HIBERNATION. 



115 



r-*SUA/£- 



killed all cotton at Brenham by that date. Assuming that it entered 

 hibernation on December 1, it lived six months without food. In 

 another case weevils 



collected in the field r-MAffCtf—^s-ziP/p/L — v ^-m^^- 



in the spring at Cal- 40 

 vert, Tex. , lived with- 

 out food as late as 

 June 8. This gives 

 a duration of life 

 without food of six 

 months and twelve 

 days. Similar ob- 

 servations indicate 

 clearly that the lon- 

 gevity of weevils that 

 pass the winter in 

 artificial cages is a 

 proper index to the 

 longevity of those 

 which pass the win- 

 ter in the field. 



It has become 

 quite apparent from 

 a study of the records 

 that the longevity of 

 weevils provided with food is considerably greater with weevils emer- 

 ging in June than with those emerging in March, while, on the con- 

 trary, with unfed weevils the longevity decreases with the lateness of 

 emergence. (Table LI.) 



The diagram (fig. 25) illustrates the above statement graphically. 



Table LI.- — Latest dates of death of hibernated boll weevils. 



Fig. 25.— Diagram illustrating average longevity of boll weevils after 

 emergin g on a given, date. ( Original. ) 





Unfed weevils. 



Weevils fed foliage. 



Weevils fed squares. 



Time of emergence. 



Mansura, 

 La., 1910. 



Tallulah, 

 La., 1910. 



Mansura, 

 La., 1910. 



Tallulah, 

 La., 1910. 



Mansura, 

 La., 1910. 



Tallulah, 

 La., 1910. 



Feb. 15-28 



Mar. 18 

 Apr. 13 

 Apr. 20 

 Apr. 28 

 May 13 

 May 29 

 June 12 













Mar. 1-15 



Apr. 1 

 Apr. 12 

 Apr. 28 

 May 21 

 June 1 

 June 15 

 June 27 











Mar. 16-31 



June 20 

 July 5 

 June 28 

 July 15 

 July 12 

 July 29 









Apr. 1-15 . . . 



June 21 

 June 18 

 July 15 

 July 26 

 July 7 







Apr. 16-30 













May 16-30 





Sept. 13 





July 19 



July 1 



June 15-30 





Aug. 31 















Entire season 



June 12 



June 27 



July 29 



July 26 



July 19 



Sept. 13 







MAXIMUM LENGTH OF LIFE. 



In connection with Table LI it will be noticed that the latest known 

 recorded death of a hibernated weevil is September 13. This fact, 

 taken in conjunction with Table LII, showing the maximum longevity 



