PLANTS INSECTICIDAL PROPERTI ES. 
17 
Table 5. — Comparative results obtained by spraying Maerosiphum sp. A with 
alcoholic and benzene extracts derived from "cube" derris, and pyrethrum, 
and with 40 per cent nicotine sulphate. 
Aphids sprayed with alcoholic extracts. 
Aphids sprayed with benzene extracts. 
Esti- 
Percentage of aphids 
Percentage of aphids 
Esti- 
Preparation. 
Num- 
ber of 
mated 
num- 
ber of 
dead within— 
dead within — l 
Num- 
ber of 
mated 
num- 
ber of 
sets. 
indi- 
vid- 
uals. 
6 
1 
2 
3 
6 
1 
2 
3 
sets. 
indi- 
vid- 
uals. 
hours. 
day. 
days. 
days. 
hours. 
day. 
days. 
days. 
Extract +water 
(4+100): 
"Cube".... 
1 
1 
1 
500 
500 
500 
50 
50 
60 
95 
85 
80 
100 
90 
85 
Derris 
95 
90 
Pyrethrum. 
. 
Extract+soap+ 
water (4+2+ 
100): 
"Cube".... 
3 
3 
3 
1,680 
1,500 
1,700 
99 
98 
97 
100 
100 
98 
Derris 
Pyrethrum. 
100 
Extract +soap+ 
water (2+2+ 
100): 
Pyrethrum. 
1 
1 
1 
500 
500 
500 
90 
100 
99 
95 
100 
Derris 
"Cube".... 
100 
Extract+soap+ 
water (1+2+ 
100): 
"Cube".... 

4 
4 
2,500 
2,000 
2,000 
100 
99 
62 
98 
98 
60 
98 
98 
85 
100 
100 
85 
1 
1 
1 
500 
Derris 
100 
76 
500 
Pyrethrum. 
80 
500 
Extract +so a p 
+ water (3/4 
+2+100): 
Pyrethrum. 
1 
1 
1 
500 
500 
500 
30 
93 
100 
60 
98 
70 
100 
Derris 
"Cube".... 
Extract + soap 
+ water (1/2 
+2+100): 
"Cube".... 
6 
3,000 
98 
100 
98 
98 
100 
2 
1,000 
Derris 
5 
2,500 
93 
97 
100 
95 
97 
99 
2 
1,000 
Pyrethrum. 
1 
500 
25 
40 
50 
50 
60 
85 
1 
500 
Extract + soap 
+ water (1/3 
+2+100): 
Derris 
4 
2,000 
77 
82 
89 
95 
50 
85 
92 
1 
500 
"Cube".... 
5 
2,500 
95 
99 
100 
90 
96 
97 
1 
500 
Extract+soap 
+ water (1/4 
+2 + 100): 
"Cube".... 
5 
2,500 
96 
99 
100 
90 
90 
93 
1 
500 
Derris 
2 
1,000 
60 
62 
70 
80 
50 
60 
60 
1 
500 
Extract+soap 
+ water (1/5 
+ 2 + 100) 
"cube" 
2 
1,000 
93 
97 
99 
100 
Extract + soap 
+ water (1/6 
+ 2 + 100) 
"cube" 
3 
1,500 
93 
97 
99 
100 
40 per cent nico- 
tine sulphate 
(l/400)+soap 
+ water (2.5 
+ 2+100) 
6 
3,000 
98 
99 
100 
40 per cent nico- 
tine sulphate 
( 1/800) +soap 
+ water (1.25 
+2+100) 
6 
3,000 
95 
98 
100 
40 per cent nico- 
tine sulphate 
(1/1,200) + 
soap + water 
(0.8+2+100).. 
3 
1,500 
91 
95 
97 
100 
1 Where a test did not continue for 3 days, columns are left blank. 
60635°— 24 3 
