Lymantria dispar dispar (LDD) - "European Gypsy Moth"
The Lymantria dispar dispar (LDD) moth is native to Europe. It was introduced to Massachusetts in the 1860’s, and quickly escaped into nature. The moth is a non-native invasive insect that was first found in Ontario in 1969. The first serious outbreak in Ontario was documented in 1981 in the Kemptville area.
This insect is a defoliator, meaning it eats leaves, of many tree species in Ontario. In southern Ontario, host species include sugar maple (Acer saccharum), American beech (Fagus grandifolia), eastern white pine (Pinus strobus), balsam fir (Abies balsamea), Colorado blue spruce (Picea pungens), but their preferred host are oak (Quercus sp.) species.
Outbreaks normally last 2-3 years and population collapse is caused by natural factors such as cool wet weather, cold winter temperatures (below -20 to -25 Celcius), starvation due to lack of food, biocontrols such as nuclear polyhedrosis virus (NPV) and Entomophaga maimaiga fungus, egg parasitoids, ground beetles, and larval parasitoids.
What is GSCA Doing about LDD?
GSCA Staff are monitoring damages from the larvae stage (caterpillar) as well as monitoring for the presence of egg masses, moths, and pupae.
Ministry of Northern Development, Mines, Natural Resources and Forestry (MNDMDRF) staff complete annual aerial forest health surveys for numerous invasive species, including the LDD moths. GSCA staff communicate with MNRF staff about their findings.
Visit the MNDMNRF's Lymantria dispar dispar website for more information and to view a map of areas defoliated by LDD moth across Ontario.
For more information on how to identify LDD, their lifecycle, and how landowners can help stop the spread of this invasive species, please visit: