294 



Journal of Agricultural Research voi. xxii. No. 6 



NUMBER OF EGGS 



The only females upon which we have complete recor ds are five moths 

 reared and mated in the insectary. They averaged 315 eggs, the lowest 

 number per moth being 248 and the highest 453. Ten moths brought 

 in from the field averaged 132 eggs, but these had probably laid numerous 

 eggs before they were caught. Under normal field conditions the aver- 

 age number per female is probably between 300 and 400. The records 

 of the individual moths are shown in Tables I and II. 



Table I. — Time between emergence and egg laying, length of egg-laying period, and 

 number of eggs laid by reared specimens of Porosagrotis orthogonia 



E= emerged. D=dead. 



Average period between emergence and egg laying 4 days. 



Average period of egg laying 3 to 4 days. 



Average number of eggs i'^s- 



Table II. — Period of egg laying and number of eggs laid by Porosagrotis orthogonia 

 moths brought in from the field and kept in rearing boxes 



D=dead. 



Average period of egg laying 3 to 4 days. 



Average number of eggs 132. 



DURATION OF EGG STAGE 



The length of the egg stage is exceedingly variable, depending largely 

 upon moisture conditions. It may be as short as 1 1 days or may extend 

 over several months. Eggs laid in the insectary August 19 hatched 

 August 3c. On September 30 several newly hatched larvae were found 



