Archived Content

Information identified as archived on the Web is for reference, research or recordkeeping purposes. It has not been altered or updated after the date of archiving. Web pages that are archived on the Web are not subject to the Government of Canada Web Standards. As per the Communications Policy of the Government of Canada, you can request alternate formats on the Contact Us page.

Gypsy Moth

L. Humble and A. J. Stewart

Introduction

The gypsy moth, Lymantria dispar (L.), is a Eurasian defoliator of mainly deciduous trees. Accidental introduc-tion of the European race of the moth to eastern North America in 1868 has caused severe infestations in parts of New England, New York and Pennsylvania. In these states, and at other eastern U. S. locations, it is con-sidered a major forest pest and a seri-ous threat to urban shade trees and ornamentals.

In Canada, the gypsy moth has spread from the U. S. to become well established in Ontario and Quebec, and has been threatening parts of southern New Brunswick and Nova Scotia for many years. Though not established in British Columbia, repeated introductions over the past 15 years emphasize the need for con-tinued monitoring, eradication pro-grams, and public awareness.

The gypsy moth threat in the Pacific Northwest was increased in 1991 by the discovery in Vancouver of an Asian race of the moth; the Asian gypsy moth has broader host prefer-ences and spreads faster than the European gypsy moth. Since 1991, the insect has become a major concern for the forest industry, government agen-cies, and several British Columbian municipalities. This concern is shared by the states of Washington and Oregon which also had introductions of the Asian race in 1991.

For more information, see the Gypsy Moth Forest Pest Leaflet in the Canadian Forest Service bookstore.