NOTES ON BIOLOGY OF kSOME MUSCOID PLIES. — JOHNSTON. 77 



Notes on the Biology of some of the More 

 Common Queensland Muscoid Flies. 



By Professor T. Harvey Johnston, M.A., D.Sc, and 0. W. 

 TiEGS, M.Sc, formerly Walter and EHza Hall Fellow in 

 Economic Biology, University, Brisbane. 



{Bead before Royal Society of Queensland, 28th April, 1922.) 



The main object of the present paper is to place on record 

 the results of a series of observations which aimed at deter- 

 mining the duration of the various stages of the hfe-cycle of 

 some of the common Queensland Muscoid flies. Amongst 

 those dealt with are the housefly ; a number of blowflies 

 including certain sheep maggot-flies ; some species of Sarco- 

 jjhaga and Musca ; and the stable fly Stomoxys. 



Observations were recorded regarding the folloA\ing : — - 

 Length of time taken by the egg to hatch ; period during 

 Avhich the larva fed ; time intervening between the cessation 

 of feeding and the undergoing of obvious pupation (larval 

 resting period or prepupal stage) ; length of time passed in the 

 pupal condition ; time elapsing between the deposition of a 

 larva or egg and the emergence of the imago resulting from 

 such larva or egg ; the period between emergence and sexual 

 matm-ity of the female as evidenced by the act of copulation 

 (maturation period) ; time between emergence of the female 

 and oviposition by it (preoviposition period) ; longevitj^ of 

 the adult in captivity. 



The egg period was always obtained by observing the fly 

 actually ovipositing and watching till the eggs hatched, the 

 time being noted in hours. No attempt was made to ascertain 

 the length of time passed in the various larval instars. The 

 resting period was regarded as commencing when the larvae 

 began to leave their food material and to wander. This wander- 

 ing is a marked characteristic of some of the species — e.g. Lucilia 

 larvae are capable of travelhng many yards from the place 

 of feeding until they find a suitable patch of soil in which to 

 pupate ; while Chrysomyia albiceps and Sarcophaga spp. 

 likewise may wander for a considerable distance ; on the 

 other hand Ojyhyra nigra generally bores into the soil directly 

 beneath, or in close proximity to, its feeding place. 



Male flies appear to be sexually mature soon after emer- 

 gence from the puparium, but females usually take some time 



