38 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Egg deposition by individual moths. — Already during 1910 several 

 experiments had been made to-determine the number of eggs deposited 

 by a single female. The results from these observations were, how- 

 ever, limited to a few females and could not be considered conclusive. 

 Further efforts were therefore made in 1911 to obtain additional data 

 on this question. Many difficulties have been encountered in getting 

 moths that will oviposit in captivity. The obstacles have probably 



Fig. 14. — Emergence curve of moths of the spring brood in 1911, at Douglas, Mich. (Original.) 



been due to the fact that mating had not taken place, it being difficult 

 to find the insects in copulation or to bring about mating by confining 

 together single pairs of male and female moths. In the stock-jar 

 cages, where a number of male and female insects have been confined, 

 eggs have always resulted in abundance and mating must have occurred 

 quite generally though it was only observed on rare occasions. It 

 was therefore planned to remove female moths from the stock jars 

 after the moths had been confined together two or three days, and 

 prior to any egg deposition in the stock jars. 



