Middlebury register. (Middlebury, Vt.) 1886-1937, 1898-06-03
OUR FOREST PEST.
EXPERIMENT STATION BULLETIN ON
THE TENT CATERPILLAR.

J Apply to Kill the Pest.
This insect which was quite destructive
last year has again appeared at several
points and is reported as doing great
damage, particularly to the maple and
apple trees. A full description with
remedies was published some months
ago by the Vermont Experiment station
in Bulletin 60, from which the following
description is condensed:
The forest tent caterpillar may flourish
for some time In forests before it attracts
attention, and then may suddenly mi
CRATE to adjacent orchards, where it APP
pears very unexpectedly in large
swarms. This insect confines its ravages
mainly to the apple and sugar maple.
1t was widely distributed over the..state.
In most places it was quite destructive.
In some orchards the caterpillars are
said to have been so numerous as almost
to cover the trunks of the trees.
Description: The caterpillars when
first Matched are minute black worms,
usually creeping about in companies,
and when moving some distance doing so
in single file. In about two weeks they
are of yellowish brown color, and later
begin to take on colors of the mature
insect. The fully grown caterpillar is a
a somewhat hairy worm, about two
inches long. The body is blush above,
changing on the sides to greenish, while
underneath it is dark, the legs being
nearly or quite black. The whole body
is thickly sprinkled with black dots and
bears several light longitudinal lines.
A line of light spots along the back is
conspicuous. A wide yellow line and a
whitish band extend along each side.
Short, light, yellowish-brown hairs are
sparsely scattered over the body. On
each Joint, except the eleventh, there are
two black, shining tubercles from which
arise few black hairs. The caterpillars
become mature about the first week in
June. At this time they cease feeding
and do not, as before, collect in groups,
but wander singly over the tree, or some
times away from 1t in search of shelter
for the cocoon.
Food. 1t is a more general feeder
than is the common tent caterpillar and
feeds on all our common fruit trees, and
on naples, oaks, walnuts, populars, ash,
etc. In some places it prefers the apple
to any other tree, in others it chiefly
attacks the sugar maple. Again these
trees are largely neglected and the oak
is sought, elsewhere it is the poplars
that suffer most. In all cases there is
loss of needed foliage and correspond
ing injury done the tree.
Remedies. Often the best remedy
which can be used against injurious In
sects is prevention, and this is emphat-
ically so in the present case. Pre-
vention, however, is not always possible
and remedies must be used. After the
caterpillars have become established in a
grove or orchard 1t is not easy to dis.
lodge them. Now that the worms ase
nearly full grown and the nests conspic-
uous many may be destroyed by the
torch. A rag wound about the end of
pole, fastened by a bit of wire and
soaked with kerosene may be applied
both to the nests and clusters of worms.
1t may be necessary to go over the trees
a second time. If, as may very likely
occur, they gather in clusters on the
trunk they may be crushed and this
should be done promptly for the oppor-
tunity may not come again. The clus-
tiers are most commonly formed In early
morning or at dusk. A much less effic-
lent method, one which may be at the
time the best which can be followed is
that of vigorously Earring the branches
on which the worms are located. AS
they let themselves down by the thread
they spin, they can be gathered in a pan
of kerosene by sweeping a twig back
Ia, tI,o
the trees with paris green or other arsen-
lite will sometimes be found an efiectua!
and convenient remedy. On the whole,
however, prevention by destruction of
the egg clusters is better than any rem
edy. If the trees are carefully eXamn-
ed during the fall or winter, the egg
clusters may readily be seen and can be
removed by cutting of the twigs on
which they have been formed. Every
egg mass obtained lessons the number of
caterpillars likely to appear in the
spring by about 400. Unless an orchard
is infested by migration from adjoining
trees, this plan thoroughly carried out
will prevent further damage. If there is
either an orchard or grove of NAPLES or
oaks near by, it VIII be well to keep
sharp lookout during May and June for
migration. Damage from this source
may often be checked if not prevented
by placing bands of well tarred paper,
burlap, or any convenient cloth about
the trunks of unattached trees. When
mature the worms cease feeding and
probably little damage will be done
after the LIST of July.
Insect enemies. Fortunately the forest
tent-caterpillar is attacked by several
parasites, which prevent its increase so
effectually that it is seldom very destruc-
tive for many years in succession.
There are also several beetles which de-
your the larva in considerable numbers.
Anyone desiring further information
should write to the Experiment Station,