107 



the emergence of weevils at Victoria the mean average temperature 

 was Go. 4:° F. For the first two weeks of April it averaged 68.4° F. 

 Weevils left their winter quarters from the middle to the last of 

 April. While the mean average temperature for May was nearly 3° 

 lower than the temperature prevailing at the time of emergence, 

 weevils remained actively at work in the fields. In the fall also 

 weevils remained at work at a lower temperature than that which 

 seems to be necessary to draw them from their winter quarters. The 

 reason for this fact is not apparent, but it is certain that once having 

 left hibernation weevils will remain active at considerably lower tem- 

 peratures. If the temperature becomes too low they remain quiet 

 without taking food for long periods of time. If taken from their 

 winter quarters weevils will be found active at ordinary day tempera- 

 tures long before they would normally venture from their hiding 

 places of their own accord. Weevils thus removed have been kept 

 for a month without food or water, and they then assumed their 

 normal activities when food was supplied to them. 



After considerable search at San Diego in the spring of 1895, on 

 April 27 Mr. Schwarz found the first specimens working upon seppa 

 plants from roots which were then 2 years old. As the weevils first 

 appeared in that localit}^ in August, 1891, the number of hibernat- 

 ing weevils could not have been as great as in succeeding j^ears, 

 and consequently in the spring of 1895 hibernated specimens were 

 ''exceedingly rare." At Victoria, Tex., in the spring of 1902, Mr. 

 Schwarz found the first weevils working upon volunteer plants on April 

 15. In the same locality the writer found, in 1903, that most weevils 

 left their winter quarters between April 10 and May 1. Evidence was 

 found indicating that in some fields they began to move as early as 

 March 28. At Calvert, Tex., also in 1903, Mr. Harris found the first 

 weevils working on cotton on April 12. At Victoria, in 1901, weevils 

 were found in numbers upon seppa plants on March 11, and they 

 were found moving in the field at intervals throughout the winter. 



GRADUAL EMERGENCE FROM HIBERNATION. 



Field observations at Victoria in the spring of 1901 added greatly 

 to our knowledge of the habits of hibernated weevils as they emerge. 

 The opportunities for such observations were exceptionally good. The 

 winter preceding was mild and dry, so that large numbers of weevils 

 hibernated successfully. The same conditions insured the growth of 

 a considerable number of seppa plants, which were also favored by 

 warm weather early in the spring. 



The field in which observations were made contained about 65 acres. 

 On this area all seppa cotton was repeatedly destroyed, except upon 

 two plots which were kept for observations. Plot A, upon which 

 observations in regard to the emergence of weevils were made, was 



