NOTES ON BIOLOGY OF SOME MUSCOID PLIES. JOHNSTON. 83 



such as Anestellorhina augur, Pollefiia stygia, and Lucilia 

 sericata, while those of Ophyra nigra would attack all species. 



Patton mentioned that the female lays her eggs amongst 

 those of other Calliphorines ; that the first instar lasts for 

 about 36 hours, as in the case of C. villeneuvii, and the second 

 from 2 to 3 days. 



The biology of the related fly Chrysomyia (or better, 

 CocMiomyia) maceUaria Fabr., well known as the American 

 screw-worm, wlfich deposits its eggs in hving domesticated 

 animals as well as in man, but especially in cattle and sheep, 

 has been worked out by various investigators. Bishopp, 

 Mitchell, and Parman (1917) reported that eggs hatch in less 

 than 4 hours, and when infesting Hving animals the larvae 

 are mature and drop from the Avound in from 4 to 5 days, 

 but when in carcasses they require 6 to 20 days unless the 

 weather be hot and damp. The maggots burrow from 1 to 4 

 inches into the ground before pupating. The pupal stage 

 lasts from 3 to 14 days, when the flies emerge and are soon 

 ready (3 to 18 days) for egg-laying. The whole life-cycle is 

 completed in from 1 to 4 weeks according to temperature and 

 humidity. The adult fly lives only a short time — from 2 to 

 6 weeks. [See also Bishopp, 1915, p. 325-6.) 



Herms (1915, p. 235) reported that the shortest period 

 observed to elapse between the deposition of the egg or maggot 

 to the emergence of the imago Avas 9 days, lengthening to 2: 

 weeks or more under less favourable circumstances. Castellani 

 and Chalmers (1919, p. 848) stated that the eggs hatched in 

 from 1 to 9 hours, the larva matured in from 5 to 7 days, and 

 the pupa in from 9 to 14 days. {See also Hall, 1921, p. 15.) 



Chrysomyia (Microcalliphora) varipes Macquart. 

 Tliis is the smaller hairy maggot-fly, commonly known as 

 Pycnosoma varipes. Probably more than one species has been 

 included in the previous accounts given under this name. 

 Townsendin 1916 made it the type of his genus Microcalliphora. 

 Though common during summer, this fly reaches its maximum 

 development in Brisbane in February, during which month 

 its life-cycle may be very much shortened, at times not more 

 than 8 days elapsing between the deposition of the egg and the 

 emergence of the resulting fly. The usual period during summer 

 was found to be 10 or 11 days, increasing as winter approached, 

 when over a month might be required. 



