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 wen 1 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 XXI II. especially because 

 similarly favorable conditions for determining the full period of 

 emergence in the field may rarely occur. 



LONGEVITY OF 



WEEVILS AFTEE EMERGEN* E IN KEATCHEE 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 emergens from hibernation, without food, at 



Keatchie. La.. 1906. 



Date of emergence. 



190C. 



March 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 2s.... 

 April 30. . . . 



May 1 



May 2 



May 4 



May 5 



Number 

 of weevils 

 emerged. 



Wecvd- 

 days.fl 



02. 

 905. -5 

 751.0 

 678. 5 

 261.0 

 169. 

 100.5 



59.0 



Average 



number 



of days 



lived. 



62.0 

 21.7 

 21.4 

 23.4 

 32.6 

 24.1 

 20.1 

 29.5 



2 



55.0 



27.5 



11 



119.0 



10. S 



9 



92.0 



10.2 



23 





16.4 



6 



132.5 



22.0 



4 



36.0 



9.0 



9 



83.5 



9.2 



3 



24.0 



8.0 



* 



= 



18.5 



IS 



313.0 



17.3 







15.0 



: ■ 



15 



173.0 



11.5 



28 



431.0 



15.3 



19 



342.0 



1S.0 



Number 



Date of emergence, of weevils 

 emerged . 



May 7. 



May 8. . . 

 May 10. . 

 May 11. 

 May 12. 

 May 13. 

 May 14. 

 May 15. 

 May 10. 

 May 17. 

 May is. 

 May 22. 

 May 23. 

 May 25. 

 May 28. 

 May 29. 

 May 30. 

 June 9. . 

 June 19. 



1906. 



Weevil- 

 days. <* 



Average 

 number 



of days 

 lived. 



Totals and 

 aver : 



292. 5 



1.0 

 54. 5 



13.0 



1.5 



_ 



L69.5 

 58 



4v 5 



29.0 

 26.5 



1-5 



,. .i 



35.0 



7.0 

 4.0 



is. 2 



10. 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 



s. 7 



7.0 



4.0 



17.11 



a In the third column of the table theexpression "weevil-days" i- used to signifythe total number of 

 davs lived by the total number of weevils recorded for a certain date. For example 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 1 period, while those emerging toward the 

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

 the lis weevils toted the average duration of life without food 

 proved to be slightly over seventeen days. 



