103 



northeastern part of the cotton belt with that of Victoria, Tex., dur- 

 ing the six months from June 1 to November 30, 1902, naturally 

 reveals a considerable range of difference, as does also a comparison 

 of the average temperatures prevailing in those localities during the 

 same period for the preceding eleven years. Wherever it is con- 

 sidered in its effect ujDon the development of the weevil the tempera- 

 ture given is expressed in degrees of effective temperature — that is, 

 the actual temperature above 43° F. The mean average effective 

 temperature for any month multiplied by the number of days included 

 has been considered as giving the total effective temperature for that 

 month. While this method does not give exactly the correct figures, 

 it will furnish data for a comparison of the various localities, and this 

 study of temperatures will undoubtedly reveal facts which will exert 

 considerable influence upon the status of the weevil in other localities 

 into which it is liable to spread. 



The total effective temperature for Victoria, Tex., from June 1 to 

 November 30, 1902, was 6,607° F. For the same period at Dallas, Tex., 

 it was 5,626° F., and at Atlanta, Ga., it was 5,052° F. 



The average mean total effective temperatures for the sections of 

 Texas, Louisiana, and Georgia, as given by the Weather Bureau for a 

 series of eleven years, are as follows: Texas, 5,716°; Louisiana, 5,578°; 

 Georgia, 5,234° F. 



The effect of this decrease in temperature will doubtless be in some 

 measure counteracted by a certain degree of adaptation thereto on 

 the part of the weevil, but it still seems probable that in the tempera- 

 ture of Georgia a considerable reduction in the number of generations 

 will be found. The emergence from winter quarters will probable be 

 considerabty later than the middle of April. The development of 

 progeny will not be as rapid as has been described for Victoria, Tex., 

 in preceding pages. Furthermore, it seems likely that during the 

 warmest periods the life cycle will require from 22 to 28 days. The 

 consequent limited number of generations in a season will be still 

 further curtailed by the earlier period of hibernation, which it seems 

 will begin as early as the latter part of October or the first of Novem- 

 ber, instead of during December, as was the case during the past two 

 years at Victoria. The date of the killing frosts will, in a general 

 way, fix the end of the active season for the weevil, and this will 

 therefore vary considerably from year to year. 



