NOTES ON BIOLOGY OF SOME MUSCOID FLIES. JOHNSTON. 95 



egg deposition by a fly and oviposition by the progeny of such 

 fly (p. 16). Howard and Hutchison (1915, 1917) showed that 

 in Washington D.C. such wovild be possible in from 11 to 14 

 days during midsummer. We do not know the minimum 

 preoviposition period in Brisbane, but, as our chmatic con- 

 ditions during summer are somewhat similar to those in 

 which Hutchison obtained his minimum results, it is likely 

 that in the coastal districts of Queensland during midsummer 

 (say January to March) a period of from 9 to 11 days may 

 represent the minimum period between egg deposition by a fly 

 and by its progen}'. 



We have no information regarding the length of time 

 houseflies can live in captivity in Austraha, but Austen (1920) 

 mentioned 7 to 16 weeks in England ; while Howard and 

 Hutchison (1915) recorded periods of 30 days during winter 

 (Xew Orleans), 35 to 40 days at temperatures of 65-75° F. 

 (Virginia), one of 70 days at a temperature ranging from 32° 

 to 50° F. (Virginia), and (1917) one of 91 days (44-57° F.). 

 Hutchison (1916) recorded a longe^^ty var;v'ing from 1 to 54 

 days (average of 3,000 records being 19+ days) during summer 

 and autumn (U.S.A.). On account of the much Avarmer 

 chmate of Australia, such long life-periods are unlikeh^ to 

 occur here normally. 



Bishopp, Dove, and Parman (1915), working at Dallas and 

 Uvalde, Texas, found that eggs hatched in less than 24 hours 

 even in winter ; the larval stages required from 3|^ days to about 

 3 weeks, usually 4 to 7 days during warm weather ; pupal stage 

 3 to 26 days, ranging to more than 2 months during winter ; 

 time from egg to emergence 8 to 11 days (midsummer) increasing 

 to 25 to 51 (midwinter) ; and in one case the combined larval 

 and pupal stages occupied 6 months (Xovember to May). 

 Copulation was observed to occur from 1 to 16 days after 

 emergence. Oviposition took place in from 4 to 20 daj's after 

 emergence — usually 4 to 9 days in summer and 10 or more in 

 autumn. Longevity in captivity was found to be from 2 to 

 53 days — generally 2 to 4 weeks during summer when food 

 was sufficient. 



Musca vetustissima Walker. 



This is the common, small, dark, bush fly of Australia 



and has been referred to in literature under a variety of names. 



Coquillet determined it for Froggatt (1905) as Musca corvina 



Fabr. (a European fly now known as M. autumnalis Geer.), 



