February, ’24] smith: Japanese beetle 107 
INSECTICIDAL PROPERTIES OF SOME SULFUR COMPOUNDS 
By Albert Hartzell and F. H. Lathrop, Geneva , N. Y. 
(Withdrawn for publication elsewhere) 
President A. G. Ruggles: We will now listen to a paper by L. B. 
Smith. 
THE JAPANESE BEETLE STATUS IN 1923 
By Loren B. Smith, Entomologist, U. S. Department of Agriculture 
Abstract 
In the season of 1923 the Japanese beetle, Popillia japonica Newm., increased the 
area of its distribution from 770 square miles to approximately 2500 square miles. 
Owing to the increase in area and cost of inspection of farm produce at point of 
origin, a zone was established to include a large portion of the territory in which 
locally grown produce was consumed. All produce shipped to points outside the 
zone was inspected at the point of origin and was then shipped direct to its desti¬ 
nation. 
During the past season growers in the heavily infested territory, who applied 
sprays according to directions given by the Japanese beetle laboratory, obtained 
excellent protection of the foliage and fruit on appies, grapes and cherries, also of the 
foliage of shade trees and ornamental shrubs. 
Measures of control have been developed whereby the larvae may be destroyed in 
golf courses and lawns as well as where they occur in the soil about the roots of 
various plants. 
In addition various parasitic enemies of the Japanese beetle are being imported 
in large numbers in order to supplement the various natural agencies which tend to 
reduce the numbers of the beetle and to serve as a check on the continued increase 
in concentration of the beetles in the areas which have been longest infested. 
Eight years have elapsed since the Japanese beetle (.Popillia japonica 
Newm.) was first found in this country. From the point of original 
infestation the insect has increased in numbers and spread outward in 
all directions until, at the close of the summer of 1923, it covers an area 
of more than 2500 square miles. The species has not only been spread¬ 
ing from the locality where it was found in 1916 but the infestation has 
increased in density in the territory near Riverton, N. J., where the 
beetles have been present for the longest time. The number of grubs 
found in the soil during the Autumn months offers a fairly reliable index 
of the degree of infestation. In 1921 the largest number of grubs of 
Popillia found in a measured square yard of soil was 311. In 1922 as 
many as 1031 larvae were found in one square yard of turf on a golf 
course. During the season just past several diggings were made in 
which over 1200 larvae were found; the highest number being 1531 
