Juue, '10] REVIEWS 321 



Reviews 



The Hibernation of the Boll Weevil in Central Louisiana, by 

 WiLMON Newell and M. S. Dougherty, Louisiana Crop Pest Com- 

 mission, Circ. 31, p. 163-219, 1909. 



In 1905 and '06 the Louisiana Crop Pest Commission carried on extensive 

 experiments on the hlht'rnation of the boll weevil at Keachie, La., in coopera- 

 tion with the Burean of Entomology, which have been partially reported by 

 Hinds and Yothers (Bull. 77 Bur. Entomology). Further experiments were 

 felt to be necessary and these were arranged at Mansura, near the center 

 of Louisiana in the fall of 1908. The authors are entirely warranted in their 

 statements that "The results of these experiments from the standpoint of 

 the Louisiana planter at least, are of far more practical importance than 

 those of any like experiment previously made." The object was to determine 

 what percentage of weevils survive the winter, and at what rate they left 

 their winter quarters in the spring. A series of large wire screen cages 8 x 

 8 X 6 ft. high were constructed in which were placed materials in which the 

 weevils commonly hibernate. From 1000 to 1200 weevils were placed in 

 each cage. A series of cages was installeil to determine the effect of starva- 

 tion in the fall by enforced hibernation. The weevils were placed in the first 

 cage September 28 and a similar cage was started each week until December 

 21. A comparison was also made of a cage under normal conditions and one 

 located in a swamp in a light growth of timl)er. In another cage a large 

 tree-limb bearing Spanish moss was placed to determine its value as a hiber- 

 nating quarter. 



It has been previously stated that the weevils seek hibernating quarters 

 when a mean daily temperature falls to 60° F., but the authors' observations 

 show that the weevils were not inclined to enter hibernation till December 8, 

 altho the mean temperature for ten days preceding was 43°. The writers 

 believe that some of the weevils seen on the sides of the cages remained there 

 thruout the entire winter. In the five cages first started the greatest death 

 rate occurred during the warm weather prior to the date of hibernation. 

 Commencing on February 15, daily observations were made to determine the 

 number of weevils leaving hibernation and these were tabulated in detail. In 

 general, it may be said that the tabulation of the data and results of these in- 

 vestigations is most admirable and leaves nothing to be desired on the part 

 of the student who wishes to give them detailed study. 



In the 16 cages there were 10,281 weevils, 3,300 of which or 20.63 per cent 

 survived the winter. As a result of a comparison of the percentage sur- 

 viving in the cages in which the weevils were confined at different dates in 

 the fall, it is shown that where cotton plants were destroyed before October 

 15, only 3 per cent survived; where it was destroyed between October 15 and 

 27, 15 per cent survived; from November 1 to 25, 22 per cent survived; from 

 November 30 to December 7, 28 per cent survived, and if the destruction of 

 the plants were postponed till after the middle of December, over 43 per cent 

 survived. 



It was found that in the average winter quarters 20 per cent of the 

 weevils survive, but where Spanish moss was furnished, 27.96 per cent 

 emerged from hibernation. A comparison of the cages placed in a swamp 

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