EMERGENCE FROM HIBERNATION, 1907. 



77 



doubled, and an increase of 50 per cent was observable between 

 November 5 and 14. After November 14 hibernation might have 

 been successful for practically the maximum possible proportion of 

 weevils. The relation of these figures may be most simply expressed 

 in the following manner: Under similar conditions of shelter, but 

 without a food supply, if the survival of weevils in Texas for October 

 15 is one, for October 25 it will be two; for November 5, four; and for 

 November 15, six. These figures make it evident that from October 

 15 to November 15 constitutes the strategic period for attack upon the 

 boll weevil. The attack can be made in two ways : (1 ) By the destruc- 

 tion or removal of the conditions favorable for the shelter of the 

 weevil through the winter; (2) by the destruction of the food supply. 

 These conclusions have frequently been stated and are here repeated 

 because the facts here presented prove more conclusively than have 

 any other data heretofore obtained the unquestionable importance 

 of fall work in combating the boll weevil. The benefit, obviously, 

 will always be realized during the following season by a much smaller 

 injury to the crop. Considerations, both of minimum expense and 

 of maximum effectiveness, emphasize this conclusion. 



SURVIVAL OF WEEVILS BY LOCALITIES AND CAGE SECTIONS. 



In practically all of the sections it may be considered that the 

 emergence period began during the last few days of February and 

 the first few days of March, March 1 being, approximately, the 

 average date in each case. In the following table the summaries of 

 the sectional records in each locality are given, together with the data 

 necessary to show the xnaximum length of the hibernation period and 

 the percentage of survival in each section: 



Table XXXIX. — Maximum hibernation period and percentage of survival by sections, 



1906. 



