U. S. D. A., B. E. Bui. 63, Part I. C. B. W. I., January 15, 1907. 



PAPERS ON THE COTTON BOLL WEEVIL AND 

 RELATED AND ASSOCIATED INSECTS. ' 



HIBERNATION AND DEVELOPMENT OF THE COTTON BOLL WEEVIL. 



By E. DwiGHT Sanderson, 

 Formerly State Entomologist of Texas. 



INTRODUCTION. 



The most econoniical method of controlling the boll weevil is to 

 destroy its food supply by burning or grazing the green cotton stalks 

 in the fall before frost occurs, so as to reduce by starvation the num- 

 bers which go into hibernation. As it is known that a large proportion 

 of weevils die during hibernation it may be readily understood that a 

 much greater degree of benefit may be derived by destroying the weevils 

 in the fall than by attempting to destroy them in the spring. The time 

 at which the weevils enter hibernation, the numbers which attempt to 

 hibernate, the mortality occurring during the winter and the factors 

 which influence this mortality, and the time of emergence in the spring 

 are, therefore, matters of practical importance upon which we have 

 made careful observations. 



HIBERNATION. 



DATE OF ENTERING HIBERNATION. 



Table I gives a summary of eight lots of weevils which were con- 

 fined in cages at different dates during October and November, 1903. 

 Altogether some 1,300 weevils were used in these experiments. Begin- 

 ning with October 7 one cage was started each week until November 

 17. On November 18 a sharp freeze occurred, and almost immediately 

 thereafter all weevils went into hibernation. It will be seen that in 

 lots 1, 2, and 3 all of the weevils died prior to November 18. During 

 the beginning of these experiments a plentiful supply of squares was 

 furnished the weevils for food, but as they showed an inclination 

 toward hibernating about the third week in October this supply was 

 discontinued. In all cases the weevils which hibernated successfally 



1 



