This article is a follow up to Carl Mansfield, tree consultant for MLF farm visit on September 7, 2019. On June 22, 2020, Deb Pella Keen, Executive Director, MLF visited the MLF farm with Ken Jewett, founder of MLF. We again observed the Lymantria dispar dispar (also known as gypsy moth) larvae feeding on several trees, and one unusual host tree, a larch. Digging in the internet we found some interesting information on gypsy moths. There are now two known species of gypsy moth invaders in North America: the European Gypsy Moth (EGM; Lymantria dispar dispar) introduced to Canada over 130 years ago and now the Asian Gypsy Moth (AGM; Lymantria dispar asiatica) which while not known to be established in Canada, was first recorded in 1991 in North American at the port in Vancouver, BC according to the US Department of Agriculture (see PDF).
Although in many ways similar to the EGM, the discovery of the Asian gypsy moth strain (AGM) in Canada has raised new concerns. According to Health Canada, the Asian gypsy moth prefers coniferous trees, is better adapted to colder climates, and the female is able to fly longer distances. These traits make the Asian gypsy moth a serious threat to Canadian forests.
The spread of the gypsy moth has been largely attributed to the movement of firewood, as well as outdoor recreational and household articles. Knowing how to detect, report and manage gypsy moth could significantly reduce and limit the spread of gypsy moth to new areas. So if you find gypsy moth larvae (caterpillars) this summer, do your part for citizen science and download this app (EDDMapS Ontario) and report your finding.
EDDMapS is a web-based mapping system for documenting invasive species and pest distribution. It was developed by the Center for Invasive Species and Ecosystem Health at the University of Georgia, and since its launch in 2005 has now expanded to include the entire US and Canada. As of June 2020, EDDMapS had over 4.9 million records.
We did our part in reporting our finding of a gypsy moth larvae at the MLF farm and while it is highly unlikely (we certainly hope!) that the gypsy moth we found was an AGM, it is important that we all learn more about these destructive invasive species.
For more information on gypsy moth in Canada and how you can control and prevent the spread of the gypsy moth see these links: