24 BULLETIN L201, U. S. DEPARTMENT OF AGRICULTURE. 
The powder from the moth mullein (Verbascum blattaria), used as 
a dust, had. a slight effect on roaches and tent caterpillars; used 
stomach poison, it had a very slight effect on grasshoppers and 
flies, hut Done at all on roaches, silkworms, and webworms. The 
water extract had no effect on webworms, potato-beetle larva?, and 
rose aphids, but a slight effect on bees and silkworms. An alcoholic 
extract was fatal to bees. 
The powders from the roots, stems, and leaves of zygademis 
(Zygadenus venenosus) and hot-water extracts from these powders, 
had no effect on grasshoppers, webworms, and potato-beetle larva?, 
ami only a slight effect on silkworms. 
CATALOGUE OF PLANTS TESTED FOR OR REPORTED TO 
POSSESS INSECTICIDAL PROPERTIES. 
In 1919 Roark (75) catalogued and published the names of nearly 
200 species of plants which had been tested for or reported to possess 
insecticidal properties. The present writers have been collecting the 
Literature on this subject since 1915, but certainly would have over- 
looked some of the references had it not been for Roark's publica- 
tion, which is not available for the average agricultural reader. 
The writers have veriiied, revised, and enlarged Roark's catalogue, 
and now it includes in all 267 species of plants, although 7 of these 
may be synonyms. The purpose of this catalogue is to serve as a 
handy reference and to encourage research along this line of work. 
Relative to the 1 jest-known plant insecticides, only a few references 
are given, but in regard to the little-known ones all the references 
that could be found are included. To avoid duplications concerning 
the plants tested by the writers, the reader is merely referred to the 
pages on which the writer's results are given, and to facilitate finding 
all the information about any given species given in this bulletin, 
the reader is referred to the "Index of the botanical and common 
names of plants catalogued " on pages 59-61. 
Achillea millefolium L. Astebaceae. Common yarrow. Europe, Asia, North 
America. 
The writers' results are given on page 21. 
Achillea nobilis L. Camphor yarrow. Europe. 
Grieseler (%6) reports that the flower heads have an action on 
insects similar to that of insect powder. 
Aconitum columbianum Nutt. Ranunculaceae. Columbia monkshood. 
Western North America. 
The writers' results arc given on page 21. 
Aconitum napellus L. Aconite. Old World. 
Gomilevsky (28) determined that a few drops of a strong water 
extract, dropped upon the body of a stag beetle (Lucarvm cervm), 
wore fatal. 
Aeschrion excelsa (Swartz) Kuntze. Simabtjbaceae. Synonyms: Picrasma 
exceUa Planch., Simaruba excelsa DC, Quassia exceUa Swart/.. Picraena c.r- 
a is, i Lindl. Jamaica quassia. West In<li<'s. 
The use of (jiiassia wood as an insecticide is well known. See the 
paper byline writers ((JO). 
