1907 - Sanderson, E. D. Hibernation and development of the cotton- boll weevil. U.S.D.A. 

 Bur. Ent. B. 63:1-38, 6 fig. 



Since many cotton boll weevils die during hibernation, it was thought wise to 

 study the effects of various conditions during hibernation upon the mortality of the 

 weevil. It appears that the weevils cannot be forced into hibernation until the mean 

 average temperature drops below 60°F. If, therefore, the weevils are deprived of 

 food during the fall, the percentage of mortality among them may be greatly in- 

 creased. 



The cotton worm is considered of some benefit in this regard, since its 

 chief attack is made upon the cotton plant late in the season, thus destroying the 

 leaves and other edible parts upon which the weevils might otherwise feed. The 

 same result may be brought about by cattle grazing. 



The mortality of cotton boll weevils during hibernation is so great in some 

 instances that not more than 2^% to 15% survive. The maximum rate of mortality 

 in weevils occurs in Dec. or Jan. and is increased by large rainfalls. 



The emergence of the maximum number of weevils takes place in Texas 

 from May 20 to June 1. Notes are given on various other points in the biology of 

 the cotton boll weevil, including summer broods, rate of increase, injury to cotton 

 squares, etc. The relation of temperature and other weather conditions to the 

 hibernation of the insect is given special attention. 



1909 - Hinds, W. E., and W„ W. Yothers. Hibernation of the Mexican cotton boll weevil. 



U. S. D. A. Bur. Ent. B. 77:106, 10 pi., 9 fig. 



A detailed report of extensive investigations of the hibernation of the cotton 

 boll weevil conducted from 1902 to 1907 in Texas and Louisiana. The first part of 

 the bulletin (p. 11-25) discusses the entrance of the weevils into hibernation. 

 Shelter during hibernation is discussed at some length. 



1910 - Newell, W., and M. S. Dougherty. The hibernation of the boll weevil in central 



Louisiana. La. Crop Pest Comn. C. 31:163-219, 1 pi., 5 fig. 



An investigation of the hibernation of the boll weevil extending from Septem- 

 ber 15, 1908, to July 15, 1909, and conducted at Mansura, Anoyelles Parish, La., 

 is reported in detail. The results and conclusions are summarized: 



Out of 16,281 adult boll weevils confined in 16 cages, 3,360, or 20.63%, lived 

 throughout the winter successfully. Destruction of all cottonplants before October 

 15 resulted in only 3% of the weevils surviving the winter. Letting the cotton 

 plants stand in the field until about Christmas resulted in over 40% of the weevils 

 living through the winter to attack the next crop. Starvation of the boll weevils 

 before they entered hibernation in the fall was more effective in causing their 

 death than was cold or wet weather during winter. The average time that the 

 weevil remained in hibernation was 159 days. The extreme length of time that 

 any weevil lived without food while in hibernation was 255 days, or 8j months. 

 When the cotton plants are allowed to stand in the fields until killed by cold, the 

 average weevil has to go without food only about 90 days. When cotton plants are 

 destroyed before October 12, the average weevil must go over 6 months without 

 food or starve to death. Early destruction of the cotton plants results in starva- 

 tion of hordes of boll weevils. 



Spanish moss sheltered an enormous number of boll weevils during the 

 winter. Of the weevils that spent the winter in Spanish moss, 38% survived. Of 

 those hibernating in average materials, only 20% lived. Boll weevils passing the 

 winter in moss emerged from hibernation much later than those hibernating in 

 other materials. Moss-covered trees near the cotton fields increase weevil in- 

 festation. The length of time that the weevils live after leaving hibernation in 

 spring has an important bearing on the problems of poisoning the weevil and of 

 when to plant the crop to best advantage. The average overwintering boll weevil 

 lived 10.7 days after leaving winter quarters. The maximum length of life after 

 leaving hibernation was 44 days. 



The authors consider these results to be indicative of the weevils' hiber- 

 nating habits in most of the alluvial territory in the Mississippi, Red River, 

 Black River, and Ouachita valleys of Louisiana, as Mansura has practically the 

 same prevailing temperatures, elevation, and rainfall. 



140 



