HIBERNATION IN THE POTATO BEETLE. 



399 



with the immense decrease in the fat content which likewise 

 results at this period. 



RECOVERY FROM HIBERNATION. 



In the preparation for hibernation the potato beetles pass 

 through a quiescent phase which has been designated as pre- 

 hibernation. Likewise on emergence from dormancy there is a 

 period of quiescence known as recovery. From results obtained 

 on respiratory metabolism during recovery and before feeding, 

 it is evident that the increase in CO 2 output is very gradual, 

 lasting for six days (Fig. n). The examples upon which the 













0010 

 0003 

 .0008 

 .0007 



.0006 

 0005 



* .0004 



.0003 

 .0002 

 .0001 



n .oooo 



Days 



1 



2 



3 



4 



FIG. ii. Ordinates show the average COz output per hour per gram body 

 weight of beetles during recovery from hibernation. This figure is based on group 

 of beetles hibernating for six months. 



above figure is based, comprised a group of beetles in hibernation 

 for six months. After varying periods of dormancy, if potato 

 beetles are removed from the ground and placed with food, we 

 find they require from six to thirty days for recovery before 

 feeding. Those that have been in hibernation for over two 

 months require 30 days, those for three months 12 days, and 



