HIBERNATION. 



115 



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 



40 



collected in the field 

 in the spring at Cal- 

 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 



{>roper index to the 

 ongevity 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. 



35 



30 



\20 



Q 



/5 



/O 



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

 emerging on a given date. ( Original. ) 



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



Time of emergence. 



Feb. 15-28. 

 Mar. 1-15.. 

 Mar. 16-31 . 

 Apr. 1-15.. 

 Apr. 16-30. 

 May 1-15. . 

 May 16-30. 

 June 1-15. . 

 June 15-30. 



Entire season. 



Unfed weevils. 



Mansura, 

 La., 1910. 



Mar. 18 

 Apr. 13 

 Apr. 20 

 Apr. 28 

 May 13 

 May 29 

 June 12 



June 12 



Weevils fed foliage. 



Tallulah, Mansura, 

 La., 1910. | La., 1910. 



Apr. 1 

 Apr. 12 

 Apr. 28 

 May 21 

 June 1 

 June 15 

 June 27 



June 20 



July 5 



June 28 



Julv 15 



Julv 12 



July 29 



Tallulah, 



La., 1910. 



June 21 

 June 18 

 Julv 15 

 Julv 26 



July 7 



June 27 July 29 | July 26 



Weevils fed squares. 



Mansura, 

 La., 1910. 



July 19 



July 19 



Tallulah, 

 La., 1910. 



Sept. 13 

 July 1 

 Aug. 31 



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 



