-2- • 
677 genera, and 159 families. Most of these species do not deserve 
further investigation, and some of the families, for example Asteraceae, 
have been extensively investigated. In each of these two divisions 
the plants are grouped by families so that the families may be com- 
pered from an inseoticidal standpoint. 
The botanioal names are listed in accordance with the International 
Rules of Botanical Nomenclature, and have been reviewed by botanists—/ 
in the Bureau of Plant Industry, Soils, and Agricultural Engineering, 
the Bureau of Agricultural and Industrial Chemistry, and the National 
Herbarium. 
The references were obtained mostly from the files of the Division 
of Insecticide Investigations and the Division of Control Investigations, 
and from the Review of Applied Entomology. Most of the notes were 
taken from the original articles, although occasionally the author had 
access only to abstracts. 
BRIEF HISTORY OF INSECTICIDAL PLANTS 
Dioscorides (A* D. 40-90), according to Blyth and Blyth ( 64 , pp. 
4-5), divided poisons into three classes — animal, plant, and mineral. 
As plant poisons he enumerated opium, black and white Hyoscyamus , 
Mandr agora , Conium , elaterin, and the juioes of Euphorbia species. He 
also especially mentioned aconite, the deadly nature of which the 
Greeks were well aware* Colchicura was also known to Dioscorides. 
Veratrum album and V. nigrum were famous medicines of the Romans, and 
constituents of their "rat and mioe powders •" They were also used as 
insecticides. 
From the time of the early Romans to the twentieth century only 
three efficient insecticides were discovered— nicotine, pyrethrum, and 
hellebore. The nicotine-insecticide industry has been developed largely 
in America, whereas the pyrethrum and hellebore industries are European 
in origin. During the nineteenth oentury there was little interest in 
searching for new insecticidal plants, although in 1885 the United 
States Department of Agriculture (Riley, 325 ) tested 42 species of 
plants a-ainst cotton caterpillars without finding, any new effective 
ones. In the second decade of the present century large-scale in- 
vestigations were be^un which led to a new world-wide industry using 
Derris and Loncho carpus as insecticide materials. More recently 
1/ S. F. Blake, C. 0. Erlanson, P« R. Fosberr, Oliver !.!. Freeman, 
F. J. Hermann, E. C. Leonard, Robert F. Martin, Rogers McVaugh, 
C. M. Muller, Paul G. Russell, J. A. Stevenson, and Jason R. Swallen. 
