NOTES ON BIOLOGY OF SOME MUSCOID FLIES. JOHNSTON. 91 



Fatten and Cragg (1913, p. 366) reported that in India 

 the egg hatched in 12 hours, the larva matured in from 7 to 21 

 days, and the pupa in about 4 days. Hence the total period 

 from egg deposition to emergence occupied from about 11 to 

 25 days. 



Lyperosia exigua ^leijere. 



The bionomics of the buffalo-fly (a relative of Stomoxys), 

 in the Northern Territory, Avere briefly dealt AWth by Hill 

 (1916). The egg stage occupied 18 to 20 hours ; larval, i.e. 

 from the hatching of the egg to the formation of the puparium, 

 72 to 96 hours ; pupal stage 72 to 120 hours. The life-cycle 

 (egg to emergence) was found under laboratory conditions, 

 in the case of flies reared in March (late summer) to average 

 169 hours (7 days), ranging from 120 hours during warm 

 sultry weather and 192 to 195 when the weather was rather 

 cooler ; while in the case of a fly reared in June when the 

 weather Mas still cooler, 208 hours (nearly 9 days) elapsed. 

 Patton and Cragg (1913, p. 376) state that in India the fly 

 emerges in from 5 to 8 days from the time the eggs are deposited. 



The biology of Lyperosia (or Hcematobia) irritans L. in 

 Europe has been studied by Wilhelmi (1921). Pierce (1921, 

 p. 234) states that in U.S.A. this species, the homfly, requires 

 about 17 days from egg to adult. 



Musca domestica L. 



With the exception of a casual record by Johnston and 

 Bancroft (1920), the only work pubhshed relating to the 

 biology of the common housefly in Austraha is that of Wilhs 

 (1913), though Cleland (1913) has given information regarding 

 the percentage of this species amongst the flies caught in 

 houses in Sydney. Froggatt (1910, p. 246) referred to the 

 stages of housefly development, but there is nothing to indicate 

 that his periods relate to actual observations in Austraha. 



Except in a few cases, no attempt was made by us to 

 determine the length of time passed by the fly in its various 

 developmental stages. It was ascertained that in Eidsvold 

 during November the egg required a day to hatch ; the first 

 instar was passed through in a day ; the second in a similar 

 period ; the third in 3 or 4 days (making a total egg and larval 

 period of 6 to 7 days) ; the pupal stage in 9 to 10 days ; making 

 a total of from 15 to 17 days from oviposition to emergence 

 (Johnston and Bancroft, 1920, p. 5). 



