Forest tent caterpillars setting up camp in Winnipeg

Forest tent catepillars are appearing in Winnipeg. .
Forest tent catepillars are appearing in Winnipeg. . Randall Paul/Global News

WINNIPEG – Forest tent caterpillars are climbing and crawling on trees all around Winnipeg and this year there could be more than usual.

“There’s lots of forest tent caterpillar activity so we are seeing that cycle anywhere from 10 – 15 years on average. The last big outbreak was 2003 and now we’re seeing that next one,” said Taz Stuart, entomologist with Poulin’s Pest Control.

The cycle could be peaking this year, although it’s impossible to know for sure until the following year’s population is observed.

More forest tent caterpillars would be bad news for trees, particularly the varieties they prefer to feed on like American Elm, Manitoba Maple, Green Ash, Poplar and ornamental species.

They feed on leaves which causes defoliation. This weakens the tree and leaves it more vulnerable to insects and other diseases.

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Forest Tent Catepillars

The city is spraying for the caterpillars, using an organic compound called BTK.

The program is targeting areas that are the most vulnerable to defoliation.

Right now the largest concentrations of the caterpillars appear to be occurring in newer parts of the city, said Stuart.

He said if homeowners wish to get rid of the caterpillars themselves, they have options, “If you’ve got a small tree, manual removal, scrape them off and take them down. You can buy contact insecticides, malathion, there’s permethrins you can spray on that will kill them too.”