RECENT STUDIES OF THE MEXICAN COTTON BOLL WEEVIL. 15 



Table VI. — Fecundity of females of A. grandis in copula only one time and not fertilized. 



Total, average, 

 etc. 



Time 

 in cop- 

 ula. 



Oviposition. 



Total 

 eggs. 



Eggs deposited. 



Eggs per day. 



Time 

 from 



Started. 



Ended. 



Period. 



Exter- 

 nally. 



Nor- 

 mally. 



Aver- 

 age. 



Maxi- 

 mum. 



last 

 egg to 

 death. 





Min. 



3 



7.5 

 19 

 37.5 



June 29 

 June 30 

 July 1 

 ...do.... 



June 29 



Aug. 26 

 July 1 

 July 3 



Days. 



1 



58 



1 



3 



1 



67 

 3 

 3 







51 











1 

 16 

 3 

 3 



1 



1.1 

 3 

 1 



1 

 6 

 3 

 1 



Days. 



4 





1 









35 







Total.. . 



67.0 

 16.7 



63 

 15.7 



74 

 18.5 



51 



23 







48 



Average 











12 



Weighted av- 











1.1 

 3 



1 









..... 



58 

 1 



67 

 1 



51 

 



16 



1 



6 



1 



35 







1 







1 





From Table V it is seen that the greatest fertility was with the 

 longest period of copulation (45 minutes). Beyond this there seems 

 to be very little relation between the time in copula and the resulting 

 degree of fertility. In the infertile females it is seen that periods of 

 25 and 37.5 minutes in copula still failed to result in fertility. 



The total eggs deposited by the fertile females ranged from 32 to 

 456 with an average of 235 each for the five females. This average 

 is quite high, even in comparison with females having males present 

 throughout life. The infertile females deposited from 1 to 67 eggs, 

 with only one depositing more than 3 eggs. 



The period of fertility of the fertile females ranged from 19 to 44 

 days with an average of 32.6 days. The average eggs per day ranged 

 from 1.2 to 8.5 with a weighted average of 6.4. This is a rather high 

 average when compared with the results secured in other deposition 

 series . 



A comparison of these results seems to indicate that the time in 

 copula has very little influence on the resulting fertility of the female. 

 One female was not rendered fertile during 37.5 minutes of copulation 

 while four others were fertilized in less than this time. The shortest 

 time in copula which resulted in fertility of the female was 24 minutes, 

 but the writer thinks that this is not significant. 



The high average of the eggs deposited by the females fertilized 

 only once would seem to indicate that one fertilization is sufficient 

 to produce the maximum fecundity of the female. While this may 

 be true in certain rare instances, the writer believes that such cases 

 will be very rare. In a different breeding series a few females were 

 allowed to deposit eggs from one fertilization until they stopped 

 deposition, then males were added and in every case the females 

 began depositing again and continued for some time. The female 

 with the highest deposition record in the one fertilization series 

 discussed above quite evidently reached the limit of her fertility 17 

 days before death and she deposited 9 infertile eggs in this period. 



