Vol. XXvi] ENTOMOLOGICAL NEWS. 263 



How Does the House-fly Pass the Winter? (Dipt.). 



By HENRY SKINNER. 



In Entomological News, xxiv, 303, 1913, I published an 

 article with the above title and stated that I believed that in 

 the vicinity of Philadelphia Musca domestica lived through the 

 winter in the pupal stage. This article led Dr. S. Moncton 

 Copeman and Mr. E. E. Austen to investigate the same sub- 

 ject in England. They published the results of their investi- 

 gations in "Reports to the Local Government Board on Pub- 

 lic Health and Medical Subjects, New Series, No. 102, 1914, 

 London, England." They sent out appeals, for specimens, to 

 be published in certain journals. The notice was printed in 

 "Country Life," "The Entomologist" and "The Entomologists' 

 Monthly Magazine." From January 19 to April 27 they received 

 fifty-eight consignments of flies, representing fifteen species. 

 They gave an extensive tabulated report of the specimens re- 

 ceived which is very interesting and instructive. Their sum- 

 mary and conclusion is as follows : "It will be seen from the 

 appendix that the results obtained afford no support to the be- 

 lief that house-flies hibernate in this country [England] in the 

 adult state. The few specimens of Musca domestica sent in 

 were all taken in an active condition ; some of the other flies, 

 however, such as the extremely common Pollenia rndis F., 

 were often found partially dormant, and it is difficult to resist 

 the conclusion that did the house-fly really hibernate in the 

 adult state some evidence of the fact must have been ob- 

 tained. The idea suggests itself that the relative lateness of 

 the season at which house-flies annually become abundant may 

 be due to the smallness of the number of individuals that, in 

 an active condition, survive the winter in houses and other 

 buildings, although it must be admitted that as yet (there is] 

 nothing in the shape of proof that female house-flies found 

 alive at the end of winter actually survive until oviposition 

 takes place." They say in conclusion "it would appear that 

 the customary explanation of the perpetuation of the house- 

 fly from year to year has now been fairly tested, and that the 

 evidence obtained fails to support it." 



