34 



Tabi.r VII. — Length of life of tveevils upon squares. 



Whether we include the time of hibernation or not, it appears from 

 the averages of 156 hibernated weevils that those which winter suc- 

 cessfully are longer lived than any following generation, as their 

 active life in spring averaged fully 80 days for males and 70 for 

 females. Probably the greater activity of the first generation may 

 account for their somewhat shorter life. The average active life 

 period for all generations is probably not far from 71 days for males 

 and 64 daj's for females. 



LENGTH OF LIFE ON BOLLS ALONE. 



As weevils appear to feed freely on bolls in the field after the period 

 of maximum infestation has been reached (PI. I, fig. 10), these tests 

 were made to determine whether they might be able to live normally 

 with no other food. 



A number of weevils were placed upon bolls as soon as they became 

 adult. Others which had first been fed upon squares were given bolls 

 after they had become hard and had shown themselves to be in a nor- 

 mally healthy condition. Of the total 37 weevils thus tested, 16 were 

 males and 21 were females. The males showed an average length of 

 life of 19.7 days, while the females survived for only 15.2 days. This 

 is a much shorter period than the normal length of life ui^on squares 

 for either sex. 



LENGTH OF LIFE ON COTTON LEAVES ALONE. 



To determine whether they could live upon the foliage of cotton 

 alone 69 newly transformed weevils were at the 1st of October, 1902, 

 placed upon fresh leaves, which were renewed at frequent intervals. 

 During the first three weeks 52 of these weevils (21 male and 31 

 female) died, leaving 17 alive and well; 11 of these were then returned 

 to squares and 6 continued upon the leaves. Of these 6, 3 lived to be 

 81 days old and were then intentionally killed for dissection. The 



