February, ’20] 
NEWELL: POISONING THE BOLL WEEVIL 
127 
Table II. Per Cent Mortality Among Boll Weevils on Lead-Arsenate Treated Plants: 
(A) Protected from Dew and Rain, and (B) Exposed to Dew and Light Rains, During 
First 10 Days After Treatment 
24-hour period after application 
A 
B 
Protected from dew and rain 
Exposed to dew and light rains 
Treated 
(250 weevils 
in 3 cages) 
per cent 
Check 
(250 weevils 
in 3 cages) 
per cent 
Treated 
(500 weevils 
in 6 cages) 
per cent 
Check 
(500 weevils 
in 6 cages) 
per cent 
1st. 
7.2 
0 
9.0 
1.4 
2nd. 
8.8 
0 
11.4 
1.4 
3rd. 
18.4 
2.8 
12. 
1.2 
4th. 
15.2 
0 
10. 
1.4 
5th. 
9.6 
0.4 
7. 
1.4 
6th. 
9.2 
2.4 
6.8 
2.0 
7th... 
7.6 
.4 
5. 
0.4 
8th. 
3.6 
2.8 
5.6 
1.8 
9th. 
2.4 
2.4 
3.2 
3.2 
10th. 
3.6 
2.8 * 
3.8 
3.0 
Total mortality. 
85.6 
14.0 
73.8 
17.2 
Comparison of the data in the above table is easily made by means 
of the following chart, in which the daily percentage of mortality is 
shown in the case of both the covered plants and those exposed to 
normal deposition of dew and rain. 
day. 123456789 10 
Chart 1.—Daily mortality, in percentages, among weevils on cotton plants treated 
with lead arsenate: heavy line (A), among 250 weevils on plants protected from all 
dew and rain; broken line (B), among 500 weevils on plants exposed to normal deposi¬ 
tion of dew and rain. 
The same information is also contained in the following chart, in 
which “A” shows the total mortality, during the first ten days after 
