April, ’20] 
DAVIS: GREEN JAPANESE BEETLE 
185 
THE GREEN JAPANESE BEETLE PROBLEM 
By John J. Davis, Riverton , N. J. 
It is intended at this time to give a concise resume of the green 
Japanese beetle problem, including its present status, plans for future 
work and information which is of special interest to you whose duty 
it is to protect your state from the introduction of dangerous insect 
pests. 
The green Japanese beetle (Popillia japonica Newm.), a native of 
Japan, was introduced into the LTnited States at Burlington County, 
New Jersey, prior to 1916, probably five or six years ago, and pre¬ 
sumably in the grub stage in soil about the roots of perennial plants. 
• • 
It was first discovered by Messrs. Harry B. Weiss and Edgar L. 
Dickerson about the middle of August, 1916, in a nursery, probably 
near the original point of introduction, 1 near Riverton, New Jersey. 
The rate of increase has been remarkable. When discovered in 
1916 only about a dozen beetles were found, according to Mr. Weiss, 
and these only after a search, while now (1919) in the same locality 
and at the same season one person can collect by hand 15,000 to 20,000 
beetles in a day and in favorite places the grubs are as frequent as 250 
to the square yard. The area of known infestation has increased from 
approximately 600 acres in 1917 to 15,000 acres in 1919 and according 
to the most conservative estimates by those familiar with the activities 
of the insect a year ago, the beetles were at least ten times more abun¬ 
dant numerically in 1919 than the previous year. 
The Bureau of Entomology inaugurated a study of this insect in 
the late summer of 1917, Mr. Wm. O. Ellis being assigned to the study 
of its life history and habits. Mr. Ellis continued his connection with 
the project until the summer of 1919 and most of the data on the life 
history are the result of his investigations. In the spring of 1918 it 
was planned to take active steps to control and, if possible, eradicate 
the insect, the New Jersey State Department of Agriculture cooperat¬ 
ing substantially. Mr. W. H. Goodwin was assigned the task of 
control, he and Mr. Ellis working jointly on the problem in their 
respective fields, the whole project being supported by an advisory 
board, consisting of Doctors A. L. Quaintance and Thos. J. Headlee. 
Mr. Goodwin continued his service in charge of control operations until 
the fall of 1919. The writer was assigned to this project May 1, 1919, 
and has had in charge of the different divisions Messrs. Goodwin for 
control operations, Ellis, the life history, and C. H. Hadley, the quar- 
1 It is a matter of historical interest that this insect was first found within about 
one-quarter mile of the place where the San Jose scale was first discovered in the 
eastern United States. 
