Hungry caterpillars stripping trees in Quebec, Ontario and on Montreal's Mount Royal

Biologists are tracking the spread of a bumper crop of hungry caterpillars that are eating their way through some of Quebec and Ontario's best-known green spaces.

An entomologist with the Montreal Insectarium says the gypsy moth caterpillars have been especially present in Gatineau's parks and on Mount Royal, where some trees have been almost entirely stripped of their leaves.

Andre-Philippe Drapeau Picard says the caterpillar's population tends to rise and fall in cycles, and that mild temperatures last winter may have contributed to higher-than-average numbers this year.

He says the caterpillars don't usually cause permanent damage to healthy trees but can impact those that were already sick or weak.

James Page, a biodiversity specialist with the Canadian Wildlife Federation, says his group is working with the federal government to track the spread of the invasive moth with the help of the public.

He's encouraging anyone who spots the caterpillars and moths to report their sightings on the iNaturalist website so experts can track their populations and see if they're expanding outside their traditional range.

- This report by The Canadian Press was first published on July 7, 2021.

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