JOIMAL OF AGEDLTiAL RESEARCH 



DEPARTMENT OF AGRICULTURE 



Vol. XVII Washington, D. C, August 15, 191 9 No. 5 



DERRIS AS AN INSECTICIDE 



By N. H. McIndoo, Insect Physiologist, Deciduous Fruit Insect Investigations, Bureau 

 of Entomology, A. F. SiEVERS, Chemical Biologist, Drug-Plant and Poisonous- 

 Plant Investigations, Bureau of Plant Industry, and W. S. Abbott,' Scientific 

 Assistant, Bureau of Entomology, United States Department of Agriculture 



INTRODUCTION 



The investigation of the possibilities of Derris as an insecticide is a con- 

 tinuation of the cooperative work inaugurated by the Bureaus of Ento- 

 mology and Plant Industry, and the most important results pertaining to 

 the study of Derris are discussed in this paper. There are now on the 

 market several standard insecticides : Arsenicals, used as stomach poisons • 

 nicotine solution, used as a contact insecticide; pyrethrura powder, em- 

 ployed as a dusting powder; and soaps, lime sulphur, oil sprays, etc. Not 

 one of these acts both as a stomach poison and a contact insecticide. The 

 following pages will show how well Derris acts in both of these ways. 



In a search through the vegetable kingdom for plants possessing toxic 

 principles with a view toward utilizing them as insecticide material, 

 attention was directed to the large class of plants which are used exten- 

 sively in the tropics as fish poisons. There are many hundreds of these 

 plants, included in several families, and their habitat extends over prac- 

 tically the entire Tropics. That many of them belonging to particular 

 families and genera display a remarkably toxicity to fish has long been 

 known, and probably for ages the natives of the Tropics have used some 

 of these plants as a means of catching fish. 



While a plant toxic to fish need not necessarily be poisonous to in- 

 sects, nevertheless, some of the fish poisons have already been recom- 

 mended and used in the Orient as insecticides. If the fish poisons prove 

 to be efficient insecticides, their practical utilization is at once suggested, 

 because many of them are known to be very abundant in the Tropics. 

 The present investigation deals with six or seven species, all belonging 

 to the same genus, which is widely known as Derris.^ Of these species 

 only Derris elliptica Benth. seems to have been used widely as a means 

 for catching fish; it is regarded as a powerful fish poison. 



* A portion of the experimental part of this investigation was performed at the Insecticide Board's testing 

 laboratory, located at Vienna, Va., by W. S. Abbott and E. W. Scott, Entomologist, Enforcement Insec- 

 ticide Act, under the direction of the latter. 



2 Although this genus has commonly been known as Derris, the rules of botanical priority require the 

 use of the name Dcguelia of Aublet. Of the six species mentioned, the following have received names 

 under DegueUa: Deguelia elliptica (Wall.) Taub. [Derris elliplica (Wall.) Benth ]; Deguelia robusta (Roxb.) 

 Taub. [Derris robusta (Roxb.) Benth.]; £)e(7Me//a iimorensis (DC.) Taub. [Derris scandens (Roxb.) Benth.] 

 Degtielia uliginosa (DC.) Baill.; [Oerri. tiligmosa (DC.) Benth.]. S. F. BlakE. 



Journal of Agricultural Research. Vol. XVII, No. s 



Washington, D. C. Aug. 15, 1919 



sb 177 KeyNo.K-76 



