92 



HIBERNATION OF THE COTTON BOLL WEEVIL. 



snout, occurs between the bases of the antenna 1 . When the wino- 

 covers and wings are unfolded the abdomen shows seven distinct 

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



is -ailed 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, 

 antennae 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 a- i- the case in the female. 



In general practice an examination of the snout i- 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 of wet vils surviving hibernati&i 



Year. 



1903.. 

 1904.. 

 1904.. 

 1904.. 

 1906.. 

 1907.. 

 1907.. 

 1907.. 



Locality. 



Several places . 



Calvert 



Victoria 



do 



do 



Dallas 



Calvert 



Victoria 



Mai.'. 



Number 

 deter- 

 mined. 



Total and average. 



209 



40 



42 



I'd 



84 



1,068 



94S 



1,660 



Percent- 

 age of 

 total ex- 

 amined. 



60.0 

 7 



55.0 

 59.6 

 54.2 

 53.0 

 61.3 



Female. 



Number 

 deter- 

 mined. 



174 

 27 

 21 

 132 

 57 

 ,412 



• 

 ,049 



Percent- 

 age of 



total ex- 

 amined. 



39.3 

 40.0 

 33.3 

 45.0 

 40.4 

 " 5 

 47.0 



a56.7 



3,718 



a 43. 3 



a Weighted average. 



While 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 female-. 

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

 of the two sexes t<> hibernate successfully. 



