October, '11] CUSHMAX: BIOLOGY OF BOLL WEEVIL 433 



close breeding cages. Nevertheless, eight hundred and sixty-eight 

 weevils, having developmental periods ranging from eleven to nineteen 

 days in duration were reared, and on these the data and conclusions 

 in the following pages are based. 



Methods 



In starting the work eleven hibernated female weevils and as many 

 males taken in the field were used. The females were captured as 

 follows: five on June 21, two on June 22, and four on June 23. These 

 were paired and each pair placed in a tumbler, closed by a square 

 of cheese cloth, with cotton squares from which the involucres had been 

 stripped. The squares were renewed daily and examined for egg punc- 

 tures, the infested ones being placed in breeding jars, each jar contain- 

 ing the squares infested by all the weevils during one day. Throughout 

 the oviposition period careful daily record was kept of the number of 

 eggs deposited and the number of squares infested by each weevil. 

 The female weevils were numbered H. 1 to H. 11 (meaning hibernated 

 weevil No. 1, etc.). The males were removed as soon as oviposition 

 was well under way. H. 1 was discarded from the series on June 27, 

 as it had, up to that time, not oviposited, and H. 4 was thrown out on 

 June 30, having deposited only two eggs. No weevils were reared 

 from the eggs of this individual. 



It was originally planned to use the earliest ten female weevils and 

 the latest ten of each generation throughout the season. The number 

 of generations reared from the earliest females would be the maximum 

 and the number reared from the latest females the minimum number 

 of generations possible during the season. This was carried out to 

 the fourth generation with the earliest females, but of the latest females 

 only those of the first generation were reared. At the time when the 

 last eggs of the latest first generation weevils were being deposited, 

 about the middle of September, the squares from Texas were being 

 used, and very few adults were reared. Moreover, no squares except 

 those from Texas were obtainable, and no attempt was made to carry 

 the work beyond the first week of October. 



Each of the female weevils which were kept for breeding the next 

 generation was labeled with the number of the generation to which 

 it belonged together ^^^th a letter, indicating whether it was one of 

 the earliest or one of the latest of its generation. Thus weevil No. 4.c 

 was the third earliest female weevil of the fourth generation and No. l.y 

 was the next to the last of the first generation. Each female was placed 

 vnih a male in a tumbler, given fresh squares daily, and otherwse 

 treated exactly as were the hibernated weevils. 



