-li- 
the seeds and leaves of Tephrosia vogelii were a"bout as toxic as nicotine, 
the test insect presumably being the "bean aphid. 
Tattersfield (256, 257 ) in 1925 reported that extracts prepared 
from "black and vrhite haiari ( Loncho carpus spp.) with water and organic 
solvents (particularly the latter) had "been found highly poisonous to 
aphids [-presumably A. rumicis ] as contact insecticides. In 1927 he re- 
ported that the roots and stems of "both black and white haiari were toxic 
to A. rumicis but that the leaves were not. Tubatoxin (rotenone) from 
Derris elliptic? , at a concentration of 0.25 percent, was almost com- 
pletely toxic to bean aphids. Six species of Tephrosia vrere also tested 
against bean aphids, with the following results: 
Snecies 
Parts tested 
Result 
T. vogelii ------ Leaves 
Do. -------- Seeds 
Do. -------- Stems 
Do. -------- Roots 
T. toxicaria ----- Do 
Do. -------- Stems 
Do. -------- Leaves 
T. macropoda ----- Roots 
Do. -------- Stems 
T. Candida ------ 
T. hookeriana - - - - 
T. purpurea ----- 
Toxic 
Do. 
Less toxic than leaves and seeds 
Do. 
Toxic • 
Do. 
Not toxic 
Toxic N 
Do. 
Low toxicity 
Do. 
Do. 
Tattersfield, Gimingham, and Morris (2_6l, 262 ) in 1925 reported 
that both alcoholic and aqueous extracts of Tephrosia vogelii Hook, were 
found to have high toxicity to A. rumicis as contact poisons. The toxic 
effect of the concentrated extracts on this insect was about the same as 
that of nicotine. Aqueous extracts of the leaves and seed proved very 
toxic when a suitable wetting reagent was used with them and were prefer- 
able to those made with organic solvents; the latter on drying tended to 
become somewhat insoluble, and the aqueous extracts had about the same 
toxicity. The aoueous and alcoholic extracts of a given weight of seed 
also had an eoual toxicity, but the dried extracts prepared by means of 
organic solvents were more readily worked up into an emulsion. The stems 
were less poisonous than either leaves or seeds. The same authors in 
1926 reported that alcoholic extracts of the roots and stems of white 
haiari and the stem? of black haiari (both species of Loncho carpus from 
British Guiana) possess notable insecticidal properties ^ r hen tested on 
the bean aphid. Crystals isolated from these plants were identical with 
tubatoxin (= rotenone) from Derris elliptica . Rotenone at a concentra- 
tion of 2.5 to 0.075 gm. per liter killed all aphids; 0.01 gm. per liter 
caused 20 percent to be moribund. Rotenone proved to be several times 
more toxic than nicotine. The alcoholic extracts of the roots of Tephro - 
sia toxicaria and the leaves of T. vogelii also possess notablr insecti- 
cidal properties when tested on A. rumicis . The roots and stems of T. 
Candida are less toxic. The most toxic substances isolated from T. 
