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.