38 



HIBERNATION OF THE COTTON BOLL WEEVIL. 



and Dallas, while at Victoria the period between Deceml)er 1 and 15 

 was more favorable. 



The shelter conditions within which weevils survived was also 

 determined in these experiments, and the principal points are shown 

 in the following table, which again does not include cotton-seed tests : 



Table XVI. — Shelter in which surviving weevils tvere found in April and May, 1906. 



This shows the favorable nature of old corn and cotton stalks, 

 among which the survival in one cage at Calvert was surprisingly 

 large. It also indicates that weevils may survive in varied shelter, 

 and that in all probability the temperature and moisture conditions 

 experienced may be as important as the nature of the shelter in 

 determining survival. 



LARGE-CAGE EXPERIMENTS, KEATCHIE, LA., 1905-6. 



With the work of 1905-6 a change was made in the method of 

 carrying on the hibernation experiments. Instead of using numer- 

 ous small boxes in a number of places, large screen-covered cages were 

 utilized in the fields at Keatchie, La., and Dallas, Tex. The Keatchie 

 cage (PL III, fig. 2) was constructed under the direction of Mr. 

 Wilmon Newell, secretary of the State crop pest commission of 

 Louisiana and special field agent, cooperating in the boll weevil 

 investigations. It was probably the largest structure of its kind 

 that has ever been built for an entomological investigation. The 

 interior was divided by partitions into eighteen sections. The 

 shelter conditions for the weevils and the dates upon which weevils 

 were inclosed were planned to represent the extremes of field condi- 

 tions as to shelter and date of entrance into hibernation. The gen- 

 eral plan of the experiment is shown in the first section of Table 

 XVII, and in the last section are included the emergence records for 

 the cage. 



Before entering upon a discussion of the work at Keatchie special 

 credit should be given Mr. Wilmon Xewell and his assistant, Mr. J. B. 

 Garrett, who were particularly concerned in the execution of the 

 work at Keatchie. Much work has also been done by Mr. W. D. 

 Hunter upon the reports of the Keatchie experiments in arranging 

 the data so as to show the most significant facts. 



