24 BULLETIN 1201, U. S. DEPARTMENT OF AGRICULTURE. 



The powder from the moth mullein ( V 'erbascwm blattaria) , used as 

 a dust, had a slight effect on roaches and tent caterpillars; used 

 as a stomach poison, it had a very slight effect on grasshoppers and 

 flies, but none at all on roaches, silkworms, and webworms. The 

 water extract had no effect on webworms, potato-beetle larvae, 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 zygadenus 

 (Zygadenus venenosus) and hot- water extracts from these powders, 

 had no effect on grasshoppers, webworms, and potato-beetle larva?, 

 and only a slight effect on silkworms. 



CATALOGUE OF PLANTS TESTED FOR OR REPORTED TO 

 POSSESS INSECTICIDAL PROPERTIES. 



In 1919 Eoark (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 verified, 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 best-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. Asteraceae. Common yarrow. Europe, Asia, North 

 America. 



The writers' results are given on page 21. 

 Achillea nobilis L. Camphor yarrow. Europe. 



Gieseler (26) reports that the flower heads have an action on 

 insects similar to that of insect powder. 



Aconitum columbianum Nutt. Ranttnctjlaceae. Columbia monkshood. 



Western North America. 



The writers' results are given on page 21. 



Aconitum napellus L. Aconite. Old World. 



Gomilevsky (£8) determined that a few drops of a strong water 

 extract, dropped upon the body of a stag beetle (Lucanm cervus), 

 were fatal. 



Aeschrion excelsa (Swartz) Kuntze. Simarubaceae. Synonyms: Picrasma 

 excelsa Planch., Simaruba excelsa DC, Quassia excelsa Swartz, Picraena ex- 

 celsa Lindl. Jamaica quassia. West Indies. 



The use of quassia wood as an insecticide is well known. See the 

 paper by the writers (60). 



