Gypsy Moths:
Unwelcomed Invaders
By: Barry Tanner
General
Female Description Male
Origin
Scientific name: Lymantria dispar (Linnaeus) - Gypsy moths “GM” are native
to temperate hard wood forests of Europe and Asia.
Appearance & Size
A mature female is the bigger of the species with a white body and a two
inch wing span. Her wings fold back over her body but she does not fly.
A mature male is much smaller and pure brown. His wings are wide spread,
and triangular shaped, and he is able to fly.
Life Span
The life span of a gypsy moth adult (moth) is 10 to
14 days. Its only purpose in life is to reproduce.
There is just one generation per year.
Diet & Feeding Behaviour & Food
Gypsy moths are considered Phyllophagous
insect or leaf eaters. They are also known as
free-living defoliator because the larvae over-
consume the foliage of hardwood trees. These
host trees are American beech, apples, ashes,
balsam fir, cherries, plums, eastern hemlock,
gray birch, hickory, larches , tamaracks, pines,
poplars, aspens, cottonwoods, red maple, red
oak, spruces, sugar maple, trembling aspen,
white birch, white elm, willow, and so on.
Gypsy moth caterpillars feed on developing
leaves and buds in May. Newly hatched larvae
feed by chewing small holes in the surface of the
leaves. Once matured into a moth they do not
eat and die soon after mating and laying their
eggs.
Arrival into Canada
Gypsy moths were first discovered in British Columbia in 1912. Spongy egg
masses were found on young cedars imported from Japan. They were
destroyed before hatching.
Canada’s first infestation was in 1924 in southwestern Quebec, near the U.S.
border. The second infestation happened in 1936 in New Brunswick. The bugs
were destroyed by massive egg removal operations.
The moths were again discovered in Quebec in 1955. The moths managed to
evade the efforts of Canada's
government and have become
entrenched in southern Ontario,
New Brunswick, Nova Scotia and
British Columbia. Population
size differ yearly, depending on
the region. It now thrives in
eastern US and Canada.
Note: Gypsy moths were introduced to the US in 1868 by
a French scientist, Leopold Trouvelot. He imported gypsy
moth eggs to experiment in making a silk caterpillar hybrid
that could be disease resistant. Several moths escaped
from his lab during a wind storm, and the rest is history.
It is now one of the most infamous insect pests in North
America
Canada: before the “GM”
With a balanced and healthy ecosystem,
Canada’s forests thrived.
Biodiversity was everywhere.
Natural disasters and diseases were the
main challenges for our forests.
Canada: after the “GM”
Many thousands of acres of Canadian forests have been
totally defoliated each year by “GM”. Some trees recover
but many die because they cannot perform photo-synthesis
due to lack of leaves. Serious infestations of “GM” can cause
a major drop in the biodiversity of trees in certain areas.
Total defoliation
Problems
“GM” have caused many problems that could have
been avoided, such as:
• wide spread destruction of timber makes them useless to
loggers.
• nuts, berries, fruit trees, and vegetable gardens are also
targets which directly affects human economy.
Oak tree
Nectarine tree Squash plant
Nuisance Factor
• when the caterpillars
shed their hairs they can
affect allergies of
humans.
• when the caterpillars
explode in population
any outdoor activity can
be ruined by caterpillar
poop or invasions.
Promising Solutions
Forest Pest Management Spray Programs use both
chemical & artificial pesticides registered with the
government for caterpillar management. These
chemicals must be sprayed when the caterpillars are
juvenile for best effect.
Tangle Foot
Pest Barriers
can be
placed
around tree
trunks to
help control
the
caterpillars
movement
in and out of
the tree
canopy.
Biological Controls
Scientists have found that “GM” has naturally occurring
enemies that can help turn the table for the trees.
Examples are the following:
Caterpillar cadavers (brown
things inside box) are Predators (deer mice)
covering a tree treated with
biological controls.
Egg parasite
Baculoviruses Bacillus thuringiensis
Fungal spores (Virus) (Bacteria)
“GM” Management Guide
for Homeowners
MID-OCTOBER—
MID-APRIL: LATE APRIL:
Obliterate egg put barrier
masses. bands on
tree trunks.
Collection
band closed
MAY–JUNE: use
insecticides.
EARLY JUNE: change
barrier bands with
Collection band open
collection bands.
Bibliography
• http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=9506
• http://wiki.answers.com/Q/Why_is_the_gypsy_moth_called_the_gypsy_
moth
• http://www.hc-sc.gc.ca/cps-spc/pubs/pest/_pnotes/gypsy-
spongieuse/index-eng.php
• http://zimmerair.com/services/forest-pests/
• http://cfs.nrcan.gc.ca/news/438
• http://www.planetnatural.com/site/xdpy/kb/gypsy-moth-control.html
• http://www.uwex.edu/ces/gypsymoth/homeowners.cfm
• http://www.invasivespeciesinfo.gov/animals/eurogypsymoth.shtml
• http://www.Google.ca
By: Barry Tanner