APPENDIX B 184 



the substances in which they are able to breed, and to make 

 this account of the bionomics of Musca domestica as complete 

 as possible I am giving a brief account of them here. 



In the collection of Diptera in the Division of Entomology 

 of the Department of Agriculture of Canada, I found 

 specimens of M. domestica which had been reared in ger- 

 minating wheat. The parent fly had no doubt chosen such 

 material as an admirable nidus for her progeny, as 

 germinating wheat, on account v of the fermentation taking 

 place in the same, forms an excellent substance for the 

 development of the Iarva3. 



Allied to this observation are some experiments by Nash 

 (1909) in which he reared flies in fermenting bread, and 

 his methods were followed by Jepson in the experiments 

 already recorded. Nash also mentions (I.e.) that he has 

 succeeded in rearing them on pear, potato, banana skins, 

 boiled rice and old paper, but he experienced the same 

 failure as I did in attempting to breed them in cheese. He 

 records an interesting observation of Austen's which the 

 latter made in 1908. Austen found the larvae of M. domestica 

 in rubber which was suspended in a drying room at a 

 temperature of 100 F. They were apparently full grown 

 and the circumstances indicated that they could not have 

 been more than three days in developing from the egg stage, 

 which indicated a rapid growth at this exceedingly high 

 temperature. 



The foregoing observations taken in conjunction with those 

 of my own and other investigators given in the second part 

 of this monograph emphasise the fact that M. domestica is 

 able to breed in practically any decaying animal or vegetable 

 substance or excrement, especially if it is in a state of fer~ 

 mentation and if there is a sufficient amount of moisture 

 and a suitable temperature, the last two conditions being 

 concomitant with fermentation. 



