BIOLOGY OF THE MEXICAN COTTON" BOLL WEEVIL. 



21 



Table X. — Showing development of tceevil as related to the length of time 

 squares hung on plants after egg puncture, eggs deposited, by hibernated females 

 on upland cotton. 













Aver- 











Aver- 





Total 



Total 

 number 

 days on 

 plant 

 after 

 punc- 

 ture. 



Mini- 

 mum 



Maxi- 

 mum 



age 

 number 



Total 



Total 

 number 

 days 

 from 

 falling 



to 

 adult. 



Mini- 

 mum 



Maxi- 

 mum 



age 

 number 





number 



number 



number 



days 



number 



number 



number 



days 



Date oviposition 



squares 



days on 



days on 



from 



squares 



days 



days 



from 



began. 



under 



plant 



plant 



punc- 



under 



from 



from 



falling 





obser- 



after 



after 



ture to 



obser- 



falling 



falling 



of 





vation. 



punc- 



punc- 



falling 



vation. 



to 



to 



square 







ture. 



ture. 



of 





adult. 



adult. 



to 













square. 











adult. 



May 29 



29 

 100 

 24 

 33 

 24 

 23 

 12 

 42 

 51 

 28 

 36 

 • 19 



315 



1,125 

 269 

 400 

 307 

 265 

 148 

 482 

 514 

 289 

 410 

 240 



7 

 6 

 8 

 6 



10 

 7 

 6 

 7 

 7 

 6 

 6 

 9 



15 

 18 

 16 

 17 

 19 

 17 

 15 

 19 

 13 

 16 

 16 

 19 



11.6 

 11.2 

 11.2 

 12.1 

 12.7 

 10.6 

 12.3 

 11.4 

 10.7 

 10.3 

 11.3 

 13.6 



12 



17 

 9 



11 

 2 

 7 

 2 

 9 

 8 



14 

 7 

 4 



122 



185 



82 



108 



21 



79 



22 



105 



107 



156 



83 



39 



7 

 7 

 7 

 3 



10 

 7 



10 

 9 



10 

 9 



10 

 9 



12 

 15 

 11 

 13 

 11 

 16 

 12 

 16 

 16 

 19 

 15 

 11 



10.1 



May 27 



1Q.8 



May 31 



9.1 





9.8 



Do . 



10.5 



June 8 



11.2 



June 9 



11 





11.6 



Do 



13.3 



June 12 



11.1 



Do 



11.8 



June 18 



9.7 







Total 



421 



4,764 



85 



7.08 



200 

 16.6 



11.5 



102 



8.5 



1, 109 



98 



8.1 



167 

 13.9 







10.8 



Maximum 







10 

 6 



19 

 13 



13.6 

 10.3 



17 

 4 





10 

 3 



19 

 11 



13.3 



Minimum 







9.1 











FECUNDITY RECORDS OF HIBERNATED FEMALE BOLL WEEVILS 

 ON UPLAND COTTON UNDER FIELD CONDITIONS. 



The data on the fecundity of hibernated female weevils under 

 field conditions are presented in Table XI. Of the progeny produced 

 by the individual female weevils 73 males required 1,536 weevil days, 

 or an average period of 21.7 days, for development from egg to adult. 

 A total of 52 female weevils required 1,145 weevil days, or an average 

 period of 20.2 days, for development of the immature stage. The aver- 

 age period of development for both sexes under actual field conditions 

 was 21.7 days, with a maximum of 24 and a minimum of 19.5 days for 

 the first-generation weevils. A total of 17.99 per cent of the infested 

 squares produced adult weevils. This percentage is remarkably low 

 compared with the generally accepted belief that approximately 

 35 per cent of the infested squares produced adults. At Madison 

 the Norfolk sandy soil is so well drained that the developing weevils 

 are exposed to terrific heat during the time the square is on the soil 

 before the adult weevils emerge. Consequently a very large mor- 

 tality occurs among the immature stages of the weevil. 



