The Vermont watchman. [volume] (Montpelier, Vt.) 1883-1911, 1898-06-08
AGRICULTURAL.
Forest Tent Caterpillar.

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 Expert
ment Station in Bulletin go, from which
the following description is condensed:
The forest tent caterpillar may -four
ish for some time in forests before it
attracts attention, and then may sud-
denly migrate to adjacent orchards
where it appears 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
30 in single file. In about two weeks
they are of yellowish brown color,
and later begin to take on the colors of
the mature insect. The fully grown
caterpillar is 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, yellow
ish-brown hairs are sparsely scattered
over the body. On each joint, except
the eleventh, there are two black, shin
ing tubercles from which arise few
fine black hairs. The caterpillars be-
come mature about the first week in
June. AT this lime they cease feeding
and do not, as before, collect in groups,
but wander singly over The tree, or
sometimes away from it in search of
shelter for the cocoon.
Food. 1t is more general feeder
than is the common tent caterpillar and
feeds on all our common fruit trees,
and on naples, oaks, walnuts, poplars,
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 a
corresponding 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. Proven
ton, however, is not always possible
and remedies must be used. After the
caterpillars have become established in
grove or orchard it is not easy to dis
lodge them, but something may be done
to check their ravages.* If, as may
very likely occur, they gather in clus-
tiers on the trunk they may be crushed,
and this should be done promptly for
the opportunity may not come again.
The clusters are most commonly formed
in early morning or at dusk. A much
less efficient method, but one which
may be at the time the best which can
be followed, is that of vigorously jarring
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 and forth under
the branch. Spraying the trees with
paris green or other arsenite will some
times be found an effectual and con-
venient remedy. On the whole, how
ever, prevention by destruction of the
egg clusters is better than any remedy.
If the trees are carefully examined dur
ing the fall or winter, the egg clusters
may readily be seen and can be remov-
eo by cutting off 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 Or
chard is infested by migration from adj
joining trees, this plan thoroughly car
ried out will prevent further damage.
II there is either an orchard or grove of
naples or oaks near by, it will be we'll
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 we'll
tarred paper, burlap, or any convenient
cloth about the trunks of unattached
trees.+
Insect enemies. Fortunately the
forest tent-caterpillar is attacked by
several parasites which prevent its in
crease 30 effectually that it is seldom
very destructive for many years in sue
cession. There are also several beetles
which devour the Larvae in considerable
numbers.
Anyone desiring further information
should write to the Experiment Sta
ton, Burlington, VT, which will 30 far
as possible fully and freely answer
questions.
'Now that the worms are nearly full
grown and the nests conspicuous many may
about the end OF pole, fastened by bit of
wire and soaked with kerosene may be APP
Piled both to the nests and clusters OF
worms. 1t may be necessary to 60 over the
trees second time
and probably little damage will be done al
ter the first Of July