140 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
effectiveness of spray because, if the beetles feed upon the foliage, 
which has been sprayed with four pounds of powdered arsenate of 
lead to fifty gallons of water, 60 % to 70% die. 
Furthermore, the data indicate that natural enemies are already 
beginning to make a reduction in numbers. It is true that this re¬ 
duction, which is only about 2% does not, in any way equal the per¬ 
centage of increase, but it may be taken, I think, as a straw indicating 
the way in which the wind is beginning to blow. 
Crops that are constantly cultivated throughout the beetle season, 
do not show during the fall or the following spring any considerable 
number of grubs in the soil. Plowing or disking the soil to a mini¬ 
mum depth of four inches just after the frost makes its first appear¬ 
ance in the ground seems practically to clean up Japanese beetle 
grubs. 
Natural enemies from Japan are being introduced into the infested 
district. It is planned to examine Korea, Northern China and North¬ 
ern India for additional, probably effective species. 
A quarantine designed to prevent the insect from being distrib¬ 
uted on the “long jump” is being vigorously and apparently effect¬ 
ively enforced. This quarantine has both state and inter-state 
features and it is enforced by the laboratory organization, working 
under the immediate direction of Mr. C. W. Stockwell, who has 
charge of the quarantine division of the Japanese Beetle Laboratory. 
To show you the severity with which this quarantine is being ad¬ 
ministered I have only to point out that a nursery of considerable 
size, located within the infested district and devoting the majority 
of its energy to the production of evergreen shrubs and trees is com¬ 
pletely unable to do business in plants of this kind outside the quaran¬ 
tine area. The enforcement of this quarantine offers hard conditions 
to a nursery of this sort but the safety of the rest of the country at 
large demands that this procedure be carried out, until some practical 
method of cleaning the earth ball has been discovered. As the normal 
spread of the insect goes on, more nurseries of this sort will be found 
to be included within the infested district, and the interference with 
the normal business carried on by those concerns will be very large 
and the losses entailed will, I believe, be very considerable. 
Appropriations for the adequate carrying out of this work against 
the Japanese beetle have in the past been forthcoming and larger 
ones seem in immediate prospect, not only from the United States 
■> government but from the states of New Jersey and Pennsylvania. 
