122 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Table VIII shows the summary of observations recorded in Table 

 VI and that the average length of the pupal period was 40.7 days for 

 the 229 pupse. 



Table VIII. — Spring brood of pupae. Summary of pupal periods of Table VI. 



Comparative length of pupal periods of male and female larvse. — 

 An attempt was made to ascertain the sex of the future moth while 

 in the larval state, by the occurrence of two black spots on the 

 dorsum of one of the posterior abdominal segments, the presence of 

 which indicated a male. Records were kept on each individual that 

 could be observed well in its cocoon, and in each instance the moth 

 issued true to the sex ascribed to it while in the larval state. 



In comparing the total pupal periods for 64 males and 87 females, 

 the average length of the pupal stage for males was found to be 40.5 

 days and that of the female to be 40.6 days. This difference was 

 not sufficient to warrant any conclusion during the 1910 season as 

 to the respective lengths of the pupal periods of the males in com- 

 parison with that of the females. 



Temperature conditions. — The temperature conditions influencing 

 the pupal periods of the spring brood of pupse are summarized in 

 Table IX: 



Table IX. — Spring brood of pupse. 



Temperature conditions influencing the pupal 

 period. 



SPRING BROOD OF MOTHS. 



Time of emergence of moths in the spring. — Figure 2 shows graphi- 

 cally the time of emergence and the relative abundance of moths of 

 the spring brood with the corresponding daily mean temperature 

 in degrees Fahrenheit. The records for these observations are given 

 in Table X. 



