10 BULXJETIN 1201, u. B. DEPARTMENT OF AGRICULTURE. 
and had a slight effect on bees (Xo. 100, Table 1) and tent cater- 
pillars, and on Aphis spp. A and B (No. 502, Table 2) ; used as a 
decoction (Xo. 502a, not altered), it had no effect on the same species 
-.1' aphids (Tabic 3); used as a fumigant (No. 502), it killed only 
7r> per cent of the Macrosiphufn sp. C tested, besides the one lady- 
beetle and one of the five large webworms tested; and used as a 
stomach poison, it was efficient but slow against grasshoppers and 
silkworms (Xo.' 109, Table 1). 
The hot and cold water extracts, alcoholic extract, and distillate 
from white hellebore were efficient but slow against silkworms, al- 
though a 0.5 per cent solution of veratrine in weak sulphuric acid 
Killed the silkworms more quickly. The alcoholic and benzene ex- 
tracts, used with soap (Xos. 508 and 517, Table 4). were inefficient 
against four species of aphids (Aphis spp. A and Z?, Macrosiphwm 
sp. .1. and M. liriodendrt) . 
The powdered roots of white hellebore and the hot-water extract 
of these (not commercial) were found efficient but very slow against 
silkworms, although they had no effect on rose aphids. 
COMPARATIVE RESULTS DISCUSSED. 
Powders dusted upon or fed to six specie* of insects. — "Reference 
to Table 1 shows the following: Of the five powders dusted upon 
roaches, sabadilla and pyrethrum kill quickly and seem almost 
equally efficient; derris has no practical value; and since hellebore 
and amianthium, although efficient, kill so slowly, they can not be 
recommended as satisfactory roach poisons. 
Relative to the four powders fed to and dusted upon grasshop- 
pers, all were effi ient, but only pyrethrum killed quickly, and for 
practical purposes none of these can replace the arsenicals as grass- 
hopper poisons. 
Of the five powders fed to and dusted upon silkworms, only derris, 
amianthium, and pyrethrum killed quickly, although hellebore and 
sabadilla were efficient but slow. 
Relative to the four powders used against flies, pyrethrum seems to 
be the best dust, but derris is a close second. Used as a stomach 
poison, amianthium killed all the flies tested within four or five 
days: and amianthium used as a dust killed all of them within four 
days. 
Of the three powders dusted upon honeybees, sabadilla and amian- 
thium killed them comparatively quickly, while hellebore acted 
slowly. 
Of the three powders dusted upon potato-beetle larvae in a potato 
patch, pyrethrum acted the most quickly, although all the larvae 
dusted with derris, "cube," and pyrethrum were dead within -J 1 
hours. 
Powders dusted upon aphids. — Reference to Table 2 shows the 
following: Used as dusts, sabadilla, amianthium, and hellebore had 
no practical value against two species of aphids (ApMs sp. .1 omit- 
ted for these powders). Pyrethrum was efficient against all five 
species of aphids tested: while "cube** was efficient against four out 
of five species, and derris against three out of four species tested. 
Powders used as fundgants. decoctions } infusion*, and hot-water 
extracts* — Reference to Table 3 shows the following: Used as fumi- 
