Gypsy Moth - Information from MNRF

Posted On Wednesday July 15, 2020
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Gypsy moth is an introduced pest, and as such is a regulated pest by the federal government under the mandate of the Canadian Food Inspection Agency.

Gypsy moth is widespread across Ontario and can be found south of a line from Sault Ste. Marie to Mattawa and is beyond the stage where it can be eradicated, and also beyond the stage where its population can be suppressed to keep it from reaching outbreak levels. Gypsy moth is expected to continue to have periodic population increases. In some years it will reach outbreak levels and cause defoliation, and with repeated years of attack may cause mortality. Outbreaks typically collapse within a few years from the combined effects of predators, parasites, starvation, and diseases such as the gypsy moth virus.

When outbreaks do occur, property owners, landowner groups and municipalities may wish to conduct spray programs or take other actions to keep the trees from being defoliated. The usual goal is to keep the trees alive and healthy until the natural controls can bring about the collapse of the outbreak.

The MNRF does not currently conduct control programs for gypsy moth but does undertake annual surveys to aerially map the defoliation caused by gypsy moth which can be useful information for those considering control actions on their lands. MNRF also provides scientific advice and guidance to landowners, municipalities, and others on gypsy moth biology, egg mass surveys, and control programs.

How can you manage it?

The MNRF program focuses on outreach and education for this species, including communicating to the public about identification, impacts, and the steps people can take to reduce the spread of invasive species from one location to another. Their program does not have a role in the physical management of Gypsy Moth, but there is some good information that may be helpful available at the following websites to help manage them on your property. The websites describe the identification of the gypsy moth at its various life stages, which in turn will guide management techniques. Burlap wraps and tape bands are good options to try and capture/remove as many caterpillars as possible at a time. Captured caterpillars/ moths can be put in a bucket of dish soap and water to drown them.


If you require further assistance please contact MNRF at either of the toll free numbers 1-800-667-1940 or 1-800-387-7011.