116 



THE MEXICAN COTTON-BOLL WEEVIL. 



of weevils from the time of entering hibernation to death, is of great 

 interest. The maximum longevity of 335 days, or 11 months, gives 

 proof of the wonderful vitality of the boll weevil. 



Table LII. — Longevity of hibernated boll weevils from installation to death. 



Place. 



Condition. 



Longevity. 



Average. 



Maximum. 



ra, La., 1010.. 

 Tallulah,La.,1910.. 



M:insura, La., 1010.. 



.:.. La., 1010.. 



tfansura, La., 1010.. 



Tallulah, La.,1910.. 



Unfed 



do 



Fed foliage.. 



do 



Fed squares. 

 do 



Days. 



l-> 



221 



257 

 262 



Days. 



226 

 243 

 256 

 272 

 267 

 335 



RELATION OF EMERGENCE AND LONGEVITY TO TIME OF 



PLANTING. 



The data that have been presented show the extreme importance 

 of early planting as a means of averting damage by the boll weevil. 

 Early planting takes advantage of the portion of the season when the 

 weevils are present in the fields in smallest numbers. The longer 



Elanting is deferred the greater the number of weevils which will 

 ave emerged. The advantage of an early crop has been shown in 

 many experiments by the Bureau of Entomology and by practical 

 cotton planters. On the other hand, the experience in late plantings 

 has been disastrous. The obvious explanation is in the prolonged 

 period of emergence and the remarkable ability of the weevils to live 

 without food after emergence. This topic vail receive additional 

 treatment under the heading of " Repression. " 



NATURE OF WEEVIL ACTIVITY FOLLOWING EMERGENCE FROM 



HIBERNATION. 



In the section dealing with the spring movement we have discussed 

 the early search of the weevils for food. There are certain points 

 connected with the spring movements, however, which are intimately 

 related to hibernation, and these will be dealt with here. 



1 In folio wing the activity of emerged weevils at Dallas, Tex., 

 certain specimens were marked in such a way as to make it possible to 

 recognize them individually, and the weevils were allowed to remain 

 practically undisturbed in the section where they had spent the 

 winter. In making the daily examinations record was kept of the 

 appearance or disappearance of each individual weevil. No food was 

 supplied in any of the sections until toward the close of the experi- 

 ments in May, when seed was planted and cotton began growing 

 before the last weevils emerged. A majority of the weevils were 

 seen a second time, and some disappeared and reappeared as many 

 as eight times. The longest period between the nrst and secona 

 appearance of any individual was 43 days. 



1 From Bull. 77, Bureau of Entomology, pp. 50, 51. 





