JOURNAL 
OF 
ECONOMIC ENTOMOLOGY 
I 
OFFICIAL ORGAN AMERICAN ASSOCIATION OF ECONOMIC ENTOMOLOGIST 
Vol. 17 JUNE, 1924 No. 3 
SOIL INSECTICIDE INVESTIGATIONS AT THE JAPANESE 
BEETLE LABORATORY DURING 1923 
By B. R. Leach, W. E. Fleming and J. P. Johnson 1 
Abstract 
The experimental work thruout the year with Popillia japonica has been carried 
on with the object of evolving methods of chemically treating the soil about the 
roots of such plants as conifers, boxwoods, azaleas, rhododendrons, hydrangeas, ferns, 
blueberries and perennials for the control of the soil stages of the Japanese beetle. 
Emulsions of carbon disulfide and wormseed oil have proved satisfactory in these 
connections and are now in use by the local nursery and greenhouse concerns. 
The Japanese beetle is now gradually spreading over an area in 
New Jersey and Pennsylvania within which is centered a large propor¬ 
tion of the nation’s nursery interests. Since the insect inhabits the soil 
throughout the greater part of its life and is found about the roots of 
plants almost anywhere within this area, a quarantine has been es¬ 
tablished prohibiting the shipment of soil, or plants with soil about their 
roots to points outside unless freed of possible infestation. Under these 
circumstances the experimental work during the past four years has 
been carried on along fundamental lines with the object of devising 
various methods of soil treatments which would cover the treatment of 
different types of nursery stock grown within the area. In addition to 
the above problems, an important side line has been the study of con¬ 
trolling the larvae in specialized areas of turf, such as lawns and golf 
greens. 
During these four years the writers have tested practically every 
chemical which offered possible merit as a soil-insecticide. Included in 
this broad survey of the chemical field is a two-year study of organic 
compounds made for the specific purpose of finding new soil insecticides. 
The work, which will be published in the near future, indicates that no 
Contribution from the Japanese Beetle Laboratory, Bureau of Entomology 
U. S. D. A. in cooperation with the Departments of Agriculture of the States of 
New Jersey and Pennsylvania. 
361 
