8 THE IMPORTED ELM LEAF-BEETLE. 
The beetle assists the larva in its destructive work, but, as ustial in 
such cases, the damage done by the perfect insect is small when com- 
pared with that done by the larva. There are three or four annual 
generations of the insect, according to the character of the season. In 
the month of September the beetles prepare for hibernation, seeking 
shelter in hollow trees, in the ground, under old leaves, &c., and remain 
dormant until the following spring. 
REMEDIES. 
M. Girard says: 
There is no other means of destruction than to jar the branches over cloths to col- 
lect the larve and adults which fall. It is also possible when they are on the ground 
to distribute on them boiling water orsteam, or even quicklime or solution of sulpho- 
carbonate of potassium. 
In our own country much more has been accomplished toward prac- 
tically combating this insect. 
In the U. S. Agricultural Report of 1867, Glover suggested the use of 
oil and tar gutters and other barriers surrounding the base or the body 
of the tree, devices similar to those used against the Canker Worm and 
Codling Moth. He then and afterward (1870) recommended “ to place 
around each tree small, tight, square boxes or frames, a foot or 18 inches 
in height, sunk in the earth; the ground within the inclosure to be cov- 
ered with cement, and the top edge of each frame to be covered with 
proad, projecting pieces of tin like the eaves of a house or the letter T, 
or painted with some adhesive or repellant substance, as tar, &c. The 
larvee descending the tree, being unable to climb over the inclosure, 
would change into helpless pupze within the box, where they could daily 
be destroyed by thousands. Those hiding within the crevices of the 
bark of the trunk could easily be syringed from their hiding places.” 
(U.S. Agricultural Report, 1870, pp. 73, 74.) These boxes were carefully 
tested at this Department, and they worked as described. While coal- 
tar and other adhesives were recommended, we have found scalding-hot 
water most convenient for destroying the insects that accumulate in the 
inclosure or upon the ground elsewhere. Where branches are low and 
droop near the ground some of the larve descend the wrong way and fall 
off, but shade trees should not be allowed to grow in this low, drooping 
manner, and under all ordinary circumstances, where the branches are 
not severely jarred to encourage the insects to drop, the larve will de- 
scend by the trunk and become captured in the devices here noticed. 
Mr. Glover regarded the pupa state as the most favorable in which 
to kill the insect, as 1t can then be easily crushed or scalded. Concern- 
ing the tobacco treatment, he adds that “‘syringing the trees with strong 
tobacco water has been tried with some good effect, but the larye not 
touched by the fluid are merely knocked down by the concussion, and, — 
if nearly ready to change into pupe, effect their transformation where 
they fall.” 
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