10 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
246TH MEETING. FEBRUARY 2, 1884, 
The President in the Chair. 
Forty-eight members and guests present. 
The Chair announced the election to membership of Mr, Taomas 
ROBINSON. 
Mr. C. V. Ritry made a communication on 
RECENT ADVANCES IN ECONOMIC ENTOMOLOGY. 
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, LeBaron, 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 persons 
and upon scientific principles. A number of the remedies proposed 
in the agricultural press are foolish and based on misleading em- 
piricism. Economic entomology as a science is of comparatively 
recent date. It implies full knowledge 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, the whole 
environment of the species must be considered, especially from the 
standpoint of the farmer’s wants. The habits of birds, more par- 
ticularly, and the bearings of meteorology and of the develop- 
ment of minute parasitic organisms must be considered. Experi- 
ments with insecticides and appliances will then be intelligent 
and successful 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 vastatriz 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 com- 
pounds, petroleum, and pyrethrum; those for use under ground, 
naphthaline, sulpho-carbonate of potassium, and bisulphide of car- 
