92 



HIBERNATION OF THE COTTON BOLL WEEVIL. 



snout, occurs between the bases of the antennae. When the wing 

 covers and wings are unfolded the abdomen shows seven (Hstinct 

 dorsal segments. The last segment visible from above in the female 

 is called the propygidium. In the female this covers the terminal 

 segment or pygidium, which can be seen only from the sides. 



Male. — Snout slightly shorter, thicker, and more coarsely punctured 

 than in the female. The depression mentioned in the female is lacking. 

 The antennsB are inserted at practically one-third of the distance from 

 the tip of the snout to the eyes. The sides of the snout are very 

 nearly parallel. In the abdomen the male shows eight distinct dorsal 

 segments, the terminal segment (pygidium) not being covered by the 

 propygidium as is the case in the female. 



In general practice an examination of the snout is sufficient to 

 determine the sex of each weevil. 



PROPORTION OF SEXES SURVIVING HIBERNATION. 



The records here given as to the proportion of sexes surviving 

 hibernation are confined to determinations of sex for positively 

 hibernated adults. 



Table XLVI. — Sex ofrveevils surviving hibernation in Texas. 



a Weighted average. 



Wliile these records show considerable variation in the proportion 

 of the sexes for different localities and during different seasons, there 

 is a uniformity in the general preponderance of males. In the total 

 of 9,000 weevils examined 53.6 per cent were males. This proportion 

 corresponds quite closely to that found to exist among weevils enter- 

 ing hibernation (see pp. 16-17). It is evident, therefore, that the pre- 

 ponderance of males in the spring is not due to any superior power of 

 endurance enabling them to hibernate more successfully than females. 

 Apparently there is little, if any, difference in respect to the ability 

 of the two sexes to hibernate successfully. 



