85 



weevils working on cotton on April 12. At Victoria, in 1904, weevils 

 were found in numbers upon seppa plants on March 1-4 and they 

 were found moving in the field at intervals throughout the winter. 



From these observations it appears that normal emergence takes 

 place usually some time in April, whether the first or tlie last of the 

 month depending largely upon the earliness of the, season. Further- 

 more, the emergence of the first weevils may take place from two to 

 four weeks before that of the last. In this fact lies one of the two 

 great obstacles which prevent the successful application of poisons 

 to the early cotton as a means of destroying the weevils. The second 

 obstacle is explained on pages 41-43. 



Owing to the empty condition of the alimentarj^ canal, hibernated 

 weevils are able to fly with ease, and this they must do in their search 

 for food. Doubtless many perish soon after emergence, even if they 

 find food which many others never succeed in reaching. 



APPARENT DEPENDENCE OF REPRODUCTION UPON FOOD 

 OBTAINED FROM SQUARES. 



During the fall of 1902 a series of experiments, lasting for 12 weeks, 

 was made to determine the length of life of weevils fed solely upon 

 leaves. In one lot, consisting of 9 males and 8 females, the average 

 length of life of the females was 25 days, while that of the males was 

 3G daj^s. Though this period far exceeded the normal time usually 

 passed between the emergence of adults and the beginning of egg 

 deposition, no eggs were found. Dissection of the females which 

 lived longest showed that their ovaries were still in latent condi- 

 tion, though the weevils were then 81 days old. Few instances of 

 copulation were observed among weevils fed upon leaves alone, and 

 among nearly 70 weevils which were thus tested, no eggs were ever 

 deposited. After a period of 3 weeks upon leaves, 11 weevils were 

 transferred to squares. Females in this lot began to lay in 4 days, 

 and 4 of them deposited 323 eggs in an average time of 20 days. The 

 conclusion seems plain that so long as leaves alone are fed upon 

 eggs do not develop, while a diet of squares leads to the development 

 of eggs in about 4 days. It is worthy of note that the interval 

 between the first feeding upon squares and the deposition of the first 

 eggs is almost the same with these weevils taken in middle life as 

 with weevils which have just emerged. 



An examination of hibernated females taken in the spring of 1903, 

 which had fed for G weeks upon cotton leaves, showed that their 

 ovaries were still latent. Copulation was rarely observed among 

 hibernated weevils until after squares had been given them. In a few 

 days after feeding upon squares, mating and oviposition began. The 

 average period was from 3 to 5 days, and having once begun, ovipo- 

 siMon continued regularly. 



It has been found that food passes the alimentary canal in less than 



