February, ’20] 
NEWELL: POISONING THE BOLL WEEVIL 
133 
two lived for 13 days and one for 19 days on dew from lead-arsenate 
treated plants. 
From the foregoing chart it is seen that the mortality was not appre¬ 
ciable until the weevils had been drinking the poisoned dew for more 
PER CENT. 
Chart 5.—Total percentage of mortality among weevils deprived of all food and 
furnished only with: A, dew from plants treated with lead arsenate; B, dew from 
plants treated with calcium arsenate; C, clear water. 
than three days. Therefore, under normal field conditions the mor¬ 
tality caused by drinking dew containing poison is so small that no 
practical degree of control through this cause can be expected. Be¬ 
sides, a careful study of the weevil’s habits indicates no tendency to 
drink dew in such quantities as would be necessary for successful 
poisoning if the weevil secures the poison mainly or entirely in this 
way. 
The following experiments approximated field conditions in that 
weevils were furnished with both dew from treated plants and with 
fresh cotton squares as food. 
