54 HIBERNATION OF THE COTTON BOLL WEEVIL. 



Table X_X.lX. — Emergent* records for one-half -acre field cU Victoria, Tex., 1906. 





Number of weevils found. 







Date of examina- 

 tion. 



- 

 - 



— 



— o 



s- ~ 



— 



— 

 _ - 



E-r 



- - 



p a 



: i 

 -- 



Remarks. 





346 

 358 



492 

 .- 

 165 

 731 



<? | 9 



d" 



? 



d 



? 



346 

 358 



492 

 355 

 228 

 739 



Weevils not removed. 







M .. 25 













Do. 



May 28.a 













\V> .'. Us marked yellow=492. 



June 13 



129 



27 

 3 













marked blue=22(i. 



June23-Julv 5 



July 23-26.. 



9 

 



IS 

 



9 



1 









2 



2 



Weevils marked white = 7v 









Total 



2,31S 



159 9 



IS 10 



2 



2 



2,518 





o Eighty-seven weevils removed from field May 28 for other experimental work. 



It is evident from an examination of the number of weevils found 

 that the number in the field increased steadily until after June 5. 

 Between June 5 and 13 a large number of previously marked weevils 

 appeared, all of which were undoubtedly hibernated. The very 

 small number of first-generation weevils which was found upon the 

 examination made between June 23 and July 25 was due primarily 

 to the exceptionally severe hot dry weather which had prevailed for 

 several weeks. The gradual decrease in the number of living hiber- 

 nated weevils was greater than the increase in the number of first- 

 generation weevils. During the period between the middle of June 

 and the middle of July the plants rapidly increased their fruiting 

 activity and there was a decided decrease in weevil injury. It is 

 interesting to note that in spite of the large number of hibernated 

 weevils occurring in this field, which threatened early in the season 

 to prevent entirely the setting of fruit, the weevil injury and devel- 

 opment were so checked by the heat and drought that after the 

 middle of Jury these plants set fruit rapidly and the field produced 

 an average yield of cotton. 



The most plausible explanation of the late period of emergence for 

 weevils found in this field is the existence in its immediate vicinity 

 of a large number of trees which were loaded with long Spanish moss. 

 (See PL II, figs. 1, 2.) The explanation of the effect of this moss in 

 producing late emergence from hibernation will be considered more 

 particularly in connection with the cage experiments in hibernation 

 for 1006 to 1907. 



