TREE INSECTS AND THEIR CONTROL 213 
openings that the caterpillars, when 
hatched, enter the wood to begin their 
work. Wounds and scars are a constant 
invitation to this insect, and its preference 
for such injuries is a strong argument for 
protecting trees from injury and the care¬ 
ful dressing and treatment of wounds. 
The insect lives for about three years, and 
spends almost the entire time eating into 
and feeding on the heart-wood. The 
burrow may be half an inch in width, and 
will cause the wilting of twigs and unsat¬ 
isfactory growth. 
Egg-laying occurs early in the summer, 
and, soon after hatching, the caterpillar 
burrows into the heart-wood. When the 
insect emerges, after three years of dam¬ 
age, it is in the form of the adult moth. 
occur and that such injuries as may come 
are carefully and promptly cleaned and 
dressed with tar or paint. (Page 145). 
When a tree becomes infested, winter is 
the time for destroying the worm. Dur¬ 
ing that season all infested wood should be 
cut away and burned. Into the wounds 
caused by the cutting and the tunneling, 
carbon disulphid should be injected as 
an added measure of control, and the 
wounds should immediately be plugged 
and sealed with soap, grafting-wax, clay 
or putty. 
Maple and Oak Twig Pruner 
Habits This enemy specializes on 
and the Maple and the Oak, and 
Damage, while it does not kill the trees 
it impairs their looks by sever¬ 
ing twigs and causing them to fall to the 
ground or hang to branches. The grub 
passes the winter in the severed twig, 
emerging in June as a pupa or chrysalis. 
In July the parent beetle lays its eggs on 
small twigs and, upon hatching, the grubs 
begin at once to feed on the wood, making 
tunnels which sever the twigs. During 
the summer the ground is covered with 
twigs cleanly cut off, as with a saw. In 
the center of each twig is a burrow, filled 
with debris, and in this burrow will usu¬ 
ally be found a white grub with brown 
jaws. Many twigs almost severed will be 
seen hanging from the tree. Damage to 
the shape of the tree is the most serious 
result. 
Remedies. Since the insects remain 
in the severed ends, the best 
remedy is to gather and burn the fallen 
and hanging twigs. This should be done 
before June, the time for the adult beetles 
to leave the twigs in which the winter has 
been spent. Action at this time will pre¬ 
vent the laying of eggs for the production 
of a new brood. 
SAP-SUCKING INSECTS 
Oyster-shell Scale 
(See description and remedies under Elm) 
Cottony Maple Scale 
Habits Considerable damage some- 
and times results from the attack 
Damage, of this insect. The presence 
of the scale is first noticeable 
in June, when the body of the adult female 
Remedies. It is not always necessary 
to apply remedies, but if 
needed, a spraying with dilute kerosene 
emulsion, summer strength, is effectual if 
used during the hatching season. Brush- 
