48 



HIBERNATION OF THE COTTON BOLL WEEVIL. 



examination all weevils were considered as emerging upon the date 

 of the examination, whereas in the cages the weevils were collected 

 daily. The second reason is that upon plants in the field there was 

 a much greater possibility of overlooking weevils which were present 

 and which might be found and counted as having emerged upon 

 some succeeding examinations. Table XXIV is, however, of value 

 in supporting the records given in Table XXIII, especially because 

 similarly favorable conditions for determining the full period of 

 emergence in the field may rarely occur. , 



LONGEVITY OF WEEVILS AFTER EMERGENCE IN KEATCIIIE EXPERI- 

 MENTS. 



For determining longevity after emergence the weevils emerging 

 during short periods were placed together in a smaller cage provided 

 with a variety of rubbish but with no food. Examinations of the 

 small cages were made at frequent intervals and the period between 

 the average date when weevils were placed in the cage and the aver- 

 age date of examinations was recorded. The figures are arranged 

 chronologically according to emergence. 



Table XXV. 



-Longevity of weevils after emergence from hibernation,, without food, at 

 Keatchie, La., 1906. 



Date of emergence. 



Marfh 20. 

 April 10. . 

 April 11.. 

 April 12.. 

 April 13.. 

 April 14. . 

 April 15.. 

 April 16.. 

 April 17.. 

 April 19.. 

 April 20. . 

 April 21.. 

 April 22.. 

 April 23.. 

 April 24. . 

 April 25.. 

 April 26.. 

 April 28.. 

 April 30.. 



May 1 



May 2. . . . 



May 4 



May 5 



Number 

 of weevils 

 emerged. 



Weevil - 



days.o 



02. 

 905. 5 

 751.0 

 678. 5 

 261.0 

 109. 

 100.5 



59.0 



55.0 



119.0 



92.0 



378.5 



132.5 



36.0 



83.5 



24.0 



855.0 



313.0 



15.0 



173.0 



431.0 



342.0 



Average 



munber 



of days 



lived. 



62.0 

 21.7 

 21.4 

 23.4 

 32.6 

 24.1 

 20.1 

 29.5 



27.5 



10.8 



10.2 



16.4 



22.0 



9.0 



9.2 



8.0 



18.5 



17.3 



7.5 



11.5 



15.3 



18.0 



Date of emergence. 



May 7. 

 May 8. . . 

 May 10. . 

 Mav 11.. 

 May 12. . 

 May 13. . 

 May 14. . 

 May 15. . 

 May 16. . 

 May 17. . 

 May 18. . 

 May 22. . 

 May 23. . 

 May 25. . 

 May 28. . 

 Mav 29. . 

 May 30. , 

 June 9. . 

 June 19. 



1906. 



Number 

 of weevils 

 emerged . 



Totals and 

 average 



Weevil- 

 days." 



292.5 



202. 



1.0 



54.5 



13.0 



1.5 



58.5 



26. 



169.5 



58.0 



48.5 



23.5 



29.0 



26.5 



1.5 



7.5 



35.0 



7.0 



4.0 



Average 



niuuber 



of days 



lived. 



7,155.0 



18.2 



16. 3 



1.0 



9.0 



3.2 



1.5 



7.3 



13.0 



13.0 



9.6 



12.1 



11.7 



14.5 



13.2 



1.5 



7.5 



8.7 



7.0 



4.0 



17.11 



oin the third column of the table the expression "weevil-days" is used to signify tlie total number of 

 days lived by the total number of weevils recorded for a certain date. For examjile, if one weevil had 

 lived 10 days, a second 15 days, and a third 23 days the total number of weevil-days for these 3 individuals 

 would be 48 and the average number of days lived would be 16. 



It is noticeable that weevils emerging early in the season survived 

 far longer than the average period, while those emerging toward the 

 end of the season survived for less than the average period. For 

 the 418 weevils tested the average duration of life without food 

 proved to be slightly over seventeen days. 



