62 



HIBERNATION OF THE COTTON BOLL WEEVIL. 



of weevils from shelter. During the last week of January and the 

 first week of February the lowest temperatures of the winter occurred 

 at Dallas and Calvert. The counts made immediately after this 

 period showed the smallest number of active weevils recorded at any 

 time during the winter for those two localities. At Victoria the tem- 

 perature was not sufficiently low to produce any marked decrease in 

 weevil activity. During the remainder of February there was a 

 rather steady rise in temperature throughout the State and many 

 weevils continued active. The figures show that during the last 

 week of the month considerable numbers were emerging from their 

 winter shelter; and beginning with March 1 the period of general 

 emergence is considered to have begun. 



While these three charts show plainly the conditions existing during 

 the winter of 1906-7, proving beyond question that during this 

 season there was no such thing as complete hibernation of the boll 

 weevil in Texas, it must not be understood that this is frequently the 

 case. No other such season has occurred since the weevil entered Texas. 

 As a rule, hibernation is complete during the period of from four to six 

 months. It is certain that weevils may continue their activity 

 throughout the season wherever climatic conditions are not sufficiently 

 severe to entirely destroy the growth of cotton. 



ACTIVITY DURING NORMAL PERIOD OF HIBERNATION. 



The general impression as to the activity of weevils during the 

 normal period of hibernation has been shown in figures 3 to 5. A 

 summary of the records for the three locations, with the temperature 

 conditions prevailing at the time of each examination, is shown in 

 Table XXXI. 



Table XXXI. — Activity during normal kibcrnation period, 1906-7. 



DALLAS. 



a This total represents 7.8 per cent of all the weevils put in the cage. 



