Lymantria dispar
Copyright, Michael Borsch
European Gypsy Moths are
perhaps the greatest insect pest
in the United States. They were accidentally released by a
professor doing research on silk production in
Massachusetts. Since then, they have spread across the
United States. Male and female gypsy
moths look very different. Females are seen most often,
because they can't fly. They are also larger, growing to
almost two and a half inches long. They have yellowish-white
wings with dark wavy lines and dots. They have a very hairy
thorax
(middle section, behind the head) and a fat abdomen
(rear body section). They have thread-like antennae. Males are smaller (about
3/4 inch) and plain brownish-gray. They have large feathery
antennae.
Copyright, Michael Borsch
It is the
caterpillars
that do all the damage to trees. Gypsy moth caterpillars
emerge in late April and feed on many types of trees until
July. Caterpillars are easy to identify because they are
large and hairy, with five pairs of blue tubercles (bumps)
in front, and six pairs of red tubercles in back. Gypsy moths' favorite
trees and shrubs
include: oaks, basswood, birch, Sweetgum, willows, and Witch
Hazel. Some other trees they will eat include: hickories,
maples, Black Cherry, American Elm, Sassafras, hornbeam, and
Eastern White Pine. Sometimes they eat other
species too, but they never eat Eastern Redcedar, dogwoods,
or ash trees. Because moths never eat them, these trees are
helped by the moths which get rid of their competition. EEK! Environmental
Education for Kids John Ghent When caterpillars are
fully grown, they become pupae
(resting stage). European Gypsy Moth pupae are brown
cocoons,
stuck to the bark
of trees. When adult
moths come out of their coccoons (about two weeks), they
mate. Males are strong fliers, but females must crawl. After
mating, females lay huge eggs masses on tree trunks or on
the sides of buildings. A female will cover her eggs with
hairs from her body. She may lay 400 eggs in one mass. Eggs
overwinter
and hatch in the Spring. Caterpillars eat huge
amounts of leaves, often stripping an entire tree, or even a
whole section of forest, bare. This is called
"defoliating." When gypsy moths
defoliate a tree, it cannot feed itself and it will die.
Many of the trees European Gypsy Moth caterpillars eat,
especially oaks, supply wildlife with food and
shelter.
Therefore, this insect is very dangerous for animals and
even people. Scientists are trying to find ways to control
gypsy moths. Fortunately, gypsy moths
have many predators,
including: birds, frogs, toads, skunks, raccoons, foxes,
turtles, snakes, beetles, squirrels, chipmunks, bats,
shrews, and lizards. These caterpillars have
an interesting behavior called "ballooning." They climb to
the top of a tree and spin a silk thread which they let
dangle. When the wind catches the thread, the caterpillar
lets go and goes for a ride. Sometimes the wind carries the
caterpillar far, but most of the time they land near the
base of the tree. Virginia Tech
