European Gypsy Moth (Lymantria dispar)

European Gypsy Moth (Lymantria dispar)

Gypsy moth was introduced to Northeastern United States in the 1860’s and has since spread to several provinces including PEI, New Brunswick, Nova Scotia, Ontario and Quebec. It is found each year in British Columbia but has not established a permanent population yet due to lots of hard work to eradicate it.


Gypsy moth overwinters in the egg stage. In the spring, eggs hatch and the gypsy moth larvae move up the tree and feed on the newly emerged leaves. They mainly feed at night so often you will see the damage to the leaves of your tree but not the larvae. Young caterpillars produce silken threads that catch in the wind and blow them to neighboring trees. More mature larvae begin to feed day and night and can very quickly defoliate your tree. You can identify them by the 5 pairs of blue spots and 6 pairs of reddish spots on their back. Once the larvae are mature (usually around July) they find a protected place such as a crevice in the tree bark, form a cocoon and pupate. Adults emerge in late summer. The males are strong fliers while females are flightless. The adults do not feed and only live for about a week… just long enough to mate and lay eggs.


Gypsy moth is a defoliator… their larvae feed on the leaves of deciduous trees for the most part, but have been known to defoliate coniferous trees as well. The prefer to feed on oak, poplar, elm, maple and birch but are not picky, and will feed on over 300 different species of trees and shrubs. The loss of foliage causes stress to the trees making them vulnerable to attack by other insects and diseases. Repeated severe defoliation can kill a tree.


The female gypsy moths will lay eggs on anything!… on or inside trees, on any solid object found under a tree like lawn furniture, toys, vehicles, trailers, boats or piles of wood or lumber. Egg masses can be transported over long distances when the materials the eggs were laid on are moved.

Not moving firewood can help prevent the spread of insect pests such as gypsy moth and many others… Burn local wood.


CFIA has more information about gypsy moth and other forest insect pests.…/e…/1330963478693/1330963579986

In PEI the gypsy moth is found mainly in the Summerside and Charlottetown areas. These areas are regulated and there are restrictions on the movement of wood from the regulated areas to a non-regulated area.…/e…/1343832991660/1343834043533