CPO OOP SW OE OE wen ee we OEE ee aoatoha Te ofS eRaTE ECL “ancwtirt wieie etna 7 re al eres ’ . iterates ~ - oe - é . “ : e . 7 . , . : : i ; . . , loin D-hihdthaing paseo: re - og OLS ¥ = a ee SAE RS Sede dosnt erenerer ane re : : : 3 | os = . Ba vr wee errTe - Saad . promansnd Ne Se pence TE yy eee : wu" vvew Kui Neate veer = 2.252... sec ce hiec cece ee 23+ 525 eee ee eee eee eee 112 Time -of appearance of beetles In spring: - .../ 2-2 eee see ee eee eee 112 Relation of temperature to appearance of beetles.............---...-.-.-- 118 Occurrence cf beetles in orchards... 2.2 2322 eeeee ee eee 120 Number of generations annually : -\)..- So. eee 125 Beetles from emergence to hibernation 2 72-- -. --- = eee eee 127 Habemation.2-.:-t.2..0.< 5655 2-2 eee ee ee eee eee eee eee ee 129 Mortality of the curculio during hibernation................----..---5--- 132 Percentage of fruit punctured or infested by the plum curculio..............- 134 Natural enemies... ..-< + .s.2..c ogee ee an ee ee eee oe ee ee eee 139 Parasitic insects - . 2... 2.12.52 see sn eae ee eo eee eee eee 140 (Anaphes) Anaphoidea conotracheli Girault..............-.---------- 140 (Sigalphus) Triaspis cuneutionis Hikes. sae eee ee ee 142 (Sigalphus) Triaspis curculionis var. rufus Riley.......-.-..---------- 146 (Porizon) Thersilochus conotrachelivRuley. 6-~ 2s seer os aoe ee 147 (Bracon) Microbracon melliton Say oe - oak ease ee eee 148 Bracon: Qopsat Saye ee ee ee ee 148 Other hymenopterous/ parasites... 22.2.2 3o- eae oo ee = ee 148 Myiophasia-znea Wiedemann ...2.252 2032 en5- 6 de eee eee 149 Cholomyia inxquipes Bigot ...---- ic dius 7 StS cheat eae Se een ee 150 Pegomya fusciceps Lett. : ce eee ene ee ge 151 Predaceous tasects esac. 225.522 me SSeS eR Oe toe ee aoe ee eee 152 Fowls)and! birds as curculiodestroyersiear == ae fe oe eae eee 154 Remedial measures. .322 23... 5.5. cb es ae ee ee ee ee eee reece 155 Historical. 5.2662.56 bahcr0 see ie Seen eee ee eo ee ee eee 155 Premiums for remedies for the curculio. .. . - BR RP an oe aS agi 167 The Ransom:chipiprocess=s-e-eee eee ene aera Me Picata tes ise x 168 Jarring forthe ‘curcttlio:.. 225° 25255: ca22 soe ae ee eee See ee ee 168 Present.status: of jarring. 3s shee Stee co eee ame me seen a cree eee 172 Cultivation-for' destruction’ of pupae: Saco ce see ee ee eee 176 Spiayine wath arseniGals-: 30s 5 5-8 te oc cee Ge nee ce ee eee 178 Beading experiments ‘with poisOns: 0 ---.2cm- cece 8 = ee 185 Spisyine forthe curculio:on apple 2.25322. .-ceeece se - oe =- nee eee ee 189 Early experiments...7..26.2222 5 he Shae Sees seamen nee 189 Experiments by the Bureau of Entomology................--------- 193 Bzperimenta at Anderson’, (Mo:'/ S02. 2-2 6e- 22a re eee 193 Experiments in western New York and northwestern Pennsylvania. 195 Experiments at Siloam Springs, Arks.2--- -ts sc 0 te soe ee eee 196 Experiments my Virginia sssceee ss Ones ee a eee eee 197 Experiments:at.St..Joseph, Mo... 22.2d22 5. See See ee ee 198 Conclusidnsst .s2 356, eS sss at et ee eee . 200 Scheme forspraying apple orchards... -2- 922.22. ees ee ee 201 Spraying peaches’ with arsenicals.- <4. J... gee -2esc so el et 202 Some results of spraying peaches for the curculio..............------ 208 Directions for the preparation of self-boiled lime-sulphur wash. - ...-- 212 Directions forse arsenate of leadeessssseeee eee ee 213 Schedule of applications: .. ....:.-: 2. gece eee eee eee 214 Midseason iarleties:,-’. ....-- 9. 7h cee eee ee ee eee 214 Late varieties... 2... 0.235.422. ce See ee eee eee ere 214 Barly ‘varieties’: z 2% nec 35> > (oso Se eee eee 214 Spraying plums\and cherries... .......-.<...<--- eee ee eee ee 215 Some results of spraying plums: .\.. . .. Sess eeeeeeee ee eerie ae 216 Results of spraying cherries....¢ 22. 5. Soe see ee eee eee 218 Ficonomic bibliography < 222.222.2225 6.0 2.0 5 eee 219 foo ep: Cs eee agen eS Se Ape nn pee ee cee este es - knee a Ee ae es Sere 243 PuaTeE I. IT. 100 VIII: IX. XIII. XIV. ILEUSTRATIONS. PLATES. Page. Stages and work of the plum curculio. Fig. 1.—The adult or beetle, lateral aspect. Fig. 2.—Beetle, dorsal aspect. Fig. 3.—Larva. Fig. 4.—Pupa. Fig. 5.—Larva, or grub, and its work in cherry. Fig. 6.—Injury to ripe peach. Fig. 7.—Feeding punctures and Scars trom eee punctures.on apple. ........2. 4052s secsees Frontispiece. Work of plum curculio on plum. Fig. 1.—Egg and feeding punctures on young wild-goose plum. Fig. 2.—Nearly ripe wild plums, showing egg scars and gum exudation from feeding punctures... . . 32 Work of plum curculio on plum. Fig. 1.—Effect of egg and feeding punctures, with gum exudations, onripe Japanese plums. Fig. 2.— Wall feeding punctures onjiripe prumes!:* 2,20 2.2222 sss 2. 32 . Work of plum curculio on peach. Fig. 1.—The adult curculio on newly set peach. Fig. 2.—Curculio larva, or grub, and its work ED) Pail] 35190 (oe OU eRe aA a a OE EO A ES 36 . Work of plum curculio on peach. Fig. 1.—Wormy windfall peaches, Fig. 2.—Peaches deformed by egg and feeding punctures....-.. 36 . Work of plum curculio on peach. Fig. 1.—Deformed ripe peaches. Fig. 2.—Gum exudation from curculio punctures...............-- 36 . Work of plum curculio onapple. Fig. 1.—Egg and feeding punctures on youngapples. Fig. 2.—Egg punctures on apple some days old... 40 Work of plum curculio on apple. Fig. 1.—Young apples, showing scars from egg punctures. Fig. 2.—Ripe apples deformed and knotty from egg and feeding punctures of the curculio............ 40 Work of plum curculio on apple. Fig. 1.—Imperfectly developed apple from tree in which curculio grubs matured. Fig. 2.—Small drop apples in which curculio grubs matured. Fig. 3.—Nearly ripe summer apple from ground, showing extent of feeding by two BRIN CUEG AR SONG See ene cir are Serer ence mya aie tise SMe Swan eo oe 40 . Injury by plum curculio to pears. Knotty and deformed ripe pears resulting from egg and feeding punctures.................------ 44 . Plum curculio injury to cherries. Cherries cut open, showing the StH ABO AU WORKS 22... 22 sees ae eta ees tena ane eceas Gee A+ . Methods of study in plum-curculio investigation, Barnesville, Ga. Fig. 1.—Out-of-door house used in life-history work. Fig. 2.—Soil cages used in obtaining data on life of insect in ground.......... 48 The fall feeding punctures of the plum curculio on apple. Fig. 1.— Characteristic holes eaten into apple by the beetles in the fall. Fig. 2.—Feeding punctures of beetles on summer apples....---- 128 Jarring apparatus in use or recently in use against the plum curculio. Fig. 1.—A wheelbarrow curculio catcher used in New York State. Fig. 2.—Curculio catcher made by sheets on frames, in use a few WEARISe I CrOOllIS. < WAN XVIIT. XIX. XX. THE PLUM CURCULIO. Benefits of spraying apples for the plum curculio. Fig. 1.— Duchess apples from trees in unsprayed plat. Fig. 2.—Duchess apples from trees in plat sprayed against the plum curculio with arsenate-of lead =... ..... ...'.0-2 36.25 eae Conditions favoring the plum curculio. Fig. 1.—Native plum thicket in the south, adjacent to peach orchard. Fig. 2.—Woods and thicket adjacent to plum orchard, furnishing the beetles with excellent hibemation\quarters’)-5->+>5- 22> -eeee eee ee eee Effect of arsenical sprays on peach foilage, Arljngton Farm, Va. Fig. 1.—Unsprayed or check tree. Fig. 2.—Tree sprayed once with commercial arsenate of lead. Fig. 3—Tree sprayed once with homemade arsenate of lead. Fig. 4.—Tree sprayed once with Paris green. Fig. 5—Tree sprayed once with green arse- noid. Fig. 6.—Tree sprayed once with arsenic sulphid.......- Arsenical injury to fruit. Fig. 1—Elberta peach sprayed three times with arsenate of lead, showing burning and cracking effect of the poison. Fig. 2.—Japanese plums, showing burning from one application of arsenate:of leads )+ J. 7.22-5-225-seee see. ee Field experiments in Georgia for control of plum curculio and peach diseases. Fig. 1.—Gasoline power outfit in operation. Fig. 2.—Determining results of spraying, each peach being cut OPO ')5:54:2 vase he Sees eRe ee a ae en ee Size of peaches at time of first spraying with arsenate of lead, show- ing on the left the earliest and on the right the latest stages in development when this treatment should be given..........-.-- TEXT FIGURES. Fia. 1. Herbst’s figure of plum curculic, accompanying the original descrip- oD ? nV) oD oD 6.0 Wee 0 il AS 1 Ga eee mR aN “epee Be Boa A PO ae OE Seance, cae ee Bn 2. An early illustration of the plum curculio, frequently used between co about 1830'and TebOe ssc ec seco tea cee ate ae ama oe eee eras . Peck’s figure of the plum curculio, published with his description (CRhynchenasscenasy)) ami llSil 9 eae erecta eee eee eee . Map showing by the shaded area the distribution of the plum curculio. - 2 he plum. courer (Anthonomimus scitel laris) =m a= sae te erie a 5. The apple curculio (Anthonomus quadrigibbus)..--.-.-----+---------- 6 7 . The acorn weevil (Balaninus victoriensis)....-.--.------------------ 8. Fuller's rose beetle ( Pantomorus fullert) a2. 21 2255 52 as ee eee 9. Imbricated snout beetle (Epicexrus imbricatus)......-.-------------- 10. The plum curculio (Conotrachelus nenuphar): Egg...---.------------ 11. The plum curculio: Larva, showing structural details -..-.---------- 12. The plum curculio: Head of larva, with parts named.......--------- 13. The plum curculio: Head of larva, lateral aspect, with parts named. - 14. The plum curculio: Head of larva, ventral aspect, with parts named. . 15. The plum curculio: Lateral, dorsal, and ventral aspects of right man- dibleof larva, -wathunusecles: 225 .e50ee eee eee eee eee eee ee 16. The plum curculio: Dorsal aspect of maxilla and labium of larva, with Parts MAME <. <2. 6 66 oe cied a ote eee eee eee 17. The plum curculio: Pupa, showing structural details........--.------ 18. The plum curculio: Mouth parts of the adult...............--.----- 19. Black-knot of plum, showing, on the left, infestation by plum- curculio larvise '35)'|25-52 do... - Do. pmISOMe ee aot eee sacs ack connec tn tes 96: 130i\Res GOz-tes Do. VD (AT ETO LE eee A ee eee 98) 25 e322 d0nsc.. Do. ue eS Ve oe ae aes 99 45 | Absent.... ESI et Ps Sciacca sles Sims's a 100: 200/58. dos-. 2 Amarillo...... BE Se oe Cars occas 101. 45 |c2dois=:. | OKLAHOMA. JOG BTS We oe See eee 98 00 | Present...;| Specimens received from correspondent. AN Gee Sang cette tees asso aieis eee mses = 99 30 !...do.......' Reared from fruit in 1910. 24 THE PLUM CURCULIO. TaBLe I.— Western distribution of the plum curculio—Continued. Long‘tude Localities. (approxi- Occurrence. Remarks. mate). | KANSAS oO ; \O SIG RS: 33s Sane ee See oe ae 97 20) Present...} Reared from fruit in 1910. rete UERVEN St tes Si ey al ee ere ke 2 OSD sack Osseo ke Do. ELH in Sons tae ee a= ee Sete ae 98: 100) |z doses: Do. INGELONS 260 ke Soe coe ne eee 99 50 | Absent (?) CG ED ys Saree ta ene Syne eee 101 (002 Ga 12.2. 257 a 7S" Rees Ne Tod SLa PT fatale py il 7 a a Va Da 103 TiN ae 192| 186] 201| 234|/ 204| 140| 68] 371 31| 1/| 1,294 Maximum | Average Date of Days under, Days on No. of individual. tag laid. | death of | observa- | which eggs| Number of | number of beetles. tion. were laid. one day. per day. «it | i July 12 {70 78 | sal 27 5 2.67 it Paes a Aug. 10 eee ia ae I 54 8 3. 37 Lae ee July 14 {70 90 at 37 mH 5.16 1 2 eee Aug. 6 {sone 2 oh 5 mH 3.12 1. Oe Aug. 4 soc 2 i \ 49 8 3. 67 La oe ee fe do..... eee 7 aa 45 9 3.33 lovee. ha Aug. 8 ae. 4 i \ 58 10 4. 43 Sa ee: July 19 pea a st \ 29 9 3.55 In Table VI are given records of observations by Mr. Johnson in 1906 at North East, Pa. Beetles were obtained by jarring, and the pairs in copula placed in individual jelly glasses on May 22. The food was Japan plums. - 2 THE PLUM CURCULIO. TasBLE VI.—Egg-laying records from 10 plum curculios, North East, Pa., 1906. Eggs laid each week by each beetle. No. of individual. May June Total. May} 30- | June} June! June} 27- | July | July | July | July | Aug. 23-29. | June | 6-12. | 13-19./20-26. ous 4-10. |11-17. |18—24. |25-31.] 1-7. 5. c TER ia See Mee ae 9 12 14 8 7 1 Sie eae earn saeoe a Le 2 54 bob nye sre yalere ainin ave ee since weet 33 16 16 (ONE 1 4 6 Ga}e-eexe 1 90 Bectate en eaten pace eee 33 13 20 8 8 7 A SRS Sele Sac Se see | ee 93 NEES Gite Mette ie a See) 2 30 17 5 2 ee De| 00 as | eee | eee 62 [ROR ER eee as. USS 2) 2 3 30 11 7 7 2 3 3 Die wes 102 6osse See 2 56 25 22 9 al pete ares eee err! [ase 122 NN lo isl (Sins nt 6 16 8 7 7 2 ily Sc ate | eee 71 a ea eee Ae) Leta 1 24 12 6 4 3 A Se | erate) (Merce | Uy Sk Oe 66 9) oo cad eo eee se eae pence 3 28 12 7 be Baeerse 13 7 3 1 79 TOSS ee ee aes | ee Bt 7 1 1 AN nooo 9 12 Sie eee 48 Total® i= oso eee 81 183 197 94 54 48 18 66 36 8 2 787 Date last| Date of |Days under} Dayson | Sumber of | numberof No. of individual. Se IBAA death of | observa- | which eggs Bonen oops al 88 lac. | beetles. tion. were laid. aa any ss doy he trate 5. ae eee ae July 10 Weant ae e \ 30 6 1.80 1 1 14 Serene 12 a ht enna to Aug. 4 {Ae ops 298 |} 32 16 2.81 _jopeam el A hme oe Telyw ae et 32 15 2.91 July 13 52 ; UAE Ge oon en s HOSE OES no Tne eeme see July 14 ae 14 53 \ 26 6 2.40 INN oN FT) a July 26 AUB. 16 salt 37 ul 2.76 Aug. 13 83 6 ed July 2 Ge 16 86 \ 32 16 3. 81 141 123 aie SPR a DS Prod July 22 {juny Aa ae 34 4 2.09 July 18! 127 (HERE pope se cea Sac soscrsSoqae oars July 15 {july 262 2 65 \ 28 7 2. 36 Dore Peek een aug. 1 gee a | 35 6 2. 26 Ne aed eae Sn es ees ee July 26 {TY 35 AN 22 5 2.18 1 Male. 2 Female. In Table VII are records of eggs laid and of egg punctures by four pairs of beetles kept in the insectary at Washington in 1905. Taste VII.—Egg-laying records from 4 pairs of the plum curculio, Washington, D. C., 1905. EGGS LAID EACH WEEK BY EACH BEETLE. No. of pair. May | May . | 18-24 | 25-31. 109 60 65 8 242 June | June | June | June 8-14. | 15-21.) 22-28. dT. 40 44 37 32 153 128 June 29- July a: July | July | July 6-12. |13-19.| 90-96,| Total. LIFE HISTORY AND HABITS: THE EGG. 4 Taste VII.—L£gg-laying records from 4 1905—Continued. 43 pairs of the plum curculio, Washington, D. C., EGG PUNCTURES MADE EACH WEEK BY EACH BEETLE. | “ June i . May | May | May | June|June | June|June} 29- |July | July, July No. of pair. i1-17.| 18-94,| 95-31.| 1-7. | 8-14. | 15-21. 22-28,] July | 6-12. | 13-19. 20-26,| Total. 5. . 12! ss| 10] 4s| 51| 59| 67| 26] 19| 34] 2] 616 24 eee eee 77 54 70 52 41 44 1PM re rep tal eee Ne ttt lene oe 350 + at 6084555 Ree eeaeeos 61 65 61 39 16 25 274 ee be S54 beeenea Peace 289 |. -- Lot SaaS See 2 ol ll 13 28 Po | eee Jeceeec|ereeee|ereeee[eeeeeefeee ee: 131 ARG URN US See eee eae 301 218 254 167 136 128 101 26 19 34 | 2 1, 386 Average Nowof pair Date last | Date of death Days ander number of SONU egg laid. of beetles. Fiori eggs laid ‘ per day. Ul. 22.083 SSeS ee eee July 21 | Aug. 282...... 2110 4.95 f July 71 2 157 - oes ts ce nw eens s Smile wwielnwian se cle ashe ws June 26 eran a 257 \ 6.19 ERTL ei Sas oe 154 PR ee a alates aes 2 soe ne eins see eee see June 26 Apaty 625200 257 \ 4. 60 June 181_..... 139 ape ate Hee 8 a, a ea June 10 Ne dens ene 3 \ 3. 23 1 Male. 2 Female. The beetles were captured at Arundel, Md., on the 9th of May by jarring plum trees. All caught were inclosed together under a bell jar until May 11, when the pairs were separated and placed in indi- vidual jars. From three to five fresh plums were added at intervals of one to four days, and those taken out were carefully examined. After about June 10 apples and plums were used as most convenient. The insects were kept under a temperature considerably higher than out of doors, namely, in the insectary building. The prolificacy of these individuals is not greater on the whole than in the case of those observed at College Park (Table III), but the death of pairs 2, 3, and 4 was evidently hastened beyond what would occur under normal conditions. In every case more egg punctures were made than oviposited in, though the difference in the case of pairs 3 and 4 is less than with pairs 1 and 2. In the curculio egg record on peach, Myrtle, Ga., 1906 (Table VIII), the beetles were captured by jarring, April 5, and taken in copulation some hours later. Each pair was separately confined in a jar and supplied with peaches until July 25. As all peaches had been gath- ered from the trees by this date, foliage was supplied subsequently, which fact no doubt hastened their death, as most individuals died within a few days. 44 THE PLUM CURCULIO. TaBLeE VIII.—Egg-laying records from 9 plum curculios, Myrtle, Ga., 1906. Eggs laid each week by each beetle. os ] “i iadividusl alt ile Alen tere alll alge ae No. of individual. oi = 4 = E S x = : 3 5 5 5 = 2 4 SPE STS | | Sy ee Sees eel eae Pe) (rte bet yea fer Pell i= ssi fedzyed fel ey PT eat SSN Ss less || Sx alalalalealaela|awei al sl|sl/se/ay/e2/2/2I/8s siai—a aS (SS eye ie We ee ee 1 4.1) Sr |(25:)" 6) orl) eth 16a ecg) ea ae ea ct On eee eee | eee 100 2. Sheet: Gall san| cel: soe po Selene loeppateeret pee sae Al 13 | 10 | 38 | 20 | 24] 13 | 11 2 2 2 8 dee Fn) (ae 8 iW ee TTS Hl 2) Umea Ga) Wi ae ee oe Pee a erlie 2 eyel eeele ae ee ore ene eel | eee | eee |e 624 GAL 4 Se Si LT | Seal Pea a eer FS ice 8 7 a'83 (eee 4 a lesasleoeeleeere 82. 13 ‘D) sep 3 M Vestelke oale ook hea leeee ieee 9 PA || 6a BOR SH 23.) 201) LO) ss) Bae eo 62 | 41 |176 | 50 | 83 | 48 | 40 | 33 | 18 | 10 | 40 Date last Date of | Days under Risin No. of individual. Som inid death of | observa- aes WAG 88 ta1C. | beetles. tion. a oe May 181 1 43 SE eae ee So nme eka A Os nS July 4 (July 353 | aie \ 3.57 uly 291) 1115 Die slat ures Buln too 2h! 0 eM RN ce eee May 7 \{ju,7p a ral; 1.55 Aug. 11 1118 URN ET a ene ee ed 6 nas RR cD NPS TEN, June 22 {june26 2 aS \ 5.31 July 241) 1110 Be 2 cig e eee snes eee ec ee ckc oe sees som Acme e maces eee June 6 \suly 26 2 | 2112 \ 3. 53 uly 201 1106 56 Sh Saon as orenc dese esone sneer sree sacs senbaacess one aosscsessassneags if 1 ®) a \ 1.00 uly Be des chat ease ai TS be aoe 5s Oe ee June 22 (a, al bie | 4.04 une 21) 158 ; ne RTE ee Peer tut e ECN EO OY oe June 1 Hy ine96 | 280 | 2.26 Rr tte en. MEA eS Te ee May 16 Ae age | PH 3.82 Aug.101) 1127 Don neo Sias ee wens 2 nj en a ene oe oe ee nn eee eee July 25 Withee 2128 5. 81 1 Male. 2 Female. Comprehensive records were obtained at Siloam Springs, Ark., during the season of 1908 (see Table IX). Curculios were jarred from plum trees April 17 and the same day 30 pairs were selected and sepa- rately confined in jars. The beetles were given fresh plums daily as long as plums were available, after which apples were used. Obser- vations were made daily. PLATE X. Bul. 103, Bureau of Entomology, U. S. Dept. of Agriculture. ( [eur 2 ol IQ) 5 ainjound Ssutpsey pue 33a WoIy Sul[Nsed saved adi pauioy "SYVad OL OIINOYND WNO1d Ad AYNPN| ap pus A}jouxy Bul. 103, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XI. PLUM CURCULIO INJURY TO CHERRIES. CHERRIES CUT OPEN, SHOWING THE GRUB AND ITS WORK. (ORIGINAL.) LIFE HISTORY AND HABITS: THE EGG, 45 TaBLE 1X.—Egqq-laying records from 80 plum curculios, Siloam Springs, Ark., 1908. Number of eggs laid each week by each beetle. 1S ) =i he Ca eae ss ieeala: Ble Bae: Movotmewieme HSS ls (SIPS | aa ls lela | f Ree alee ee ee ha Ie foe ee Ty Bie eve | itest pesca lteltasts | erern |pecraa It eer nil iieel ins isis) hips bso ll teo7l ep) || ee Al/AlSsl ales Milogcaaiei los | Sets 6 2)2|2/2 2/82 F/2/2/2/2/2/2/2/2/2) 2 ‘5.85 g Oe eee PLO) AGHNSL, | ee2N TSH Lon 2on ee eon male 2: |e oe les sels 5 213 Re a fae ed Bo 2 5) LS elit) S85) 40 ata) 27a L6ae ta eeB hts) | ess Dc eck. tea..| 281 ee Seas cece 15 | 19 | 13 | 44 | 41 | 35 | 44 | 33 | 29 | 21 | 21) 14] 29/11) 9] 7] 8 388 22S 5ee ge eee eee INT ph ale fa a i Ua Wh a 2 iB A 3 MSH a Gols Sal Tay Ug ok: a To i el [eee ees peal) eis Meee So eet lace a TES OSS Pay UO eee cel ones moda ened sate lege ea-llae el anor eee 77 Gee oid sacs cae 'sicls.s | 12)) 87 || 12) 40 |\'45 | 42) | 37) 238) 1/25) 20 14) Ws) 6) 1 309 «J 4aS SSA eee | 12 | 15 | 16 | 26 | 27 | 20'| 27 | 22) 23) 14) 16) 11) 4) 8| 4). 245 Beivcekictetesk css 5ee% Peet Ou berve le Gn|/eOnlel7, Bod edse Hose SeaSl sence occ Spee mscet cnt 66 OL SAS ee eee V2! RON Te ES r Qa ag Be aeeigeeel eee sae see | eee eee 59 LS Ee ee eee | 15 | 20 | 17 | 34 | 24 | 22 LE ART Na ee sees eee leo 268 1 ah rene set by 8a) TE 25) 13 | 16 Bale 21 |Rane| socal Poets le 83 1 alee eee | 12! 18 | 21 | 31 | 24 | 19 Je es ee Se PN ihe a 155 Lee ee 4) 4/11) 19 | 14) 19 sc (acs DY eel Nl VCS a gn pes ee 132 1 SES a aa TA ei) eae fall Sane|=see|s-5- eA eeesl teed tase 108 Boeeen ene Sansone see = 16°| 9) 5 | 19°) 19) 19 2 |S a| aon etal Seaver escn etecte 120 Perea nasi sOose Ss san 23) oa 29) leak | ps3 As |poalieas|atecloccs| Pi Seinc|(s 109 Pe React c cae ceeck cot (Gal LS a jase 30) aeMeR2o 0] LOM 2RIEy Age 18 | June 24 dW Hata | fia] we SEF Ne 14 | June 25 Aa LOE | Mees |e 22 | June 26 CoN ales |e 2 36 | June 27 28) 7 1 38 ; June 28} 3 | 24} 11 |. 33 | June 29} 11 Tee 37 | June 30 BY (al eel here soe ors 647 FTO Ge oios see) Snake aro. eet eae oot lef ree eee ore r na AS || DULL Yi | Sorell ee daa | eee eee 22 Nitty aoa | kon | aoa see eee 12 \naly, Ais a ees Pe ae eee PAE aie Ny aemmenaye| ome |e atom iret) Serep Be ea e 1G) ABU GTS el beep LED) | eel TRH] Mualiys Tl A Dit ZN et TG |) ait “ASSL 1 | Ep 30| July 9 | ROSH MOM Preece |S 40 | July 10 aH2Ou E20 Mle |e al So aE Etoile |e ever | 10 | July 11 Sil cereal CO Sos laecialeeoeaeer (ener TS] dsl: = el Seen IO ees ees | evened | erect | antes eters 16 | July 14 2 BL Nite se | eh clleea al See eree alae 14a Oubyets yy Ga esse |e Or ru saat | betel e rota eee Si ate livg wivenl ere meee BT Ve Ae bs eee al Ler Gal dialyeet See ae soe Sele ss] Sk [Gare SIC abel sata ee 8 | July 19 Beet ee alo gees aa ae 2a ee 8 | July 21 Ga eae leeters) ees) bones Beene Sel esse 8 | July 22 bie eae pees enon Geen tees) Fenc Isarsc 10 | July 23 By) 6 ise See oe eee |e rere es e Di Lye 26) |e esee Bees lisa fees! | ae eae ON Fully 28s ie. alee Oa selsr Slade '.o avon eer 297 Totall..3. 26 J nenss oe eee eae a aseaneee Average length of egg: stage for June: 3: 2. = ace- or See ee ati Slee oer ereia ee eee days.. 6.20 Average iength of ege stapedor Uiliyics5- ee a ee ee ele tele oe late do.... 5.61 Average length of ege stage for Juneand July. 2 ~~ <6 se eciem ae ele ce omnia niall erent rs do.... 6.02 LIFE HISTORY AND HABITS: THE EGG. 53 At Barnesville, Ga., during 1910 the length of the egg stage under out-of-doors conditions was determined for different lots of eggs, during April, May, June, and July, including a total of 445 eggs, all as shown in Table XVII. Taste XVII.—Length of egg stage of the plum curculio, Barnesville, Ga., 1910. Eggs Date Eggs hatching in specified days from deposition. Seciar Total obser- d iti ' dann vation | ©CPOStMon. | 3/33] 4 | 441 5 [54] 6 [64] 7/73] 8184] 9 | 94 | 10/103| 11/113] 12 }123| 13 |134] C295: BenleAprs 8 Jess |b=2 Say ee) ewe a pe (ae Ree AO A Fel cate eel Le a eases | ey ene 262.5 ot |] hye 91] RN a DV ee | a Tn 0 3 1a | tf | ee ee | Shika Sale ssik0 aye yey oes I a bills eee Re Loe salen |S Salles Ro eadd ote | Me oes 1,018.5 169 inntaleweme ase sees eee EE Bee pi tece tik OPE? Se Leet pene fos 1, 662.0 | 10 | May si] otal ol eS ee ers | Cate | 1 7 Soy eee sey ca nee eee Per ta De 85.0 Chg Ree 20) || fete Pe ane S90 el Re rs Fl eS ee ee eel Se bern Poe [ee 110.5 19 | May 112) | be (SF bese. |e Be(LON| byl see] 2. Seer os eel eee lio soe aoe |e stl eye 140.5 ht be Eh Wy ee Ve are 2 Ee eee | Recce| at | eat eck | ee | | ese | ed | seal [sl Sea tall anon 10.0 3 [LIE i pee ee 3 5 oye | eae (See ee eae Es eral eel (epee ea aes 1355 14] May 19 |...|_.. ALS |R2 ie | Pa ca Ph | tJ Fil Fae ATL (aU a a Ve 52.0 32 | May PATS eae 241315 MG oe loea| |S Sollssolees| alee Baa Bao Bees lel sel eto) ese lace 134.5 PaeMaY asl calescleece US at | ee Lees age SS eye el eee ese bse (res need tee ees (ee 10.5 Pan May | 625.5 ile. ASTROS! | os ee ee esa avec eoelbsaleeolsss Pealad cast oe eee 61.0 45 | May 26|...|.-- Tl fal eee | Wee | iON (ea [P| Via 2 eae [eFC | el RE 198. 0 Ua 6°27 ae Aber = | fa 1 beds tol eet ee Fae ete eee (as aes mae ce | ee aes (ore 49.5 a 165 BR atall see oe Ste ae ae el Be i go Na BAC et one ae ee secese -| 875.0 _——. | |. { 1|June 16]. 11 fe (| Ie P| [rele esp) acct foses| es eel Pee ese eee] Pace eases nes Bin) Pen EPCLTIOMmNP ITE Le Reese aCe eal | ac lses|| solos | scieleea|ee lease aula Soloce 3.0 3 | June 18]. Ty (7 eM TE fee ie el Me = ee el eee : : 15: 2!June 20}. 1 TA joa | [or eV a |e Wa a Pr 8) Ln (ee [ee | : a 8.0 i} faune 22)" le 1 Hells |e ss | FSF [oe Fee F B14) 1} June = 23 |}. I eee | ire (| [eee | re SEA es Se Nee - 4.0 ae oume, 9245412) |as.|- 52 Se lS el |e a le Se aes rele ees) |e a [ene (ee) Pee 2 Ae cre 6.0 = | [eA weaYs yee Os (OR (RD) cs WE Aer | ee (ieee Fe By a esl Pee 3 11.0 Dale eenere O27) | mies ies | ole eee | es al ee ee Ee 2 DALE) 2| June 28) 1 Mees eee e oe] we ol eee 3 eo oe ee 2 7.0 5 June 29° }5..) 4 BML sel anal sere d 5 sar eral eee Ele 22.0 Da une, (SOL iad alle =| Bet | Ae SNe | eal ern feete | eee eee a | pene ne hae SS ae | i 1 ‘aa Saat Soa cot \ ) | 28 EUS ola a ea ic as pele aay tae AGN etre evens wen} 104.5 1 | July Th see EP | tt A Vie 6 Sa St SS eh ae a eee Dire eel epee (ee 4.0 2| July Saeess| en | eee | es ea pe | EE | (OR VR Vy eo (ee (La 9.0 Spill Tipe ©, < EEA EM Mio eel Ted WW | 2 ee (Vl Fe 8 | Vee Fea ee [em a 8.0 17 | July BM WiGules | se “Be a el Sree bed | Jee Sse eat lec eed abe See tec eae sere 54.0 18 | July Calees: 4 22 Al eet | | 7 ei (es ae | tad (aa (ce bere 64.5 ol ILE cB Mt 2.38) Va Bl TR | le 25 Bd bevel pe Nee |e (Eat (SRT spl (el J 2 (ees Den ef 27.0 6 | saly 141) 4 2102 «ATE alli ee = fcc al ed a fa fe iW 19.0 10 | July 15 Lat eee ar a Va ceed S| Seal | orl Ee at ee ee ee Te 40.0 ROM Jat y, Sasha 614 BS pe | fee er EAU Se De a ge De re | 47.0 8| July 20 tT Fi al 2 Fs) Fa (See Hae | (eae er ee ee 33.5 Seal Gan a aay Patel Spann atl Soa alan spicata alt oa Lae, lanes Gs OL Set 83 SURE te are rate oes es Sr Ee Rta Sit Ac eR ING Sane ch tt ia ck ae 306. 0 Average length of egg stage for April ................- . 83 Average length of egg stage for May... 30 Average length of egg stage for June... . Sina Average length of egg stage for July.....-- . 68 PEI o een Onere Stave Ol: SOUSOLA smi ac,at aoe ais. onye. case ceeict auch aoe Saseee cer sees 62 The gradual decrease in the length of the egg stage following the rising temperature is well shown, dropping from the average, 9.83 days, for April to 3.68 days for July. The average for the four months is 6.62 days. Table XVIIT gives a summary of the preceding data. There is seen to be a range of from 24 days to 134 days for the different localities, the averages varying from 3.77 to 9.23 days. 54 THE PLUM CURCULIO. TasLe XVIII.—Length of egg stage of the plum curculio, various localities. [From preceding tables. ] Eggs ob- | Minimum | Maximum | Average Localities and years. Sail. period. period. period. Remarks. Days. Days Days. Washington, D. C., 1905..... 247 2.50 ‘ 3.77 | Eggs kept in insectary. Myrtle, Gas, 19065. 2-2. one 140 2.75 6.75 4.44 | Eggs kept indoors. New Richmond, Ohio, 1907.. 113 3.25 6.25 4.92 Do. Washington, D. C., 1908. ...-. 45 7.75 11.00 9.23 | Eggs kept out of doors. Siloam Springs, Ark., 1908... 18 3.50 6. 00 4.66 | Eggs kept indoors. Douglas, Mich., 1910.......-.- 944 3.00 12.00 6.02 | Eggs kept out of doors. Barnesville, Ga., 1910.......-. 445 3.00 13. 50 6. 62 Do. THE LARVA. HABITS OF LARVZ JUST HATCHED AND COURSE TAKEN IN FRUIT. After making its escape from the egg, the little curculio larva usually remains for a short period in the egg cavity before boring into the fruit. In a comparatively short time after hatching, how- ever, it has usually buried itself out of sight. Thus a larva hatching at 9.50 a.m. on wild plum remained in the egg cavity until 10.45 a. m., but had disappeared in the flesh by 11 a.m. A larva hatching at 10.46 a. m. was found partly entered at 11.07 a. m. Three larvee found in their egg cavities at 9.40 a. m. entered the tissues at 10.20, 10.26, and 10.40 a. m., respectively. A larva hatching on apple at 9.30 a. m. did not succeed in getting out of sight in the flesh until 1 p. m., though upon hatching it at once began to burrow. Frequent dissections from fruit of larve of known age indicate that within 2 or 3 hours after hatching the fruit has been penetrated. The course which the larve may take in the fruit is somewhat variable, though in general the pit or core is soon reached. Some detailed observations were made on this point by Messrs. Girault and Rosenfeld (Table XIX). TaBLE XIX.—Course in fruit taken by newly-hatched plum-curculio larve. Dates of x Nes Fruits observa- Kind of fruit. oa exam- Course taken by larvee in fruit. tion. PE arg ined. Apres) 20 ee Reaches... ees Base. qsenseece 1 | Straight into pit. May; ese: Red June plum...---- APO ecec scene 5 | In almost to kernel, then around to basal end of pit. aw ie Oeste ones cee Das alebee ence 2 | Into side of pit, then around to apical end. Pas 3 dos. 258 Se cee ses] BaSO sees ee alee Do. Se CO Ko eee ee ere Se No) oyre eG ee 1 | Straight into pit. fee Coz. - 24. ee) Basalt ees. 2 | Straight in about 7; inch, then around to apical 4 of pit. Dee ss Se Gos essere eee Apex 1 | Straight into pit. ae § 0520.4 S25 os | HB asa soos - 1 Do. Elberta peach.......-- Center side... - 1 Do. aoe (6 (eee eee maa] ae) sos a0 (iss 1 Dos « 3 13 ft eae dovs225. 3232 ieee doz 1 Do. Rear (6 Co ey een! (ial bys \cfaja Se 1 Do. eae Witldiplumie.snce ae en Apex.... 1} Around under skin for a short distance, then in toward pit; then out toward side of fruit, and in an irregular manner down to about center of side and finally to pit; LIFE HISTORY AND HABITS: THE LARVA. 55 Taste XIX.—Course in fruit taken by newly-hatched plum-curculio larve—Contd. Dates of Bs Fruits observa- Kind of fruit. Leeann of exam- Course taken by larve in fruit. tion. PuEGhes: ~ | ined: May 16...-.- Red June plum....... BaS@ucineinco a 1 | In to base of pit. Veen Early Belle peach..... Center side.... 1 | In to pit. One Wild plumc..<.4....4 Basal! $c. sceee 1 | Under skin about + inch, and around to center of side, then into pit. Apical 4......- 1 | Into pit. Basalisos so -5. 1 | Straight in and into pit. Apicalide eo 1 | Straight into pit. ee oneeccelesincnleee es Ogee eee 1 | In straight to apex of pit, and then around to center of other side of fruit. eeeUOecccseseecscscas: Apical's. <<... =. 1 we ppical 4 of pit, then along pit to center of side. Seen Pte AO sansa cu cieccaseias IBaSOee es ceceet 1 | Intopit; around to center side and into pit. Gs GOees a eect bese Center side... . 1 | Into about center of fruit, then to basal 4, and down toward pit. Sseec| Kees Owiscs-osseeess5-]=i55- GOe- nstece 1 | Straight into pit, then along pit to apical 4; then down side of pit. Prof. Crandall has recorded observations on the course taken by larve hatching in apples, as follows: The course taken by the larve on emerging from the egg has been traced in a number of apples, and is found to be variable. In one apple examined the bore proceeded straight from an egg cavity near the basin to a point just beneath the skin on the border of the cavity. Another bore was traced in a spiral 24 times around the fruit. Other bores were found to be tortuous, but in no apple examined did the early bore extend to the core. LARVAL INSTARS. The number of molts made by the curculio larva in the course of its growth has not heretofore been determined, probably on account of the difficulty of following the growth of the insect in the fruit. Mr. Hammar, during 1910, in Michigan, determined the number of molts and length of the respective instars for 10 individuals, as shown in the following table: TaRLeE XX.—Larval instars of the plum curculio. Dates of molting. Individual No. 7 2 : ee S irst econ ir t Hatched. molt. molt. molt. fruit. Adult. June 28} June 30] July 2)| July 5j| July 9/| Aug. 4 June 30} July 2)| July 4] July 6 dose Aug. 10 =e Eee 002-82 | ido ee Edo aly 7) |e aoe = || Aug. 14 Jaly “| ulys 3h Tulys 7) | duly LO oly? 1b |S2ce2so-- ot See do... -do.....| July 6{|July 9{| July 14] Aug. 16 July 2°) July 4 '|<..do...-- July 8] July 11] Aug. 12 -.-| ae do.....|.-.d0,--..) July 7} July 9°| July 12 | Aug.15 July 4] July 6] July 8] July 11] July 16] Aug. 29 July 5] July 7] July 9/] July 12) July 18] Aug. 15 56 THE PLUM CURCULIO. TaBLeE XX.—Larvel instars of the plum curculio—Continued. Duration of larva Jinstars. Individual No. Third Fourth instar in fruit. First Second E : Total days instar. instar. instar. to adult. Days. Days. Days. Days. ou WNNNNNNYNND www noch oo CH OO CO CT OTN CO r“ oO 27 41 393 2.7 4.1 39.3 He NNN wWNwkb bh =| S = & na ; ; i to os i) was) Measurements were made of the width of head-casts of the respective larval molts in the case of one larva, as follows: 0.306 mm., 0.425 mm., 0.595 mm., 1.02 mm. Head measurements of 19 larve at time of leaving the fruit showed a range in width of from 0.935 to 1.071 mm., the average of all being 0.998 mm. DEATH OF LARVZ IN FRUIT. There is much evidence to show that many larve die within the fruit, though the cause, or causes, of this mortality is not easy of positive determination. In general, if the fruit falls at the time or shortly after the egg is deposited, this insures favorable conditions for growth of the larve. If, however, the fruit remains on the tree, the chances are much more against their successful development, and in the case of some fruits, as the apple and pear, almost entirely so. Prof. Crandall has made interesting observations on the mortal- ity among larve in apples. In a lot of 716 fallen apples, 169 curculio larvee were found, 103 of which, or about 61 per cent, were dead, from causes not established. Most of the larvee found dead were less than half grown, and many were not more than 2 or 3 days from the egg. Although it is not so stated, it is probably true that these larvae were killed while the fruit was yet on the trees. The mortality of larve in fruit for the most part results appa- rently from the crushing effect due to the rapid growth of surround- ing tissues; and in the case of stone fruits, as peach and plum, the abundant secretion of gum is perhaps an additional factor. The extent of mortality also varies with the different kinds of fruit. Thus in the case of apple many observations show that larvee are almost never able to survive if the fruit remains hanging on the trees for some time after the hatching of the eggs. The eggs for the most part hatch, and the young larve begin to feed inward, but before they penetrate far they succumb. Such larve show evidence of having been crushed, and often the burrow behind them is well grown over. Apples punctured while still small are most likely to fall; and LIFE HISTORY AND HABITS: THE LARVA. 57 after the apple has grown to three-fourths inch or 1 inch in diam- eter the punctures have much less effect, though the fruit may fall during the thinning process of the tree itself. The egg and feeding punctures, however, usually result in disfigurement of the fruit, often very extensive, as will be discussed under another heading. During the 4 or 5 years that the curculio has been under investi- gation no observations have been made wherein the larvee have sur- vived to maturity in healthy apples on the trees, with the one excep- tion, as observed by Mr. Johnson at North East, Pa., on July 16, 1906, of the occurrence, in a ripening apple on the tree of the Yellow Transparent variety, of three nearly full-grown larve. (See Pl. IX, fig. 10.) As in this instance, it is possible that when eggs are depos- ited in summer varieties as they are beginning to ripen, the resulting larvee would mostly be able to survive, since the stage of rapid growth of the fruit has passed. On another occasion in this locality Mr. Johnson observed, August 1, 1906, in an orchard of the Baldwin variety, numerous small and highly colored apples on the trees about the size of walnuts, some of which contained full-grown curculio larve, and other fruits showed their exit holes. Unquestionably in this instance the normal development of the fruit had been checked from other causes, though it had failed to fall. The condition is not essentially different from that when the fruit drops to the ground. In interesting contrast to the practically complete death of all larve hatching in apples which remain on the trees, and to a large extent of those which do not drop until some days after hatching, is the condition found to obtain when eggs are deposited in confine- ment in apples removed from the trees. In such cases, as has been observed frequently, a large percentage of the deposited eggs pro- duces mature vigorous larve. Figures obtained by Crandall, involv- ing 1,474 eggs deposited in fallen fruit, show that 1,238, or 83.92 per cent, of these resulted in mature larve. In the case of pears, although these are oviposited in freely by the beetles, larvee appear never able to survive in fruit on the trees, and but rarely on fruit on the ground. Unlike the apple, the young pear, when it falls, tends to dry up, and on account of the stony tissue present becomes very hard. In 50 young fruits of the LeConte and Kieffer pear taken from trees at Myrtle, Ga., May 2, and bearing numerous egg-punctures, no live larve were found, none of the punc- tures was fresh, and all were more or less outgrown. An examina- tion of the egg cavity showed in most cases, however, borings of the young larve, and their dead bodies. In lots of Kieffer pears containing eggs, collected at Myrtle, Ga., April 9 and 20, the eggs were observed to hatch, but larve failed to develop. Pears of this same variety collected from the ground April 13 and 20 and May 9 gave no results except from one lot, 4 adults 58 THE PLUM CURCULIO. being reared. Further attempts at rearing from pears in this locality gave no results. May 21 and 23, 1905, at Washington, D. C., and again May 30, 1905, young Kieffer pears from trees were confined with beetles, and eggs were deposited freely. No larvee, however, succeeded in devel- oping. During the course of the season of 1905 many fallen pears were examined by Mr. Johnson at North East, Pa., and he found only a single curculio larva, about one-third grown, feeding in the core of a pear on the ground. No larve were found in fruit on the trees. Observations on plums, wild and cultivated, in many localities show that there is also a high mortality among larve where the fruit remains on the tree or if its dropping be materially retarded. Plums punctured while small are more apt to drop than if the fruit is one- third grown or ever. This dropping of the smaller fruit and the shedding of the fruit by the tree itself enables the species to more than maintain itself. Larvee hatching in fruit which does not fall are ordinarily able to penetrate the flesh but a short distance before succumbing, perhaps due to the combined effect of the copious gum exuded and the pressure of the growing tissues. The evidence also is that the egg may be destroyed by the gum exuding at the punc- tured point, and our notes show the examination of many punctures in which the egg could not be found, or was crushed, the cavity being completely filled with gum. The number of eggs or larve missing has been quite too large to be accounted for otherwise. Many plums of the Japanese and Domestica types and of wild native sorts have been examined when taken from the trees and bearing egg punc- tures, and the conclusion is evident that larve are not able to survive during the rapid growing period, and, as in the case of the apple, their successful development depends on the falling of the fruit. After the fruit has become grown, and the ripening process begins, larve are more likely to survive, and ripe wormy plums, especially of the cultivated Japanese sorts, are not infrequently to be met with. The development of the peach, with reference to its availability as a host for the curculio, may be divided into three stages. The first stage includes the time from the beginning of oviposition to near the time when the pits begin to harden, a period of 3 or 4 weeks, during which approximately 75 per cent of the total infestation of the season occurs. The fruit in this stage, though growing rapidly, does not exude gum upon being punctured and readily drops from the tree when infested by curculio larve. (See Pl. V, fig. 1.) Prob- ably no fruit infested at this time remains long on the tree. The second stage in the growth of the peach begins when the pits show the first signs of hardening and extends up to the ripening period. LIFE HISTORY AND HABITS: THE LARVA. 59 At the beginning of this second stage there is a sudden cessation of both egg laying and feeding, and during the whole time the beetles refrain from puncturing the fruit except in occasional instances. The fruit in this stage exudes gum very copiously when punctured. (See Pl. VI, fig. 2.) Relatively little growth is made while the pit is hardening, but in the few cases in which eggs are laid and hatched at this time the larve are killed at an early stage by the flooding of their burrows with gum, the fruit failing to fall from the tree. The third stage includes the ripening period, when the beetles resume oviposition and the larve are able to mature normally. It is at this time that all the infestation of ripe fruit occurs, though the number of individuals developing is small in comparison with those in the young fruit which falls off. Another factor in the mortality of larve in drop fruit, as noted by Crandall in apples, is the effect of sunshine. According to this gentleman, no living larve could be found in fruit exposed to the sun for a few hours, whereas fruit taken from under the shade of the trees contained a fair proportion of living larve. An interesting experiment is quoted, bearing on the matter: In one box were placed 200 apples and in another 250, the latter being placed in full exposure to the sun, Later examination of soil in the respective boxes gave for the former 42 pupe and for the latter 3 only. As suggested by Prof. Crandall, this points to the advisability of following a method of orchard management which will insure as free access of the sun as possible. DESERTION OF FRUIT BY UNDERSIZED LARVA. On many occasions it has been noted that larve may leave the fruit before reaching maturity and burrow below the soil as for pupation. This premature abandonment of fruit is perhaps often forced by reason of the unfavorable condition of the latter, but in many cases this explanation will not suffice. Fruit in an excellent condition for feeding purposes has been often thus deserted. An unhealthy condition of the larva itself, as from parasitism, might be suspected, but rearings of such individuals indicate that this is not the case. Larve have at times been observed to leave fruit, as in a glass jar without soil, and, in the absence of suitable surroundings for pupation, reenter the fruit and there finally pupate. It is doubtful, however, if there is any tendency of larve to leave one fruit in search of another, and a faulty instinct seems most likely to account for this behavior. Larve emerging from peaches and plums collected throughout the season (p. 62) at Washington, D. C., in 1908, varied in about the following proportion: Large, 45.25 per cent; medium, 60 THE PLUM CURCULIO. 39.04 per cent; and small, 15.69 per cent. Adults were never reared from the small larve, though the attempt was repeatedly made. At Barnesville, Ga., during 1910, observations were also made on this point. Among the first larve of the season to leave drop fruit was a large number of undersized individuals. Many were not more than one-half normal length, and from this they varied to full size. The proportion of small larve was greatest during the first week or ten days after larve began leaving the fruit, the proportion becoming less and less until by two weeks after the first larvee began emerging practically all individuals were of normal size. In Table XXI is shown the proportion of undersized larve during the period from May 2 to 21, when they were in evidence. TaBLE XXI.—Record of undersized and normal larvxe of the plum curculio from drop Jruit from 81 peach trees, Barnesville, Ga., 1910. | | Larve Distinctly | Larve Distinctly Dates. leaving undersized Dates. leaving undersized fruit. larve. fruit. larve. Number. | Per cent. Number. | Per cent. Mawadeon Se set sean 49 38 085 \ Mayet 2 eS tee Ae sea 272 8 Seoue ese aes 68 33 48 1S scene nae 159 6 4 ih ek eemst 119 48 40 Ne. Se ese Carita 86 5 6 ih See oe ae os ee 164 66 40 1 eae eee 58 2 3 Gees - eee ols 175 26 15 AGT oer See ee 48 . 1 2 DR a5. se 99 26 26 ly Re aero Sey 38 1 3 hE aera ae 110 12 11 ASis 34 ees es 33 OV ee se aoe eee Mee ates oe 357 80 22 9) oe Sarees 71 1h eee Oc Set oe Sees. 240 29 12 De Riss eee 102 1 1 dp Peers A epee ae arr 209 28 23: | De esciisseee 54 1 2 II NORMAL EMERGENCE OF LARVA FROM FRUIT DURING THE SEASON. In order to determine over what period and in what abundance larve left the fruit and entered the soil for pupation, as bearing on the period for cultivation for the destruction of the pupe, it was planned in 1908 regularly to collect, at frequent intervals through- out the season, all of that fruit which fell to the ground and to rear and record the larve as they emerged from the respective lots of fruit. This work was done during 1908 at Siloam Springs, Ark., using all drop fruit for the season from 120 peach trees; and during the same year at Washington, D. C., by Mr. P. R. Jones, with both peaches and Japan plums, using all of the drop fruit on 10 peach trees, and in addition to the drop fruit from 8 Japan plum trees that from the trees at ripening time was also. used. During 1910 similar data were obtained at Barnesville, Ga., and by Mr. Hammar at Douglas, Mich. In Georgia all of the drop fruit throughout the season from 31 peach trees was regularly collected and larve recorded as they came from the respective lots. At picking time the fruit from 12 of the 31 trees was gathered and LIFE HISTORY AND HABITS: THE LARVA. 61 larve recorded, but for uniformity the estimated number of larve from the fruit from the 31 trees is used in the table. In Michigan the drop and picked fruit from 15 peach trees was used, collections beginning June 30 and continuing to August 27. These records, it is believed, should show the normal seasonal history of the insects in this stage under orchard conditions. Such eal ; FS ie \ IN Sc Sy P45 He [ Needaaclas dela \y < X N $ & & S S Fic. 20.—Diagram showing normal emergence from fruit of larve of plum curculio during season at Siloam Springs, Ark., Barnesville, Ga., Washington, D. C.,and Douglas, Mich. (Original.) records are evidently much more reliable than those which do not take account of all of the fruit for the season. In Tabie XXII are shown the totals emerging for each of the four localities by days, as also the number and percentages of larvee emerging by months. These same data, summarized by weeks, are shown graphically in figure 20. 62 THE PLUM CURCULIO. TaBLeE XXII.—Emergence of plum curculio larvx throughout the season, from total fruit, in various localities, 1908-1910. Barnesville, Ga., Siloam Springs, | Washington, D.C.,| Douglas, Mich., 8. 1910. 1910. Ark., 1908. oo 4 oD : tn ‘ on 4 Me a ee amare cate Ere as jos. | = me | 8 | 8. | Rh LB ee |e ee as ee Bee oO g {)) g o g (3) g Dates. Bu seen lf isles a. | se eLIE u oF fra | Oe eg 2 ee ies ee ee BS) 8 | 98 | PS) 8 [es |e) Ss \ee)| pe aniiae Fe| « | se |/Se] . | #2] Gb] » | SE] EE] 5 | Se Says Pe se Ss pee eer Re ets see 2. | 8°) 82 (2 a era Sy es a Se eee fo) ° i) fo} fo} >) ic) ° @O ° jo) i.) & ela |e ae ia |e ela fe B 1a Dune ay se eee cee sace LIFE HISTORY AND HABITS: THE LARVA. 63 Taste XXII.—Emergence of plum curculio larvx throughout the season, from total fruit, in various localities, 1908-1910—Continued. a Barnesville, Ga., Siloam Springs, |Washington, D. C.,| Douglas, Mich., 1910. 1908. 1910. Ark., 1908. Bo 5 |e 80 9 ued bo ; | 4 ew | 6 (ld g s|3s |g a | es | 4 a Se we [ed Ca 0 q oO i-T0) =| o 0 q o aye) | oO 5 5 5 rs) 5 3 5 ° Dates. Ee ets ee Mie ariel emia tliceig UAE ea Besa Tene em] 4a “ad | om] “ad | om] wa | Om] € |g a 8 ~ Cs) S = 8 g S CI oS 1 Bo) 3 | es |pe| S| a8 | bt! $ | 28 | Fz) 8 | Be Bele | Sh /55| & | 88 (85/5 | fF | EE) 5 | Se _ Ln) = _ | —~! — BE ey il ere Sse) tee WerSolteryolaiel ae Pe 3 } 5 3 ° © } =) S Sees o a & uy & a ay a a Ay ES en es July Aug. 74 : | 2 tts) | ee ee 3,264 3,264 |100.00 |5, 920 5,920 100. 00 |6,588 |6,588 |100.00 | 895 | 895 pone In the above table, the Georgia records show a total of 3,264 larve leaving the fruit between May 2 and August 9. A large majority of these, 2,665, or 81.64 per cent, issued during May; during June only 42, or 1.28 per cent, issued, while during July, 458, or 14.02 per cent, was secured. August shows a total of 99 larve, or 3.06 per cent. At Siloam Springs, Ark., in 1908 a total of 5,920 larvee issued, the interval covering the period from May 12 to August 13. Larve to the number of 3,664, or 61.89, left the fruit during the period from May 12 to 31; while for June, 1,715, or 28.97 per cent, left the fruit, a total for the approximately 7 weeks of 5,379, or 90.86 per cent. 64 THE PLUM CURCULIO. July shows an emergence of 467 larve (7.89 per cent) and August 1 to 4, after which no more emerged, 74, or 1.25 per cent. At Washington, D. C., during 1908, a total of 6,588 larve was reared, 1,115 emerging during the last 7 days of May. During June 5,002 larvee left the fruit, a total for May and June of 6,117, or 92.85 per cent. Only 7.12 per cent of the totallarve emerged during July, emergence practically ceasing with that month. The Michigan rec- ords include only 895 larve, of which 889, or 99.33 per cent, left the fruit during July. The foregoing data, with the additional records by Crandall from Illinois, are shown in Table XXIII with the dates of blooming of peach trees for that year. The relation of these data to the time of making cultivations is shown on page 176. TaBLe XXIII.—Emergence by months of plum-curculio larve in different localities. | May. June. | July. August. | September. Approx- ; ; : ; - imate eh al 2 Ee 2 date of | “% Sh Eb Sp aT Localities. full le: ; 5 ‘ : ; g 3 3 som 0 g | g g peach | 2 | ao) © fa se ig 1.4 a ae trees. g a g a Q = R a R a Be Boe ec) BB hoe i Be a Se eee ee a 3) a a a ® a ® a ® ° 4 AY 4 = 4 Ay 4 Ay =) _ & Barnesville, Ga.......- Mar. 15 | 2,665] 81.64 42) 1.28} 458) 14.02 99] 3..06).-=..- yee 3, 264 Siloam Springs, Ark....| Mar. 18 | 3,664) 61.89) 1,715) 28.97 467| 7.89 TAY E25) Seas be ee 5, 920 Washington, D.C...._. Apr. 6] 1,115} 16.92) 5,002] 75.93} 469) 7.12 Z|. ° O03) 22 ess |seeees 6, 588 Douglas, Mich.......... 05 poe" 0)p| eee se | Late See ES Shs Ree 889] 99. 33 eC sees eaec = Gricesville ieee e228 May OL |stats eee 254] 20.52) 662) 53.47] 272) 21.97 50} 4.04) 1,238 1 Apple MANNER OF LEAVING THE FRUIT AND ENTERING THE SOIL. Upon completing its growth, the larva leaves the fruit in which it has been feeding, and soon makes its way beneath the soil. Fruit lying upon the ground will usually show, when examined, the small exit hole of the grub, mostly along the lower side where the fruit was in contact with the earth. An examination of 200 infested drop peaches showed these exit holes to be located as follows: Apex, 8; apical third, 64; center of side, 66; basal third, 46; base, 16. This shows that 88 per cent of the exit holes are along sides as against the ends, which is perhaps proportionate to the respective areas. In deserting the fruit on the trees, as peaches and cherries, the larva must fall, and this is probably not injurious to it. Once upon the ground, the instinct is immediately to get below the soil. The time occupied in accomplishing this will vary according to character of soil, whether cultivated or not, and the presence of crevices, etc. At this time especially the larve are exposed to predaceous insects, par- LIFE HISTORY AND HABITS: THE LARVA. 65 ticularly ants, and numerous larve perish from their attack. Many larvee have been timed by the watch, and the interval occupied until out of sight below the soil has varied from about one-half to 50 minutes, Table XXIV includes observations made inGeorgia and in Washing- ton, D. C., both in the orchard and in small jars in the laboratory. It will be noted that more time is usually spent in searching for a suitable place to enter than in actually working below the surface. The average time on the ground and until beneath the soil, in the data given, is about 12 minutes. A larger series of observations would probably change these figures somewhat. Taste XXITV.—Time oceupied by larve of the plum curculio in entering soil. es -_, | Began| Be- Time Localities. ran : pe toen- | neath | occu- | Kind of soil. N08 Sat Peter: soil. | pied. | Myrtle, Ga.: ‘itivitetess| Hhuaboratory=.:.-.<--- 1} 10.00 | 10.06 | 10.113 11} | Fresh sandy loam soi! in glass jar, | gently packed. P| PRU 2.15 2. 21 14 Do. 3 | 10.21 | 10.21% | 10.22 1 Do. 4 9. 13 9.14 9.15 2 Do. 5 | 4.08 | 4104 | 4.12 4 Do. 6} 9.59 | 10.00 | 10.03 4 Do. 7 | 9:43 9. 44 9. 49 6 Do. 8 | 10.22 10. 28 10. 24 2 Do. 9 | 10. 22 10. 25 10. 30 8 Do. 10 4.16 4.18 4. 26 10 Do. imierchardss-- 5<-- =. UN gag De | eee 5. 23 1 | Dry sandy soil under peach tree. 12 15 ya | 5. 26 4 | Do. 1Dis|e Oneen Ebest, §.27 5 Do. TAS O22 BY j= 5.31 9 Do. Laue al aacete ee 5.34 12 Do. UG lero 22 eee a 5. 39 17 Do Ly (lk S77? ek ae 4. 49 i al Do Washington, D. C.: : inseetaryss:-.-:-2--: 18 | 1.263 1.29 1.41 144 | Sandy garden soil in box, moder- ately compacted. 19 1.30 1. 59 2.19 49 Do. 20 1.48 2. 40 3, 23 35 Do. 21 2. 23 2.36 2. 40 17 Do. 22) 2.10 2. 37 2. 42 32 Do 23 | 2.44 2. 46 2. 47 3 Do 24} 2.23 2. 41 2. 44 21 Do. (inorehard..-.... 2-5-5 D5 W255 250 By all 16 | Clay loam, well cultivated. Larvee placed under plum tree. 26] 2.55 2. 56 3.00 5 Do. 27 | 3.33 3n34 | 3236 3 Do. 28 | 3.03 3. 15 3.18 15 Do. 29 | 3.20 3. 22 3. 25 5 Do. 30 | 3.144 | 3.154 | 3.164 2 Do. TIME SPENT IN THE FRUIT (EGG AND LARVAL STAGES COMBINED). In 1904 Prof. Crandall determined, for Illinois, the time spent in apples (combined egg and larval stages) for 1,238 individuals. A few larvee left the fruit within 12 and 13 days from deposition of egg, and some spent an unusually long time in the fruit. The great majority, however, developed and left the fruit in about the average time. Table XXV gives his emergence records by months, and also the average period per individual within fruit for that month, 17262°—Bull. 103—12 5 66 THE PLUM CURCULIO. TasBLeE XXV.—Length of time spent in fruit by plum curculio, Illinois, 1904. Total num- Average ber of Percentage = A Months. larvee of whole. yer, emerging. e Daus MUNG eee oe owe 5 See ae es pa 2 Ss ome ace eee eee ee 254 20. 52 18. 07 Ut Seas abo aeeSoopeen se oeeer soaaceneeseecomor See Cadet csetnccnste 662 53. 47 19.15 INGOTS ieee oee seen ness saab aes cdo eowouecadbas ecansoscseeacascss 272 21.97 21.55 Swot) oN BBS ceencn acho s secon ane opoarsSs Somseescoascosescgec $55: 50 4. 04 26. 00 Motel: ce. cats dcx See a Sosa eee ee ee ee eee 1, 238 100.00 | The average time for egg and larva in the fruit for the whole season was about 20 days. In Table XXVI are given records of a few observations from Youngstown, N. Y. (1905), and North East, Pa. (1906). TaBLE XXVI.—Length of time spent in fruit by the plum curculio (egg and larval stages combined), Youngstown, N. Y., 1905, and North East, Pa., 1906. Larve emerged Ap- |Total| Total Aver- proxi- | num-} num- mate | ber of| ber of time |larvee | eggand in |devel-) larval fruit. | oped.| days. Eggs Localities. depos- | Date of depo- ited. sition. Num- Dat ber. ale: Daus. July 10,1905 | 16.00 July 12,1905 Hl 17 | 303.25 | 17.83 Younestown;iNav.ss-s5-=-22= 43 | June 24,1905 | July 13,1905 | 19.00 July 3.1906 aan 7 | 169.50 | 24. 21 July 51906 | 20.75} 6 | 124.50 | 20.75 July 3.1996 | 18.00] 4] 72.00 | 18.00 June 14,1906 June 15,1906 He Db Oro Co eH OO oy S ae “<{ © = ie) =) ( 1200 \ 7! 93.00) 13.29 | Plum Total and average......... Ss eSo0000 163 | 2,549.25 | 15. 64 4] June 26| 19.25 | 15} June 6-7 8 | June 27 20. 25 | 15 308. 75 20.58 | Apple i 3 | June 30 23.25 | June 9-10 4/ June 24 14. 25 4 57.00 14.25 | Plum. 7 | June 10 2) June 21 10. 50 2 21.00 10.50} Do. 1} June 25 12. 25 ? 24 | June 11-13 Tae aie a ee a 21| 374.25| 17.82] Apple ajay) Bled bye aL 18.75 9 | June 27 15.00 | = 13 | June 10-13 { Pe aeneodt le sires er \ 11| 166.00] 15.09! Do 10 | June 29 4.75 | 20| June 14 { aie oy Ne caetce } ig| 273.50] 15.19| Do 10 | June 14-45 { peo iea ln Goce \ 9] 129.00] 1433] Do 2 | June 17 | 2! July 4 | 17.00 2 34. 00 17.00 Do Motal-andayerage.<25-< 2. ceese set 82 | 1,363.50 16. 62 PotalionSeasou jase. ass dcscsce acess eee BAR eo Otonto. panacea AM ETarp ime spel plnicUib tor SCQS0M, GAYS. jews .c= sec ace soem san acre enwice ce maicanten aeiecee =n seen 15.99 The records show a range for combined egg and larval stages of from 104 to 234 days, with the average for the season of 15.99 days. The total number of larve under observation was 245 and the sum of egg and larval days was 3,912.75. Observations made at Myrtle, Ga., during 1906, on miscellaneous lots of eggs and larve in peaches, during April, May, and June, are detailed in Table XXVIII. 68 THE PLUM CURCULIO. Taste XXVIII.—Length of time spent in fruit by the plum curculio (egg and larval stages combined), Myrtle, Ga., 1906. Larve leaving fruit in specified days from deposition of eggs. Total Eggs 2 Mature bs egg de- | Date of | jarvee | | and pos- egg depo- devel- | | | larval ited. | M400. | oped. | 11/12]13/ 14| 15| 16/17] 18 19] 20| 21 | 22| 23 | 24) 25 | 26 | 27 | 28 | 29 | 30 daysin ruit | | I |: Ale he es 9} Apr. 19 4 3 1 ie : Ba) Besos ea Bee eealaac Aad inctccend 21 | Apr. 21 A See Ves |e ee Ke) ee all ae: | S| ee cee ea 7 (tee | eas eee (?) | Apr. 23 3 Lipa | === 2 |. ABS al aissleoctee, 4 Bae lane | paneeene (?) | Apr. 26 Fi | 3 lt al eet ae [Pattee | el ra Se Ao 8 |e eee (2) | Apr. 27 D) |eec|Sealeealeee --- | 3 -| 1 3 aes See hiss) Rael lsec Wee leecesase Total. 23 3|4]...[2]4]4|3]1 Tel eae le al i ae 395 15| May 1 ie (es a ie ae ies a Pe pe eae 14| May 7 eS) | Peel es ee | pee fh | ee he al corel selbst oe eee | ee 7| May 8 Muteee| sae caine iO eels |e ea a sd onal aniees lee eee | a 12| May 9 (fl See BSA Speloos ecaeall ein oct ease) 2 ee cael (slr a Bee Bee Bee ae eat coe ated 13 | May 10 Sees ale Se Sa Lien eee Te ee a 1 a a ee roses 6| May 11 yi ae le Mal al =| ete Ul ere | ee WEA pclae eee 2 a|eel bee ae eee 7| May 13 rn See ee Grip aes el see a eee ee Seeleosl eee Behe pewcerioe 14 | May 14 7 | Has a Sees eae en i ae peel ees) aml ot ee eases f 16 | May 15 On [Pears See eee Sil, Sales] S| cal ce ol ieee ie ao | eal ey eee 16 | May 16 10 |. a “Vee ANG se | all | ie i |e | x rae ft ete 14 | May 17 9/1 | nT al etic | es ee 5S eee ees int 12 | May 18 (alse eel See ects 1 (el 2s eS sel ee Bes ee ee cede (Singesaoac 11 | May 19 (itl Se) a See ee ote ieee. PA eel Bese be wel: WU ee Sl = ls Si | ere | ae eee 20| May 20 (Sil Patel eal eal fae Pees pe pee UPS) |) i pee Par (2a [OE 11 | May 21 (ile ea Balle Hy eB fae a i 1 Sales ea {| ewe 8 | May 22 3 |. soallsde ae Hs a DTT an) all Se Sa leseleeeleee Fe PRs ee) ei ee 5 | May 23 Pate | Aen ee egal eee 1 ee ae a ee ae Pope) Wr Hal ee ee ee Sl a 4| May 24 2: A tS else eel ls 3 LE Elo ul 7 | May 25 a (ea Se aoe 1 = 5 | May 26 7) loo 5laSo)/238| 350 if . Total.| 16/1 |5|8|9 10| June 2 a ae eal cg erie G 6| June 8 Ohi sara see 1/2 eee 13 | June 17 Dios s|seeleaapaen|) Aae Total. ity el eee else Total for liga ty April, May, | and June. .| 155) | Lo.) BS LS, HS) 2ON | 200 Si Ge SS Se eae ken alte Average’ time indnuit for Aprils) 2222.5 sce coe sess aoe oeee sale oe hoe ees days.. 17.17 ‘Anverage: time im fruitdor May2 oy 2. Sco sScnc yas ieee ac ees eee cincise ts nCen coment ee anaes do..-. 18:21 Average timeiniiruit for June. 2 =. eS. se ance encieen ce cee eee caren eae eas occ aceon dou. 5 dose Acyeraceitime initruit forsAiprill, May), and! June s-ee see eaen es seein cee eee neta Gone saline A total of 155 larve emerged, the time spent in the fruit varying from 11 to 30 days, with an average for the period of 17.81 days. Table XXIX gives observations on 411 larve reaching maturity during May, June, and July, at Siloam Springs, Ark., in 1908. The fruit used was peach. LIFE HISTORY AND HABITS: THE LARVA. 69 Taste XXIX.—Length of time spent in fruit by the plum cureulio (egg and larval stages combined), Siloam Springs, Ark., 1908. Larve leaving fruit in specified days from deposition | Tota] : Eggs| Date of Mature of eggs. egg . de- eretdente larvee |_ oe and ; pos- = Tne 4 devel- larval | ; ited. oped. | 15] 16] 17| 18] 19) 20) 21 | 22] 23 | 24] 25 | 26] 27| 28] 29] 30 daysin 8| May 12 Chol [etal eal E-press fe ak PPT es lM a eS a || ele en 6| May 18 (3a) [ERs esis el eed eee a Eee a Ta Trt Mg UH a 10| May 14 5] Keane (Ee Sa fa | | he Vine Tse [| ea 38 | May 15 EY ey ees tee (eed eee ep et UD ath re et 1 eet es a peg 56 | May 16 UP Ja ee Bee ee eee 4 31 DD Aisle eral eel Mel geal caret areca leas Sele e et ae.cs 39 | May 17 37 =| eR eed ese LO A 0 a Mat | | be eel be Se be el |e ee ge 30; May 18 eT RSE ee elise ea SE aoe eet EG etd Wes) (fet a ee Seer 10| May 19 (7s| [Be (el (ye geet SR yell EN 8| May 20 Sym ee en aly | ere se ve ae eelleseraatece 16| May 21 HU hal esyal pall 2 | Pee eee eee 10| May 22 (ee hee nee eee Sl cles oacene 16 | May 23 DSF fe Feed eae UU Mn pa Ay | oS Bane 16| May 24 Gy ee. | eee eels 3] re SETS Te tea WS elt eae DR eee 7| May 25 Gy |e FH eae hen Toa ee S| ata ed kel J | a ee 9| May 28 i Eeligee GF | Peg Bem] TTP Fel Dg | ee ee 8 9| May 29 8} eae E z ee eats aeee| ecm ed ale culcpee aes 7 | May 30 Ullal Bea Bs (a 3 Ra Pe a | eee cepa 8| May 831 7 EAE eee eae ee y Sax 1" es) Wee (I IPE a ee Total 260 | 1 | 7 /13 | 3 |24 |81 [52 |27 [21 |l1 112) 4/3)1 5,424 10 | June 2 623 (eal Hee Le a et a a Ai OS eee ere eA St Sea) Real Oe ere 11 | June 3 (6) |e | eel eee | SIP ale aft Pe: Sap Os lO pe) ee = eee 16} June 4 1 eee ees cel fel) aa Pea Es Ves a Re 17 | June 5 1 te eel of es fo | ae fe a PS TESS 9 | June 6 Ol ee ele BFS IE CS ages LG ee Fee 10 | June 7 ee eed f a iSh ea) |) ee 5| June 10 fal | =e eral eel [el (eee 22) le 5 | June 11 ele} nel | (pie UO ae fees see 7| June 14 ie hE (ea eke | i i Va Lb 11} June 15 10 |. 2) at lal SS et eee. 12} June 16 Sap 2 Wer | (eae | ir TRG Tb 8| June 17 to alae mete Ne a see pale d |e 5|June 19 gh AN See ee ES | eel re oe 7| June 20 Gass esl ee hee illo as Pe es 11} June 22 al} ed Selle See est lia ol ta 10] June 25 Gr fee seals 2 ere ee eee 10; June 27 Giiaelees Baal 2\1 Total 137 Pea lSealton | Panlon22n2o 5 | July 7 Steeles |e al Peni ile (bul Ee eee ille e ele a valy, 13 Mie | Seah es i | ES ee a ee |e PR ey | [oe a a fae ee An duly, 15 Bie a) fe Sf hea aS 1S el 0 VL el ee | eee oe 4| July 17 Da eee |e S| FEE Pgs Pa a Fee (eT ||P Eee per 2 suly: 22 LH al Mel ieee be at | ea] tee eo che | eeepc Sa re! Hae eae 2| July 24 a bees eal oe “il el Pe Nl a toe a eR so tS ES Sa 3| July 26 Th | al el Yue ee Ae ‘Ala valeeall | al ee eee Total 14 s|Pee)/bec yO ea Lea My 8 fas A oy |S Fa 328 Total for May, | June, and | Dilys eases 411 | 1 | 7 \13 | 6 |39 |97 |75 |53 |39 \33 |24 |12 | 9/1)1] 14 8,809 | LANGE TORE NNO Negba AO) WE Ga ee Ree Bore eRe ncaesacbone dueoet Sece eee emeor eaecceare se- days.. 20.86 DATS RIRE 2 DPERGY LONE AS (Oi RUE eee SB ne Sane eee nee cone eee eos ean asco do.... 22.31 JAS GUE TER) EAT A Oe eee heen ee Soe ee Ser) saree Soc ROCASe once see oD ESAS pCacesnoaaoe do.... 23.43 Averare timnein innit for May, June, and July <<< oo e See ccna ween mene meaner en eee ee nn Go-22— 21543 e 70 THE PLUM CURCULIO. A total of 411 larvae: was under observation, the time spent in the fruit varying from 15 to 30 days. The average of all individuals was 21.43 days. Observations were also made at Douglas, Mich., during 1910 by Mr. Hammar, on the complete life-cycle period of 121 individuals. For purposes of comparison the egg and larval stages combined are shown in Table XXX. The fruit used was peach. The average time for all individuals for June and July was 20.8 days. TaBLE XXX.—Length of time spent in fruit by the plum curculio (egg and larval stages combined), Douglas, Mich., 1910. | Larve leaving fruit in specified days from deposi- | Total Fggs | Date of tion of eggs. eg and depos- | egg deposi- © larval ited. tion. | 3 | | days in 16) 17 | VS | V9) |.20) | 21) 22°) 23) 24°)525>) 265) 270) fraik. a (ESET (ES eS EY or ae | ete : | | | CO feet oe 2 ene Bertclesea|| dll) ay ale sosl) 1) esac) eeaclesoo|lsene =e 10}; Fane: 299) sSelessal Qo SB GAM A ese a sla = ol ee ee A Waume: sO se Seis] Meee ie aa Se ee | eres egy | epee Petal Bos) aaseoece Mobaleocs- 3 |. cate: vee Lee eee 392 38 | July rit eee Te iteo) eae ce Ble 2 AS eS a S| Ae 20 | July OR ah Seca! Ole Wal Bohesse| weer soe See eeeeeee 19 | July ale LS ACA SS ial ed | eee Pcs. 5 | eons 16 | July 4]. LS2Al Ge NSO Aiea = al eal ee ee Oe ee to 6 | July 6 |. Ga eee ee aes | ahs [Cee Tete Be ee ee oe Hi) alye 20)" S| 5, A es er a es a ere) We eS ee 8 Calya S215\e Sod im ee ee lk ee TA ee rene Motaless. = 1 | MOM ai | Gi les Se ees) il Ly [22) 122 | = 2 Total for | | June and | Tolygeee- AO es22) 1) Sl Taal sS6N Zoe 20s lel eo ateeell 1 | 2,514 - | Average time in fruit for June........-.-......-.-- (Leen LS nd cee a Rie ee a days.. 19.6 ‘Average time sm iniititor UUlyees, ae oe eee nee ee ce ne eee Oe ie ae ee ee dot-ca al Average time iniruit for June and Jilly. aces cee ore Areruse Ales C1 Mel |) [ee ef VR pe |e ee) es ie FE fcc ey selec leclias l-acieeeac Gites 14]. By all Ge Meet heals e el RS ealSa eal eae elea lle ap al Oe eee (nese 11 TN ed a Sea rt PS Sibel alles NF Neos) 3/5) LS elle eR Sc Wen ee- 25 4| 2| 4} 2| 1)--|--| 1]--]--]--]--]--]--}--}--/-|- a ele ee ie eeer 8]. cif vt fell el a Nes fea (SF el lee a Fee) | | pee re then eee ll \ |i Nel oe les eee al | sl eel ee Vere ppc 19 oe 5 eel belles eeeeacase 12. Sass ee Fy) la eal co PRS ST doe | Oy (ae) (Ree el I) es SE epee FAIS A odes cl Vey Peed fell es poed pet ee tanec aS te Be le eel eee ead Selleeled|[ec| eeeeccee Wie Ft el Tae 7 (TP Par Pe ole tS S| ee Sl Bele ee Beaeooe ee ae AFT Were || athlete Eat Sl fce al (ES Ps fea PSS feo be Sa ae ae eee A I Sh Saad | sre AV at Sa SVs a ER SEN Fee Fete | bc a [ae hal ei 26. slat 48}. -| 2| 6| 5] 612} 7) 1] 2) 2)..) 1) 1) 1) 1) 1)-- Se seas SDLe ears ed ret RW a Ved TP PF PR FF af lf sl Ge ee Total 198 131 19}25}16 18)13 5110} 6| 4] 4] 2} 1) 2} 1) 1} 1)- 3, 309 LATE (Bre ae 15 Sa ea ESTES UU S| sale) Melee = (pe) FR Peat Pf be el Fea Baa | 43)_.\_.| a] 3] 3} 6] 2} 3} 1) 2| 5| 6 4) 3} 2) 2)-.|-- S| |b Pe Re ee OP se. Suis SHIR Al GO setesleet Ole Galesli al nal Wie te er ater ol tae oscil el alae ns il eee | Diet mate Ae atte ns ale sey Sal (SA bene SRS Total o1|__|..| 1] 4| 7} 9| 8} 5| 2} s{15| 8} 7) 7] 4] 5) 1 Ree SR ee eer Total for sea- lo | son | Baal aba yie 31 Se lee 15)27}28 12112) 9) 5\11)10 27 ane 9) 4) 7| 2| 2) 4) 2). 1} 10,282 | | Momenpprunein iraiytor Api: 2..<.cs---- Spee Dey ie 177 |. | ps fs as a fe Ue OE hy EEE ee SA EE Re 64 |. 0 ae Die We eS EO Tio RPS 7 Bigs. tae Oy Ce 148 |. a eae (BS ee ee de ee eee ce Py ha tae fioeek ees es 97 |. 25 HERD) | Sal a CAR ORS tte et ae i ne DSr mete he bekeasee ere 6152s eee EM ste a lek] pee yal heeeee|(saes ny pee hk aso DON Ss. Fs A rah SEI DAs Sajpe ee Ds lsu] G Heol ie as ee Oa pee BO acneoe he eae ores Cb Red ete is eS nei rl 5 alk cel ae MO pallens 3 eae ere 4,645 | 1 2| 1 | 2 | 4 /15 [31 63 [80 |38 |83 |72 {81 | 46 165 |36 !29 | 10 Mil yals SE eee hs tae ZY fal eel ces ae eel Pee eee eet mes IPOH CTRL Rall NON oe =|ace es eee OF PANS a tiee eee ro 42 Se ee a Te NR Ge i ae eee . a eek Mee EAE feast oom lees a 34 | Pe Fee fea Pa Ie TE 1 2 a ee Cee Es Gee te ey ee 2d) Ween os ane ee br pa | Yh We ho : Hoe Ce See ere or) (Hees Meee Seal sta ie Piet Je ee Sl Tel ea a Gites Pear ae ie [6 ee |e alee da] ee centr 1 Real Geet en ED) 1 Tie eee ea annk Coane ae ah | eee rel ee AU Vs) Fe a focal ene ACs Ta PR PL lle 1 Pe Sa PERE a Vea pL Veg Pa Dee | pal eee aM fetta beet V1 st rl (eH | 10 Ole Ae as Wee eee 39 -| 2 iN, re ey abe SS. ee = : OS ace ke ey Oe ae 10 raved el ay. SAN Ee (UGB me Ue 9 al esl pee ee a eee 5 Hilt seh ae NA Dees Weed oa 07 141 | |-==|---| Pa [sa e}oma|sea|s a] eel -om) maak fe) een oe er rr ates Ean Gh aac aie cae (es ne (nes a Vee Nee ER Rite ech el | PA SETAE ue 1, eerie he td po od el Bes eel Ress) ese] dod ue whee a] > s5[b0 21 Ee eee Miptalaeece tae Bis ese 326 |...1.2.1 2) 114 | 41 8 74 [3 12 | 71°83) 3S) ee ee Total for season.......- 5,956 | 1 | 0 4|2)|3 | 8 |23 1/45 |76 2 48 98 ‘83 106] 78 |87 \€9 |53 | 34 > | } | . Adults emerging in specified days from time of entering soil by larve. Total Eee Dates larvee entered paales days soil. | | | in soil. aE eRe 37 | 88 | 39 | 40 | 41 | 42 | 43 | 44 | 45| 46 47 |48 | 49 50| 51 | 52153 | 54/56 in soil. | Mag Binaas <2 BF WES ia Gt Foe Wet KT 5 aL 2 85 |acenee DOP cor ne ee DITA | a es 2h ee | ee | baa | Bead ir ei | | 103: ee BUR a ee aN ea Ne ee oy (ES) BE Tapa Pay Pe (ee 39: Seas Site Soe aoe Same Tali |Sae OER) (rest ae Seales | Pa ee = Opals neese 15 26 116 |3/3|/1/3)1/2/1 | 2 09 (tel eae Tuned eee Pons 1 5|2 Beales sae lS 2 Deeb Ue eae DA eee eels Siemens Kee ea ae Soe ae ae ay aed Pel Fs ea Yh I jets PO ee ae eee eer ee 1 Pt Fe Sen (2 23) ST ac ce elie SI Vas Sian Scam: 1 a el Be eee ae [1] 3 1 (aes ees TA Pea ae vf fc | Ps Vi s eee ee SS Lose | es 73a eee (De (oes 3 ees We ae BR ce 1 Ps (en Meg Weed Pots Lie a OE a (2 I Qicce eee seoeiee 2 oo 2 eS eel eee Ot oe els Bed NO ya Me ab lhe ok Ts see eee 1 TS ae (aad Pats ee LOE Ss Se Se te i ae wane aE a [ad 2 Ge aey, Rome GEE Ye Se ist 12 Ta ie : Ve ee ee ay 1 ae eS (2 liane ee 1155 sa ses eee ete a ee 213 We) Bee Be ae a el es ~ Ge eet See eee Sh dalsse eee | meee (ea (EP a (2 (ec ae é UT eee cee ooo s 2108 Da aes eee | f= oS ee oS) | 2 Fi feral ees 3 See sees + ed ee [ees | E 2 ae a ee : Gite ote ened. Fe 1 Nee fe zee ADS 2 See ope RS EE Ee U2 20 Ree R ORO EOF bal 3) Pepe eS) (eee BERS RM fe = ye, | se Pie Pe ES 7) eee eee es eae ee sds dlc sth, otis 1 Lseec Red meuHi cee Ie |e | ae De ee | 2 eH 77 pe ee a ee OF I a fea 2 Pe) PN) ed ES PE LIFE HISTORY AND HABITS: THE PUPA. 79 TaBLE XXXVII.—Length of time spent in the soil by the plum curculio, Washington, D. C., 1908—Continued. Adults emerging in specified days from time of entering soil by | Total | Total Dates laeves entered larvie. - ee days soil. r a ween | SPene 37|38| 39 | 40| 41 | 42| 43 | 44| 45! 46 47| 48 | 49 | 50| 51] 52|53| 54/56) 1 SOll-| in soil. |S Ee ig i a ef (Ws Ps FERS es So Sec Fok a ie on \pateese iS Fed ol ct | ey ey sg et WR) ERG ae TS) OP ee ae OS Nee Total for season |26 |45 |43 26|8|9|8 | |5|5|3/3/2|2]1|4/0|1|2| Average time spent in the soil during May Spee Average time spent in the soil during June 31. 34 Average time spent in the soil during July z - 21.78 VERA DATE SD ON Gill hl© SOL MOL SCASODe sae seeen ne ose oe Se ob ein cieine eae wns owas wees Sere ete) Data obtained by Mr. Hammar at Douglas, Mich., during 1910 are shown in Table XXXVIII. A decided lengthening of the period is evident, the range being from 27 to 58 days, with an average for all individuals of 36.32 days. A total of 177 adults was reared from 207 larvee. TaBLeE XXXVIII.—Length of time spent in the soil by the plum cureulio, Douglas, Mich., 1910. Adults emerging in specified days from time of entering soil by larvee. , Total Date larve en- | 7 aye : Total | days tered soil. : l l ee aT aa jadults. spent 27/28 29'30|31/32'33 34 35/36/37 38/39/40 41 42/43 44 45 47/48/49|50155/58| in soil. Vins je "Cal (ea a jee a a) (a | io ee 6 ee al a al. ie VN oben (eed ged ea Giles eee 7; oe ates ee 1 el a i (A ea et ae 2.24 Se VeNal St AMM 10: | aes peep et iH 2 ES Bs Gr) ee es a a Ge Recess Total... Ay a es a es 22| 849 ae ra Oe 2} 1\12| 2] 3) 2]-.| 5|-.|-2) 7|--| al. Ja) a ih See 2, See 24 --|-[ 1]--|--| 2] 3) 3} 3) 3] 1)..)..) 3).-|..]._. astealin SRO See a ee | 19 HI el blah ed St Ste Bieah dieatoctes } | Rg a ae fe es et rt ed ay a 1a} Soe Cie aan Remon barnegat 4) Dee te bal alee eleale Su) asset eS as 9 A A a a | Ds ey | ae oe (eNOS 42, |_.|..|..| 3| 3] 2} 6/10) 9) 5].-|..|..]..| cM 3a aw 32 t 1 eae a 1 al Fa Ot | : | cn eee Spe See 1D } 1) 1), 2)--}.-]--|-- al --|- |. fi ee aa i 180 | 2| 2 2| 4] 6| 51321 29/1017 15] 1) 8| 4) 6) 7)..| 1 1}1| 155 | 5,585 Total for Pelee Polat eteetalleesl ota ena Psi bade | 9 season... - 207 | 2 9| 4! 4] 6 6 16 22.32 110.19 15 1/10} 4| 7] 9|..| 1] 2] 2} 1)..| 1) 1] 177] 6,434 } Pal } ho oat | Berra time Spent al SLOUNG Urine UUM. << oe ee rien a ne Seen w een ence een days.. 38.59 enrace Line Spey il SrOunG Curing July... 5-226 nema coe aetna win wleidinia oa oso win nese --- G0.<-. 36:03 mverepigine Spent iM pround AiuTINe SEASON <<. 2-2 dames wcin ewe w ere rane owen = n= === ee do.... 36.32 80 THE PLUM CURCULIO. Table XX XIX gives details of time spent in the ground of 1,568 individuals at Barnesville, Ga., covering the period May, June, July, and a part of August. A total of 2,917 larve was used. The range of the different individuals is from 21 days to 62 days—the longest yet noted—the average being 34.44 days. Taste XXXIX.—Length of time spent in the soil by the plum curculio, Barnesville, Ga., 1910. | a el Adults emerging in specified days from time of entering soil by larvee. © re oT) = | ; Date larve en- | 7 vm. tered soil. | | | 21 | 22) 23 | 24] 25 | 26| 27 | 28] 29/30/31 | 32| 33 | 34 | 35 | 36 | 37 | 38 |39/ 40] 41 = | | | { | ae Mayioes Sebastes (He ee ee (eee ried aes ee (ers ee Cd eee tery | Solleest | cb yo 5 Oma ers ABT |o.sbic|Sscles.|edelee eostae ald occlee Sa) atelae) | WSs 16" pie koa teammem met Rh Sedan ae 566 Pay |...|.--| 1] 3] 5 | 10 | 40 | 64| 52 | 37 | 30/10 (ia | 92 ee eae 240 ee Be es eee nna aba mne itil a | a || S he See 209 ae Vesa fea ee ech Bo] 25) 108! 1529.1, 99) 125/800) Pete eee OR Ai eee 272 Bae Des S/S GPa core ate hoi) Shalt ston ese |e Toe ee 159 |}. ey Psat: e2cte sc | 26 19109) 05) [20:22 851 920 e es eee eee 192 |. Sales 12221 6 78 Ss BAD 5 lime PLO oat mate ia 7 eee Te a ee bea 142 |. ob feces} L [02 ) 29 ]).3a/ SOs: (TO! eas (ese 07) asal e eee es Jieetede ae 190) 1) 1)1)-..)2)2])2)1) 705] 9 m1) i) 9) 4) 5 13 | 4 5 DBL EA oe Tae fea eee) Sa ale Pale ESC eC) | er Bef No ai] |S Tl ie s| ih Tees pia te BE a reel ene ee a Merlino bee teh IE eel Sil aba ee aioe a Ea a oe Bie sinceeenee 28 | iT ace a TAN eRe ls Motalee oe 2,631 |1/|1|41|3 | 8 (16 [15 (22 [32 |55 |57 (91 [134 {188 l205 [163 [151 [127 [41 [37 | 21 june bee eee 28 |. al 3 koe eaa 2 ya! i : 102 See a8 14 |_ Ye 5) ee ey |e a é i Motaleis. a 42, | ARAN Sul cAcil el sole Sol aa tat Duly dees ssosSese Ail is ale Ale ele: i ae a Se Qi re) attest Han eae | (ag eal are a 57) ee Pee rae | Sg | : 2 13S Sao Sa eee | Sah eel eee eee PES Nese eee ee ee fee ae aee| Rae okey 36 | pees 2ah easels eeu oueesieee ON ei aaa ae (Qe 7. ees 23 2 BELG TT =| eal ee Lae a ac a as 25 Io De re Da Ue | WGI le PS 1 Fen as Bee 51 Th ecaal eeya potatoe ES SST Te (ses 4 eee ena 27 ig Gee ea ean meio | DON Se eae ee 12 ee cel sewl Seca shale |) Sil BOL eee eee 7g eee [eet Os ae eta Te leet aes BD is ail ae 1 Stee saps ae Bi al ae | 1 th EEN Ta oe 5 clea ets | ae Rotaleseee 210 | 1/3) 8 13 10! 714)5)/713 14) 5 1) 3 Mage tee toe cme 4 LOwleealeen ae 1 ss ial eal oR ss |e 1 Py ie este Ao eee tle al F 1] | ali bselloal[ atl z Tp a ARES 2 a a (eal ot epee ee Eee | Motaleere. BAe eel Me 2a S mal eae Salesa ile 1 1 Brett Total for Pil eee | season....| 2,917 | 1 | 2 |12 |16 |29 Pe Be 42 143 163 pt 96 |139 |189 209 165 |152 |128 |42 |37 | 25 | Adults emerging in specified days from time of entering soil by larve. Total Date larve en- Total | days tered soil. l 42 | 43) 44) 45 46| 47) 48/49 50] 51 | 52/53 | 54 55 56 57 | 58 | 59 | 60| 61 62 LIFE HISTORY AND HABITS: THE PUPA. 81 TaBLE XXXIX.—Length of time spent in the soil by the plum curculio, Barnesville, Ga., 1910—Continued. Adults emerging in specified days from time of entering soil by larve. Total Date larva en-| ba etae ee ll | Total) days tered soil. Vea jure | | E adults.| spent 42 43 44) 45) 46) 47) 48 0 | 51 | 52) 53) 54) 55) 56] 57 | 58 | 59 60 | 61) 62 in soil. biol ss ja 5 | | favgb....<..... jes | tle oe ee ee 2h i ae i eee eon Pee ee | 0 Vi nie Ea ae Calecan Total..... as ro Fe sl rll ee sal SCC old OR 22 572 July 4.......... TE a Nao ila 9 a A Bn Gre (ef es ark oes Nese ee PR RN (ED eS Pa | ee eo Dee Vc oa me = om [| es bt Lea Dee weats: iby Scene Sed Ey ag ea IG Pome 9 eae Me Ft iit aU ak 8h tal eee ae it See Sor ser Good eel Poel Sta pe Fed He ed RE A | Da MMe BVI | come be DRE o ot oN ica eal PR 3 Ry GE an iO Fa Ve Weed ese) eee i es eae Gan ee 1 2 a (Ee el 1 1 fee 20) | Eaete es Ti} Fae 21a ans hs a ae its sol RA Se eral 1 (Se D7 ese Dies cin sd © | ee ei ove Ul ales oN rea oy | SN ae | ES 1 | | LAS ee a ee ES eae sibs Py ane ea Eran Sy Syed is a ald (eee B) Pee | | @ilgseeeate BO ates: iL [Ea ae Ce ae Fa aS ra (A) [Se al ee ee | | | 1D) 2a eee Shete see: Sod (seen ees Re fea [a leeetoe eee scleeebe leer Suisse [PS eo eRe Be gl PR Gal a 3 1 3 106 | 3,317 INGEST 2e eee eee (Sc ae cea a (eT 0 eae 2 ae Jl A ee a eee. bol y(n 8 (ie A Cal be 2 De ae FY FS Silocaneene (Soe eae i: cel ead abe au Ea Reals Blac ees Mitenls 2, ew boos|ostle ote TS ee | 6 8 Fa et 20 543 Total for , | E Sessom- 145795 )2~ 18 6 | D6 4 oe) 0! | 13 4 1 | i lat | 1/| 1,568 | 54,002 | i | ' | Amerseoinine Spemtan the pround during May: 2... 2 snc ce ene as oe ee cece ciewsae cei cen es days.. 34.91 Average time spent in the ground during June......-...-.....-.-- seas as a eee snares Sen eeS do.... 26. 00 AWerAraruac SpeNE 1 Loe ProuUnd GuUniMe JULY = sci < occ Thdc Jad oe eet Dose Se kes okie Jo ee mente doz a slo28 AMerarewine SHEE LO he round dunTime AWMOUSG< . 22 3-2 << - 22.2 qecece meee ve ted ences memes do Ziedo Averare time spent im the ground during season. ....2-....-.2-2-0d65.- ace cassctcdeececssccenmes do 34. 44 In Table XL the totals from the foregoing tables on length of time spent in the soil are given for more ready comparison. The hori- zontal bars divide the period into weeks, beginning with the third week. The percentages of total adults emerging each week are also shown. Except in the Ohio records, which are perhaps abnormal, and the Georgia record for 1906, comparatively few beetles were out within three weeks from the time of entering the soil by the larve. During the fourth and fifth weeks, however, the great majority of beetles appear and by the close of the sixth week emergence has practically ceased. 17262°—Bull. 103—12 82 THE PLUM CURCULIO. TasLe XL.—Length of time spent in the soil by the plum curculio,; totals for all localities. Locality and date. Youngstown, N. Y.,| New Richmond, Douglas, Mich., 1905. Ohio, 1907. 1910. Days in soil. Fencent pan Percent- “ age o age 0. age of Bene beetles ae beetles pees beetles aes emerging, F emerging F emerging ing. b ing. by ) ing by ? weeks. weeks. weeks. 0. 60 2 | 40.00 7 16 11 14 10 26. 89 5 60. 00 2. 26 5 (aya ee eer | eae eae 50. 85 be OY al ee | ens, ies rcs 37. 29 HOOU ois Beare teen 8. 48 BSG Beets) Reiman oe - 56 GY BCDC aR ROSE Or Coree 5B ae cee oe ae cies eee! OO) Ss aniewenee oaiaeetcee 7 EERIE | COCO Stood errr ett hn beeen tener bene renner - 56 Olas Pas eases 62 sb Sed ceecca Seas Totaliaseoses-e- 331 100. 00 75 100. 00 100. 00 Washington, D. C., 1908. Percent- Beetles fees emerg- | emerging, ing. by weeks. Ay 0.63 4 2 3 8 23 45 26. 48 76 92 48 98 83 106 78 51. 53 87 69 5 53 34 26 45 43 17.14 26 8 9 8 11 5 5 3. 32 3 3 2 2 1 4 doe eee -90 i acne Ys 1,114 100. 00 LIFE HISTORY AND HABITS: THE PUPA. 83 TasLte XL.—Length of time spent in the soil by the plum curculio; totals for all localities—Continued. Days in soil. Loeality and date. Siloam Springs, Ark., 908. Myrtle, Ga., 1906. Barnesville, Ga., 1910. Percentage of beetles emerging, by weeks. 0. 06 10. 01 51. 02 35. 91 1.85 - 89 Pereentage Pereentage Beetles of beetles Beetles of beetles Beetles emerging. | emerging, | emerging. | emerging, | emerging. by weeks. by weeks. | ~ Se NS. at eiooe SN ae eer a | eee ee 0.79 Bf 1-62 fyrcsssciae 467 | ig || leer ee arene 13 1 20 2 } 34 12 62 | 16 49. 49 45 | 69. 95 29 46 32 29 | 24 34 | 42 24 | 43 7 | 63 10 61 43. 58 «8 15. 80 96 5 139 5 189 | 2 209 1 165 | 1 152 2 128 5. 47 5 2. 85 42 1 37 AO re 25 [ 1 14 epee ee 9 1 eras he Aono 3 | - 67 | 1 78 | 6 dacoseceace 1 BES. ARE SS 6 Westepeeeces 4 5 1 1 Pe pS correla EAS USe Gone Barre oreein ce Se cece anc | Hemeeeecee Bs ee oeise < Scene a oee ey Rayale aietaiate Pater clelcte-wistetsla faint tmivloapeseintaie alse ciclamaaiwclt A mc 1 | 1 1 1,77 100. 00 | 386 | 100. 00 1,568 LENGTH OF PUPAL STAGE, AND TIME SPENT IN SOIL BEFORE AND AFTER PUPATION. The data on the length of time spent in the soil do not show the length of the pupal instar, since a few days are spent by the larva in its cell before transforming to the pupa, and after the pupa has trans- formed to the adult, or beetle, a variable time is spent before the insect makes its escape from the ground. ‘This latter period will vary 84 THE PLUM CURCULIO. much, depending upon the character of the weather, whether dry or rainy. During periods of drought beetles appear to remain in their cells much longer than if the earth be moist or wet, as from rains. In fact, in orchards it has often been observed that shortly after a good soaking rain beetles were soon in evidence in large numbers, whereas previously they had been quite scarce. Some data have been collected on the exact time spent in these three conditions in the soil and are brought together in the following tables. Writers appear not to have investigated this point hereto- fore. The data from a practical standpoint are important, since dur- ing the pupal stage the insect would be likely to suffer most from cultivations. Taste XLI.—Length of pupal instar of the plum curculio and days spent in soil as larva, pupa, and adult, Washington, D. C., 1908. D D f D sree o ate ate o ate arva . madieidaalento larva Date of | transfor-| beetle stage Days cy eee oe NER left |pupation.| mation left before res Dee i pire fruit. to adult. soil. pupa- | > ese lene || estat tion. Th, eee 5 eee PET eee June 6] June 19 | June 27 | Jnly. 5 13 8 8 29 hs ee eR nae etre a Pe ed On| lune eS) Sead ore se] mullive 1G 12 9 9 30 Spe aA ere eR RE Dee Ue. d0L-.-.4|) Sune *22) 5 do-2 oe Died. 16 § Dao os | Poe es | oe a eee eens SOs a Une else ed One ae mvilhy ane 12 9 8 29 Fs 82) Ea eee ge en ee ...do....| June 19 } June 29 | July 6 13 10 7 30 (ses ae Sek a ee ost oereie 32 O0es 2 = JuMe 8) |= dole eleva to 12 11 9 32 Uist pet nia) Be MERE Pee OAS ee 52s Os ae 4|- 2200s} ame 2 7a ey AG 12 9 9 30 Rie aes ee ee eee eee ree .--do...-| June 22} June 29] July 8 16 7 9 32 Dea ee AS Come eae do June 18 | June 27] July 6 12 9 9 30 IL) epee ie ee eee eer do June 19 | June 29} July 5 13 10 6 29 See ates Se Sete Se earn do June 18 |...do. July 6 12 11 if 30 LO eat Se C SOE e Pane as June 9 | June 24 | July 3) July 11 15 9 8 32 US Sin eel Aes eae Oe eee Fear do June 22 | June 30 do 13 8 11 32 1S eR a eee Mees era eae SS do Goze. |e=.00- July 7 13 8 i 28 Ht Seats Spee thee cape es do @Oeean|pa2005 do.. 13 8 7 28 UG: 255 Pas hionet mee ten eeeesee do do July 1] July 6 13 9 5 27 ieee one ee ee ee eee |.-.do June 19} June 29} July 5 10 10 6 26 HLS eee oR Fess ene eee do June 23 -do. July 8 14 6 9 29 See A Bh el eee ee do do.. June 30 Died 14 Y | eioectesleccesees DOSE ee eet Lok Aas eee uae do do Tualiy, leony; 7 14 8 6 28 075 |B ace i gat BARE SRE Ooh do do June 29 do.. 14 6 8 28 DD ona waseae easels See ee doles )|a=- do June 30 do.. 14 7 7 28 TOGA as safer eaters Sete Oe eae eae aac aS a OCs ete ca ate eo a ES 290 184 155 587 A-verace for allan Gini G@ual sey .ce eases = oe oe eee ee cee are ee 13.18 8. 36 CMD 29.35 From the table it will be noted that the average time spent in the soil before pupation for the 22 individuals is 13.18 days; the length of the pupal instar, 8.36 days; and the period occupied in the soil as a beetle before emergence, 7.75 days. The average time spent in the ground from entrance of larve to emergence of adult is 29.35 days. These larvee were kept in large glass vials, the soil being a sandy loam. Specimens were kept in an out-of-doors breeding cage in the insectary yard, at Washington, D. C., where the temperature would be somewhat higher than in the soil. Mr. Hammar made observations during 1910, at Douglas, Mich., on a large series of individuals, as detailed in Table XLIT, — LIFE HISTORY AND HABITS: THE PUPA. 85 Taste XLII.—Length of pupal instar of the plum curculio and time spent in the soil as larva and as adult, Douglas, Mich., 1910. = + ; a Days in ate ate o ate larval eye we Fe a Individual No larva | Date of | transfor-| beetle | stage Dy any Paes fa otal ‘ left the |pupation.| mation | left the | before | BMP | Dee eleaes fruit. to beetle. | soil)” | pitpa= | SP2S°*)||2m/sou. |) “son. tion. Ul AAS OCS IAS See June 30] July 11] July 26] Aug. 1 11 15 6 32 os BS Ses ie eee eee) ae do....| July 12-| July 25] July 29 12 13 4 29 MEER em face aise can eaees July 2] July 13} July 27} Aug. 2 ll j4 6 31 ameter toca see seca ae seen [Se do= --|fuly- 21 || Aug. 72) |-Aug. 7 19 12 5 36 De eriaeanie Saez ore cinched ee July 4 |...do. ee COs ers eae eS A; 12 6 35 WEE geet ee eo oe ccc nelese Goze -| uuly, 225) Anjos = 1) Ae. 55 18 10 4 32 Sa SORE G eee an a ge do. -do. Aug. 2] Aug. 8 18 11 6 35 ORO Se ae ea July 6] July 20} July 30/ Aug. 3 14 10 4 28 Uh ee EROS RE Cea ae eee aes eee do. aU bt IPL IF SRG Uo ees al ao (Ole 15 9 4 28 Go mk I ee July 8] July 17] Aug. 1] Aug. 10 9 15 9 33 Petre ee eee eee Le of do--2 =|) July £9) | Anes 2 1 dose 11 14 8 33 12.08.18 Se cee ee eee ee do....| July 20] Aug. 3-| Aug. 8 12 14 5 31 LST LS Se ee 2 Seer en (ee do2---|pJuly +21 |) Aug. 1)) Auge 10 13 ll 9 33 UCL eS ine eae ee doze=-|b--d0e---|) Aug “3 Anes 2 13 13 9 35 WN ie SR Sees oe ee do...-.| July 22} Aug. 2] Aug. 10 14 11 8 33 Jileach a2 5Se seen eeeee ee ae eee does. aibo.do= Aug. 3] Aug. 14 14 12 11 37 Oo ain Se eet Oe ae ee GOsassessdone sdoes 32) Ange. 16 14 12 13 39 i Se leases tee ee July 13 | July 23 | Aug. 8 | Aug. 13 10 16 5 31 Lee oo ei ee ee a --do....| July 24 | Aug. 9 | Aug. 15 11 16 6 33 7 | Aug. 16 inl 14 9 34 8 | Aug. 17 11 15 9 35 See | cates lS: 11 15 7 33 a2 |) Aue: 16 11 15 8 34 ORieedore- = 11 16 if 34 if |sae Ore ll 14 9 34 aed [eae Ore 11 14 9 34 Eee eee Olserye 11 14 9 34 8 | Aug. 15 11 15 7 33 ...| Aug. 16 11 15 8 34 9 | Aug. 17 11 16 8 35 SU lea dore-=z 11 15 9 35 aeaie Gone Se 11 15 9 35 4| Aug. 15 11 11 11 33 8 | Aug. 16 1 15 8 34 RoaeleAnie. CL 12 14 9 35 9 |} Aug. 18 12 a) 9 36 wee GORE 12 15 9 36 234 Noe TG 12 15 8 35 ee eae Osea 12 15 8 35 ...| Aug. 16 12 15 7 34 8 | Aug. 12 12 14 4 30 re Atos alia, 12 14 & 31 ..-| Aug. 18 12 14 10 36 =.) Aue. di4 12 14 6 32 9] Ang. 16 12 15 7 34 See eae. 4 12 NG} 5 32 10 | Aug. 15 12 16 1) 33 ase |- Auge: #18 12 16 8 36 9 | Aug. 12 12 15 3 30 os oes hbtor aly 12 15 8 35 8 | Aug. 18 7 19 10 36 9 | Aug. 12 13 14 3 30 10 | Aug. 18 13 15 8 36 4 === || Aus, 13 13 15 3 31 G}tj 2 Ss os A ee Oe - le do....| Aug. 1] Aug. 16] Aug. 23 19 15 7 41 Fikret SSN oe 5 July 20 | July 30} Aug. 15} Aug. 22 10 16 7 33 il on Soe ae ee BGO ssa eae GOe ns |e do..--.| Aug. 23 10 16 8 34 tah. Les) MESSE Se eee eee -do =00'...- 5) Aug., 14. Aug. 22 10 15 8 33 Hils oe... eae eee Bows =0o. 252) Aner 25) |eAus. 23 10 16 8 34 esas One Oe eae dors sali do.).-|2_-00-= Aug. 21 10 16 6 32 OLE Sop cade eS ee ne lee do. Aug: 1 |:-:do2.2 = |)Aug. 623 12 14 8 34 (ee So ANS Bee SORA eee eee Per G0esaste: dons ssi do. badd Ores 12 14 8 34 (Sh. it Ee Ee BS eel do Bp (o\eegere| Pe ACs Fore al SS does. 12 14 8 34 (il cae ae ae Se do Aug. 2] Aug. 14} Aug. 20 13 12 6 31 UNL Soper July 25} Aug. 3] Aug. 17 | Aug. 23 9 14 6 29 (SRS: ns Se ee eee Pe do)... -.|-4 lO. Satz (bee dox.-.| Aug. 22 9 14 Fi 28 |e icici bo Se oe = eee eae do. Aug. 4] Aug. 18} Aug. 23 10 14 5 29 oe oe CO EEE Oe ae lees do Aug. <7); 22d0eeeale dos. = - 13 11 5 29 SRipget fas Des eer res ns ne ieee 818 960 485 2, 263 AM erar et Oral anGiviGUAl soo - + <<.0 sin so-5-< bn tse sen sce so 12.03 | 14.12 7.10 33. 28 86 THE PLUM CURCULIO. These individuals were also kept in vials under out-of-doors conditions. The average of the 68 examples for the time spent in soil previous to pupation is seen to be 12.03 days; for the pupal stage, 14.12 days; and an average of 7.10 days was spent in the soil before exit of adult, after transformation. The average of the total days in the soil for ail stages is 33.28 days. The range in time in soil before pupation is from 7 to 19 days. The range for the pupal stage is from 9 to 19 days; and for the beetle in the earth, 3 to 13 days. The entire time spent in the ground varies from 28 to 39 days. Similar data from Barnesville, Ga., obtained during 1910, are shown in Table XLII. Records for 38 individuals were obtained from May 20 to July 11, when the last beetle left the soil. The insects were placed in glass-bottomed boxes containing a shallow layer of sand and kept in a dark box under shade out of doors. Taste XLIII.—Length of pupal instar of the plum curculio and time spent in the soil as larva and as adult, Barnesville, Ga., 1910. Days in Date Date of aoe Date ae al Days in | Days as Total Individual No. larva left} pupa- Sain aa beetle left adie pupal beetle days in fruit. tion. | to beetle.| the soil. Sep puree stage. in soil. soil. tion. May 20] June 5] June 14]! June 20 16 9 6 31 Sea is eee see Re do June 7 | June 17} June 22 18 10 5 33 a See a aoe ae ee [eee do May 31] June 8 | June 14 11 8 6 25 Ss eee She a ae do June 3] June 13 | June 19 14 10 6 30 So SN SO ee ol (eee Gonaes =e aoe June 12 | June 20 14 9 8 31 Bn Ree eee Bae |e doeess| Sar dose June 13 |...do 14 10 if 31 Be oe eens See | eee do....| June 4] June 14} June 21 15 10 7 32 ee Se ee | So do June 5] June 15 |...do....- 16 10 6 32 Bs ene eee ose Meee. G0i.62| do... 2|.une 14) Jime20 16 9 6 31 .do 2005-2 oi) June: 155) 2-¢do: <5. 16 10 5 31 .do ...do....| June 14] June 23 16 9 9 34 do ...-do....] June 16 | June 24 16 11 8 35 PA GOne- o| de) 16) doses June 21 17 10 5 32 May 21] June 31] June 11 | June 20 13 8 9 30 do -| June 8 | June 18 | June 24 18 10 6 34 ---do....| June 9] June 19 | June 25 19 10 6 35 -do -| June 12 | June 21 | June 27 Poy 9 6 37 .-do....| June 16} June 25} July 1 26 9 6 41 ..-do....| June 17 | June 26] July 2 27 9 6 42 OH ee gee Sete ene Twine) v4: |e aor ss June 25 | June 29 13 8 4 25 VAN g Sah ae 9 fee ee June 7]| June 25! July 3] July 6 18 8 3 29 DORs he Sa ssea eos ..-do....| June 26} July 6] July il 19 10 5 34 PA eres Tee Cee ar June 8 | June 27 |...do....- July 12 19 9 6 34 DA SS Se Re ee SE |..-do....| June 28} July 7 | July 9 20 9 2 31 Diese aut Soucy been Si dok eet aNido: aeateen dO saees July 14 20 9 7 36 Doe a Ee ese June 10 | June 25; July 4] July 9 15 9 5 29 0} (SA RRS g June 11} June 23} July 1] July 7 12 8 6 26 DAES ee ee Sees ee Ado eae COs ee natily est |Peelorere) 12 9 | 5 26 DOR me senate BR do. KOZ = EE do .do 12 9 | 5 26 SOP ssa e see ae June 12} June 25| July 4/1 July 10 13 9 6 28 Sipe are. Na a ae -2doue AC Ose ate do -do 13 9 6 28 a ee ee ae || do AOE |e do.. July’ 8 13 9 4 26 BO see ce See |..-do....| June 28} July 7] July 11 16 7 4 29 BAe Wo SS Ree | June 13 | June 27 | July 6} July 10 | 14 9 4 27 Sha ee oS eee do. dotseeies dose Bdosce= 14 9 4 27 BS ee ote ets Seal lon do. doz -do.. -do 14 9 | 4 27 Dilcmeminns eho oS ce MoS do AG toes Sd02 22) Jalhy; 1 14 9 5 28 OTA ee ou feel Ae ee a) (ies ey en lapate LE ES te ee 595 340 208 1,148 Averages for all indi- VAGLIAIS Sse eee 5) S28) Oe el on en Oe See ee eee Ce ae 16.08 9.18 5.62 30.89 LIFE HISTORY AND HABITS: THE PUPA. ST These figures show interesting differences from the Michigan records. Thus, the average number of davs for all larve in soil before pupation is 16.08, as against 12.03 in the Michigan records. The average length of the pupal stage at Barnesville, 9.18 days, is notably less than shown for Michigan, namely, 14.12 days. However, adding together the average larval and pupal stages for each locality shows these sums to differ by only 1 day, the lengthening of the larval stage in the ground in Georgia being offset by a shorter period in the pupal condition. In the Georgia records the average time spent by the adults in the ground before emerging is 5.62 days. The average time of the 37 individuals spent in the soil is 30.89 days. DEPTH OF PUPAL CELL. Great diversity of opinion was expressed by the earlier writers as to the depth to which curculio larve entered the soil for pupation, and no very accurate observations on this point seem to have been made. Riley states that they go below the surface from 4 to 6 inches, and remarks that he never found them deeper than 6 inches. Riley and Howard, writing in 1888, state that the larve seldom burrow to a greater depth than 4 or 5 inches. Other writers say ‘‘a few inches,” ‘2 to 3 inches,” ‘‘a short distance,’”’ and one states ‘‘15 to 36 inches.”’ Prof. Crandall was perhaps the first to secure exact data on this point. In 1903 observations were made on the depth of pupz in ground, including 78 individuals secured under natural conditions under trees in orchards, 79 from bottomless soil boxes, and 22 from breeding cages in the laboratory—a total of 179. In 1904 data were obtained on 645 individuals, 24 by digging earth under trees, 298 from soil boxes, and the remaining 323 from jarve pupating in the labora- tory. Using the records for both seasons obtained under out-of-doors conditions—that is, under trees or in soil boxes, sod and cultivated we find that of the total 482, 336, or 69.70 per cent, pupated within 1 inch of the surface, and 475, or 98.54 per cent, within 2 inches of the top of the soil. Prof. Crandall’s laboratory records do not show important differ- ences from those obtained out-of-doors. Some individuals pupated at a greater depth, as 8 at 3 inches, 1 at 34 inches, and 2 at 34 inches, as against 1 at 24 inches, 3 at 24 inches, and 3 at 2? inches, under out-of-doors conditions, due perhaps to a greater dryness of the soil in the laboratory. Messrs. Girault and Rosenfeld, in Georgia, in 1906, obtained records on the depth of pupation of 121 larvee under natural out-of- doors conditions, the soil being a sandy loam. One hundred, or 82.64 per cent, pupated within 1 inch of the surface, and all, or 100 per cent, within 2 inches. Other records on depth of pupation in the 88 THE PLUM CURCULIO. same soil in the laboratory do not differ essentially, though 5 larvee went to a depth of 24} inches, oneto 24inches, andtwo to3inches. The above figures are patter shown in Table XLIV, which includes also records on 40 larve at the insectary in Washington, obtained by use of a soil box, under natural conditions, the soil being a sandy garden loam. Taste XLIV.—Showing depth to which larvx of the plum curculio enter soil for pupation, various localities. { Me laoeal a Fa eae (eo ea eee al ee Localities. q aq q | 3) 3) fe | Se Sei Celery |S 3 = Ei fae ee a ee se ec ele saieea cellule: |: nit nis ost smn n+ na os Pe ni nie rit nil colt | bam! mo m N nN N nN of oD oO ‘= Illinois Ves opeaoone|lbeoae 45 55 40} 19 16 3 UL 2) srs tall se tlhe eal eaten | Meet eee 179 LOOSE Seinen 48 137 100 91 50 77} 39) 51 14} 15] 12 8 1 2 645 Georgia: 1906... -- 34 61 34 21 23 11 17 10 5 IM asose 2 Sars eer 219 District of Co- lumbia: 1905...- 1 3 7 | Ky) 6 ZL ate 1 1 See 2)1| sere |----- 40 Totals. 4- 83 | 246 196 159 | 102 110 | 61 62:| 20 |- 17 12 12 1 2 | 1,083 Percentages. -...-- 7.66 |22.72 |18.10 |14.68 |9. 42 |10.16 |5.63 |5. 73 |1.85 |1.56 [1.11 |1.11 We 09 \0.18 100 Of the total of 1,083 larvae, 684, or 63.16 per cent, pupated within ‘1 inch of the surface, and 1,019, or 94.09 per cent, within 2 inches of the surface. These figures show that the great majority of larvee pupate comparatively ciose to the surface of the soil—within a dis- tance of 2 inches—a fact to be remembered as bearing on the possi- bility of destroying the pupz by timely and pr Opes cultivations, as will be later discussed (p. 176). SOIL CONDITIONS AFFECTING TRANSFORMATIONS OF THE CURCULIO IN. THE GROUND. Probably no one natural factor, aside from abundance of food, exerts a greater influence upon the welfare of the curculio than the condition of the soil during its occupancy by the insect, especially the degree of moisture. It is a matter of common observation that the beetles may long be retarded in their appearance from the ground by drought and that after a soaking rain they will come out literally in swarms. The necessity for adequate soil moisture for their suc- cessful underground transformations and their emergence is doubt- less the most important single influence which has prevented their spread into the arid regions to the west. As shown under the head- ing of geographic distribution, the species has not extended its range much west of the one hundredth meridian, which marks, in a general way, the beginning of the arid region. Some experiments have been made at different times, but espe- cially during 1910, to secure data on the influence, on the transforma- tions of the insect, of different kinds of soil and of normally moist as compared with dry soil. tia iii LIFE HISTORY AND HABITS: THE PUPA. 89 In Table XLV are shown results from three root cages. In the first the soil was kept normally moist; the second one was moist at the beginning of the experiment but was allowed to dry out; in the third cage the soil was dry at the start. June 4, 20 larve were added to cage I, 20 to cage II, and 12 to cage III. Taste XLV.—Lfect of moisture on transformations of the plum curculio in the ground, Barnesville, Ga., 1910. Date z - ec ae Life of | Date of Life as| Total peor Treatment. es a ae larve | transfor- oe ot adult | life in : il BOE *| in soil.) mation. BS. * | in soil. | soil. Days Days. Days. | Days June 4 10 | June 23 9| July 3 10 2 SAGE [555 10 | June 22 8 do... 11 29 ..do. 10 | June 23 Gi See We. eae Ie wees --do. 10)|-e2do:==— 9\July 3 10 29 ‘ Stokoe Deedes ae 8 | June 30 7 26 “17, ..do. 11 | June 22 (0 See serc en peared aetmerce eon ecpinormally oe tel lone 11! June 23 8 | June 29 6 25 mie dose 12 | June 24 8| July 1 7 27 Addl iiine ss 14 | June 26 8 domes 5 27 dote=se=2 Gore. 14 dO:s..6 8| July 4 8 30 -do. June 19 15 | June 27 Ba Sak oer Sees cent neene do....| June 20 16 | June 28 8 | July 7 9 33 -do July 3 29 | July 11 Bil bepe ee Se I ee hese Ee ipa ate Moy #2 (eee ale ea ha (ee lfc eee eae = LOGE |S ape sete 73 255 ACV ETA EC Seca noo ene e|s oe ine IE S10" Memesemsae Selah aie oseee ok 8.11 28. 33 la as June 4] June 13 9 | June 22 On ae oe oe trainee Imes Dae do esdOuae—* 9 Goer Qi | aie ew eee See ee lee eee Siacee ee do ~adOso cee 9b S22 doss-- 9| July . 4 12 30 Bers ioe At start soil nor- ||...do....| June 14 10 | June 23 CO [vee 2 ea eral eer rel ere nee Wee oraicns mally moist but |j...do....]...do..... 10 | June 22 All oan, Se oe Se ol eee nce Se aS ee Geese. |{) allowed! ‘to dry: |)\....do..-.|_-.do..... 10 | June 23 Oy AS ae tee odlloceeeeoal eae aan Mista aaieiele out. eden n= sOOre-. = OES COL =. OS | eee Ree lee Sees Soares do June 15 11 doze 8 leccesscacdlobesccadisnecdone Le do EGO=s ene 11 |} June 24 Dy per aera. Poe ere Ne itd) eas oS do June 16 12 | June 27 LIAR | Reet oe Cee | AW ee eee | ee a Daye PROTA cee |S cee cert sactonaveee AKG See eee OOM co eee 1 30 PAY CVS E ea ese cece mcysew ae elc LOW eles ONO} ars soto 12 30 ee aera - - , |fJune 4] June 14 10 | June 23 OU Eee. ee leas eee Recs Ts ey nail \soil entirely dry... { do doe. 10 adores P| en IG Sy =| cg Dee scone ROA se eee ee SS DOV Eee a ae 1h Seeoe ceed aaa aa (eee oe IAW EEARO sey oo | See oe cise le lect LOG Bese es O lste sees Is cece ae As will be seen, 13 larve in cage I entered the soil and reached the pupal stage; only 9 adults, however, emerged. In cage II, 10 larvee passed the pupal stage, but only one adult succeeded in emerging. In the third cage most of the larvee were unable to work themselves below the soil to any extent on account of dryness of earth, and by June 13 several were found dead, evidently drying up. Only two individuals reached the pupal stage, and no adults emerged. A series of observations was started on larvee placed in‘soil in jelly glasses, as detailed in Table XLVI. 90 THE PLUM CURCULIO. Taste XLVI.—Effect of moisture on transformations of the plum curculio in the ground, Barnesville, Ga., 1910. SOIL KEPT NORMALLY MOIST. Per cent at Z Beetles Average a Jar No. Larvee. emerging. | time in soil. ao StI Days 11S. Sea Gene REE SEs nomen ortens stoves ekwetcmochoter 16 15 25.53 93.7 Dt: 35 0 Ee eee See SSG spa oracle Shes acsocbeodveuradarcs- 13 12 25.50 92.3 Why: = aS Neen e eee at eee mS os She ceSoeeec aecasesecee see 11 11 25.27 100.0 1) eee ec ARE otae nine ee Res eee Soc 17 13 26.15 76.5 AZ) 0 PRA ae tee nhac ane srs Seca cepoarnas aoseecTs 2 8 8 28. 12 100.0 >. (SUR ae EE ty To et Sen near eA BA Neaop Se esas: 15 12 25.91 80.0 D411 0 Rt ee tok 2 As oe ee eee pence os taroaosoto4 12 11 24. 00 91.7 SOV LD 2 32 bee Saco eee ene Tal | i SP Nie kor fod mS a ees eneg IA es emcee |e See me ee eer ee eee me Ce) eG LOU 2) 88) Onl eceea ee amen seal ose etc pee Gee hee : 8.. =s65 9... YF | dee SAC RIS PASCO GSO e | MEO ||E a Mlle 3 Se eis HIRE oes Bei HE espace) aadok oc LOE PNW CU eR 1s ee lil I ae eee Sar Aes ane eco eeodee| eee nteee 1 Pace me oe he ON | ier aC cael en COnllen oven cam eer teracetas | ete seers ie One® Se Ouiosee sec I 9 | TBSS © | LON Re reenter 1Se: Phe Sb Recerca) mee l0 eee ee el Sopa ned eer ecene| Eo Saebiis se 14.. ae (Ph 0) WRU TRE rere BS )at | me 20 es SL Ree Se Sele Res Boel Boose ea 15.. WS ociereecoc, Van Mee EE SPA a ree 5 || -a Peso al Rael eile tO lene! Jnl lO aceces| be el 8 aE she om nbs «Qe her es eee aac SS n aoe ee Wie Si aol Se) oe) BeenOs || Remecoeace enc eere ms nemer eee ot mentees soe c memes ihe chp Elgeeiommeaec| oe GaN 8 RRR USC RSS onal Roeser apenas seared peeks sacc 105 Opie AE Ns TASS Sal Qos Levees eee So asco scwl ade | a eset ee a eeee eee i ce a esd AOS eo anos select are poco ok cel ame 2 ye eo 21... ST STA tee HN ried Se aSornee! Meret sc Me cer ecisel elmer eee ee DA on enemy ent tees Ai gee ral ars, carantte 235: 29 (ae 5 25: . 21 | ..eeeeeeee|eeeeeeeeeefeeeeeeee P00) (ee 26... 16 | Zhe. 13 2a 4 3 as a erro ee areas | poeta ee |Sacte sao: son. 1,718 1,803 1,510 102 31 iene ENS fee ees Total. 194 | 194 | 47 102 The data do not show the entire range of time over which beetles may emerge from a given locality, but they indicate about what hap- pens in a particular orchard. Later records could doubtless have been gotten had other fruits been used as a source of larve, after the gathering of the peach crop. The Barnesville, Ga., record is perhaps the most nearly complete, since at that place there is little fruit available for the curculio after the harvesting of Elberta peaches. This record shows an interval from June 6 to September 28 during which beetles were emerging— a period of 114 days (see fig. 21). But from larve from some late seedling peaches beetles continue to emerge up to November 9, giving a total period of 156 days. Only the cold weather prevented still further emergence, since on November 10 there still remained in the soil fully matured adults as well as many pup and even a few larve. These were from a batch of 107 larve from seedling peaches, the last to be secured. The larve left the fruit September 18 to October 15, and 15 beetles emerged October 19 to November 9. The soil in the box was examined November 10, when there were found 6 beetles ready to emerge, 28 live healthy pupe, 5 live 94 THE PLUM CURCULIO. larve, and 1 cocoon of Triaspis curculionis, var. rufus. It thus appears possible that some few individuals may pass the winter in the soil, both in the adult stage and as pupe, and emerge the follow- ing spring. During 1905-6, at Fort Valley, Ga., adults were reared as early as May 22 and as late as October 5, an interval of 136 days. In this vase the food for the late rearings was Cratzgus. SUNE- Soe ae oP, agi DORE ae UE Pau se ee ze RCE ‘Vel | Loi | | AL | Mee rele Fig. 21.—Diagram showing normal emergence from soil of beetles of the plum curculio for the season at Barnesville, Ga. (Original.) ty S NUMBER OF BEETLES EMERGING > Ss AS) At Siloam Springs, Ark., the interval of emergence, June 11 to September 3, includes 84 days. Later miscellaneous records of emerging adults reared from apples, however, were, up to October 23, giving a total emergence interval of 134 days (see fig. 22). SON ————— UE _———SS— SEI es 6 TS 6 /6 ey 6 eal 26 eae oo ia an Ht Co : ee < Fig. 22.—Diagram showing normal emergence from soil of beetles of the plum curculic for the season at Siloam Springs, Ark. (Original.) ea “NUMBER OF BEETLES EMERGING The Washington, D. C., records show an interval from June 25 to August 21, 57 days. Other miscellaneous records for that locality give adults as early as June 15 and as late as August 30, or 76 days. Unquestionably adults are emerging even later. aE LIFE HISTORY AND HABITS: THE ADULT. 95 The Douglas, Mich., records, as pointed out for the larval emer- gence data, are manifestly incomplete, especially as regards the latter part of the season. They do, however, show the emergence of beetles from all larve from peaches regularly collected throughout the season, as previously shown. ‘The interval here is only 23 days, from August 1 to 23. Incomplete records from Youngstown, N. Y., give for the earliest beetles July 18 and the latest October 6, a period of 80 days. At North East, Pa., the first emergence was noted July 15, and beetles were reared in confinement up to August 21, and unques- tionably appeared much later. The period observed, however, is 37 days. In Illinois, as stated by Prof. Crandali, earliest beetles were reared July 17, and continued to emerge until November 7, a period of 113 days. His observations were made on apple, on which fruit the insect would have opportunity for late ege laying, which would not be true in the case of peaches and plums in the South. Unquestion- ably the Illinois records more nearly show the period of emergence for the Northern States where suitable fruit is not at ary time wanting. The above data are shown below in tabular form. Period of emergence of beetles. Days. pense Wee eo to NOM Os. = oak a Seo Bee et he cen he SE's: Lk Aaa Mem llptO.OGi a Agent ets sioke eis so ea ees bee es ak 134 Visiriec on Columbia—Inmew'5! to Aug? 30. 6.2 22.52.2220 2 eee 76 Micharan—vne® tito: Amer 23s 2 Us fk oe ek eet ols Lee a Newel for ek JiullvaliS ton@ cen Geert eee Sar se wire ey eee Re 80 Pilon bul eA (tO INOW g2n2 522 e2 pea Sees toe doa d= eb Sas cn depos 113 PROPORTION OF SEXES. The proportion of males and females was determined at different times, with overwintering and newly emerged adults. In a lot of 80 beetles reared in confinement at Washington during June, 1905, 30 were males and 50 females. In another lot reared as above, 21 were males and 45 females. Of 140 adults jarred from trees in May, 1905, at Arundel, Md., and hence overwintering beetles, 70 were males and 70 femaies. At Myrtle, Ga., in 1906, of 200 beetles jarred from trees May 14 to 21, 83 were males and 117 females, and of those taken May 22 to 30, 73 were males and 107 females, a total of 180. One hundred beetles reared from various fruits during May and June gave 51 males and 49 females. In a lot of 175 beetles reared from May 28 to August 12, 81 were males and 93 females. In a lot of 840 beetles jarred from peach at Fort Valley, Ga., in 1905, 339 were males and 501 females, 96 THE PLUM CURCULIO. Considering the proportion of sexes of those reared, there are found, of the total 681, 306 males and 375 females, a percentage of females of 55. Of those jarred from the trees and which had thus passed the winter, there is a total of 1,180, of which 688 are females and 492 males, a percentage of females of 58.3, showing a slight increase in mortality during winter of males over females. CHOICE OF FOOD BY CURCULIO. Practically all writers agree that plums are the preferred food of the curculio. Under orchard conditions, where several fruits are present, as apple, plum, peach, etc., taking the season as a whole, the plum is perhaps somewhat more injured than the others. Varie- ties of plums, especially Japanese sorts, are early to develop fruit, and consequently are first attacked by the beetles, and on these they seem for a while to concentrate. With the development of peaches, apples, and pears, these are also attacked for feeding and ege-laying purposes. In general, however, it is undoubtedly true that plums are the favorite food of the curculio, and are also pre- ferred for oviposition places. Attempts have been made to obtain data on the fruits preferred by the insect by supplying beetles with various fruits at the same time. Tests were made by Mr. Girault, May 17, 1905, in which 5 fruits each of plum, peach, quince, and pear were placed in jars and each supplied with 10 curculios. Upon examination, May 20, 72 hours later, results were as follows: On plum, the egg and feeding punc- tures were so abundant as practically to cover the whole surface of the fruit; on peach there were numerous punctures, but they were less abundant than on plum; on pear there were no punctures on fruit, but a few were on the fruit stems; on quince no punctures were seen on fruit, but a few were on fruit stems. Expressed in percent- ages of injury, plum would be 100, peach 50, pear 10, and quince 10. Mr. J. H. Beattie placed 100 beetles in a jar containing foliage of peach, plum, pear, and quince. Two days later peach leaves had been riddled by feeding; plum leaves were moderately eaten; the quince showed a few feeding marks, while the pear foliage had not been touched. June 7, 1906, 12 beetles were confined with two large Elberta peaches and five wild plums. After 12 hours, punctures were noted as follows: On plum, egg punctures 37, feeding punctures 30; on peach, no feeding or egg punctures found. April 23, 1906, 15 curculios were confined under a jar with three fruits each of apple, peach, wild plum, pear, and cherry. The results EE LIFE HISTORY AND HABITS: THE ADULT. 97 gave a preference of fruit, as shown by feeding and egg punctures, in the following order: Apple, peach, plum, cherry, and pear. Further data are given in Table XLIX. TaBLE XLIX.—Attractiveness of different fruits to the plum curculio. Lot I. Lot IT. Lot III. Lot IV. | Punctures. Punctures. Punctures. Punctures. Dates. i——_—_--— | Dates: aaa RUCK Si ae Apple. | Peach. Apple. | Peach. Apple. | Plum. Apple. Plum. | May 1.... 5 5 | May 13.. 10 10 | May 20.- 5 5 | May 28.. 5 5 Does 9 11 14.. 10 11 pales 9 11 29... 10 | 10 Dees 13 Ga 15.. 8 12 22... 12 8 30. . 10 | 10 aeeee 13 7 | 16:2 iit 9 23... 12 8 3l..| 5 15 a 14 6 yaa 11 9 24.. 12 8 | June 1...| 8 12 Gisce 13 7 18.. 11 7 25... 10 10 ya 13 | 7 ifoace 17 3 19:5 10 10 2622 8 14 heal 11 | 9 Sone ili) eee OED 7 3 7ee 5 5 Total. 94 | 46 Total. 71 68 Total. 75 67 Total. 67 | 73 | A total of 165 punctures is shown for apple, as against 114 on peach, and a total for apple of 142 against 140 on plum. The preference of the curculio for smooth fruit is shown by an experiment by Mr. Girault in 1906. In a jar were placed 20 beetles, 8 males and 12 females, which were supplied on several successive days for four-hour periods, with 3 normal peaches and 3 peaches from which the fuzz, or pubescence, had been removed. The results are as follows: TaBLE L.—Showing preference of plum curculio for smooth versus fuzzy peaches, Myrtle, Ga., 1906. Normal, with pubescence. Pubescence removed. Fruit 7 ie No. Egg Egg Feeding | Egg Egg | Feeding pune- {punctures punc- pune- (punctures) punc- tures. |witheggs.| tures. tures. (witheggs.| tures. Apr. loss eeeatpnl|saees cele 2 16 13 2 2 1 1 2 15 9 4 3 4 11 7 3 Cy El eee ers See se: gene = Sore ame 1 1 5 Belle ae 11 10 2 6 |. 1 13 12 6 WAG 1 11 10 9 8 |. 2 13 11 7 9 |. 1 8 8 oe 10 3 4 3 5 els 1 9 9 5 12 3 4 | 4 3 J 2 ee ee 3 2 | 20 116 | 97 56 | | | A total of 3 egg and 20 feeding punctures is shown on the normal fuzzy fruit as compared with 116 egg punctures and 56 feeding punctures on fruit from which the hairs had been removed. 17262°—Bull. 103—12——7 98 THE PLUM CURCULIO. EXTENT OF FEEDING OF THE RESPECTIVE SEXES. The extent to which feeding is done by the respective sexes of the eurculio during their lives is shown in Table LI. Individuals of each sex were separately confined and each beetle supplied daily with 4 wild plums, examinations of the fruit being made daily. Taste LI.—E£xtent of feeding of each sex of the plum curculio during the season, Myrtle, Ga., 1906. May Dates. Feeding punctures by males. Feeding punctures by females. tle tle No. 8.|No. 1.|No. 2.|No. 3.|No. 4. Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- tle tle tle tle tle tle tle tle tle tle No. 1.|No. 2.|No. 3.|No. 4.|No. 5.|No. 6.|No. 7. 3) cM eae 4 uf 1 2 3 13 12 3 4 3 2 1 TY [Nee ga 2 3 5 2 4 2 2 DM tase eae) 1 2 5 4 3 2 2 3 LG Ese S| eres 2 8 2 2 I eseeeee 2 1 1 An ene ee 1 4 8 7 6 6 1 2: 1 Ht 2 5 1 2 3 5 1 1 3 if 8 2 2 1 2 1 1 1 3 2 2 2 1 1S) [sree ee! 3 1 1 2ilab sone 1 5 4 4 2 3 Valtivaces | ep es aoe 5 heehee 4 5 11 4 3 2 1 1 4 4 5 1 4 3 2 2 1 1 5 3 2 2 5 2 3 1 2 1 3 5 1 2 5 4 1 1 O78) mee 12 4 oonee 1 3 2 2 1 u 1 2 3 2 3 4 is Wer sAe 1 4 3 1 2 4 5 6 Bi] Cae 1 i | ie SP 7 6 1 2 POU IG eee 1 3 1 8 8 3 3 (ayy epee 1 il 3 2 3 5 2 3 sal ee eg a | 1h eee toe 1 2 eae 2 1 LY estes Ibi eee 7A ees 2 8 2 5 Fol eget if 1 2 1 3 4 1 1 Bs eee 2 2 3 2 4 5 3 3 7 | PESOS aeece 1 2 2 8 3 2 1 7 ee 3 ly S255 | Cee 1 5 3 1 | al a 2 1 1 3 5 5 1 4 i Fa ee 1 2 2 2 6 5 1 3 iP | eso 1 Jo) Saseck|ssenan 5 6 3 4 PF ec e 1 1 2 1 6 7 7 if 1 A Ree el ees 2 6 4 3 2 4 4 1 7 7G es 4 4 3 2 Bal Ramat. Oi ibesees 1 7 4 8 5 3 Hy Beare 6 1 3 2 6 4 2 Zz, Sia seeeee 4 4 2h sete 9 4 2 2 7 Ml aS ae 1G) bes a ea Ieee 5 4 12 1 3 1M ees ee 2 1 1 4 6 5 1 3i|Sn saree 5 2 Zi see kee 5 6 2 1 Pl eee OMleeewse 2 Qolateses 7 1 al) eae Roce ocace 3 1 1 6 4 1 4 Drie esee 1 Ls] Soceee| eee 4 5 4 3 AY). casks 74 | a 2 2 6 12 3 4 Bo |Sacaee 5 1 3 3 i 14 1 7 P \iecace 3 1 1 2 5 a 5 5 Ea See 1 2 2 2 4 6 1 2 Suleaseee 1 6 3 1 7 8 5 1 oleae 1 3 2 oes ee 5 2 4 4 Guile eeees 5 3 A Wee ercore 2 1 1 8 2: |oseeee 2 4 1 a 2 4 1 6 10) facehc 4 1 2 3 5 4 1 5 Oh | Seema 5 1 Wests sae 4 6 4 3 cee eecesleeees 3 3 3 4 3 4 2 Gia eee 2 2 3 5 1 5 4 Bilecnsae esess eBeos Snes 2 3 1 Bi leeeece Gulzoeeas 6 1 1 3 5 1 2 1 De De ts \seaeees 2 5 | (2) 4 3 (Yel Bea eae rl eee 4 1 1 Ses 4 4 2 2 1 Soe 4 4 Lcotee| ssh | Ssee eee 5 8 4 8 1 Died. 8 7 4 4 5 5 5 3 3 6 3 13 3 8 3 3 4 1 4 6 5 4 8 11 8 3 3 8 8 4 2 5 8 3 19 11 9 ni | 2 3 3 3 1 1 S3| ssecee 6 3 1 2 2 2 2 2 3 3 10 3 3 1 4 7 5 4 8 1 4 6 13 14 10 3 5 2 2 2 il 2 9 7 2 6 6 13 3 3 3 2 1 4 1 3 siseisee 2 2 2 3 2 4 8 2 3 3 4 2 i 7 4 ASsoce 2 SA2SS2 3 sacs 16 eae 14 Beane 13 LIFE HISTORY AND HABITS: THE ADULT. 99 TasLe LI.—Extent of feeding of each séx of the plum curculio during the season, Myrtle, Ga., 1906—Continued. Feeding punctures by males. Feeding punctures by females. Dates. | | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- | Bee- tle tle tle tle tle tle tle tle tle tle tle tle No. 1./No. 2./No. 3./No. 4./No. 5.|No. 6./No. 7./No. 8.|No. 1./No. 2.|No. 3.|No. 4. | | 22 2 1 8 | 22 if 1 6 i 8 2 5 8 BN Send 3 2 7 2 4 19 LOM So5.2 5 15 4 seenst 9 3 8 1 9 3 5 1 5 8 2 4 8 5 2 2 10 3a eS | Bee 3 1 7A Be ee HEA aoe 3 2 5 2 Jee chee (*) Qi \aeeece eee wa] a cme nc lec ew welecewee|- == one July 1 Died. 2 No record. The individual records show that the females feed more actively than the males. Most of the males had practically ceased feeding by June 11, although the females continued to feed freely during the rest of the month. The average number of feeding punctures per male, excluding No. 4, is 135.55, as compared with the average of 355.50 for each female. OPERATION OF EGG LAYING. The process of egg laying of the plum curculio has excited the interest of many observers, and it has been frequently described. There is much variation in the statements as to time occupied, se- quence, and relative time of the various acts, etc. Many writers have not distinguished at all the separate steps involved, as, for example: As soon as the plums, peaches, cherries, and apples are set the curculio commences operations, imprinting the familiar crescent and placing an egg inside, 100 * THE PLUM CURCULIO. Riley’s account of oviposition is, however, much more complete, as follows: That the egg is deposited in the following manner, the whole process requiring about five minutes: Having taken a strong hold on the fruit, the female makes a minute cut with the jaws, which are at the end of her snout, just through the skin of the fruit, and then runs the snout under the skin to the depth of one-sixteenth of an inch, and moves it back and forth until the cavity is large enough to receive the egg it is to retain. She next changes her position, and drops an egg into the mouth of the cut; then, veering round again, she pushes it by means of her snout to the end of the passage, and afterwards cuts the crescent in front of the hole so as to undermine the egg and leave it in a sort of flap, her object apparently being to deaden this flap so as to prevent the growing skin from crushing the egg, though Dr. Hull informs me that he has repeatedly removed the insect as soon as the egg was deposited and before the flap was made, and the egg hatched and the young penetrated the fruit in every instance. Prof. J. M. Stedman also described the process: In making punctures for the purpose of depositing eggs, the females also eat the tissues of the apple, and this is probably the reason why during the egg-laying season they do not make as many purely feeding punctures as they do earlier and later in the season. The female first eats a small hole through the skin and then eats the pulp back about one-sixteenth of an inch, thus making a small cylindrical hole, usually quite parallel to the skin. She then turns around and deposits an egg in this hole, which is just large enough to receive the egg nicely. Having accomplished this, she then eats the tissue while cutting a small crescent-shaped hole through the skin and into the pulp so as to partly surround and partly undermine the egg. In Prof. Crandall’s studies many attempts were made to secure data on the entire operation, but owing to the difficulties of so doing, three instances only from start to finish were observed, as follows: In the first observation, the female moved about the apple for several seconds, keeping the end of her beak in contact with the surface, as if seeking a favorable spot. When the exact spot was decided upon, the minute jaws at the end of the snout began a rapid movement which quickly made an opening through the skin. This opening was no larger than necessary for admission of the tip of the beak. No skin was re- moved; it was simply torn and thrust aside to give access to the pulp below. Later, as the excavation proceeded, the broken skin was seen as a sort of fringe around the beak at the surface of the fruit. As soon as excavation in the pulp was commenced, the beak was deflected backward so that the work was carried on under the insect, just beneath the skin and nearly parallel with the surface. As the work advanced, the opening through the skin became slightly enlarged by lateral motions of the beak. The pulp was all eaten as excavated. During the process the beak was not once withdrawn, nor was there any cessation of motion. When the excavation of the cavity was completed the beak was withdrawn by a quick motion, the insect turned about, adjusted the tip of the abdomen to the opening and deposited an egg, which was forced to the extremity of the excavation by the ovipositor. The insect now rested without motion for two minutes; then, turning again, proceeded to cut the crescent in front of the egg. This crescent puncture was not wholly a separate punc- ture, but, starting in the original opening through the skin, was cut laterally in either direction, partly by the jaws and partly by crowding the beak first one way and then the other. The direction of the beak was but little deflected from the perpendicular and the cut was made as deep as the length of the beak would allow. The pulp torn LIFE HISTORY AND HABITS: THE ADULT. 101 away in making the crescent was eaten, just as was done in excavating the egg cavity. The crescent completed, the insect walked away, drew the legs closely under the body, and settled down, apparently to sleep. The time occupied in the process described was distributed as follows: Minutes. LO SSEEST DRA ae SC ly eS ge ee Se 9 LD SSCS OE een ee eee 1 ING Soe Sho ee Ger - So AR BOC OE Ae BROCE eee ete eee ieee 2 ruin sue: CLesCeMimereey eet tems ae Seeley Hee Sie we mie 34 BIE G (rel eens eer erence tet te ere PAY eS Se tors Chala genial Soha re 154 The egg cavity was cylindrical, with a rounded bottom, and by measurement was found to be 0.04 inch in depth. The egg when deposited very nearly filled the cavity. The second observation of the complete process was nearly identical with the one described. The insect spent no time in choosing the exact spot, but went to work at once. It worked in a more leisurely way and did not excavate as deep an egg cavity. Eleven minutes were spent on the cavity, 2 minutes in depositing the egg, 2 minutes in rest, and 4 minutes in cutting the crescent, a total of 19 minutes. The egg cavity measured 0.035 inch in depth and was completely filled by the egg. On completion of the process the insect moved a short distance and immediately began a second cavity. Essential differences from procedure in the two preceding cases were noted in the third complete observation. Excavation of the egg cavity was the same, except that it was deeper in the pulp and of greater depth. After depositing the egg the beetle turned and with her beak worked the egg back to the bottom of the cavity. Then she began tearing off bits of skin and pulp, which were carefully packed in, above the egg, until the cavity was full. Following this, the crescent was cut in much the same manner as in the preceding cases. Then she appeared to make a final inspection, and added some further packing above the egg. Finally the work appeared to be satisfactory and she walked away and began a second puncture. The time consumed in this process was longer than in the others, and was divided as follows: Minutes. Ca ALInS CPi CONG eas ae ee cee ce he ee esc. 12 IDE OSTLIND CRC. sas sent oes eyo ere Ne BG dE i ily yh 14 iInicing the ese with thipmeakes = 20s oes fhe gd. fs se! oie eae 2 eeRaAn ENG GaNIE Yio bse Pe eee ee i eee at 4 emda tne: Crescent. asa Moma oie Se et ad op ete ck Lye 4 HIME In TOUCHES 6... ances ga 53 Se ate eco we eel Loe 3 Hipp ewe 13s Jeet ae Rey Need eae ee OP ob 264 Mr. Johnson observed the operation of egg laying in 1905 at Youngstown, N. Y., in a Niagara plum, from which the calyx had recently fallen. The excavating of egg cavity, placing of egg, packing of cavity, and cutting the crescent was done without a pause and occupied 10 minutes. According to the observations of Mr. J. H. Beattie at Fort Valley, Ga., in 1905, a beetle was occupied 1 minute in making the egg cavity in a plum, after which, turning around, it deposited an egg in about 5 seconds, a few seconds more being required in pushing the egg into the cavity. However, in cutting the crescent 6 minutes were occupied, a total of a little more than 7 minutes. 102 THE PLUM CURCULIO. Mr. Girault observed a beetle at Myrtle, Ga., May 7, throughout the entire operation. This individual had been previously starved and was furnished with a fresh wild plum upon which it climbed at 4.36 p. m., settling on the side. It carefully examined the surface of the fruit before beginning oviposition, as follows: Minutes. Egg cavity begun 4.43. Eee cavity finished’ 4:6) 22220 ones ee ee ee 8 Ege deposited 4:51-1fs4. (22d 22 Se ie eee 3 Ege pushed:in cavity 4 pigeon ee 4 Packing ég¢ cavity 46523 -49 UTAe Po ona oe eae ee ee 24 Began crescent’ 4.50-2..222e. Ss sei se Sitg some ss See Re ee eee on eee Crescent finished 6.08.22 -e- saeee ae ee eeete ee ets Setropee 13 Total soos co tk ak eae Soe ee see eee ee nee ee era ace 244 During the process the body was in an extended position, legs well out grasping the fruit, and while excavating the cavity the body was at an angle of about 45°. Difficulty was evidenced in holding to the fruit. The tarsi were continually being lifted and extended, and applied to the fruit, and this was followed by a drawing motion, to engage the claws if possible. The antennz were motionless, the scape lying alongside the rostrum. At Barnesville a beetle was observed ovipositing on plum, April 11. Its time record was as follows: Minutes. Beak inserted 9.47. Beak withdrawn and ovipositor inserted 9.49.............---2------ 2 Ovipositor removed 9/49}. 4023.52 2 ew ce eae ee ee 3 Packing cavity, umtil9, 52223. 222 see oe ee ee ee eon 23 Beran cutting crescent 003627 5 ene eee ee eee Crescent completed, W107 ~~ 2. .sc. 5. oeirating tere os os Ree eee Netual time occupied im, cutting 2 25.-.2cesn- so tet eee eee 36 Beetle rested 6 times while cutting crescent, a total of............. 39 Potal intervals. sasccces cies cee eerie e eee ee eee 80 Also at Barnesville a beetle was observed April 20 ovipositing in young peach. At 9.30 the hole was started in fuzz, the beak being worked down full length. At 9.41? beak was withdrawn and the ovipositor inserted. The ovipositor was withdrawn at 9.42} and the egg pushed down with the beak. The beetle withdrew at 9.46 without filling the hole in the fuzzy covering of the peach as usual, the total time being 16 minutes. Another beetle, ovipositing on plum, inserted the beak at 9.08, the egg cavity was finished and ovipositor inserted at 9.094, and the ovi- positor was removed at 9.10. After packing the egg cavity the crescent was begun, which was finished by 9.28, a total of 20 minutes for the entire process. LIFE HISTORY AND HABITS: THE ADULT. 103 EGG AND FEEDING PUNCTURES: POSITION ON FRUIT AND VARIATION IN FORM. The position of the egg puncture on the young fruit, as would be surmised from observations on the process of oviposition, is deter- mined in a general way by the part affording the beetles the best anchorage for their feet during the work of excavating the puncture and crescent. This position will vary according to the age of the fruit, and also according to the kind, as whether plum, peach, apple, or other species. Some data were secured by Messrs. Girault and Rosenfeld as to the location of egg and feeding punctures, which are set forth in Tables LIL to LIV. In the case of the peach, it proved to be difficult to separate positively the two forms of punctures, and these are considered under the same heading. TaBLE LII.—Location of egg and feeding punctures of the plum curculio on wild plums, Myrtle, Ga., 1906. | Location of egg punc- Location of feeding Fruits examined. tures on fruit. 4% | punctures on fruit. F E 5 s|3 q mila Dates of examinations. 8 3B 5 z 3 a 5 zg end =I o1e !] 4] bo On esomct From 3 wlal¥|ag wloa |e i=") 4 oO 3 = : v1 . o Es} — Shy Pech | aoe ese ee a eI ral | io re See | olatia|/Sia)/a13)/alia/3)1a] 3 A/a Al/OoO;sa/Al/seian fs ayoy;s | a TT eGis 2 oats PPA e24 || alle | eee ee ll Pll Berens [Pa b 3 2 BdOto. ac AR AD) ee ieee ll) 32 1a Si eee en 6 1 OL ee ae LE pce || 3 6a) | 25) al 1 Mase Groundeea4s5|ta2) es eons 45ers) Lau Te | eae ee 8 Treees 23.2. 76 | 36 Ze oy Las Loo Sleeps 1 Ground.../101 | 45 | 8 | 10} 21 | 17 | 10 |--..|- ee) tiga 9 GOs=reee || alo Z 4 8 | 25 6 Sit 6 Trees As. Te eSe Mea eLoel menesee tred Lop | = 1 1 2 Ground 102 | 17| 14) 20| 5| 46] 5 Pal 2 Treewscc 2 ASs | MASS esa esal lsu de ONAN a 4 dow. 2-4 62 8 | 14 5 1} 34) 3 1 1 1 Ground.../ 58} 2] 7] 3] 11] 45) 6 1 5 Treas sts: 42 2/18 3 PALIT 3 Soe lear} 1 be 782 \286 | 76 | 69 | 72 |279 | 98 | 14] 8|21|13] 42 Taste LIII.—Location of egg and feeding punctures of the plum curculio, Myrtle, Ga., 1906. KIEFFER PEAR. F F Location of egg punc- Location of feeding RO SG tures on fruit. g | punctures on fruit. rf gle 2 Salles Dates of examinations. 5 SiIBls|3 Ae ce 3 5 Pe Url = Saleen ® From— | § | Sel celery oj;+] a 2 Ay SAE Sait baie ey [ees begs ai/s]5 g Sol ecole erate a mest | ee see es ee 5 Bo | ea | S| seul |e. | onh ole | Sans Z Al+/M;/Olsa|/alel/a/mlo;<|a it, Oia Ser ee 200 | Tree. ..... 16 CASA Gels | eleee| | 5)i\p 23 : Leagan ot eee are ee eee 160 | Ground 3 S| i ace et en ees 2)| 2 (er 1 US ae OSA Ree CaaS Sopemete 100) |)Drees =.= 20 aea|Pdoa|) or]. 4] Lo! | br 2 Ub = 6088) Seohe roe aes eee 100 | Ground 7 secu) fal ee ol eee 8| 2 Wi Bane oc Ate Oates ae raisin inte) > ans’ = 50" iree- ee a 40 Seer eet each e) |= SIN sce] | Se Go aR Oe eee, See 50 | Ground 9 Seer |e Hl wal A ec LLAST 5 IE See 50" |) "Tree. 23 . 260i isal to ibe Golcs [8.12 oe eS Ie on: bance Re eee ee nea oeees 50 | Ground 22 1 || 2 | oer 12 a | 5| 3 3 hes aR eae ee eee DO) ||hireet esses 16 74) tes ee aS OR (4 Pe a a JN Oe S10) eee seer 159} 3] 9| 88 | 24] 35)77) 6| 2/45/11] 18 104 THE PLUM CURCULIO. TasLe LIII.—Location of egg and feeding punctures of the plum curculio, Myrtle, Ga., 1906—Continued. APPLE. : les Location of egg punc- Location of feeding Fruits examined. tures on fruit. % | punctures on fruit. 5 . . Sond . 2 = : = s : Dates of examinations. 5 SaiE/3|38 BIE\S A, oO on i) = i— oo] Ss = © From— | § ae ae C= 2 2 Peele =z si (SlZiSiSisisis¢isiaia 3 walala|/s§lale|/sSilala|s|]ala Zi Rle|masolsaial[el/ Te ee eee ie eis ek i art oO . SRS) ~~ | O8eg a ® 5 ; jz =) =| } as VUSIN | Sot ED tt HN ND OD st 4 019 09 © 09 19 09 09 09 OID NN OD HOO SH SH LO ID ae Noch ear ar olry or) to THI HON tH IDA AAO mS OD YS “Ht 2 Dm oa t < = 4 rate (dls Z ES A Se Te = ‘=> ' ' . Py Car LLL Se ee . ° ' a . P 8 8 Ba| . & A MONA N OH PRA NHN NOHO RRMA Gf hol Gc yo fh ns ees | = | Oh et wee Cat) IO Many 1 Q 7) =| % Ved i i ° 5 A gabaamaretrte ott lat ty ‘ : , as ik Aiea Te FG = a Oo e : : : ‘ iia vie ae pathy fon SON teh Roe ae a0 ; ; : ; ; a, 5 ; ; ; ; eS aS 2 | <3) qU3IN | 1D NAMANMANRAMONHAN (HMA HAARAN ONAN Od te Re IN td HOt te Ballets atime Ge ceapanath 8 S & Qo # q . 1 ‘ ‘ ‘ Tse eae ae a0 os = ee FID MIDANNMAH | OMAHA AN AHA HHH MINN HINO NMIDING IHHAN 'oo ito) teste: Os a ee Cysek cede Olea os Ad ed aH ON -|ag0 8 ; : cies ey : Sere kate IES er Ge) o ? 5 TCE 7 Cage Ca Ai ni ae yi ae A gic IN DODANE PHN ATHAANDNO (RAMANA OH HMMM IONAN OOOOH INO EHONININM TO em tet tL 2 3 ie gas qU3IN ; : ? es : Lah, Xo eC erie Maman ted seat wm ~ , Fi ’ oe Cav . “In = S & ; : Ne ETNA EIN Gao Soom Senco aan maine ene ee See re an een a a eC oe weap a ry oS a @ ed . . . ' ' ' . ' ‘ My sy e) or for] ' i : ie Res eer Re ek epee rte. Naga Meee ene cal s3B 1m Bo 5 Se ; = 2) ‘QUIN | AA ONO ABAARAN ES teiog eA tts | ODA ODA HANAN te IO OD NOON tr ts birt tet | is} : ‘elt ae. Ge * Sa ' ‘ ; 5 : +. ate (eer nie Oa 7 Sl [ed = Cas “fk AD ARNAANAHAD (MAOH OHIO TENOPRHAHHOMDINNW CHOWORAO HN INA i tt ett 1 1D To ee i] Q ae oe CD 2 ed , = = ' ' Fo yy . - ir (oun = as a |oae |__ z ; : : : eel ba) —_— . ' . . . . . . . . an a) N $25 . DO § CMOMNAN CA HAAN SMH (MONOCMAAMNMAGDAMDA WOOHOO OMRMRO ters (OMIM N Fst HOMO mo + ‘Om = . wo i =< 3:3 S Las | WO3IN 3 : S ; rh : han re -: al > a iL | £ “seq | OH HOONA MOAN MOANING HODEDOT HANH OD HOD te IOS MN ek ten oh |= fon] aa & va ; : ieee MaMa She eERO NMP ar tee eee MeL sel ys aeseteiave ov <0, i ‘ Pmt cal (ee (2) 2°85 oo 7 : 7 : ¥ Sat aa ra ; <3 OL EO 7 ra SS 3) “4U3IN | SSRLCYO Ip SHI Cyo iO IAAI GN TTC ered rt ACN riled NCO Cyt DTM gee ede OC tl CMTE ra NN) Ue eC) Het COCN aw ' |3 Oo : ; iF : EAL Mais ce, caren 1-Linetey Oy i nD stu to ; ; , ; ; PIE = 2 & Bag “keq | DD DWI AINAD OOD AID (HO MMAHEONNINMOMHINOOO I HNRHONMEEOD HORAN ORA RAN ta IRE tt tt ts |g ss) ‘S S — see ee ee we ee a i ES i ete A ~ o . ’ , ie : . ry = S z S55 “USI DAN ONAMMONHAMHRHAMMOOKRANRMAM 1MOTANMINE MODOHHOINDOD 1 1OHINOS +) ORO HANNO: 1NINIOSH + | - = Zz, oa JUSIN bol = = ' : ‘ wes ‘ 7 ‘| 8 & iat - ‘ ‘ 1S SI = = 5 ee “seq | OUI HOD HN ODD OD HOD HOD OD OND LD HDD OH OD ONO TOD NOD HH OD [5 2 é, vee. ae ; 4 ; } ea : } de rag ce 0) S) Au ep = ; ; ; ; o & Q “qq3IN | DAH ADHD HINDMAN HOO HHOAMNOOHMHN ot NO INA ANA Oo IH HHON Pop aen NOD ona ts |Z l ah ad peer es a othe te A Spier .fearince Ti UMP taepuRnIec: GRA steca: tat Go-Ue CA Sci a ed Ce creer mM cr: rN yun, i A pay eVeudey, Ty ‘ > 5 3 Ricerca Paria Gen tal tetas’ Ustan ScacahetelmCoublinicren NePilenatite tee oe ts eae hasan ais heehee on ermine amie em ade sc denuke. OG o CG atmec. ee =] “a ae er ee eee eee ee ty cy ietevp atta pile ciate phate lel tacera aye enn Oat MRO Corl. RRn ecg Coma | og Ae ee owe Uy he Cy asec och SOL ey rhb) Cee enc ste ier CTR ea UO MOM SV) Cee aM Oe Oo ern KT CU ae” er eter. ol ‘ Phe cle Chie tg 6 Aeris eae ab deputy are te Saath Get tH BY. eG N Hace EEC eGR aor pean bata: Be ee or Oe oat pee oh Sar a ad Bi bc MESS RE a a a : = — SS ANKGSABSKKSSHASHAH SOR HOSHOeO MINSK KOSH AAEM SM AS SHAS ICR aS ems Sr aS ABSONS I os NOD RSNA NOINNNNANAN OD OD SS NANAIOINAANAN mo ip & ra > é co Bb < = a o | S B 2) jn | 5 5 110 THE PLUM CURCULIO. It will be noted that in the case of each of the five pairs, the num- ber of eggs deposited during the day is greater than the number laid at night. Of the total of eggs laid (1,291), 654 were laid from 9 a. m. to 9 p. m., while 637 were deposited during the balance of the 24 hours, a difference, however, of only 17. a eee July 1-30, 1910........ | Vee Oe as PH | eg pg 15 Ti cl es eR ae Ce Twit TEI A 71} 4) 3) 2) 5| 3) 1) 2). v1 es Tet 2 hae the ee ene epieastos ees es Cok: 415] 8| 9| 7| 8 5 3 ‘ 1)..| 3) 3|..|11]12.26 | | Youngstown, N. Y.......- ee June 21-24, 1905.-..-.- 10} 1) 1)..)..)--]--]--|- As 1 aie M@prthi Kast, Pa......-.-....:-.--.- June 13-14) 1906... -... a7) airals ds ae PAP S| Be = Ea Washinton, D.C. s.-----<22---.2- May 10-June 10, 1905... tae J CaF ed EVERIO) GAN ssn a src ceases otinae May 7-16, 1906........ PAS MLE SES eal oats al IOHMEIAS., MICH eas. sac cass haee June 24-July 6, 1910... 98] 1) 1) 1) 3)19) 9} 7| 4:11 17| 8| 1| 7} 2 4 einen totaal os brant amen set: oe ene 597/14 14 8 12)23)1211 5142012, 1181430 112 THE PLUM CURCULIO. Taste LVIII.—Showing time required for transformations of the plum curculio from egg to adult. Individual records—Continued. Beatles emerging in specified Aver- FeSon) «| aurrehs ays from oviposition. Total age Localities. Dates of ovinostalevut: life | length s uals cycle. | of life 66) 67 68/69) 70 71 72 73)74)\75 76 77\78 cycle. Days. | Days Barnesville Gass 2 -neeee eee Apr. 8-14, 1910...- 2 1} 1) 5,984 67.23 DOs ee ee Nee Sere eee May 9-26, 1910.... é 2,327 45. 64 DORs: cy sie Ow eae June 16-30, 1910... : 1,204, 44.59 DO. Se ane ene eee July 1-39, 1910. ... -| 7,979) 45.06 DOs 2cee Hee tees Aug. 7-17, 1910...-. = 3,511 49. 53 Mortal! copaice, trees As ee ome 2 1 1) 20,995, 50.35 oun oStowil Ne sere eae June 21-24, 1905... 0 | Bel esl Bes eel kee Pelee sels a)edlsetiac 498, 49.80 North Bast eaesesoee-eecses June 13-14, 1906. -. P74 scl osl cle Sloe eclaal ee lealeeleaiee 832 43. 06 WrashinatonyD) Cheeses see May 10-June 10,1905 eo es Pee) ( ( al PL Une oe eal | 1,220) 36.97 sMiymiley Gace ase oe ceva May 7-16, 1906. ..-. DA es alice cll cil eves eset ee eee tore ete 1, 086 45. 25 Doulas Michsss ses. =e eos June 24-July 6,1910 co} et UV et ee Pe eel elise Pole yf iese aye ais Grand)totallsse.e ete eee hee ene eeeee 597/17) 9) 8 ales 1} 2|..]..|..].-] 1) 1} 30,359) 49.85 The several averages of time for complete transformations in the individual records show a range of from 36.97 to 67.23 days, the former from the insectary records of 1905 at Washington and the latter from Barnesville, Ga., in 1910. There is here a difference of 30.26 days, but it should be borne in mind that the insectary records show a much shorter life-cycle period than normal, by reason of the high temperature under which the insects were reared. The average of all localities is 49.85 days, differing by only a fraction of a day from the average of 50.27 days already shown in Table LVILI. SEASONAL HISTORY. TIME OF APPEARANCE OF BEETLES IN SPRING. The curculio is roused from hibernation in spring by about the same temperature conditions required to bring into blossom the various deciduous fruits upon which it subsists. It is a matter of importance, however, to know just when the beetles first appear in orchards with reference to the condition of the trees; as whether before blossoming, during this period, or after the fruit has set. This question has a bearing on the time of making spray applications and of beginning other remedial work, as jarring. Little exact information on this point is to be found in literature. Dr. Tilton (loc. cit., p. 116), writing in 1804, remarks that— Early in the spring, about the time when the fruit trees are in blossom, the cur- culiones ascend in swarms from the earth, crawl up the trees, and as the several fruits advance they puncture the rind or skin with their pointed rostra, and deposit their embryos in the wounds thus inflicted. Mr. William Bartram, in a paper read in 1789, expressed the belief that the insects appeared when the fruit was half grown or younger, TIME OF APPEARANCE OF BEETLES IN SPRING. fi and Dr. Harris (loc. cit., p- 67) remarks that they begin to sting plums as soon as the fruit is set. Dr. Fitch (Essay, p. 16), writing in 1860, states that the insects make their appearance on plum trees when the young fruit is about one-third or one-half grown. The question was well investigated by Dr. Trimble (loc. cit., p. 72) in New Jersey in 1864, and frequent jarrings were made beginning May 12, at which time quince trees were in full bloom and green gage plums were just forming. Three beetles were caught from plum on May 13, 1 on May 18, and 10 on May 20 on knots of cherry and plum. Curculio punctures were in evidence on pears and cherries on May 18 and on plum on May 19. Walsh (Prac. Ent., vol. 2, p. 75) states that the female curculio makes her appearance early in the season, and as soon as the young plums are a little larger than a hazelnut. According to Dr. Riley (loc. cit., p. 53) the beetles in central Missouri begin to enter orchards during the first days of May, and commence to penetrate the fruit about the middle of the same month, varying with the season, peaches at this time being about the size of a small marble. Riley (Amer. Ent., vol. 2, p. 131) further states that the curculio commences to puncture peaches when they are the size of small marbles or hazelnuts, though she may be found in the trees as soon as they are in blossom. This point is not touched upon in the excellent account of this insect by Riley and Howard in the Annual Report of the Commis- sioner of Agriculture for 1888, though in the colored plate accompany- ing the article the weevils are shown on a plum twig, the buds of which are not yet expanded. Lintner (11th N. Y. Rept., p. 122), writing in 1895, says that the plum curculio enters upon bia scene at least two weeks before its first crescentic cuts are made in the fruit. More exact data are presented by Prof. Crandall (loc. cit., p. 495) in his studies of the curculio in Illinois, in 1903 and in 1904. Thus, during the spring of 1903 apple trees were carefully searched at fre- quent intervals, but no beetles were found until May 10, when they were abundant, appearing to come all at once. Apple pads were opening by April 16, the trees were in full bloom April 22, and the petals had practically all fallen by May 4. The beetles, therefore, were not in evidence on the trees until a week after the blossoming period, coming suddenly in large numbers. In the spring of 1904, systematic jarring of two trees was begun April 28. One beetle was taken from tree No. 1 on May 4, 1 on May 5, 5 on May 7, and subse- quently, a total of 15 by May 19. On tree No. 2 the first beetle was taken on May 17, and 1 the day following. On other trees beetles were taken May 7, and a few subsequently ‘during the month. Apple 17262°—Bull, 103—12——8 114 THE PLUM CURCULIO. buds in 1904 were expending about May 3, trees were in full bloom May 10, and the blossoms had fallen by May 15. As compared with the condition of the trees, in 1904 the beetles were in evidence about two weeks earlier than in 1903. Some data have been obtained on this point by the Bureau of Entomology. In 1905 records were made by Mr. Johnson, at Youngstown, N. Y., (see Table LIX) and though jarrings were a little late, the results are of interest as showing the occurrence of insects with reference to the condition of the trees. TasLE LIX.—Time of appearance of plum curculio on trees in spring. Jarring records, Youngstown, N. Y., 1905. Japan plum. sere Peach. Pear. eae : 2 : Condition of trees. ‘ur- ur- ur- Cur- Trees. culios. Trees. culios. Trees. culios. Trees. culios. 50 1 25 2 755 Sepa seacemen) eae nok 25 9 50 6 25 ya lesa Bee eee ene . 25 BAN is Saeseclh on doscs 25 PH eae se ease Japan and Domestica plums in full bloom. GEC 25 1 25 4 25 1 PVE Aaa te Lee 50 39 50 23 25 1S rset yer ere | Peach in full bloom. ik eee 25 9 25 12 205i enlace ese eee ears Pears in full bloom. Deena 25 8 25 7 25 1 25 2 | Plum blossoms fallen. p) ae 25 6 25 2 PAS Penner 25 1 - 2 sae 15 30 15 11 15 Alin te oee| a cleatoes BORN. 3 | 25 26 25 15 25 Psi Laeger oe Peach and pear blossoms | fallen. June: 1-!-_: 25 B24) ose Sanuliaemancee 25 Pale eee) oes ake 7 ae RES eee ence tal ee rend lama ce eee | Ries Sn elles ska | First egg punctures seen | onapple and plum. Total |........ | 195"|20 cs 82 cee | istics aoe 3 | Also, similar data were secured by Mr. Johnson at North East, Pa.. in 1906, as shown in Table LX. TaBLeE LX.—Time of appearance of plum curculio on trees in spring. Jarring records, North East, Pa., 1906. : Domestica Sweet cherry. | Sour cherry. Apple. plum. a a a é Condition of trees. ur- - ur- ur- Trees. | cutios. | TT€€S: | culios. | TTS: | eulios. | TT*S- | culios prs s0 sees |e Joel ees soeleeecas es aceaace ig eee Seee ee ec Cbd PESSaree Cluster buds of apple just opening. May 62.22. 50: eh ectect 50 8) Sn scitnss | Soceee oe] eecacees | seemenee eee Di) eeeaiete| Satara tereisestecate 25 | Beaceskes Hesasas: Re 4 Rear! Cae see Pacem bnemcse 50 Wo osm ab cee | teemenios Sweet cherry and plum trees in full bloom. 14s 25) |Soceeae aooeeemaloee cee e 50 (hl BAgene or oocusnce LGseene 7A Se cinta Naoe ane 50 25 25 1 Sse QB S= occieterele 25 1 fl esse e eamnes eseereee| Gecuan sc Sour cherry in full bloom. BOE e Er 25 1 25 7 25 25) Pace eeiesposieninerte DR Bees se) Cee 25 7 | awesnictcrel| ce selene Eocene | eee First egg punctures on plums, pears, apples, and cherries seen May 24. Total'|.....-- ie Boi |Baese rr Neate ee 1 TIME OF APPEARANCE OF BEETLES IN SPRING. 115 The same year (1906) Messrs. Girault and Rosenfeld investigated this point in Georgia. In addition to the trees jarred, as shown in Table LXI, various trees in the woods, as Crategus, wild plum, ete., were also jarred, but without results. Taste LXI.—Time of appearance of plum curculio on trees in spring. Jarring records, Myrtle, Ga., 1906. Wild plums ParEniCketist Peach. |Japan plum. Pear. Apple. Dates trees g “s # a a Condition of trees. jarred. f2) 2 2 2 £ Ser es aeee hee ie S| ee le ge 5 2 | iS 5 iS 5 zB | z 5 a oO | aaa pelea 336 20 1 ee 336 483 Pe wl das' 336 i a Petals fallen from Elberta peaches; first egg punctures in plums. eee 336 ,07 Seapets ce 336 563 | Petals fallen from Carmen peaches. Ly 9 eee 336 534 Vieenee 336 427 | Peaches bursting through calyces. (Nee ae 336 243 Seren sis 336 166 Taste LXIV.—Time of appearance of beetles on trees in spring. Jarring records, North East, Pa., 1910. Dates trees jarred Trees. |Curculios. Condition of trees. Apr. 75 3 | Less than 5 per cent of peach blossoms open. (hay |e ae ene About 75 per cent of peach blossoms open. Peaches 90 per cent in full bloom. Peaches shedding some petals. May 2 (0) | stseetiese Nearly all petals fallen from peaches. (GN Sasa All petals fallen from peaches. 75 7 CD 33 ae 75 1 oul eee aes 75 5 75 19 | Teaches beginning to burst calyces. 75 22 | A few calyces falling. 75 22 | Many calyees falling. Taste LXV.—Time of appearance of beetles in spring. Jarring records, Douglas, Mich., 1910. Dates trees . ae jarred. Trees. |Curculios. Condition of trees. Mays abt. s28 red ee es ee Apr. 25, Elberta peaches, pears, and sweet cherries shedding petals. (ie ee Sa Olea xt 2 11 Se eee =-d0m 3 1 Vee ate E2d0las2s 2 ee ae eae 3 | Apr. 30, sour cherries in blossom; also apples. cts saree 3 ido} 15 ee ee ee dOnee. 115 7 eee : oe ane 58 | May 3, Bartlett pears in blossom; also some peaches. 772 ae SeeAOl sc 67 PUNE Les... a ae shes 57 | May 4, Baldwin apples in full bloom. eee 2-222) —2 GO). 132 74 (apne SE ail lap nore 82 | May 10, Spitzenberg apples in full bloom. See eee eae dort 97 Ee eee Bee do.. 94 1D ete ctas' css] oe = do... 315 een ae dor. 350 7) OEE See pe do.. 114 EN es eee do .. 103 From the foregoing data it appears that the curculios usually first appear on the trees each season at nearly the same time relative to the advancement of fruit trees, namely, during or a little before the 118 THE PLUM CURCULIO. blooming period of apples or shortly after the petais of peaches, pears, and plums have fallen. In some seasons, however, the curculios may appear as early as the blooming period of the plum or be retarded until after apples have shed the petals. Thus it appears that the beetles are affected by temperature to a different degree than are the plants on which they live. Probably the curculios are more sensi- tive to short periods of warmth and less so to longer periods at a somewhat lower temperature. RELATION OF TEMPERATURE TO APPEARANCE OF BEETLES. A comparison of the numbers of beetles caught in jarrings with the average daily mean temperature immediately preceding each jarring furnishes information on the temperature necessary to bring the beetles out of hibernation. Such data are available from Youngs- town, N. Y., for 1905; Siloam Springs, Ark., for 1908; and from Barnesville, Ga., North East, Pa., and Douglas, Mich., for 1910. These are given in Table LXVI. TaBLeE LXVI.—Jarring records showing relation of temperature to appearance of beetles of the plum curculio from hibernation. Barnesville, Ga. Siloam Springs, Ark.| North East, Pa. Douglas, Mich. | Youngstown, lV. Y. AQ Ae ae =) ag 35 a5 35 38 Be ga ga a 82 5a Lane) 3s aca hes [Bea I as Pein! | os 2a : Bea) = Bea) s Beal s Beas BEu) Ss Dates. ([28| # | Dates. [SEE] F | Daies. PES] P| Dates. [SES] } | Dates. (SEs) & SEE =| SSh/ 3 ofe a SSet| 3 OSE] 38 oodg| © oo 8| © oos| 2 oom] 2 oH oO was} ea-| 2 Lees] 1 o—| a wes] n Ses 2 S gis| Say! & Se] & Sxy| & n ~— n - ni. . Lilw~ nin hes 225) 3 $28) 9 FSS] 3 P25) 2 < ea) < ea < ea) < ea} 4 ea} 1910. | °F 1908. Sei 1910. °F. 1910. | “FF 1905. | °F Mar. 10 63 9 | Mar. 28 69 | 6} Apr. 15 43 | 3 | May 7 44) 2] Mayll 54 3 14 55 9 30 ASN ee 20 52 10 52] 3 12 50 | 17 16 47 1 31 o2 | 2 22 39 13 46] 2 15 57 | 36 18 50 5| Apr. 2 61 26 45 16 45] 3 16 59 6 21 57 2 4 43 1 28 45 |_... 19 54 | 15 17 59 | 63 23 59 | 483 6 52 1| May 2 DOU ee 24 60 }115 19 56} 21 25 67 | 840 8 64 | 42 4 53 26 52 | 58 22 50 18 28 69 /1,071 11 56 | 17 6 41 28 48 | 67 24 50 9 30 71 563 13 53. | 13 9 49 7 | June 1 51 | 57 27 59 | 45 Apr. 1 7 534 14 61 8 11 51 3 44 | 74 30 56 | 43 4 71 | 427 15 62 | 44 13 40} 1 6 53 | 82 | June 1 52 | 34 6 71 | 243 17 66 | 64 16 40 9 50 | 97 8 65 166 20 64 1146 19 62 5 12 59 | 94 ll 62] 169 2 66 |169 21 60 | 19 15 63 |315 13 68 95 24 65 } 75 23 66 | 22 18 70 |350 15 64 69 27 60 | 10 26 61 | 22 21 69 114 18 64 72 30 46 | 16 28 50] 1 24 75 |103 20 56 12 | May 2 51 | 41 30 60 | 19 27 72 | 47 22 54 53 5 64]13]June 2 46] 4 30 68 }145 25 59 15 9 54 | 28 4 50 | 13 | July 4 74 {105 27 46 16 12 62 | 57 6 50] 6 29 55 90 14 67 | 15 8 51 4 May 2 70} 125 21 72 | 91 10 56 | 31 4 73 82 25 71 |193 13 57 | 13 6 67 52 27 74 {198 15 64 | 19 9 66 29 30 70 | 87 16 67 | 37 ll 65} 101 18 66 | 19 13 73 31 20 67 | 28 22 70 | 26 25 69 | 21 27 67 | 19 29 68 | 18 . TEMPERATURE AND APPEARANCE OF BEETLES. 119 The effect of temperature in these records is obscured to a con- siderable extent by other conditions that affect the number of beetles caught by jarring, as winds, rains, proximity to hibernating grounds, and number of beetles previously caught. But the data seem to show that some beetles will become active at a mean temperature of 55 to 60° extending over three or four consecutive days, and that a mean temperature above 60° for several successive days will bring out the beetles en masse. After the beetles have once come out of winter quarters they may be jarred from the trees following periods with a mean temperature much below the degree required to bring them into activity, though such periods of cold weather greatly reduce the numbers caught. In Table LXVII is given a summary of the data in Table LXVI, showing the number of beetles caught at different temperatures for all five localities. It will be seen from this table that beetles have been jarred in considerable numbers following days with an average mean tem- perature below 55° and even below 50°. But by a study of Table LXVI it would seem that these beetles had been brought out by earlier spells of warmer weather and were already on the trees when the temperature dropped immediately preceding the jarrings. Prob- ably a mean temperature of between 55 and 60° is required to cause the beetles to leave their hibernating quarters. Taste LXVII.—Number of beetles of the plum curculio jarred at different temperatures, . all localities combined. Svereee ores ay, Average ZIM Average mean mean . 1 le: . Beetles I emp Jarrings. pen j ame tempera- | Jarrings. Cau ant, ee F nee . es ring _ tures ring since last 3 since last i jarring. jarring. ng? ig ett 39 | Se Re Ie ei aed 57 3 69 23 40 2 1 4 TROP eee cice| AAS Gaeee] MOREE cere 41 ele seen cnc |aee ceeee ae 59 6 706 118 PE eres ee | ein niern oct sea 60 4 351 88 43 2 4 2 61 2 22 11 44 2 76 38 62 3 221 7 45 3 3 1 63 2 334 167 46 4 38 9 64 6 361 60 47 1 1 1 65 3 342 114 48 2 68 34 66 5 301 60 49 | 1 7 Te 67 6 991 165 50 9 166 18 68 3 258 86 51 4 102 25 69 4 1,212 303 52 6 98 16 70 5 1,122 224 53 3 95 32 71 4 1, 426 356 54 4 99 25 72 2 138 69 55 2 99 49 7 2 113 56 56 5 124 25 74 2 303 151 75 1 103 103 | 120 THE PLUM CURCULIO. OCCURRENCE OF BEETLES IN ORCHARDS. The relative abundance during the season and the distribution of the beetles in orchards are shown to a certain extent by jarring records. Several such records have been obtained, beginning the work of jarring quite early in the spring and continuing at short intervals until the gathering of the fruit crop, or later. The early portions of the following records, with additional ones, have been given in connection with the consideration of activity of beetles in spring. Table LXVIII gives the results of jarring 950 Elberta peach trees, at Siloam Springs, Ark., for the period from March 28 to June 27, 1908. This block of trees was used to determine the value of jarring in protecting the fruit from injury, as referred to on page 174. TasLe LXVIII.—Jarring record for the plum curculio on peach, Siloam Springs, Ark., 1908. Dates of Beetles Dates of Beetles jarring. caught. jarring. caught. \ || Mar. 28....- 6 || May 2.....| 41 SOS. INS A eee Bie ek 13 af eee 2 Gi Sei 23 Ny] 0) i ae a) |e ees Sor IPE EY ee 1 | F Seer 15 62622. 1 | eee 91 faxes 42 Zoe 193 1G ee 17 eee 20 AB. 5-2 13) oi) 7 eee | 198 Lt eee 8 eee 87 15 222 44 Juineses-< 76 ates 64 5 112 Diss 146 th eee 1 Deere 169 15 es 96 24 75 by cere 107 Qh eee. 10 19. 84 8 Beas 16 22). 118 Wee sa3 128 Total -| 2, 209 The spring, on the whole, was late, there being much cool and rainy weather. The beetles were notably scarce, only 2,209 insects being captured during the period of jarring, an average of about 2.3 beetles per tree. Considerable variation in the number captured on successive dates of jarring is to be noted. Thus, on May 25, 193 beetles were taken, and the following day only 20. The record indicates the erratic behavior of the beetles due, it is believed, to weather conditions, but shows that by April 8, beetles were out in numbers, the maximum emergence occurring during late May and during June, with a smaller maximum about the third week in April. In Table LXIX are shown results from jarring a block of 75 peach trees at North East, Pa., during 1910. The trees were in sod and had never received treatment for the curculio. They were jarred every other day, unless weather conditions prevented, beginning April 15 and ceasing September 2. The three specimens captured April 15 BEETLES IN ORCHARDS. 121 indicate a very early movement of the beetles for that locality, though no more were taken until May 9, more than three weeks later. Activity of the insects did not properly begin until May 21, after which date, with the exceptions shown, they proved to be fairly uniform in numbers up to July 2; after the latter date few were captured. A total of 381 individuals was taken during the period, an average of 5 and a small fraction per tree. Taste LXIX.—VJarring record of the plum curculio on peach, North East, Pa., 1910. Number ne ae Number r A s Dates ofjarring. | of beetles bs ae endl || Dates of jarring. of beetles W oe Z poaee caught. a caught. ions. PDE LOL Sek os ois =e 3 | Cloudy. Une: 20 Sees ees 23 | Clear. 7 Bee See Sere ae Do. 7 POD ER eT 26 Do. 27 te a A Seo ee aa Fair. VAT Ae sane toes 21 Do. 2 Racin Se eee ee Cloudy. Dis cece 19 | Cloudy. DE eras sfeice.s = Seem Fair. DOME ere tene oe 18 | Clear. CL UDG D2 SR Seni Pine Foggy. Stalls 82 eee ccene- 12 Do. ole SARC OBSA ocean Gee Clear. Biyeetaataia/aeoe| Shorea as as Do. Gee ccte ce 2ntls sstlasce ed Do. Ube acecneetoe 3 | Cloudy. Lh Raat ea 7 | Cloudy. (ier 8, Sot hey ool a ee Clear. Dee nema: inst =| om- cote o Do. 1 eee 1 Partly cloudy. UB crete te re eit 1 | Clear. 1B eee easee [eee er eek Do. AG) ES oe Se) ee ae Do. 1G Bet octane leaeweeeece | Clear. IOe Saas vossee- 5 Do. 1h Ses ae SSeGperteet Do. DIRE RS 19 | Partly cloudy. up| Se a SS Sell ep ee | Partly cloudy. 7 ie AS See 22 Do. PA ek ere oe Vanes ee na Do. 2.) eee 22 | Clear. DD eine aoe Sede e eae Clear. Ue as eee Ae 1 Do. PATER Ee ey ect ces ees Do. Sime eee ara ae 19 | Cloudy. Gin NS Ee Ae oe Rae eee Partly cloudy. iy OR eee 4 ih eee eee es 2 | Clear. BE ee Sees sis cise 13 | Fair. LG eee Ae ee 25 Do. a ee ae 6 | Partly cloudy. QR TENS So ae: 2) Foggy. Be Rassias siete 4 | Clear. Pa Tete 1 | Partly cloudy. 1 ge are ae ae 31 | Partly cloudy. BORE eee ce aacee 1 Do. {Be See 13 Do. SYS) 05307 es rs ee | CN ee Do. bee toes crass 19 | Clear. — Ue eee 37 | Partly cloudy. Motale-s.. a. 381 ihe oesebaccaae 19 | Clear. | | In the jarring records obtained during 1910, at Douglas, Mich., a block of 70 peach trees was used, and the number taken on each row at each jarring was separately recorded. Row No. 1 was adjacent and parallel to a piece of woodland, the influence of which is evident by the larger number of insects taken early in the season from the first two or three rows. After about June 9 the beetles were uni- formly disseminated over the whole block. From May 4 to 10, a total of 5 beetles was secured and from May 13 to 19, a total of 20. From the last date they put in an appearance rapidly, showing for the period from May 24 to 28 a total of 240. The beetles were in maximum abundance during June, which month yielded 1,468, or 59 per cent of the total for the season. The insects, nevertheless, were quite generally present all through July and August. None was taken after August 31, though jarrings continued until Septem- ber 19. (See Table LXX.) 122 THE PLUM CURCULIO. Taste LXX.—Jarring record for the plum curculio on peach, Douglas, Mich., 1910. Curculios caught Fy rows. Dates of jarring. a Total. Row 1.| Raw 2. | Row 3. | Row 4.) Row 5. | Row 6. May 4......-..-------- 2-2-2 eee eee eee ee eee [eee eee elon ee ee ee |e ee ee |e ee ee [ee eee ee eee lee eee eee Teee ee Soaswn tod Laat Bec eee ee noeeers 1 | See ee ee 2 1 (1 ee ee ee Sr i oan | eS eR 1 1 1 Eee EE ON Pears <> oe 3 Woe Le or oe hewn conc eae ees te a es Reece are Sree be ie 1 2 ti CEE SS OS Scr ma SoC me OSE 1 SI Sees eee Ts p34 ese 3 i eS eee eae He ere nn San = 5 6 1 eer ese 2 eis oe 15 OA ons. 2 aethe be Se eee eee 33 39 19 8 4 12 115 DG Sa ee eee Se woh Se eater cee cee eases 19 22 7 6 2 2 58 DR ea SU eee se erence ee a Meveio aes 21 26 8 4 5 3 67 June 1......-.--------+- ++ 20222 2eee seers eee 12 21 9 1 1 3 47 aS cee cect ees een kr Sergey oh Sree 25 20 16 5 2 |- 6 74 Geo h eee aes Oe ee ue eee en ee 22 18 ll 5 19 Zf 82 Qi eee ee pentane nears Rocio 3L 25 8 11 11 il 97 | oe en eS ees Be eS OCR Ee 18 20 16 15 12 13 94 1 eRe PO Se eee Ot ee EHR ae ac 84 87 37 31 51 25 315 1 Se Se each Rae ers cara mercies oo 67 84 87 51 40 20 350 ? Bee anaes a SHeASnsee sca Suet brs ar 22 27 19 18 15 13 114 DF ee at Sas On ee IE CEE Rn FOE a 19 21 25 23 9 6 103 OT oR eek 56 By eee sarees pees 10 1 11 3 10 2 47 QU es SLE Care. eae se eee eer 12 41 25 26 27 14 145 Ai «te eke nother nese aenonbeessaesee oess = 9 27 36 10 13 10 105 ( (Oe eS SC OM SEC RSet BES en 8 14 (el Eee ser 2 2 32 QUT oe aac ee Ae oe eee ee 7 5 4 Wineetoses 2 19 De es SS eee oe eh eee & 13 19 17 7 6 11 73 Tae eee i Sod se ee Sere 3 5 Pa) eee 5 33 14 91 1 ee ee ee CIO E Sessa ns 5 8 8 | 6 18) | Sess 45 DUS cee zen pee eo Bee oe eae 2 9 9 12 Boe 40 Da ae. esi ne Pee a ate ae oe se Oa 3 9 7 8 3 3 33. DY (RAE ARs 5 8 Sabre DEL ea RR AEE 1 9 5 6 7 1 29 SO ra ebee Se Sane Se ee oe ee eS 2 6 1 1 Ales teers 14 AUIS RARE GBA Nel 2 A/a Be ei) seein te 3 FU Re omar id See 1 13 No a A ee Ne hin el en clove ome asia 1 2 3 2S aoe 4 12 1 See tas” See eae cee e ae ectn a 6 8 16 3 6 if 46 13 SRR ek She, AR Nero ae oe ere 6 5 8 10 9 7 45 1 (ROEM, Py 5 elec, net Sree st reer et a 8 3 11 8 9 Bile 42 D0 ea ee ee he ier Ce eee 1 2 11 8 12 6 40 TAN eye PS Se RE Ba ee ee ree 3 14 14 7 9 6 53 DA fa gto ek UE oie Se eter OD SOS Se Gas 3 1g eee 3 4 2 13 Py De ae Paes ne cee RB poten Ree pal es 6 3 OF ae Sage 4 5 20 By far the most complete record, however, was obtained at Barnes- ville, Ga., during 1910 (see Table LX-XI). This work was accom- plished by Mr. E. W. Scott, though completed during the latter part CONTINUATION OF PEACH ORCHARD.— SPRAYED BY OWNER. g & 3} OTREESN Row 10- 3077S, , VARRED BLOCK aos re R& a Ce ae cee a iP le ore a ao a ys OF ee OO ca hier JC AHOLORCLOLO. Dc: We O.c Oo OC oe Onn, NS 6 15 48 ch ene is ge $ WHEAT FIELO Fic. 24.—Diagram of portion of peach orchard used in jarring experiments against the plum eurculio | Barnesville, Ga., 1910. (Original.) of the season by the junior author. Ten rows of Elberta peach trees were used, paralleling a piece of woods. Row No. 1 was separated from woods by only a wagon road. A total of 336 trees was jarred, all as indicated in the diagram (fig. 24). As shown in the figure, a terrace covered with grass and weeds bordered all of the rows on the BEETLES IN ORCHARDS. t23 east, and extended between rows Nos. 9 and 10. Excepting a check of 60 trees extending across the 10 rows on the west end, the trees surrounding the jarred block to the east and north were sprayed by the owner with arsenate of lead in self-boiled lime-sulphur wash. Taste LX XI.—VJarring record for the plum curculio on peach, Barnesville, Ga., 1910. Number of curculios caught, by rows. Dates of ; jarring. Total. Row 1.| Row 2.) Row 3.| Row 4. | Row 5.) Row 6. Row 7.) Row 8.| Row 9. Row 10. | Mar. 10 16 19 5 9 Be owas 1 3 5 15 20 406 483 460 840 550 1,071 206 563 Apr. 186 534 92 427 93 243 71 5 166 54 6 169 34 4 95 31 3 9 69 22 4 10 72 5 1 4 12 9 5 5 7 8 53 a 1 3 2 2 15 3 i 1 3 : 1 1 16 23 8 9 4 2 2 - 2 4 10 26 90 May 41 21 13 3 7 3 7 6 10 14 125 33 5 5 4 4 2 6 2 6 15 82 12 3 & 1 3 Sicesaee 2 10 13 52 7 5 1 | PRO aeSOe a aces Sacer 8 5 29 39 14 3 6 4 2 8 8 9 8 101 13 3 nl Reseeeee 1 1 DN ees 5 6 31 4 1 2h eee i eee 114 (dys Sees SS) | eee al ed 10 6 Re ee varayey Biles sciaees| tae 2 1 2 4 18 37 11 9 5 2 4 6 4 9 11 98 23 6 6 3 3 1 2 1 4 12 61 18 2 3 4 Sulseweenoe 1 2 4 4 41 15 10 3 3 2 3 1 2 4 6 49 17 10 2 4 3 2 3 2 8 7 58 June 1-....- 4 te ee 2 2 1a ae ee ee 2 3 15 Are Ss 10 1 1 10 Sa aocse 2 Oe be sea 6 5 29 f one 81 46 14 7 8 7 8 8 16 36 231 OF oe 55 14 17 lo 6 3 12 11 30 31 189 ibis 21 11 6 7 2 4 2 3) 3 63 panes 44 17 8 2 5 6 5 8 127 hOr- 36 25 3 7 4 4 3 4 131 eee 35 21 9 8 4 7 6 5 122 DE an 15 6 7 2 2 1 4 1 54 A el 8 2 3 1 2 2 34 yy ea 16 7 2 4 2 3 49 PH PSE 16 5 5 4 2 3 51 | ee 6 7 3 1 3 29 Walye 22... 4 3 2 1 1 17 Dei 13 3 2 2 24 eens 6 4 16 i Ree 4 3 23 Lee 13 5 34 2) aes 12 6 29 iT a 10 2 24 Dyan 1 3 8 Beast 5 2 10 ibe ae 1 1 6 15S eae 5 2 2 10 ‘Ct ae 3 2 1 7 ss. 13 4 3 2 28 2) ae 6 3 6 6 26 a) eae 2 3 1 1 a Bept., 22... 65 10 4 8 1 1 Bil NEES 2 25 119 Dees 36 13 8 3 1 2 Dh Ree eee 5 8 78 non. Se 7 1 Ply Bees 1 ee in| HS S= Sol RR 4 18 eat 32 3 A oe fe Soe 4 1 1 il 2 9 57 (0 See 14) 4 2 Noss aouse 1 Ae aS ee ee 1 it ee eee 2 24 124 THE PLUM CURCULIO. Tasite LXXI.—Jarring record for the plum curculio on peach, Barnesville, Ga., 1910—Continued. Number of curculios caught, by rows. rai ag a =a l Total. Row 1.| Row 2.| Row 3.| Row 4.| Row 5.| Row 6.| Row 7.) Row 8./| Row 9. Row 10. Sept. 23. .... 16 5 4 1 Pa Bes eceal peices ence Se 6 3 i 3 32 “2 (aps 3 3 1) epee ae) eens oe |e ere ae A oad (erat SN de c= 2 9 3{{ 2) pee es 8 1 Ecce osce|cncesibe]eas taceale settee eee eee 1 il Oche 4... .. 1 De (eee eee eee eet (eer eee | een Sen Neem es Pee ese LY Re See 4 (sae 3 Del. aa see ale aan canellcet aces) seeaeesleeaceceeles eeeeee lemme 1 5 i Paes 13 2 La ee Dilee 2 eS Oe een eee 1 2 21 [ts Pea) Nee eee ee anes IER) (etre egee ral ere el ee eel lems al a Slate ee ce VB. se pel) eco Seid cee |r ae Daca Ce es | Wena ele hace eee eee are ee este oe oe eee ee eee | ee ee ee | D2. oa rallsc ec now | sae msateell siete <5 lee east io el lm meter aa See ee mena Lee oc eee a | Total 3, 197 975 641 393 269 229 275 227 503 788 7,497 A study of this table shows the beetles to have first become active March 10, when 16 were taken on row No. 1. During the interim March 18 to 23 they began to appear in numbers, and were out in full force during the last week of March. Considering the results of jarrings from the individual rows, the influence of the woods as hibernation quarters is very plainly shown. Thus, up to March 23 rows Nos. 1 and 2 gave a total of 476 beetles, as against 61 from the other eight rows. By March 25, 15 days after emergence began, diffusion of the beetles had become quite general over the block, though the number taken from the first row on a given date was in most cases in excess of that taken from any other single row. For the season, row No. 1 yielded 3,197 beetles, 42.64 per cent of the whole number captured. From the first three rows adjacent to the woods a total of 4,813 individuals was taken during the season, or 64.19 per cent of the total. The influence of the grass-covered terrace between rows Nos. 9 and 10 is also evident, more insects being captured from each of these than from any one of the rows, Nos. 4 to 8. The beetles were in maximum abundance in the orchard from about March 25 to April 13, during which period 4,108 individuals were taken, or 54.79 per cent of the total. The appearance of the new generation of beetles is marked by a sudden increase in the jarrings for June 7 and several days subse- quently. Beginning with the third week in August an increase in the number of beetles taken is again noted, reaching its maximum about September 2. This may doubtless be attributed to the issuing of the beetles that developed from ripening fruit, the ripening period being approximately July 7-20. No beetles were captured in this orchard after October 11, though the jarrings were continued to October 26. But during late fall jarrings were made in other orchards, both sprayed and unsprayed, and also in woods adjoining peach orchards. After beetles ceased to appear on the regular jarred plats, many were taken in some of these NUMBER OF GENERATIONS ANNUALLY. 125 other places. On October 12, 3 beetles were jarred from 60 trees in a sprayed orchard, and 1 beetle from 50 oak and hickory trees in adjoining woods. On October 14, 133 beetles were jarred from 104 trees in a badly infested unsprayed orchard consisting of late varieties. The trees in this orchard had been bare of foliage for more than two weeks. On the same morning 144 beetles were jarred from 28 small oak trees in woods adjoining this orchard, showing a heavy migration to the woods. Thesame 104 peach trees were again jarred October 23. Only 30 beetles were taken, and only 7 beetles from 20 oak trees in the adjoining woods. On October 26 as many trees as possible were jarred in the woods adjacent to the regular jarred block of peach trees. Only 3 beetles were secured The last beetles of the season were jarred November 1, when 2 beetles were taken from the 104 trees in the unsprayed orchard previously mentioned. No beetles were secured in jarring 18 oak trees in the adjoining woods on the same date. This probably marks the complete entrance of the insect into hiber- nation. NUMBER OF GENERATIONS ANNUALLY. It has been accepted for years that there is but one generation of the curculio annually, though this was a much-disputed question among the earlier writers. Thus, the writer of an article in the National Gazette, which was reprinted in the American Farmer of November 15, 1830, states: ‘‘There are three generations of them during the five months of their existence above ground, and they are all very tenacious of life.’ Dr. Fitch ' believed the insect to be two-breoded each year, thesecond brood passing the winter in the larval condition under the bark of pear trees. He was led to this erroneous belief by the resemblance to the curculio crescent of a curved incision in the bark which he supposed was the egg puncture of the insect in question. The absence of fruit he thought necessitated this change in egg laying by this brood, and agreed with the earlier observations of Melsheimer that the curculio bred in the bark of peach trees. Dr. Trimble, as the result of observations, believed the curculio to be single-brooded, and this opinion was, in the main, accepted by subse- quent writers. Dr. Riley, however, in an anonymous communication under the signature of ‘‘V”’ in the Prairie Farmer for July, 1867, gave it as his conclusions that the insect was occasionally two-brooded. In his first Illinois report (1867), Walsh states his belief in the double- broodedness of the curculio, as follows: ‘‘I find there are two distinct broods of the plum curculio every year, the first of which comes out in the beetle state, in the latitude of Rock Island, IIl., from about July 19 to August 4, and the second from about August 23 to Septem- 13d Rept. Ins. N. Y., p. 351, 126 THE PLUM CURCULIO. ber 28.” He cites in detail rearing experiments to support his con- clusion, and cites Riley’s note in corroboration. Riley ' fully corroborates the conclusions of Dr. Trimble by rearing the curculio in a large cage over a tree, and states emphatically that the curculio is single- brooded, but ier goes on to say: But as there seem to be exceptions to all rules, so there are to this; yet the exceptions are only just about sufficient to prove the rule, for as far south as St. Louis not more than 1 per cent of the beetles lay any eggs at all until they have lived through one winter; or, in other words, where one female will pair and deposit a few eggs the same summer she was bred, ninety-nine will live on for nearly 10 months and not deposit till the following spring. In more northern latitudes I doubt if any exception to the rule will be found. During the present study of the curculio but little information on the tendency of the insect to produce a second brood under field conditions has been secured. Late records of larve in fruit could readily be accounted for as from eggs deposited by the longest-lived individuals of the overwintering beetles. During 1905, however, at Washington, D. C., a second brood of larvee was obtained, though no individuals reached the adult condi- tion. Infested peaches were received May 1 from Fort Valley, Ga., and confined over moist soil in a large covered glass jar kept in the insectary, where temperature conditions were abnormally high. By June 8 many adults were emerging from the soil, and on June 12 several apples were added. On July 13 eggs were found in four apples, and subsequently fertile eggs were laid on the 17th, 20th, 21st, 22d, and 24th of July, and by August 2 several larve had developed to full size, some remaining in the fruit and others entering the soil. Several larvee were separated for particular observation, but all of these died without transforming to the pupal stage, and no adults were secured from larve entering soil in the breeding jar. During the summer of 1910 a second generation was again reared under laboratory conditions, at Barnesville, Ga., this time a large number of individuals being reared to the adult stage. Adults of the first generation were reared out of doors from infested peaches gath- ered in an orchard, the beetles beginning to emerge June 6. On emerging, the beetles were put in large muslin-covered battery jars, 100 to 175 beetles to each jar, and kept in the laboratory. They were fed on peach foliage and fruit, but were often neglected, allowing the jars to become very humid and sometimes moldy. On July 11 several eggs were found in peaches taken from these jars. The beetles, 480 in number, were then supplied with ripe Elberta peaches from which all curculio eggs had been removed.. On examining this fruit two days later 113 eggs were found. Eggs were subsequently obtained in abundance, a typical record of eggs laid in fruit left in the jars overnight being shown in Table LXXII. 1 Third Missouri Rept., p. 11. BEETLES FROM EMERGENCE TO HIBERNATION. rey TaBLE LXXII.—Record of eggs laid by 864 new-generation beetles during one night, Barnesville, Ga., 1910. Beetles Dates of observation. in jars Dates beetles emerged from soil. Eggs laid. Night of July UZ katie CMe Se ane etan ae a See 6 D 113-| June 18- 11 156 | June 20- 16 185 | June 2 Bea atceini ee oats kines ee cieicieve cs 49 LOO! Rue: 26-29 ke ee See ee ea ears Sem e 20 LOM | une S0-Juilyr4 oes ses clio ta eee | 27 SO Ly: 516: cet ees SI ele Le | 13 Bd |: Ye = 0a ak ee ais arene eee Mike) 142 The beetles continued to oviposit freely until August 10. By this time peaches were scarce and no further observations were made until August 17, the beetles being fed on foliage alone during the intervening week. On August 17 some late seedling peaches, both green and ripe, were put in the jars and on the next day were exam- ined for eggs, only two being found. No more eggs could be obtained from these beetles or from beetles recently captured by jarring, although eggs were being laid in the field, where fruit was available, for a month longer. All eggs laid by the new-generation beetles appeared to be fertile and hatched in from three and one-half to four and one-half days unless injured by handling. One hundred and eighty-five individuals were reared through to the adult state under the same outdoor conditions used in the other rearings. The larve developed in ripe peaches, remaining in the fruit from 9 to 24 days. The life in the soil ranged from 18 to 45 days and the entire life cycle from 36 to 61 days. The adults from this material emerged from the soil August 22 to October 10. Adults from infested peaches collected in the field emerged as late as November 9, at which date there were yet many pup and even larve in the soil, though there is no evidence that these late individuals from the field were of the second generation. BEETLES FROM EMERGENCE TO HIBERNATION. In general, after emergence the adult insects pass the time in hiding and feeding, their activities growing less and less at the approach of cold weather, until finally they seek hibernation quarters for the winter, which, as shown, may be in orchards under trash, etc., on the ground, but especially in neighboring woods. More detailed information is needed upon the habits of the beetles after emergence, especially in the South and in other regions where the fruit crops are practically all gathered by midsummer or earlier. Under such conditions the weevils are at once largely deprived of fruit for food and doubtless subsist on foliage, buds, etc. In regions, as the Middle and Northern States, where a variety of later maturing 128 THE PLUM CURCULIO. fruits is grown, as apples, pears, late peaches, plums, etc., this exi- gency in the life of the insect does not occur. Nevertheless, the weevil in the Southern States is able to maintain itself in extended areas largely devoted to peach growing, as shown by the fact that the insect is here perhaps most abundant and destructive. The jarting records presented on page 120 show the beetles to be present in peach orchards until quite late in the season, but not in such numbers as during spring and early summer, indicating a con- siderable diffusion or early seeking of hibernation quarters. During September, 1905, Mr. Beattie, at Fort Valley, Ga., jarred 400 peach trees, securing 600 beetles, which he states were very active and were captured on the sheets with difficulty. Beetles kept in confinement from time of emergence until hiberna- tion have fed freely on fruit when present or on foliage when supplied with this alone. Their forced feeding on foliage, as in the South, suggests the possibility of destroying them in large numbers by thorough spraying with arsenicals after the fruit has been har- vested, insuring their material reduction another season. In the more northern States the beetles feed freely on various fruits but are especially destructive to the apple. The so-called fall feeding puncture, in fact, constitutes an important injury to apples, pears, plums, etc. The puncture differs somewhat from that made in the spring by the overwintering generation. The cavity is cylin- drical, as in the case of the spring puncture, but somewhat deeper, and is usually excavated beneath the skin all around, as far as the length of the snout of the beetle will permit. The opening through the skin, about one-sixteenth of an inch in diameter, is surrounded with a darkened circle, due to the cavity beneath, which, if the skin be removed, will be found to be from one-eighth to one-fourth inch across. Soc ae 79 12 LY ee PR Pes i pes DAN. he PER MSs oF wt 4, 404 1,970 Average per cent of infestation, 44.73. FRUIT PUNCTURED OR INFESTED. 137 Extent of injury to miscellaneous sorts of plums is indicated in Table LXXVITI. Records were made by gathering the specified number of fruits here and there from the trees or from the ground. It is regretted that similar data are not available from more ‘northern localities. Taste LXXVII.—Percentage of injury to plums by egg and feeding punctures, various localities. os Fruits | ? Average ae Peseta Date col- nec wee eas ak peter: Localities. Varicties. leeted unc. | feeding | jured per of | 28° of temarks. : Pores pune- fruit. feult fruit : tures. * | injured. 1908. Myrtle, Ga..... Wild plum..) Apr. 9 22 14 164 DOO liscecscteae From trees. 1D ees See Seen Gos ae 13 37 14 49 FOO Eee: Do. 1D Oy eer amen dos. 2. 20 43 6 | 51 14 0; 0)0) ee ees Do. Doma sera e Gost soe 22 36 10 | 4 110 ok eee saps From ground. TRO pee ee | nee GOs s- 30 36 5 9 BOM emeeecteza- From trees. iD fot 2e Seecnl eee dora 30 43 4 3 AOL soeee el ‘From ground. LD = eee) ae OGe sec. | May 8 36 4 | 10 SOM eee ere From tree. 10) oe peace do--s 8 32 5 | 13 E(t aes eee From ground. Dios eee | See do. | 31 22 5 23 Oh sees ae From tree. Moves hae Paley a eee 31 34 4 12 UN eee ee From ground. IDS ent eee eee dees June 6 7 3 20 DOM eee a semee From tree. pe ae ed ee ee Eee a 40 : i) 50 Jnseee2227- Brow pronnds [RE a) age (UOTE, ore 28 20 HON Notte rom tree. WDWaee ess secs Red June...| Apr. 9 4 6 90 | AOO) Bene seers | Do. iD = Seana eee Ox ee 14 | 61 13 26 LOOM ss eee Do. iD A ae Ree ee On: =e. May 7 | 3 5 17 | CITA Sak ess Sear Do. WO Sse seca! os do.2-=-- 7 | 32 Splbcee sees B5t lecomten ee From ground. 1905. Arundel, Md...| Burbank....| May 9 33 12 55 | 1OOG RSs as 22 From tree. iD) ne a5 c| Gee Ge aeaee 9 63 25 112 2,0) eae Do. Riverdale, Md.. (?) 26 117 4 18 TOON hee Do. Ome See: (?) 26 MPO | apse sate 2 1 DAN inl ee: From ground. Bennings, D.C. (?) 22 30 9 61 ALO DY ese a ee From tree. (iasecGnaee (?) 22 35 10 Lie BOE wag ee. From ground. at i Aiea 936 171|. 766 | 1,873| 59.10 | localities. . In the above table the figures for injury show merely the number of punctures. While most of the fruit punctured would fall, not all of it would do so, the fruit more or less outgrowing the injury. The average percentage of injury, i. e., 59.10, is therefore perhaps a little high. = The extent to which pears may be punctured is shqwn for two localities in Table LXXVIIT. As elsewhere explained, the real injury to such pears as Le Conte and Kieffer is small, as the thinning of the young fruit is in most cases desirable and the punctures are mostly outgrown by the fruit on the trees. 138 “THE PLUM CURCULIO. TasLte LXXVIII.—Percentage of injury to pears by egg and feeding punctures, Georgia and Maryland. . Fruits Average Fruits - . Total re peek Date col- | with egg with Unin- num- | Perecent- Localities. Varieties. : feeding | jured age of Remarks. lected. punc- fruit ber of ° irc punc- ruit. | frit. | . fruit tures. injured. 1906 Myrtle, Ga..... LeConte....| Apr. 9 11 7 182 200) a .ceeee ae From trees. Doe ares loca se dost==2: OM Sener m ce as | 12 188 200'|s Seen see From ground. LDL ps eeseeoe|eese Gone. 14 alos eee 93 LOD! asa. ae From tree. DOR ae oe 2 os eeees Colores ae 14 4 10 86 LOOT eee From ground. DOte aco e ese Gosveas: 20 11 4 35 151 0) Be Ee From tree. DOE sso ee ae doses =. 20 | 40 2 44 50) Scene o ee From ground. Dore nae doweeees May 2) 19 3 28 ‘ON tates From tree. Doses cee ee OOS 4 10 3 37 O04 ae From ground. Dos stsa-c4leeeee GOS las. 31 ffi 8 35 OE eee ....| From tree. IDYo yy 2 oat oe Keiffer <5. = Apr. 4 18 22 160 2004 Rance Do. 1D Ye eae een be ee Gotz ss 9 18 | 9 173 7/00) Retr Bae Do. Ose snore tare domeere. 9 Sul 5 152 Gig amare fe ee From ground. DOF se a eel ose GOees cree 13 29 12 59 LOOL Ras see From tree. DOr ee ea eee do. 52s.5 13 9 | if 84 LOO eee From ground. DOsse tes scale stees doetrene 20 25 2 23 0s eee From tree. WOee Fees eet dowee a= 20 13 | 3 34 50 \oseceeseoe From ground. WO een ela dossr-ae May 2 16 5 29 DO Eas see ae From tree. DOM eeeea|seace doses ace 4 18 | 7 25 DO shies ere From ground. OMe Al eee GOSS ae 31 10 12 28 SOk ESE a aatee From tree. Arundel, Md...| Bartlett..--- | 1D |e oe ees ee see 25 45) |e ee Do. Oe sie Keiffer....-. SDF 3 eth Be rae fet ee 42 oP) le ns Sm 3 Do. | Von SING | Moser Soe ees as.2/s acer 232 | 133 1,562 2.032 23. 12 average per cent of in- jury for both loc _li- ties. The extent of injury to apples in several localities during 1908 and 1909 is shown in Table LX XIX. These records are from unsprayed or control trees used in spraying experiments and demonstrations against the codling moth and plum curculio, and are further referred to under the heading of spraying apples (p. 193). TasLeE LXXIX.—Numober of egg and feeding punctures and percentage of injury to apples, including drop fruit and fruit from tree, various localities, for seasons 1908 and 1909. Aver- Feed- Total as Egg pi : age per- Localities. Variety. Date. tee pune- mg eee Lees centage - | tures, | Pune- | fruit. er of of fruit * | tures fruit. |. . | : * /injured. Anderson, Mo......-- Lansingburg. ..... Season 1908. 1} 1,486 438 166 1¢9 1D Yet pe a OS coe | Meee (slo yeaa ane ene Season 1908- Pale AE 542 298 308 OLE eS See IRS Se Goeet ees Season 1908. 3| 1,492 381 219 235 Doe ee eee eee doken eee ee Season 1908. 4| 1,615 448 284 298 NO aca Ss ee abe ee Clee eee eae Season 1908. 5 | 1,910 539 389 400 DO See a een eee Glo oe Season 1908. 6] 1,882 573 | 344 368 DGENI: Eee 25 el eee ee (tO rts ears Sea Season 1908. % | 254i 907 544 585 LD oS eee ae OL OS COE 26 eo ae Season 1908. 8 | 2,142 599 484 516 DO tee ater es oases doe ates Season 1908. 9} 2,021 752 566 626 Motalian diaver=1|s24-62 2 25 Janccce sao eee aneee aoe neenee 16,657 | 5,179 | 3,294] 3,505 93. 98 age per cent | of injury. Douglas, Mich... ...-. Ben Davis:,. 2... Season 1908. 1 538 301 274 751 DO eee cca ene eee GOB pee ce cee Season 1908. 2 916 282 316 592 DOr 550 et ee eee Gy Se eee ae Season 1908. 3 | aie Zan 740 528 944 DO eee | Hubbardstown....| Season 1908. 4: “1778 780 458 933 ND Yop spans Sea ail 2 Te Moments eas Season 1908. 5) 234sr 1,120) 10125| 735003, Dos enemas Oldenberg.......-. Season 1908. 6 | 9,482 891] 1,079} 1,182 Dez c. ee eee: sects GOneeece sees Season 1908. 7| 4,627 496 | 1,285 | 1,632 Notal and avers|*ac eae c ses se aero | Seen cee eae | meee 20,925 | 4,611 | 4,952} 8,987 55. 10 age per cent of injury. NATURAL ENEMIES. 1389 Taste LXXIX.—Number of egg and feeding punctures and percentage of injury to apples, including drop fruit and fruit from tree, various localities, for seasons 1908 and 1909—Continued. Feed- Total | Aver- as Egg Sti : age per- Localities. Variety. Date. Pree pune- ae Injured ikea centage : No. tures, | Punc- fruit. | ber of r | ures. | tures fruit of fruit 4 | * linjured. eee & Westfield, N. Y...... Baldiwinic ss vee 23 Season 1908. 1 139 52 181 748 Osean fe cee ites. GOs cece eee | Season 1908. 2 169 140 298 1,518 liek ae Se eee eee Co Ea ee aS Season 1908. 3 119 62 283 SSL 1D) Sah aes Re CES? eee Season 1908. 4 147 65 212} 1,100 Te epee ne eee (6 Lo ea | Season 1908. 5 191 121 286 838 eel ana Wallen oes Son ee Pos l| wnoceneacceect one se 765 440 | 1,260] 5,085 24.77 age per cent of injury. Grozet. Vaa-- <..=--- - Yellow Newtown.; Season 1909. 1 1, 670 1, 076 UGGS || Bie BS lO 23 Bape See re Gores ectc aces Season 1909. 2h G27 944 1571] 35682 GR ene Sone ol 5. Coe aes eee Season 1909. 3 479 226 437 816 ID GE 3 eee See Gores 95-258: Season 1909. 4 631 331 531 | 1,016 Des Se ees aie Cy See ee | Season 1909. Bele 4191) TOvt 1,415) |) 35100 DDL 5.5. a eee Se Ol Ee eae ata Season 1909. 6 | 1,068 871} 1,193 | 2,988 DYGE -'s 2 eet J COee ones Season 1909. 7 1, 433 865 1, 285 2,091 LD sues SS a ees Ors sae ee Season 1909. 8 aby 695 1,098 | 1,980 LN OLAS TING NES Cc) ce MRE ne eee el | teen rn | | So 9,497 | 6,079 | 8,785 | 19,107 45.97 age per cent of injury. Fisherville, Va....... NWanesapia ss 4-5 - Season 1909. 1| 1,326 536 | 1,350 | 4, 463 1D 2 5 at As See Ne tas CGE oer Season 1909. 2 WPal 389 799 | 3,134 DSP es oe eee Meee Gost tee eee Season 1909. 3 1,718 518 1,378 | 3,537 IDE age meee eee eee Ons a. esac Season 1909. 4] 1,573 378 | 1,420] 4,055 IDs 3 SE ee ee ee Coreen aa Season 1909. 5 | 2,793 795 |. 2,307 | 5,892 100)... 2os See ee ee ee COs es Cee Season 1909. 6| 1,019 206 803 | 2,244 Sree UP Tad) Se eee feos oral Seer c ce coke ee leat aca 9,156 | 2,822] 8,057 | 23,325 34.53 age per cent ; of injury. Mount Jackson, Va...} Ben Davis.......- Season 1909. To) DLS a 2S 217, 35186) || 3;,926 ID! oo ee oe ee eae GO Bop eee Season 1909. 2) 3,545 952 | 2,226} 3,109 LDS Sao eee | Se Gow tae ASeaee Season 1909. 3] 1,703 509 | 1,079] 1,840 DTS Asser ee eee) Se ee G10): Sapa Geneee Season 1909. 4) 2,179 709} 1,226] 1,508 ID OSS 2s aS eer ees Gon Saat Season 1909. 5 | 3,723 | 1,307} 2,399] 3,189 Thos OSs See ed eae (ky: Aree ee see Season 1909. 6| 4,113 | 2,009} 2,823] 4,153 LDS. Sees ne ee COPE ee eee Season 1909. Ze || BOGE) GAPART | Seioill | agate 1S eae ee | ae Gowan 5s. 2. a Season 1909. 8,785 |} 1,199 | 2,107} 2,795 Sirip aneurin een eae ey oe ee ill! ccs cle 29,708 | 12,140 | 18,657 | 25,641 72. 72 age per cent of injury. The injury indicated for apples ranges from 93.88 to 24.77 per cent of the total crop, both dropped and picked fruit. It is not to be inferred that the figures indicate the actual amount of fruit lost from curculio attack, since in many instances in the case of fruit from trees there would be but a single feeding puncture, or an old egg sear, largely outgrown. Such specimens, while unfit for fancy market fruit, would possess considerable value. NATURAL ENEMIES. There are many factors which taken collectively exert an important influence on the numbers of the curculio, as unfavorable conditions during the winter, drought during pupal period and time of emergence of beetles from the soil, scarcity of fruit for oviposition due to frosts or other causes, and the influence of parasitic and predaceous enemies and disease. Notwithstanding all of these, the insect is able to main- 140 : THE PLUM CURCULIO. tain itself most successfully, and puts in its appearance in the spring in numbers with much regularity. Under favorable conditions for development, as in neglected orchards, they often become excessively abundant, but for any locality do not show as a rule any great varia- tion in numbers from season to season. Although the cureulio in its egg, larval, and pupal stages lives well protected—as in the fruit and below the soil—yet it is subject to the attack of several species of parasites. PARASITIC INSECTS. (Anaphes) Anaphoidea conotracheli Girault. Only one parasite of the egg of the curculio is known, namely, (Anaphes) Anaphoidea conotracheli Girault, first reared by the senior author in 1902 at College Park, Md., and next from ma- terial collected in 1905 at Fort Valley, Ga. (See fig. 25.) The description of this species by Gir- ault will be found in Entomological News.!. These mi- nute insects, barely visible to the naked eye, are quite active, jumping readily when disturbed. This parasite ap- Fig. 25.—(Anaphes) Anaphoidea conotracheli, an egg parasite of the pears to be widely plum curculio. (Original.) \ LID distributed, and has been reared from eggs of the plum curculio in the fruits indicated, from the following localities: Taste LXXX.—Records of rearings of (Anaphes) Anaphoidea conotracheli, various localities. Localities. | Date. Fruit. Berlin, «Connisnoe-.a-nea nee sete eee July: 3-185 19052 cee. cee aes ee ace Plum. Wiashinetonb iCsce sae cee eee Mary 9-31 ".1905 S82 25s oa ee ne eae Plum, apricot. Colleper Park Md 3.22 s2ho8. 2 5oe5 see DULY 22-29 190 bse ee eee eee Apple. Riverdale MiGke a ssa See May 3- July 24 1905 cacao eee Apple, plum. Anmandels Maar. sssaatenue. tach May 16-June 15, LOO Sven see See Peach, pear, plum. Arlington, Via. ..--52 s+ De ene Junea3—July, 13° 1905-22. 4-5. see Peach, cherry, apple. Alexandria. \Viateto.22 cone sees .aa sie June 15-16, 1905. Saas cscs ae Apple, cherry. MastiballsiChurchViesses eee: ) a) Ae ho 190 bese ae Apple. WiGLOLIA, LOkzop ee aoeeseee ee ices =a |) Jaume 15 L005 secre. ee eee Plum. Tryon, iS SE apelin ein May: 20519052 3-2 cies ae ee ee Do. Lexington, Reyes Sock 2.1) Jen SOO 5 aes yee ae eee Do. Ardmore, Okla.. oa May/30, G05 sae ene ---| Wild plum. Fort V alley, Ga. .| May 9-June 28, 1905... . Wild plum, Japan plum. Myrtle, Ga... 2.2. .--| Apr. 26—-May 138, 1906. Wild plum. Charlottesv ille, Va.. ee || Mayas 190 rec pes eee : Apple. Barnesville Gat w-\secemee one ee May 17-26, 1910......-- Wild plum. 1 Ent. News, vol. 16, p. 220 (1905). NATURAL ENEMIES: PARASITIC INSECTS. 141 From the records from localities in the environs of Washington, (College Park, Riverdale, Arundel, Md., and Arlington, Alexandria, and East Falls Church, Va.) it would appear that the insect is out ovipositing nearly coincident with the period of oviposition of its host, namely, May 3 (Riverdale, Md.) to August 12 (East Falls Church, Va.). Rearings have been made from eggs in various fruits, including wild and cultivated plum, and it is probable that the parasite will search out eggs in any fruit used by the curculio for egg laying. In its distribution the Anaphoidea is seen to range pretty well over the Eastern States, and rearings from Ardmore, Okla., indicate its occurrence in the Southwestern States. The insect probably follows its host, though no data of note are at hand as to its distribution in the Mississippi Valley and Middle-Western States. In several instances it was possible to determine the percentage of parasitism of the eggs. Thus, in a lot of eggs from Arundel, Md., in plums collected from trees May 9, 62.8 per cent yielded adults of the Anaphoidea. In another lot from the same locality, on the same date and host, the parasitism amounted to 70.76 per cent. A lot from Berlin, Conn., in plum, gave about 85 per cent parasitism. At Myrtle, Ga., eggs in wild plum collected May 16 gave 10 per cent, and another lot taken May 1 gave 16.6 per cent parasitized. From Bennings, D. C., a lot of eggs in plum taken May 31 gave 12.2 per cent parasitized. Of 36 eggs collected at Barnesville, Ga., May 17, 36.11 per cent gave out adult parasites. In a lot of 28 eggs collected May 19 the percentage was 46.43, and of 97 eggs collected May 26 the percentage producing adult parasites was 56.70. In these three lots, if account be taken only of the eggs which either hatched or gave out adult parasites, the proportions parasitized would be 46.43 per cent, 76.47 per cent, and 91.66 per cent. Five eggs in these lots produced two parasites each. Certain observations on the habits and biology of the Anaphoidea parasites, made by Mr. Girault, are of interest, especially in view of the paucity of our knowledge concerning these minute creatures. Parasitized eggs were found to maintain their normal pale white color until within two days of the emergence of the parasite, at which time or a little later the large reddish eyes and the three reddish ocelli between them become evident and the general outline of the parasite becomes discernible. Gradually the parasite becomes dusky and a few hours before emergence almost entirely black. The time required for the development of Anaphoidea from egg to adult varied from 9 to 11 days, averaging approximately 10 days. Thus during the 6 to 8 weeks of egg laying of the curculio there would be time for six or seven generations of the parasite. Oviposition was observed several times. In a typical instance, the female carefully examined the egg puncture, which was two days old; the long flexible antenne moved alternately up and down very 142 THE PLUM CURCULIO. rapidly, tapping the plum. After an instant of greater excitement she suddenly stopped, with body raised, holding the antennz straight and rigid before her. The slender ovipositor was quickly inserted, the tip of abdomen being bent cephalad for the purpose. Oviposition occurred within 30 seconds. In removing the ovipositor the antennze were lowered partly beneath the fore-body, evidently as a help, and the abdomen quickly arched. (Sigalphus) Triaspis curculionis Fitch. The Sigalphus parasite of the curculio (fig. 26) was first discovered by Dr. Fitch, and a description with figure of the female published in the Country Gentleman for October, 1859 (p. 221), and also in the Albany Cultivator in October of the same year. A more extended account is given in his address ‘‘On the curculio and black knot on plum trees,” delivered before the New York Agricultural Society in 1860. The specimens upon which the description was based came from D. W. Beadle, St. Catherines, Ontario, and had been reared by him from black knot on plum trees which were infested with curculio larve, the adult curculios appearing in numbers in the rearing jars. The fact that the black knot is also infested Fic. 26.—(Sigalphus) Triaspis curculionis, an important parasite by the larvee of other in- of the plum curculio: a, Male; b, female; c, antenna. (After sects, especially that of eae the so-called plum moth (Enarmonia prunivora Walsh), casts doubt on the exact host relations of the Sigalphus. In fact, Walsh in his report as acting entomologist of Ihnois ridiculed the idea that the Sigalphus was a parasite of the curculio, and this doubt was not removed until 1870, when Dr. Riley reared the insect in large numbers from curculio larve placed in jars in carefully sifted earth. Little has been added to our knowledge of this insect since the observations by Riley. Prof. Gillette, in Jowa Station Bulletin 9, page 378, gives some interesting notes on the insect; he found it quite common in the vicinity of Ames during the summer of 1889. The variety rufus Riley, later mentioned, was four times as abundant as the true curculionis. The substance of the same article was also published in the Canadian Entomologist, volume 22, page i114 (1890). The Sigalphus has been reared by Fayville and Parrot, in Kansas, from larve of the potato stalk weevil, Trichobaris trinotata Say (Kansas Station Bulletin 82, p. 12), and the parasite is recorded from the same host by Dr. Chittenden (Bul. 33, n. s., Bur. Ent., NATURAL ENEMIES: PARASITIC INSECTS. 148 U.S. Dept. Agr., p.17). The insect was reared from the cotton boll weevil (Anthonomus grandis) at Calvert, Tex., and is doubtfully recorded from Conotrachelus juglandis Lec. Specimens of curculionis were also received from Prof. A. H. Conradi, Clemson College, S. C., in 1908, and from Prof. Fred E. Brooks, Morgantown, W. Va., Jan- uary, 1907, who had reared them from Balaninus sp., As stated by Mr. W. D. Pierce (Journ. Econ. Ent., vol. 1, p. 386), it com- monly attacks Conotrachelus elegans Beh. at Dallas and Victoria, Tex. At Four Mile Run, Va., it was reared from Trichobaris trinotata Say in eggplant. Riley records the Sigalphus from a stalk-borer in Ambrosia (Ins. Life, vol. 2, p. 353). In West Virginia it has been reared in abundance son Conotrachelus affinis Boh. and in lesser numbers from C. juglandis Lec. (W. Va. Agr. Exp. Sta., Bul. 128. p- 182). This, so far as the writers know, is the complete host list of the species, and Sigalphus is so much more common on Conotrachelus nenuphar that this is without doubt its principal host. (Sigalphus) Triaspis curculionis is of general occurrence througn- out eastern North America, its range probably being coextensive with that of the plum curculio. .81 9 0/4 O}s 819014 o> 81m 0|4 Ole A ial ial ie clic Sl cl cl SiS Wane 256-28 sods ot eee ne seen 6 | 10 4| 2 i Baec:| es 4] 6 2) 1 1 DOse oer eee ieeceeponse wees 4| 2 3| 6 PP eo eee | ei) || anes 40 4 eso OY (Se RA RO PO TS 4] 2 GHG ON oN ease |) woul oars (5 ore DBS ick es cicte at atebine e oeise neeaenee 7 Mise? 2 Viteal fe | Hamn 30) [pew fe Peal Rae: ©) Vr 1 Vee | La 4] 5 1 Totaloe.s es so aese eee eee SCS Tel aK eG RM SRY ae ei ayall ey ess e)| alge | a7 2 Beetles alive at close of observations..| 4] 4]19] 1] 4]17]| 7] 3/19] 3] 7 20 3] 18 The results uniformly show a prompt killing effect on the beetles by the arsenate of lead on the varieties of fruits used. It is also evident that the insects feed freely during midsummer. During 1910, in Georgia, numerous feeding tests were made using several of the more important brands of arsenate of lead, as well as other miscellaneous arsenicals. In Table XCI are given results of feeding tests on peach twigs taken from trees in orchards immediately after spraying, April 13 and 14, and placed under cylinders. April 16, 50 beetles were added to each cylinder and records made daily of the number of beetles dying. The poisons were used of the strength indicated in the foliage test experiments (p. 205). The killing efect of all of the poisons was fairly prompt, the various brands of arsenate of lead working fairly uniformly. Red arsenic sulphid and arsenic tersulphid were quicker in action than the lead arsenates, although, as elsewhere noted, these poisons were notably injurious to the foliage of FEEDING EXPERIMENTS WITH POISONS, 187 peach. Ferrous arsenate was much slower in action, but effective, as shown by comparison of the condition of beetles fed on poisoned foliage with the condition of the beetles on the check. Taste XCI.—Tests of killing effect of lead arsenates and other arsenicals on the plum curculio on peach, Georgia, 1910. Beetles dying from each of the arsenicals. Dates of Arsenate of lead. Pow- death of : Reed Fer- | Red | Arse-| Arse- nine GAC fe a eres | ands | erse: | ale || nde not . n rte arse- aL La a sprayed. - Tan 6 ‘ 4 Atal SLs eSULt=aSUil= No. 1.|No. 2.|No. 3./No. 4.|No. 5.|No. 6.|No. 7.|No. 8. aa nate. phid. phid.'phid. JM oes U7 359] Glee eed REREEe Baeepc eeceso) oer Sl Beooee| Geeon | Botces | dees closscae| Rensbdl easaee SIN oer RS) eee 4 LO eistercicts 4 8 4 4 4 I) \eclsose 9 tbe | ace [ht ea] ReSSaooo- 2 3 4 1 5 7 8 16 1 1 9 163) see re 1 8 3) |ssce¢ 5 3 2 3 7 2h |laepae 3 tbs eee SS ”) 1 9 12 7 6 4 6 lil 4 5 2 8 CS eee Se 2) oaveel| se aSe0 ce 7 6 5 10 9 5 6 4 | |beease 2 5 1 73 | SECee nee 8 13 8 7 5 10 10 7 5 3 6 2 6 07 Se ee eee oe 2 2 8 8 7 3 1 5 7 2 3 1 8 Perse BOROORIIE 3 1 5 5 4 6 3 1 6 3 Ul \eeeee 11 PRR Sel Pe Baasar 3 2 3 1 2 1 2 2 5 uh 42 \[ooecce 3 2 2 4 i! 8 1 1 1 7 1 1 3 2 1 1 Duplicate test started Apr. 20. In Table XCII are shown results of feeding tests with several mis- cellaneous arsenicals, as specified, used in the self-boiled lime-sulphur wash and simply in lime water. As before, twigs were cut from peach trees in sprayed plats in orchards and placed under glass cylinders. Spraying was done April 28 and 30, and 50 beetles were added to each jar April 30. The beetles in all of these tests were fresh, having been jarred from peach trees a day or so previous. An accelerated killing effect seems to have followed the use of the com- bined self-boiled and arsenical sprays, as compared with the arsenical used alone. The comparatively slow action of arsenate of iron is again noted, though when used in the lime-sulphur wash it compares favorably with arsenate of lead. 188 THE PLUM CURCULIO. Taste XCII.—Tests of killing effect of various arsenicals on the plum curculio on peach, Georgia, 1910. Beetles dying from each of the arsenicals. . . A . Arsenicals used without Arsenicals used in self-boiled lime sulphur. lime sulphur. Dates of death of beetle. | 3 che | ick: a = Bop ira BS £ 3 2 alege ae a pee ee ciceeleeae e . | 2 | 88 |se| ee] 28/8218, |2e | sale) ee na ° og Bi Firgy Hw Bo ma ay 2 wm aS 2] 2 | ob| 32/58 | os| 2S) $3 | 2b | 28 | ts | 28 mw | @=| 88) 86) 92) ba) eo) Ss” | eee eae 2\ 218 |2 |@ |Seise a (8 12 |sale GS fod. | md fet ee | eo ee Maya) st oe een Sets 2 A eas, 11 2 11 3 1 7 3 1 See cee Aa Serie saree |= sete 5 4 | 3 8 2 ft Bulseoeee 1 16 6 ae a ae Peete 1 6 3 1 it 5 15 8 2 1 3 3 eee As eee a Woca ac 7 4 | 3 5 12 8 7 5 1 2 3 eee Rasen ss saa ecrsrne 11 5 10 2 9 1 20 2 4 1 5 pop ene 5 See 1 9 9 10 8 8 3 6 8 9 8 4 SIA aS aca aoe ecaae 3 3 2 5 1 1 Se 1 4 9 4 ee Se een Herc se 2 1 7 1 3 1 1 4 2 5 10 (US eae ce naan Soe aiseocdac 4 2 1 Pees ae 1 1 1 2 4 1 4 3 Si |acseme in| BAe Soe aoe 5 1 2 3 2 3 1 Uh Bet ese Paeese 4 BA Beene 3 6 1 1 Bae Resse Meeenn Base c|oo5accleoaccc 1 2 1 2 A feeding test was made with beetles in lots of 50, using twigs bearing fruit and foliage from sprayed trees in the orchard, except in case of lot 6, where foliage had been removed. Trees were sprayed, April 4 and 5, with arsenate of lead at the rate of 2 pounds to 50 gal- Ions of water, and feeding tests started April 5, except with lots 7 and 8, which were started April 7. It will be noted that all the beetles on the sprayed branches were killed within about a week, except lot 6, where fruit only was present and the period was length- ened. (See Table XCIII.) SPRAYING FOR CURCULIO ON APPLE. 189 Taste XCIII.— Tests of killing effect on the plum curculio of arsenate of lead sprayed on peach foliage and fruit, Georgia, 1910. Beetles dying in each lot. Lot 7: Lot2: | Lots: | nota: | LOE | rote: ) Lot 8: Date of death of Un- 3 rayed Un- g raved Un- Ss srayed Un- Sprayed beetle. sprayed tet & sprayed | ~ Poe sprayed | * ae sprayed eis twigs uf & twigs ihe twigs As twigs Aves - with us with a with af with wit Si with 7 with . with : Raina fruit and foliage foliage fruit fruit friend fruit and foliage. | foliage. only. only only only foliage. foliage. Condition on Apr. 17.| Lot 1. Lot 2. Lot 3. Lot 4. Lot 5. Lot 6. Lot 7. Lot 8. Motalduede:ss= 5. 2c. 7 47 10 50 2 37 2 £0 DUIS Be Ae Seer gee BQN Ecosse OO) tee sees 46 9 AGy | eee. Mseaped): <<. =< .=--- a 1 3 Cal kage 2 a Mal econ econ Some feeding tests made by Mr. Johnson to determine the possi- bility of preventing the fall-feeding punctures of the curculio on apple are interesting: August 17, a branch of Baldwin apple tree bearing fruit, after spraying with arsenate of lead at the rate of 3 pounds to 50 gallons of water, was inclosed in a cage with 50 beetles. Twenty beetles had died by August 28. An examination of the apples showed 3 without punctures and 8 with punctures, as follows: Fruit No. 1, 5 punctures; Nor2.1+ No. o,14:,No.4, 15; No.5, 16; No.6,;28; No. 7,41; No. 8, 49; a total of 175 punctures on the 8 fruits. The condition of a check branch bearing 8 apples on this date was: Fruit No. 1, 66 punctures; No. 2,14; No. 3,45; No. 4,18; No. 5, 26; No. 6, 58; No. 7, 23; No. 8, 63; a total of 343 punctures. None of the beetles was dead in this cage and the punctures were much larger. SPRAYING FOR THE CURCULIO ON APPLE. EARLY EXPERIMENTS. The first experiments of which we are aware, made to determine the value of arsenicals in the control of the curculio on apple, are those reported by Forbes in 1885, and already referred to (p. 181). In this work 8 trees were used, 4 of them being sprayed and 4 re- reserved as checks. Two of the trees were treated with Paris green, 1 with London purple, and 1 with lime. Two applications were 190 THE PLUM CURCULIO. made 8 times, beginning June 9 and continuing until September 3. The two trees sprayed with Paris green at the rate of 1 pound to 50 gallons of water showed a benefit in lessening curculio injury as com- pared with the unsprayed trees of about 50 per cent—more exactly, 72.70 per cent of the fruit was uninjured as against 42.70 per cent uninjured on the unsprayed trees. The trees that had been sprayed with London purple gave 61 per cent sound fruit as against 62 per cent fruit from the unsprayed trees. Jn conclusion Prof. Forbes states: Furthermore, if we must judge from results thus far reached, these various appli- cations are all of too slight effect upon the apple for plum curculios to make them worth use against these insects, Paris green diminishing curculio blemishes less than one-half, London purple about one-fifth, and lime not far from one-fourth. No further experiments seem to have been made until 1900, at which time Prof. Stedman began an investigation of the curculio on apple, which was continued during 1901 and 1902, the results of which are given in the bulletin of the Missouri Agricultural Experi- ment Station No. 64, published in 1904. Experiments in spraying apples were made in three different orchards. It was desired to test the practicability of killing the beetles while they were feeding on the leaves before the appearance of the bloom. One-half of each orchard was sprayed twice from the time the leaves opened until the blossoms opened, leaving the other half as check. These exper- iments were repeated the following year, and in addition four appli- cations were given after the falling of the blossoms at intervals of 10 days. By this means about 60 per cent of the fruit was protected in spite of reinfestation of the sprayed trees from the unsprayed part of the orchard. The desirability of spraying the entire orchard to prevent overflow was pointed out, as under these conditions the benefits would be very marked, and the great bulk of the “‘stings”’ would be prevented. In the report of the Illinois State Horticultural Society for 1902, page 158, Prof. E. S. Titus discusses the plum curculio under the saption “Insects other than the codling moth injurious to the fruit of apple,” and gives results of observations made at the instance of Dr. Forbes. In regard to the use of arsenicals he says: The experiments tried in the Illinois entomologist’s office several years ago showed very clearly that the curculio may be killed by spraying trees to which it resorts in early spring with Paris green or other arsenical poisons, as it feeds at that time largely on youngleaves. Consequently, other things being equal, that orchard will be least infested and its fruit least injured whose trees are sprayed early in the spring, as for the codling moth or canker worm. On the whole, however, much the most promising and important measure is the prompt destruction of fallen apples to prevent the escape of the curculio larvee into the earth, after which it is almost impossible for these larvee to go through their usual transformation. SPRAYING FOR CURCULIO ON APPLE. 191 The first attempt, however, to determine the possible value of the use of arsenical poisons in the control of the curculio on apple on a commercial scale was begun by Prof. C. S. Crandall, of the Illinois Experiment Station, in 1903. His report of operations for that year was read before the Illinois State Horticultural Society (vol. 37, pp. 176-189). Two blocks of sixty 18-year-old trees each in two different but adjacent orchards were selected. In the Williams orchard the soil was covered for the most part with a bluegrass sod with a heavy surface mulch of dead leaves and grass. In the Blair orchard there was no sod but a scattered growth of plants, including grasses, and the surface mulch of leaves and trash was lighter. From 7 to 16 applications of an arsenical spray were given to the respective plats, including Paris green, arsenate of lead, white arsenic, and arsenite of lime, the first three treatments in Bordeaux mixture and the sub- sequent ones in water. During the course of the work 29,943 apples were examined. In commenting on the results, Prof. Crandall states that the spraying did not control the curculio. Apparently the frequent spraying had some influence because the percentage ot uninjured fruit from the plats sprayed 16 times was a little higher than from any other plats. Three reasons were assigned for the unfavorable results, namely: 1. Weather conditions of early spring and their bearing on the crop. 2. Location of the plats directly in the midst of large orchards con- tiguous to native woodlands. 3. Unusual abundance of the insects. On the Williams orchard the percentage of sound fruit varied from 1.26 to 5.29, with an average for all plats of 2.76. Results were somewhat better in the Blair orchard, the percentage of sound fruit ranging from 2.55 to 16.07, with an average for the several plats Gf 7.1. Prof. Crandall continued his work during 1904, as reported for the Illinois Horticultural Society (vol. 38, p. 75), and selected a somewhat isolated 5-acre orchard, thus eliminating invasion by the insect from outside sources. This entire orchard was treated, except the 13 check trees. The ground was not in sod and the orchard had never been sprayed. The spring weather was reasonably favorable and the trees bore a fair crop of fruit, and the curculios were much less abundant than in 1903. The schedule of applications was the same as employed in 1903. > >*>> 4 1204 156 ZACH |e Nee 27, June 8, June 27. 5 | 2/829 207| 92.60|.......... 11, 427 O21GU S. eee Se 91.07 1 748 191 TASAO) toe cle mae = 2 1,518 309 79s GON seen cs MiSes.|| Unsprayed x. \cntne-e> oaeince se ece esos. G ean 3 862 181 79:00) | sae Ses 4 1,100 212 80: 80)|ss-o-62--~ 5 838 312 Priel eee ee 5, 066 ADA NG}s| oe eee 76. 21 NORTH EAST, PA., 1906. Two applications Bordeaux mix- SKS 1 802 156 SOLO4ofee he ces aso? | ture (4-450) plus 2 pounds peice Old 2 541 iy HEL 9 is [ae Sa arsenate of lead: May 24, June 7. 5° 3 370 49 tS ay fe ae eee 1,713 61S Ree anaes 79. 04 1 647 473 26589 eeeciciee PeameWUTSUTAVE . S22 5. - 2b facies. e853 eee. GOrss eee 2 268 223 WGAGn eae cote ics 146 95 SY ASH pee pene 1,061 TOls| ones eae 25. 44 196 THE PLUM CURCULIO. EXPERIMENTS AT SILOAM SPRINGS, ARK. In the one-spray versus demonstration treatments for the codling moth and apple diseases at Siloam Springs in 1909 special attention was given to determining the effect of these treatments on the cur- culio. The results from only Plats I, [V, and V are given as consti- tuting the principal features of the work. The orchard was an isolated one and contained 344 trees and was divided into five plats. There was a miscellaneous assortment of varieties, but principally Ben Davis, on which variety all counts were made. The treatments which the respective plats received are shown in Table XCVII. Plat I shows an increase in uninjured fruit over the unsprayed plat (Plat V) of 77.20 per cent, and there is a difference in favor of Plat IV of 3.74 per cent of sound fruit. It will be noted that one drench- ing spray in this instance gave somewhat better results than five applications, though this condition is probably to be accounted for by reason of the proximity of Plat IV to the check plat. Taste XCVII.—Results of spraying apples for the plum curculio, Siloam Springs, Ark., 1909. Total ? > Average Plat Tree | Total | number ie E a percent- 2 Treatment. Variety. ‘| number | of apples as age of No. No. of pune- | sound ofapples.| punc- aes sound Fareds tures. apples. apples 1 5, 689 1, 179 1,979 rit Pe-{ il eee One spraying only with - ee ne a te a ae rere bea arsenical; drenched 4 2 750 387 ” 683 ahs ll (ela ae with arsenate of lead, 5 3) 446 208 268 aac05 CM eae 1 pound to 50 gallons “ ; uaae Be Beal ia ea " Weare c a Ben Davis.. 6 3, 768 532 1,012 85 88) aaoseee oe water, Apr. 24-25; Bor- 7 3° 307 370 638 88. 81 deaux mixture only 3 5 4 43 706 1 200 Sr pol ee (44-50) May 25-26, 9 3, 644 364 642 90 sO1 a aoe es July 2. 10| 23.652 216 ATH PREC |Rn cee 11 8, 895 335 642 OLSON | ee eee 43, 203 5,899 Wel es eeonpac 86. 34 1 3,536 746 1,293 48590) |neicrere eis.ereve 2 1, 890 301 562 84.07 lncemeaooes Five applications Bor- 7 aie oh ue ae Be Seca deaux mixture (3-3-50) 5 3’ 145 266 430 91. 54 Peniaieiccisieis IV plus 2 pounds arsenate Go 6 e 663 200 432 87. 98 gee cece F of lead: Apr. 24-25, sae ss eit 2 9’ 496 498 1.025 90,04 eee May 25-26, July 2, 8 3172 467 877 so ece ee July 22, Aug. 10. 9| 4701 || 4j686)) -S)layr| Pa Beet eee ee 10) 1,957 140 254 OD) BA lees ASS eae il | 3,058 769 1, 429 TA BoA seh Beets | 32,451 5,554 10,302 | = i) 2,560 2,130 6, 623 2 1,701 1,595 6, 230 3 995 948 4,331 4 1,538 ia2e 10,068 5 | 1, 206 999 3,372 6 2,501 2,299 9,527 Vieoae | UmSprayeds. oo -.:-ssesslsoces Osea s2= 7 2,821 2,724 14, 727 8 1,156 1,070 4,714 eae 9 2,323 1, 936 6, 143 G65) | ezeecceeame 10 2,258 2, 117 8, 707 6.24 | ccs caeeee i 1,719 1,605 6, 921 663) (see 12 1,608 1,517 5,984 DHOON ocean eae 13 2,060 1,750 6, 739 15304 a eee 24, 446 22,212 94,086 |...-.<-... 9.14 Bul. 103, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XV. Fic. 1.—DUCHESS APPLES FROM TREES IN UNSPRAYED PLAT. (ORIGINAL.) Fic. 2.—DUCHESS APPLES FROM TREES IN PLAT SPRAYED AGAINST THE PLUM CURCULIO WITH ARSENATE OF LEAD. (ORIGINAL.) BENEFITS OF SPRAYING FOR THE PLUM CURCULIO. SPRAYING FOR CURCULIO ON APPLE. 197 EXPERIMENTS IN VIRGINIA. Experiments in Virginia during 1909 were carried out in two localities, namely, at Crozet, in the orchard of Mr. W.S. Ballard, and at Mount Jackson, in the orchard of the Strathmore Orchard Co. Orchard of Mr. W. S. Ballard.—This orchard is located in the eastern foothills of the Blue Ridge and is composed mostly of the Yellow _Newtown variety, which sort was used exclusively in the experiments. The surrounding trees not used in the experiment were sprayed by the owner. This work formed part of the ‘“one-spray’’ experiment, and especial attention was given to determining the effect of the treatments in lessening curculio injury. Four applications gave a percentage of 86.89 sound fruit as against 54.02 on the untreated trees, a difference of 32.87 per cent. One single drenching applica- tion protected from the curculio to an extent of 73.93 per cent, an improvement over the check of 19.91 per cent. (See Table XCVIII.) 4 | TaBLE XCVIII.—Results of spraying apples for the plum curculio, Crozet, Va., 1909. Total ? . Total | num- sul Per- fe ae Plat ; peta nti Tree | num- | ber of , | centage] “o- Fe” re Treatment. Variety. No. | ber of | apples ber of Besound centage apples. | punc- | PY | apples. |ofsound "| tured. | tures. PR apples. 1 802 115 15K |) 285166 kee - 2) 1,459 187 LOW Siew Peace oss Four applications Bordeaux mix- 3 719 103 TGS | SonOla |p aces I ture (2-2-50) plus 2 pounds ar- ||\Newtown 4) 25415 345 Dede Oo ile eee ae senate of lead: Apr. 27, May 24, Pippin. 5 | 2,032 463 GOSH 27.21) Es as ns = June 26, and July 26 and 27. 6] 1,308 114 162) lo QU 28% [he 2 7} 3,014 267 395) || Mista be sess oe 8 | 2,328 252 PASS leetess Hel lig (ee Aa VASO7 7, 1846) | 25672) | o:'- 2 &6. 89 1 2,578 961 1,510 G2 57 2HE Soon eee 2| 2,533 HoOh|| Ab 2oO lh taeda we ae One spraying only, drenched with SueosOoe ls ust lee asall wrosol ene a ee II Bordeaux mixture (2-2-50) plus ale 4] 1,318 238 S60) | SlaOa Ee = see >>|)’ 2 pounds arsenate of lead, Apr. |(7>"> ~~ >>> >>> 5] 3,245 MOT | TS O95) | Wire 84 |b = cee ‘ 27. 6] 1,979 405 647 kt Se | eee 7 2,041 521 775 MAGI? |B oe ae 8} 2,039 511 URE EACR. | Seeeseee 20,838: | 5,432 | 8,643 }_......- 73. 93 1 3,423 1,255 2,746 ae Sl peeeoees 21 3,682) VU, 57 | 2,571 HYERE I Paeedace 3 816 437 Odie Abs 45 Es eae + 4 1,016 531 962 yA By See oe ee IIT...| Untreated..-.....--.---++-.2--+--]----+ do...... 5| 3,111| 1,415| 2,490] 5452 ]........ 6 2,988 1,193 1,939 GOROGL IEE ee tf 1,980 1,098 1,865 Ett: sy See ee 8 2,091 1,285 | 2,300 Be hb7 et eee 19,107 | 8,785 | 15,578 |........ 5A. C2 198 THE PLUM CURCULIO. Orchard of the Strathmore Orchard Co.—In the Strathmore orchard, at Mount Jackson, the curculio was notably more abundant, and the results were less favorable. The orchard had been in sod for some years and conditions were thus favorable for the insect. All trees not included in the experiment were sprayed by the owners. The results indicate the impracticability of satisfactorily reducing curculio injury by spraying alone, when conditions are extremely favorable for the insect. Three applications protected the fruit to an extent of 40.82 per cent as against 27.23 per cent on the unsprayed trees, a gain of 13.59 per cent of the crop. Curiously, the single application, given to Plat II, resulted in a higher percentage of sound fruit than the three treatments given to Plat I, namely, 57.90, an increase over the check plat of 30.67 per cent. TaBLE XCIX.—Resullts of spraying apples for the plum curculio, Mount Jackson, Va., 1909. Total | , Total | num- eee Per. cae See Plat Fie ee Tree | num- | ber of = centage|“o-# Nat Treatment. Variety. No. | ber of | apples ber of |orcound| centage apples. | punc- punc- | apples ofsound Ilene tured. | tres apples: | apples 1 1866::1' 15367 ||) 2,961 "| 926: 74 boos ee : 2} 1,308 ODEN goon) Taeneee eee see Three applications Bordeaux mix- 3:4) 35466 1) 16315) 8067)" 52.04 ee I ture (1-1-50) plus 2 pounds ar- BenkDanis 4 708 441 OBZ Orla Meee Faia senate of lead, May 6-7, 28-29, oe Sil) A660 a 2575 SOLS |) 24209n hoses July 8-9. 67) 35486-25197 4 0404) AR Oise 7 1,063 612 1,486 4D. AD heer 8 |) 2;429 "| 1,382 | 2.869)" 48:30 sess 16,293 | 9,642 | 20,759 }.....--- 40. 82 1 3,827 1,507 2, 782 60: .62)\bess eee One spraying only, with arsenical. 21 8,657) 788) 2,800) |) Slaton eaeeeee Drenched with arsenate of lead, 3 675 303 633i) soba eee Tl 2 pounds to 50 gallons of water, ale 4 989 494) 103241) B00b) eee eee Ste May 6-7. Bordeaux mixture |{[---~ ~-"~~~ 5} 1,679 754 | 1,449°| 55.09 |: -2--- 22 only (2-2-50), applied May 28-29 6 3, 480 1,212 2,159 65c17 aes and July 8-9. 7 969 447 O87, |. 58.805 |seeaceee 8 {| 4,299 | 1,785 | 3,153 | 59.64 }.......- 19,5755 (8, 240913995) | eee en ee 57. 90 uy 3,926 8,186 7,336 LS. 84 0b eee 2 3,109 2, 226 4,497 28:40 |b seen 3 1,840 1,079 2,212 Al, S65 | beac 4 1,508 1,226 2,888 18269) Bees. cer III...) Unsprayed.......-.------+------+-[----- do...... Ble Se80))|) 239905030. | meee ca | ema 6 4,153 2,823 6,122 32h 08H oseaacs 7 5,121 3,611 8,779 29; AS: Pcmmer ae 8) 25795.) 2 107.)|) -4,904)|) 2461) | Peeeeees EXPERIMENTS AT ST. JOSEPH, MO. The work at St. Joseph also formed part of a demonstration sched- ule of spraying in comparison with the one-spray method. The orchard used had been in sod for some years, and no spraying had been done. Conditions were especially favorable for the insects, and, as shown by the tabulated results below, the injury under these conditions was very severe. The crop, moreover, was light by reason SPRAYING FOR CURCULIO ON APPLE. 199 of late spring frosts, which served to concentrate the injury. Unques- tionably a part of the loss shown was due to the apple curculio, which was abundant in that locality. At the time of the first application, May 16, the petals had just fallen from the trees. The St. Joseph results present some points similar to those obtained the same year at Mount Jackson, Va.,—namely, that when the curculio is excessively abundant, satisfactory results may not be obtained by spraying. Plat I, which received 4 applications, shows only 50.10 per cent of sound fruit as against 4.05 from the unsprayed trees, representing a gain of 46.05 per cent. The single drenching application, given to Plat II, resulted in 36.80 per cent of fruit free from cureulio, a gain over the unsprayed block of 32.75 per cent of the crop. TaBLE C.—Results of spraying apples for the plum curculio, St. Joseph, Mo., 1909. Totals (ra ies + Total | num- on Per- ae = at ; rats Tree | num- | ber of 7 jcentage|/-o- F APal Treatment. Variety. No. | ber of | apples ber of of sound] CeDtage apples. | pune- | PY | annles. ofsound tured. | tures. apples. Four applications Bordeaux mix- ae ; : 5 I ture (44-50) plus 2 pounds ar- Ben Davis. -| ; To a be 2 55 pee SN -----l) senate of lead: May 16, June 9, A 31 157 844 2’ 012 46. 54 apa ae July 9, and Aug. 6. 298 = UES See 4,950 | 2,470} 5,810 ].......- 50. 10 One application. Drenched with Sa = ii arsenate of lead, 2 pounds to 50 dowsae { =, aden Pee ees . oS ae Paes gallons water, May 16. , it z SNS) ceo 5, 788 3,658 | 9,290 }.......- 36. 80 1 1,694 1,625 7,715 ty el EE = = PME MUO MSPTAVOGs ss so0s56 5005 s5s5-5ss5[52 oe doe saeer 2} 1,437] 1,398 | 8,577 2 AC yh Ores ae 3} 1,358 1,284 | 5,275 AS: ee 4,489 | 4,307 } 21,567 |-.--..-- 4.05 The records above given in spraying apple orchards for the cur- culio are assembled in Table CI, which indicates, in average per- centages, the amount of uninjured fruit from each plat from the several localities, arranged according to the number of applications given. These experiments have extended over a period of several years and were made in various places, so that the results are not entirely comparable. Even when considering the results of indi- vidual experiments, a wide variation is seen in results from orchards which received practically the same treatment—for example, in the two orchards in Virginia sprayed during 1909. 200 THE PLUM CURCULIO. Taste CI.—Summary of results in spraying apples for the plum curculio, in average percentages of sound fruit, various localities. Localities. Treatments. . West- Siloam Mount St. nag Ander- North : Crozet Illinois. oe Mo. feld, East, pe Springs, ve ’ Jackson, Joseph, deapplication.... <<< 2: shoes 2 SeSese bec cacsosd ence Se eel eee eee 86. 34 73. 93 57. 90 36. 80 Dapplications. «... 522-2. .scesce|oe ww cse eee lsc oeeacet OSU BE e cd |spocnbobed pecooaSlzes|leoonce tons sapplications.. -..<2 2. 2) /J. ‘ = I.....| Three applications, 2 pounds arse- |{ |, 773 ees 14 |1, 217 21) 98.27 |.......- r pa Sr ars 211,067} 35] 67 7 | 741 ||. .d9u)), SO7 58) eeee ean nate of lead to 50 gallons water, Rie ¢ : 7 4 : es 3} 646 93° | 220 8 | 866 BL |’ 496742) Sees plus 3 pounds stone lime: Apr. ate = 2 o 57: May 8 and 20 4) 743)|' 4 |r B50.) 21,0031) altel POR neg a ae Seep ; 5| 423| 74] 179 9 | 602) “S3" |" Belair eaeeeeee 3,652 | 143 |1,867 45 |5,519 1634) See ee 6. 59 1} 393 37 Soilecesece 476 of | 92022 [oso oees II....| Three applications, whitewash lime 2] 309 56] 254 12) -563 680 87590 serene ee 15 pounds to 50 gallons water: 3} 419 | 118] 136 18) 555: |)" 136) || 7o.40"|Pece ones Apr. 27; May § and 20. 4| 554 7 345 30; 899 109) 6875.87) | eee 5 548 78 250 9 798 | 87 | 89.09 |-------- a al 2,223 | 368 1,068} 69 3.291] 437 |......-. 36.72 | 1 374 1933) Se ca=||(SSas sc 374 108 Cll Seen | 2 243 64 | 336 22|| 57 865) © (85: 14 ee =e TL... | WU npreated)...2.-seeteeeem aes eee: 3 | 201 | PI Bees acioae 201 4) AGG) saeeeaee 4 440 140 118 ilit 558 151 M2 Ot ae ee ees 5 | 8380] 234 70 2: || 900.) "236" || aioatie| seeeeeee 12,088 | 593} 524] 35 [2,612 | 628 | pee 75.96 The curculio was not especially abundant in this orchard during 1906; as shown by the condition of the check, about 25 per cent of PLATE XVII. 5S . of Agriculture. gy, U. S. Dept omolog + t 103, Bureau of En Bul. aIL—'s e01L— & (‘[BUISII( Tal St 9) “prydins ormosre yyTAL “U9e15 SUB YEA o0U0 poAvads ood [ JO OPVUISIV [VLOIOULULOD YIM VoUO posvBids 901[—'Z “SI ‘d01} Yooyo 10 podAvAdsuy—'T “Sly “pee VA ‘WYHV4 NOLONITYY ‘ aovino4 a0u0 podwids 901,.—'9 “SI “plouaesie ude YIM 90U0 podABIds L— Pb Sl“ pBey] JO 9} BUdSIB OpRUTOUIOY YL BDU poABIds HOVAd NO SAVUd§ IVOINASYY JO 1044494 Bul. 103, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XVIII. Fic. 1.—ELBERTA PEACH SPRAYED THREE TIMES WITH ARSENATE OF LEAD, SHOWING BURNING AND CRACKING EFFECTS OF THE POISON. (ORIGINAL.) Fia. 2.—JAPANESE PLUMS, SHOWING BURNING FROM ONE APPLICATION OF ARSENATE OF LEAD. (ORIGINAL.) ARSENICAL INJURY TO FRUIT SPRAYING PEACHES WITH ARSENICALS. 909 the fruit was infested. Nevertheless, the results show a certain benefit, there being a gain in uninjured fruit on the plat treated with arsenate of lead of 20.63 per cent, and on Plat II, treated with lime, of 10.76 per cent. Results obtained also in 1906 at Myrtle, Ga., are shown in Table CIII. The trees treated were located in an 8-acre block of the Georgia Belle variety, composing a 200-acre orchard. The treated area, however, was on one side of the orchard and fairly well separated from the main body of the trees. Conditions for the curculio were here ideal on account of adjacent woods, and the presence here and there through the orchard of terraces which had become overgrown with bushes, weeds, etc. Each plat comprised 50 trees. The dates and character of applications are shown in the table, as well as the number of trees on which records were taken. The average percentage of sound fruit on the untreated trees was 67.59 per cent. As compared with this injury there is a gain in sound fruit on Plat I, sprayed with arsenate of lead, of 21.04 per cent, and on Plat I, sprayed with lime, of 2.20 per cent. Results of spraying peaches at Mayfield, Ga., for the curculio in 1908 are shown in Table CIV. This work was carried out by the office of the Georgia State entomologist according to a plan furnished by this bureau. Each plat contained 60 trees of the Elberta variety, and while a sufficient number of trees was not used for making counts of the fruit, the results are nevertheless significant. TasLe CIII.—Results of spraying Georgia Belle peaches for the plum curculio, Myrtle, Ga., 1906. Fruit from | Fruit from Total Aver- ground. tree. Total ae pees iss ve. Treatment. Ne. per of| fruits | #82,0f| eomt 7 In- .){ In- |fruits.| in- : Total.) rocteq.|POtal-| tested. fested,| {ruit. [souee | ruit Gg bae: AaetS ori) Oh. ‘si 2 28 6 171 4 199 10 3 47 7 144 4 191 ala 4 39 13 135 9 174 22 1 ee Three applications homemade ar- 5 33 10} 180 5 213 15 senate of lead 2 pounds to 50 6 10 4]. 81 5 91 9 gallons of water plus 3 pounds ii 38 22 | 2138 8 251 30 stone lime: Apr. 10, 21, and 30. 8| 14 3 80 5 94 8 9| 42 16 | 266 16 308 32 10 23 me 92 15 115 26 11 14 4 48 7 62 11 12 27 14 134 8 161 22 333 114 |1, 665 113 | 1,998 227 1 2 1 24 2 26 3 2 10 4 32 12 42 16 3 66 10 77 9 143 19 4 10 6 29 3 39 9 Il....| Three applications of whitewash, 5 33 20 69 16 102 36 15 pounds lime to 50 gallons 6 17 4 59 13 76 17 water (no arsenical): Apr. 3, 13, 7 28 16 63 23 91 39 and 21. 8 27 15 | 144 35 171 50 9 22 12 46 9 68 21 10 7 1 16 6 23 7 11 27 13 31 18 58 31 12 50 37 220 0 270 87 299 139 810 196 | 1,109 BELTS Bese eee 69.7 r i | 17262°—Bull. 103—1 2——14 210 THE PLUM CURCULIO. Tasie CIII.—Results of spraying Georgia Belle peaches for the Ben curculio, Myrtle, Ga., 1906—Continued. Fruit from | Fruit from Aver- ds. tree. Total grounds ree | Total | num Per ae Plat Treatment. Tree nur- | ber of age of | cent- No. No. | ber of | fruits rotat.| 28-, /rotas.|. 2m, |#ruits.|_in-_ | fruit: | bend ested fested fested = fruit 1 34 14 42 18 76 2 29 22 25 17 54 3 70 33 185 28 255 4 69 33 224 52 293 5 81 48 187 48 268 6 28 16 98 26 126 T= 22) Unireated sascccc cemensscoseicece 7 18 14 46 17 64 8 14 11 75 20 89 9 22 12 58 14 80 10 16 6 80 6 96 11 21 18 29 7 50 12 17 9 75 11 92 419 236 sama 264 | 1,543 TaBLe CIV.—Results of spraying Elberta peaches for the plum curculio, Mayfield, Ga., 1908. Fruit from | Fruit from Aver- ground. tree. Total | per. | age Total | num- | cont. per- Plat Treatment. Tree |—__7__|—_,_| num- | ber of) aoe of | cent- No. No. 2 . per of | fruits | ound age of n- n- | fruits.) in- : Total.) rested.) TOt@l-| tested. fested,| fruit. sound | eee Four applications, 2 pounds arsenate of lead plus 3 pounds lee naan 137 aoe BN Sse |e A : 2 100 11 110 32 210 BPR ee Beoscsa stone lime per 50 gallons of wa- 31 194 19| 43 197 631 146 | 76.86 ter: Apr. 2, 11, 17, and 25. ie (Mees) (Nees | [De pinks feedar'tam [ROSES 450| 44] 883| 296] 1,333| 340 |......- 74.41 II....| Three applications, 2 pounds 1 98 12.) 322 137 420 149 | 64.52 |...--.. arsenate of lead plus 3 pounds 2| 188 9] 213 107 301 1163) (GL46) Ee scaee stone lime per 50 gallons of wa- 3 | 228 18 | 361 140 589 atte) Pb bets) |e eosane ter: Apr. 2, 11, and 17. 4{ 296 34) 331 154 627 188 | 70.02 |...-.-- 810 73 {1,227 538 | 2,037 GIS |eceeeee 70. 00 III...| Two applications, 2 pounds ar- 1| 136 464 184 97 320 143° || 55.31 | so. scs~ senate of lead plus 3 pounds 2| 135 16 || 299 38 434 ty itsy Gud) eee stone lime per 5C gallons water: 3 | 163 26 | 336 132 499 158 | 68534 | bee eerre Apr. 2 and 11. 4 61 3 145 45 206 4B) (76,707). 2 occ. 495 91} 964 312 | 1,459 403 |....---| 72.30 W 119 87 75 64 194 5D) 2c Mell emtcerte 2 86 59 10 9 96 GSP ZOU Eee sats TVe--| Untreated ooanseunrcee cess eeecese 3 133 39 ; 278 197 411 236 | 42.58 |...---< 4 85 61 125 122 210 133") 12786) eerie 5 134 82 143 126 277 208:|, 24.91 [22.2.2 557 328 | 631 518 | 1,188 $46) | Goes 28.78 It will be noticed that on the unsprayed block only 28.78 per cent of the fruit was uninfested. Plat I, which received 4 applications of arsenate of lead, shows a gain in sound fruit of 45.63 per cent. Plat II, which received 3 applications, of 41.22 per cent, and Plat III, receiving 2 applications, a gain of 43.52 per cent. According to the notes accompanying this experiment very serious injury followed the SPRAYING PEACHES WITH ARSENICALS. AL 4 applications given Plat I, and the injury to Plat IIT was also so severe as to render unsafe such a number of applications. Table CV gives results of spraying Elberta peaches for the curculio at Baldwin, Ga., in 1910. (See Pl. XIX.) These plats contained some 200 trees each and counts were made of fruit produced through- out the season on 12 trees from each plat. Two applications of arsenate of lead were made, the first in water and the second in the self-boiled lime-sulphur wash (see p. 212). At the time of the first application, April 7-8, the blossoms of the trees had just fallen. The unsprayed block (Plat IL) yielded 56.85 per cent of sound fruit as compared with 89.85 per cent of sound fruit from the sprayed block, a gain of 33 per cent. Taste CV.—Results of spraying Elberta peaches for the plum curculio, Baldwin, Ga., 1910. Fruit f Fruit fi | ruit from ruit from Aver- ground. tree. Total) per | age Total | num-| cont. per- Plat Treatment. ‘LICC| aes enlleesaal ane te ber of | age of| cent- No. No. : ; Ber of | fruits | sound | age of n- n- |fruits.| in- | : Total.| tested.|TOtl-| tested. fested,) uit. pian 1 447 7} 589 26 | 1,036 Ban | LOOs ole mete ciscis Z 119 8 | 465 45 584 53 | 90:92) |--2--=2 d Laer First application Apr. 7-8, ar- 3} 177 10] 388 65 565 TO) SOnterlesssace senate of lead 2 pounds to 50 4] 363 24 | 606 76 969 1OO)} 88563) |2o-2--= gallons water; second applica- 5 | 161 10 | 335 61 496 CAP eG eens tion, 2 pounds arsenate lead in 6 96 12} 409 26 505 38 | 92.47 |......- self-boiled lime-sulphur wash 7 99 2] 358 38 457 AQ} /91.:23 ||. 525-8 (8-8-50), ae 27-28; third ap- 8} 222 22 | 293 33 515 59;,| 89.32 |2.-25-2 plication, lime-sulphur wash 9 | 702 25 | 412 123 | 1,114 LARS BGs Lelee es ae only (8-8-50), June 17-18. 10} 224 6| 476 83 | 700 Bo Levee) epesoe 11 68 7| 410 50 478 O70 |} 88.07 |esee see 12} 348 17 | 456 58 804 Wor O0L 6% eccees 3,026 150 (5, 197 684 | 8, 223 834, je2 sone 89. 85 Hale S80| liln |e ie 78h | Motes yn 2OR) | 4ori7 jena 2 187 83 | 385 132 572 2AS)| 62:40 Ef ses. 3 147 85 | 280 155 427 240 | 43.79 |. .--... 4] 839 114 | 648 239 | 1,487 BOS) Os 2Oi [sani ne, 4 ae ae ro 79 205 135) WS4e aoe sss. By) 47 189 | 1,076 304.) 64-10) [222 == bE SS eS S 7| 192| 71| 177| 94| '360) 165 | 55.28 |....... 8 | 318 55 | 299 147 617 202.) 67.26) |--2:..2 9 68 67 | 388 251 456 318 | 30.26 |....--- 10} 143 67 176 137 319 204 | 36.05 |....... 11 214 110 | 347 231 561 B40 39521) (eee 12 | 274 100 | 283 168 557 268 } 51.88 |....... | 3,251 | 1,088 |3,907 | 2,000 | 7,158 | 3,088 |....... 56. 85 The recent development, by Prof. W. M. Scott of the Bureau of Plant Industry of this department, of the self-boiled lime-sulphur wash as a fungicide for the control of brown rot and the scab of peach at once gave an enormous impetus to peach spraying. The desirability of combining arsenate of lead with the self-boiled lime- sulphur washed to many tests to determine its practicability. Such a combination, while resulting in important chemical changes, has in actual practice resulted in a spray which appears to be perfectly safe to peach foliage and fruit. Experience during the past 3 years 212 THE PLUM CURCULIO. with this combined spray on peaches under varying climatic condi- tions seems to leave no doubt that by this combination the injurious properties of the arsenate of lead, as when used alone, are so reduced as to be practically negligible. This probably results from the ex- cess of lime in the self-boiled wash. In Circular 120 of this bureau, published in the spring of 1910, a schedule of applications for this combined spray was given, including 2 applications of arsenate of lead with an additional one of the lime-sulphur wash alone. This schedule was followed by many orchardists in the South and a large ageregate of trees was thus treated. The results have been uni- formly satisfactory, so far as controlling the curculio and the diseases are concerned, and without noticeable injury to the foliage and fruit above referred to. It may therefore be assumed that a satisfactory combined spray for the insect and the brown rot and scab of the peach has been established, as has so long been in use on other deciduous fruits. Results of further experiments with this combined spray for the curculio, brown rot, and scab during 1910 have been given in Far- mers’ Bulletin 440, fully confirming previous results as to its great usefulness for the practical control of these three troubles. It is practically certain that its use will be equally effective in preventing losses to other stone fruits, as plums, cherries, apricots, etc. Direc- tions for making the self-boiled lime-sulphur wash and arsenate of lead spray, with a schedule of treatments for peaches, are quoted from the bulletin above referred to. DIRECTIONS FOR THE PREPARATION OF SELF-BOILED LIME-SULPHUR WASH. The standard self-boiled lime-sulphur mixture is composed of 8 pounds of fresh stone lime and 8 pounds of sulphur to 50 gallons of water. In mild cases of brown rot and scab a weaker mixture con- taining 6 pounds of each ingredient to 50 gallons of water may be used with satisfactory results. The materials cost so little, how- ever, that one should not economize in this direction where a valu- able fruit crop is at stake. Any finely powdered sulphur (flowers, flour, or ‘commercial ground” sulphur) may be used in the prepa- ration of the mixture. In order to secure the best action from the lime, the mixture should be prepared in rather large quantities, at least enough for 200 gal- lons of spray, using 32 pounds of lime and 32 pounds of sulphur. The lime should be placed in a barrel and enough water (about 6 gallons) poured on to almost cover it. As soon as the lime begins to slake the sulphur should be added, after first running it through a sieve to break up the lumps, if any are present. The mixture should be constantly stirred and more water (3 or 4 gallons) added Bul. 103, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XIX. Fic. 1.—GASOLINE POWER OUTFIT IN OPERATION. (ORIGINAL.) ee tee 2, - * Lesage ee a Ae Fic. 2.—DETERMINING RESULTS OF SPRAYING, EACH PEACH BEING CUT OPEN. (ORIGINAL.) FIELD EXPERIMENTS IN GEORGIA FOR CONTROL OF PLUM CURCULIO AND PEACH DISEASES. SPRAYING PEAGHES WITH ARSENICALS. 213 as needed to form at first a thick paste and then gradually a thin paste. The lime will supply enough heat to boil the mixture sey- eral minutes. As soon as it is well slaked water should be added to cool the mixture and prevent further cooking. It is then ready to be strained into the spray tank, diluted, and applied. The stage at which cold water should be poured on to stop the cooking varies with different limes. Some limes are so sluggish in slaking that it is difficult to obtain enough heat from them to cook the mixture at all, while other limes become intensely hot on slaking, and care must be taken not to allow the boiling to proceed too far. If the mixture is allowed to remain hot for 15 or 20 minutes after the slaking is completed, the sulphur gradually goes into solution, combining with the lime to form sulphids, which are injurious to peach foliage. It is therefore very important, especially with hot lime, to cool the mixture quickly by adding a few buckets of water as soon as the lumps of lime have slaked down. The intense heat, violent boiling, and constant stirring result in a uniform mixture of finely divided sulphur and lime, with only a very small percentage of the sulphur in solution. The mixture should be strained to take out the coarse particles of lime, but the sulphur should be carefully worked through the strainer. DIRECTIONS FOR USING ARSENATE OF LEAD. Many experiments have shown that well-made arsenate of lead is much the safest of all arsenicals at present available for use on the peach. Arsenate of lead is to be found on the market both as a powder and as a putty-like paste, which latter must be worked free in water before it is added to the lime-sulphur mixture. The paste form of the poison is largely used at the rate of about 2 pounds to each 50 gallons of the lime-sulphur wash and is added, after it has been well worked free in water, to the lime-sulphur spray previously prepared. As there are numerous brands of arsenate of lead upon the market, the grower should be careful to purchase from reliable firms. A decided change in color will result when the arsenate of lead is added to the lime-sulphur mixture, due to certain chemical changes which, in the experience of the writers, do not injuriously affect the fungi- cidal and insecticidal properties of the spray or result in important injury to the foliage. In large spraying operations it will be more convenient to prepare in advance a stock mixture of arsenate of lead, as follows: Place 100 pounds of arsenate of lead in a barrel, with sufficient water to work into a thin paste, diluting finally with water to exactly 25 gallons. When thoroughly stirred, each gallon of the stock solution will thus contain 4 pounds of arsenate of lead, the amount necessary for 100 914 THE PLUM CURCULIO. gallons of spray. In smaller spraying operations the proper quantity of arsenate of lead may be weighed out as needed, and thinned with water. In all cases the arsenate of lead solution should be strained before or as it is poured into the spray tank. The necessary care should be exercised to keep the poison out of the reach of domestic and other animals. Powdered arsenate of lead is used at about one- half the strength of the paste form. SCHEDULE OF APPLICATIONS. Most of the peach orchards in the eastern half of the United States should be given the combined treatment for brown-rot, scab, and curculio. This is particularly true of the southern orchards, where all these troubles are prevalent. In some of the more northern orchards the curculio is not very troublesome, but as a rule it will probably pay to add the arsenate of lead in at least the first lime- sulphur application. The self-boiled lime-sulphur mixture referred to in the following outlines of treatment should be made of a strength of 8 pounds of lime and 8 pounds of sulphur to each 50 gallons of water, and the arsenate of lead should be used at the rate of 2° pounds to each 50 gallons of the mixture or of water. When the poison is used in water there should be added the milk of lime made from slaking 2 to 3 pounds of good stone lime. When used in the lme-sulphur mixture additional lime will not be necessary. Midseason varieties —The midseason varieties of peaches, such as Reeves, Belle, Early Crawford, Elberta, Late Crawford, Chairs, Fox, and Beers Smock, should be sprayed as follows: (1) With arsenate of lead alone, about 10 days after the petals fall (Pl. XX), or at the time the calyxes are shedding. (2) With self-boiled lime-sulphur and arsenate of lead, two weeks later, or four to five weeks after the petals have been shed. (3) With self-boiled lime-sulphur alone, four to five weeks before the fruit ripens. Late varieties —The Salway, Heath, Bilyeu, and varieties with a similar ripening period should be given the same treatment prescribed for midseason varieties, with an additional treatment of self-boiled lime-sulphur alone, to be applied three or four weeks after the second application. Early varieties —The Greensboro, Carman, Hiley, Mountain Rose, and varieties having the same ripening period should receive the first and second applications prescribed for midseason varieties. Where the curculio is not particularly bad, as in Connecticut, western New York, and Michigan, the first treatment, which is for this insect only, may be omitted. Also for numerous orchards throughout the Middle States where the insect, especially in the younger orchards, is not yet very troublesome, orchardists should —— Bul. 103, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XX. SIZE OF PEACHES AT TIME OF FIRST SPRAYING WITH ARSENATE OF LEAD, SHOWING ON THE LEFT THE EARLIEST AND ON THE RIGHT THE LATEST STAGES IN DE- VELOPMENT WHEN THIS TREATMENT SHOULD BE GIVEN. (ORIGINAL.) SPRAYING PLUMS AND CHERRIES. 215 use their judgment as to whether the first application may be safely omitted. Where peach scab is the chief trouble, and brown-rot and curculio are of only minor importance, as may be the case in some of the Allegheny Mountain districts, satisfactory results may be had from two applications, namely, the first with self-boiled lime-sulphur and arsenate of lead four to five weeks after the petals fall, and the second treatment of the above schedule with self-boiled lime-sulphur alone three to four weeks later. These two treatments, if thoroughly applied, will control the scab and brown-rot, especially on the early and midseason varieties, and will materially reduce curculio injuries. Even one application of the combined spray made about five weeks after the petals fall would pay well, although this is recommended only for conditions where it is not feasible to do more. SPRAYING PLUMS AND CHERRIES. The first important tests of arsenicals in the control of the curculio were made on plums and cherries. In 1887 Mr. W. B. Alwood, work- ing under the direction of the entomologist of this department, made some limited tests on the grounds of the Ohio Agricultural Experi- ment Station, spraying Green Gage plum trees with Paris green at the rate of 1 pound to 50 gallons of water. Fully 50 per cent of the foliage and much of the fruit fell from the trees as a result of the treatment. No definite conclusions were drawn from the experiment. May 17 of the same year 17 cherry trees were also sprayed with Paris green, 1 pound to 50 gallons of water, and the results in this instance also were not fully determined. During the same year Prof. A. J. Cook in Michigan sprayed 4 plum trees May 18 with Paris green at the rate of 1 tablespoonful to 6 gallons of water. “No trees were kept for comparison, and no definite conclusions were thus to be drawn. During 1888 Prof. H. Osborn, then an agent of the Division of Entomology, carried out in lowa some thorough spraying experiments, usi#® 11 plum trees of several varieties, leaving 10 trees unsprayed as a check. London purple was used at the rate of one-half pound to 100 gallons, applications being made June 1 and 11. Concerning results, Prof. Osborn states: Combining the entire count of all varieties, and we have for the sprayed trees a final of 32.48 per cent punctured, or stung, and 5.71 per cent containing larvee, against a final of 41.86 per cent stung and 10.39 per cent containing larvee for the check trees. During the same year Prof. Weed in Ohio began a series of tests of arsenicals on cherry and plum, which were continued during 1889 and 1890, during which latter year the work was carried out on a commercial basis in a plum orchard of 900 trees in the fruit districts along the south shore of Lake Erie. These careful experiments of Prof. Weed clearly showed that a considerable benefit from spraying was to be derived and were altogether the most extensive and com- plete heretofore presented. 216 THE PLUM CURCULIO. In Bulletin 9 of the Iowa Agricultural Experiment Station, page 383 (1890), Prof. Gillette gives results of experiments on plums with London purple on the plum curculio and plum gouger. The poison was applied with a hand pump to 23 trees at the rate of 1 pound to 120 gallons May 4 and 11. The leaves were badly burned. After May 25 all drop fruit on 5 trees each of the sprayed and unsprayed blocks was examined. A total of 21,000 plums was examined, and a benefit was determined of 1.1 per cent in favor of spraying. SOME RESULTS OF SPRAYING PLUMS. At Fort Valley, Ga., during 1905 Mr. Beattie carried out some spray- ing tests on Japanese plums. The plats were, however, small and there was considerable overflow from the surrounding unsprayed trees. Plats were laid off, extending across three varieties, namely, Wickson, Red June, and Satsuma, in which order the varieties are given in the table. The entire crop throughout the season from three trees of each variety was counted with the exception of Plat I, where only 2 trees were used. Plats received from 1 to 3 applications of arsenate of lead in water, without addition of lime. According to Mr. Beattie’s notes practically no injury resulted to the foliage from the sprays. The results are given in Table CVI. Taste CVI.—Results of spraying Japan plums for the plum curculio, Fort Valley, Ga., 1905. Fruit f 2 |9|5 | 3 & | & Oy Truit from tree. | 3 2 Wey lee s Pale! ground. m|2 . = RC Es al 2 iss g Om | oe 5 5 BS 3 os os Plat ~ j $3 15 la=| as |] 82 | og No Treatment. Pt sate Soi. Pas Ag) AS | Bg | &8 NO. 6/81 a | ss ETE cz | ane SA 4 S| So Pe) BS rh Soe (eee te ey aes ala 8/5181 eles! 2 12 {SSS ee Sa Sree acl ahs. | telsea le oatll ce eaee |p > SH ® HIAI/A INIA I|Aa |e] a = H = is < Ay Tee One application, ar- senate of lead, 2 1) 52) 44 2| 54) 152) 37] 26 178 204; 81} 28 232|'4 35 oca| sone pounds to 50 gal- 2| 236] 213) 114) 350) 60 4! 300} 360) 296) 217) 414 PLO sees | See lons water, Mar. 19. 288] 257) 116] 404) 212] 41] 326) 538) 500) 298} 442) 942) 46.92) 39.41 II....| Two applications ar- senate of lead, 2 ounds to 50 gal- ons water, Mar. 19 and Apr. 20. 255| 211) 71} 326) 430) 28) 527) 957) 685] 239) 598) 1, 283)..._.- : 38] 410) 31) 11] 35 66) 403) 356) 73) 476)......|...... 210} 172| 32] 242) 73) 15) 200) 273) 283] 187] 232) 515)......)...... whore wo =] i) BG rag or ie) 2) 837] 728] 141) 978} 534) 54) 762) 1,296} 1,371 88] 69; 72] 160] 90} 25; 270) 360) 178 8 218} 90) 30) 194) 284) 243 108] 92} 53] 161) 72) 8/ 313) 385) 180 arsenate of lead, 2 | pounds to 50 gal- | lons water, Apr. 4 and 20, May 4. whore = or mw ee iS) 2) > ou TII...| Three applications | 349] 299] 190} 539} 252) 63) 777) 1,029) 601 6s 45| 31| 991 40/ 9| 35| 75] 108 135| 105] 17} 91/ 196| 210 72| 58; 10 s2| 11s| 36/ 6) 124| 190 IV. .=|) Umsprayed:. =... |< Whe — S Rik i?) x wo i=) 245| 190} 71) 316; 263} 62/ 132; 395) 508 SPRAYING PLUMS AND CHERRIES. 217 Curculio injury on all of the plats was severe. On the check there was only 28.55 per cent of fruit free from punctures and infestation. On the plat sprayed 3 times, 61.67 per cent of the plums were sound, a gain in sound fruit over the check of 33.12 per cent. Two applica- tions gave a gain of 11.15 per cent and the single treatment showed an increase over the check of 18.37 per cent, a difference doubtless due to location. A more exact idea of the commercial benefits of spraying, however, may be had by a consideration of the relative amount of ripe fruit at picking time showing the punctures of the insect, as being more or less deformed and unsalable, for it will be understood that not all ripe fruit showing punctures is unsalable. On the check plat (IV) of the ripe fruit at picking time 66.58 per cent were punctured, as against 24.48 per cent on Plat II, receiving 3 applications. Plats I and II show about the same amount of punc- turing on the ripe fruit, namely, 39.41 and 41.20 per cent, respectively. During 1906, at North East, Pa., an orchard of about two hundred 16-year old plum (York State prune) trees were sprayed by Mr. Johnson, using Bordeaux mixture plus 3 pounds arsenate of lead. Through an error only one tree was left unsprayed for comparison. All of the fruit throughout the season was carefully examined from this tree and an adjacent unsprayed tree, and the results are shown in Table CVII. Previous to this season the owner had followed the jarring method, but by reason of the favorable results spraying was subsequently followed. This same orchard was sprayed during the following year by Mr. Johnson, and results taken on five sprayed and five unsprayed trees are shown also in the table. Tasir CVII.—Results of spraying York State prunes for the plum curculio during the seasons 1906 and 1907, North East, Pa. 1906. : : & ! ; Sis Fruit from ground. Fruit from tree. g ae a= 3 q 7 = feta oes |e Ho} ge ee ; = Ssolsd| uy | 2 s Trees. Treatment. + 5 | ® ; 2g &S q | Saat 5 Le! | Sic a = 4] ° = = sa s oe Se ea | cs! ie ical (eee 2 a | 5 2 q ra a | 2 q 3S 3 3 3 a s Be cee baal) | et Bear ho ee SiS he am ie n = | 73) a a a is = a 1 | Three treatments, 448} 393] 1,207) 1,655) 69) 0} 1,640) 1,709} 517; 393] 2,847] 3,364] 84.63 Bordeaux m i x- ture (44-50) plus 3 pounds arsenate of lead: May 25, June 7 and 19. One untreated..... 1,621/1, 446} 532] 2,153) 272) 0; 470] 742) 1,893) 1,446} 1,002) 2,895) 34.61 | 5 | Twoapplications,}] 435) 344) 6,933] 7,368) 14 0 9, 559] 9,573 449 344/16, 492.16, 941) 97.35 Bordeaux mix- ture (44-50) plus 3 pounds arsenate of lead: June 8 and July 3. Five untreated... .- 581; 490; 7,481) 8,062) 57 0} 8, 153} 8,210 638 490/15, 634 16,272) 96.08 | 918 THE PLUM CURCULIO. During 1906 there was a gain in sound fruit on the sprayed trees of 50.02 per cent as compared with the check of 50.01 per cent. The difference the following year, however, was small, 1.27 per cent, as the insects were comparatively scarce, no doubt following their practical extermination in the orchard the year previous. Extensive plum-spraying experiments were begun at Barnesville, Ga., in 1910. The work, however, was stopped by the loss of practi- cally all of the fruit from the effects of a heavy wind storm. RESULTS OF SPRAYING CHERRIES. A block of Montmorency cherry trees at North East, Pa., was sprayed June 11 with 3 pounds of arsenate of lead to 50 gallons of water plus 3 pounds of stone lime. Another block received an addi- tional application June 25, while a third block (4 rows through center of orchard) was left unsprayed. When fruit was gathered, July 18, three trees on the first-mentioned plat gave a total of 16 wormy cherries and 434 pounds of sound fruit. The same number of trees on the second block, having 2 applications, gave 10 wormy cherries and 53 pounds of sound fruit. The 3 trees on the check plat gave 74 wormy cherries and only 16 pounds of sound fruit. The trees were chosen as nearly alike as possible and the results may thus be fairly compared. As compared with the check, the plat treated twice shows an increase in sound fruit of 37 pounds and from the plat sprayed once a gain of 27.5 pounds. More data are needed to show the protection from curculio which will follow spraying plums and cherries, though this will without doubt be quite as marked as with peaches. The same spraying schedule indicated for early peaches will be suitable for plums and cherries, and the arsenical should be used in the self-boiled lime- sulphur wash. ECONOMIC BIBLIOGRAPHY. 1736-7. CottInson AND Bartram.—Darlington’s Memorials of Bartram and Mar- 1749. 1802. 1804. 1806. 1807. 1807. 1815. 1819. 1819. 1822. shall, p. 85. Remedy for insect that annoys plums, apricots, and nectarines. Id.—p. 93. An account of the destruction by an insect of plums and nectarines. Id.—p. 120. Advice against the planting of sloes, as they are “liable to be bitten with the same insect as the rest of our stone fruits.” Katm, Perer.—Travels into North America. eee ae eee 29 Barium’ carbonate against plum ‘cureulio. 72---.-. 2. eee eee 206 sulphid against plum curculio.. 2. o>, 2242-2. 5335-08 ee eee 206 Birds, enemies of plum curculio: - 222.2... -2. 252. a.e89 eee 154 Black knot, breeding place of plum curculio....- 2.22.4 + - 545 =e eee 33 of cherry and plum, use for egg laying and food purposes by plum CUPCULIO 2 a. 2. . 2 et ene eee 132-134 MaMes, COMMON....22 oso. sae so ee ee ee 14-15 INDEX. 249 Page. Plum curculio, natural enemies. ....----- RRR Seite sae a= 2 = eins 139-154 occurrence of beetles in orchards.....------------+--------- 120-125 parasitic enemies... -+-=-- ss. 0-22-92 - 2-9 = "== 6227 o een 140-152 percentage of fruit punctured or Mnestcdne sees. es 2... 134-138 predaceous insect enemies.......-----+----++225rrrtrrrrte 152-154 pups, Cescription. .24---0--= sass 32 length of stage and time spent in soil, before and after MUPRUION +. 2a eae Ren a ere ee me ee mies 83-87 time spent in SOll.J+-iec-s ee esa eh @ reg r 73-83 pup, cultivation for deniricuOletee serene e eee = = 176-178 pupal cell; depth. 2:---..2:<- 3-252 042 e-em nen 87-88 remedial measures.......-.--------22-ee cece eee n eter 155-218 likin lites ee noocooeodbocepe codeseuane 155-167 remedies, cultivation for destruction of pupe...------------- 176-178 Janrne. ic. ee see ee eee eco Sepa 168-176 feeding experiments with poisons.....------------ 185-189 premiums therefor....-------------+-++-++--+++-+-> 167-168 Ransom chip process....--------------++-+++-+--7- 168 spraying with arsenicals........------------------ 178-185 PAO RINE ISCO Etre a neriee oe eee em set = in in inn m2 2 = 3 112-134 spraying scheme for apple orchards...-------------+--++++++>- 201 of apple at Anderson, Mo....-.-----------------+- 193-194 StyJdoseph, Mo. 2.2.52. .2f-2-2------+- 198-199 Siloam Springs, Ark....------------------ 196 CONCIUSIONS. 2 ooh ee aes as aes tease = = 200-201 early experiments.......-------------+--+-- 189-193 experiments by Bureau of Entomology... - 193-200 TN i 07 1 yaa oe eae SE 197-198 western New York and _ northwestern Pennsylvania......-----------+-------- 195 peaches with arsenicals. ....-..-.-------------- 202-215 plums and cherries. ...-.-.----------+--+------ 215-218 Ay MOMpAR Yeas nooo 8 ene e ane ae cine ens ere eS Cr 13-14 time for transformation from egg to adult......------------- 110-112 of appearance of beetles in spring..--.---------------- 112-120 spent in fruit, egg and larval stages combined..-..------ 65-73 transformations in ground, effect of soil conditions thereon... - 88-92 food plant of plum eurculio.°5-----2--- === = -2)--== 2-25-22 eee es 33 gouger. (See Anthonomus scutellaris.) moth, so-called. (See Enarmonia prunivora.) order of preference in oviposition by plum curculio....----------------- 33 weevil, common name for plum CULCIIINO Ee Se ete ee cae est ei 14 Plums, cultivated, variation in susceptibility to plum curculio......-.-------- 34-36 Poisons (sce also Arsenicals, etc.). against plum curculio, feeding experiments. ....------------------ 185, 189 Porizon conotracheli. (See Thersilochus conotracheli.) Potato-stalk weevil. (See Trichobaris trinotata.) Premiums for remedies for plum curculio.....----------------+++--+++-++--7+ 167-168 Prunus americana, food plant of plum curculio. ..----------------------++++- 36 angustifolia, food plant of plum curculio -...----.--------+--++++++++ 36 domestica, food plant of plum curculio......-.---------------++-+++-- 36 hortulana, food plant of plum curculio.....-.---------+------+++5+000> 36 simonii, apparently not injured by plum curculio....-.----------+++-- 35 250 THE PLUM CURCULIO. Page Prunus triflora, food plant of plum curculio.....-....-5-22.2-2 e==see-eEeeeee 35 umbellata, food plant of plum curculig. . 2oee- ao-e eee eee 36 Quinee, food plant of plum curculio.....-.. 2222222 9eecss ease eee eee 33 order of preference in oviposition by plum curculio..........-....-.--- 33 Ransom chip process against plum curculio_.-. =2.5- ds-25; ese eee ee ee 168 Rhynchenus argula=Conotrachelus nenwphar.--2-- - see >eeue eaaeeee eee 14 cerdsi= Conotrachelus Renuphan -.2a>->222-- > - Reese 2 225 --e eeee 14, 16 Riparia riparia, enemy of plum curculio..............--.--<----- Cn ee 154 Rose-beetle, Fuller’s. (See Aramigus fulleri.) Sigalphus curculionis. (See Triaspis curculionis.) Snout-beetle, imbricated. (See Hpicerus imbricatus.) Soda, sulpho-arsenate, against plim curculio:-222. 4-2-2) 2... 20 eee ee 188 Ghupenches, ........: 2.5 206 and self-boiled lime-sulphur against plum curculio. - . - - 188 injurious effects on peach\; =: sseeee 2. eee 207 Sphenophorus parvulus, host of Myiophasia xnea........-..-------------+----- 149 Spraying with arsenicals against plum curculio.................-...-..----- 178-185 on apple, early experiments. 189-193 experiments by Bu- reau of Entomolo- BYicotn es oct oe 193-200 cherries and plums.....-.- 215-218 peachess es =. Sse cr eee 202-215 Strawberry, place of oviposition by plum curculio..........--..---.--------- 33 Swallow, bank. (See Riparia riparia.) Temperature, relation to time of appearance of plum curculio in spring. .... 118-120 ‘Tent: caterpillar, spraying with, arsemicals:..sc.s-c 05: 225-2) a eee 201 Mhelavrodes basalis— Cholomipqginequipesssseseee sa ae eee eee eee 150 Thersilochus conotracheli, parasite of plum curculio............------------- 147-148 Thrips, enemy of plum curculio. . : Jee edS Sees eee aeee ee Thrush, hermit. (See Hylocichla eaten _ Tmetocera ocellana. (See Bud moth.) Tead. enemy of plum curculio.2- 25352. oes. o re oe oon eee ee 154 Triaspis curculionis, parasite of Anthonomus grandis ......-......-..---------- 143 Balanvaus Spice ee 35 ee 143 Conotracheliis Gjinis. 24... eee eae ee 143 Clegans 52 i203 Ae oe eee 143 juglandigs 3:5: 2.50 3% See eee 143 plum ‘curenlio;26220.35.. ose eee 142-146 stalk-borer on Aimbrosia......42<-,2s4:522e5 see 143 Trichobarts trinotaitxe sens =-t2- aoe hee eee 143 var. rufus, parasite of plum curculio.......-...---.---- 146-147 Trchobaris trinotata, host of: Tmaspis cureulionis..2-2ccs2- see ee 143 on eorplante os. 2s. 325 2 se eee eee ee eee 143 “Turk,” common name for plum cureulie....2 sees see ep See 14 Veery. (See Hylocichla fuscescens.) Vireo, yellow-throated. (See Lanivireo flavifrons.) Zamelodia ludoviciana, enemy of plum curculio..........-...-...------------- 154 Zinc cyanid against plumeureilio.-...222. ee. 4-45 oe ee eee 206 oxid against plum curculio.....22. 35.42.2558 Sone ee ee 206 sulphid, injurious effects on peach... 2225. A255 Jose2 22 2 eee 207 U.S. DEPARTMENT OF AGRICULTURE, | BUREAU. OF ENTOMOLOGY—BULLETIN No. 104. of L. O. HOWARD, Entomologist and Chief of Bureau. Re THE FIG. MOTH. F. H. CHITTENDEN, Sc. D., In Charge of Truck Crop and Stored Product Insect Investigations. REPORT ON THE FIG MOTH IN SMYRNA. E.G“ SMYTH, Entomological Assistant. x Issurp November 4, 1911. WASHINGTON: ~ GOVERNMENT PRINTING OFFICE. r 1911. Bul. 104, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE l. Fic. 1.—SMYRNA FIG FROM NEW YoRK City, SHOWING INJURY BY FIG MOTH (EPHESTIA CAUTELLA). (ORIGINAL.) Fic. 2.—DRIED Fias INFESTED WITH FIG-MOTH LARV4, SHOWING HOLES BORED THROUGH SKINS, ABUNDANT EXCRETA ADHERING TO FIGS, AND SINGLE LARVA AT RIGHT. (ORIGINAL.) Us. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN No. 104. L. O. HOWARD, Entomologist and Chief of Bureau. ELE FG Oey F. H. CHITTENDEN, Sc. D., In Charge of Truck Crop and Stored Product Insect Investigations. REPORT ON THE FIG MOTH IN SMYRNA. E. G. SMYTH, Entomological Assistant. IssuED NovEMBER 4, 1911. THE po 2 aN ean SS IIssssS> WASHINGTON: GOVERNMENT PRINTING OFFIOE. 1911. BUREAU OF ENTOMOLOGY. L. O. Howarp, Entomologist and Chief of Bureau. C. L. Martatr, Entomologist and Acting Chief in Absence of Chief. R. 8S. Ciirton, Hxrecutive Assistant. W. F. Tastet, Chief Clerk. I’. H. CHITTENDEN, in-charge of truck crop and stored product insect investigations. A. D. HopKIns, in charge of forest insect investigations. W. D. Hunter, in charge of southern field crop insect investigations. I. M. WEBSTER, in charge of cereal and forage insect investigations. A. L. QUAINTANCE, in charge of deciduous fruit insect investigations. HK. F. Puivuies, in charge of bee culture. D. M. Rogers, in charge of preventing spread of moths, field work. Rota P. Currige, in charge of editorial work. MapBet Coxcorn, in charge of library. ; TrucK CROP AND STORED PRODUCT INSECT INVESTIGATIONS. IF. H. CHITTENDEN, in charge. H. M. RUSSELL, C. H. PoPENOE, @V™M. B. PARKER, H. O. Marsu, HE. G. Smytu,® Tuos. H. Jones, M. M. Hicu, Frep A. JoHNSTON, entomological assistants. I. J. Conpit, collaborator in California. P. T. Coir, collaborator in tidewater Virginia, W. N. Orb, collaborator in Oregon. Marion T. VAN Horn, preparator. «Transferred to cereal and forage insect investigations, Mar. 15, 1911. 2 LETTER OF TRANSMITTAL. Untrep States DEPARTMENT OF AGRICULTURE, Bureau or Enromo.oey, Washington, D. C., August 2, 1911. Sir: I have the honor to transmit herewith the manuscript of a bulletin dealing with the fig moth. It consists of two papers, the first, entitled “The Fig Moth,” by Dr. F. H. Chittenden, in charge of truck-crop and stored-product insect investigations, and the sec- ond, entitled “ Report on the Fig Moth in Smyrna,” by Mr. E. G. Smyth, entomological assistant. While the fig moth has been known in this country as a pest since 1897, at which time a short preliminary paper was published in regard to it in Bulletin No. 8, new series, of this bureau, it was not until 1908 that the insect attracted any great attention. It had by that time invaded mills of various kinds, including rice mills in the Southern States, and in these situations it is now quite a serious pest. In 1909 and 1910 thousands of dollars worth of figs were condemned by the Bureau of Chemistry under the law regulating the sale of adulterated or deleterious foods and drugs. This led the importers and dealers in Smyrna figs to request an investigation of the matter by the United States Department of Agriculture. In pursuance of your directions Mr. E. G. Smyth visited Smyrna in Asia Minor to investigate the local conditions under which this important industry is carried on, and his report is embodied in the second paper of this bulletin. The work upon which the first paper is based was conducted by Dr. Chittenden in person, and this portion of the bulletin gives a very full general account of the insect. The life history and food habits of the fig moth, as it occurs in the District of Columbia, where the weather in midsummer is not ma- terially cooler than in Smyrna, have been thoroughly worked out, while the recommendations as to remedies are based upon actual experiments. Particularly valuable among the remedies suggested would be the treatment of figs in specially prepared fumigatories located a short distance from the “ khans” or buildings in which the figs are stored. 3 4 LETTER OF TRANSMITTAL. It has been tound that bisulphid of carbon in a high temperature, ranging between 90° F. and 100° F., will kill practically all fig moths with an exposure of 24 hours, even with less of the fumigant than is usually advised. I recommend the publication of these papers as Bulletin No. 104 of the Bureau of Entomology at the earliest possible moment, since there is urgent demand for this information on the part of merchants and growers interested in the culture, shipment, and sale of Smyrna figs. Respectfully, L. O. Howarp, ~ Chief of Bureau. Hon. James WILson, Secretary of Agriculture. CONC Ban oe Page. The fig moth (Ephestia cautella Walk.)................---- F. H. Chittenden. . 9 PMR HIRT Seer 2 heh AS a2 ae eek Seat Bo gee Sores Salcedo 9 IB eaerip Mitt Gh the, SPOCled: i024) st dus hen eiieeds ateuee aes meee: ee Alen 10 Whoraciers Gr ine moth. ..ati<..) «220i, ds6'st ead eee. Op Meee 10 Technical description of the moth... ¢: 2... = j.tieeh ee sax eee 11 PRY ON 8 aoe oa ci nc on oe sis oe ORE eee ER eee eae eae f 11 MearEp non of Thereariicr stares: 2.6. 200 Shwe o-\ as ke ew Soe SR 11 PRO r see Me etary 3 pets oS eee a, < ih ta chee tons Sn iA Rs as uu iWhemewly hatched: larva. . 3255 254 SS gi Wee eet cae hen ete 12 pbc mua -orawyals lott Al re Pee ae te oe thie ideas a o> 12 Meieocoan and olla: S258 oe see SE ere Sa keh a tn eee oes 13 Literature and history of the species in Europe...............------------ 13 History of the spectes\in America-..--...----------:------ ett Ie ore 14 LAE SUI SUITE 2rc 2 MO aa SH a Ro ee Oe ee ee 19 Inspection of Smyrna figs in the Bureau of Entomology.............--.-- 21 Inspection of samples of figs from the Dried Fruit Association. .........-- 25 Average infestation of figs entering the port of New York.................. 28 Time -banconymotes oni tlie fie: moth. 2 26-4 s2-wece - Scedo ie eee ieee lee ee 28 Maal pRERUSTIe Me Ae eee cates oa ve SES ae ite PS ay Sas Moen ve ek bo 28 PR cHelaniniOrMmarion TOmMpas. 22 cease Soe = ction sk eee ee Se oo: 29 ASUS EIEN 0) CF ee eS = i ace et ee 29 (SP URS SCTE Boss I |e ee 30 OSES CQ SACL SULTS DRS OS eo = ete e 32 CEILS ge oe a ee ee eee et ae a - aes 33 Pele pra LEUNCOR cern a Seat eh. ae eS het OR oe cid fale Rea a ote 34 Methods of packing figs as a protection against insect attack........_. 35 Experiments with fumigants at a high temperature...............-.-- 36 Peery iene GHRDOM ets Pants al Sena. . ae bas +5. 9 ee Destruction of eggs on! figs: .c- css ssces sone oo ee eee eee eee Discontinuing the retention’ of figs Inland. °-2.2....-5.5------2-osee== Elimination of larvee im the khans.. 227-222 220 sc So 92) eee oe ee Experimentain. the khanmss si: : (As ee ee ee Destruction of larve by vacuum treatment.............----.- Ridding figs of larvee by steam.ete.! oe? eee Scalding figs in hot water to kill larve................------- Apparatus for sterilizing with hot air...-..-.-.-.52.--..--.--- Success of hot-air treatment in killing larvee...-...--.-.----.-- Practicability of sterilizing all figs in Smyrna Summary of preventive measures Puate I. VIE. IX. XIII. AY. . Fig. 1.—Closed railroad car or ‘‘wagon,’ ILLUSTRATIONS. PLATES. Fig. 1—Smyrna fig from New York City, showing injury by the fig moth (Ephestia cautella). Fig. 2.—Dried figs infested by fig-moth Page. Pais eh eee i So nde kee tare Me aos Soe See Frontispiece. . Pile of figs in fig depot, one of the primary places of infestation... -- . Fig. 1.—Figs packed by string method. Fig. 2—Some of same figs HO MMustrate: Leutvall suMtestatd OM see ae eee ees ree oe eee . Package of Smyrna figs, packed in Turkey for American trade, accord- ine Uorlavernnethod< iesa-cuahot eee: alee do Sooke i See ae . Fig. 1.—Extensive fig orchards in valley of Caystrus River, Asia Minor. Fig. 2—Typical Smyrna fig orchard in Meander Valley, J NSE IN LUT ORR SSE OS ees teen JES Re SUR eons HLS ae APS eect . Fig. 1.—The crude form of ‘‘serghi” employed in most orchards for drying figs. Fig. 2—Near view of figs drying on “‘serghi,’’ Nazli, Fine ye VaR OT etaee® ge oe aa et Be cee cio ees we Sion aie ome e . Fig. 1.—‘‘Serghi” of reeds laid in long rows, used in large orchards. Fig. 2—Uruk girls spreading figs on ‘‘serghi” to dry, Tchifte Peaaeeamea YP AINOL see eter ee hes UU L. aki are ies Sic 3,2 Fig. 1—Team of water buffalo, with driver and Turkish cart, often used for carrying figs. Fig. 2.—Figs arriving at a ‘‘depot,’’ brought from orchard on horseback by peasant who grew them, Tchifte 1 OST SSG Galas BIS ea ate a ON a ee ee eae Fig. 1.—Figs of different grades being mixed in ‘“‘depot” of interior, and resacked for shipment to Smyrna. Fig. 2.—Camel caravan conveying figs from a ‘‘depot” to railroad station in interior of Asia (one a 2 Ca Ue ee eee ae ’ used in transporting figs from interior of Asia Minor to Smyrna. Fig. 2.—An indoor fig eRe SEU VieR ee ect creat acini olan wi clin tee ie aici =e aamate ws wale, . Fig. 1—Pile of refuse figs in a Smyrna “‘khan.’’ Fig. 2—Greek women grading the refuse figs in a Smyrna “‘khan”.........----- . Fig. 1—Large ‘‘paciale” of natural (dried) figs, ready to sack for export, in a fig ‘‘khan” in Smyrna. Fig. 2.—Natural (dried) figs Dem watered) and. Maxed ss ico. ton ls ce cee Uae eee eee Fig. 1—Thousands of bags of natural (dried) figs in a Smyrna “khan” for export to America. Fig. 2—Skeleton cases of Smyrna layer figs bound for America in hold of Mediterranean steamer at Genoa. Fig. 1—A hand vacuum machine for extracting air from jars of figs, and its operator. Fig. 2—Oven for sterilization of figs by dry . Fig. 1.—Steam disinfecting closet. Fig. 2.—Interior of steam disin- FOGG CLORODE t= oh Roe tone. Ui shee alk Rime Seis J oats 44 44 46 46 48 48 48 48 8 ILLUSTRATIONS. Puate XVI. Fig. 1.—Copper boilers and galvanized strainers used for steriliz- ing figs in a Smyrna “‘khan.’’ Fig. 2.—Interior of oven for dry- ing trays of figs which have been sterilized by boiling, used in 3 fie‘khan” in“ Smyma.. 2.22025 <5 ew. -ss ee eee eee TEXT FIGURES. Fic. 1. The fig moth (Ephestia cautella): Adult, larva, and details..........-. 2. The Mediterranean flour moth (pian bina: arya. coe ee 3. Hadrobracon hebetor, a parasite of the fig moth: Adult female aa antenna of male. a. ..j.5 fice ee ob cements oe ee 4. Omorga frumentaria, a parasite of the fig moth: Adult.2255.S. en cn oeeee Page. 56 10 10 31 31 ela Tere ey ee ea By,.b. E.. CHimtenDEN,. Sc. .Ds In Charge of Truck Crop and Stored Product Insect Investigations. INTRODUCTION. Prominent among the many species of insects which are being ‘constantly shipped to this country from abroad is the fig moth (EL phestia cautella Walk.). Since 1908 this species has attracted much attention by its occurrence in various edibles in different por- tions of the United States, as well as in the mills of Texas and Louisi- ena. It has been concerned, with other insects, in considerable dam- age to rice, and reports are available of similar injury to flour and corn meal and other mill products, cotton seed, various other dried seeds and fruits, and other stored foods. In the late fall of the year 1909, however, the species attained unusual prominence from the fact fee the Bureau of Chemistry, working in pursuance of legislation on the pure food and drug law, seized numerous consignments and cargoes of figs in New York, Philadelphia, Boston, and some other large cities. This brought to light the fact that a very large portion of imported figs, especially such as are shipped from Smyrna, which port ships about 90 per cent of its total output to the United States, is found to be badly infested’ when reaching America. The dried figs in the market are frequently found to contain from 15 to 50 per cent and even higher percentages of infested fruit. These estimates, chiefly by the Bureau of Chem- istry, are based partly on the presence of the insect, but largely on that of its excreta. The gravity of the situation became such in 1909 and 1910 that thousands of dollars’ worth of figs were condemned, leading the dealers in Smyrna figs to request an investigation of the matter by the United States Department of Agriculture. In accordance with the Secretary’s direction, the following account of the fig moth has been drawn up, including a report, by Mr. E. G. Smyth, on the occurrence of. the insect in what is perhaps its native home—Smyrna, Turkey in Asia. The writer’s article deals pri- marily with the insect as a pest in stored products in America. 9 10 THE FIG MOTH. DESCRIPTION OF THE SPECIES. Before proceeding to the description of the fig moth it should be stated that according to recent classification it belongs to the lepidop- terous family Pyralide and subfamily Phycitine. Some writers give this subfamily full family rank and therefore call it Phycitide. As to nomenclature, the species 1s now recognized as E'phestia cautella Walk., with the following synonyms: cahiritella Zell., pas- sulella Barr., and desuetella Walk. CHARACTERS OF THE MOTH. This moth looks suspiciously lke the congeneric “’phestia kueh- niella Zell., the Mediterranean flour moth, and like /. elutella Hiibn., as will be noticed by reference to the illustration (fig. 1), being of all Fic. 2.—The Mediterrane- Fig. 1.—The fig moth (Hphestia cautella) : a, Moth with an flour moth (£phes- expanded wings; b, denuded wings, showing venation; ce, tia kuehniella) : Larva, larva, full grown, dorsal view; d, two egg masses. a, bD, ¢, dorsal view. (Author’s About 4 times natural size; d, more enlarged. (Original.) illustration.) a similar gray color, but it may be readily known from the former by the strong subdorsal line of the cilia of the hind-wings. The markings of the fore-wings are much more suffused than in the other two species, and the line across the basal third is whitish, more nearly straight, and bordered by a prominent, dark, suffused band. In the others this line is irregularly dentate or zigzag. The color of the fore-wings varies, some individuals being fawn color with scarcely any dark markings, while Ohio and District of Columbia series are considerably darker than either Auehniella or elutella and in some cases are very strongly suffused with reddish scales. The following technical description of the moth is copied from Barrett :*¢ ¢Numerals in superior type refer to corresponding numbers in the bibliographical list, p. 39. DESCRIPTION OF EARLIER STAGES. 11 TECHNICAL DESCRIPTION OF THE SPECIES, Fore-wings narrow, especially at the base, costa less arched than in the preced- ing species [/iculella Barr.]. Costal lappet with a broad tuft of scales. Fore- wings pale fuscous with a yellowish tinge, scales large and coarse, and easily rubbed off. First transverse line at one-third the length of the wing, fuscous, ill-defined, straight, and very slightly oblique. Second line parallel with the hind margin, pale, faintly edged with fuscous, often nearly obsolete. Usual two dots on the disc oblique, fuscous, hardly discernible, cilia yellowish- fuscous. Hind-wings white, with scattered fuscous scales, and a faint brown margin, cilia white. Male with one ochreous tuft at the base. Head, antennz, palpi, thorax and abdomen yellowish fuscous. Antenne simple beyond the thick basal joint. The wing expanse is from 14 to 20 millimeters. DISTRIBUTION. Like other species of the genus, the fig moth is supposedly of Asiatic origin. Judging from its abundance in Turkey in Asia that coun- try would seem to be what Packard terms the insect’s “ metropolis; ” in other words, its original or acquired locality of greatest abun- dance. However that may be, it is now, judging by published and office records, as well distributed as perhaps any of the Phycitide with the exception of the Indian-meal moth (Plodia interpunctella Hiibn.), which is more nearly omnivorous in habit, and, therefore, more nearly universal in occurrence. The known distribution includes Ceylon; Egypt; Smyrna, Turkey in Asia; China; Cochin China; Japan; Siberia; England; south-cen- tral and southern Europe; Venezuela; Guayaquil, Ecuador; Jamaica and Trinidad, British West Indies. In North America it is known in the following localities: Montreal, Canada; Milton, Mass.; New York, N. Y.; Washington, D. C.; Milwaukee, Wis.; Calla, Ohio; Hershey, Pa.; Guthrie, Okla.; Wichita, Kans.; Miami, Fla.; New Orleans, Morse, and Lake Arthur, La.; Galveston, Dallas, Sherman, San Antonio, New Braunfels, Fort Worth, Wichita Falls, Beaumont, Houston, McKinney, and El Campo, Tex. DESCRIPTION OF THE EARLIER STAGES. The egg—The egg is whitish when first laid but turns after a few days to ochreous and, just before hatching, often, in parts, to orange. In form it is oval, sometimes approaching oblong-oval, often with a distinct nipple at one extremity. Its surface is subopaque, strongly rugose; the lengitudinal rug are coarse, short, arranged in rather irregular alternating rows of about 24 and, with the transverse smaller rugee, give a somewhat reticulated appearance. The smaller ruge are fine and cilia-like, radiating from the longitudinal ones. 12 THE FIG MOTH. The egg is subject to considerable variation in form. Measure- ments of five eggs showed the following average: Length, 0.33-0.38mm.; width, 0.22—0.32mm. Two groups of eggs are shown, highly magnified, at fig. 1, d. The newly hatched larva—The larva when first hatched is deli- cate, white in color, sparsely hairy, and is about a millimeter long, being about six times as long as wide when contracted. It is widest at the head, which is light brown. The eyes are small and nearly black. The first thoracic segment is nearly as wide as the head, per- ceptibly darker than the remaining segments, which are clear white and less than four-fifths as wide as the head. The legs are long, par- ticularly the thoracic ones. The full-grown larva.—The full-grown larva or caterpillar is of nearly the same form as that of the Mediterranean flour moth, E’phes- tia huehniella (see fig. 2.), and faintly marked individuals would easily be mistaken for that species. It differs chiefly in its smaller size, being a third smaller than the flour-moth larva, in its darker color, and in its more prominent piliferous dots, which, with the pink or flesh tints which are arranged longitudinally along the dorsum, give it a distinctly striated appearance. DESCRIPTION. The full-grown larva is cylindrical, about six times as long as wide, generally of similar form to H#. kuehniella. Ground color dirty whitish, very pale greenish, or very light buff, with an overlay of rather dull pinkish tints arranged in more or less definite longitudinal rows on the dorsal surface. Surface very finely granulate. Head about half the greatest width of the body, ochraceous or cinnamon rufous in color, darkening toward the mouthparts. Thoracic plate (cervical shield) of similar form to that of kwehniella but faintly tinged with blackish anteriorly and much darker, nearly black posteriorly. Piliferous dots or warts, and particularly the other markings, nearly as in kuwehniella, but all dots of darker color, nearly black, larger, and more conspicuous. Ventro-lateral and ventral rows quite conspicuous, the four pairs of rows presenting, with the banded pink coloring of the dorsal surface, a distinctly striated appearance. Posterior fold of abdominal segments not noticeably smaller than anterior, Length, 9.5-12.5 mm.; width, 6.2 mm. In appearance more robust than H. kuehniella when contracted and when at rest, and more slender when ex- tended. tc 100. 212 | ® Wswdow se. 100 212 | After taking them from the water they were hung in large-meshed bags to dry in the wind and sun. When examined August 25, the eggs in lots 3, 4, 6, 7, and 8 had entirely collapsed, and were par- tially collapsed or at least dented in lots 2 and 5. The eggs in lot 1 were apparently unharmed by the heat, but two days later were discolored perceptibly, and showed no signs of vitality. By Sep- tember 3 larvae were working in almost every lot of figs experimented upon, but these had undoubtedly hatched and entered the figs previous to the boiling, as they were too old to have come from eggs present on the outside of the figs when they were boiled. The conclusion is that boiling the figs in water containing 24 per cent salt for an exposure to exceed 30 seconds and temperature to exceed 80° C. (176° F.) will kill all eggs on the outside of the fig, but will not kill larvee within the fig, even though the temperature is increased 20° C. (36°F): DISCONTINUING THE RETENTION OF FIGS INLAND. Between the fig “ depot” of the interior and the packing “ khan” of Smyrna measures of precaution against worm infestation are unnecessary, as the moths have no access to the figs while they are in the goat’s-hair bags. Promptness in delivery to the packers is the all-important thing to be observed at this period of the fig’s handling. Two weeks’ delay brings most disastrous results. During this time the worms which have hatched from eggs laid on the “serghi” or in the “depots” are doing their worst damage and are growing rapidly to a size that renders their presence in the figs most offensive. Moreover, the physical condition of the fig is in- jured by delay in shipment to Smyrna. 52 REPORT ON THE FIG MOTH IN SMYRNA. After inquiry, the writer is convinced that the railroad is able to transport the fig crop direct to Smyrna as promptly as it comes to the villages from the orchards, and that the packers in Smyrna are quite as able to handle it as fast as it can be turned over to them. From our point of view there is no reason, therefore, why figs should be detained in the interior unventilated in the bags, or in piles in the fig “ depots” exposed to moths, flies, and other sources of con- tamination. A week’s time is more than sufficient for the figs to reach the packer after they have been gathered from the “ serghi.” Observations show that most of the crop is held in the interior some time after harvesting, in many cases more than a month. The object of this is to bring better prices to the growers and the middlemen, at the expense of the packers, and to correspondingly increase the reve- nues to the local Government, regardless of what the consequences may be to the product or to the consumer. The practice of “holding” the figs by the producers and middle- men is of recent origin, and apparently is growing. So long as the responsible parties realize large profits from such a practice, as they undoubtedly do, it is not likely to be discontinued, except by stringent action on the part of those who consume the figs and are forced to pay highly for the injuries done. The packers are in no position to con- trol the supply, and can do nothing better than to take whatever figs they can get from the peasants and their representatives, at such time and price as offers, charging a correspondingly higher price for the packed figs. Americans may expect in the future to pay a higher price for figs inferior to those now imported, unless some decisive «ction is taken to stop this unwarranted retention of the crop inland. ELIMINATION OF LARVZE IN THE “KHANS.” The Smyrna “ khan” is not responsible for the wormy condition of figs. But as the packer is-responsible for the fig reaching the con- sumer, he also must be held accountable for the condition in which it reaches the consumer. If the fig is laden with “ worms,” he must rid it of these before it can be imposed upon the public as a sanitary article of diet. The experiments conducted in the “khans” were undertaken with the hope of discovering # means by which the packers could profitably furnish the American importers with sani- tary figs, free from fig “ worms” or other insect pests. In contemplating a means of eradicating larve from figs in the “Ihans” considerable dependence was placed upon the method used in this country for freeing flour mills of the related Mediterranean flour moth (E'phestia kuehniella) , viz, by hydrocyanic-acid gas fumi- gation. After examining the “khans” several reasons were found why the fumigation method could not be used: (1) Whatever venti- lation openings occur near the roofs in these buildings are not Bul. 104, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XIV. Fic. 1.—A HAND VACUUM MACHINE FOR EXTRACTING AIR FROM JARS OF FIGS, AND ITS OPERATOR. Larvee do not suryive in jars of figs so treated. (Original,) Fic. 2.—OVEN FOR STERILIZING FIGS BY DRY HEAT, WITH LOADING FRAME EXTRACTED; EMPLOYED IN A “KHAN” IN SMYRNA. By subjection to dry heat a very large proportion of lary in the figs is destroyed. (Original.) Bul. 104, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XV. Fia. 1.—STEAM DISINFECTING CLOSET, WITH LOADING FRAME EXTRACTED, WHICH COULD BE EASILY ADAPTED FOR STERILIZATION OF FIGS AND DESTRUCTION OF FIG-MOTH LARVA. (ORIGINAL.) » . ee Fia. 2.—INTERIOR OF STEAM DISINFECTING CLOSET WITH ENDS OPEN AND LOAD- ING FRAME EXTRACTED, SHOWING ARRANGEMENT OF PIPES WITHIN. (ORIGINAL.) ‘ ELIMINATION OF LARV& IN ‘‘ KHANS.’’ 53 furnished with glass and are often so large that it is impossible to make them air-tight; (2) the supply of figs in a “khan” does not remain, but passes through in a very short time, usually a day or two, which would necessitate fumigating several times a week. This would be too expensive a process, as well as impracticable, because it would endanger the occupancy of the building the following day. The proportion of air space in a “khan” to the amount of figs to be treated Would make fumigation totally impracticable (Pls. XII, fig. 2, and XITI, fig. 1), and the packers are emphatically opposed to sub- jecting their wares to the action of such deadly fumes as those of hydrocyanic acid. 66 EXPERIMENTS IN THE “ KHANS.” The simplest possible treatment for the destruction of foreign life in any article of food, viz, subjection to heat, suggests itself as more economical and easier to apply than any other method. Ex- periments were made using three distinct methods of application, i. e., by steam, hot water, and hot air. The results obtained by using any of these do not vary greatly, though the details of the applica- tion, the required temperatures and lengths of exposure, and the drying where water is used, necessarily differ much. Experiments were also made using a vacuum treatment. In conducting experiments for the eradication of fig-moth larvee by various methods the writer was extended many courtesies by packers of figs in Smyrna, some of whom had been using the same methods with practical results for some time, and had apparatus in their establishments for the purpose. In one case an expensive steril- izing outfit was installed for the special purpose of making ex- periments to determine the practicability of subjecting figs to special treatment to kill the “worms.” Among Smyrna fig packers, who seemed particularly interested in this phase of the fig industry and to whom the writer is indebted for material assistance in perform- ing the experiments, may be mentioned Mr, John Manola, Mr. Aram Hamparzum, and the manager of his “ khan,” Mr. Vedova; Messrs. A. Reggio and sons, and Mr. §. A. Stassinopulo. DESTRUCTION OF LARV4t BY VACUUM TREATMENT. Attempts were made to free the figs of “ worms” by subjection to vacuum, but with little success. An experiment was performed on September 26, in a “ khan” in Smyrna, to determine whether vacuum treatment could be successfully applied to layer figs in boxes to kill the larve present. A number of larve, found crawling up the wall above a pile of refuse figs, was inclosed in a fig jar, and put into a 54 REPORT ON THE FIG MOTH IN SMYRNA. vacuum machine, and the air extracted from the jar. (See Pl. XTV, fig. 1.) A day later the larve were alive and apparently healthy, but were quite inactive. On September 30 they were still alive and healthy, but seemed able to move only the fore part of the body, and that very feebly, spinning silk about them in apparent effort to make cocoons. When examined on October 8 they were in the same positions they had had a week previously; but by this time they showed almost no movement, at least no more than feeble agitation of the head, in evident discomfort. They had shrunken from their former size, and some had spun abundant silk; but none of them retained sufficient energy to spin a cocoon. They looked very sick, but were all living. By October 21 they were still more shrunken, and a few of them quite lifeless, though the majority showed by their color that they were not dead. From the experiment it is plain that larve, though they might survive, would not continue to feed and to do damage if the vacuum were sustained about them. The application of a vacuum treatment to figs in boxes, however, would prove quite useless, since the larve would immediately revive and become active when brought back into the air. To render the larve inactive and thus innocuous, the vacuum must be long sustained, which is possible only by putting all figs in glass jars—a very expensive process. RIDDING FIGS OF LARVZ BY STEAM, Experiments were made, October 6, to determine whether larve may be killed by subjection of infested figs to steam in confinement in a large steam disinfecting closet used in a Smyrna hospital for steril- izing clothing. The closet was tubular in form and horizontal, both ends opening to allow the entrance of one loading cage filled with clothing, while the other was being extracted at the opposite end for reloading. (See Pl. XV, figs. 1,2.) The loading cages ran on rails on frames at each end of the closet, adjustable to similar rails inside. The steam was applied from an adjoining boiler, the pressure being allowed to reach about 10 pounds, at which point the temperature of the steam was 115° C. (240° F.). A number of “natural” (dried) figs that showed traces of the presence of larvee within them was introduced into the centers of two 25-pound jute bags of figs. The first bag was allowed to remain in the steam closet under full pressure of steam for 10 minutes, the second for 30 minutes. When the first bag of figs was examined following the steaming the larve were found dead in all infested figs within 3 inches of the surface of the bag. Of 18 larve taken from figs at or near the center ‘ ELIMINATION OF LARVE IN ‘‘ KHANS.”’ 55 only 3 were dead. Five more, that were stupefied, slowly recovered. In the bag exposed 30 minutes all larvee near the surface were dead. Of 15 larve taken from figs at the center of the bag 13 were dead, or so badly injured that they did not revive, and the other 2 were sickly. The following table gives percentages of larve killed by the steam at center of bag: Temperature. | After scalding. ae Exposure) Number : = Pancant 1 Silicate ieee a Bg killed. °C, | ep, |minutes.| larve. | piving. | Dead. 115 239 10 18 15 3 17 115 239 30 15 2 13 87 When the bags of figs were taken from the steam closet they were badly soaked with water, those portions not dumped remaining wet for hours and the figs remaining very sticky and disagreeable. Samples of figs scalded by steam were sent, about October 20, to Washington. At the time of sending, those scalded for 10 minutes were almost dry, while those scalded for 30 minutes were still damp. Examined by the writer in Washington, two months later, the figs were nicely sugar-coated ; but it was noticed that all broken or injured figs, as well as many that were uninjured, were badly soured. The conclusion is drawn that it is practically impossible to suc- cessfully sterilize figs by steam while in bags. The presence of so many soured figs among those experimented upon seems to make the practical use of steam doubtful, however well this destroys the larve. Artificial drying of the figs following their scalding would probably prevent the souring. Steam has an advantage over hot air in de- stroying larve in that a very short time is required to apply it and to raise the temperature to the degree desired. In addition, steam has more penetrative power than hot air, and hence requires shorter exposure of the figs. SCALDING FIGS IN HOT WATER TO KILL LARVA, The most extensive experiments were made with hot water. One fig-packing establishment in Smyrna has in operation apparatus for the sterilization of figs by boiling water, and good results were ob- tained from experiments made there in killing the larve. (See PI. XVI, figs. 1, 2.) The required exposure is much shorter than for either steam or dry heat, and the subsequent drying easy. By this process a large percentage of the “ worms” in figs can be destroyed without the additional expense in manipulation of much over a shilling (25 cents) per hundredweight, and if done on a large scale 56 REPORT ON THE FIG MOTH IN SMYRNA. the cost can be reduced. This estimate is based upon figures fur- nished by a packer who uses the process. In the first experiment the exposure of the figs in the boiling water was very much undertimed. A number of figs infested with larvee, selected from a pile of refuse and “hordas”@ in a “khan,” was im- mersed in boiling salt water (2.5 per cent solution, containing also some glucose) at 100° C, (212° F.) for short periods at varying tem- peratures, then put into jars and watched to determine what would later breed from them. The following table gives the temperattres and lengths of exposure and the number of larvee that emerged at intervals of a week or more: Temperature, lengths of exposure, and number of larva that emerged from scalded figs at intervals of a weck or more, Number of larvee present. Tempera- | youre.) Number ms ———— |) hericent ture. of figs. Sept. | Sept. | Sept. | Sept. | Oct. | Oct. killed, 15. 20. 26. 30, 8. 28. at 0 Seconds. 100 10 LOT seein | eee | 2 3 4 60 90 10 11 2 3 7 10 11 13 0 80 10 11 1 2 2 7 4 7 0 70 10 Tn Prete are 3 5 6 if 7 0 100 5 9 2 5 12 17 19 19 0 100 1 9 1 | 3 7 8 10 0 Check. | Check. shee Ase 2 3 5 6 9 0 Since the number of larve present in the figs before boiling was plainly variable, the only conclusion reached by this experiment is that an exposure of 10 seconds in water at 100° C, (212° F.), while it may reduce the number of larvee in the figs somewhat, is quite insuflicient to kill all of them, and that exposures for shorter periods rat lower temperatures than that are practically useless. In another experiment figs similarly infested with larvee were im- mersed in water containing 24 pe cent of salt and a small amount of glucose, boiling at 100° C. (212° FB.) for 20, 25, and 380 second periods. But these exposures, likewise, proved insufficient. Those scalded for 20 and 25 seconds, when broken open after the immersion, were found still to contain living larvee. In the figs boiled 80 seconds that were broken open immediately the larvee were apparently all dead. “Wigs which have failed {o mature on the trees, and which pnanntnnily: oontaine no sugar, being dry, hard, and flavorless. Bul. 104, Bureau of Entomology, U, S, Dept, of Agriculture PLATE XVI. FiG. 1.—-COPPER BOILERS AND GALVANIZED STRAINERS USED FOR STERILIZING FIGS IN A SMYRNA “KHAN,” THE PERCENTAGE OF LIVING LARVA IN THE FIGS IS MUCH REDUCED BY SCALDING, (ORIGINAL.,) FIG. 2,—INTERIOR OF OVEN FOR DRYING TRAYS OF FIGS WHICH HAVE BEEN STERILIZED BY BOILING, USED IN A FIG “KHAN” IN SMYRNA. (ORIGINAL ELIMINATION OF LARV# IN ‘‘ KHANS.’’ 57 The following table shows the number of fig-moth larve that later developed from figs boiled in this experiment : Larvee Temper- | Immer- | Number . resent | Per cent ae sion. of figs. Immediate effect. et. 28, | killed. 1910. SG. Seconds. 100 20 18 | Larve living...... 11 39 100 20 US nie ce (oak ae ees: | ag 56 100 25 17 | Mostly living...... 7 59 100 25 bby gl Paes GOs sete es sock 10 41 100 30 14 | Mostly dead....... a5 64 100 30 14° [aie (3 (0 ee ee 10 29 Examination of the figs immediately following the immersion would seem to show that a much larger percentage of the larve is killed by an exposure of 30 seconds in the water than by shorter exposures, though the number of larve breeding from figs scalded for 30 seconds does not lead to the same conclusion. The percentages killed can not be accurate, since in figuring them it is assumed that each fig contained a single larva, when in fact the number of larve in a fig is variable. Plainly an exposure of 30 seconds of infested figs in boiling water is not sufficient to kill all larvee within the figs. Unfortunately, this fact was not established by the emergence of larve from the boiled figs until the season was too far advanced to make further experiments allowing longer exposures in the hot water. If larvee were not killed in figs immersed for 30 seconds in boiling water it was because the heat did not penetrate to the interior of the fig in that length of time, for contact with water at boiling temperature causes immediate death to any larva. To determine how many seconds or minutes are required after immersion for the interior of the fig to rise to the temperature of the water, the bulb of a high-temperature thermometer was inserted to the center of 3 large figs successively, which were immersed in water at 100° C. (212° F.) and the temperatures recorded every half minute. The first fig was immersed in a large sterilizing kettle at a “khan” and the temperatures recorded for only 74 minutes. The others were immersed in a small vessel of boiling water in the laboratory and the temperatures recorded for periods of 16 minutes. 58 REPORT ON THE FIG MOTH IN SMYRNA. The fellowing table gives the rate of rise in temperature of the interior of the three figs and the resultant average rise. The average for periods of over 74 minutes is taken from two figs only: m : ee Average tempera- Temperature readings. I 8 ture. Rate of increase in tem- = Centi- | Fahren- | perature. No.1. | No.2. | No.3. | grade. heit. Pp Minutes. "G. Ge "0% e S VC; (2) 45 204 204 284 BS... QU eer eee 3 50 27 28 35 95 12 1 55 41 394 453 113 18 13 60 53 49 54 129 16 2 65 63 57 612 143 14 2% 70 714 633 684 155 12 3 74 774 69 734 1644 94 3k 78 824 74 78% 1722 83 4 813 864 774 82 1794 63 44 844 894 814 85 185 54 5 86 92 833 874 1883 32 54 87 94 864 8&9 192 24 6 88 96 883 90% 195 2 63 89 974 904 92 1973 13 7 90 98} 912 934 200 14 7% 91 994 932 944 202 1 Can pag Sanaa 100 942 974 740 Peal Ee Rees et al (eatectecr 1004 953 98 2084 14 CST Eas ees ae ae 101 964 982 2093 14 Cy Gaeecseoe 1012 973 993 211 14 LOM tet sciseeee 1013 984 100 212 1 (GY nl Se Gee ee 1024 99 1003 213 1 1b | eee ees 1023 993 100% 2132 3g Is Set eee see 102 100 1014 2144 Z NO? || 28 Sees 102 1003 1018 215 z 1D 2 S| esas pec 103 1003 1014 2154 4 134 aE ess eee 103% 1014 1024 216 3 VOR Gl eesclec ects 1034 1015 1023 2163 x Ayal MR Es Ss 1034 101 1022 2163 4 iE al Baer e one 1032 1024 102 217 4 US ede cere 1033 1024 103 2174 4 GS ae | ee eS ae 1033 1022 103% 2174 1 I) GNSS ee cease 1033 102% 1034 2173 i a At immersion. Since the rise of temperature was variable in the three figs, to reach more nearly the exact rate of rise an average was taken of recorded temperatures from all. Thus, for the interior temperature to reach 90° C. required in the first fig 7 minutes, in the second 5 minutes, and in the third 64 minutes. For the interior of the average fig to reach 90°, therefore, would require about 6 minutes. That 100° C. is necessary to cause immediate death to larve does not mean that figs must be boiled 10 minutes to kill the larve in them. Larve will as surely succumb to a temperature of 90° C., if sustained for a longer period, as to 100° C. in a short period. The accumulative heat at lower temperatures of the fig up to the point where the “ required ” temperature is reached has a decided devitaliz- ing effect upon the larva. In boiling figs, larve will perish some time before an interior temperature of 100° in the figs is reached. Therefore it must be learned by further experiment what tempera- tures below 100° C., sustained for what lengths of time, will prove ‘ ELIMINATION OF LARV IN ‘‘ KHANS.’’ 59 fatal to larvee before it can be stated exactly how lon boiled to kill the larve inside of them. Many packers complain that figs which have been boiled in hot water sour in a few weeks. If this be true, it is because the figs are g figs must be boiled too long, i. e., longer than is necessary to kill the insects. Figs scalded by the writer in early September had up to December 20 shown no indication of souring. The experiments that were made to determine the exact effect upon figs of boiling them to kill insect larvee were performed in one of the larger “ khans” in Smyrna. Two 5-pound boxes of layer figs, one of “4-crown” and one of “7-crown,” and another box of ‘“ Locoum ” figs were boiled and packed in the presence of the writer. Three identical boxes of figs that were not boiled were also packed the same day for use in “checking” the experiment, and all were shipped to Washington, D. C., for later observation and comparison. The figs were scalded in a 2.5 per cent salt solution at a temperature of exactly 100° C. (212° F.) (taken by a high-temperature thermometer) for 10 seconds, then drained and put into a screen-bottomed drying tray and immediately carried into the packing room. When first taken from the hot water they had apparently absorbed a small amount, making the skin semitranslucent. Packing began exactly 5 minutes after the scalding. By this time all excess moisture on the outside had evap- orated except that held in the cracks and folds of the skin. 'Ten min- utes later the remaining moisture had also evaporated. At this stage the figs differed from those not scalded in that the skin was quite translucent, as though retaining a small amount of moisture, and in being rather less sticky and far softer and more flexible, and easier to pack into layers. When the boxes of scalded figs were opened up the following January and February in Washington they were in prime condi- tion and noticeably free from attack of larve. The only objections to them were their stickiness and a very slight flavor of acidity noticeable in some figs. In spite of these objections they were cleaner and much preferable to the figs not boiled. Some packers contend that boiled figs are darker in color and, therefore, less desirable; but so long as the figs are not injured in quality by the boiling, it is reasonable to believe that their freedom from “ worms ” will more than compensate the loss in eolor. Almost all packers boil the figs intended for their own consumption, but strangely can not afford to boil those intended for sale, or find reasons not to do so. APPARATUS FOR STERILIZING WITH HOT AIR, Dry heat has proved to have advantages over the hot-water method. The time wasted in the subsequent drying of the figs is eliminated, 60 REPORT ON THE FIG MOTH IN SMYRNA. and there is less tendency for the fruit to acidify, as occasionally occurs when it has been boiled. The color, too, is if anything less affected by dry heat; though this is difficult to determine positively, as experiments were made with a different lot of figs from those boiled, and under different conditions. The disadvantage of the dry-heat process as compared with hot water is the much greater exposure required, since time is an important item in the figuring. Tt is also more difficult to maintain a uniform temperature. Another respect in which the dry process is inferior is that it does not remove filth and destroy microbes on the outside of the fig, as does boiling. At a large khan in Smyrna has been installed an oven, heated by gas, for experimental work in the destruction of fig-moth larve in figs. The dimensions of the oven are 2 by 2 meters by 3 meters long. Both ends open out, and are furnished with double doors that swing vertically. Passing through the oven is a track of two rails 14 meters apart, on which run two iron loading frames on wheels. The capacity of each frame is about 4 to 54 tons, depending on whether the figs are loaded in sacks or in the woven baskets piled one above the other. The object of having two frames is that one may be reloaded while the other is within the closed oven and the figs are being sterilized. The oven is made of sheet iron 4 mm. thick. The doors are covered outside with sheet asbestos, with an air-space 1} inches in depth be- tween it and the sheet iron. The sides and top are covered with white planking three-fourths of an inch thick set out from the sheet iron, with intervening air spaces of depths of 6} and 43 inches respec- tively at sides and top. The object of the air spaces is to prevent burning of the wood and radiation and loss of heat. Paper put into these air spaces, with asbestos next the iron, would still further con- serve the heat. The oven is heated by gas, which is furnished by a large series of burners on a sliding frame that passes under the oven. Two thermometers are inserted in one of the doors, by which the interior heat may be determined and regulated. The entire cost of the oven was about £400, and the cost of the gas is about £3 for each 10 hours of use. Considerable loss of heat accompanies each opening of the doors and insertion or extraction of the loaded frames. To ascertain the extent of this loss and the relative length of time required for the heat to again rise to a point sufficient to kill larvae, a loaded frame was inserted in the oven and a tabulated record made of the temperatures, taken at intervals of every quarter or half minute during its exposure of 10 minutes and an additional period after its extraction. The following figures give the temperatures of the interior of the oven before and during the introduction of the figs, and the Doors opened. . Figs introduced Doors closed. . Figs in oven. . ELIMINATION OF LARVZ IN time required for the temperature to rise moved : ID ORAL ce | Ne he ae oe eerie Figs removed Doors closed . Oyen empty - é Time. ‘ KHANS.’’ Temperature. Gs SHOE 132 270 120 248 110 230 100 212 97 207 95 203 944 202 95 203 96 205 98 208 100 212 102 215 103 217 104 219 105 221 106 2224 106% 224 1074 2254 108} 227 109 2284 109% 2292 1104 231 1114 2324 112 2333 94 201 92 1974 92 1973 94 201 97 2064 100 212 104 219 108 226 1113 232 1173 243 1214 251 125 257 128 262 1304 266 132 2694 133% 2723 135 275 136 277 137 279 138 2804 1383 282 1394 283 140 284 1404 2844 1404 285 1403 . 2854 61 after the figs are re- Rise (+) or drop (—) each half minute. NNNWRWONR Ee Ree eRe ee eee RR RP RH OP Go) Co top to to bop +4+++4++++4+4+4+444 mR Re btw ROI OO BR The results of the experiment are more variable than constant. The temperature dropped 40° F. during the first opening of the doors, and 28° more after the doors were closed, due no doubt to the heat required to bring the frame and figs up to the temperature of the oven. During the second opening of the oven the temperature dropped 36°, and rose immediately, as no more figs were introduced, hence no heat absorbed, after the doors were closed. From the mini- mum heat, 202° F., to the maximum heat, 233.5° F., the temperature of the loaded oven rose 31.5° in 8 minutes. empty oven rose 85.5° in the same length of time, or from 197.5° to 283° F. The temperature of the 62 REPORT ON THE FIG MOTH IN SMYRNA. The following table gives some idea of the comparative time re- quired for the temperature to rise in the loaded and empty ovens: | penine: Minimum | Maximum ppt Total rise | Average inet age haar pas tempera- | tempera- | ore en do in 10 rise per. |." egal | elosod: ture. ture. minutes, | Minutes. minute. Ercaceeioe adedoss ses... iOS Gre =e pe c esa 112" ee fe: ote =e | 2R Oe apres + Creede 2° Cc. ['230" ee 02S Nene 23384 Re S| QUO ° Wess 34° cen ye Pesca mp ty sero 2eek 92°C nae PEE Cha ne 1408° C ee CREA ERECTOR Bee aee fee OG: 1973° F 1973° F 2854° F 2604° oe S7g0 cal Ge Nees 88,° F. To establish definite laws for the working of the oven upon this experiment would be dangerous. If the rise in temperature of the loaded oven were uniformly 4° F. per minute after the minimum had been reached, the conclusion would be that in order to maintain the temperature of the oven it must be allowed to rise 68° between re- loadings, which is the amount of heat lost during and following the reloading. If the total rise in temperature of the loaded oven is only 3.5° in the first 10 minutes, then the figs must remain in the oven at least 16 minutes longer in order for the oven to regain, at a rate of 4° per minute, the other 64.5° of the 68° lost. This would require a total exposure of the figs of 26 minutes. But as the rise in tempera- ture of the loaded oven would without doubt accelerate after the minimum heat hatl been well passed, the real required exposure of the figs would be between 20 and 25 minutes. If the figs were ex- posed longer than this, with the gas burning at the rate employed in the experiments, the heat of the oven would increase or accelerate with each load of figs until a certain constant of equilibrium was reached. This constant could, however, be regulated by limiting the flow of gas and thus cutting down the source of the heat. SUCCESS OF HOT-AIR TREATMENT IN KILLING LARVA. A number of experiments was made to determine the temperature and length of exposure necessary to destroy larve by dry heat in an oven. The first of these was performed on September 21 in Smyrna, using the oven described above. A number of figs showing the presence of larvae was chosen from a pile of refuse in a “ khan” and subjected to dry heat for varying lengths of time at different tem- peratures. PRACTICABILITY OF STERILIZING ALL FIGS. 63 The following table gives the lengths of exposure, the tempera- tures, and the number of larve that issued from the figs after treatment: . Temperature. pilin hal es Average | Length | Number |———-————| Per cent temper- | of eXpo- | “oF figs, killed, Maxi- | Mini- | 4 verage mabe i uaak? Oct. 16. | Oct. 28 mum. mum. |~ : ae aa S4 oi 7G. bax Gs OR Minutes. 132 92 112 233 20 13 0 0 100 121 93 107 224 15 8 0 0 100 112 94 103 | 217 10 8 0 1 87 94 2 88 190 5 10 8 14 0 It is plain that any exposure to exceed 224° F., for 15 minutes, will destroy the life of practically all larvee present in the figs. This exposure, however, apparently has no injurious effect upon the fruit. A quantity of figs sterilized in the same oven by the management of the “khan” in which it is located was shipped to one of their New York representatives for examination and report. These figs were exposed for 15 minutes at an average temperature of about 212° F. Six boxes of them were forwarded to the Lederle labora- tories, whose report on their condition, dated November 1, 1910, is summed up in the following table:¢ Percentage Treatment. eter Ene pee General condition of the figs. of larvee. Unsterilized... =... 22:-- Layer. .... 100 12 LEMMZEG so dececsecemcle donseees 100 None. | Less fermentation in top layers. More fer- mentation in bottom layers. Wirsterized so oecc == oe) =< Go. F458 84 6 | Contain living molds. WHENNIZCE pet ecs ses coal Core 89 None. | Clean and moist; no molds. Slightly greater fermentation. Unsterilized=.-3-<=5.~: Macaroni. . 85 79 BLCELIZEC ere loci e = |e dos recs 68 56 | Slightly greater fermentation. In the layer figs sterilization by hot air destroyed all larvee in the two boxes examined. In case of the “macaroni” figs the same treatment reduced the number of larve present over 25 per cent without perceptible injury to the figs. These results argue very strongly for the use of dry heat, in preference perhaps even to steam or hot water, in ridding dried figs of the objectionable larve. PRACTICABILITY OF STERILIZING ALL FIGS IN SMYRNA. Some packers hold that in sterilizing figs the dead bodies of larvee remain to decay inside the fruit, whereas if not killed the larvee 2 These figures were given by kind permission of a dealer of figs in New York City. 64 REPORT ON THE FIG MOTH IN SMYRNA. escape from the boxes during transit to America, leaving behind only their borings and excrement. This objection is not a reasonable one: First, because in fact a very small percentage of larvee escapes in transit, the majority remaining within the boxes and crawling over and littering many more figs than are required for their sustenance; secondly, the body of the dead larva either dries or becomes perfectly preserved by the sirup of the fig and indistinguishable from it, leaving no outward trace to indicate its presence in the fig. The larve are not injurious when eaten with the figs, the objection to them being the unsightly condition their work gives to the fruit. If figs are delivered to the packers promptly from the interior, i. e., within a week after being gathered, the majority of larve will be too small to be objectionable or even distinguishable at the time the figs are sterilized. As attested by a number of the large fig packers in Smyrna, the installation of machinery adequate to sterilize the entire output of packed figs from a “khan” is quite possible. Packers are, more- over, willing to proceed immediately toward that end if sterilization of figs (or whatever term we choose to use for the process of killing the “ worms”) is insisted upon and imposed with equal rigidness upon all. So long, however, as some packers can find means of evading the trouble and expense of sterilizing, and are thus enabled to undersell those packers who are put to extra expense in improving their product, and are at the same time assured of being able to sell their figs—or are perhaps even given a preference by some American importers because of the lower price they quote—it is not likely that much advance will be made in the way of sterilization. These things alone keep many packers from investing on a large scale in improvements that would greatly benefit the trade. In order to progress they must have the protection of this Government. Without such action as can be taken against the fig moth in the “khan,” the insect will only with the greatest difficulty be eradi- cated or even greatly reduced in number in figs coming to this coun- try. There are several species of parasitic enemies of the fig moth present in Asia Minor, and often as high as 40 to 50 per cent of the larvee are destroyed by them; but, as in all similar cases of insect parasitism, the eradication of the host is accomplished after the worst of the damage has been done. The larvee, until they are full grown and about to leave the figs to pupate, do not succumb to the attack of parasites. The combined activities of all the parasites prove to be of little service in relieving the “ wormy” condition of figs, so we must depend exclusively upon artificial means. SUMMARY OF PREVENTIVE MEASURES. 65 SUMMARY OF PREVENTIVE MEASURES. In summing up the measures which will prove most instrumental in the eradication of the fig moth, we find that they fall into two classes—those of prevention and those of destruction. In the first class there are four very important measures to be observed: (1) The rapid disposal or destruction of the June crop of figs; (2) the covering of the figs at night while on the “serghi”; (3) the screen- ing of the fig “ depots” in the interior; (4) the prompt delivery of the figs to the “ khans” after they are gathered. These are all ex- tremely difficult to enforce, especially in a country like Turkey, where superstition is the ruling law of the lower classes. Without special legislation on the part of the Turkish Government we can scarcely hope for any decided change, for some time to come, in the customs that now prevail. The last of these four measures of prevention— the prompt delivery of the figs to the packers—should be insisted upon in so far as possible. Since dependence must be placed upon destroying the larve in the figs, it is highly desirable that the larve be no older and larger than necessary when killed, if it is intended to save the appearance of the fruit. Of the three methods mentioned for destroying the fig-moth larvee in the “khans”—by steam, hot water, or dry heat—it remains for the packers to demonstrate by actual experience which is the more practical. Experimentation has shown that each method has its ad- vantages, and each is capable of eradicating the larve under proper conditions. It would be well to determine the temperature and length of exposure necessary to kill the “worms,” and leave to the option of the packer what method he may prefer. It must be em- phatically understood that prompt and decisive action is necessary on the part of one or both of the Governments interested if any decided improvement is to be expected in the present methods of manipulation and packing of figs, of a character that will insure their freedom from larvee. O 6794°—Bull. 104—1i a) 2 SS eee siti {$5 phat sit fiG ud? icra Be pe Paton: of! of elder ese Lard sie “pet aie Bebe ei} 2c] boddser Wine fede eee ant er d ye ap ea real of ntticsitea ts Menges oe aaae Same aruisrsccies ails on amenel BEN oi Kad OT 7 ~~ * a F Fo 7 a es , ad, Teer ih i S « = 7 - a r . 7 7 — cid = - ro 20 hod ie oe tr A Raat Jenstrogene: S967 7: ; a * utit AG atbdve eee : i oe reo ti : “Sige aa “oil dt aie Bis ik lL (SSco ies Si: it Shite ns OME eee) tye [ Ee eee Wht. Ee % ah a SY : Teme g: sates a eS at) Yi 22 Soe Bate Tn aan br eee Brit + Oty Ge" Gigs. GI eit Sine ¥ — TOLD eed 347, OREM MVTH “PiiE seer eu kon Hslaty ve A et eee eRe . Siti nt: tail ide joa ily aE Sein saab ne: Ui et thtuig. 2) 4b Age Gaim ones “ti 2 Saliok ied Tithe oe madd Bt int f ‘ : ioe? Sie Xa: hey mvss! dion-diPaee ‘Shai “ot hoi inoue sane Ot Sol pier Tete Ey a ohne foul desig cacial > Ls oy ri 4 bs a ts i a ©) at} MHiy Sides aes Gf ysl ea «pit Seed ge ubsiy ii Sia ee ot ome on vertnr ti. rtalet ‘ ag ail’ bide ae dil vd easruat Oy cae ee Oot Oy he Jepvilinetg: Ladd i eg pgun a6. bole ohit aitelacirde 596 ate: iF GEES "to Bhoilionr — avi, BAF ‘sit bitrate 3 Sy ed, ae Age ns: adh orizii lity juts sa saieh (hi ean naa j * ~ | 7 r on a | 4 oe Y U.-S. DEPARTMENT. OF AGRICULTURE, BUREAU OF ENTOMOLOGY—-BULLETIN No. 105. L. O. HOWARD, Entomologist and Chief of Bureau. , THE ROCKY MOUNTAIN SPOTTED FEVER TICK. WITH SPECIAL REFERENCE TO THE PROBLEM ~ OF ITS CONTROL IN THE BITTER ROOT VALLEY IN MONTANA. BY W. D. HUNTER, In Charge of Southern Field Crop Insect Investigations, AND F, G. BISHOPP, Entomological Assistant. [In Cooperation with the Biological Survey and the Montana Agricultural College. ] Issuep Novemper 17, 1911. —_ LL a = agithsonian ingzis = Nifptz he4+07b4 WASHINGTON: GOVERNMENT PRINTING OFFICE. 1911. U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN No. 105. L. O. HOWARD, Entomologist and Chief of Bureau. THE ROCKY MOUNTAIN SPOTTED FEVER TICK. WITH SPECIAL REFERENCE TO THE PROBLEM OF ITS CONTROL IN THE BITTER ROOT VALLEY IN MONTANA. BY W. D. HUNTER, In Charge of Southern Field Crop Insect Investigations, AND F. CG. BISHOPP, Entomological Assistant. [In Cooperation with the Biological Survey and the Montana Agricultural College. ] IssurpD Novemeer 17, 1911. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1911. BUREAU OF ENTOMOLOGY. L. O. Howarp, Hntomologist and Chief of Bureau. C. L. MAriatt, Entomologist and Acting Chief in Absence of Chief. R. 8. Ciirron, Hxecutive Assistant. W. EF. Tastret, Chief Clerk. IF. H. CHITTENDEN, in charge of truck crop and stored product insect investigations. A. D. HOPKINS, in charge of forest insect investigations. W. D. Hunter, in charge of southern field crop insect investigations. F. M. WEBSTER, in charge of cereal and forage insect investigations. A, L. QUAINTANCE, in charge of deciduous fruit insect investigations. KE. F. PHInuips, in charge of bee culture. D. M. Rocers, in charge of preventing spread of moths, field work. Rouua P. Currin, in charge of editorial work. MABEL COoLcorD, in charge of library. SOUTHERN FreLD Crop INSECT INVESTIGATIONS. W. D. HUNTER, in charge. F. C. BisHopr, H. P. Woop, W. V. Kine, G. N. Wotcott, engaged in tick investi- gations. W. D. Prerce, J. D. MITCHELL, HE. S. Tucker, T. E. Hottoway, G. D. SmitH, E. A. McGreeor, Harry PINKus, W. A. THOMAS, THOMAS LUCAS, engaged in cotton-boll weevil investigations. A. C. Morgan, G. A. RUNNER, S. E. Crump, engaged in tobacco insect investi- gations. T. C. Barper, C. E. Hoop, engaged in sugar cane and rice insect investigations. R. A. Cootey, D. L. VAN DINE, WILMON NEWELL, A. F, Conrapi, C, C. KRUMBHAAR, collaborators. - 2 LETTER OF TRANSMITTAL. Unitep States DepArTMENT OF AGRICULTURE, Bureau or Entromo.ocy, Washington, D. C., July 20, 1911. Sir: I have the honor to transmit herewith a manuscript entitled “The Rocky Mountain Spotted Fever Tick, with Special Reference to the Problem of its Control in the Bitter Root Valley in Montana,” prepared by Messrs. W. D. Hunter and F. C. Bishopp, of this bureau. The work of this bureau on the spotted-fever-tick problem began in 1909. It has been conducted in cooperation with the Biological Survey of this department and the Montana Agricultural Experiment Station. The investigation of the life history and habits of the tick which transmits spotted fever has revealed certain feasible and eco- nomical methods of control. These methods render it possible to reduce the numbers of the ticks to such an extent that the cases of spotted fever in the Bitter Root Valley will be very few in number, if, indeed, the disease is not eliminated altogether. The plans for this work are outlined in this manuscript. It is recommended that the accompanying manuscript be published as Bulletin No. 105 of this bureau. Respectfully, L. O. Howarp, Chief of Bureau. Hon. James Wirson, Secretary of Agriculture. ai Mw J an zi . i sa = ‘ 4 eh oe | — i Wy ‘ vgn v3 iy nat o> i's - toe *y/ See z ia IEVrreey Lesrrett. ou baie Padus sezad 2 r Were. - : oF Smecoee ‘ i rE CONTENTS: SpmM MEIN ee eee Me nh 66a. < sne oss ose eae ce oe sate tededeseeesomemEne Miereupon wie this bulletins based-it.sece.-. h....-. 222242 scee Secon Possibility of increase of area of spotted fever. .........-...----------------- Importance of the control of the spotted-fever tick ...............--..-------- Summary of facts bearing on importance of tick control.........-...-.------- PaswibuiMonyoL the spotted lever TGK 6.2% 22.4 22> sete e's ao Bota eg aba de ~ oe Peetote POveRuIne aDUMOANGO 47.0 6b seks. ice hearse = asl anatase ear Summary of life history of the spotted-fever tick. ....-........--..---------- Pn eee aria ale Shake esta 8 ae tee ro ae As td ARs eRe on 2S UD TESSEATE CTC) Renee Tain OAS SE RUE 0 cnet Om JaNt Si gegen pe PA 5 eee ee 2 CTE SM ee Re eae ie ee ee ee ee ee ae Sosngisn bie Ory amd bites aco thi 48s). Seth ac mews daa de slehcne - cane (ihe hosamialsset the spotted fever, tick > 1.01454. «oh 4 oF also 5 meee = = = eae Other species of ticks found in regions where Rocky Mountain spotted fever emer an Satire eet Sola 2S Kh 2 nn TM aps agiearyaet a said + Aes dacs - 442 Species of ticks which may play an important part in the dissemination of the disease should it be introduced into new regions............--.-------------- Practical control or eradication of the spotted-fever tick ......-.......-..--- Conditions favoring control. .... Bo eeiry ain ake Sespheaaal~ Sonia = = == Importance of control throughout the Bitter Root Valley............-.--- Remap NCI Ot Ua. comes fe Ose ee ea I cr ur edt SN eae etee sos Handwork in the destruction of the spotted-fever tick .........-.....--- Definite recommendations for control or eradication of the spotted-fever tiem Mneyruer WOOG Valley sss ncvsl sk eo. ook noel eee ee fae Batematedneqst Giworket- fe. eee. 29 4s. Wee Po Eide ee Me Supplementary messi: Comtrol: . | fea Sa fad ec Sit Sec he acek 3 ecesnty for expert: quper vision. 2.0088. 2 So 584. . Seb io ba ee sb ae eeie cose Bibliography of the more important writings on the spotted-fever tick......... LELUST RA RVON'S, PLATES, PuaTE I. Ticksand spotted fever in the Bitter Root Valley, Montana. Fig. 1.— View in Lo Lo Canyon, which leads into the Bitter Root Valley, showing conditions under which ticks thrive. Fig. 2.—Camp laboratory near Florence, Mont., in one of the most heavily in- fested ‘localities ‘known: 2 fi: i2h25 $32 2¢ 5522252305 eee eee II. The Rocky Mountain spotted-fever tick (Dermacentor venustus). Fig. 1.—Adult female unengorged, dorsal view. Fig. 2.—Adult male, dorsal view. Fig. 3.—Adult female unengorged, ventral _view. Fig. 4.—Adult male, ventral view. Fig. 5.—Adult female mr aC OF Gepoartneened. -- or 2. s fe ares Ie ester een cle eee III. Spotted-fever tick (Dermacentor venustus) and Dermacentor albipictus. Fig. 1.—Adult spotted-fever tick which has deposited eggs. Fig. 2.—Larva of spotted-fever tick. Fig. 3—Engorged nymph of spotted-fever tick. Fig. 4—Same, ventral view. Fig. 5.—Adult male of Dermacentor albipictus. Fig. 6.—Adult female of Derma- centor albipithts, witerigerged: . 2. 22a vee fe Sie PIS TEXT FIGURES. Fic. 1. Map showing area in which the spotted-fever tick occurs....-...------- 2. Diagram showing possible seasonal history of spotted-fever tick. - ..-.- 3: Dippime “vate... 55. sol esag- seas ste n eae ae ce oi ee 6 Page. 20 16 27 38 THE ROCKY MOUNTAIN SPOTTED-FEVER TICK, WITH SPECIAL REFERENCE TO THE PROBLEM OF ITS CONTROL IN THE BITTER ROOT VALLEY IN MONTANA. INTRODUCTION. For many years a disease of human beings, known as spotted fever, has been known to occur in certain localities in the Rocky Mountain region of the United States. In fact the evidence is rather conclu- sive that the disease existed before the settlement of the country by white men. At any rate old residents of the Bitter Root Valley in Montana have informed us that the first white settlers were warned by the Indians of the danger of contracting a very serious disease if they visited certain localities. From what has been learned in recent years it is evident that these dangerous localities are the very ones in which spotted fever is now most prevalent. The States in which the disease occurs most frequently are Mon- tana and Idaho. There is no doubt, however, that it occurs in at least portions of other States, such as Oregon, Washington, Nevada, Utah, Wyoming, and Colorado. Definite work on the nature and method of transmission of spotted fever was not begun until 1902. In that year Drs. Wilson and Chowning announced the theory that the “wood tick” is the natural agency through which the malady is transmitted from one human being to another. This hypothesis was based upon three observa- tions: First, that the majority of cases of spotted fever showed histories of tick bites; second, that the localities in which the disease was most frequently contracted were those where ticks were most abundant; and, third, that the season of spotted fever coincided with the period when the ticks were most frequently observed. Drs. Wilson and Chowning had no facilities for proving their hypothesis in a scientific manner, but such proof was soon obtained. Accord- -ing to the late Dr. H. T. Ricketts* the first experiments which re- sulted in proof of the transmission of spotted fever by the tick were conducted by Drs. McCalla and Brereton, of Boise, Idaho, in 1905. In these experiments a tick which was found attached to a spotted- fever patient was removed and allowed to bite a healthy person. In 1Fourth Biennial Report, Montana State Board of Health, p. 106. 8 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. eight days this person developed a typical case of spotted fever. The experiment was continued by allowing the same tick to bite a second person. In this case again a typical case of spotted fever resulted. The results of the important experiments of Drs. McCalla and Brereton were not published by them. In 1906 Dr. H. T. Ricketts, then connected with the University of Chicago, began a series of investigations which must always be considered classic. Not being aware of the experiments of Drs. McCalla and Brereton, Dr. Ricketts started with the hypothesis of Drs. Wilson and Chowning. His first work was devoted to determin- ing whether guinea pigs and rabbits are susceptible to the disease and consequently suitable for inoculation experiments. The original experiments with rabbits were somewhat inconclusive, but it was found that the injection of blood from a human being suffering with spotted fever invariably brought about the disease in guinea pigs. In fact in these animals the disease was found to run a course very similar to that in human beings. It was thus determined that guinea pigs were suitable subjects for experiments to determine whether ticks could transmit the disease. On August 4, 1906, Dr. Ricketts announced the results of the first experiment in the tick transmission of the disease. A small female tick was placed on a guinea pig which had been inoculated with the blood of a patient who died of spotted fever. The tick was allowed to feed on this inoculated guinea pig for two days. It was then removed and placed in a pill box for two days. At the end of that time it was allowed to attach to the base of the ear of another guinea pig which had not been inoculated with spotted fever. After threeand one-half days the temperature of this guinea pig rose and remained above normal for more than seven days. The pig also showed practically all of the other symptoms of spotted fever. In fact, there was no doubt whatever that the guinea pig contracted spotted fever from the bite of the single tick. Asa control on the experiment Dr. Ricketts placed two other guinea pigs in the cage occupied by the animal upon which the tick had been placed. They remained there for two weeks. These two pigs showed no indications whatever of fever. Thus the possibility of infection by contact or by feces was eliminated. The only difference between the conditions surrounding the pig which contracted fever and those surrounding the others was that the former was bitten bya fever tick. During the following year (1907) Dr. Ricketts succeeded in trans- mitting the disease by ticks in a number of additional cases. In one experiment he found that the male tick as well as the female is capable of transmitting the disease. In other experiments it was determined that the larval or nymphal tick may acquire the disease and retain it through the molting period, and transmit the infection in the following stage to another host. The most interesting experi- Bul. 105, Bureau of Entomology, U. S. Dept. of Agriculture PLATE I. Fic. 1.—ViEW IN Lo Lo CANYON, WHICH LEADS INTO THE BITTER ROOT VALLEY, SHOWING CONDITIONS UNDER WHICH TICKS THRIVE. Fic. 2.—CAmP LABORATORY NEAR FLORENCE, MONT., IN ONE OF THE MOST HEAVILY TICK-INFESTED REGIONS KNOWN. TICKS AND SPOTTED FEVER IN THE BITTER ROOT VALLEY, MONT.. lt WORK UPON WHICH BULLETIN IS BASED. 9 ments, however, were with adult ticks. It was found that when an adult becomes infected with the disease, the infection passes through the eggs developed in the tick, so that the young of the next genera- tion may transmit the disease." The main points determined by Dr. Ricketts are as follows: (1) Guinea pigs and certain other animals, as monkeys, are sus- ceptible to.spotted fever. (2) Larval ticks applied to an infected animal contract the infec- tion and are able to transmit it to the following or nymphal stage. (3) Nymphal ticks feeding upon infected animals acquire the power of transmitting the disease as adults. (4) Adult ticks are able to acquire the disease by feeding upon an infected animal and to transmit it through the egg stage to the suc- ceeding generation. (5) Infective ticks are to be found in nature. The transmission of disease organisms through the egg stage of ticks is known in a number of other instances. It is the case with the tick Margaropus annulatus Say, which transmits splenetic fever of cattle in the scuthern portion of the United States. The causative organism of splenetic fever has actually been found in the eggs of this tick. Dr. Ricketts recently made a tentative announcement of the finding of the spotted-fever organism in the eggs of Dermacentor venustus Banks. Future investigation will undoubtedly result in certainty regarding this point. Some of the main points determined by Dr. Ricketts were corrobo- rated about the same time by Dr. W. W. King, of the Public Health and Marine-Hospital Service, whose results were published in the Public Health Reports of July 27, 1906. WORK UPON WHICH THIS BULLETIN IS BASED. The work of the Bureau of Entomology on the spotted-fever tick began in 1908, when the investigation of the life history and habits of the species was undertaken. Plans were made for deter- mining the distribution of the tick and for the exhaustive life-his- tory investigations necessary in the formulation of plans of con- trol. Following the plan for determining the distribution of the tick, two men were selected, one to travel through the southern Rocky Mountain region and the other through the northern. The late Mr. F. C. Pratt made investigations in New Mexico, Arizona, southern California, and Colorado. Mr. W. V. King, whose work as an agent of the bureau began July 1, 1909, made the investiga- 1The Rocky Mountain spotted-fever tick, like a number of other species, exists in four distinct stages, namely, egg, larva, nymph, and adult. The eggs are invariably deposited on the ground in Jarge masses. The larve which emerge from the eggs are minute six- legged animals. After feeding upon a suitable host, they drop to the ground and molt, becoming nymphs. In this stage they have eight legs. The nymph waits until it can attach to a host, engorges blood, drops, molts its skin, and becomes adult. 8464°—Bull. 105—11——2 10 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. tions in the northern Rocky Mountain region. He explored Wyo- ming, Idaho, portions of Utah, and Oregon and Washington. Prof. R. A. Cooley, of the Montana Agricultural College, consented to co- operate with the bureau by directing the work of Mr. King and by submitting specimens from many localities in Montana. During 1909, Mr. J. D. Mitchell, of the Bureau of Etomology, visited New Mexico, and succeeded in determining the southernmost locality in which the fever tick is at present known to occur. The life-history work upon the tick was conducted at Dallas, Tex., by Messrs. H. P. Wood, G. N. Wolcott, and the junior author. This began early in 1909 and has continued without interruption. In February, 1910, a conference was held in Washington, D. C., with Prof. R. A. Cooley and Dr. C. Hart Merriam, then Chief of the Biological Survey, for the purpose of formulating definite plans for the continuation of the work. It was agreed that the determina- tion of the range of the tick should be continued by correspondence rather than by sending men into the field and that the local aspects of the problem in the Bitter Root Valley should be investigated by placing an agent there. The Bureau of Entomology provided the necessary funds and established a laboratory near Florence, Mont. (See Pl. I, fig. 2.) Prof. Cooley agreed to supervise the work in Montana, and was appointed a collaborator in the bureau on March 1, 1910. At the same time Mr. W. V. King was appointed to work under the direction of Prof. Cooley in the Bitter Root Valley. This plan of cooperation has centinued down to the present time. The results obtained have been due, to a large extent, to the energy and acumen of Prof. Cooley and to the high grade of Mr. King’s work. But a special word must be said about Mr. King. Unde- terred by the possibility of contracting spotted fever, he located on an abandoned farm in the most dangerous locality known. In the immediate vicinity a number of deaths from spotted fever had oc- curred within a short time. He remained there throughout the sea- son of 1910, subject to the risk of contracting the fever on his daily trips into the field or from the ticks used in the experiments at the camp laboratory. His devotion to the investigation outweighed all considerations of personal safety. Great credit must also be given Mr. C. Birdseye and Mr. A. H. Howell, of the Biological Survey, for assuming the risk of residence at the laboratory during a por- tion of the season of 1910. Mr. Birdseye continued the investiga- tion of the mammals of the valley in 1911. In addition to the work in cooperation with the Montana Agri- cultural College, in 1910, the bureau undertook to obtain informa- tion regarding the exact extent of the area in which the spotted- fever tick occurs. By means of a system of circulars and the gen- erous cooperation of many physicians and other persons throughout POSSIBILITY OF INCREASED AREA OF FEVER. iiaf the Rocky Mountain region, a very large amount of information was obtained. In fact the correspondents sent in altogether 1,400 lots of ticks, 850 of which were of the fever species. These repre- sented 225 localities in California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. Very many of the ticks received during the course of this work were in immature stages. Unfortunately our present knowledge of ticks is not sufficient to enable us to determine the species to which immature forms belong. This necessitates very special care in rear- ing to maturity the immature forms received. This work was done at Dallas, Tex., and naturally involved a large amount of skilled attention. The information now in hand regarding the spotted-fever tick was greatly increased through the cooperation of the Biological Survey of this department. In 1910 two agents of this survey, Messrs. A. H. Howell and C. Birdseye, were located at the camp laboratory of the Bureau of Entomology near Florence, Mont. These agents were engaged in the collection of wild mammals upon which one stage or another of the spotted-fever tick occurs. This work resulted in showing the relative importance of the different mammals found in the Bitter Root Valley and adjacent mountains as carriers of the spotted-fever tick. It also revealed many points having a bearing on the original source of the disease in nature and on other impor- tant matters. The Biological Survey has also studied carefully the possibility of the eradication or control of all the wild mammals which carry the fever ticks. In September, 1910, Prof. H. A. Morgan, director of the Tennessee Experiment Station, consented to make a trip to the Bitter Root Valley and to advise the forces cooperating regarding the sufficiency of the data obtained and the feasibility of plans of eradication based thereon. Of course the authors have made full use of the available literature on the investigations that have been conducted by other persons. Most useful have they found the first and second spotted-fever re- ports of Dr. H. T. Ricketts, published in the Fourth Biennial Report of the State Board of Health of Montana. POSSIBILITY OF INCREASE OF AREA OF SPOTTED FEVER. The approximate area in which spotted fever occurs has been indi- cated in a previous paragraph. Since it has been shown, however, that a certain tick (Dermacentor venustus Banks) is the only known agent of transmission of the disease in nature, it follows that the possible area in which spotted fever may occur is at least coin- cident with the range of the tick, exactly as the possible range of yellow fever is as extensive as is the area in which the mosquito 12 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. which transmits it is to be found. Extensive work conducted by the Bureau of Entomology has shown with considerable accuracy the area in which spotted fever may be thus propagated. The map (fig. 1, p. 16) shows the area in which the necessary agent for trans- mission occurs, and consequently the possible geographical distribu- tion of the disease. This map is based upon the examination of 850 lots of spotted-fever ticks received from 230 localities during the seasons of 1909, 1910, and 1911. One of the most remarkable features of spotted fever is the fact that strains of different degrees of virulence exist in different locali- ties. In Idaho the death rate is from 5 to 7 per cent. In the Bitter Root Valley in Montana, however, the death rate is about 70 per cent. One consideration which has caused the Bureau of Entomology to concentrate its efforts in the Bitter Root Valley is the possibility that the virulent form of the disease, now restricted to that valley, may eventually be carried into other regions where the presence of the tick would make transmission possible. There are several ways by which the virulent strain of the disease might be carried out of the Bitter Root Valley. It could be taken either by ticks or in the blood of human beings. Carriage by ticks might occur when these animals are transported on men, horses, or cattle. Moreover, tick eggs or other stages of the tick which have been shown to contain the disease organism might be transported in hay or other commodities. ‘There is also a chance that ticks in various stages might be transported on the hides of domestic or wild animals. As regards carriage of infection in the blood of human beings, our conclusions are largely theoretical. It is not known how long the blood of a person who is attacked with spotted fever remains in- fective. It is probable, however, that it is infective for some days before the height of the fever and for some time thereafter. During the period either preceding or following the climax of the disease a person might leave the Bitter Root Valley. If in another locality he should be bitten by the fever tick and the specimen should escape, the establishment of the virulent form of the disease would be accom- plished. In certain diseases similar to spotted fever, such as splenetic fever of cattle, the organism of the disease remains in the blood for many years without causing an acute or noticeable attack. Nevertheless, all ticks which feed upon these apparently immune animals become infected and can transmit the disease in acute’ form to other animals. Although nothing is known as to the persistency of the organism of spotted fever in the blood of persons who have apparently recovered, there is a possibility that it may remain for some months or even years. In this way there is a probability of POSSIBILITY OF INCREASED AREA OF FEVER. 13 considerable extension of the territory in which the virulent form of the disease occurs, by migration out of the valley. Naturally the chances of spread will increase with the develop- ment of the Bitter Root Valley and the growth of shipments of cattle or movements of people to other regions. These considera- tions are sufficient to justify very energetic means for control where the virulent form of the disease now occurs and where, as will be shown in this bulletin, the practical eradication of the tick, and, consequently, of spotted fever, is entirely feasible. It has been shown by experiments conducted in the Institute of Infectious Diseases in Chicago that several species of ticks other than the form which occurs commonly in the Bitter Root Valley are capable of transmitting spotted fever. A very hopeful feature of the situation, however, is that in the valley there is but one tick species which attacks man. Therefore the other species are of no practical importance as regards spotted fever. Even among the species which feed upon the lower animals there are many thousands of specimens of Dermacentor venustus to every one of all other varieties. Moreover, means of control of this one species, such as wili be described in this bulletin, will serve greatly to lessen the number of the other forms. For these reasons, in formulating plans for practical eradication it is necessary to consider only the one dominant tick in the valley. There is one respect, however, in which the discovery that species other than Dermacentor venustus can transmit the disease may be of importance. The other forms occur over wide areas in the east- ern and southern portions of the United States. It is conceivable that if the disease were once introduced in the blood of a human being or otherwise, the other ticks might propagate it and transmit it in regions far outside of the territory in which the fever is now known to occur. But the danger on this score is not so great as might be thought. In the first place, in no localities in the United States are any species of ticks as numerous as is the fever species in the Bitter Root Valley and elsewhere in the Rocky Mountain region. Consequently, the occurrence of anything like an epidemic of the disease would be impossible. Only occasional or rare cases could be expected. In the second place, it can not be foretold whether spotted fever would find general conditions suitable for propagation in localities outside of the Rocky Mountain region. Nevertheless the degree of danger from this source, while perhaps slight, emphasizes the importance of eradication of the spotted-fever tick in the mountain region and also of the discovery of effective means of control for all species of ticks wherever they occur. 14 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. IMPORTANCE OF THE CONTROL OF THE SPOTTED-FEVER TICK. The most conspicuous loss from spotted fever is in human lives. In the Bitter Root Valley it was estimated in 1904 that 200 cases of the severe type of the disease had occurred up to that year. A con- servative estimate of the mortality there, as has been stated, is 70 per cent. This means a loss of about 140 lives in this small valley. At the present time, with an increase in the population of the valley, it is estimated that about 20 cases of the disease occur annually. This means a loss of about 15 lives each year and this loss is certain to increase as the population of thé valley becomes larger. In Idaho it was estimated in 1908 by Dr. E. E. Maxey that the annual average of cases of spotted fever was 375. Undoubtedly, as Dr. Maxey pointed out, this estimate is very conservative. In all probability 500 would be a small estimate. The comparatively small mortality in Idaho would give a loss of human lives each year of about 35. _ Taking into consideration the whole area over which spotted fever is more or less prevalent, it is conservative to estimate 750 cases each year with probably 75 deaths. A great indirect injury the tick does in the Bitter Root Valley is in preventing the proper development of a region favored by a rich soil and by remarkable climatic advantages. As long as it is known that a dangerous disease exists there and that persons who farm or go into the country are especially subject to it, the valley can not prosper as it should. Relief from the tick would imme- diately result in increased land values and larger immigrations into the valley. In a larger way the possibility of the spread of the virulent form of the disease outside of the valley must be considered. This alone would warrant a much larger expenditure than is actually required for extermination or control in the valley. SUMMARY OF FACTS BEARING ON IMPORTANCE OF TICK CONTROL. Tt has been proved beyond peradventure by the investigations of Dr. Ricketts and others that spotted fever is transmitted in nature only by certain ticks. In the region where the disease now occurs it is transmitted to man by a single species of tick. Therefore the rational method of eradicating the disease is to attack this tick. In this way the proper procedure is exactly analogous to that being fol- lowed in the eradication of splenetie fever of cattle from the United States, by the eradication of the tick which transmits it. In the case of splenetic fever, certain more or less effective means of combating the disease itself have been discovered. These are in the form of a method of preventive inoculation and the administration of certain DISTRIBUTION. 15 drugs. In spite of this it has been found that the only hope for the eradication of the disease, or even for practical control, is in the destruction of the ticks. Inasmuch as no means of preventing or curing spotted fever are known, the importance of attacking the ticks is much greater than in the case of splenetic fever. The situation is also analogous to that brought about by malaria and yellow fever, which, as is well known, are transmitted by certain mosquitoes. The control of these diseases in all parts of the world has practically re- solved itself into a warfare against the mosquitoes. These considerations seem to make it very evident that the logical course to follow in the eradication or control of spotted fever is the elimination of the tick. The problem becomes purely an entomologi- cal one. Under these circumstances, it is most fortunate that certain feasible and economical means of eradication, first outlined in a ‘rather general way by Dr. Ricketts, have been placed upon an exact and certain basis by the recent investigations of the Bureau of Entomology. DISTRIBUTION OF THE SPOTTED-FEVER TICK. As is shown in the accompanying map (fig. 1) the range of the Rocky Mountain spotted-fever tick extends throughout the north- ern part of the Rocky Mountain region across the Great Basin to the eastern edge of the Cascade Range. The southernmost limit of the tick is in the northern edge of New Mexico. Although the dis- tribution of the species in Canada has not been determined, there is little doubt that it extends over the southern half of British Colum- bia and the western portion of Alberta. However, only one accurate record of the occurrence of this species in Canada has been made, namely, by Dr. H. G. Dyar, who captured two female specimens at Kaslo, British Columbia, in 1903. While infestation occurs throughout large portions of Montana, Idaho, Washington, Oregon, Nevada, Utah, Wyoming, and Colorado, comparatively small areas in New Mexico and Califcrnia are infested. The tick probably occurs throughcut the entire Black Hills region in South Dakota and Wyoming, although but one collection has been made in that region. Naturally there is no uniformity in the abundance of the tick throughout the territory in which it occurs. ; Our knowledge of the local occurrence of the tick throughout the Western States is not sufficiently complete to enable us to make definite statements as to areas within the whole infested region in which comparatively few ticks are to be found. We do know, how- ever, that certain sections of the country which are unfavorable for the development of the species are only slightly or not at all infested. 16 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. During the investigation about 850 lots of the fever species have been collected. The following is a list of the counties and the num- Ly ch Perr?) ss LF b aa 2: SUNS Pee CA eae | q a 5 = i 1 1 foes H een CO ae 1 t i 1 TEX. all . ' ‘ ' t { t ' ' Fic. 1—Map showing region in the United States in which the Rocky Mountain spotted- fever tick occurs. The degree of shading indicates the relative abundance of the tick in different sections. (From Bishopp.) ber of lecalities within those counties where the species has been taken by the bureau: NUMBER OF LOCALITIES, BY COUNTIES AND STATES, IN WHICH THE SPOTTED-FEVER TICK IS KNOWN TO OCCUR. California.—Modoe County, 3; Lassen County, 1. Colorado.—Boulder County, 4; Clear Creek County, 1; Eagle County, 1; Garfield County, 1; Gunnison County, 1; Jefferson County, 1; Lorimer County, 5; Mesa County, 2; Pitkin County, 1; Summit County, 1. Idaho.— Bannock County, 7; Bingham County, 2; Blaine County, 3; Boise County, 1; Bonner County, 2; Canyon County, 1; Cassia County, 2; Elmore County, 3; Fremont County, 6; Kootenai County, 2; Lemhi County, 2; Lincoln County, 2; Oneida County, 4; Shoshone County, 1; Washington County, 1; Twin Falls County, 1. DISTRIBUTION. Lz Montana.—Beaver Head County, 3; Broadwater County, 2; Carbon County, 1; Custer County, 1; Flathead County, 4; Gallatin County, 5; Granite County, 5; Lewis and Clark County, 4; Lincoln County, 2; Madison County, 6; Meagher County, 3; Missoula County, 8; Park County, 2; Powell County, 3; Ravalli County, 7; Rosebud County, 4; Sanders County, 5; Silver Bow County, 1; Teton County, 2; Yellowstone County, 1. Nevada.—Hureka County, 1; Humboldt County, 2; Lander County, 2; Lin- coln County, 2; Nye County, 3. New Mexico.—Rio Arriba County, 1; San Miguel County, 1. Oregon.—Baker County, 1; Crook County, 38; Grant County, 1; Harney County, 3; Klamath County, 1; Lake County, 1; Malheur County, 2; Sherman County, 1; Umatilla County, 2; Union County, 1. Utah.—Boxelder County, 2; Cache County, 2; Iron County, 1; Uinta County, 1; Utah County, 8; Wasatch County, 3. Washington.—Asotin County, 2; Chelan County, 2; Douglas County, 1; Grant County, 1; Kittitas County, 1; Spokane County, 3; Stevens County, 14; Yakima County, 3. Wyoming.—Albany County, 3; Bighorn County, 6; Carbon County, 3; Fre mont County, 6; Latrona County, 8; Park County, 2; Uinta County, 2; Weston County, 1. The above is far from being a complete list of those counties in which the spotted-fever tick occurs, yet it gives a definite idea of the territory infested. It should be understood that the number of lo- calities given for a county does not represent the relative abundance of the tick in that county. The table includes only the number of localities from which the tick has actually been received. Greater population or a larger number of collectors in some counties has given more localities than in others, while the actual abundance of the tick may be exactly the reverse. Further investigation through- out the Rocky Mountain region will undoubtedly show the tick to be present in the majority of the counties included in the area shown to be infested in figure 1. Dr. E. E. Maxey? (1908, p. 4) reports that the tick has been found to occur in all of the counties of Idaho with the exception of Latah. As is pointed out in Circular No. 136 of the Bureau of Entomology, the fever tick is known to occur at various elevations from slightly over 500 feet to nearly 9,000 feet above sea level. The species occurs in greatest abundance in the area known as the transition zone. It is also commonly found in the Canadian and Upper Sonoran life zones. FACTORS INFLUENCING ABUNDANCE. The occurrence and abundance of this tick within a given locality are dependent, to a large extent, upon the presence of favorable con- ditions for development. These conditions are, first, the existence of the small mammals which serve as hosts for the immature stages; second, the presence of large mammals upon which the adults may 1See Bibliography, p. 45. 8464°—Bull. 105—11——3 18 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. engorge, and, third, the existence of a certain amount of protection for the development of the stages when not on hosts, As a rule the abundance of ticks is dependent upon the amount of vegetation. Lands upon which some fallen timber and undergrowth occurs are usually found to harbor ticks in abundance, provided the hosts—cer- tain small mammals and domestic animals—are also present. In the Bitter Root Valley the areas in which more or less heavy second growth has followed the removal of the original timber have been found to be most heavily infested with ticks. These areas are locally known as “slashings.” (See PI. I, fig. 1.) It has been determined that the direct rays of the sun during the summer have a markedly injurious effect upon the early stages of the tick. This fact may be utilized to some extent, as will be shown later, in the control of the species by clearing the land of timber and under- brush. In small experiments it has been found that when the seed ticks are exposed to the sun during very hot weather they imme- diately crawl down the grass to the surface of the soil to seek pro- tection, and in the absence of an abundance of moisture death results in a very few days. The exposure of freshly deposited eggs to the sun at Dallas, Tex., has been found to cause them to shrivel and dry within less than a day’s time. The relative abundance of rain, especially during the spring months, in different years has a marked effect upon the number of ticks occurring in a given locality. This factor is of little importance in the natural control of the adult stage of the tick, but is a potent factor in the destruction of the eggs and immature stages, particularly after the latter have become engorged and dropped from the animal. Several other natural means of control of minor importance are also operating to some extent to keep the species in check. In barn lots, chickens have been observed to destroy the females which drop to the ground after becoming filled with blood. Some wild birds are known to feed upon various species of ticks, and in one instance, at least, they have been observed to destroy the engorged females of the spotted-fever tick. Certain species of ants are also thought to be im- portant enemies of the pest, particularly when the ticks are in the ‘immature stages. Owing to the fact that the Rocky Mountain spotted-fever tick is primarily a northern form, and therefore accustomed to severe cold, it is doubtful whether severe winters are of much importance in its destruction. This is particularly true where there is an abundance of protection provided by brush and litter on the ground, SUMMARY OF LIFE HISTORY. 19 SUMMARY OF LIFE HISTORY OF THE SPOTTED-FEVER TICK. As is the case with nearly all species of ticks, this one passes through four distinct stages, namely, the egg, the larva or seed tick, the nymph, and the adult. « THE EGG AND LARVA. The eggs (PI. II, fig. 5) are small, ovoid, brownish objects, about one thirty-eighth of an inch long. These hatch into minute, light brown, active six-legged creatures known as larve or seed ticks. (Pl. III, fig. 2.) Before further development takes place it is neces- sary for these seed ticks to feed upon the blood of some animal. They usually attach to small mammals, such as ground squirrels, and become filled with blood in from 3 to 8 days. They then drop off the host and find a convenient protected place in which to continue their development. Before engerging the seed tick measures about one thirty-seventh of an inch in length, but during feeding the body is considerably distended, so that it measures about one-eighteenth of an inch in length by one thirty-first of an inch in width when en- gorgement is complete. The color of the larve when engorged is slate-gray. Activity is greatly reduced on account of the weight of the blood imbibed. THE NYMPH. a After a resting period cf from 6 to 21 days the skin is shed from the body of the engorged seed tick and an active eight-legged nymph appears. The extra pair of legs is gained during the resting stage. This character is sufficient to distinguish the nymphs from the pre- ceding or larval stage. In this stage it is necessary for the young tick again to find a host and fill with blood. This feeding period requires from 3 to 9 days. When engorgement is complete (see PI. II, figs. 3, 4), the nymphs measure about one-sixth of an inch in length, while before engorgement the length is usually about one- seventeenth of an inch. The engorged nymphs are bluish gray in color and not very active. : THE ADULT. As in the case of the engorged larvee, the nymphs, after dropping, seek a protected place in which to transform, and there become com- pletely inactive. This resting stage requires a longer period than the preceding. During this time the sexual organs of the ticks de- velop. When the skins are shed the ticks appear as mature males and females. Shortly before the molting of the nymphs the lght- colored shields on the back of the adult ticks can be seen through the thin skins which are soon to be shed. After the mature ticks es- cape from the nymphal skins they are rather soft and comparatively 2°20 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. inactive. They soon become dried out and the external structures become thoroughly hardened. The color pattern becomes more pro- nounced and activity increases. This is the stage in which the ticks are ordinarily observed in the spring months. The males (PI. II, figs. 2,4) and females (PI. I, figs. 1,3) are nearly the same size, but the former have a hard plate or shield covering the entire back. Upon this shield is a somewhat complicated pattern formed by white bands or stripes. In the female the shield is much smaller, covering only the anterior portion of the body. Almost its entire surface is covered with white. The portion of the body of the female behind the shield is rather soft and elastic. It is usually somewhat wrinkled and of a dark reddish-brown color. In this stage, as well as in the preceding, the ticks have eight legs, but the white markings on the backs of both sexes and the presence of a small genital opening on the underside near the “heads” of the ticks serve to distinguish them readily from the other stages. Of course the size of the adult ticks is considerably greater than that of either of the immature stages. Prior to feeding they usually measure about one-sixth of an inch in length by one-tenth of an inch in width. Before reproduction can begin it is necessary for both the males and females to feed upon the blood of some animal. They usually attach to the large domestic animals, and after feeding about 4 days or more the,males start in search of mates. Fertilization takes place on the host, and in from 8 to 14 days after attachment the females, having become filled with bleod, drop from the host and seek a protected place in which to deposit their eggs. During the course of feeding the portion of the body of the female behind the shield is greatly distended, so that the specimens now measure about one-half inch long by one-third inch wide by one-fourth inch thick. On account of the enormous distention of the back part of the body of the female, the legs and head are rendered inconspicuous. A close examination, however, will show the white shield on the back just, behind the “head.” When the females are filled with blood the back, part of the body is usually a bluish-gray color. Although the males imbibe a certain amount of blood when attached to an animal they never increase greatly in size as do the females. The females always drop from the host animal before beginning the deposition of eggs. Deposition continues for about 380 days, during which time several thousand eggs are deposited. (See Pl. I, fig. 5.) During the process of deposition the female gradually shrinks in size. When all of the eggs are expelled the tick.is much shriveled (Pl. ILI, fig. 1) and has changed in color to a mottled yel- lowish. She dies within a few days after the last eggs are deposited. While depositing her eggs the female remains in the same place, so that all of the eggs are in one large mass. The eggs hatch into seed ticks in from 16 to 51 days and the life cycle is again repeated. Bul. 105, Bureau of Entomology, U. S. Dept. of Agriculture PLATE II. THE ROCKY MOUNTAIN SPOTTED-FEVER TICK (DERMACENTOR VENUSTUS). Fig. 1.—Adult female, unengorged, dorsal yiew. Fig. 2.—Adult male, dorsal view. Fig.3.—Adult female, unengorged, ventral view. Fig. 4.—Adult male, ventral view. Fig. 5.—Adult female in act of depositing eggs, (¢ riginal. ) Bul. 105, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE III. THE SPOTTED-FEVER TICK (DERMACENTOR VENUSTUS) AND DERMACENTOR ALBIPICTUS. Fig. 1.—Adult spotted-fever tick which has deposited eggs. Fig.2.—Larva of spotted-fever tick. Fig. 3.—Engorged nymph of spotted-fever tick. Fig. 4.—Same, ventral view. Fig. 5.—Adult maleof Dermacentor albipictus. Fig. 6.—Adult female of ). albipictus, unengorged. (Original.) ¢ SEASONAL HISTORY AND HABITS. St SEASONAL HISTORY AND HABITS. For convenience in tracing the life cycle of the Rocky Mountain spotted-fever tick we will begin with the appearance of the flat or unengorged females and males which appear with the first warm days of spring. It should be remembered that these ticks have remained dormant throughout the winter months. When they are rendered active during the warm spring days they are immediately ready to attach to an animal and engorge. Some of these ticks pass the winter in places where they are not readily reached by the warmth of the sun. Such specimens become active later than others. Emergence from winter quarters is therefore gradual, usually extending over a period of a few months, beginning about. the 1st of March. The time of the beginning of activity in the spring is also depend- ent to a considerable extent upon the relative earliness of the season and upon the locality. In lesser altitudes, and at the southern limit of the range of the species, activity may begin as early as the middle of February, while in the Bitter Root Valley it is probable that the ticks seldom become active in numbers before nearly the middle of March. After leaving their winter quarters the adult ticks begin crawling about and usually ascend brush to await a host. They may crawl upon trees or other objects so as to get several feet above the ground. In all ticks the anterior legs have well-developed sense organs located near their tips. These front legs are used as feelers. When the tick is disturbed it immediately begins to wave them in an endeavor to catch any passing object. Having found a host, the ticks crawl about upon it until a suitable place for attachment is found. On cattle they are usually found in numbers on the dewlap, between the fore and hind legs, and along the belly. On horses they are commonly found between the legs and sometimes in the mane. They may, however, attach to any part of the host. Attachment to the host is accomplished by means of a spiny beak, which has an opening in the end through which the blood of the animal is drawn. In from 4 to 8 days after attaching the -males begin searching for mates. In order to fertilize the females they crawl beneath them, and after mating usually attach to the animal immediately under their mates. When the females have become one-half engorged the blood is rapidly imbibed, and com- plete engorgement is reached in a very short time, after which they loosen their hold and drop to the ground. Table I shows the time required for the engorgement of females on different hosts and during different times of the year. 22 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. TABLE I.—Time required for engorgement of females of Dermacentor venustus at Dallas, Tex, ae Dates of dropping as Adults attached. engorged females. Period of engorge- ment. Date. Host. First. Last. Days. May 15/1008 || Ome. ..o 2022 St May 23] June 1 8-17 Mar. 19,1910 | Guinea pig....}] Mar. 28] Mar. 28 M) Aspire? HE; TOU0.| Omer her. ce Apr. "2 apr. 3 11-12 May east Glo Oxi ase May 12; May 17 8-13 Mar. 29,1911 | Ox.__.... ee Vl 813i Apr. 12 9-14 May 29,1911!) Goat.......... June 3} June 15 5-17 | The specimens in this lot were fertilized and slightly engorged when applied. After the dropping of the females the males usually remain on the host for some time. We have found that they crawl about over the animal, reattaching in different places and fertilizing a number of different females after one infestation of females has become en- gorged and dropped from the host. Immediately after leaving the host engorged females endeavor to find some protected place in which to deposit their eggs. As has been stated, deposition may begin as soon as the seventh day after dropping, and all of the eggs, which usually number about 4,000, are deposited within 30 days. During the process of egg laying the female gradually shrinks in size and death takes place within a few days after all of the eggs have been laid. The length of time before the beginning of egg laying depends largely upon the temperature. During cool weather a period of 41 days has been known to pass after dropping before the first eggs were deposited. The development of the seed tick begins within the egg as soon as it is deposited. After the embryonic tick has grown for about two weeks, a small white spot appears on one side of the egg. The appearance of this spot enables one to determine whether the eggs will hatch. The time required for incubation is largely dependent upon temperature conditions. In the Bitter Root Valley Mr. W. Y. King has determined that this period ranges from 34 to 51 days, the longer period occurring in the early spring months. At Dallas, Tex., we have observed eggs to hatch as early as 15 days after they were deposited, the longest incubation period observed in that — locality being 41 days. After the small seed ticks hatch from the egos they usually remain clustered upon the eggshells for a few days and then crawl upon any object in their immediate vicinity to await a host. In this stage also the front legs are used as feelers, and when an animal comes into contact with the seed ticks, these immediately catch hold. Naturally during the larval stage, as well as during the adult stage, large numbers of the ticks starve before finding a suitable host upon which’ to engorge. The larve die much sooner from starvation than do the other stages of the tick. SEASONAL HISTORY AND HABITS. 28 During the summer months we have found that all of the seed ticks hatching from a mass of eggs usually die within one month after =} ta) the first eggs hatch. In one instance a period of 117 days elapsed between the beginning of hatching of the eggs and the death of the t=} > oS t last seed tick. This is the greatest longevity which we have observed. Table II indicates the variations in the time required for the be- ginning of egg laying, incubation of the eggs, and length of time required for the starvation of the seed ticks: TABLE II.—Time required for beginning of deposition of eggs, hatching, and starvation of seed ticks of Dermacentor venustus. Period Period Period ed from drop- from be- Date | from be- ere famiale Date first ping of | phate hatching| Simning of| all seed | ginning of ‘erie dropped or eggs were de- | female to of eggs began. deposition ticks | hatching to rei ee. din was picked posited beginning *| to begin- were death of ine from host of de- ning of dead. last seed cubation F position. hatching. tick. si 5 Days. Days. Days. Mp June 11,1909 | June 27,1909 16 | July 15,1909 18 | Sept. 5 52 91.8 Mar. 28,1910} Apr. 7,1910 10 | May 10,1910 33 | July 25 76 70. 49 Apr. 2,1910! | May 13,1910 41 | July 3,1910 51 | Aug. 1 BO) Ea Beare Apr. 7,1910 } Apr. 17,1910 10 | May 19,1910 32 | July 19 61 74.6 Apr. 13,1910 | Apr. 20,1910 7 | May 25,1910 35 | Aug. 15 82 71. 78 Apr. 26,1910} May 2,1910 6 | May 31,1910 29 | July 30 60 71.55 May 1,1910! | May 19,1910 18 | July 9,1910 51 | Sept. 3 il FEB aeeees see May 14,1910 | May 23,1910 9 | June 12,1910 20 | Aug. 31 80 79. 64 May — 1910! j..... doteeeeeelo =. sees see July 9,1910 47 | Nov. 3 DG ELE cactincess June 4,1910 | June 13,1910 9 | June 29,1910 16 | Sept. 29 92 84. 37 June 4,1910! | June 17,1910 13 ql 2 34 | Aug. 11 7 il ee eee efore July 16,1910 | July 25,1910 9 | Aug. 10,1910 16 | Sept. 30 51 84. 59 1 These records were made in the Bitter Root Valley in Montana; all others were made at Dallas, Tex. Those larvee which succeed in finding an animal upon which to engorge usually attach about the head and ears of the host, be- come filled with blood, and drop from the animal between the third and eighth days. In nature the larve feed almost entirely upon the small wild mammals, although experimentally they have been forced to engorge upon cattle. As has been stated, the larvee after becoming engorged drop from the animal, find a protected place, shed their skins, and become active eight-legged creatures known as nymphs. These nymphs emerge from the quiescent seed- tick stage from about the middle of July to the beginning of cold weather. Some of those transforming during the summer find hosts, become engorged, and drop for molting. A few of these probably molt to adults before cold weather begins and hibernation takes place in the adult stage. These few individuals are the only ones which complete their life cycle in a single season. It should be emphasized that these nymphs, as well as the seed ticks, feed almost exclusively on small wild mammals. Tables ITI and IV show the length of the engorgement and molting periods of larve and nymphs. = 24 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. Taste III.—Time required for moliing of seed ticks and nymphs of Dermacen- tor venustus. Seed ticks dropped| Date seed ticks Period Nymphs dropped Date nymphs Period engorged. molted. from engorged. molied. from dropping |) dropping to to Date. | Number.| First. Last. molting. || Date. |Number.| First. Last. molting 1908. 1908. 1908. Days. 1908. 1908. 1908. Days. Apr (5 23 | Apr. 20} Apr. 24 15-19 || Aug. 6 17 | Aug. 20 |} Aug. 22 14- 16 1909. 1909. 1909. May 17 15 | May 27 | May 30 10-13 || Sept. 15 5} Aug. 6] Aug. 7 21- 22 . 1909. 1909. 1909. 1910. Aug. 6 7} Aug. 13 | Aug. 16 7-10 || Oct. 3 3 | Oct. 21 | Mar, 22 18-170 . 1910. 1910. Sept. i 56 | Sept. 7 | Sept. 10 6- 9 || Mar. 23 2| May 4] May 23 42- 61 1910. 1910. | 1910. July 4!) Many.| July 18) July 25 14-21 || Apr. 14 13 | May 24] May 30 40- 46 July §8!| Many. | July 19 |_..do..... 11-17 || July 21 1] Aug. 1] Aug. 1 11 July 221 Many. | Aug. 8 | Aug. 11 17-20 | Aug. 1 6 | Aug. 14] Aug. 16 13- 15 1911. 1911. | _ 1911. May 22 110} May 30 June 2 8-11 || Aug. 19 12 | Aug. 31 | Sept. 4 12- 16 ! These records were made in the Bitter Root Valley, Mont.; all others were made at Dallas, Tex. ’ TABLE I1V.—T'ime required for engorgement of seed. ticks and nymphs of Der- macentor venustus. Date of dropping Date of dropping Seed ticks applied. as engorged seed | period Nymphs applied. as engorged | period ticks. of en- nymphs. of en- gorge- gorge- ment. ment Date Host. First. Last. Date Host. First Last. 1908. 1908. 1908. Days. 1908. 1908. 1908. Days Apri 2 wOx cde. 22 Apr. 5] Apr. 10 3-8: MADE. lal Oxmo sa ores Apr. 5] Apr. 8 1909. 1909. 1909. daly 12s cee doy23 32. July 15) July 18 3-6 || Aug. 13 | Guinea pig.| Aug. 17 | Aug. 18 45 1909. 1909. 1909. July 28 | Guinea pig.|} Aug. 2| Aug. 4 5-7 || Sept. 10 | Rabbit.....) Sept. 14 | Sept. 15 4-5 1910. 1910. 1910. Aug. 2] Rabbit.....| Aug. 7} Aug. 7 5 || May 24] Bovine.....| May 30 | May 30 6 Aug. 27 | Guinea pig.| Aug. 29 | Sept. 3 27 || Aug. 13 | Rabbit.....) Aug. 18 | Aug. 20 5-7 1910 1910. 1910. July 191 pitied a July 22] July 23 3-4 || Aug. 19 | Rabbit.....| Aug. 23 | Aug. 28 49 squirrel. - 1911. 1911 1911. f May 18] Guinea pig.| May 21 | May 24 3-4 || Aug. 172} Ground | Aug. 22} Aug. 27 5-9 | squirrel. 1 This record was made by W. V. King in the Bitter Root Valley, Mont. on July 21, or the second day after application. 2 This record was made in the Bitter Root Valley, Mont. made at Dallas, Tex. Dropping probably began Records not referred to in footnotes were Those larvee which hatch from eggs deposited by females which do not find hosts until late in the spring become engorged during July and August and do not molt to nymphs until shortly before winter. It is thus necessary for the nymphs which appear late in the summer to pass the winter in that stage. These nymphs appear in the spring shortly after the emergence of the adult ticks; that is, shortly after the middle of March. They continue to emerge from SEASONAL HISTORY AND HABITS. 25 their winter quarters for some time, the last individuals not securing hosts upon which to engorge until early in July. These individuals molt to adults during the latter part of the summer, and the resulting adults pass the winter before feeding. In contrast to the short length of life as exhibited by the larva, we find the vitality of the nymphs and adults to be remarkably great. It has been determined that adults collected on vegetation during the spring months may survive for a period of 413 days without food. These individuals undoubtedly passed the winter in the adult stage, and therefore the total length of life must have been approximately one and two-thirds years. However, in nature the great majority of the ticks with a vitality equal to this lot would probably find hosts and become engorged. Unfed nymphs have been found to survive a period of more than 300 days. It is thus possible for ticks which pass the winter in the nymphal stage to live until at least July 15 of the following year. Under natural conditions this longevity is probably even greater. The following is a summary of the life cycle of the tick: The winter is passed as flat or unengorged males and females and as un- engorged nymphs. The former are present from about March 15 to July 15, during which time they find hosts and become engorged. It is during this period that the pest attacks man and communicates to him the germs of Rocky Mountain spotted fever. The eggs de- posited by the females which find hosts early in the spring hatch into larve, which may develop into adults by the first or middle of September. The offspring of the females which become engorged late in the season succeed in developing only as far as the unengorged nymphal stage before cold weather begins. The overwintered nymphs begin appearing from their winter quarters during the latter part of March. They are to be found upon small wild mammals from that time until about the middle of July, at which time the nymphs which have developed from the females engorged during that spring are also present. Overwintered nymphs transform to adults during the summer and fall, and the majority of these adults pass the winter in the unfed condition. A few of the first nymphs to find hosts early in the spring may molt to adults sufficiently early in the summer to allow the adults to become engorged, deposit eggs, and the transformation to proceed to the unfed nymphal stage by the appreach of cold weather, thus completing a life cycle in one year. However, the individuals which proceed with development beyond the unengorged adult stage during the same season must be very exceptional. When the mean temperature is low during the spring and early summer it is almost certain that none of, the individuals which have passed the winter as unengorged nymphs develop further than unengorged adults during that season. 26 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. It has been observed that even though the adults which transform from overwintered nymphs are kept confined with the host animal during the summer or fall following their maturity, they show no marked desire to feed, usually endeavoring to crawl away and be- come quiet. Thus the habit of the adults of attaching to hosts in the spring appears to be so well established that they can scarcely be induced to attach to a host after midsummer. From the foregoing statements it is evident that although a few of the ticks may complete their life cycle—that is, the transformation from unengorged adults to unengorged adults of the next generation, or from unengorged nymphs to unengorged nymphs of the next gen- eration—during one season, the majority require two years for this eycle. Should overwintered nymphs not find hosts until late in the season and thus not become adult until the approach of winter, the resulting adults, if unable to find hosts, may survive until the second spring following. Ticks which pass the winter in the adult stage may survive until the second spring following, then engorge and pro- duce offspring which develop to nymphs the second summer, pass the winter in the nymphal stage, and complete development to unen- gorged adults during the third season. Thus it is apparent that under certain conditions three years might be required for the com- pletion of the life cycle. This would necessitate the destruction of the adult ticks during three successive seasons in order to eradicate the species. Figure 2 shows several of the ways in which development may proceed. THE HOST ANIMALS OF THE SPOTTED-FEVER TICK. The investigations conducted by Dr. Ricketts indicated that the Rocky Mountain spotted fever tick is restricted in regard to its host relations. Our investigation has shown that this restriction of certain stages of the tick to certain classes of animals is very well marked. Zhe examination during three seasons of nearly 800 wild mammals which are inhabitants of the Bitter Root Valley and numer- ous observations made elsewhere have shown that, with few excep- tions, only the immature stages of the tick are to be found on this class of hosts. On the other hand, the large domestic animals are the principal hosts of the adult ticks, and the immature stages are rarely, if ever, found upon them. This restriction of the adult stage to the larger mammals, now a firmly fixed habit of the tick, undoubt- edly arose from the fact that the adult ticks are so large that they can be easily removed by the smaller mammals. As will be pointed out in the discussion of remedial measures, this habit of the Rocky Mountain spotted-fever tick may be taken advantage of in the con- trol or eradication of the species. 27 SEASONAL HISTORY AND HABITS. ‘aoA0 oftT ou ajofduroo 01 saved earyy Ssulmber snqy ‘syudurdu posiosu0un 0. UOS -Bas 18Y} Sulpseoid yuour -dojeaep ‘sulids puovses ey} [jun os10s8ue Jou op puesjsoy puy 0} [BJ SIOTIO “QjoAO djl] oY} VJaTduLOD 0} saga OM} SuULIMbel snyy ‘1e0A SULAMOTIO} OY] SHCA 0} WHOysueI} SYN itd su ~jmsoi oy} pur ‘s3z0 yIsod -ap ‘es10s00 esol} JO ouI0g “rea ou0 uw ydurdu poesiosuoun 0} ydurkt posiosueun ur0lj =) ye) aT] Ou 9j0]AuI09 asotL,L, -ur0d 03 sivak omy Sump -o1 sny} ‘Surids SuLMoyjoy a} JJOUL PUB 95105 SOT, “sype pasi07 -ueun 0} sy]npe pasiosueun wolf eJOAO at] oY} o07duL0D 0} 1eed ouO ynq oMbes oso, ajo Ao ajIT eq oja;duroo 04 ‘sivah va1q} eltnbai oseyy “s}pe poesiosueuN se Jo}UTM oY ssed puy “S¥OT} poos s@ 1oJULM SUIIMp op JO yoVeY 04 IB} Joye ssd0 poytsodep-10}ze] oy, “9884S SIU} UT Jo] UTA 93 ssed YoryA sydurku 07 {jour pus os10300 BAIv] ey} pus Yo.ey Jolie oy] Jo Moy VW “1OPUTM OY SULINP VIP PUB BAIL] pesiosue 10 pe510SMOUN SB 10] UIM df} 10} U9 VSOT ‘sydumAu posi0ste SB Jo,ULM 04} ssed pure osi0sue Avur Mo B Jo sydurdu pes1OFUOUN SB 1OJULM Oty ssed osoyy, ‘syduAu poesiozsmeuN se 19jUTM oT} ssed eso, ‘sydurAu posiosu0un se 10} ULM oy} ssed ynq pooj you op Ayrs0lvur oy, “sy[Npe pos103 -WeuN SB JOJUIM oY} ssed gsoty, “HWes_ OU} UT si[npe 0} Jour pues esi1osue Avur sydurAu osoyy Jo Moy V “JOUIUINS SUTMOTIOJ 9} SI[Npe 0} [OWL pUB 93103 OSOTL “you saaaf-payjods umjunoyy hyooy ay7 fo huojsry youosvas aqissod ayz bunoys wosboig—'Z *PIyy *1OUIUINS 94} JO 4S01 ay} sump yomb ureuroy *s330 yIsodop pie Jour -UMS UI 98.1050 ABUT Moy VW “TLBJ oY} Ul 92810300 10 posi03 -uemM UIeUIel Moy AIOA VW “TTey Ajava 10 JouLUMs 94] ul sydurtu 0} 4jour pue es10300 SOI} poos omMug “IOUS 078] Ur syduAT 0} {[OUL PUB 951039 SIOTI.O *JOWUIMS Pru Ul sydurAtt 07 4jour pues adios Syl} pooas ourog ‘aseys YBq} UT Jo,UIM oy} ssed pue uos ~eas yeu, sydurdu poesi03 -ueun 0} dojaaAep ose “T1®} Jo JoWUIMS 9), Ut S}MPB 0} FOUL osotyL, “IOUIUINS WI pos103 “Wa 9ul0deq si0T1O mG )eegorgats) Ajyieo 10 3utids ut “Butids ur pos.103 SJ[NpB 0} JOU BSey,T, -Wd s9UI0D0q sULOS *ovuUMNs “IOUIMIMS 948] 10 Ajivo pure suiids PIul UE Yoyey osey} aye] Wl poadi03 Aq payisodep ss38q -Ue ouUI0D0q si0TO *“IauTuUINs “sutads Ajieo Ul Youey bag uw Ajivwo pos103 Aq poysodep sasq -ue oulod0q oUl0g “Sutids puo “aos | 098 oY} S830 yIsod -vas Surmorjoy oy} -ap pue as103u0 yng o93103Ua 0} [Tey oul0g “sydursu p 9 s103 000) “synpe po 3103u0eu-, *S[@NprATpUr Polo} UTA IOAG 28 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. Among the demestic animals which act as hosts for the adult stage of the tick, horses and cattle are of prime importance. A number of collections indicates that sheep are frequently attacked, but with smaller numbers of ticks. Dogs have also been found to harbor this species, but in limited numbers only. Among nearly 100 collections of ticks made on dogs in the territory in which this species occurs only 12 lots of this tick have been obiained. Only 2 of these 12 lots contained females which were sufficiently engorged to deposit eggs. This indicates that the majority of the ticks are scratched off by the dogs before becoming fully filled with blood. Mules and asses have also been found infested with this species, and in two instances collections have been made upon hogs. It is not likely that the latter host is of much importance, particularly when the animals are kept confined in pens and thus not exposed to the ticks. Among the wild animals which act as hosts for the adults, the mountain goat harbors by far the greatest number. In addition to specimens of the adults, nymphs have also been found upon them. The brown bear and coyote have been found to be infested with considerable numbers of spotted-fever ticks, some of the specimens being sufficiently engorged to deposit eggs. The snowshoe rabbit and jack rabbit have occasionally been observed to be infested with limited numbers of adults, but on neither of these hosts have en- gorged specimens been captured. The woodchuck has also been found to act as a host for the adult stage. In only one instance, however, were specimens taken upon this host, although 51 of the animals were examined during the investigation. The Columbian ground squirrel is undoubtedly by far the most important host of the immature stages of this tick in the Bitter Root Valley. In other parts of the Western States, where this species of ground squirrel does not occur, related species have been found to act as hosts for both of the immature stages of this tick. In the Bitter Root Valley 65 per cent of the 341 Columbian ground squirrels examined were found to be infested with immature ticks of the genus Dermacentor. Owing to the fact that very large num- bers of the immature stages of ticks belonging to the genus Derma- centor collected in the Bitter Root Valley were reared to adult and all found to be the Rocky Mountain spotted-fever tick, we can say with practical certainty that this is the only species of this genus which occurs on the small mammals in that locality. Second in importance as a host of the immature stages of this tick in the Bitter Root Valley is the yellow-bellied chipmunk. Thirty-seven per cent of 131 of these mammals which were examined were found to be in- fested with seed ticks and nymphs. The pine squirrel is also of much importance, as 29 per cent of the 181 mammals examined. were in- 29 *(pvop) oyeUr T 9 *podeoso SIoy}O Moy WY “SoTVUIE] ST ‘SaTeUr eT ¢ *So[VULO] G ‘SOTLUL F 5 0 0 0 9 0 0 0 0 0 o I T9 0 0 0 0 0 0 0 0 0 “A]LYSrS 0) posi0sueu yj COT €¢ £&¢ “Y}Inoj-ou0 0} ATYSITS 0°81 &T &l+ *pesi03 Te Al[ny 0} poasiosueug | +0-00r | +008 +008 0 0 0 a * 0 = 0 0 0 0 0 0 s 80° I 0 = 0° | 0 : I 0 a Go" I 0 €8° SF 0 a OF" 02 0 B 6° ST 0 “GJUGASS-0UQ | 0S "T 9 er an) G2 °T 0% 0 oL°S T&T 0 ‘uss | 62°8 068 g ¥'E | +98¢ 0 13°F 66 0 60°9 $10 °% 0 ee Mag | ‘wien | simpy |suduty *So[BOIe 4[Npe jo JUsULEsI0ZU—a Jo 314R1g *poururexe SUIAq OL0Joq 4Soy e1OM AO, ‘*snyjordiqye -q yo sydurdu uoeq oABY ABUL CSOT, “mus ¥ ¢ ‘S[CUNUB off} 4Jo] OAVY ABUT SHOT} CULO *pouyUIexe Suleq o10Joq Pop [BIAS g “O[BULeJ [ ‘Soeur Z 7 *punoy s¥or} JaAaj-payjods jo Jaquny oecooooscos oD coomooo oO oo mae oe ofS oS bas | a aaa Sf She SSS oooocoecoo 5 on) an HRAGBA WiSAnNdar~mascoooceos so a HOt tr onOOoOCoCoCO MINOSIWOS HAHOOCCOCOCOM FNOCONHnOCCSO oor al rm tol ke ° N IIH Mr4 WOMOOMOMOM oD O19 SBaa OD NAD AD Oran “SYOT} JoAoy UIT paysay | SF ToAey speumue jo | f° equ (Ri ae ig PO Ee ial BPIUONMIOdsaA |" °° °7 52°72 -s ee sene “""syBq Fit = irgey ee ge ae ae) SNOMYOqI2 Ieqtyp |-" >= <5 75> sess - =<" “ZBDISNYL heen bcm S[SMOMOZTIB SNEIOING |" "°°" Tete tess ee TOSBO MA en oe SHER] BOPEOUT, |" 527 R42" “eas Jos peg Veet abe oe omnes os SISUOPBUBO SMATOD |" "°° noone c ote scwe see we lc! alae oy aed ROTC SnIMONg] SNeftooopg |" **-*- "7-7 ** Joep polley-ory Oo Bet = fers Snuolurey SNoflod0pO }**"* "77777 Joep eT Ee ap [rn mierlateraiala etstainlaiei= REISE USLUS ES 255 teen to eee 930409 LT [trcteceseees SNUBO]IOUTG SNSIQ) |-°*"- 7-7-7" 7 tooo qeoq UMOIG e ap ages “snuejuour soummReIQ |*""-"*7 777777 qeos Urey UNO Olas Dike eae oe eee cae hj «COTS fl bigs ele ea tai a ee SMorys a ooo snurdye snseydoanjog |***** "7-777 77+ jernbs surApy Fi Se Nester Se sisueoyepl SAUIOJOA |-7 "77777 OSNOUL PoxoVq-poy z era suessouvo *U snjororyy |-**** ***"@SNOUL MOpvaUT ABINH ( een Re SOG cre XBP1OUL SNYOIOIPY |°~“OSMOUL MOpvour paTie|su0T Ais We wasp ge “"snosny shulounoyy, |-""""" 77° Joydos yoyo Tae. ogi “--***sdeourid euojoyog |°**"***- “Hqqei Yoo! 10 VAT DT es th ser oe eoaS “*sdeoulid sndez |-*"°*-*-*7-7** esnoum surdume ze Crete *“Snjsopour SnyoJoryy |***~ ~*~ “eSnOUE MOpvOUL os.rerT 8G... |csse-*- snuriquin *b sermueyngy |* ~*~“ yunurdryo perjjeq-e11q A 0g ~*""@ISTUIOJIB “Ur SnosAuIOleg |"*""*"*" 7" OSNOUL p9}0oj-oy1T oT Se ea Ty1eq4NU snsepAyAg |------ eer HAeI [181107409 Bee see mci tieeeee Ipareq sndayT |**""*----*-*-41qqei soysmoug OT ae eee “°° °B9@JOUIO BULOJOON |°"-* "7777" soos 48 POOM *suos oF ~eiouro *[T ~sntydourredsojyeg |--jormMbs punois podrays-epig Lye aleaaine Sees JO}USATACY BjouLey |--*" "7777 *"xonyqopoo M [Es Rea oe Tuospreyors “y snampog |** 7" 7" 7°" ha 4: Lees Soke Tel “**"*sra}meaTeyNy “q serureyngy |-77*° yUMMUdrYyo per[eq-MoyaX Toes aie ee snueiqumjoo snijo}19 |***Jel1mbs punois uviqumyog *pourure ae: ‘saureU OyTUEIOg ‘soured WoUrUIOD Jaquinn Sera ee ee ee eee es ee “uooiayy punof snisnuaa sojuanusag fo sabvjs pun wwqunu yn ‘T-016I Buninp fiayoA Jooy INT ay) Ur prunuyx9 sppuwmnw pyiy7— A AAV, 30 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. fested. Among the other mammals which are of considerable impor- tance as hosts of the immature stages are the large chipmunk, the woodchuck, snowshce rabbit, rock squirrel, wood rat, white-footed mouse, and meadow mouse. Our knowledge of the tick hosts in the valley was greatly increased by the cooperation of the Biological Survey of this department. Messrs. Howell and Birdseye, of the Survey, were located at the camp laboratory and made extensive collections during 1910. This work was continued in 1911 by Mr. Birdseye. Table V furnishes a list of the wild mammal hosts of this tick. It includes all the records of the Biological Survey,’ as well as a number made independently by Mr. King, of the Bureau of Entomology. The mammals are listed in the table according to their relative importance as hosts of the im- mature stages. It is especially worthy of note that among the wild mammals which act as hosts for the adult stage the mountain goat and brown bear are the only ones which were found to have ticks upon them which were engorged sufficiently to deposit eggs. One hundred specimens of the birds commonly found in the valley were examined and found to be free from ticks. TABLE VI.—Host animals on which Dermacentor venustus in the adult stage has been found. ON DOMESTIC ANIMALS AND MAN, Approxi-| Approximate number of mate ticks collected. sas number State of engorgement Common names. Scientific names. Giiosts oftifernales. exam- ined: Males. | Females.| Total. Ox rank ashok ome BOS TAWNUS te oe 200 | 2,000 2,000 | 4,600 | Unengorged to fully. HIOTSGe. cheach ace ces Equus caballus...... 800 | 2,500 2,500 | 5,000 Do. TASES Soe eee Equus asinus.....---. 5 9 5 14 Do. Male vee 2. = ze Se Equus asinusX cabal- 9 14 17 31 Do. lus. Sweep Eos. wee as os Ovis airlesaes 3 Ay 75 22 32 54 bee ees to one- half. 1D Jaf eee pe ee es Canis familiaris...... 100 18 29 38 | Unengorged to three- fourths. ORG et ea ees ees Capra hireus. ...25. -. 5 0 4 4} Unengorged to slightly. HO. ie sh. 60s eee Sus serofac 2.5.5: 5. 10 2 4 6 ao to one- third. Man bets. choses Homo sapiens..-..---- - 900 400 400 800 ee aie to one- fourth. Domestic cat... ..-- Felis domesticus... .- 1 1 9 1 | Unattached. ON WILD ANIMALS. Mountain goat..... Oreamnos montanus. 3 150 150 300 | Unengorged to fully. Coyotet smite Canis lestes.........- 1 15 16 31; Unengorged to slightly. Brown bear........ Ursus americanus... 1 4 9 13 | Slightly to one-fourth. Jackrabbit......... Lepusispen.. sascsees 15 3 6 9 | Slightly to one-sixth. Woodehuck.......-. Marmota flaviveniter. BL], Dares 2or3 5 | Slightly. Snowshoe rabbit...| Lepus bairdi........- 4 2 1 3 | One-seventh engorged. MUA cat 2064.2 Liynswints.. 22. +562 2. 1 1 0 1 adr. ots Su ee Taxidea taxus...-..- 4 21 0 1 vee vee States Department of Agriculture, Biological Survey, Cir. No. 82. ead. OTHER SPECIES OF TICKS. 81 ; OTHER SPECIES OF TICKS FOUND IN REGIONS WHERE ROCKY MOUNTAIN SPOTTED FEVER OCCURS. Five species of ticks other than Dermacentor venustus have been found to occur more or less commonly in the Bitter Root Valley of Montana. These are: Dermacentor albipictus Pack. (P1. IIT, figs. 5, 6), Ixodes angustus Neum., Jvodes texanus Banks, Ixodes kingi Bishopp, and Haemaphysalis leporis-palustris Pack. On account of the host relations of these ticks it is impossible for them to play any important part in the dissemination of Rocky Mountain spotted fever. Dermacentor albipictus has been found to occur on practically no other animals than horses, cattle, and mountain goats. It never attacks man. Neither one of the three species of Ixodes has been found to occur on man, and they very seldom attack the domestic animals, being confined to certain of the small wild mammals. The last-named species confines its attack exclusively to rabbits with the exception of the immature stages, which are occasionally found upon birds. In parts of Idaho, Oregon, Nevada, and Utah, the rabbit Derma- centor (Dermacentor parumapertus marginatus Banks) is found quite commonly. Like the other common rabbit tick this species con- fines its attack exclusively to that host. SPECIES OF TICKS WHICH MIGHT PLAY AN IMPORTANT PART IN THE DISSEMINATION OF THE DISEASE SHOULD IT BE INTRO- DUCED INTO NEW REGIONS. Since it has been shown by Dr. Maver, of the University of Chicago, that Rocky Mountain spotted fever may be transmitted by several different species of ticks, the importance of limiting the disease-infested area to the territory now covered is strongly em- phasized. A closely related species, namely, Dermacentor occidentalis Neum., has been found to occur throughout western California and south- western Oregon. At present the range of this species does not over- Jap that of the Rocky Mountain spotted-fever tick. On account of the fact that this species is an important pest of man, should the disease become introduced into the territory where it occurs its dis- semination would be certain. In the eastern and southern United States several species occur which commonly attack man. Nearly all of these have host relations very similar to that of the Rocky Mountain spotted-fever tick, and therefore the disease might readily be transmitted from animal to animal and from animal to man by any of these species. The following species would probably be ef principal importance in the Southern and Eastern States: The fone-star tick (Amblyomma americanum L.); the American dog . tick (Dermacentor variabilis Say), and the gulf-coast tick (Am- blyomma maculatum Koch). In the extreme southern portions of 32 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. Texas and New Mexico the Cayenne tick (Amblyomma cajennense Fab.), is a common pest of man. PRACTICAL CONTROL OR ERADICATION OF THE SPOTTED-FEVER TICK. In 1909 Dr. Ricketts suggested, in a general way, a plan for the practical eradication of spotted fever from the Bitter Root Valley by a campaign against the ticks. Tt became evident to Dr. Ricketts as the result of his work on spotted fever that the only method of controlling the disease was by destroying the natural agency of transmission. The work of the Bureau of Entomology in cooperation with the Montana Agricultural College and the Biological Survey in obtaining exact information about the life history and hosts of the tick has served to elaborate upon the suggestions made by Dr. Ricketts and to make it possible to lay down definite plans that should he followed. It has been pointed cut in this bulletin that the plan of eradica- tion, which is dependent upon a knowledge of the tick, is entirely feasible and economical. The question now is whether the loss of 25 or more human lives per year in the Bitter Reot Valley, the onus placed upon the development of the valley by the presence of spotted fever, and the danger of the spread of the virulent strain of spotted fever to other regions are not of sufficient importance to justify the small cost that the work will entail. A considerable por- tion of this cost would be offset by the improved condition of the live stock which would result from the destruction of the ticks as well as of certain other parasites. CONDITIONS FAVORING CONTROL. Tt will be understood from the discussion of the life history of the spotted-fever tick that several facts will assist greatly in an attack against it. Among these are the following: (1) The vast majority of fever ticks which develop to the adult stage in the Bitter Root Valley do so upon horses and cattle, although small numbers develop upon sheep and a very few upon dogs. The only other domestic animal of any importance in the Bitter Root Vailey is the hog. Although no fever ticks have ever been found upon hogs in the valley the adult form was taken in considerable numbers on that host on one occasion in Wyoming. It is therefore evident that under some conditions the hog is to be looked upon as an agency for the breeding of the ticks. The danger on this score, however, is exceedingly remote on account of the methed of manage- ment of hogs in the valley. In the first place the number of these animals is not large. In the second place they are not allowed to roam at large but are confined to pens or small inclosures where the chances of their picking up fever ticks are very small. If hogs were © PRACTICAL CONTROL OR ERADICATION. 83 allowed to roam into the brushy land on the edges of the valley they might assume importance, but as the present plan of keeping them confined to areas where, for all practical purposes, ticks do not occur will undoubtedly be continued in the future, it is considered safe to ignore them in a plan of practical eradication. (2) Aside from the domestic animals the wild species which have been found to carry the tick must be considered. These wild mam- mals can be divided for the purposes of this discussion into two groups, namely, those small forms which frequent the floor of the valley and extend in some cases to considerable elevations in the mountains, and the larger forms, like the bear, deer, elk, and moun- tain goat, which are more or less confined to the mountainous walls of the valley, but nevertheless sometimes visit the fields below. Regarding the small wild mammals found throughout the valley. it was ascertained by examination of very large numbers of speci- mens that they seldom or never serve as hosts for the adult ticks. The immature forms of the fever tick are frequently to be found upon these mammals, but the development of the adults is practically restricted to the larger domestic animals. Regarding the larger wild mammals it may be said that their numbers are rapidly decreasing. Some of them are practically extinct. The mountain goat, which appears more or less frequently to carry the adult fever tick, never invades the valley proper. In the winter it is to be found upon the lower rocks of the mountain walls, but it moves back to higher elevations as the snow melts. There- fore mountain goats tend rather to remove ticks from the valley than to plant them there. Among the other possible hosts, the two species of deer are rapidly becoming scarce. Moreover, in our in- vestigations no fever ticks have been found attached to deer. The bear, among the wild mammals, is probably the most likely to serve as a host for the fever tick. It can not be considered that this mam- mal is abundant enough, however, to have any important bearing on the situation. The same is true of the coyote. In fact the number of ticks that could possibly be reared upon all the larger wild hosts would not be sufficient to cause any considerable infestation of the valley. These mammals can not be ignored altogether, but it is safe to con- sider them as comparatively unimportant. They might be of con- siderable importance if the project were to exterminate the fever in the valley and surrounding regions absolutely. But the plan here proposed is to reduce the cases of spotted fever to a practically neg- ligible number in the valley. This is feasible and can be accom- plished at small cost, while total efadication of the fever ticks in the mountains is not necessary to relieve the situation. Since it has been pointed out that the larger domestic animals— horses, cattle, sheep, and dogs—are necessary hosts for the propaga- 34 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. tion of the fever tick, the problem of control becomes very greatly simplified. The immature stages may be allowed to develop on the small mammals in the valley so long as the adult stage may be de- stroyed upon the domestic animals which are necessary for its development. Of course the reduction of the number of rodents in the valley, especially the Columbian ground squirrel, is advisable. These ani- mals are more or less serious agricultural pests. They destroy a considerable amount of produce, and the inhabitants of the valley are in the habit of waging warfare against them. Undoubtedly the damage done is abundantly sufficient to warrant this work. The reduction of the rodents should be encouraged both on general eco- nomic principles and because they carry the immature stages of the spotted-fever tick. This lne of work may well supplement the main work which must be dene with the larger domestic animals, and will undoubtedly hasten the removal of the fever tick from the valley. In one respect work against the rodents is of more than incidental value. It was found by Dr. Ricketts that five of these animals, namely, the gopher, rock squirrel, woodchuck, chipmunk, and moun- tain rat, are susceptible to spotted fever, and may serve as the original source of the disease in nature, or, at any rate, furnish a reservoir from which is derived the infection of human beings by the agency of ticks. The main point, however, is to destroy the tick which is necessary for the propagation of the disease, and this can be done by directing the principal efforts against the ticks on the larger animals which are under the control of man. There are several facts, in addition to the practical restriction of the adult fever tick to the larger domestic animals, which will serve to render a campaign of eradication feasible. One-of these is that the adult ticks are to be found on domestic animals or elsewhere dur- ing only a part of the year. Efforts toward eradication need not begin before March 1 and there would be no necessity for their con- tinuance far beyond June 15. This is the season when the work can be done most easily and with smallest risk to the stock. A line of attack extending throughout the year is entirely unnecessary. An- other favorable factor is the small number of live stock that would have to be treated. This is shown by the table below: TaBLE VII.—Numober cf live stock in Bitter Root Valicy. (U.S. Census, 1900.) Ravalli | Missoula County. | County. Bontoattle....... 0... .. eee eins eee oe ae ea AR 22,461} 13, 684 15 10) 2c ee I EM ome me EC sony ie Pir AEE SiGe ee PG ie et RIE el ee ioe ox 6, 713 | 4,125 Apt shah BRAS 2 ee Be aaere oe: eee. ee wR Wane Md i tloe DER eo ees a eh ae 18 | 36 Pe ions ei tunn chien Pane GiB tte dee SUM Rain Ni Gatien EE cae ae ae een 58,212; 4,942 PRACTICAL CONTROL OR ERADICATION. 35 Moreover, in the Bitter Root Valley eradication would not suffer the drawbacks connected with the ownership of large bodies of land by single persons which have attended similar work that has been undertaken in other parts of the country. The total number of farms in Ravalli County, as given in the census of 1900, was 891; their average size 199.4 acres. In Missoula County the same authority gives 615 farms of an average size of 241.6 acres. An additional advantage will be found in the large proportion of farms in the county which are operated by their owners. Very little difficulty on account of nonresident ownership is to be expected. In Ravalli County 77 per cent of the farms are operated by the owners, and in Missoula County 89. Aside from the specific factors which would operate to facilitate eradication of the spotted fever tick, others of a general nature may be mentioned, namely, the small size of the valley and its practical inclosure by high mountains, and the public interest in eradication which has already arisen. The Bitter Root Valley les between high ranges of mountains over which there is practically no travel. The upper end of the valley is also closed by high mountains over which a very inconsiderable amount of traffic takes place. The lower end is narrowed almost toa gorge. Practically all the traffic into or out of the valley goes through this narrow opening at the northern end. The lay of the land gives an isolated region into which infection from the outside would be very unlikely io take place. For all practical purposes the guarding of the lower end for a portion of the year would be sufficient to prevent reinfection in case eradication is undertaken. The soil of the Bitter Root Valley has been found to be exceedingly fertile and especially adapted to certain profitable crops. It is recognized by all intelligent residents that the principal obstacle to the rapid development which has already begun is the occurrence of spotted fever. There is consequently a firmly em- bedded popular opinion that the destiny of the valley demands the eradication of the fever tick. We may summarize the more important facts and conditions which would facilitate eradication of the fever tick as follows: (1) Practical restriction of the adult stage of the tick to the larger domestic animals. (2) The short season in the spring over which it would be neces- sary to carry on the principal work of eradication. (3) The small number of animals that would have to be treated. (4) The small size of the farms. (5) The preponderance of resident farm owners. — , (6) The isolation of the valley and the existence of effective ' natural barriers against reinfestation. (7) A commendable public opinion in favor of removing an im- portant obstacle to development. 36 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. IMPORTANCE OF CONTROL THROUGHOUT THE BITTER ROOT VALLEY. For several reasons it is necessary to carry on this plan of eradica- tion on both sides of the valley. It is known that the fever is very much less prevalent on the east than on the west side. This situation, however, is undoubtedly in part due to the heavier population on the west side and the greatersnumber of live stock. There is every reason to believe that the settlement of the east side, with the in- evitable increase in the number of live stock and, consequently, of opportunities for the ticks to breed to maturity, would result in an increased number of cases of spotted fever. That this is not a re- mote danger is shown by the fact that the development of the east side has already begun and will undoubtedly continue with rapidity. We do not wish to be understood as believing that the comparatively unsettled condition of the east side is the only reason for the scarcity of ticks. There are undoubtedly others. Among these is the greater abundance of rodent hosts for the immature stages of the tick on the west side. This is due primarily to the larger amount of protection in the brush or “slashings,” although the settlement of the land and the planting oz crops may have tended, by furnishing food, toward the multiplication of the rodents. Soil conditions may also have something to do with the difference. The main point, however, is that the comparative immunity of the east side is not likely to continue. Destroying the ticks on both sides would cost but little more than on one. It would prevent the rein- festation of the west side. If it were not done, it would be necessary to establish and to maintain a quarantine against live stock on the east side. From every point of view it is wise to conduct a thorough work and clear both sides of the valley at the same time. METHODS OF DESTROYING TICKS. The two methods of eradicating ticks which will be found to be adapted to the conditions of the Bitter Root Valley are (1) the dipping of live stock in vats provided for the purpose, and (2) the hand treatment of such animals as can not conveniently be dipped. In the case of the tick (Margaropus annulatus Say) which trans- mits splenetic fever of cattle, a third method has been found to be of great importance. This is the elimination of the ticks from pastures by “starving” them. This is accomplished by keeping the cattle out. During the warm portions of the year, at least, only a few months time without hosts will result in the death of the cattle ticks. Im- portant differences between the life history of the splenetic-fever tick and that of the spotted-fever tick make that plan entirely imprac- ticable in the case of the latter species. The problem of the splenetic- fever tick is not complicated by the existence of different hosts for the immature and the adult stages. That tick is absolutely depend- METHODS OF DESTROYING TICKS, 37 ent upon cattle and remains on its host until mature. The spotted fever tick, however, drops to the ground twice for the purpose of molting and develops through the immature stages upon certain rodents and other animals. In the opinion of the Biological Survey the extermination of these rodents within reasonable time appears to be impracticable because of the necessary expense. The problem is even further complicated by the remarkable ability of the fever ticks to live for long periods without hosts. As shown in the dis- cussion of the longevity of the stages of the spotted fever tick, a period of three years, in which horses and cattle were kept out of the pastures, would be required before eradication could be brought about. This long period renders the so-called starvation plan entirely impracticable. ; DIPPING. Undoubtedly the so-called arsenical dip is the one best adapted for use in the Bitter Root Valley. In fact this dip has practically displaced all others for the destruction of ticks in various parts of the world. Crude oils have been used to a considerable extent in some cases. They are more expensive than the arsenical dip and dangerous to cattle under some conditions. Serious losses have fol- lowed the use of heavy oils in dry regions or where it has been neces- sary to drive the cattle any considerable distance after dipping. Another advantage that the arsenical dip will be found to have over crude oil for the work in the Bitter Root Valley is that it will not act as a repellent. When cattle are oiled a portion of the oil remains in the hair and upon the skin for several days. This will prevent ticks from attaching. In the case of the arsenical dip, how- ever, there is very little repellent effect. As the object of the work is to kill the ticks rather than to keep them from the animals, the more that can be caused to attach the better. The formula for the arsenical dip is as follows: Nodiunmecanvponate (sale soda") 25 2= eS eee pounds._ 24 ATSCHIGE OMG CWhELe drsenic) 22 so Be COLEES SS DGS fea 22 i A eR Se lee Ee ee gallons_. 2 ue oue OL nee ae ee Be SS Es a ee ee does =27500 The preparation of the arsenical dip is described in Farmers’ Bul- letin No. 378, Methods of Exterminating the Texas-fever Tick, pre- pared by the Bureau of Animal Industry of this department, as follows: In preparing the dip, a large caldron or galvanized tank is required for heat- ing the water in which to dissolve the chemicals. Thirty or forty gallons of water should be placed in the caldron or tank and brought to a boil. The sodium carbonate is then added and dissolved by stirring. When this is accom- plished, the arsenic is added and dissolved in a similar manner. ‘The fire is then drawn and the pine tar added slowly in a thin stream and thoroughly mixed with the dip by constant stirring. This strong stock solution is diluted to make 500 gallons before using. THE ROCKY MOUNTAIN SPOTTED FEVER TICK. 38 C8 ~ & UNM Stomey “PIABIH Woy) yea Surddip oj049u09 10 poom aAOZ SSUIMVIG—'s “DIT PF MES Oe He — Pepe k vas Taal! Sark) Goer! Ae he. See am ee YDS hi: SH YAW GW. eS On She See a ae cate See }- : 1 iS RSS SS eee a ee ee 1-4 ‘ 1 H i} + es mA F h ' 1 iss ree 4 = rt HH ; 1 oO. i ‘| T Bicrs ov ae | ONY. ak ‘ hi INN yy wis kowd Bay e a HL Min MS Vs WEDS : RS ae Tea ee . ee Pe ee mi SPEED 7 my a ce HH is Sai 149 90 One ~ ty n> 95100 ie 2 7 1 ca Ti = a ist ss TT am Hi ; : Z ~B%S SVE “te = VOM LES/ Clw27) ‘CFAvaTD YOUTY 9-2¢x0:27 NIG INidAd/at wu <— Wie HILIE OL WOOT LvA 40 NYTd = OMIAOOTY 9pz,asf warn OINIT SCALE 2. "POOL Weed Ni] TY WOLLOF ae AOINIT BELNID__ Uae it 11 On reall | + hi mitt Meit . H tt : 4 ee EE = tt tf on alla Wasi 72 oe 1 ' "ORNTAWD CENIOL “ANWTD Om, TC NLIM CINIT CLEOS Ym fe H 0b sot oe = He ek a Qn | Ca oe eff Se The only precautions necessary are to see that live stock are not allowed to drink it and to avoid heating the animals either before or after dipping. The dip can be used repeatedly until it becomes Nid WNiad/ag A reasonable estimate of the cost of preparing this dip in the valley is $0.0031 per gallon, or $6.20 for an amount sufficient to fill a vat of 2,000 gallons capac befouled by foreign matter. ty. i METHODS OF DESTROYING TICKS, 39 CONSTRUCTION OF VATS. The specifications fer such vats as will be found best adapted to use in Montana are taken from Farmers’ Bulletin No. 378, already referred to, as follows: SPECIFICATIONS AND MATERIALS FOR A DIPPING VAT, A vat constructed according to the accompanying plans will hold 2,088 gallons when filled to a depth of 5 feet. Haecavation—Excavate for the vat, as shown by the drawings [fig. 3], to the proper depth. Level the bottom of the pit for the sills. After the vat is com- pleted fill in around it, using the surplus natural grade, and slope the surface away from the vat. Dig the holes required for all posts, ete. Carpenter work.—The drawings show the vat constructed according to two methods. One method is to make the sides of 4 by 4 inch posts spaced about 3 feet apart and lined with 2 by 8 inch dressed, sized, and bevel-edged plank, using 20-penny spikes to fasten them to the posts and braces. All the joints are to be calked with oakum, well driven in with a ecalking iron, and pitched. The floor of the vat and the inclines are to be made of 2-inch plank, with joints calked;: the exit incline to have 2 by 4 inch cleats spiked to the plank flooring. The slide should have an angle of about 25° and should be coyered with No. 16 galvanized iron. The other method is to build the sides of the vat of 2 by 4 inch posts and 2 by 4 inch braces spaced about 16 inches on centers. The 2 by 4 inch posts and braces are to be lined with ~ by 8 inch tongued-and-grooved flooring, blind nailed at every bearing with 10-penny nails. All the joints are to be laid in white-lead paste and the boards firmly driven up. Lumber.—The lumber used in the construction of the vat must be thoroughly dried and seasoned stock, free from large and loose knots, straight grained, and free from sap. Gutters.—The gutters for the dripping pens should be made of sound stock, the bottom plank housed into the sides and ends, and the ends housed into the sides. All the joints are to be laid in white-lead paste and thoroughly nailed. Gutters are to have a 3-inch fall in 11 feet. Bill of materials for vat and draining pens, Vat: Sills, 8 pieces 4 by 4 inches by 10 feet long. Posts— 1 piece 4 by 4 inches by 16 feet long. 1 piece 4 by 4 inches by 14 feet long. 6 pieces 4 by 4 inches by 12 feet long. 5 pieces 4 by 4 inches by 10 feet long. Braces— 1 piece 4 by 4 inches by 16 feet long. 6 pieces 4 by 4 inches by 12 feet long. 1 piece 4 by 4 inches by 10 feet long. 1 piece 4 by 4 inches by 6 feet long. Guards— 2 pieces 2 by 8 inches by 18 feet long. 1 piece 2 by 8 inches by 16 feet long. 2 pieces 2 by 8 inches by 12 feet long. 1 piece 2 by 8 inches by 10 feet long. 40 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. Vat—Continued. Sides— 18 pieces 2 by 8 inches by 20 feet long. 25 pieces 2 by 8 inches by 18 feet long. 2 pieces 2 by 8 inches by 16 feet long. 2 pieces 2 by 6 inches by 18 feet long. Dressed one side and two edges. Edges beveled for calking. Floor— 3 pieces 2 by 10 inches by 20 feet long. 2 pieces 2 by 10 inches by 16 feet long. 1 piece 2 by 10 inches by 14 feet long. 1 piece 2 by 10 inches by 7 feet long. 1 piece 2 by 12 inches by 12 feet long. Dressed one side and two edges. Edges beveled for calking. Cleats, 4 pieces 2 by 4 inches by 12 feet long. Lumber for draining pens: Mud sills, 10 pieces 4 by 12 inches by 2 feet long (cedar or cypress). Sleepers, 4 pieces 6 by 6 inches by 12 feet long. Joists, 18 pieces 2 by 12 inches by 12 feet long. Floor, 560 feet b. m. tongue-and-gréove flooring ~ by 8 inches, 12-foot pieces. Cleats, 265 linear feet 1 by 3 inches. Gutters— Sides, 4 pieces 2 by 12 inches by 11 feet long (dressed). sottom and ends, 2 pieces 2 by 12 inches by 12 feet (dressed). Bottom housed into side and ends. Ends housed into sides. All joints calked and white leaded or pitched. Posts— 11 pieces 4 by 4 inches by 7 feet long. 2 pieces 4 by 4 inches by 8 feet long. 2 pieces 4 by 4 inches by 9 feet long. Rails— 2 pieces 2 by 8 inches by 18 feet long. 5 pieces 2 by 8 inches by 16 feet long. 18 pieces 2 by 8 inches by 12 feet long. Braces, 2 pieces 2 by 4 inches by 10 feet long. Gates— 7 pieces 1 by 6 inches by 12 feet long. 6 pieces 1 by 6 inches by 10 feet long. Hardware for vat and draining pens: 4 pairs 12-inch heavy T hinges and screws. 4 wrought-iron hooks and staples. 1 pair wrought-iron hook hinges, 12-inch, wood screw hooks, and screws. 50 pounds 20-penny wire nails. 15 pounds 10-penny wire nails. 12 square feet No. 16 galvanized iron. The vat described is of the proper depth for cattle and horses. For sheep a platform should be provided which will rest on legs long enough to bring this platform 4 feet below the surface of the dip. This can be easily made so that it can be removed or replaced in a METHODS OF DESTROYING TICKS. 41 few minutes to allow, if necessary, for the alternate dipping of cattle and sheep. In selecting a site for the construction of the vat the desirability of having the ground slope away from it on one side should be kept in mind. This allows for the draining of the vat through a pipe inserted at its bottom. This drain should lead to a basin, prefer- ably on waste land. Care should be exercised to prevent animals from drinking from the pool into which the old dip is drained and ulso to prevent the dip from being washed into streams used for domestic purposes. In order to prevent the dip from becoming diluted by rains and to check evaporation, a roof of boards or canvas over the vat is desirable. HANDWORK* IN THE DESTRUCTION OF THE SPOTTED-FEVER TICK. For the most part the use of dipping vats will furnish all facili- ties necessary for the eradication of the ticks. However, in certain cases, as, for instance, in the narrow valleys running some distance into the mountains, the expense of constructing dipping vats for the small number of cattle present would be prohibitive. Instead of driving these cattle considerable distances to dipping vats, it will be found sufficient to treat them thoroughly by hand methods. The procedure is simply to apply the arsenical dipping mixture liberally by means of rags, mops, or brushes, or by means of spray pumps. It may be found advisable in some cases to use oil instead of the dip, although the main reliance should be placed upon the use of the dip. Oil from Wyoming, which will be found perfectly adapted to this use, can be obtained in the Bitter Root Valley, when pur- chased in large quantities, at a cost of about $1.25 per barrel. DEFINITE RECOMMENDATIONS FOR CONTROL OR ERADICATION OF THE SPOTTED-FEVER TICK IN THE BITTER ROOT VALLEY. The following are the steps that should be followed for the control or eradication of the spotted-fever tick in the Bitter Root Valley: (1) A campaign of education whereby all the residents of the valley will be made thoroughly familiar with the feasibility of the plan of eradication and with what it will mean in the development of the valley. (2) The obtaining of legislation to make it possible to dip or oil all live stock in the Bitter Root Valley. In general, public opinion would be sufficient to bring about the treatment of a large majority of the animals. In a few cases objections would undoubtedly be raised by farmers. Without the treatment of all live stock, the plan would necessarily fail. For this reason it is absolutely essential to 42 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. provide such legislation as will make it possible to enforce the treat- ment of all the animals. (3) The obtaining of an accurate census of the horses, cattle, sheep, mules, and dogs in the valley. (4) The construction of 10 or more dipping vats. (5) The providing of materials to be used in the dipping mixture. (6) The organization of a corps of workers to carry on the operations. (7) The systematic dipping of the horses, cattle, sheep, and dogs of the valley on a definite schedule. The time of beginning and of discontinuing this work will depend somewhat upon the seasons, but should be about as indicated below. Weekly dippings are necessary, because, as pointed out in the discussion of the life history of the tick, adults may attach to domestic animals, engorge, and drop to the ground in a minimum of eight days: March 10. March 17. March 24. March 31. (Vat refilled on this date.) April 7. April 14. April 21. (Vat refilled on this date.) April 28. May 5. May 12. May 19. (Vat refilled on this date.) May 26. June 2. June 9. (8) The treatment by hand of the animals in localities remote from vats should be undertaken on this same schedule. One season’s work would certainly result in a very large reduc- tion in the number of fever ticks present in the valley. The second season’s operations would bring about still further reduction in num- bers, if not practical eradication. Nevertheless, a third season’s work is required to make certain of the results. ESTIMATED EXPENSES OF PRACTICAL ERADICATION OF SPOTTED-FEVER TICK IN THE BITTER ROOT VALLEY, MONT., NOT INCLUDING THE COST OF EXPERT SUPERVISION AND NECESSARY INVESTIGATION. The approximate cost of the work for the three seasons is indi- cated in the statement given herewith, which does not, however, include the cost of such expert supervision and additional investiga- tion as are required. METHODS OF DESTROYING TICKS. 43 First year: DO vats; costing $200neaqh 44: eee ee $2, 000 Each vat to have a capacity of 2,000 gallons. Cost of filling vats four times during season, at $0.0031 per gallon.*t_ 248 Salary of one superintendent, 22 months. _-___-_______________ 1, 800 Salaries of 10 assistants for 5 months, at $80 each ___________ 4, 000 The period to be covered by these men extends from Feb. 15 to July 15. [ater a Kn il ho a Re oe Ree eS Pe Re eee POE Ros 1, 000 TROVE 9-4 CHS) eipeh 72k ea pa een a Ep ame care See OO SA PAN ee = 9, O48 Second year: LES 2 UES HUES he Weg 3S apa el ea Ap a Se le Oe IS ply he ad 200 Cost of-fillmg vats'four ‘times during season______________-_________ 248 SHHaiyOL (One ssi perin tantent ais tees Oe yey Peay th egg 1, 800 Sadaries| [o6]4'O fa ssishants 2-45 - See eg Sed ee a 4, 000 Do S318 PE8 a2 AS eu I cna aL a le OE ce ee = ae ee oe 1, 000 BIACp et re SECO Cen V eu eters Sen Ree cee a ee ee = 2 ee 7, 248 Third year: PIMESTOELM TES PEO ORNS ee ee FES Peale ed yk ee St yal ee Ney 300 COS Ola tat? Weck UT Tmt LISS es a 248 Salve OMe SS penen tENGON ts. 2 se a ate ee Ee 1, 800 SULT TRE Sb hd KORE SFG UST 2S oe I SE ads ee es eee 4, 000 SUUVETKo ese UR Sie Ss eo EEL ee oe SL i ed ee a 1, 000 ANG EM War TROD | ete lee es Coe eat ow Sa oh oy eee ue es ree Pee eee Sane es 2 eer 7, 348 (Grate naVe lye ss) Psi Ie ye RT eRe exc erie Oa eo. Eo en ae ce eer, ere 23, 692 It may be found that more than 10 vats will be required. In that case the output for materials would be increased somewhat. After three seasons’ operations a very small annual expenditure will be necessary to avoid reinfestation of the valley by the incom- ing of cattle from other places. This could be easily accomplished by employing an inspector at a salary of, say, $100 per month for six months’ service each year. SUPPLEMENTARY MEANS OF CONTROL. The main reliance in work of controlling the spotted-fever tick must be placed upon the dipping and hand treatment of domestic animals. However, there are certain supplementary means of con- trol which should be practiced. These are (1) the reduction in the number of rodents in the valley and (2) the clearing of the brush land along the edges of the valley. As has been explained in this bulletin, the destruction of the ro- dents is not a vital part of the plan of eradication we propose. 1The cost of dip per gallon is computed as follows: Arsenate trioxide, 54 cents per pound ; sodium carbonate, 2 cents per pound; tar, 334 cents per gallon. ‘ 44 THE ROCKY MOUNTAIN SPOTTED FEVER TICK. Nevertheless, if the number of these animals can be reduced, it wili have an important effect in lessening the number of ticks present. In addition to this reason for control, the rodents are pests of con- siderable importance. Their extermination from the valley, if pos- sible, would amply repay the residents in the preventing of losses to their crops. The conditions existing in the brushy land or “slashings” along the edge of the valley are especially favorable to the tick. Not only is shade and protection furnished, but the presence of the timber furnishes the rodent hosts favorable opportunities for multiplication. In this way the presence of the brush has an important bearing upon the abundance of ticks. If the land should be cleared, the ticks would be considerably affected. Clearing the lands will, of course, increase their value and make possible their planting in orchards or other crops without loss of time when the fever tick shall have come under subjection. For a full list of the mammals found in and around the valley and for methods for their extermination the reader is referred to Circu- lar 82 of the Biological Survey of this department. It is not considered necessary to have these supplementary means of control supported by funds raised for the main operations. The work of destroying rodents and of clearing the brush lands should be conducted by residents on their own initiative. The matter should be sufficiently explained and the residents should by every means possible be encouraged to undertake the work. NECESSITY FOR EXPERT SUPERVISION. In the work of controlling the spotted-fever tick in the Bitter Root Valley it is absolutely essential that expert entomological supervision be provided. Since the whole campaign depends upon a knowledge of the habits and life history of ticks it must be evident that the work must be in the hands of persons who are thoroughly familiar with the subject. Among the many reasons why this expert supervision is necessary are— (1) The proper time to begin and to discontinue the dipping or oiling must be determined. This will depend upon the seasons and the time when the tick begins to develop in the spring. Unless men are at hand to determine when to begin and when to end, much un- necessary work might be done or, what is worse, many ticks might escape. (2) It is necessary to be certain that the dipping solution is kept up to a strength sufficient to kill and to see that the dipping is prop- erly done. The test of the strength of the solution should be con- ducted by experiments the results of which could be interpreted safely only by experts. BIBLIOGRAPHY. 45 (3) The campaign of education which should be conducted in con- nection with the other work can only be carried on effectively by persons who by training and experience know thoroughly the points upon which the system is based. The best work can only be done by those who have had experience in similar problems and who are familiar with data sufficient to refute such fallacious arguments as may be adduced from time to time. (4) It is possible that means of control additional to those enu- merated in this bulletin may be discovered. The chance of such discoveries and the consequent hastening of the work will be in- creased if persons trained in entomological work are in charge. BIBLIOGRAPHY OF THE MORE IMPORTANT WRITINGS ON THE SPOTTED-FEVER TICK. 1902. ANDERSON, J. F. : Spotted fever (tick fever) of the Rocky Mountains.