-3- 
anabasine, derived from A n abasia aphylla , has become commercially im- 
portant in the country of its' origin, Russia, and Tephrosla is also 
used locally in a few places in Africa where it is easily obtained* 
In 1915 and 1916 the Russian investigators Gomilevsky (164), 
Goriainov ( 166 ) , and Sohreiber (358-56 0) wrote considerable about 
vegetable insecticides, but they tested only a comparatively few 
plants and discovered none of commercial value* For centuries a few 
countries, for example China, have had their own insecticides, but 
these have not become commercially important in other countries* 
In 1915 the United States Department of Agriculture began a 
series of investigations on this subject* The first problem was to 
find a substitute for nicotine, which was expensive, and in 1916 
Mclndoo (254 ) reported the results of his studies on nicotine as an 
insecticide* This was followed in 1917 by a paper on quassia (Mclndoo 
and Sievers, 258 ), and in 1919 by one on derris (Mclndoo, Siever6, and 
Abbott, 260 ) > Soon after the publication of the last paper an English 
firm, which had previously tried to sell its derris products in the 
United States, prepared other derris spray materials on the basis of 
information given by these writers. Since that time interest in derris 
has grown rapidly, and it is now used more widely than nicotine* 
A later problem w«>s to find a substitute for both nicotine and 
derris, one that could be grown cheaply in America* This was partly 
solved by the finding of cube in South America, as first reported by 
Mclndoo and Sievers (259 ) in 1924* Up to that time cube was practi- 
cally unknown, both botanically and from an insecticidal viewpoint* 
It has since been identified as a species of Lon oho carpus * These 
writers also gave the results of testing 232 preparations from 54 other 
species of plants against 28 species of insects, and reported on others 
mentioned in the literature, making a total of 260 different plants* 
In 1920 appeared a bulletin on insect powder (pyrethrum) by 
McDonnell, Roark, LaForge, and Keenan ( 251) » 
Work in England on vegetable insecticides was begun at the 
Rothamsted Experimental Station in 1920 (Tattersfield 390 , p. 90)* 
In 1923 Tattersfield and Roaoh ( 396 ) reported on the chemical prop- 
erties of derris, and Fryer, Stanton, Tattersfield, and Roach (147) 
on its inseoticidal properties* In 1925 appeared a paper by Tattersfield, 
Gimingham, and Morris ( 392 ) on the toxicity of Tephrosia , which grows 
in West Africa, the Sudan, Rhodesia, and the Comoro Islands* Following 
a search for some substance that would prove an adequate alternative 
to nicotine as a contact insecticide, they found that extracts of 
Tephrosia could be substituted for nicotine against aphids. In 1926 
the same writers (593) discussed 28 species of plants as contact 
