- Ik - 
aa.ueous suspension (rotenone l:Uo,000) made by adding an acetone extract 
of derris to water killed 6j.l percent of these aphids in 2h hours. 
Granett ( 133 ) in 1335 used Dean aphids in testing the insec'ticidal 
values of derris marcs extracted with certain water-soluble and water- 
insoluble solvents. Ethyl alcohol was the only solvent which removed 
practically all the insecticidal substances from derris. 
C-insburg and Granett (12U) in 1935 reported on the aphicidal 
^ror>erties of derris and cube roof. Derris and cube, as finely ground 
dusts, water suspensions, and extracts, were tested against various 
species of aphids. Tests against A. rumicis with derris samples ranging 
from to 9 percent rotenone showed that the toxicity was in the order 
of the rotenone content, but did not bear a direct relationship to it. 
It was stated that a derris sample containing 5-P GI "cent of rotenone and 
high total acetone extractives should prove as efficient for practical 
purposes as root^ of higher rotenone content. The rate of kill was 
slower when derris was applied as a dust than when used as either water 
suspension or extract. Tests were made against A. rumicis of a sample 
of derris root and a sample of cube root to compare the aphicidal proper- 
ties of these materials. The derris root selected contained 5 percent 
of rotenone and 17-9 percent of acetone extractives while the cube root 
contained 5 percent of rotenone and l6.7 percent of acetone extractives. 
The samples were compared as dusts, water suspensions, and acetone ex- 
tracts. On the whole the differences in toxicity to a-phids observed were 
too small to warrant a definite distinction between the two samples. 
Apparently derris and cube, provided they have the same rotenone and 
total-extractive content, are equally toxic to aphids. Roark (2J$U) in 
193S, in a review of the comparative value of derris and cube, referred 
to the work of these investigators. 
Lever ( 1S1 ) in 1935 published the results of tests of Derris tri - 
foliata from the British Solomon Islands. Specimens of roots, stems, 
and leaves were examined by the Rothamsted Experimental Station by spray- 
ing alcoholic extracts on A. rumicis. Results were as follows: 
Concentration of 
Derris species Sample alcoholic extractives Mortality 
Percent 
Percent 
0.U6 
Uo 
1.17 
60 
0.U6 
U 5 
1.5s 
71 
1.37 
S5 
0.07 
62 
D. trifoliata Roots from Savo: U 
Do. - - - - Stems from Savo: 3 
Do. - - ,- - Roots from G-izo: U 
Do. - - - - Stems from Savo: 6 
Do. - - - - Leaves from Savo : 7 
D. elli^-tica ' Roots from Malaya: 7 
Martin (192) in 193& reported finding about O.U percent of rotenone 
in a specimen of Tephrosia macropoda Harv. from the Hiatal Herbarium, De- 
partment of Agriculture, Durban. Qualitative insecticide tests using 
a cold alcoholic extract of the finely ground root diluted with saponin 
solution were made on A. rumicis. At concentrations e equivalent to 0.25 
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