RECENT PROGRESS IN ECONOMIC ENTOMOLOGY. 13 



ENTOMOLOGY. 



RECENT PROGRESS IN ECONOMIC ENTOMOLOGY, i 



PROFESSOR C. V. RILEY. 



The paper set forth the part which insects play in the economy of nature and 

 particularly their influence on American Agriculture. The earlier writers on 

 applied entomology in the United States, as Peck, Harris, Fitch, Walsh, Le- 

 Baron, and Glover, did some excellent work in their studies of the habits and 

 life-histories of injurious species, but the most important results followed when 

 such studies were combined with field work and experiment by competent per- 

 sons and upon scientific principles. A number of the remedies proposed in the 

 agricultural press are foolish and based on misleading empiricism. Economic 

 entomology as a science is of comparatively recent date. It implies full knowl- 

 edge of the particular injurious species to be dealt with and of its enemies; of its 

 relations to other animals and to wild and cultivated plants. In short, its whole 

 environment must be considered, especially from the standpoint of the farmers' 

 wants. The habits of birds, more particularly, and the bearings of meteorology 

 and of the development of minute parasitic organisms, must be considered. Ex- 

 periments with insecticides and appliances will then be intelligent, and success- 

 ful in proportion as the facts of chemistry, dynamics and mechanics are utilized. 



The complicated nature of the problem was illustrated by the life-history of 

 Phylloxera vastatrix, Planchon, and the difficulties often encountered in acquiring 

 the facts were illustrated by the late work on Aletia xylina, (Say). 



The chief insecticides considered for general use and applicable above ground 

 were tobacco, white hellebore, soap, arsenical compounds, petroleum and pyre- 

 thrum ; those for use under ground, naphthaline, sulpho-carbonates of potassium 

 and bisulphide of carbon. The most advantageous and improved methods of 

 utilizing each were indicated. Recent experiment showed that kerosene emulsions, 

 such as had been recommended lately in the author's official reports, were supe- 

 rior to bisulphide of carbon, when used under ground against the grape Phylloxera, 

 and the discovery is deemed of great importance, especially to the French people, 

 and those on the Pacific slope. Contrary to general belief, Pyrethrum powder 

 was shown to have a peculiar and toxic effect on higher animals as well as on 

 the lower forms of life. Its deadly influence on lower organisms led the author 

 to strongly recommend its use as a disinfectant and to express the belief that it 

 would yet come to be used in medicine. Dr. Hagen's recommendation of the use 

 of yeast ferment was touched upon. It had proved of little or no practical avail 



1. Abstract of a paper read before the Philosophical Society, "Washington, D. C, at its meet- 

 ing February 2, 1884. 



