the past year the larve were noticed in the opening buds early in May, and they were all in the pupal stage in the second week in June. The larve at firstare dirty yellow, with brown and dark spots upon them, the tarsi brown and the eyes red; in general form they are flat. After the first moult the larva protrudes a small white opaque globule, which remains attached by a white or pale blue thread. Soon after the second moult the larva becomes pale oo -- ~ «Second Report Economic Zoology, p- 50—F. V. T. wr esd Dey. 67 green, and there are formed by it a number of tangled white threads. In about another week a third moult leads to the pupal stage. In this the wing-buds are very prominent, and the tips of the antenne and the eyes become black. Like the larva, the pupa passes out the same oily globules and waxy white or blue threads. Those kept under observation on a tree hatched on the first of June, and they remained until the end of the month. The adults pass a monotonous life on the apple trees. I have also found great numbers of this pest in the winged stage by beating hawthorn hedges in the neighborhood of infested orchards. Trans. Amer. Entom. Soc., v. 21, 1894, p. 328. ¢ Bul, 6, n. s., Div. Entom., U. S. Dept., Agr., 1896, p. 73, 80 Hopkins stated that observations led him to believe that this fly was more destructive to growing red and crimson clover seed than the midge. He also noted that while the midge actually prevented the seed from forming, the chalcis-fly fed in the developing seed and allowed it to almost reach maturity before entirely devouring the seed content. The following year, at the next annual meeting of the same association,“ Dr. Hopkins reported that his studies of the year left no doubt ‘‘ of the chalcis-fly being a destructive enemy and that it wintered out of doors in the seed as a larva.” Lintner, in his report as State entomologist of New York, for 1896, credits the clover injuries reported by a correspondent of his office, “J. W. J., Muncie, Indiana,” to the clover-seed worm (rapholitha (Enarmonia) interstinctana Clem. The description of the injury as reported by the correspondent, ‘* seeds hulled out like beans eaten by bugs” would indicate the work of this chalcis-fly rather than that of the seed worm. LIFE HISTORY OF THE SALT-MARSH CATERPILLAR (ESTIGMENE ACRZA DRWU.) AT VICTORIA, TEX. By W. E. Hinps. While stationed at Victoria, in 1902, there were brought to the head- quarters of the boll-weevil investigations during the last part of July and first of August numerous reports of very serious damage to cer- tain fields of cotton which, it was said, were being entirely stripped of leaves by a very ‘‘large black caterpillar.” One of the remarkable ‘‘facts” reported in regard to this strange caterpillar was that ‘it could not be poisoned.” Nothing seemed effectual.in stopping the progress of the worms, and the foe was thought by some to be ** worse than the boll-weevil.”» As soon as the larve had stripped one field, it was said, they would move in vast numbers to fresh fields where they would repeat their work of devastation. So alarming were the reports and so urgent the appeals to the boll- weevil investigators, that on August 5an examination was made in the infected territory. It was found that the damage was being done by the larvee of Lstigmene (Leucarctia) acrea Dru., the *‘salt-marsh cater- pillar,” so called because at the time it was first described the larve were overrunning the salt marshes in the vicinity of Boston, Mass. The larve had nearly completed their feeding when found and a large part of them had crawled out of sight into favorable places for pupa- tion. The thin cocoons, made by interweaving the long hairs from the body with a light web of silk, were found at the surface of the ground under some sort of rubbish. Asa rule about one-half of the cell was fee as a ee to a corresponding depression in the earth. A large @Bul. Ly, ans ists Die Entom., U. 8, Dept. Agr., 1897, p. 45. Pat ee eee 7 81 number of caterpillars was taken to the laboratory, where they could be watched and the general facts of their life history determined. All the larvee spun up within five days after being taken from the field. The average length of the pupal stage was about two weeks, varying only a few days inany case. As the moths were found to be depositing eggs it was thought best to follow the life history of the following generation. The eggs with which these studies were started were brought from the field on August 21. They formeda compact group nearly an inch across, being placed closely side by side upon the under surface of the cotton leaf. The number of eggs deposited in a group varied, some having been found numbering between 900 and 1,000. Fic. 19.—Estigmene acrza: a, male moth; b, half-grown larva; ., mature larva, lateral view; d, head of same, front view; e, egg mass—all slightly enlarged except d, more enlarged (from Chittenden). > EGG. The eggs were nearly round, about two-thirds of a millimeter in diameter, and, when first deposited, of a pale yellow color. The surface of each was slightly granular in appearance. As the embryo became nearly developed the color of the egg changed to a dull blue, with a black spot near the middle of the top... Hatching occurred in four or five days. The percentage failing to hatch was very small and no para- sites were developed in this lot of eggs. LARVA. As they left the eggs the larvee were about 2.3"" long. Their color was a uniform dark brown, and the length of the hairs was nearly equal to that of their bodies. 22104—No. 44—04——6 82 The newly hatched larvz were placed upon fresh, tender cotton leaves and began at once to feed, eating only part way through, so as to leave intact the epidermis on one surface of the leaf. As a rule they chose the under side, probably in part for protection and in part because of the more tender tissue on that side. The length of the body during the first larval stage increased to about 10™" and the color became yellowish brown. In the second stage of the larva the coloration appeared more clearly. The subdorsal tubercles became black and prominent. There was an interrupted white dorsal stripe and lateral stripes of a tawny yellow color. The hairs were long and black. As the second molt was approached the subdorsal dark stripe became lighter in color and the black tubercles standing therein appeared more prominent. The length of the second stage varied between four and seven days, and during this time the length of the body increased to about 15". Feeding was almost entirely confined to one surface of the leaf throughout this stage. This habit of feeding only upon one surface of the leaves easily explains the failure to poison the caterpillar which was at first reported. At the beginning of the third stage the color of the larve appeared markedly darker than in the second. The subdorsal stripes, especially, were very dark, though the color was somewhat variable as it is in all stages. During this instar the larve began to consume the entire leaf tissue, that is, they ate clear through instead of leaving the epi- dermis upon one side. Midribs and heavy veins alone were left. The length of the stage varied between six and ten days. The length of the larva’s body increased to more than 30™". The fourth and fifth stages showed little change in general appear- ance. All the specimens bred were dark, while many found in the field were much lighter, and some which seemed to belong to the same species were of a bright, uniform yellow color. The length of the fourth stage varied between five and nine days and the average length of body became about 45"". The duration of the fifth stage varied between eight and twelve days and the length of the body averaged about 55™™". The entire time of the larval stage was found to vary between the extremes of twenty-four and thirty-seven days from the hatching of the egg to the spinning up of the larva. The mean average tempera- ture for this period was about 82.8° F., or almost 40° of effective temperature. PUPA. Pupation took place in about two days after spinning. The cocoons averaged about 30" in length by 10 to 12" in breadth. The length of the pupal stage, or from the spinning of cocoon to the emergence ee ee ye ee een 83 of the adult, varied between nine and sixteen days, in most cases being about twelve or fourteen days. The time required for the emergence of males seemed to average about one day shorter than that for females. ADULT. The moths of this species measure from 1 to 1; inches in length with the wings closed. The predominant color as seen from above is white with prominent black spots scattered over both the upper and under surfaces of the wings and in six rows, three ventral, two lateral, and one dorsal, along the abdomen. In the female the wings are white upon the under as well as the upper sides. The back of the abdomen, with the exception of the first and last segments, is of a brownish yellow color. In the males the under surface of the forewings, both surfaces of the hindwings, and the predominant color of the abdomen is brownish yellow, thus making the distinction of the sexes a very easy matter. GENERATIONS. The average time required for the development of this generation was very nearly forty-five days. The adults, all of which emerged, mated within a few days and the females deposited their eggs in the breeding cages. No attempt was made to breed another generation, but as numerous large larvee of this species were seen early the follow- ing spring, it appears that a fall brood of larve is normally developed and that this brood hibernates in the larval stage. No adults were seen early in the spring of 1903. Hibernated caterpillars taken into the laboratory spun up about the middle of May. In 1902; the eggs for the generation of worms which did so much damage during the latter part of July must certainly have been deposited by the last of June, and it is very probable, though the actual fact has not been established, that the adults depositing those eggs had come from hibernated caterpillars. Assuming that to have been the case, the normal number of generations for this insect in that locality is three. The period during which the life history was fol- lowed in 1902 was exceptionally hot, and it is therefore safe to say that the normal developmental period for each summer generation is about seven weeks. It is believed that in the Middle States this species has two gen- erations and in the New England States it has been found to have but one. INJURY TO COTTON. The occurrence of this caterpillar upon cotton is by no means rare. Jn fact, occasional specimens may be found in almost every cotton field, but it is only very rarely that they are as abundant and inflict 84 as serious injury as they did in the case recorded. The writer is informed by those who have seen this larva often before, that it never seriously injures cotton except in some cases where cotton is first planted upon new land. GENERAL NOTES. SOME INJURIOUS GARDEN AND FIELD INSECTS IN TROPICAL NORTH AMERICA. August 16, 1903, Mr. O. W. Barrett, entomologist of the Porto Rico Experiment Station, sent specimens of noxious insects from that country which are interesting because of their relation to species known to occur also on the mainland of the United States. One of these was an unknown species of Aphis, which is stated to seriously affect squashes. A leaf-beetle, Cerotoma denticornis Ol., very closely related to the bean leaf-beetle of the United States (Cerotoma trifur- cata), was said to be injurious to cowpeas. A flea-beetle, Systena basalis Duy., was injurious to Russian sunflower; while a leaf-hopper, Agallia tenella Ball., was stated to damage the leaves of beans, cow- peas, and other plants. Later, September 30, 1903, Mr. Ed. Ferrer, La Magdalena, Cayamas, Cuba, stated that Cerotoma denticornis did a great deal of harm to cultivated beggar-weed (J/esbomia sp.), which Ae erew wild in that vicinity, from 30 to 50 per cent of the weight of the leaves being a good estimate of what the beetle devoured. Diabrotica balteata, another leaf-beetle related to the corn root- worms was received from Mr. A. L. Herrera, City of Mexico, Mexico, with the statement made under date of December 3, 1902, that it was injurious to wheat at Salvatierra, State of Guanajuato. During July, 1903, we received from Dr. Silvio Bonansea, of the City of Mexico, a specimen of Scyphophor us acupunctatus Gyll., a weevil quite com- monly occurring in southern California which our correspondent stated was damaging henequen (Agave rigida). A short account of this species and a note on the occurrence of the larva in the interior of the stems of Agave mexicana has been given by Dr. Eug. Dugés in the Annales de la Societe Entomologique de Belgique, 1886, p. 33. A short note on the occurrence of the adults on trunks of grape- vine at Poway, Cal., where they feed on sap, was also published, in Volume V of Insect Life (p. 35). REMEDY FOR STORED GRAIN INSECTS IN CUBA. Mr. Limeon Poveda, jr., owner of a breeding farm in the suburbs of San Leandro, the municipal boundary of the Cuban town of Palma Soriano, known also as San Juan, who is also engaged in the practical study of agriculture, writes as follows in regard to the occurrence of weevils in maize and the remedies to be used in combating them: pa OG 85 In spite of the enviable fertility of the soil, which permits the gathering of the crops in less than three months, farmers can only receive a reward for their labor and sacrifice by the immediate selling of the crop as soon as harvested, because it quickly becomes infested by the weevil, which in a few days renders it useless. For the prevention of this damage the Department has assisted the agriculturists to make the following experiment: When the corn is harvested and to be gathered into the storehouse, the grain is sprinkled to a height of 12 to 15 inches and then covered by a layer, nearly covering it entirely, of the sawdust of cedar mixed with a little salt (about half a gallon), fol- lowed by a thick layer of maize, then by another thick covering of the cedar dust and a little salt, continuing the same process. This author presents the difficulty, in the practical outcome, of producing a flavor which is disagreeable to the animals and leaves them in a condition unfit for the market. BEETLES INJURIOUS TO HERBARIUM FUNGI. We received during March, 1903, through the kindness of Prof. T. D. A. Cockerell, from W. C, Sturgis, some interesting informa- tion in regard to injury by certain species of beetles to a collection of fungi and mycetozoa. Professor Sturgis, writing from Colorado Springs, Colo., states that his collection of mycetozoa has been much bothered by the attacks of small beetles which feed mostly upon spores, and especially of the Stemonitacex. He complains that some most beautiful and copious specimens were reduced to nothing but sticks and a powdery mass of black excrement within a period of a few weeks by these pests. Among the insects troublesome to his plants are the following: Arrhenoplita bicornis Ol. Injured Stemonitis, and was alone. Sphindus americanus Lee., very commonly met and destructive. Liodes obsoleta Horn., also concerned in injury. Beocera (2) sp., also concerned in injury. Professor Sturgis states that these beetles operate after the speci- mens have been dried and placed in the herbarium; that they prefer the specimen to the wood as food, and that their depredations are almost exclusively confined to the Stemonitis, Comatricha, and Lamprederma, genera whose species often show a dense tufted habit peculiarly susceptible to attack. A fifth species, presumably a Cioid from the description, is mentioned as the principal insect enemy to the specimens which have been considered. A WEST INDIAN FRUIT-TREE BORER. June 8, 1903, we received a communication from Mr. Bernabe San- chez Adan, Central Senado, Las Minas, Cuba, with accompanying specimens of the Bostrychid beetle, Apate carmelita Fab., which was reported to be destroying orange, plum, and almond orchards. The beetles were described as boring from the outside seeking the core, which they readily attacked, the trees perishing in a short time. By 86 the same mail we received a second letter, from Mr. J. H. Hemenway, Cienfuegos, Cuba, containing report of depredations by this same insect on the coffee plants, it being described as very common and completely destroying plantations. This species is mentioned in literature generally as Apate francesca Fab., which is a synonym of carmelita, the latter being the male and the former the female of the same insect. It may be remembered that a note was published on this species (Ins. Life, Vol. VI, p. 274) as boring in Lagerstroemia in Jamaica. SAY’S PLANT BUG. (Lioderma sayi Stal. ) One of the remarkabie outbreaks of the year 1903 was that of a large green pentatomid bug (Lioderma [| Pentatoma| sayz Stal.). It was most injurious to grain, and especially to wheat, but in some cases attacked a variety of other plants. Among interesting reports of injuries received was one from Prof. C. P. Gillette, who wrote, August 19, that many wheat fields in Montezuma County, Colo., had been reduced from 25 to 75 per cent. Fields of oats were also badly injured, and in some cases beans and peas were attacked. May 9, Prof. T. D. A. Cockerell reported an outbreak in Arizona. At that time the insect was so abundant that it threatened the ruin of the grain crop in the vicinity of Pima, Thatcher, and Fort Thomas. — It was noticed that the insect was common also on wild plants in that territory. At Phoenix, Ariz., and vicinity, Mr. Matthew M. Murphy reported considerable damage, especially to late wheat. Mr. C. C. Pitrat, Farmington, N. Mex., reported September 9 that this bug had caused much loss to the wheat crop of that vicinity, the bugs having first been noticed July 20, when the wheat was in the milk. Three or four bugs were found clinging to each head of wheat, seeming to suck the juice from the forming seeds. It was estimated that the bugs had badly damaged or completely ruined about half the wheat in San Juan County. It was observed that the bugs had a very offensive smell, like that of the common squash bug (Anasa tristis). Mr. J. J. Star- ley reported injury to potato vines at Fillmore City, Millard County, Utah. From specimens received from this latter source, eggs were deposited in July, and young were observed July 25. Reports of injury chiefly to grain were also received from Safford and Tucson, Ariz., and Cortez, Colo. AQUATIC BUGS OF COMMERCIAL VALUE AS FOOD. October 7, 1903, Dr. A. Hrdlicka, of the U. 8S. National Museum, suhmitted for examination a large package of insects which he stated were used as fish food in Mexico, whence they came. ‘These insects 87 were all of the family Corixide, or ‘‘ water boatmen,” and similar to species which are found in boreal America. We also received infor- mation that they were on sale in a well-known bird store in the city of Washington. The species were three in number, and were identified by Mr. Otto Heidemann, of this Office, as Wotonecta americana Fab., Coriva mercenaria Say, and C. edulis Champ., all of which are described in Biologia Centrali-Americana, Hemiptera-Heteroptera, Vol. H, by G. C. Champion. Writing of mercenaria, Mr. Champion states that it swarms in the large lakes near the City of Mexico, and much has been written about it from the economic point of view, the eggs, larve, and adults being collected and sold in Mexico as articles of food, it is said, for both man and birds, while of late years they were even being imported into England as food for caged birds. The food value of these insects appears to have been recognized since 1625, by Thomas Gage who is credited with being the first English traveler in Mexico. His observations have been confirmed by Say and Guérin, the latter stating that C. femorata is sold for the same purpose. Immense numbers of these ‘* water boatmen” are sometimes captured on the wing toward evening. Probably all of the ‘‘ water boatmen,” of which there are many species in North as well as Central America, could be utilized for the same purpose, it being merely a question of capturing them in sufficient numbers to make it profitable. The same month Mr. George L. Hopper, of the Bureau of Fisheries, Crockett Depot, Va., furnished samples of Mexican aquatic bugs of the same species above mentioned, including two other forms, one doubt- fully identified as 7ascripta. Mr. Hopper stated that the material sent for examination had just been received in several pounds in the dried state for experiment as food for young trout. The trout were eating them and doing well, and our correspondent was convinced that it was the best artificial food that had ever been used. He stated that the bugs were gathered in large quantities from Mexican lakes, especially Lakes Choleo and Texcoco. Their eggs are glutinous and adhesive to submerged objects in the same manner as is oyster spat. He adds that Coriva femorata is used in Mexico for the same purpose, and has long served as an article of food for the natives of Mexico. Concerning the manner of use of these insects as fish food, Mr. Hopper stated that as they were dry they were run through a coffee mill and ground as finely as desired, after which scalding water was poured over them to soften them. They were then mixed with 20 per cent of mush, and this he stated made the best food for small fish which he had ever seen tried, and he has had many years of experi- ence in this line of work. Thus prepared he stated the cost was about 5 cents a pound. 88 A NEW ENEMY OF THE PEAR. Dr. N. Cholodkovsky, of St. Petersburg, Russia, reports in the Zoologischer Anzeiger (Vol. XXVII, pp. 118-119, 1903) the discovery of a new species of Phylloxera, infesting the fruit of several valuable varieties of pears, and to which he gives the name of Phylloxera piri. He states that about the middle of September colonies of small and apterous, yellowish-green lice were discovered in small depressions around the stem of numbers of pears, covered with paper bags as a protection against Carpocapsa pomonella, at Aluschta, Crimea, Russia; that the infested parts eventually rotted, producing irregular blackish- brown spots on the surface surrounding the stem, and that the lice had apparently lived on the pears for about a month, during which time the young or larvee spread from one fruit to others. Thus far this species appears to be indigenous and confined to the south of Russia, and as far as recorded is the only one of this group of plant lice discovered as infesting fruit trees. The discovery of this new pest on the pear indicates anew the great danger of indiscriminate importations of fruit, cuttings, or growing plants from foreign countries without an adequate supervision and fumigation before shipment and thorough inspection of such a cargo prior to distribution in this country.—Tn. P. INJURY BY A CRICKET IN THE SOUTH. During the November 11 (1903) meeting of the Entomological Society of Washington the following notes were presented by .Mr. A. N. Caudell, the first portion being a letter received several years ago and the latter a report on the specimens by Mr. Caudell. Mr. Dempsey’s letter is as follows: JENA, CATAHOULA ParisH, La., May 7, 1887. As you requested February 21 last, I send you samples of the destructive locusts which are so numerous in this parish. They infest portions of the hills and swamp lands alike, doing irreparable damage to cotton, sweet and common potatoes, peas, and tobacco. They will not reach you alive, as they die in about twenty-four hours in confinement. ; Our farmers are seriously alarmed at their fearful increase and their destructive habits. Their holes in the ground are promiscuously scattered from a few inches to several feet apart, and seldom over a foot deep in the uplands, but they go much deeper in the swamp, as the soil is deeper and the subsoil softer. They are seldom visible in the heat of the day, and do their cutting at night, taking all they want down in the ground, where they eat as they please or feed their young ones. They never infest trees or injure orchards, but if they become much more numerous they may eat everything green. In 1852 I first noticed them eating young cotton only, and a few years back they began to eat sweet potatoes; now they eat peas and tobacco, and have attacked our gardens. Our parish is composed of small farmers, who lack the means and the knowledge of how to exterminate them, and I fear that for want of discipline, unity of action, or any system of organization that the most profound scientist would fail 43 89 to effect a radical cure. Were the evil only ameliorated it might save thousands of doliars and an immense amount of labor, which is worse than wasted by its disheart- ening nature. * * * They appear to go in colonies, eating one man’s crop while his neighbor’s across the fence is not injured. We find that rapid cultivation, large ‘‘gangs’’ of poultry, and numerous birds keep them in check; but they are becoming too numerous in spite of all we can do, MicHaeu Dempsey. Notr.—This insect of economic importance has existed for many years in the United States without being, so far as I know, mentioned specifically by any writer. It is a species of the gryllid genus Anu- rogryllus, which I have determined as A. antillarwm Sauss. When mature it is readily separable from its ally, A. muticus, by being apterous and having the elytra more abbreviated. Specimens of what I take to be the young have very small wing pads, but they are rarely discernible in the adult. The National Museum contains specimens from Florida, Alabama, South Carolina, Louisiana, and Virginia, where it is injurious to various garden crops, strawberries, peas, sweet and Irish potatoes, tobacco, and cotton. This species probably occurs not uncommonly in collections, but has never been recorded from the United States. Mr. Rehn tells me it is present in the collection of the Academy of Natural Science of Phila- delphia as Mogryllus saussured; but members of that genus have fully developed ovipositors, while Anurogryllus is peculiar in having that organ aborted.—A. N. CaupELu. IDENTITY OF A TINGITID FOUND ON CHRYSANTHEMUM. In Bulletin No. 10 new series (page 99), under the head of Extracts from Correspondence, a short note was published in regard to infesta tion of chrysanthemum leaves by a little tingitid bug received in June, 1897, from Alabama, the species having been identified at that time as Corythuca trrorata Riley. Dr. E. P. Felt has recently brought up the subject of the specific identity of this chrysanthemum pest, and Mr. Otto Heidemann, of this office, has furnished the following notes, which will be of value to the systematic worker. Under date of June 11, 1903, Dr. Felt sent specimens of the same species, stating that it is seriously injuring chrysanthemum for the past year or two at Coeymans, N. Y. According to Mr. Heidemann the insect in both cases is Corythuca marmorata Uhl., described in Proceedings of the Boston Society of Natural History (Vol. XIX, p- 415, 1878), there being nearly perfect agreement of the specimens with the description. The type of this species is in the Harris collec- tion now in the Boston Society of Natural History museum, No. 61, labeled in the handwriting of Uhler as C. marmorata. Corythuca trrorata is « MS. name of the late Prof. C. V. Riley. It has therefore never been described, and as it is exactly like Uhler’s marmorata, would be a synonym in any case. 90 CARBON BISULPHID FOR RED ANTS AND WHITE GRUBS. Mr. Harry B. Williams, 212 Summer street, Boston, Mass., writes in regard to the efficiency of carbon bisulphid’as a remedy for red ants and white grubs, both of which insects were troublesome on his lawn, that having tried hot water, kerosene, red pepper, and a few other such remedies, he wrote to this Department for information, receiving Circular 34 and Farmers’ Bulletin 145. In applying the remedies, he made holes about 4 inches deep in the lawn, 2 feet apart, inserted a small funnel, and poured a small quantity, about a tablespoonful, immediately into the funnel, pulling it out and cover- ing the hole with moist dirt. He noticed that if the bisulphid touched the grass it shriveled it at once; and if too large a dose was used, it had a tendency to kill the grass, making brown spots appear. He described the treatment as having produced very good results, having cleaned the lawn of both white grubs and red ants. This is the standard remedy for ants in lawns, and has frequently been advised for white grubs, but the expense of using it is such that it can not always be profitably employed in large fields, though it will answer very well for lawns, and for some gardens. AGONODERUS PALLIPES A PERMANENT ENEMY OF SPROUTING CORN. During the latter days of July, 1903, Mr. B. D. Wilson, Hetty, Tex., sent numerous specimens of the common little carabid ground beetle, Agonoderus pallipes, together with samples of sprouting corn which they had injured. He reported that there seemed to be twenty of these beetles to a single grain of corn. Out of 50 acres of June corn planted he felt satisfied that he would not obtain more than 5 acres on account of the ravages of this little pest. It is now a matter of upward of twenty years since this species has attracted attention by attacking the kernels of corn in Illinois. (See Forbes’s 12th Report St. Ent. Ill., p. 27.) In 1885 we received reports from Illinois and from Iowa that this species was damaging young corn by gnawing into the seed corn and eating the sprouting roots. Damage was said _ to be quite extensive (see Bul. No. 12, Div. Ent., 0. s., p. 45). ANTHRENUS DESTROYING TUSSOCK MOTH EGGS. In Technical Series, No. 5, we described a newly discovered habit of the larva of Anthrenus verbasci (varius) in feeding upon the living eggs of Hemerocampa (Orgyta) leucostigma. Since that time this observa- tion has not been duplicated. In October, however, Mr. D. C. Clark stated that he had noticed the same habit in Baltimore, and that he is confident that it has been during the past season of so common occur- rence as to account for the scarcity of the tussock moth caterpillars 91 upon Baltimore shade trees. Last year, in 1902, this species was about as prevalent as usual. The egg masses were about as abundant in 1903 as in 1902, but upon examination Mr. Clark could find com- paratively few which had not been eaten. He found the larve of Anthrenus and the cast larval skins in nearly every egg mass exam- ined. In fact, we may say, he could not find a single perfect egg mess to experiment with as to the time of hatching. This observation is of very great interest and importance. Down to the time of our note, above cited, this Anthrenus had not been known to feed upon living animal matter. Are its habits changing?’ ABUNDANCE OF THE RHINOCEROS BEETLE IN SOUTH CAROLINA. In a letter dated July 27, 1903, Hon. Wyatt Aiken, writing from Abbeville, 5. C., stated that the rhinoceros beetle (Dynastes tityus Linn.) had attacked swamp ash grown as shade trees in that vicinity, and that the odor proceeding from the beetles, which is well known to collectors of insects from its strength and persistence, was very obnox- ious. As a remedy, 80 trees were cut down by order of the town council, with the result that the offensive odor disappeared. The explanation is that the insects are more attracted to ash than to other trees, and with the disappearance of their favorite host plants in that vicinity they went elsewhere. Notes on this species, together with illustrations, were published in Bulletin 38 (on pp. 28-32). In commenting upon the occurrence of this insect the Abbeville (S. C.) Medium of July 30, 1903, states in an editorial that several years previously similar complaints were made at Magazine Hill, which was the particular locality where the insect was a nuisance, and that the city council had destroyed trees at Fort Pickens where the insects had been noticed, as also in other parts of the city. The trees were estimated to be worth $100 each, and the loss was therefore stated to be $8,000. ; THE LENGTH Gr THE FIBER IN THE COCOON OF THE DOMESTIC SILKWORM. Authorities and popular works differ greatly in their estimates of the length of the fiber in the cocoon of the domestic silkworm, Bom- byx mort. Published statements of the length of this fiber could be cited which range all the way from 1,100 feet to 11 miles. Even so good an authority as the Encyclopedia Britannica places it at 300 yards. Recent measurements made in the Division of Entomology show that with certain Milanese yellow cocoons raised in the United States from eggs purchased from France the fiber varies in length from 888 to 1,195 yards. 92 EFFECT OF THE BITE OF A MIDGE ON A HUMAN BEING. It is well known that the genus Ceratopogon, of the dipterous family Chironomid, or what are termed biting flies, of which the most conspicuous form is the so-called punky of the north woods of Maine, sometimes called by the Indians ‘*No-see’em.” It is some- what seldom, however, that the species caught in the act of biting can be determined specifically. Mr. F. W. Thurow, Harvester, Tex., sends specimens of Ceratopogon stellifer Coq., with report that it is very common in that vicinity (Waller County), and that a great many, people have felt its bite. It is sometimes called sand gnat or sand fly, but all agree that it is very tormenting, and that it is worse near ereeks that are choked with logs than elsewhere. When our corre- spondent first went to live in Texas he would pull off his shoes at night and sit down to read. After a while his feet and hands were burning as if he had been wading in nettles. For a long time he was of the opinion that the trouble was nettle rash, on account of the minute size of these little midges, which is well expressed by the Indian name ‘‘ No-see’em.” The bite of the flies appear to be more intense about the wrists and antles. THE QUAIL AS A DESTROYER OF CUTWORMS:. November 14, 1902, Mr. W. F. Wever, Commerce, Tex., wrote in reyard to the effectiveness of the quail in restraining the multiplica- tion of insects, more particularly cutworms: My grandfather had a low piece of bottom land that cutworms were always very bad in; and upon one occasion I shot a quail in the edge of this piece of land. When the negro woman went to dress the bird, its crop was so full that she cut it open, and found 17 cutworms in it. That stopped the killing of quail, so far as my grandfather’s place was concerned. I am satisfied that your Department could do some splendid missionary work along this line. We frequently receive similar communications testifying to the value of the quail as an insect destroyer, more particularly as a check on the increase of the Colorado potato beetle (see Insect Life, Vol. LV, p- 278, and Vol. V, p. 143). Within a radius of only a few miles of the Capitol, quails are quite common during the summer months, and come very close to cottages along the Potomac River front, and may be seen crossing roads ahead of carriages almost as freely as barnyard fowls; and it seems too bad that a bird which has a tendency to fre- quent the vicinity of farmhouses and fields of grain and other crops where it would aid in the control of insect pests should be destroyed by alleged sportsmen as soon as the open season begins. 93 : TOBACCO FOR THOUSAND-LEGGED WORMS. A writer in the Weekly Florists’ Review of April 9, 1903, Mr. Wil- liam Scott, states, in answer to a correspondent of that publication who requested a remedy for thousand-legged worms or millipedes working on his ferns and which he stated-were eating some of his asparagus seed, that thousands of these creatures appeared on the sur- face of rose beds, but that after putting bunches of tobacco stems on the surface to keep down *‘ green fly ” or aphides, it was noticed that the ‘‘thousand legs” lay around dead, and their demise could be attributed to nothing but the tobacco. Mr. Scott therefore advises that in order to rid greenhouses of ** thousand legs” to put plenty of fresh tobacco stems among the pots. ' LIGHTS AGAINST THE IMPORTED CABBAGE WEBWORM. Mr. H. M. Simons, who appears to be the first person who has had experience with //e/lula undalis in this country, wrote from Charles- ton, S. C., August 11, 1902, that he captures many of the moths with the aid of a barrel having all but four of the staves sawed out, leaving 4 inches from the bottom to form a tub in which to hold water. From the top of this a light is suspended which attracts the moths. The light barrels, as he terms them, were placed on plant seed beds of cabbage. A thin scum of kerosene was used in this experiment, but it is sug- gested that this be eliminated, in order not to destroy predaceous insects, such as ground beetles, which are almost sure to be attracted; this suggestion being made in view of the fact that the destruction of one individual of a beneficial species is equivalent to the destruction of perhaps 20 to 100 injurious ones. The useful insects can be easily picked from the water, and though they may apparently be dead, they usually recover and crawl away. HAIR WORMS IN CABBAGE. Many complaints have been made during the present year of what have been termed by various persons as ‘‘ snakes,” ‘‘ cabbage snakes,” **snake worms,” and the like, and the subject has attained consider- able newspaper notoriety. So many inquiries have been made as to the identity of the creatures and their alleged poisonous qualities that it has been thought well to give a short account of them, more particu- larly as many persons fully believe the insects to be poisonous. This is, of course, absurd, as the worms are not known to possess any toxic properties whatever, but it is certain that, although they are not injuri- -ous to the cabbages their presence is not desirable, as they really injure cabbage for sale. The specimens received during the year, with a few exceptions, have been found in heads of cabbage. We have ascertained 94 from Dr. C. W. Stiles, consulting zoologist in charge, Bureau of Animal Industry of this Department, that the species is Wermis albi- cans, Diesing,“ in each case represented by the female. The creature is not an insect nor a snake, but one of the hair worms of the family Gordiide. It has been well described by one of our correspondents as a white worm, looking like a piece of basting thread. It is usually found coiled or crawling about in the cabbage in which it is found. Its length when full grown is about 3 inches. This little hair worm has been reported in cabbage, with the usual account of its being injurious and poisonous, from Glades, Clayton, Ga.; Earleyville, Tracy City, Tenmile Stand, and Greenville, Tenn.; Chester and Tucapau, S. C.; Shreveport, La., and several other localities from which no specimens were received. It is usually stated to be found in the solid part of the head of cab- bage between the leaves. One correspondent says that it is a serpent, a vicious little reptile; others that it develops in stagnant water and transforms from horsehair, a very prevalent opinion among many people. ves Rte YY WASHINGTON: a “sh ‘ GOVERNMENT’ PRINTING OFFICE. ay. te 1904. 3 ‘ m Y } ‘i i recs “DIVISION OF ENTOMOLOGY. ae “Di 0. Howanp, Entomologist x it ‘Marwan, é in n linge of experimental field abork. oe Bg CHITTENDEN, in charge of breeding saperimelten. A. D. ‘Hopkins, in charge of forest insect anbeatigations.. LER Frank BENTON, in charge of apiculture. _— is a w. D. Hunter, in cheurge of cotton boll weevil investigations. s “ L. i aleanioin in charge of bollworm eid ad Set ete ions, ‘E. 'g. G. ines, ‘investigators. Nice AG: ie ‘Miss Hy A. KELy, special agent in silk piciguicnae : B.S. Cuirroy, F.C. Prarr, Aucust Bapoks Orro HEIDEMANN, A. a a KOorinsky, H. 8. Baran, assistants. — a Ww. E. Hips, W. es Fiske, G. H. Harris, H. E. Bone, A.W. Monin, J ' C. ‘M. WALKER, demponary field agents. ; Miss L. i. OWENSTER, artist. Fy 1% 4 ¥y : Kz % ; 4 yak tifa af, WOds his iy ’ \ : bee Ans Bul. 45, Div. of Entomology, U. S. Dept. of Agriculture. PLATE |. DEVELOPMENTAL STAGES AND WORK OF THE BOLL WEEVIL. Fig. 1, Cotton boll weevil; fig. 2, weevil feigning death; fig. 3, two eggs and feeding excavation in a square; fig. 4, full-grown larva; fig. 5, pupa, ventral view; fig. 6, pupa, side view; figs. 7-9 show transformation taking place within squares: fig. 7, larva, full grown; fig. 8, pupa; fig. 9, adult; fig. 10, weevils feeding on boll; fig. 11, larva developing in boll. (Figs. 1-10, natural size; fig. 11, two-thirds natural size.—Original. ) Po. DEPARTMENT OF AGRICULTURE, DIVISION OF ENTOMOLOGY—BULLETIN No. 40. L. O. HOWARD, ENTOMOLOGIST. THE MEXICAN COTTON BOLL WEENIE, PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST BY W. D. HUNTER and W. E. HINDS. WASHINGTON : GOVERNMENT PRINTING OFFICE, 1904. LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, DIVISION OF ENTOMOLOGY, Washington, D. C., February 20, 1904. Str: I have the honor to transmit herewith for publication an account of the Mexican cotton boll weevil, prepared under my direc- tion by Messrs. W. D. Hunter and W. E. Hinds, special field agents of this Division. Mr. Hunter has been engaged for three years in investigations of this very important injurious insect, his work extend- ing all through the infested portions of Texas and to some extent into Mexico. Mr. Hinds for two years has been devoting his whole time to this subject, having been stationed for the most part at Victoria, Tex., in charge of laboratory work. The bulletin as a whole is a remarkably careful and complete treatment of the entomological aspects of the investigation. It seems to me as complete a treatise of the life history of a single species as has ever been published. The necessity for the most perfect knowledge of every detail of the habits of this great enemy to the cotton crop must be obvious, since only upon such perfect knowledge can we authoritatively base remedial work and ean we authoritatively indicate the uselessness of many of the remedies proposed by ingenious and inventive persons. The six- teen half-tone and other plates and six text figures are an essential part of the report. ~ I recommend the publication of this paper as Bulletin No. 45 of this Division. Respectfully, L. O. HOWARD, Entomologist. Hon. JAMES WILSON, Secretary of Agriculture. bo Pen Pane E: The Mexican cotton boll weevil (Anthonomus grandis Boh.) has the unique record of developing in less than twenty years from a most obseure species to undoubtedly one of the most important economie- ally in the world. It was first brought to the attention of the Divi- sion of Entomology as an enemy of cotton in Texas in 1894. Before it had invaded more than half a dozen counties in the extreme southern portion of Texas several entomologists were sent to the region in con- nection with this work. Enough was soon discovered to indicate the most feasible plans for avoiding damage by the pest. These original plans, based upon investigations of the life history of the insect, with modifications, for the most part due to climatic conditions in regions quite dissimilar to the lower portion of Texas, are still the basis for all that is known in combating the pest. However, at that time it was necessary to pay particular attention to the immediate economic phases of the problem, and a detailed study of the habits of the inseet was impossible. In 1902, by the aid of a special appropriation by Congress, it became possible to establish a complete field laboratory in the portion of Texas in which the weevil had been known to exist at that time for about eight years, where a careful investigation could be conducted regarding the points in the life history of the pest that offered even remote chances of suggesting means of avoiding damage. The results of the work at this laboratory that have béen of more immediate economic bearing have already been published in farmers’ bulletins of this Department. However, as will be seen from the fol- lowing pages, a very large mass of information concerning all the habits of the boll weevil has been accumulated. Not only on account of the great economic importance of the problem and the demand for information from numerous quarters concerning the biology of the pest, but also on account of the fact that the methods followed in this work have been to some extent original, and may be of use in con- nection with the investigation of other insects, it is thought advisable to publish a great number of the observations that have been made. The historical and economic features, to which reference has been made elsewhere in the publications of the Division, are included to ‘bring together in convenient form. practically all that is known regard- 3 4 ing the species. Much information obtained by the earlier investi- gators of the Division of Entomology, Dr. L. O. Howard, Mr. C. L, Marlatt, Mr. C. H. T. Townsend, and Mr. E. A. Schwarz, has been used. On account of the painstaking character of the work of Mr. Schwarz, and his intimate knowledge of related species, his reports, largely unpublished, have been found especially valuable. In pre- senting this work the authors have taken care to state fully the data furnishing the basis for the various conclusions. Under each impor- tant heading will be found, first, a description of the methods and apparatus employed; second, a full and in many eases tabular state- ment of observations; third, the obvious conelusions. Care has con- stantly been exercised to avoid errors likely to result from artificial conditions in the laboratory. Bot re Estorical sae. = AM oY 2) 2\27° ieee mee RUnMey OMe Cevelopmenth). 2.2.62. k Jo Bub Laeo yk bet ts Tue kee USERS RRS Se 1 ces © gtr ORE Se a kl er ee Hatching ___ Hahinsoier osdeposited Outsider 2-2 92. e 2a ele IRErcentase Omens thab Match): 225 = See eee ee aii eed ok Thedlarvas. =o. - Growth -.-.- Effect of burying squares upon pupation and the escape of adults_- Theadult=_—-..-- InGlorevemergvoncersgt se 2 ese ee. eee 5 MwA (gt ere) Emergence - @hangesiaiteremencence. ash .-hee aha 2 ee as Se SIZOLO PavyiGONill Smear steed ae te nt ey ot 2 RNS a RES ad Se 8 Ft. eLAMOMOnsIZC LOL OOGSUDDLys -= oe een sear See ees ae \AVCETPELEN OVE CYS LUIS Vee ate Laie cs est oaks Duo inne ie Pee ees Oe ee ge ee ye ee oe Pro pOLMONS (OletHhersexes es sar Seay eh eee EO Oe ae 2 Cae ene heorliteniponisquares\s 2-2... a. wal 2 2 ace Oe es oe al encnnomutecontbollsalone: ==. 22. Sle se ek Stee I a Pek Length of life on cotton leaves alone __________- os Spa) Length of life with sweetened water and ee molasses Dia Ses (ee Length of life without food, but with water _------------ aa Lane ienebhh of life-withoutood or water _-..-._-. 2... 2222222292225. -- Cannibalism 21 wo wore YW WW W W W Ww ® W w co is) oo Ol me He RH CO WW W W OO © st W WW W W =) Page. TPIS yee oe as on Pah ee ae em a a ee a 36 Mood ha bits o-22 3. See MIs Se ee we Ae ra are ee Ti Ny Dieses era 37 arval f.9 240 a2 ond ee Bare. as ee 2 ae ee 37 Aah ae ot es et a a Zine Sep A a 37 Mirai ee cn f2 FR ae a regret Us RE A Sp re RD oe pe 39 ie) 00th (2 AE De etna eRe eR ey Rs Sey ea SN 39 Males:and females together 2 22 525 ei ene 40 Feeding of hibernated weevils on early cotton ____.______________- 40 Increase in leat area. of cobbon [8s ee eee eet a eee 41 Effects of feeding upon squares and bolls ____. __-_-___--_--_--_--- 43 Destructive power, by feeding ss elu. Sees 7 See 44 Susceptibility of, various: cottons. -< 259-22 he es ee 44 Has the weevil any other food plant?: 2 222.-. 25. <2 eee ee 47 Insects often mistaken for the boll weevil ..-.....-------.+.2.£.<_12= 48 iis*cotton=seed meal attractive. 2922522. 8 ain see ee eee 50 haboratoryobservations,) -- 2 = ee eee ees 50 Tela MbeStA Sos 2 US ee OT Aad ee a et 51 The possibility of baiting weevils with sweets _______________________- 52 Adtractiveness: of various sweets... 4.0.2 2202.5 4. so 2k ee ee 52 Attractiveness to hibernated weevils in laboratory__.____________. 53 Influence of sweetened water upon feeding of weevils on cotton DIAMbS she eos eae ta Raat yee: fae es ee 54 Field tests for hibernated weev iis, using pure molasses___________- 55 Beisnine déathy 203 20. eee 2 RU ee ee ee eee 56 Reproduction =. ssie2 sos an woe Seat es ee ee ee 56 Method of making field observations upon work of weevils___________. 56 Mertilization. 2 -2t2e ie. oe 2 aan 2 nea 7 ee ee eee D7 Aeron berinnins Cop Ul attOTps 2 et oe ee 57 Sexual attraction and duration of copulation___.____.___2..___-_.- 57 Duration of fertility in isolated females. ________ -_______..__._-__- 58 @OVAPOSMIOU, 52.2 Sse S Sas, a Re: 58 Age.of beginning Oviposition <2) = fi eee 58 Examination of squares before oviposition Seu SlBp ee us Se 59 Selection of uninfested squares for oviposition____.._____________- 59 Laboratory observations ____________- PRE eE POE PE Cee ear 8 Sele SES) 2 60 Field observations _____ ae gens hrs pane Pee Rm one ee ba | 61 Activity of weevils in different parts of the day_____.________.___- 63 Place:okeroideposifon: 330s ees Se ee eee ee ee 65 Position of weevil while puncturing for oviposition ________-______- 65 The Act OLsOVAPOSItION a2. tse 2 eee an eee et eae ea 66 Time wequired comdepositvan lego = sete = ate. eee eee ae tae 67 Rate of oviposition—average, maximum______________.__...-_--. x 68 Stimulating effect of abundance of squares on egg deposition _____- 69 Relation-of warts'to oviposition: o: 26220 Se a eet Se ee 69 Effects of oviposition upon squares—flaring, falling. _____________- 70 Period of oviposition ss 8 ee ee ere ei Eten Ay Tae EE eee 72 Does parthenogenesis occur? _______-__------..--- i ahd Ee oe ae 72 Development! $2260.42 eae oS ol Pee rR ane eR ene ee Ape See ne 73 Percentage of weevils developed from infested Squares 27 a. t= eee 73 Development of weevils in squares which never fall_________.________- 73 Length of life cycle _________- es ae EES oe 74 ‘Broods.or generations... - 2 CN Ack ee 0 oe Sie en, A ee ee eee 75 Development—Continued. Thermal influence upon activity and development .__-_- .----.-------- Laboratory experiment in effect of temperature upon locomotive SRE la eee ee ee a tat ME Sn a te es Sh as fe 2 [eter citi OT eee ee arene ele mene eee es 225 a ee a fee ee ee Se Length of hiberenrren! Period as". = 55=.< S22 SS AA ae eS ee Apparently favorable conditions for hibernation _______.-_-.---------. Percentage of weevils hibernating successfully ---....-.-.--+- .------- SEE SUTTE LETS] 1°0) os gion ee ae ee gd no Ors It Sat ANE SPST HMereencem rom) OlDOrMaAtON 242. See el fos ee eae Apparent dependence of reproduction upon a rood obtained from squares _ IPTOSFCSS OLaniestamloOnunhioldses. 7.2 2526S GE S20 eS ae NWieewilein iiyne Se UenerproOmuehOne 52-5 oe a2 = nee sa a ee RGlaION oO eaCe Vl ashOmmlODICLOD i222 225 2 ee ee ee Some measonsor early destructioniof stalks — .-_--22---. 2-2 J22 8 AG ermMaOMme ae 8 kee he ee Ly a D2 POON Ate Pak Re ete Bet Weevils in seed houses at ginneries_____________---------- ESAT chit She BL Melee COMERO se sews ee oS pte he ts ON pe ES ns a cee oe A Mechanical conucoly oo Ss aetna Sees ESTE A Chee h oot tee Meee ce Aaa ee Pilose obstacles 46. weevil EORTESS ARS Sepa alt A eek pe Cia gee Ce unge Destruction of larvee and pupz in bolls and squares by abnormal ‘DLanb FOTO wyitlige me? eer rete Oe ener ss de fey ol oe DP Gime .COMbLOles wea nts oe > Ee ea eee ei ea nae Ret Influence of climatic conditions upon weevil multiplication and Fitts] Us VR eR ee YAM ony se es Se cate ee Effect of rains upon development of weevils -_._____._.----- ----- Effects of wet winter weather on hibernating weevils____________. HTECtshOl OVeLHOW Adm elds) seam eres eae eee Se Se Laboratory observations upon time weevils will float and endure BUIDINGEXCN CCM are Aah ate ters eeenee Poe Se a eee Like MPS os Seah sp TENS Probabilities as to influence of climate on weevils in cotton regions TODA OW IEC ALCO err ins Ag wd Ses te em fs Seal ES ALISA IDISGa Se Spree pie nie ae SA eee Bee Se ee fh hg Bene Se ee a we JEEVES HGS) ot = costae Spot ns ee a ae EEN © Niece Re ete eee eS Ce eRe ae Brecdino Omparaskbesos. == 52-9) ey 2S. 4. es 2G HUCTELOL LCS WUGTULTEUCO SUS = tes ets ee en A a red uborye Clemens pee ee eae gorse She aoe. el college Pope ene Th aySeVGltisy SA OSE wae EE i Pot oe? Se eee Se eee ees ee Himilewmeansio- = sees 2 ye ee ees Sek ee ee ee [SIG 0) 1a as eee Oe ee, ae ae eee ba a ees te eR. nS 100 101 104 105 105 107 109 109 110 110 111 112 113 PLATE I. II. II. IV. ILLUS PRAT PONS: PLATES. Fig, ..1.—Cotton: poll nweevale ano: 52 eee ee See eee Frontispiece Fig. 2.—Weevil feigning death ___-__22: 2.22 25-52 -e Frontispiece Fig. 3.—Two eggs and feeding excavation in a square_-. Frontispiece Big, 4.—Pall-erown larva: 1 oe feeble ae eee ee Frontispiece Fig: 5,—Pupa, ventral view - 2222s see Sees Frontispiece Fig. »6:—Papa, sideswiew 2224.05. 5-cee eee or ee Frontispiece Rie 7 Larva; toll-prown 5202-2 oso Se ee Frontispiece Big. 8.=-Papa sac tie Loe eee ee ere eee Frontispiece Piles. 19s A Gali ek fe ee tek ee Bn Aa ee Frontispiece Fig. 10.—Weevils feeding on boll_-_-----.---------.------ Frontispiece Fig, 11.—Larva developing im boll .: 2-2... .--.-----22.-=-- Frontispiece Fig. 12.—Collection showing life history and work of boll weevil _- 24 Fig. 13.—Two weevils feeding on a square __-------------------- 24 Rig. 4 ee isolated. 23s Su ake ees See ee ee 24 Fig. 15.—Full-grown larva in square_-.-.-= 2. -225.25.-5---=s3-5 24 Fig. 16.—Full-grown larva isolated --__...-..-------- ------------ 24 Pre, 07+ -Prpia ca. 2 ek Soe aes ee ee ee ea eee 24 Fig. 18.—Adult ae esterase Sie NS he. hear he ay a 24 Fig. 19,—Large larvye'in lates boll) 2.2. 22s. oe eee 24 Fig, 20,—Pupal céell-in boll broken open.22---- 222. - -=25_<-= 52 24 Fig. 21.—Emergence hole made by weevil in square _-_--__--_----- 32 Fig. 22.— Weevil escaping normally from boll __-..------------- 32 Fig. 23.—Apparatus used in breeding weevils -_-.--------------- 32 Fig. 24.—Larva destroying the ovary and preventing bloom in 32 large square. << 2000 een ee ee eee 32 Fig. 25.—Leaf fed upon by weevils in confinement --------_----- 32 Fig. 26.—Emergence hole of weevil from boll which never opened - 32 Fig. 27.—Larva in square, ovary untouched .---.----------------- 32 Fig. 28.—Large and small larve in boll __---- of Sires Se ea 32 Fig; 29.—Square much fed apoms. 25... Sh yo Sense eee eee eee 48 Fig. 30.—Distorted bloom, caused by feeding upon large square- - 48 Fig. 31.—Blooms distorted by feeding punctures, open but imper- 48 ROGUE SA ee eee Fe Se os eee 48 Fig. 32.—Small boll riddled by feeding punctures -__------------- 48 Fig. 33.—One lock of boll destroyed by feeding punctures -_--_--- 48 Fig. 34.—External appearance of large boll much fed upon -.----- 56 Fig. 35.—Internal appearance of same boll -__. - .----------------- 56 Fig. 36.—Cages used to confine weevils in field -._.-------- ------ 56 Fig. 37.—Plant showing tagged squares from cage work- -------- 56 - IPWAT, OX: Fia. XI. Se; XIII. XIV. xy: XVI. we So Ole OO Map of area infested by weevil . Mexican boll weevil, head showing rostrum and antenne___.. . Diagram showing activity of 5 female weevils....._..... , . Bracon mellitor . Enemy of boll weevil, Pediculoides ventricosus____.________. Bray . Solenopsis debilis var. tewana 22... 2-22 Eee Nt AE 9 Fig. 38.—Boll showing two locks destroyed by two feeding punctures made by a male weevil_____._______._____ Fig. 39.—Square showing external appearance of two egg punc- UIDRERS. se ak Rh SE lee a NESE re eee ae ee (FUSS) AN ag Ry re ate Ee, SI pe eee OE ee a aed Fig. 41.—Egg deposited on inside of carpel of a boll__-__ = ___- Big./42.— Normal and flared squares .-.. 2... 0-2... Big. 43.—Three largé larve in a boll _._.._.._____..-.2 2... -... Fig. 44.—Four pupal cells from bolls on left compared with four Cobmum cecesiom Ment" Pec ss. 8 fe ee Fig. 45.—Device used to test attraction of molasses in the field apices yr weg arenes a Re fa ret ve a Fig. 46.—Fallen squares on ground in field__________.________. Fig. 47.—Squares dried and still hanging upon the plant______ Fig. 48.—Device used to test relative attractiveness to weevils of American and Egyptian squares ___.____________ Fig. 49.—Device used to test effect of temperature upon weevil SLT aS oe CORR Se a A = eae A a a ee Fig. 50..—-Comparison of pilosity on ‘‘ King” (at left) and ‘“ Mit Atificg a (ates ih) Stemps.s= 5. ee ee ye Fig. 51.—Locality found very favorable to hibernation of many Figs. 52 and 53.—Mexican cotton boll weevil (Anthonomus GrOMATS yD wee 2 Bence eet oh Ars eset 2A Mh ope LEST aI 2-1) CY 0 sea gk ea eS ERE we ete Ve Fig. 55.—Acorn weevil (Balaninus uniformis auct.) a, female, dorsal view; b, same, lateral view; c, head, snout, AN hMibE MTA On Ne aro ok Atte Pepe ee em Fig. 56.—Apple curculio (Coccotorus scutellaris)..-- === Fig. 57.—Plum gouger (Anthonomus prunicida) _________ . Be Dar-— We snores scapmlins 2) Gee or he Ee Figs. 59 and 60.—Transverse Baris (Baris LEGMSUCTSG)) eee eee Bue Ol. —Cenerenis Menicelus. Cy 22. 2 ee 8 Fig. 62.—Coffee bean, weevil (Areecerus fasciculatus): a, larva: Lelie. 3 SN Ces 07 04 8 Pelee a Mar eNE LSS ane RENE Figs. 63 and 64.—Chalcodermus ceneus ________________.._____. Figs. 65 and 66.—Sharpshooter (Homalodisca triquetra) __.___. Fig. 67.—Cotton stainer (Dysdercus suturellus).____.___.. ___ Fig. 68.—Cotton stalk borer (Ataxia erypta).__....._________- Fig. 69.—Imbricated snout-beetle (Epiceerus imbricatus) : Fig. 70.—A snapping beetle (Monocrepidius vespertinus)-_____ TEXT FIGURES. i rae bh Bs r re, x A aaa ee Meee § Seeee ‘ i $ ee) BAIS de ages Ass 2 Sie a Cea Sears Wid Sie: eed) s Sota eas st eee A one Se Son aeaabk Fawitctit! az = 3 aed » ct i e ® _ * Cn ‘ Fr Pt _ n'y. << A at tng hae ah tew ele > ate’ ets as a. P ' -s , * iM “ ' ~ ; AY Ans sis athe dg : c + =r Are al A Ly f J re, yf P aio Sree yee GF iv) #arat ueyek 1 2%, “iy ae areee oe Bie eG tt 5 pias ee ie mr Ci Re ghy Slt OAS pee Sa aed lates ey agg) ee ee ee ws ’ hs ig a eS » \ PAR Re ES) tes er, See Are af. our xe } ‘ ke re. ' aa ) . ‘ ro hes fe ' f - nS 2 = : ca | — . * = Tete Kei Se) o' £ ube Pras? + Oe ¥ i," % J OG Pee Py Sat , r Oo 1 Pepa ode bia At Me Be. be (ae le eet a A aber dk i ; -~ > oe ee : Sw, Peat gree ye Se ‘ Seta ree ee rs P hes ks od] <7 atta" we. peace rs es ~ ; SO pe aid et OS Cee, eT, " oy ie ; 5 : ‘ Cait Ay :s k " — Ss Pe se bs byte Psd Ay . 7 ~. e'ssiem'> Was "am y >! op) oe a ee ae a eB ge 2 welt et Bl zy a per’: , i Mae 5 ale Fad ae Bi tot Se *. 2 * 4 a Ty ‘a Ps = ys ve : ? i Paes eee 4 " ’ fo « i : Te ‘ : tae Pads oi. te Ps 2 ‘na rae + ee An ee : RAL ROA yee ge eC a : . mm a J Pho 7 pon 4 WJ ify ev ALANS, ved tlie Pe ut Palin, rad eae = i= “ AT he gtomaditn Wt Rane Wy RESET Ad Do he wha EP Ggier 2 we A ’ ied is ° roa AA acl adie ¥ Le > pla; iS Ce tee a hey Vey - it) Wane a wi Os RY et a ese ie BRS ere 5 r eee Me y ; 7 Ay fe Pei <3\4 THE MEXICAN COTTON BOLL WEEVIL. GENERAL CONSIDERATIONS. HISTORICAL. There is very little certainty regarding the history of the Mexican cotton boll weevil before it came to the attention of the Division of Entomology in Texas in 1894. The species was described by Boheman in 1845 from specimens received from Vera Cruz, and it was recorded by Suffrian in 1871 as occurring at Cardenas and San Cristobal in Cuba. Written documents in the archives at Monclova, in the State of Coahuila, Mexico, indicate that the cultivation of cotton was prac- tically abandoned in the vicinity of that town about the year 1848, or at least that some insect caused very great fears that it would be nee- essary to abandon the cultivation of cotton. A rather careful inves- tigation of the records makes it by no means clear that the insect was the boll weevil, although there is a rather firmly embedded popular notion in Mexico, as well as in the Southern United States, that the damage must have been perpetrated by that species. As far as the accounts indicate, it might have been the bollworm (Heliothis armi- ger) or the cotton caterpillar (Aletia argillacea). From the time of the note by Suffrian regarding the occurrence of the weevil in Cuba in 1871 up to 1885 there has been found no pub- lished record concerning it. In 1885, however, C. V. Riley, then Entomologist of the Department of Agriculture, published in the report of the Commissioner a very brief note to the effect that Antho- nomus grandis had been reared in the Department from dwarfed cot- ton bolls sent by Dr. Edward Palmer from northern Mexico. This is the first account associating the species with damage to cotton. The material referred to was collected in the State of Coahuila, supposedly not far from the town of Monclova. The exact date at which the insect crossed the Rio Grande into Texas is as uncertain as the means whereby this was accomplished. All that can be found, which is mostly in the form of testimony of planters in the vicinity of Browns- ville, indicates that the pest first made its appearance in that locality about 1892. In 1894 it had spread to half a dozen counties in the Brownsville region, and during the last months of the year was brought to the attention of the Division of Entomology as an impor- tant enemy of cotton. Mr. C. H. T. Townsend was immediately sent 11 12 to the territory affected. His report was published in March, 1895. It dealt with the life history and habits of the insect, which were then completely unknown, the probable method of its importation, the damage that might result from its work, and closed with recom- ‘mendations for fighting it and preventing its further advance in the cotton-producing regions of Texas. It is much to be regretted that the State of Texas did not adopt at that time the suggestion made by the Division of Entomology that a belt be established along the Rio Grande in which the cultivation of cotton should be prohibited, and thus cut off the advance of the insect. The events of the last few years have verified the prediction of the Division of Entomology in regard to the advance made and the dam- age caused by the insect. In 1895 the insect was found by the entomologists, who continued the investigation started the year before, as far north as San Antonio and as far east as Wharton. Such a serious advance toward the principal cotton-producing region of the State caused the Division to continue its investigations during practically the whole season. The results of this work were incorporated in a circular by Doctor Howard, published early in 1896, in both Spanish and English editions. An unusual drought in the summer of 1896 prevented the maturity of the fall broods of the weevil, and consequently there was no exten- sion of the territory affected. It should be stated in this connection that the region from San Antonio to Corpus Christi and thence to Brownsville will frequently pass through similar experiences, which will be quite different from anything that may be expected to occur in regions where the rainfall is more certain. In 1900 as well as in 1905, in all or part of the region referred to, the numbers of the weevil were reduced by climatic conditions, principally a scanty rainfall, so that they were comparatively unimportant factors. During 1896 the investigations were continued and the results published in another circular issued in February, 1897. This circular was published in Spanish and German, as well as English editions, for the benefit of the very large foreign population in southern Texas. The season of 1897 was in many respects almost as unfavorable as that of 1896, although the pest increased its range to the region about Yoakum and Gonzales. Although this extension was small it was exceedingly important, because the richest cotton lands in the United States were beginning to be invaded. The problem had thus become so important that Mr. Townsend was stationed in Mexico, in a region supposed to be the original home of the insect, for several months to discover, if possible, any parasites or diseases that might be affecting it, with the object of introducing them to prey upon the pest in Texas. Unfortunately nothing was found that gave any hope of material assistance in the warfare against the weevil. The season of 1898 was very favorable for the insect. Bastrop, 18 Lee, and Burleson counties became invaded, and some isolated colo- nies were found across the Brazos River, in Waller and Brazos coun- ties. Investigations by the Division of Entomology were continued, and a summary of the work, dealing especially with experiments conducted by Mr. C. L. Marlatt in the spring of 1896, was published in still another circular. At this time the legislature of the State of Texas made provision for the appointment of a State entomologist and provided a limited appropriation for an investigation of means of combating the boll weevil. In view of this fact the Division of Entomology discontinued, temporarily, the work that had been carried on by having agents in the field almost constantly for four years, and all correspondence was referred to the State entomologist; but, unfortunately, the insect continued to spread, and it soon became apparent that other States than Texas were threatened. This caused the work to be taken up anew by the Division of Entomology in 1901, in accordance with a special appropriation by Congress for an investigation independent of that being carried on by the State of Texas and with special reference to the discovery, if possible, of means of preventing the insect from spreading into adjoining States. In accordance with this provision an agent was sent to Texas in March and remained in that State until December. He carried on cooperative work upon eight of the larger plantations in the weevil region. The result of his observations was to suggest the advisability of a considerable enlargement of the scope of the work. It had been found that simple cooperative work with the planters was exceedingly unsatisfactory. The need of ameans of testing the reeommendations of the Division of Entomology upon a large scale, and thereby furnish- ing actual demonstrations to the planters, became apparent. Conse- quently, at the suggestion of the Department of Agriculture, provision for an enlargement of the work was made by Congress. Agreements were entered into with two large planters in typical situations for test- ing the principal features of the cultural system of controlling the pest upon a large scale. In this way 125 acres at Victoria and 200 acres at Calvert were employed. At the same time the headquarters and laboratory of the special investigation were established at Vic- toria, and such matters as parasites, the possibility of poisoning the pest or of destroying it by the use of machines, as well as investigat- ing many of the features of its biology that were still absolutely unknown, were given careful attention by a specially trained assistant whose services were procured for that purpose. The results of the field work for this year were pubiished in the form of a Farmers’ Bulletin entitled ‘‘Methods of Controlling the Boll Weevil; Advice Based on the Work of 1902;” but on account of the late date of the establishment of the laboratory (June), and the consequent incom- pleteness of many of the records, it was not thought advisable to publish anything concerning the laboratory investigations. During 14 this season cooperation was carried on with the Mexican commission charged with the investigation of the boll weevil in that country, which was arranged on the occasion of a personal visit of Dr. L. O. Howard to the City of Mexico in the fall of 1901. Specimens of parasites were frequently exchanged, and through the courtesy of Prof. A. 1. Herrera, chief of the Mexican commission, an agent in charge of the investigation in Texas visited the laboratories at the City of Mexico and Cuernevaca, where a study was made of the methods of propa- gating parasites, especially Pediculoides ventricosus Newp. A large number of specimens of this mite was brought back to Texas, where they were carried through the winter successfully and used in field experiments the following season. The favorable reception by the planters of Texas of the experi- mental field work conducted during this season, with the increased territory invaded by the pest, brought about an enlarged appropria- tion for the work of 1905. By enactment which became effective on the 4th of March $30,000 was placed at the disposal of the Division of Entomology. It thus became possible to increase the number and size of our experimental fields as well as to devote more attention to the investigation of matters suggested by previous work in the laboratory. Seven experimental farms, aggregating 558 acres, were accordingly established in as many distinet cotton districts in Texas. Despite generally very unfavorable conditions the results of this experi- mental work demonstrated many important points. The principal ones are detailed in Farmers’ Bulletin No. 189 of this Department. DESTRUCTIVENESS. Various estimates of the loss occasioned to cotton planters by the boll weevil have been made. In the nature of the case such estimates must be made upon data that is difficult.to obtain and in the collee- tion of which errors must inevitably occur. There is, of course, a general tendency to exaggerate agricultural losses, as well as to attrib- ute to a single factor damage that is the result of a combination of many influences. Before the advent of the boll weevil into Texas unfavorable weather at planting time, summer droughts, and heavy fall rains caused very light crops to be produced. Now, however, the tendency is everywhere to attribute all of the shortage to the weevil. Nevertheless, the pest is undoubtedly the most serious menace that the cotton planters of the South have ever been compelled to face, if not, indeed, the most serious danger that ever threatened any agri- cultural industry. It was generally considered, until the appearance of the pest in Texas, that there were no apparent difficulties to prevent an increase in cotton production that would keep up to the enlarging demand of the world until at least twice the present normal crop of about 10,500,000 bales should be produced. Now, however, in the opinion of most authorities, the weevil has made this possibility very Lo doubtful, although the first fears entertained in many localities that the cultivation of cotton would have to be abandoned have generally been given up. An especially unfavorable feature of the problem is in the fact that the weevil reached Texas at what would have been, from other considerations, the most critical time in the history of the production of the staple in the State. The natural fertility of the cotton lands had been so great that planters had neglected completely such matters as seed selection, varieties, fertilizers, and rotation, that must eventually receive consideration in any cotton-producing coun- try. In general, the only seed used was from the crop of the preced- ing year, unselected and of absolutely unknown variety, and the use of fertilizers had not been practiced at all. Although it is by no means true that the fertility of the soil had been exhausted, neverthe- less, on many of the older plantations in Texas the continuous plant- ing of cotton with a run-down condition of the seed combined to make a change necessary in order to continue the industry profitably. A careful examination of the statistics, to which more complete ref- erence is made in Farmers’ Bulletin No. 189, has indicated that the pest causes a reduction in production for a few years after its advent of about 50 per cent, but at the same time it is evident that most planters within a few years are able to adopt the changes in the sys- tem of cultivating this staple that are nade necessary by the weevil, so that the damage after a short time does not compare with that at the beginning. Upon the foregoing basis, during the season of 1903 the weevil caused Texas cotton planters a loss of about $15,000,000, and this estimate agrees rather well with estimates made in other ways by the more conservative cotton statisticians. A similar esti- mate made in 1902 led to the conelusion that the damage amounted to about $10,000,000. It consequently appears that during the years the pest has been in Texas the aggregate damage would reach at least $50,000,000. Many conditions of climate and plantation practice in the eastern portion of the cotton belt indicate that the weevil prob- lem will eventually be as serious east of the Mississippi as it now is in Texas. According to the estimates of Mr. Richard H. Edmunds, the editor of Manufacturers’ Record, the normal cotton crop of the United States represents a value of $500,000,000, the extreme ulti- mate damage that the pest might accomplish over the entire belt would be in the neighborhood of $250,000,000 annually, provided none of the means of avoiding damage that are now coming into common use in Texas were adopted. In spite of the general serious outlook, however, it must be stated that fears of the damage the weevil may do are very often much exaggerated, especially in newly invaded regions. It isnot at all necessary toabandon cotton. The work of the Division of Entomology for several seasons has demonstrated that a crop can be grown profitably in spite of the boll weevil, and this expe- rience is duplicated by many planters in Texas. 16 TERRITORY AFFECTED. At the present time the boll weevil has not been found in the United States outside of Texas (see fig. 1) except in three instances in Louisiana. In one of these cases, at the sugar experiment station at Audubon Park, in the vicinity of New Orleans, the circumstances have led the State authorities to the conclusion that the pests were purposely placed in the fields. The other two cases are isolated oc- currences in Sabine Parish, in the extreme western part of the State. Both of these are apparently traceable to importation from the oppo- site county in Texas, in cotton seed used for planting purposes or possibly in hay. The authorities totally destroyed the cotton grow- ing at the experiment station at Audubon Park, La., as soon as the presence of the weevils was discovered. As no cotton is grown within 9 miles of that point, it seems altogether likely that the colony may have been completely exterminated. Similar action is being taken regarding the two colonies found in Sabine Parish. In Texas the infested area extends from Brownsville, where the weevil originally entered the State, to Sherman. Shelby and Morris counties represent the extreme eastern range. The cotton acreage involved in this territory includes about 30 per cent of the cotton acreage of the United States, which produced in 1900 about 35 per cent of the total crop of this country, or about one-fourth of the crop of the world for that year. There is, however, a considerable belt between about the latitude of Dallas and the Red River where the pest does not occur in uniform numbers in all cotton fields, and con- sequently the general damage has not been great. Itmay be a matter of only two or three years before it will become sufficiently numerous to cut down the total production. There are some features of special interest in the situation in Cuba. Although the weevil has long been known to oceur in the island, it has attracted very little attention on account of the fact that the eul- tivation of cotton was abandoned fora long time in favor of crops that have been more profitable. Now, however, with the better price of the staple and rather unsatisfactory returns from some other crops, cot- ton is being planted upon a considerable scale. Mr. E. A. Schwarz was sent to the island on two occasions to study the conditions there. Although his report refers especially to the Province of Santa Clara, it is probably true that conditions similar to those he describes obtain everywhere. He found that the entire province is naturally more or less infested by the boll weevil, and that weevils did not spread from cultivated cotton planted with seed obtained in the United States to the wild plants, as at first supposed, but from the latter to the former. The weevils were found to be more numerous on the kidney cotton growing wild than on the loose cotton (seminiella). The latter, when growing alone, was usually found to be free from weevils, but lable to be infested when growing in the vicinity of kidney cotton. A large WILBARG c BAYLOR | ARCHER] CLAY |MONTA] COQME Ea ray apes aR eee HROCK. | YOUNG | JAGK,4 ‘WISE DENTON | COLLIN | HUNT > 4 CaM / 4 res | [ones Alona ay Se ested || Ls A an lees peer md XN | oe | eT ‘ » ‘ % = Tas es \s ime sk a4 tasaue| St | N aul =t ’ ‘ | ENCINAL elise | \ W/ 71 NGS PION ie pai is Sean Vb eae a i Fig. 1.—Map showing area infested by Mexican cotton boll weevil (redrawn. ) 21739——-No. 45—04——2 18 number of wild cotton trees growing in the vicinity of dwellings or growing entirely wild are always infested, and here the weevils are more numerous, but never aS numerous as on the cultivated Egyptian cotton. At one locality, where a large number of kidney cotton trees were growing (about 50 plants, some of them probably 20 years old), it was found that at least one out of every twenty squares had been punctured by the first week in March. From Mr. Schwarz’s report it does not seem that there is a very promising outlook for cotton raising in Cuba. The presence of wild perennial cotton, upon which the weevil probably exists everywhere, will always be a source of danger. The long moist seasons and mild winters will form more favorable conditions for the pest than will occur anywhere in the United States. PROSPECTS. The investigations of the life history of the weevil that are referred to in detail in the following pages have indicated that the most im- portant elements in limiting the spread of an insect—namely, win- ter temperatures and parasites—in this case offer no assurance that the pest will soon be checked. For the past ten years, except where local unfavorable conditions have interfered, it has advanced annu- ally a distance of about 50 miles. The insect is undoubtedly chang- ing its habits and adapting itself to climatic conditions in new regions that it is invading. It is undoubtedly true that it has acquired an ability to withstand more severe frosts than occurred in the vicinity of San Antonio in 1895. Except in a few particular regions, however, it does not seem that the continued spread will be as rapid as it has been. The country between Gonzales County and the Red River is practically a continuous cotton field, and the prevailing winds have undoubtedly favored the northward spread of the insect. Similar conditions will now favor a rapid extension into the Red River valley in Louisiana, and likewise there seems no doubt that the spread will be rapid in the Yazoo valley in Mississippi; but in most other situa- tions throughout the belt the cotton fields are smaller and more iso- lated than is the case in Texas; consequently it is to be supposed that the spread of the pest will be retarded somewhat. : Basing estimates on a careful study of the distance the boll weevil has traveled each year, as well as upon some attention that has been paid to the means whereby it reaches new territory, referred to more in detail hereafter (p. 94), it seems safe to predict that in from fifteen to eighteen years the pest will be found throughout the cotton belt. During the time it has been in Texas there has been no tendency toward dying ovt, and in south Texas the pest is practically as trou- blesome, except in so far as it is affected by changes in managing the crop, as it was in 1895. In Mexico, where it has existed for a much longer period, it is apparently as plentiful as ever. Careful attention that has been paid to the study of parasites and diseases, as well as 19 temperatures unfavorable to the insect, has failed to reveal any pros- pect that it will ever be much less troublesome than now. ‘There will, nevertheless, be seasons from time to time in which the damage willbe much less than normal. Climatic conditions will undoubtedly cause temporary diminution of the numbers of the pest in certain localities. In Texas these conditions have given rise almost every year to the supposition on the part of the planters that the insects have died out. This was especially the case in the region between San Antonio and Beeville in 1900, and in the vicinity of Corpus Christi in 1903. Both these years followed a series of seasons in which there was much less.-than the normal rainfall; consequently not only had a great many of the weevils been killed, but the numbers had been diminished by reason of the very limited extent to which it -was possible to raise cotton. Both 1900 and 1903, however, were exceedingly favorable for cotton. Eariy planting was possible, and there was an abundance of rain throughout the season. The crop was so far advanced by the time the weevils became numerous that a very fair yield was made, although in neither of the cases was any top crop whatever produced. Whenever a series of years of scanty rainfall is followed by one of normal precipitation the weevil will temporarily be comparatively unimportant. The most disastrous seasons will be those in which the rainfall is excessive and planting unavoidably thrown late. In this connection it becomes of some interest to speculate as to the possibility that the weevil may eventually be carried outside of the United States and gain a foothold in other cotton-producing countries. The fact that the insect is rather rapidly adapting itself to conditions in the United States that are quite diverse from those of its native home leads to the supposition that it would experience but little difficulty in adapting itself to climatic conditions wherever cotton may be grown. This probability of the spread of the weevil outside of the United States is increased by the fact that cotton seed for planting purposes is frequently shipped from the United States to various parts of the globe, and that within the last few years various conditions have caused especial interest to be displayed in this matter. There is nothing whatever to prevent weevils that may happen to be sacked with cotton seed from being carried long distances on shipboard. In the semidormant condition in which they hibernate they have often been known to go longer without food than is ordinarily required for a freight shipment from Galveston to Cape Town. Although there are no truly cosmopolitan cotton insects, it seems likely that the boll weevil may eventually be more widely distributed than any other. 20 LIFE HISTORY. SUMMARY. The egg is deposited by the female weevil in a cavity formed by eat- ing into a square or boll. The egg hatches in a few days and the footless grub begins to feed, making a larger place for itself as it grows. During the course of its growth the larva sheds its skin at least three times, the third molt being at the formation of the pupa, which after a few days sheds its skin, whereupon the transformation becomes completed. These immature stages require on the average between two and three weeks. é > ’ + ee, = * o ; . My . - ‘ oe ; A ‘78 ah. » We ae ie Bul. 45, Div. of Entomology, U. S. Dept. of Agriculture. PLATE III. DEVELOPMENTAL STAGES AND WORK OF THE BOLL WEEVIL. Two boll weevils feeding on a square, natural size; fig. 14, egg isolated, 25 times natural ig. 15, full-grown larva in square, natural siz fig. 16, full-grown larva isolated, natural ‘ fig. 17, pupa, twice natural size; fig. 18, adult just transformed, natural size; fig. 19, large larvee in Jarge boll, two-thirds natural size; fig. 20, pupal cellin boll, broken open, twice natural size. (Original.) 25 LENGTH OF LARVAL STAGE. Most of the observations upon the larval stage were made between September 1 and December 15, 1902. The temperature prevailing dur- ing the first half of September was as high as is ordinarily experienced at Victoria during midsummer, and therefore the extremes of the average season may be considered as having been covered. The time of egg deposition was easily determined by exposing unin- fested squares in breeding cages containing active females. The time of hatching of the larva could only be found by opening the square, and it was so ascertained. The newly hatched larva was then placed in a small cavity made by lifting the covering on the side of a freshly picked square and removing one or two of the immature anthers. The coverings were then replaced as carefully as possible. Another disturbance was necessary to determine exactly the date of pupa- tion. Observations made in this way were checked by others using larvee which were allowed to go from egg deposition to pupation under natural conditions and without disturbance until the end of the larval stage was approximately reached. Since the sum of the times found for the various stages agrees approximately with the known length of the immature period in cases where no disturbance of normal conditions occurred, we may conclude that the periods found for the larval stage were approximately correct. Altogether 266 observations were recorded upon the length of this stage. The majority of the observations may be included in three groups, and when thus grouped they may be best considered in relation to the effective temperature. Table III presents a brief summary of these groups: TABLE III.—General results as to length of larval stage in squares. Mean | Average average | effective temper- | temper- ature. | ature. Number |} Average |of obser- | range of | vations. | stage. Period of examination. 1902. oR. is Days. SeplsemperiGitojOctoper'd 22.) 2. 2) <2 Senos nese oo ee ees 78.7 3bn7 195 6to 9 Deplonioe4r co tOLOCtOver 2h ane. asa eee oe ee 73.6 30.6 15 7 to 12 INovomperal toMaecemper 1a) fo ls St eis a 62.5 19.5 15 | 20to30 During the heat of summer the larval stage requires approximately one week. This time appears to hold so long as the mean average temperature remains above 75° F. As the temperature falls below that point there is a gradual increase in the length of this stage. The average total effective temperature required during hot weather by the larval stage is not far from 280° F. As development becomes retarded by colder weather the average total effective temperature required to complete it is much greater. _ These facts may be expressed in general by stating that during the hottest summer weather the length of this stage is somewhat less than 26 one week. Development becomes slower as the temperature falls, but does not cease altogether so long as cotton can live. Even frosts do not destroy larvee in the squares and bolls, and these may finish development during warmer weather after the frost has taken place. The length of the larval stage in bolls is asa rule much greater. If the boll falls when small the increase is: slight, but if an infested boll grows on to maturity the larval stage more than any other is much extended. Special observations upon the larval stage in bolls have not been made, but reckoning from the known length of the whole developmental period in maturing bolls we may conclude that the larval stage can not be less than six or seven weeks. PUPAL CELLS IN BOLLS. As the boll approaches maturity, the full-grown larva ceases to feed upon the drying and hardening tissues of seed and fiber. Its exere- ment, more or less mixed with lint, becomes firmly compacted, and in the drying which occurs the mass forms a cell of considerable firm- ness, within which pupation and the subsequent transformation to the adult take place (PI. III, fig. 20). These pupal cells frequently include a portion of the hull of a seed, but the writer has never found a large larva or a pupa entirely inclosed within a single cotton seed. The cells described are shorter and thicker than seeds, but in general appearance there is considerable resemblance between them (Pl. XT, fig. 44). Doubtless these cells have misled some into the statement that they have found weevils in cotton seeds. PUPATION: The formation of the adult appendages has gone a good way before the last larval skin is cast. The wing pads appear to be nearly half their ultimate size. The formation of the legs is also distinetly marked, and the old head shield appears to be pushed down upon the ventral side of the thorax by the gradual elongation of the forming proboscis. Finally the tension becomes so great that the tightly stretched skin is ruptured over the vertex of the head, and it is then gradually east off, revealing the delicate white pupa. The cast skin frequently remains for some time attached to the tip of the abdomen. THE PUPA. When this stage is first entered the insect isa very delicate object both in appearance and in reality. Its color is either pearly white or cream. The sheaths for the adult appendages are fully formed at the beginning of the stage and no subsequent changes are apparent except in color (PI. I, figs. 5and 6). The eyes first become black, then the proboscis, elytra, and femora become brownish and darker than the other parts (Pl. II, fig. 17). 27 The final molt requires about thirty minutes. The skin splits open over the front of the head and slips down along the proboscis and back over the prothorax: The skin clings to the antennz and the tip of the proboscis till after the dorsum has been uncovered and the legs kicked free. Then by violently pulling upon the skin with the fore legs first the tip of the snout and then the antenne are freed, and finally the shrunken and crumpled old skin is kicked off the tip of the abdomen by the hind legs. LENGTH OF PUPAL STAGE. The length of this stage is more easily determined than that of any other. It seemed to make little difference in the time whether the pupze were allowed to remain in the squares-or removed therefrom. Considerable variation in the length of this stage exists among indi- viduals of the same generation and even between offspring of the same female and from eggs laid on the same day. ‘The period of investigation ranged from July to December, so that the extremes of the seasonareinecluded. Altogether over 450 observations were made upon the length of this stage. Nearly all of these are included in Table IV, which shows a summary of the results. TasLE TV.—Tabular arrangement of observations upon the length of pupal stage in squares. e Range in Average} Total Number Average | vee 432 Altes Period of examination. of obser- Jeneth length . ffectiv = effec “thy S vations. | Of PUpal| of stage. tempera-|tempera- stage. ture. ture. 1902. Days. Days. Oris adil Pb yAGiOlole nese oc eee nt oo ccecees h olees cate 161 2to 5 3.5 39. 65 138.8 Beptemper-1)tolOctober a. 2<=— == =- 22 ee 81 3to 7 5.2 36. 05 187.5 September 24 to October 28 . .__.-.-..-_.-...------ 167 4to 8 6.0 31.1 186.1 DEAT STAM PST OO pals pe ee 29 5 to 6 5.6 26.2 146.7 1D Serta Oe) Hea ey) aay I ee ie Se ae ee ee | 4) 10 to 16 14.5 18.55 269.0 It should be noted in connection with Table IV that the observa- tions made in November were during a period of rather warih weather and that the temperature records for that time are incomplete. It is likely that the average effective temperature given for that period might be different were the records complete. The average length of this period during hot weather is from three to four days, and the period increases as the cool fall weather approaches to a maximum of about fifteen days. A comparison of Tables I, III, and IV shows that the decrease in temperature affects each stage in very nearly the same proportion. In each case the maximum recorded length of any stage is about four times its minimum, and the great retardation in each case occurs somewhere between 60° and 70° F. of mean average temperature, or 17° to 27° F. of effective temperature. Even greater retardation occurs during the winter season. 28 The length of the pupal stage in large bolls has not been deter- mined. It appears to be longer than in squares, but it certainly can not occupy the same proportional part of the entire developmental period that it does in squares. EFFECT OF BURYING SQUARES UPON PUPATION AND THE ESCAPE OF ADULTS. The experiments made upon this point were designed to ascertain the value, if any, in the plowing under of squares as a means of destroying the larvee and pupe infesting them. But few experiments seemed necessary to demonstrate the futility of this operation alone as a means of controlling the weevil. Squares which were known to be infested with about half-grown larvee were placed in glass jars and covered with several inches of quite dry and fairly well pulverized earth. When examination was made it was found that pupation had taken place normally while the squares were buried under from 2 to 5 inches of dirt. In no ease was pupation prevented, though a few weevils did not leave the squares after having become adult. Altogether about 100 squares were thus buried, and from them over 75 weevils emerged. In a portion of the preceding tests careful examination was made to ascertain how far toward the surface the newly emerged weevils had sueceeded in getting before they perished. It should be noted that these weevils had never fed, and they would have, therefore, less strength and endurance than such fully hardened adults as might be buried in the ordinary processes of field cultivation. Furthermore, the soil used was of finer texture and more compactly settled than it would be in the field. Twenty-seven weevils were found in this exam- ination, their location varying from the bottom of the jar to their having escaped through 4 inches of_soil. A weighted average shows, however, that each weevil had made its way upward through 2 inches of dirt. Wemay infer, therefore, that had these squares been buried under less than 2 inches of fairly well pulverized earth, as would be the case from field cultivation, but a small percentage of them would have failed to make their way out. ) 94 | 93 | 92] 95 Octoberies aes ee Sie a Iel ce 94 | 94 | 90 | 96 | 93) 947) 92 | 92 | 95 | 99 | 94 | 96 | 92 | 87 | 86 October ee 24 ee) oe 5555 ae 95 | 91 | 89 | 98 | 94) 91 | 97 | 90 | 97 | 95 | 97 | 93 | 96 | 97 | 97 90 TABLE XXIV.—Study of the infestation of cotton fields at Calvert, Tex.—Cont’d. Block. Average infesta- Time of record. tion for Climatic conditions. . 53 54 55 56 | entire 34 blocks. Per cent. 62 58.88 | Rainfall in July, 1903, 8.61 inches (or nearly four times normal rainfall); Aug. 1 to 15, nearly normal rainfall (0.79inch, Aug. 2). Average temperature, July, 85° F.; Aug. 1 to 15, 851° PF. 97 91.41 | Rainfall from Aug. 15 to Sept. 2, 0.9 inch (nearly normal). Average temperature, | August 15-17_-___- 64 69 67 | | | | | | same period, 844° F. | | | September 2-4.____ 89 94 90 | September 14-17...) 91 96 97 95 93.20 | Rainfall from Sept. 2 to 14, 0.8inch (about Secred normal). Average temperature, ° 831° FB, 89 91.56 | Rainfall from Sept. 14 to Oct. 1, 0.14 inch (about one-tenth normal). Average tem- perature, 763° F. October 22-24 ...--| 95 99 98 95 93.67 | Rainfall from Oct. 1 to 22, 3.63 inches (more than two times normal). Average tem- perature, 74° F. October 1-3:--2--- 78 92 88 | Still another series of observations made by Doctor Morrill, at Austin, Tex., shows that similar conditions prevailed in localities nearly 100 miles apart. For each of these percentages 300 squares were exam- ined, thus making 14,400 observations in the series. ~ TaBLE XXV.—Study of the infestation of cotton fields at Austin, Tex. Block. Time of record. ae 1 2 3 4 5 6 7 8 9 10 11 12 1903. JATIUISTAEY Soe ee eens 29.0 | 34.0 | 11.0 | 15.0 | 10.0] 9.0} 19.0 | 33.0 | 43.0 | 43.0) 36.0} 31.0 September 7-9 ________-- 95.3 | 95.0 | 95.3 | 96.7 | 92.7 | 87.3 | 95.0 | 96.7 | 96.7 | 96.7 | 95.3) 93.7 October =i... ee 90.3 | 88.0 | 90.3 | 90.0 | 94.7 | 85.3 | 92.0 | 92.0 | 96.0 | 96.0] 92.7 | 96.0 Block. Average infesta- Time of record. | tion, Se Climatic conditions. 13 14 15 16 tire 16 4 1 blocks. 1903. : Per cent. CU OTIS) ete ene 33.0 | 36.0 | 49.0 | 55.0 30.37 | July rainfall, 12.65 inches (above nor- mal 1035 inches). Mean average temperature, July, 82.6° F. September 7-9 ___._.__-- 93.7 | 98.0 | 98.3 | 97.7 95.25 | August rainfall, 0.79 inch (below normal 1.64 inch). Mean average temperature, 82.6° F. October 5-7_....--- me ae 92.0 | 89.3 | 92.7 | 92.7 91.87 | September rainfall, trace (below nor- mal 3.72 inches). Mean average temperature, 76° F. : As the first records at Austin were made about ten days earlier than were those at Calvert, they serve to show a much greater total increase in the average infestation during August, though the average daily increase in the percentage of infestation agrees very closely in the two localities, being 1.8 per cent at Calvert and 1.9 per cent at Austin. A decrease in square production accompanies the maturity of the bulk of the crop, owing to the fact that the assimilative power of the 91 plant is largely consumed in maturing seed. Dry weather normally occurring at this period also causes a decrease in the number of weevils present. Not only are there less squares to become infested, but each square is also subjected to greater injury, and many which would otherwise have produced weevils are unfitted as food for the larvee by the decay which follows the numerous punctures. Several eges may be deposited in one square, but as a rule only one weevil will result. At this season weevils turn their attention to young bolls upon which the injury previous to this time has been comparatively slight. It was found in one ease that 35 or 40 per cent of the bolls were infested, while 15 per cent of the squares were yet clean. The longer period of development required by larve in bolls also serves to decrease the number of weevils produced. While the actual number of weevils begins to decrease within a skort time after the period of maximum infestation is reached, the apparent numbers may possibly be greater. The decreased number of squares serves to concentrate the weevils upon those remaining, and therefore the number of weevils found in any square will be so much the greater. RELATION OF WEEVILS TO ‘‘TOP CROP.” The hope of gathering a top crop is the ‘‘ will-o’-the-wisp” of cotton planters. After considerable cotton has been matured fall rains often stimulate the production of a large number of squares, and many planters are misled by the hope of gathering a large top crop from this growth. The joints of the plant are short, and the squares are formed rapidly and near together. Though weevils may have been exceedingly numerous in the field, their numbers will have become so decreased in the manner described under the preceding heading that they can rarely keep up with the production of squares at this period of rapid growth. Many blooms may appear, and the hope of a large top crop increases. The fact, however, as stated by prominent growers, is that before the appearance of the weevil they actually gathered only about three top crops in 25 years. The chance of its development, though always small, becomes hopeless wherever the weevil is present in consider- able numbers. (See Tables XXIII, XXIV, and XXV, and average of infestation of entire fields, p. 88.) Neither the hopelessness of gath- ering a top crop nor the actual injury which is being done to the crop of the succeeding year by allowing that growth to continue until frost kills it is generally appreciated by planters. Because of the apparent abundance of squares and the presence of many blooms the plants are allowed to stand long after they might otherwise have been destroyed. As is the case in the early spring, however, the apun- dance of squares increases greatly the production of weevils; and though a few bolls may set, they are almost certain to become infested before they reach maturity. Every condition, therefore, contributes 92 to the production of an immense number of weevils very late in the season and at just the right time for their successful hibernation. As the result of this, far greater injury is done to the crop of the following season, with a comparatively small gain in the yield of the present season. Furthermore, plants standing until frosts kill them are often allowed to stand throughout the remainder of the winter, and these furnish an abundance of favorable hibernating places for the weevils. The consequence of this practice is that so many weevils are carried through the winter alive that the yield of the next year will be much less than what it might have been but for the farmer’s indulgence of the forlorn hope of a top crop. From these considerations it seems plain that within the weevil ter- ritory all hope of a top crop must be given up and the destruction of the stalks be practiced as early in the fall as may be possible. This practice is one of the essential elements in the successful control of the weevil. SOME REASONS FOR EARLY DESTRUCTION OF STALKS. It is naturally impossible to fix any date for the destruction of stalks which would apply to all localities and under all conditions. The condition of the soil must be considered as well as that of the maturity of the crop. While the condition of the soil can not be changed, the time of the maturity of the crop is largely within the control of the planter, since by early planting of early maturing varieties nearly the entire yield may be matured before the usual time of picking of the first cotton from native seed. Whatever the qualifications which must be made, they do not decrease the general strength of the reasons which may be given for the early destruction of stalks. The principal reasons are three in number: First, the absolute prevention of development of a multitude of weevils which would become adult within a few weeks of hibernation time. The destruction of the immature stages of weevils already present in infested squares is surely accomplished, while the further growth of squares which may become later infested is also prevented. This stops immediately the development of weevils which would nor- mally hibernate successfully, and by decreasing the number of wee- vils which will emerge in the spring the chances of a good crop for the following season are greatly increased. The second reason is that by a proper manipulation of the stalks a very great majority of the weevils which are already adult can be destroyed. One of the most successful practices is to throw the staiks in windrows, and as soon as they have become sufficiently dry they may be burned. If the weather is favorable, the burning may take place in about two weeks, and many of the weevils will not have left the cotton stalks by that time. In ease rains delay the drying it will be found advantageous to expedite burning by the use of crude petro- — 93 leum. Grazing the fields with cattle, as some have recommended, will destroy much of the growth and prevent further development of weevils, but it allows enough of foliage to remain to sustain the life of many which are already adult until it becomes sufficiently cold for them to hibernate. Not only does burning destroy most of the wee- vils, but it also destroys the shelter which might be afforded the few that would escape, and the chances of successful hibernation are largely decreased by this practice. The third reason may be found in the fact that the clearing of the ground renders possible a deep fall plowing. This catches such wee- vils as might still be in squares on the ground. The ground becomes clean by this practice, so that no vestige of the food plant remains, and living weevils, if by any possibility they have escaped thus far, must either starve or perish from exposure. Furthermore, fali plow- ing places the ground in the best possible condition and makes it ready for immediate working as early as planting may begin in the spring, thereby saving delay in the starting of the crop. As stalks must be destroyed in some way before the field can be replanted, the practices here mentioned will not add greatly to the cost of destruc- tion. Even if some cotton is present upon the stalks at the time of their destruction, this small item is hardly worthy of consideration in comparison with the greatly increased crop and the more early matur- ing and better quality of staple which may be obtained by the adop- tion of this recommendation. Having studied carefully the methods of weevil control which have heretofore been recommended, the writers firmly believe that the destruction of the stalks in the early fall is the most effective method known of actually reducing the numbers of the weevil. Early destrue- tion will cost but a small fraction of the expense necessary to the fre- quent picking up of the squares infested by hibernated weevils in the spring, and is far more thorough as a means of reducing the numbers of the weevil than is the practice of picking hibernated weeyils from the young plants. Early destruction of the stalks is essential to the greatest success of any system of controlling this pest. All other practices recom- mended—early planting of early maturing varieties, thorough culti- vation, fertilization, etc. (see p. 112)—though very valuable in securing the crop, are perhaps of greatest value because they prepare the way for this early destruction which so reduces the actual number of wee- vils hibernating successfully that the other recommendations may yield their best results. Since the earliest investigations made by this Division upon the boll weevil, it has been recognized that this prac- tice is of the first importance, and the experience of recent years has but added certainty to this conviction. Planters have, however, been slow to change their methods of cultivation, but enough have adopted the recommendation to prove its efficiency. It must not be thought 94 that the procuring of the immediate crop is the only desideratum. Early and complete destruction of stalks is undoubtedly the most important single element insuring success for the subsequent year. DISSEMINATION. Two principal periods of dissemination may be found during a sea- son. The first is when the hibernated weevils leave their winter quarters and go in search of food. Having found food, the spread is mainly controlled by the limitation of the food supply. So long as an abundance of growing tips or of clean squares is near at hand weevils will not travel far, but when the condition of total infestation is reached the period of greatest dissemination is also attained. In any given field dissemination takes place mainly by the short flights and crawling of the weevils. The search of the female for unin- fested squares “is the principal factor in their movement. Heavy winds seem to be of comparatively small importance, as weevils do not take flight readily at such times; but light, warm breezes, such as prevail throughout the coast country of Texas, undoubtedly tend to earry them in a general northerly direction, and the continuous equi- noctial storms of the fall in Texas, occurring at the very time the pests are most active, have undoubtedly had a strong effect in the same direction. The two principal lines of spread will be found along railways and water courses. Between localities separated by short distances, traffic along highways is probably the chief factor. The distance which a weevil may travel in flight has never been determined, but from a study of their habits of flight it would seem to be comparatively short. Floods and the motion of water along water courses frequently serve to distribute many weevils along the edge of high-water mark. As river valleys are largely devoted to cotton culture, this would seem to be no small factor in the transportation of the weevils. Over longer distances the usual means of commercial traffic must be held responsible. Shipments of cotton, whether for ginning or in baled condition, are likely to carry many weevils. Shipments of seed for planting, coming from infested localities, are almost certain to earry weevils, and shipments of seed to oil mills may also assist in scattering them. The pests are often carried far outside of infested regions in the shipment of seed to northern oil mills. From the mills they are carried to the farms in the hulls or other by-products used for feeding cattle. Many of the isolated colonies in northern 'lexas originated in this manner. WEEVILS IN SEED HOUSES AT GINNERIES. Careful observations made by Mr. Schwarz at Victoria throughout the winter of 1901-2 revealed great numbers of weevils about the gins. They occurred especially in the seed houses, and the danger of the 95 transportation of the pests from one locality to another was most evident. A casual examination of the dirt separators which are now in use in the more modern ginneries shows that immense numbers of weevils brought in from the fields are separated from the lint by these devices. Even where these separators are used, however, a short: search in the seed house will show that many weevils pass through alive.