COTTOJSr BOLL WEEVIL IN THE MISSISSIPPI VALLEY. 



21 



The total eggs per female varied from 2 to 24, with an average of 

 only 9, and the average per day was only 0.3. The oviposition period 

 ranged from 6 to 61 days, with an average of 29 days. 



These results indicate the great difficulty with which oviposition is 

 performed when only bolls are offered for food, but at least a large 

 percentage of the eggs deposited were fertile, as 20 adults were reared 

 from them. 



Fecundity of Mhernated thurheriae females on cotton holls. — Nine 

 pairs of thurheriae weevils were extracted from their hibernation cells 

 in Thurberia bolls on July 27 and placed with cotton bolls at once. 

 They were offered only this food until death. The results are given 

 in Table XV. 



Table XV. — Fecundity of hibernated Anthonomus grandis thurheriae on cotton bolls. 





Date 

 ovipo- 

 sition 

 began. 



Date 

 ovipo- 

 sition 

 ended. 



Ovipo- 

 sition 

 period. 



Eggs deposited— 



Maxi- 



Date Installed. 



Nor- 

 mally. 



Exter- 

 nally. 



Total. 



per 

 day. 



July 27 



Aug. 11 

 July 28 

 Aug. 15 

 July 28 

 Aug. 4 

 July 28 

 Aug. 4 

 Aug. 18 

 July 30 



Sept. 18 

 Sept. 5 

 Aug. 28 

 Aug. 20 

 Aug. 18 

 Sept. 24 

 Aug. 16 

 Sept. 9 

 July 30 



Days. 

 39 

 41 

 14 

 24 

 15 

 59 

 13 

 23 

 1 



1 

 1 

 1 

 6 

 2 

 1 

 4 

 1 



62 

 1 

 1 

 8 

 5 

 2 

 1 

 1 

 1 



63 

 2 

 2 



14 

 7 

 3 

 5 

 2 

 1 



7 



Do 



1 



Do 



1 



Do.i 



3 



July 27 



2 



Do - 





Do 



2 



Do 



1 



Do - 



1 









Total 







204 



25.5 



59 



1 



11 



L3 



4 



74 



9.3 



62 



1 



85 



10.6 



63 



1 



















7 





















1 Tliis female escaped Aug. 20, and consequently is not included in the averages. 



One of these females escaped, and consequently only eight are 

 considered in the averages. These eight deposited a total of only 

 85 eggs, and 74, or 89.4 per. cent of these were deposited externally. 

 It is striking that every female that deposited any eggs laid one or 

 more externally. This is positive evidence of the unsuitabihty of 

 bolls as food for these weevils. 



The average total eggs per female was 10.6 and the average num- 

 ber deposited normally was only 1.3. These eggs were fertile, how- 

 ever, as several adults were reared from them. 



Fecundity of (/randis females on cotton hoUs and squares on alternate 

 days. — In addition to the foregoing studies on the effect of cotton 

 bolls on the deposition of females another series was conducted in 

 which each female was offered squares and boUs on alternate days. 

 These females were bred individuals, which were fed squares until 

 normal deposition started. Consequently this series does not show 

 the effect of the boU food upon the fecundity of the females, but 



