32 
BULLETIN 1147, U. S. DEPARTMENT OF AGRICULTURE. 
ducting the mortalities of the controls and basing the average per- 
centages of toxicity on the mortalities of the third, sixth, tenth, and 
twentieth days, the results for all these insects are: Sample 69, 45; 
sample 69A (sample 69 plus 0.5 gram lime), 32.7; sample 69B (sample 
69 plus 1 gram lime), 29.1 ; sample 69C (sample 69 plus 2 grams lime), 
26.5. 
Table 14. 
-Effect on toxicity of adding lime to arsenicals on 4 species of insects, 1919 and 
1920. 
Arsenicals and control. 
Percentage of insects dead within— 
a 
days. 
6 days. 
6 
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39C 
69C 
64 
64C 
39 
Commercial acid lead arsenate. 
Sample 39 plus lime (2 grams) . . 
Laboratory calcium arsenate. . . 
Sample 69 plus lime (2 grams). . 
Commercial Paris green 
Sample 64 plus lime (2 grams).. 
Commercial acid lead arsenate. 
Sample 39 (leaves sprayed with 
91.0 
69.0 
32.7 
9.4 
100.0 
57.0 
11.0 
6.3 
5.4 
1.8 
30.7 
1.8 
20.3 
20.5 
7.5 
2.3 
.0 
1S.1 
18.0 
42.3 
33.3 
65.7 
23.4 
21.0 
14.0 
12.0 
7.0 
15.0 
8.0 
35.3 
26.8 
23.1 
12.9 
52.8 
22.5 
100.0 
93.0 
53.8 
15.1 
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72.8 
38.3 
39.7 
14.4 
85.2 
44.2 
79.0 
78.7 
30.4 
12.2 
.0 
82.2 
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91.6 
91.2 
99.0 
86.0 
58.0 
40.0 
44.0 
23.0 
62.0 
56.0 
78.3 
63.1 
57.3 
35.9 
86.6 
66.3 
39L 
57 
Commercial calcium arsenate. . 
57 L 
Sample 57 (leaves sprayed with 
Control with food 
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.0 
.0 
8.8 
12.0 
Arsenicals and control. 
Percentage of insects dead 
within 10 days. 
Toxicity for— 
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99.3 
82.9 
66.0 
30.2 
100.0 
99.4 
93.6 
95.1 
66.0 
36.4 
2.6 
100.0 
100.0 
98.8 
100.0 
100.0 
100.0 
99.8 
94.3 
74.8 
50.9 
100.0 
99.8 
97.0 
87.3 
48.7 
15.7 
100.0 
78. 7 
61.0 
42.5 
37.0 
15.5 
72.0 
48.5 
64.3 
64.7 
34.6 
17.0 
66. S 
66.4 
77.6 
74.8 
S8.2 
69.8 
39.5 
27.0 
28. 
15.0 
38.5 
32.0 
66.1 
39C 
69 
69C 
64 
Sample 39 plus lime (2 grams) 
Laboratory calcium arsenate 
Sample 69 plus lime ( 2 grams) 
Commercial Paris green 
100.0 
59.6 
22.6 
55.8 
47.8 
30.2 
74.7 
64C 
39 
Sample 64 plus lime (2 grams) 
Commercial acid lead arsenate 
100.0 
57.2 
39L 
Sample 39 (leaves sprayed with 
sample 1 1 lime) 
57 
Commercial calcium arsenate 
57L 
Sample 57 (leaves sprayed with 
sample 1 1 lime) 
Control with food 
.0 
23.1 
1 Based on mortalities for third and sixth days only, because these controls, confined iu small pases, 
lived for only 8.4 days on an average. 
In 1920 these experiments were repeated on a larger scale The 
following data are not given in Table 14: Silkworms, 2 sots (each of 
50); webworms (H. cune.a), 1 set (variation 136-194: 145); tent 
caterpillars, 3 sets (198-385: 280); and honeybees, 2 sets (each of 
50). The percentages given for samples 69 and 690 are taken from 
the 1919 results, and should be compared only roughly with the Other 
percentages given in Table 14. Reference to this table shows that 
