10 



BULLETIN" 231, IT. S. DEPARTMENT OF AGRICULTURE. 



It is important to note that the maximum longevity on water was 

 6 days, on SpJiseralcea lindheimeri 15 days, on Callirrhoe involucrata 

 20 days, on C. pedata 26 days, on Hibiscus syriacus 43 + days, and on 

 cotton 74 days. 



SEX OF ADULTS. 



The material studied during the year was all sexed and the records 

 have been tabulated to show the seasonal abundance and for com- 

 parison of the varieties (Table II). 



Table II. — Relative proportions of the sexes of boll weevils. 



Variety and description of material. 



Male. 



Female. 



Number. 



Percent. 



Number. 



Per cent. 



Grandis: 



Hibernated weevils 



First generation collected. 



Collected in August 



Bred 



Total and average. 



Thurberias: 



Collected in August 



Bred from Thurberia bolls in September 



Bred from cotton in the fall 



Extracted from Thurberia bolls, March, 1914. 



Total and average 



Hybrids: 



c? ThurberixX 9 grandis.. 



Second generation. . . 



Not positive crosses . 

 tfGrandisX 9 thurberix . . 



Second generation. . . 



Not positive crosses . 



Total and average 



Total and average all weevils. 



674 



73 



158 



557 



67.88 

 53.3 

 62.0 

 52.6 



319 

 64 

 97 



500 



32.12 

 46.7 

 38.0 

 47.4 



1,462 



59.8 



40.2 



51.3 

 50.0 

 62.5 

 57.7 



48.7 

 50.0 

 37.5 

 42.3 



123 



56.9 



22 

 21 

 135 

 11 

 15 



59.4 

 42.0 

 51.0 

 45.8 

 57.7 

 51.3 



95 



43.1 



15 

 29 

 130 

 13 

 11 

 19 



40.6 

 58.0 

 49.0 

 54.2 

 42.3 

 4S.7 



221 



50.7 



217 



49.3 



1,809 



1,292 



Separating this material into hibernated and spring or summer 

 bred weevils, there are in the hibernated material 777 males and 402 

 females, or 65.9 per cent males and 34.1 per cent females, while the 

 spring and summer bred weevils numbered 1,032 males and S90 

 females, or 53.6 per cent males and 46.4 per cent females. 



The total of all records to date gives 8,826 males and 6,710 females, 

 or 56.7 per cent males and 43.3 per cent females. 



It is noticeable that there is a larger percentage of females in the 

 variety thurberise and in the hybrids than in the variety grandis. 



REPRODUCTION. 



RELATION OF FOOD TO COPULATION. 



To test the period from emergence to copulation, a number of lots 

 of males and females of the variety A. grandis were separated by 

 sexes immediately after emergence and placed on either cotton 



