212 
TREES AS GOOD CITIZENS 
BORING INSECTS 
Sugar Maple Borer 
Habits This is the worst insect 
and enemy of the Sugar Maple. 
Damage. It differs from other borers in 
that its attack is made against 
trees which have not been weakened. As 
a result of its work large limbs and even 
entire trees may be killed. The parent 
insect appears between June and August, 
emerging from oval holes in the bark. At 
this stage it is a thick, black beetle, about 
one inch long, with short horns, and 
marked with brilliant yellow. Egg-laying 
occurs during July or August, causing 
discoloration of the bark upon the trunk 
and larger branches. The larvae begin 
boring soon after hatching, and their 
work causes a flow of sap and throws out 
a substance which often forms a small 
mass on the surface at the point of 
entrance. The first winter is spent on the 
sapwood and in the following spring the 
borer tunnels between bark and sapwood 
or into the outer 6apwood. The burrows 
during the second summer are half an inch 
or more in width and almost as deep, 
and they form serious wounds. If these 
tunnels girdle a tree or limb they cause 
death. 
The presence of the borer may be 
detected by various signs, including dead 
limbs, dead areas of bark, ridges or eleva¬ 
tions just under the bark, naked scars on 
limbs or trunk, especially near the base of 
a large limb, oval holes about half an inch 
wide and a substance resembling sawdust 
at the base of the tree or in bark crevices. 
Sometimes the leaves on a limb will sud¬ 
denly dry up and die, and a flow of sap 
and “sawdust” will be found somewhere 
on the limb. 
Remedies. Careful examination of 
trees for signs of the presence 
of borers should be made every spring and 
fall. If discoloration of the bark and 
exuding sap indicate that eggs have been 
laid, or if sawdust or excrement have 
exuded, prompt action for control should 
follow. The first step is to cut away the 
bark and follow the burrow till the grub is 
located and destroyed. The cutting must 
be done with great care, with clean sur¬ 
faces, and the wounds covered with creo¬ 
sote-tar mixture or two coats of good 
white lead paint. Sometimes the grub 
may be reached, and killed by probing 
with a flexible wire to the end of the 
burrow. Carbon disulphid injected into 
the holes will kill the borers if all openings 
are promptly plugged with wax, soap, 
clay or putty to shut out air, but when 
this method is used it is not possible to 
know that the borer has been killed. 
Spraying the tree in late summer with 
poisoned kerosene emulsion or miscible 
oil is effective in killing borers which have 
just penetrated the bark. The spray 
should be confined to the trunk and the 
larger branches and care must be taken 
that none of it reaches the foliage, as the 
leaves are seriously injured by these 
solutions. 
Trees which are badly infested, or dying 
trees or branches, should be cut down and 
burned. This should be done during the 
winter and spring, to prevent any of the 
adult beetles from emerging and causing 
damage to other trees. 
Leopard Moth 
(See description and remedies under Elm) 
Habits While seldom causing the 
and death of a tree, this worm is 
Damage, responsible for serious deform¬ 
ities which result in unsightly 
appearance. Its eggs are laid near 
wounds or scars and it is through such 
The most effectual treat¬ 
ment of this insect is to take 
steps to prevent a tree from 
becoming infested. Since 
wounds and scars invite the laying of eggs, 
it is important to see that no wounds 
Carpenter Worm 
Prevention 
and 
Remedies. 
