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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
application, on plants entirely protected from dew and rain and “B” 
the total mortality on plants exposed to light rains and normal deposi¬ 
tion of dew. Ai and Bi show, respectively, the total natural mortality 
among weevils confined under identical conditions but on non-treated 
plants. 
Chart 2.—Diagram showing total percentage of mortality among boll weevils on 
cotton plants treated with lead arsenate: A, on plants protected from all dew and 
rain; B, on plants exposed to normal precipitation. Also natural mortality among 
weevils on non-treated plants: Ai, on plants protected from all dew and rain; Bi, 
on plants exposed to normal precipitation. 
Identical experiments were made using calcium arsenate, instead of 
lead arsenate, as the poison and using the same check cages. The 
following table shows the results obtained wdien using calcium arsenate, 
instead of lead arsenate, the arrangement of cages, method of applica¬ 
tions, etc., being the same. 
i 
