PLANTS IXSECTK'IDAL PROPERTIES. 
21 
Table 8. — Effects of spraying aphids with the sap and alcoholic extracts of II urn 
crepitant. 
Sample 
No. 
Preparation. 
Iosects tested. 
Percentage of aphids dead 
within — i 
Esti- 
mated 
number 
of indi- 
viduals. 
Num- 
ber of ] 
sets. 
species. 
6 hours. 1 day. 
1 Aphis sp. A 
1 Aphis sp. B 
1 Macrosiphumsp. A.. 5 
1 Aphis sp. A 
2 days. 
3 days. 
500a 
512a 
523 
524 
500 Sap 10 per cent 
.500 Do 
-xp 20 per cent 
500a Sap -r soap -f water (5 
per cent +4+ 100). 
Do 
Sap + soap — water 
(10percent-2-100; 
Control, soap— water 
(2+100). 
Control, soap + water 
(4-100). 
Do 
Alcoholic extract of 
bark — soap — water 
(2-2-100). 
Alcoholic extract of 
sawdust + soap ■+- 
water (2+2+100). 
Control, alcohol + 
soap-rwater (2+2+ 
100). 
40 per cent nicotine 
sulphate (11200)+ 
soap— water (0.8+ 
2-100). 
100 
100 
500 
100 
100 
2,000 
500 
100 
100 
1,000 
1,000 
500 
1,500 
1 Aphis sp. B 
4 Macrosiphum sp. A . 
do 
Aphis sp. A 
Aphis sp. B 
Macrosiphum sp . A . . 
.do. 
.do. 
.do. 
30 
20 
91 
: 
15 . 
92 . 
100 
1 Where no test was taken, and where a test continued only 2 days, blanks are left. 
DISCUSSION OF THE LESS IMPORTANT RESULTS OBTAINED. 
A powder and decoction of the common yarrow (Achillea mille- 
folium) had no effect on the aphids (Macrosiphum sp. B) tested. 
The roots, leaves, and stems of Columbia monkshood (Aconitum 
columhianum) , used as a stomach poison, had no effect on grass- 
hoppers ; and used as a dust, they had no effect on bee-. 
The leaves of a peach tree (Amygclalus persica), wet with the 
juice of mulberry-tree leaves, were fed to silkworms, and within 24 
hours after eating this food practically all of the insects were dead. 
A water extract of ahiliton (see footnote on p. 26) had no effect 
on silkworms. 
Cold and hot water extracts of sagebrush (Artemis?*/ tridentata) 
had no effect on silkworms, webworms. potato-beetle larva 1 , rose 
aphids, and nasturtium aphids. but these extracts slowly killed bees. 
A water extract of ariiliton (see footnote on p. 26) had no effect 
against small webworms and small catalpa caterpillars. Water and 
alcoholic extracts were efficient against bees. The powder, used as a 
fumigant. had no effect against small webworms; used as a dust, it 
had a slight effect on tent caterpillars and roaches: and used as a 
stomach poison, it had no effect on webworms and flies and only a 
slight effect on roaches and silkworms. 
A water extract of balbec (see footnote on p. 26) killed silkworms 
quickly. 
The juice, highly concentrated, from the green leaves and beans of 
catalpa ( [Catalpa bignonioidcs) had a slight effect on bees. 
