Gregson, J. D.

English

Journal of the Entomological Society of British Columbia

ENTOMOLOGICAL SOc. OF BRITISH C OLUMBIA. PROC. ( 1949). V OL. 4 6. MAY 15 , 1950 3 larvae taken by the writer at Nicola , August 25 , 1932, in a pack rat , was allowed to pupate in earth in the out-of-doors insectary at Kamioops, and emerged in mid-August . 1933. Conclusions: Some of the foregoing observations suggest the following de-ductions regarding the habits of C. tene-brosa. It is usually assumed that the female fl y lays her eggs on the hair of the host animal. The extreme viability of the egg and the longevity and mo tility of the unfed maggot are specializations which would seem unnecessary were the above assumption true. It seems, there-fore, more probable to suppose that the eggs are laid among the rocks, logs, nests, or burrows frequented by pack rats , chipmunks, and ground squirrels, the commonest hosts. In support of this , H . B. Leech has told the writer that he captured in 1929 a femal e of this species in the mouth of a burrow of a ground squirrel or groundhog at Vernon , B. C The growth in the host is amazingl y rapid , little over a month being required for larval development. The pupal stage, on the other hand, is ext raordi-narily long and may last a year, but in order for the life-cycle to be completed in a year , the average duration of this stage cannot be more than 10 or 11 months. A two-year cycle, however. does not seem impossible when the via-bility of the eggs, even in cold weather. is considered . It may have been because of room temperatures , about 70 a F. , that so many eggs hatched within three months, although the humidity of the room, about 20 per cent, may have been an adverse factor. According to our records of grubs taken from rodents, flies of this group thrive best in localities such as Nicola , Salmon Arm, and Ver-non , which have a relatively heavy snowfall. They are rare at Kamloops. The mortality of rats in the foregoing experiments suggests that this fly may cause the death of small mammals in nature in certain localities, although a general infection may be induced by the grubs less easily in mountain rats than in those used in the laboratory. If they do constitute a factor in reducing popu-lations of wild rodents , then they be-come a factor in the control of wood ticks , and deserve further study. Acknowledgments. - The writer is indebted to E. P . Venables, Vernon , B. C, for the material for these experi-ments. Thanks are also due to H. B. Leech, California Academy of Science, San Francisco, for his record, and to George J . Spencer , University of British Columbia, for reading this manuscript. ADDITIONAL NOTES ON THE LIFE-H ISTORY OF CUTEREBRA TENEBROSA COQUILLETI J. D. GREGSON Livestock Insec t Laboratory, Kamloops , B. C. At the 1935 meetings of the E ntomo-logical Society of British Columbia , T. K. M oiIIiet read a paper entitl ed "Notes on the life-history of Cuterebra tene-brosa Coquillet." In that paper, which is being published concurrently with this one, he reported his observations on some 400 eggs laid by a fly captured on August 23, 1934. Larvae commenced hatching from these eggs on September 27, reaching a peak in November. Some 1 Contribu tion No. 2n:i;;, Dhision of E1ltomology, Science S el'Yi c::e, Department of Agri cult. ure. Ottawa, Canada. of the remainin g unhatched eggs yielded active larvae when mechanically opened in February. Numbers of these larvae were used to infest rats, in which they matured in about a month . Since none of these were foIIowed through their pupal period to emergence of adults , the following notes may prove of value in further studies of this parasite. The material for these subsequent observations was provided by a batch of 850 eggs deposited by a fly on July 26, 1943. The first of these hatched on 4 ENTOMOLOGICAL SOc. OF BRITISH COLUMBIA, PROC. ( 1 9 4 9 ) , VOL. 46 , MAY 15 , 1950 August 20. Further larvae did not ap-pear normally until the following May. By June 15 all remaining eggs had hatched . Larvae kept in the damp cel-lar of the insectary lived for about three weeks after hatching. After the appear-ance of the first larva, it was found that eggs could be readily induced to hatch by pricking open the operculum with a sharp needle, or even by merely dislodg-ing the egg from its attachment. In September, 1943, 43 white rats were each infested with from one to four larvae which had been obtained by me-chanical hatching. Of the 89 cuterebrid larvae planted on these hosts , 23 ma-tured and dropped out after an interval of about five weeks. The mortality of the infested rats was approximately 30 per cent, although it must be admitted that some of these animals were the vic-tims of as many as four grubs at once. Most of the grubs were localized in regions about the head and shoulders . Upon being placed on loose soil the mature grubs burrowed, pupated, and remained quiescent until August I , SOME RECORDS OF PARASITIC DIPTERA FROM WELLINGTON, B. C. BOMBYLII DAE Vifla alternata , Say Aug. 1 0, 1941i. Bred fro m a l:Hge p lw laen id lana , s pecies u nk nown. TACHINIDAE Bombyliops is abrupta ( \Vied.) . . June S. ] 9-1 :) . Bre d fmm la rva of Diacrisia virgini ca (Lepidoptera, Ardii-dOle). 14 .V I. 45. ' l'ake n on woodla nd path. Rileymyia n. s p .. ~ra r. 3, 1 9 4 ~)' Bred from la l'nl of Halisidota argentata ( Arctiidae). Th e adu l t form of H. argentata appears in t he summ er, after a very short pE'r im) aR a pupa. Thus t he pa ra.si te in this caSe does flot foll ow t h e life cy('le of it ~ host, bu t m ust a ttack t he ~ ,art Jy growll larvae in spring . ~f r. A. R . Brook s advises m e th a t the same spf'c ies has been hred from Mal acosoma sp., which passes t he winter in th e egg s tage. Peleteria obsoleta Cn. , Aug. lR . 19 ·1(;. Take n Oil flowers of Anaphalis margaritacea , Aug. 5 , ] 9 47. Bre(i from t he larva of an unknown phalaen id moth on grassy foreshore. Peloteria campestre, Cn., Aug. 18. 1946. Ta ken on Mowers of Anaphalis margaritacea. Bonellimyia tesseflata, Brooks. i'lel't. 26, 1 9 46. Thi s spe<:i m en t aken ill the house during ea rly a ut umn , was proba bly seek ing a pla ce for hibernation. J am indebted t o Mr. Brooks for t he following information on t he tax-onomy of B. tessellata-" Bonellimyia is a segregat e of the old genus Linnaemyia Des. and tessellata is aIle of three species \vllir.h were fOlmerly known as Linna~ myia haemorrhoidis Fall. " Uromacquartia halisidotae (Tn s. ) , t wo speci m ens, June 6. 1 !J 4 fi. Bren from larvae of H. argentata. The ('a te rpiIla r::;l \vere taken the previ ous August while very sm a ll and kept in a cotton sleeve over \,,·int er. In this 1944, when the insects of the earlier infestations commenced to emerge as adults . With a pupal period of nearly II months, the life-cycle of this cutere-brid is just the opposite of those of the cattle warbles, as the periods spent with-in the host as a larva and in the ground as a puparium are approximately re-versed. The fact that up to nearly a year after oviposition the eggs may re-main viable and even hatch with the mechanical aid of a host brushing by suggests that the cycle of the warble fly of this rodent may on occasion last as long as two years. As surmised by Moilliet, it appears probable that this fly does not oviposit on the hairs of its host but deposits its eggs upon debris about the entrance of its burrow. From evidence gained at this laboratory that mice readily eat puparia of cattle warbles , and the fact that gnawed shells of cuterebrid puparia are frequently seen about pack rat nests , it seems likel y that this stage of the fly is particularly vulnerable to this means of natural control. case infel'ltat ion must ta ke place ~oon after the host lan-ae a re h atcl lE~d . t he pa ra~ite following nearly th e sam e li fe cycle. The e m ergeBce dat e is som e\,.·h a t earli e r t ha n i~ ('ommot! fo r t he moths. Lydefla nigrita Tn •. . ,lune 24. 1 H4H. a lso t wo speci· m ens. )[uv 28. ] 94 j . B oth bred from larvae of Arzama obliQua ( Pha1:apn idae). The ca t erpilla rs in · fested \v i t h t hi s parasite di e ill the au t umn withou t pu va t ing. a nd t he maggot!=> It;>.n·e th e body of the host to pupate. Em ergen ce da tes ill s pr ing coincided with t he a ppeara n<'e of t he host a dult:" . Tachinomyia va ria ia CIl . . Avril 2 ·1, 1 9 4 -; . Bred from pupa of Malacosom a pluviale (tent cat erp illar) . Th i ~ speci es a l~o oH'l'-willtrl'S as a p upa. Argentoepal pus significus ( Wlk. ) . April ~ 7 . 1 94 7 . .\11 th e above determinations \\'ere kindly m ade by ~fl'. .1. H. Brooks, Otta\\"a.-·Richal'o Guppy, Wellington. H. c . A WINTER CRANE-FLY, TRICHOCERA ANNULATA, AT VERNON , B.C. ( Dipt eJ'a: Tric hoce ridae )-In Vol ume 44 of t his journal, G. ,J. S pencer lis ted t wo species of Trichocera as occurring in t he province. I n th e late fa U of 1 944 my wife a nn I t ook a series of a t hird s pecies, da ncing in a swa rm a bout four feet above our lawn at Vernon, B. C. Exampl es were sent to C. P. Alexander, who repli ed in a letter dated Feb,"uary 23 . 1 9 45: " Your species is Trichocera annulata Meigen. wh ich has b een known t o m e in North Amer ica on ly from Bergroth's record from Sitka. Alaska. Strange t o say. since receiving your specimens, it has turned up in CalifoTIlia. The s p ecies has been carried by commerce to many parts of th e world . , ." - Hugh B. Leech. Calif. Acad. S cL, S an "~rancisco, Calif. 

Additional notes on the life-history of Cuterebra tenebrosa Coquillet

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Additional notes on the life-history of Cuterebra tenebrosa Coquillet

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Journal of the Entomological Society of British Columbia