52 



MASS. EXPERIMENT STATION BULLETIN 189. 



definite data were secured as to the number of females fertilized by each 

 male. Bearing in mind the long period of adult Ufe, however, it is prob- 

 able that each male will fertihze several females. 



Proportion of Sexes. 



First Generation. 



A total of 317 first generation pupse were collected from the field in 



July, 1918, and confined in individual cages. From these a total of 317 



first generation adults emerged, of which 136, or 42.9 per cent, were 



males, and 181, or 57.1 per cent, were females (see Table XIV). 



Table XIV. — Proportion of Sexes and Time of Emergence of Moths, 

 First Generation. 



Date of Emer- 

 gence, 1918. 



July 23, 

 July 24, 

 July 25, 

 July 26, 

 July 27, 

 July 28, 

 July 29, 

 July 30, 

 July 31, 

 August 1, 

 August 2, 

 August 3, 

 August 4, 

 August 5, 

 August 6, 

 August 7, 

 August 8, 

 August 9, 

 August 10, 

 August 11, 



Number 



of 

 Males. 



Number 



of 

 Females, 



Total 

 Emer- 

 gence. 



Date of Emer- 

 gence, 1918. 



August 12, 

 August 13, 

 August 14, 

 August 15, 

 August 16, 

 August 17, 

 August 18, 

 August 19, 

 August 20, 

 August 21, 

 August 22, 

 August 23, 

 August 24, 

 August 25, 

 August 26, 

 August 27, 

 August 28, 

 August 29, 

 Total, 



Number 



of 

 Males, 



Number 

 of 



Total 

 Emer- 

 gence. 



Total emergence, 317 adults. 

 Total males, 136, or 42.9 per cent. 

 Total females, 181, or 57.1 per cent. 



A total of 49 first generation pupa were reared from full-grown, first 

 generation larva) collected in the field during July, 1918, in order to secure 

 data as to duration of the pupal period. From this material a total of 49 

 first generation adults emerged, of which 19, or 38.8 per cent, were males, 

 and 30, or 61.2 per cent, were females (see Table IV). 



