AND HABITS OF THE YELLOW DUNG-FLY. 



645 



The minim«m time from adult to adult observed was 17 days 

 and the maximum 31 days. The average time from the table 

 given above is 24 days, but this time, as stated earlier, is governed 

 by temperature and the consistency of breeding media. 



In one batch of larvse bred in dry dung the larvae were 

 observed to have collected in one spot where the only moisture 

 was. These did not reach the third instar until after a week of 

 larval life. They w^ere transferred to fresh dung later, so that 

 the total larval life was not observed. Under similar conditions 

 the larval life may take as much as three times as long as the 

 maximum observed. 



Text-figure 14. 



Pupavium. 



Sexual maturity is not reached until after 21 days of adult life. 

 During this time the males have no attraction towards the 

 females, and, owing to the male being the more robust, the latter 

 are liable to be attacked unless a sufficient supply of food is 

 maintained. 



Copulation takes place about two days before oviposition. The 

 life of the male is considerably longer than that of the female. 

 No definite results were obtained on the life of the female. No 

 females were observed to lay more than 120 eggs. It is pro- 

 bable that one female is ca^mble of laying from 100 to 150 

 eggs and then dies. Eggs are laid in one batch of from 40 to 80 

 and afterwards, 10 or 20 at a time at intervals. 



The total life-cycle from egg to egg takes from six to seven 

 weeks. » 



