The Somerset reporter. [volume] (Skowhegan, Me.) 1868-1909, 1899-07-06
The Forest Tent Caterpillar.


for more than century, but within the
past three years it has been doing much
damage in some parts of New England and
New York, as it has done at various times
before, in other sections.
Its common name is incorrect, as it at
tacks orchards and shade trees as readily
as the forest trees, and it does not form a
tent like the American tent caterpillar, so
abundant some years in apple and wild
cherry trees. When ready to make its CO.
coon some will draw leaves together by
webs, and cover themselves in them, while
others will seek shelter on the bark of the
tree or the sides OF buildings. When feed
ing they spin fine silk thread, which they
keep beneath their feet as they go, and if
the tree is Jared they spin down upon
that thread.
This alone would distinguish them from
the tent caterpillar, which they much re-
semble in appearance, excepting that the
latter has continuous white stripe along
the back, while the forest caterpillar has a
broken line or succession of white spots
about twice as long as they are wide.
The moth is a bro xnish moth, which
usually appears the latter part of June, and
will lay its eggs in band about the small
twigs of the tree near the end OF the twig.
These hatch out if undsturbed the next
spring, about as soon as leaves appear on
the trees. They begin eating at once, and
in about two weeks have grown so that
they must shed their skins. Then they
can DE found in clusters on the trunk Of
the tree. They shed their skins usually
four times before they attain full size, be-
ing then two and one-half to three inches
long. When fully grown they form their
cocoon of white silk and in this form may
be found for about ten days, when the
moth comes out to deposit her eggs.
Seldom do they remain to do much in
jury for more than three years in one
locality, when nearly all disappear, and for
many years only few will be found. A
part of this may be due to their greatness,
and the fact that they destroy the foliage
to such an extent that after few years of
successive severe attacks the trees die, and
the succe eding crop of insects fail TO find
food to perfect their growth. This is the
way we do not want to destroy them, as
we cannot afford the loss of the trees they
feed upon.
But when an insect becomes so very
numerous, its natural enemies are apt to
also increase in number. Some of the
beetles, like the large, black. ground bee
tie. and the green beetle, Calosoma, eat
many of the caterpillars. Skunks destroy
many of them when they are on the ground
or low enough to be reached. The ich-
neumon flies, sometimes called dragon
flies and devils darning needless" de-
post their eggs in the body of these, as in
many other caterpillars. and the grub
which develops finally kills the caterpillar
before it can transform to the perfect
moth again. There are also either insects
that attack them, and, like the true tent
caterpillar of our orchards. they may be
sometimes attacked by contagious disase
that will spread so rapidly as to destroy
whole colonies of them. The entomologist
of the Experiment Station of Minnesota
reports that in 1898 he found caterpillars
thus diseased in colony of the orchard
tent caterpillars in small grove, and he
took the diseased caterpilars to other
groves where there were nests, and forests
that were attacked, and wherever they were
placed, the healthy worms were soon dis
.eased and the greater majority of them
died. A similar disease has been noticed
among the forest caterpillars in some parts
of New Hampshire.
Birds destroy some of them. Our Ameri-
can cuckoos make business of feeding
upon them, and Miss Soule of Vermont
observed cuckoos, robins, orioles, chip
ping sparrows, catbirds, redeyed, white
eyed and warbling vireos. cedar birds and
nuthatches feeding upon the caterpilars.
Many of these also were seen to catch and
eat the moths in considerable number, and
he nut matches and chickadees tore open
and ate the cocoons. The English spar
row was not seen to eat any of the cat
erpillars.
We mention these natural enemies of
the two varieties of caterpillars that they
may be protected and encouraged when
they are seen in either orchards or forests.
But when they are so abundant, we can
not depend upon these things alone to
fight against them. God helps those
who help themselves" and we can easily
destroy many of them. First in the egg.
Each little cluster near the ends of the
twigs in infested trees contains from 200
to 400 eggs. As they are covered in win
ter with a varnish-lke substance which
glistens in the sun, they can be readily
seen when the trees are bare of leaves,
and with long handled pruning shears the
twig should be cut off and burned. In
and about the city Of Rochester, N. Y,
school children were encouraged to find
and bring in these egg clusters by the pay
ment of few cents hundred for them,
and many thousands were thus gathered