TREE INSECTS AND THEIR CONTROL 205 
caterpillar is more than an inch long, with 
red head, three black plumes, and four 
yellow, brush-like tufts on the back. 
Community action is essential to the destruction of the tussock moth. To treat 
one tree and neglect another will not protect even the tree which is given care, as the 
caterpillar travels from one tree to another. All trees should be treated at the same time. 
Large Elm Sawfly 
Habits This is an insect much like a 
and caterpillar, which eats leaves 
Damage, and girdles the bark of twigs, 
often causing a tree to have an 
appearance of having been damaged by 
fire. Another form of damage to the 
leaves is the appearance of blisters, caused 
by the habit of the female of making slits 
in the leaves and thrusting eggs into these 
pockets. The eggs hatch in early summer 
and produce yellowish-white worms, 
coiled and cylindrical, with white lines 
down the middle of their backs. These 
worms feed on the leaves for several weeks 
and then bury themselves in the ground at 
the base of the tree for the winter. Mat¬ 
ing and the deposit of eggs take place in 
the spring. 
BORING 
Remedies. If the presence of the saw- 
flies is detected during the fall 
or winter, they should be destroyed at 
once, by burning the debris or rubbish in 
which they may be hidden or by breaking 
up the ground at the base of the tree in 
which they may be buried, and crushing 
them. In the spring as many as possible 
should be picked from the foliage, or 
infested leaves taken off and destroyed. 
If spraying becomes necessary lead arsen¬ 
ate should be thoroughly applied. 
INSECTS 
Elm Borer 
Habits This boring insect does great 
and damage to the Elm, and is 
Damage, especially apt to attack a tree 
weakened by disease or from 
other cause. At times it becomes epi¬ 
demic and may destroy the trees of an 
entire community or neighborhood. The 
eggs are laid singly or in groups on the 
bark at any time between May and 
August, by a gray, long-horned beetle 
about one-half inch long and marked with 
red lines and black spots. The eggs 
hatch into very small grubs without feet, 
and these grubs immediately tunnel 
through the bark into the cambium layer. 
Here they continue their boring, excavat¬ 
ing wider cavities as they grow larger. 
When these cavities encircle a limb or 
trunk the effect is to girdle and kill. The 
grub is white and more than an inch long 
when grown. On reaching full growth it 
cuts out a cell under the bark and emer¬ 
ges in the spring as a beetle, making its 
exit through a round hole which it cuts 
Method There is no way to destroy 
of this borer except by total 
Combat, removal of such part of the tree 
as may be infested. If the 
attack of the beetles is discovered when 
the infested area is small and confined to 
the branches, it is possible to save the tree. 
On the other hand, if the trunk has been 
attacked there is nothing to do but cut the 
tree down. In removing branches or cut¬ 
ting down the tree it is essential that the 
wood be burned, as this is the only way 
to prevent the borers from migrating to 
other trees near at hand. 
Since the borer is most apt to attack a 
tree already weakened, one of the most 
efficient safeguards against attack is to 
provide each tree with proper nourish¬ 
ment and protect it from injuries of all 
kinds. 
