TREES AS GOOD CITIZENS 
9.06 
in the bark. The damage to a tree shows 
itself first in leaves turning brown at the 
ends of infested branches, then by the 
death of branches and finally in the death 
of the tree. In dying trees, the bark on 
trunk and larger branches may be easily 
peeled off in patches, and underneath 
these the grubs are found. 
Leopard 
Habits This moth takes its name 
and from the leopard-like spots on 
Damage, its white wings. The adult 
moth lays eggs in crevices of 
the rough bark, a single specimen some¬ 
times depositing 700 or 800 eggs. The 
larvae, or grubs, hatch within 10 days and 
at once begin their destructive work of 
feeding on the wood, boring toward the 
heart of the tree as they feed. Twigs 
infested break off, the bark splits and 
forms ugly scars, and chips and matted 
discharges are found at the entrance to 
the burrow. The grubs’ period of activity 
continues for two years, serious damage 
is caused and frequently the death of the 
tree results from girdling of the trunk. In 
about two years the grub changes into a 
chrysalis and then into a moth, and egg- 
laying follows. Even when the attack is 
not so severe as to cause death, the 
growth of a tree is seriously hampered. 
Because of this borer’s tendency to 
cooperative work is always necessary. 
Twig 
Habits The pet habit of this insect 
and is to destroy twigs and bran- 
Damage. ches by girdling them until 
they fall off, or die and remain 
hanging. The girdler appears in late 
summer or early fall and is apt to feed 
on the thin bark of twigs before laying 
eggs. The female attacks twigs from % 
to 1^ inches in diameter, and cuts rings 
around them deep into the wood; the eggs 
are laid in openings cut through the bark. 
It is these wounds that cause the twig to 
die. After the eggs are hatched the grubs 
feed on the wood for a year or more. 
Examination of the burrow in a fallen 
Moth 
Treatment. The control of this insect 
is difficult. When a tree or 
limb has become badly infested before 
discovery of the attack, the only recourse 
is to cut and burn the infested part 
immediately, even if this involves cutting 
down the tree itself. This drastic action 
is necessary to prevent the spread of the 
pest to other trees. In cutting and burn¬ 
ing, care should be exercised, and prompt 
action employed, to keep the borers from 
escaping and migrating. 
If a tree shows a few burrows, it is some¬ 
times possible to arrest the damage by 
injecting carbon disulphid into the chan¬ 
nels. This kills the borers. In some cases 
the borers may be killed bodily by prob¬ 
ing with a flexible wire inserted into the 
channel. Action should always be immedi¬ 
ate when the borer’s presence is detected. 
migrate from tree to tree, community or 
Girdler 
Treatment. There is no remedy for 
this insect pest, but it con¬ 
tributes to its own destruction by remain¬ 
ing in the falling or broken twig. It is 
important to gather and burn the twigs 
as soon as they fall or break, for the pur¬ 
pose of destroying the girdlers. This is 
the only treatment to be given. Nature 
helps in destroying the pest by letting 
them overcrowd each other in the individ¬ 
ual twig. 
