■R 
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Kerosene extracts of derris were much more toxic then kerosene 
alone. The addition of smell Quantities of derris extract to 
pyre thrum extract apparently gave 'a significant increase in toxicity. 
■Whether the toxicity of the kerosene extract of derris was due to 
rotenone is a question. Certainly rotenone was present. Jones and 
Smith ( 157 ) report that the solubility of rotenone in kerosene at 
20° C. is less than one-tenth of 1 percent. Possibly extractives 
.of derris. other than rotenone contributed to the toxicity of the 
kerosene extract. Derris apparently contains some kerosene-soluble 
■ ■■■-. compounds, .which add considerably to the toxicity of the kerosene 
toward houseflies. 
3ock-(35). in 1934 reported that an aqueous extract of derris, 
made into a sirup with sugar, proved lethal to flies that fed on it. 
The active constituents of this extract were soluble in ether. The 
marc from the aqueous extract gave even more effective extracts with 
alcohol and ether. Large dosages caused regurgitation. 
Campbell, Sullivan, and Jones (53,54) in 1934 reported the 
results of a comprehensive study of kerosene extracts of derris 
root as housefly sprays. Kerosene extracts of four samples of 
derris root, three of cube root, and one of haiari stems were tested 
■ against houseflies by a modified laboratory method. All were ef- 
fective. The extracts of "derris were On the whole more effective 
than those of cube. The extract of haiari stems was the least 
effective. Rotenone is not the only toxic component of kerosene 
extracts of these plant materials, but it appears to be an important 
one. Methoxyl content may be a better chemical index of the insecti- 
cidal value of ro'tenone-bearing plants than rotenone content. 
Deguelin, tenhrosin, and toxicarol were tested in alcoholic solution 
in comparison with rotenone. Deguelin was nearly as effective as 
rotenone, tephrosin sLightly effective,' and toxicarol ineffective. 
.These investigators also made comparative tests of extracts of der- 
ris and of pyrethrum against houseflies. Comparable kerosene ex- 
'■■--■ -tracts of, good samples, of derris root and of pyrethrum flowers 
. - -were tested against houseflies in a small glass chamber, in Pect- 
G-rady chambers, and in rooms, The pyrethrum extracts w^re more 
effective in paralyzing flies, the derris extracts were more 
effective in killing them. It was believed that kerosene extracts 
of derris have practical possibilities as housefly sprays. 
Dibble (73) in 1934 recommended a cattle spray made by soaking 
1/2 pound of ground pyrethrum flowers in 1 gallon of mineral spirits 
for 48 hours. Water solutions containing pyrethrum and derris were 
tried but with indifferent success. They ".-orked more slowly and 
probably killed fewer flies. 
The. United States Department of Agriculture,' Bureau of Entomology 
(239 ) , in 1934 reported that kerosene extracts of roots of derris, 
cube, and Tephrosia virginiane , end of haiari stems, tested against 
houseflies, led ■ to the following conclusions: Rotenone is not the 
only toxic component of kerosene extracts of rotenone-bearing plants, 
but it appears to be an important one. A given weight of derris root 
