112 





Table XXVIII. 



— Sum in ai 



v ?/ of distances and directions. 





Direction. 



Distance. 



Direction. 



Distance. 



North 



Feet. 



530 

 662 

 682 

 293 



South 



Feet. 



643 







185 



East 



West 



160 







383 









Whether it be merely an unrelated coincidence, or a general result 

 from similar factors in each case, it is interesting to note that the 

 diagram of general movement of weevils as found in this field of seppa 

 cotton is strikingly similar in outline to the present area of weevil 

 infestation. Merely to show this interesting likeness, and not because 

 the likeness has any special significance, an outline of the weevil- 

 infested area is also given in figure 1. 



From the records of these observations it was found that the maxi- 

 mum time one weevil remained upon a single plant was 18 or more 

 days, the observations having been discontinued after the eighteenth 

 day. The average time positively found in 73 cases was 4 days, 

 with a possibility for this same number of observations of 6f da\-s. 

 Probably a true average lies approximately between these results, 

 and, if so, we may assume that about 5^ days usually intervene between 

 the movements of each weevil. In the whole series of observations, 

 extending over 25 daj-s, for weevils which were subsequently found 

 after being liberated, but 57 movements were recorded. The total 

 of these movements averaged but 62 feet each in 177 movement da.ys. 

 This would give us an average movement of but 0.35 foot per day for 

 each weevil in a field where seppa plants were quite abundant, where 

 squares were forming upon fully one-third of the plants, and during 

 a period for which the mean average temperature was 78.6° F. 



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 

 36 days. 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 1 of them deposited 323 eggs in an average time of 20 days. The 



