30 



PAPEKS ON THE COTTON BOLL WEE\T:L, ETC. 



not fall for about 10 days and remains green long after the hatching 

 of the egg, which takes place in about 2.5 days, there seems no reason 

 to suspect any considerable mortality at this period. After the infested 

 squares have dried or decayed it becomes very difficult to find any 

 trace of larvae which die before the}" are half or two-thirds grown. 

 The table shows that in about 63 per cent of the infested squares no 

 trace of weevil stage could be found. In this percentage are the 

 squares which had received feeding punctures onl}^ and a large num- 

 ber showing external signs of egg punctures, thus indicating that a 

 great mortality occurs while the larva3 are less than half grown. Fur- 

 thermore, it will be observed that of those individuals which pass the 

 larval stage succesfully 1.6 per cent died in the squares or while emerg- 

 ing. It has previousl}" been shown that only about 1 per cent of 

 squares placed where full}" exposed to sunshine developed Aveevils. 

 It w"ould therefore appear that the mortality was largely due to the 

 squares becoming so dried that the food supply was cut off from the 

 young larva. Hence, it w^ould seem that the sooner the square falls 

 after being punctured, the higher will be the mortality, provided the 

 ground is not shaded by close rows, and that any means for knocking 

 off* the squares before they would naturally fall, or a variety or strain 

 of cotton which sheds its squares more quickly after being* punctured, 

 will be of decided advantag^e in increasinof the mortalitA" of the weevil. 

 This seems to be even more marked where the squares are covered by 

 the soil as is shown in Table VI. 



Table TI. — Percentage of mortality oftveevils in squares buried in soil. 





Date. 



Depth 

 buried. 



Condition. 



a> 

 u 



a 



t-l 



a 



Per cent dead. 



Per cent 

 alive. 



il 



(2:a 





S-i 





 ^■-' 



as 

 CO 



> 





u 

 sS 

 3 



GQ 



G 

 "> 







"> 



a) 





 H 



> 



8 

 a, 



cc 



0" 



CO 



'> 

 0) 







CD 

 U 



cc 



s 



£ 







a 

 2 



1 



Aug 15 



do 



do 



Aug. 29 



do 



Sept. 21 



do 



Sept. 11 



do 



Sept. 18 



Jul V 1.5, 1904. 



do 



do 



do 



do 



h inch 



1 inch 



Kept moist in laboratory. 

 do '. . 



«?5 

















40 



? 



«25 

 a25 

 a 25 























46 



? 



I5 inches. 



do 























s-> 



4 



1 inch . 



do 



79 



4 

 "2 



"4 





4 

 12 











24 

 38 



20 



5 



I5 inches 



do 



a 25 28 



44 



76 



b88 



clOO 









16 



6 



l^inches.. 

 2i inches.. 

 4 inches 



In field 



50 74 



78 75 



8 

 4 







8 



7 



Rather dry 



4 













6 



8 



do 



200 

 180 









A 



On surface 

 do 



In sun 



85 



15 

 26 

















 







B 



do 



174 [62 

 400 91 

 400 94.5 

 40081 

 400 92. 5 

 400 95 



12 



















C 



do.... 



1 inch 



2 inches 



Under screen 















9 



q 



Rather wet 









3 



10 



5 



3 













'>5 



10 



do 



















9 



11 



3 inches . 



do 



















? 5 



1'> 



4 inches . . 



do 









6.5 











1 5 































a Contained larvae or pupse when buried. 

 bDead weevils eaten by ants; squares green. 

 c Auts' nest just beneath. 



