— 4 2 — 



adult state, to allow the body to harden, and the insect to become 

 fitted for active life. But in this case the quiescent period after 

 the adult form is reached is not only of long duration but appears 

 to be necessary to the life of the insect. For in every case where 

 the soil in the breeding-cages was disturbed after the insects had 

 transformed, the beetles perished in the soil. The only way in 

 which we have been able to rear active adults, has been to leave 

 the soil in the breeding-cages undisturbed from midsummer till 

 the following spring. 



This experience clearly indicates that by fall plowing we can 

 destroy the beetles in the soil, and thus prevent their maturing 

 and depositing eggs the following season. 



In closing this report the writer wishes to acknowledge the 

 efficient aid, in the work of the station, of his assistant, Mr. M. 

 V. Slingerland. 



John Henry Comstock. 



