BIOLOGY OF THE MEXICAN COTTON BOLL WEEVIL. 



43 



in the hibernation cages on November 15 was followed in order of 

 total emergence by the survival of weevils placed in the cages No- 

 vember 1 and December 1, respectively. 



Table XXI. 



-Summary of hibernation of Anthonomus grandis under all con- 

 ditions — winter 1918-19. 





Total 

 num- 

 ber 

 of 

 wee- 

 vils 

 placed 



in 

 cages. 



Open field. 



On ground in woods . 



In trees in woods. 



Total 

 number 

 weevils 

 emerged. 



Total 



Date 

 started. 



Number 

 emerged. 



Per 

 cent- 

 age 

 surviv- 

 ing 

 win- 

 ter. 



Number 

 emerged. 



Per 

 cent- 

 age 

 surviv- 

 ing 

 win- 

 ter. 



Number 

 emerged. 



Per- 

 cent- 

 age 

 surviv- 

 ing 

 win- 

 ter. 



per- 

 cent- 

 age 

 surviv- 





Males. 



Fe- 

 males. 



Males. 



Fe- 

 males. 



Males. 



Fe- 

 males 



Males. 



Fe- 

 males. 



ing 

 win- 

 ter. 



1918. 

 Oct. 1... 

 Oct. 16. . 

 Nov. 1... 

 Nov. 15.. 

 Dec. 1... 



3,000 

 3,000 

 3,000 

 3,000 

 1,100 



1 



17 

 23 

 68 

 14 



1 

 21 

 22 

 59 



9 



0.2 

 3.8 

 4.5 

 12.7 

 7.6 



4 



19 

 115 

 113 

 30 



4 

 22 

 81 

 94 

 27 



0.8 



4.1 



19.6 



20.7 



19.0 







33 



20 



60 



6 





 27 

 18 

 42 



5 







60 



3.8 



10.2 



2.7 



5 



69 



158 



241 



50 



5 

 70 

 121 

 195 

 41 



0.3 

 4.6 

 9.3 

 14.5 

 9.0 



Total.. 

 Av 



13,100 



123 



24.6 



68 



1 



112 



22.4 



59 



1 



5.76 

 12.7 

 0.2 



281 



56.2 



115 



4 



228 



45.6 



94 



4 



12.8 



20.7 



0.8 



119 



23.8 



60 



6 



92 



18.4 



42 



5 



15.34 



60 







523 



104.6 



241 



5 



432 



86.4 



195 



5 



7.54 



Max... 





14.5 



Min... 





0.3 









GENERAL SUMMARY. 



At Madison, Fla., the average longevity of hibernated weevils 

 without food was 12.7 days, and 18.8 days when fed on cotton plant- 

 lets. Adult weevils of the first and second generations lived 24.3 days 

 on cotton squares and 12.3 days on cotton bolls. 



On sea-island cotton plantlets the hibernated weevils lived 11.05 

 days. The first and second generation weevils fed on sea-island cot- 

 ton squares lived 10.7 days, while the weevils fed on sea-island cotton 

 bolls lived only 15.3 days. 



There is practically no difference in the longevity of boll weevils 

 on sea-island and upland cottons. 



The average period from the time the weevils become adult to 

 oviposition at Madison, Fla., for all experiments, was 8.9 days for 

 weevils bred under insectary conditions and 7.07 days for weevils 

 bred under field conditions. 



The average period of oviposition under insectary conditions for 

 all weevils under observation on upland cotton was 33.1 days. The 

 entire series deposited eggs over an average period of 31.7 days 

 on sea-island cotton. The largest number of eggs deposited by a 

 single female weevil was 432. This record was made by a hibernated 

 female on upland cotton squares under insectary conditions. The 

 largest number of eggs deposited during any one day under insectary 

 conditions was 25. This record was also made by a hibernated female 

 weevil. 



