20 



BULLETIN 926, U. S. DEPARTMENT OF AGRICULTURE. 



under field conditions. Female weevils liberated in large cages over 

 growing cotton plants frequently get killed accidentally, spiders 

 sometimes catch them, and they escape very readily from the cages. 

 The records presented in Table XI really indicate the rate of oviposi- 

 tion per day instead of the average number of eggs deposited per 

 female. 



Takle IX. — Ef/(/-hi!/i)i<i activity of individual hibernated female boll weevils 

 kept with males under field conditiv>\$ an upland cotton. 



Parent weevil. 



1 feneration. 



No. 





A 1 



Do 



A 2 



Do 



A 3 



Do 



Do 



Do 



Do 



A 4 

 A 5 



A 7 

 A 8 



Do 



A 9 



Do 



A 10 



Do 



A 13 



Do 



Do 



A 14 



A 16 



Date of 

 first egg. 



Date of 

 last egg. 



Total 

 number 

 of eggs 

 depos- 

 ited. 



Aver- 

 age 

 number 

 of eggs 

 per 

 day. 



Maxi- 

 mum 

 number 

 of eggs 

 per 

 day. 



Source of weevils. 



Total. 



Average. .. 

 Maximum . 

 Minimum. 



20 



Mav 

 ...do.... 

 May 31 

 June 1 

 ..do.... 

 June 8 

 June 9 

 June 8 

 ..do.... 

 June 12 

 ..do.... 

 June 18 



June 1 

 June 21 

 June 5 

 June 14 

 June 8 

 June 1.5 

 June 13 

 June 14 

 June 19 

 June 21 

 June 23 

 June 22 



28 

 218 

 33 

 80 

 65 

 63 

 49 

 68 

 70 

 88 

 97 

 54 



76 

 218 

 33 



9.9 

 5.5 

 6.1 

 9.3 



9.7 

 5.8 

 11 

 8.1 



10.8 



8.4 

 11 



168 



Hibernated field collected. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 



LENGTH OF TIME UPLAND COTTON SQUARES HANG ON THE 

 PLANTS AFTER EGG PUNCTURE. 



In Table X are found the data on the length of time squares hang 

 on the plants after egg puncture by the weevil. The average num- 

 ber of days from the time the egg is deposited until it drops off the 

 plant is shown to be 11.5 days. The maximum length of time any 

 square hung on the plant after egg puncture was 19 days and the 

 minimum period 6 days. 



The length of time elapsing from the date of falling of the infested 

 square from the cotton plant to the emergence of the adult weevil is 

 shown to be 10.8 days. Practically one-half of the weevil's immature 

 stage is developed while the square is on the plant. The minimum 

 number of days from falling of the infested square to the emergence 

 of the adult weevil was 3 days and the maximum number 19 days. 



