ENTRANCE INTO HIBEENATION. 19 



of the weevils seem to have left the plants. This decrease may be 

 attributed to several factors. First, the weevils were gradually 

 leaving the plants through flight, wliich may have carried them out- 

 side the fields, and, second, many were seeking and remaining in 

 shelter which was to be found upon the ground within the field. A 

 hard freeze preceded by low temperatures during several days occurred 

 on November 19. However, the examinations made on November 

 20 and 22 showed many weevils present in the frozen squares and 

 especialh' upon the bolls. It is apparent that these weevils did not 

 immediately leave the plants, but remained upon the bolls and 

 squares as long as the latter might serve as a food supply. But 

 within a few days all squares and foliage became perfectly dry, and 

 after this especially weevils became less active. The numbers wliich 

 were found upon the plants after December 1 may be considered in 

 a rather strict sense as in hibernation. The shelter which they could 

 obtain was comparatively slight, and in the last examination, made 

 on January 21, about 25 per cent of the weevils found upon the bolls 

 still hanging to the stalks were dead. 



In reference to Table II attention may be called to the exceptionally 

 large number of weevils found at Wharton in one field on November 

 14. This was a field of about 5 acres in extent, and at the time it 

 was examined the plants were exceptionally large and very luxuriant 

 in growth, showing an abundance of squares. Very few bolls had 

 been set, so that the entire growth of the plants seems to have been 

 turned to the production of squares. As has been shown in pre- 

 ceding paragraphs, such conditions would favor directl}^ the produc- 

 tion of an abnormally large number of weevils per acre. The fact 

 that more than 6,000 weevils were actually collected in tliis field 

 makes it even more certain that the estimate given, while possibly 

 high, is not impossible. It may be considered as representing fully 

 the maximum number of weevils which it is possible for an acre of 

 cotton to support even under conditions which are most favorable 

 to their development. Another series of examinations made before 

 and after the freeze referred to at Dallas in a preceding paragraph 

 should be considered in connection with Table III as serving to show 

 the correlation between the disappearance of the weevils from 

 the plants and their occurrence under shelter on the ground during the 

 period when they are entering hibernation. 



