BIOLOGY OF THE MEXICAN" COTTON BOLL WEEVIL. 27 



DEVELOPMENTAL PERIOD OF THE BOLL WEEVIL IN GREEN 



COTTON BOLLS. 



Owing to the fact that large numbers of adult weevils in the field 

 at the time the bolls are set deposit eggs in the bolls almost as readily 

 as they do in the squares, it is almost impossible to secure noninfested 

 bolls for breeding purposes. Therefore the following method for 

 securing the developmental period of the weevil in cotton bolls for 

 upland, long-staple, and sea-island cotton was followed. 



Large, healthy, grown bolls were examined for egg punctures. The 

 number of egg punctures was recorded on a light string tag, together 



Fig. 11. — Green cotton bolls bagged in muslin to secure records on the immature stages 

 of the weevil, Madison, Fla. 



with the date of examination. The boll was inclosed in a thin muslin 

 bag to prevent further infestation and allowed to remain on the plant 

 under normal field conditions until the adult weevil emerged. All 

 weevils that emerged were counted and the sex determined. 



During the month of August 200 weevil-infested bolls were bagged 

 (fig. 11) on each of the three types of cotton. Daily examinations 

 were made of the bagged bolls after a period, of 10 days had elapsed. 



The upland cotton bolls produced 7 male weevils that required 233 

 weevil days for development, or an average period of 33.2 days. The 

 6 female weevils bred from upland cotton bolls required a total of 

 207 weevil days, or an average period of 34.5 days from egg to adult. 



The 200 long-staple or thick-rind cotton bolls produced 8 male 

 weevils that required 250 weevil days from egg to adult, or an average 



