PLANTS INSECTICIDAL PROPERTIES. ^3 
a slight effect on catalpa caterpillars, while an alcoholic extract 
from it had no effect on small webworms and tulip-tree aphids. 
A water extract of lancepod (Lonchocarpus sp.) had no effect on 
silkworms. 
The powder from the common matrimony- vine (Lycium halim/'fo- 
lium), used as a dust, affected roaches considerably, but tent cater- 
pillars only slightly ; and used as a stomach poison, it had a consid- 
erable effect on grasshoppers. The water extract did not affect bees. 
A commercial powder containing Madhuca sp. seeds was tested 
and found efficient but slow against silkworms, although within 48 
hours it killed only about 35 per cent of the Aphis spp. A and B 
tested. A decoction of the powder had only a slight effect on the 
same species of aphids. 
A water extract of the wood of moetoepoe (see footnote on p. 26) 
proved to be efficient, while a water extract of the leaves was found 
to be inefficient against silkworms. 
A water extract of the leaves of necoetae (see footnote on p. 26) 
killed silkworms very slowly. 
The powder from the leaves and stems of the common oleander 
(Xerium oleander) and a decoction from this powder had no effect 
on aphids (Macrosiphwm sp. B). 
An infusion and a decoction of the leaves of tree tobacco 
(Xicotiana glauca) with soap (1 pound to 50 gallons of water) had 
only a very slight effect on nasturtium aphids, while the powdered 
leaves had no apparent effect on them. (An analysis of some of 
the leaves, made by a chemist of a tobacco by-products company, 
showed that the nicotine content, upon a moisture-free basis, 
amounted to only 0.18 of 1 per cent). 
The hot and cold water extracts of the bark and leaves of 
Pangium edule were found to be inefficient against tent caterpillars. 
The extracts from the bark appeared a little better than those from 
the leaves. 
Neither the exhalation nor decoction from the green leaves of 
Pongam pinnata had any effect on nasturtium aphids. 
A hot-water extract from the green tops of the American elder 
(Sambucus canadensis) had no effect on silkworms, webworms, or 
rose aphids. 
A powder and a decoction from the whitetop-aster {Sericocarpits 
asteroides) had no effect on the aphids (Macrosiphum sp. B) tested. 
The water extract of the horsenettle (Solanum earolmense) had 
no effect against small webworms and small catalpa caterpillars. 
The powder, used as a fumigant, had no effect against small catalpa 
caterpillars; used as a stomach poison, it had no effect against silk- 
worms and webworms, but had a slight effect on grasshoppers ; and 
used as a dust, it had a slight effect on tent caterpillars and roaches. 
The powder from sleepy grass {Stipa virldula), used as a dust, 
had no effect on tent caterpillars, but had a slight effect on roaches. 
A water extract of the bark of suma rubra (see footnote on p. 26) 
had a slight effect against silkworms. 
A water extract of tssikoena (see footnote on p. 26) had a slight 
effect against silkworms. 
The powdered roots of Veratrum californicum had no effect on 
grasshoppers. 
