New forest tent caterpillar infestation to expect: some preventive tips

New forest tent caterpillar infestation to expect: some preventive tips

New forest tent caterpillar infestation to be expected: some preventive tips

Forest tent caterpillar could make a comeback this summer

Please note that this article published in 2017 may contain information that is no longer up to date.

The forest tent caterpillar, this caterpillar that attacks the foliage of trees in certain sectors of the region , will be back in the summer of 2017, according to biologist Roger Larivière. However, it is possible to prepare to face it.

A text by Félix B. Desfossés

Watch for eggs on the branches

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A forest tent caterpillar egg ring on a tree branch

Roger Larivière explains that it is possible to identify where the eggs of the forest tent caterpillar were laid and to destroy them before they hatch. They are found on tree branches in the form of rings. The latter can contain 200 to 300 eggs.

“Last year, the female butterfly, immediately after emerging from the cocoon, there was mating with a male and the female went to make those rings. The female, of course, doesn't take a chance, she chooses the highest branches, therefore the most difficult to access”, observes the biologist.

How to proceed?

However, the female butterfly does not lay her eggs on just any shrub. It favors aspen and certain other shrubs. Thus, it is possible to cut the end of the branches where the rings are by climbing a stepladder, a ladder or by using telescopic secateurs. Once the branch is cut, “the shrub will heal and protect itself,” says Roger Larivière.

“The big thing is that this time of year you see the rings on the branches,” he says.


Once this step is completed, it is also possible to prepare the trees that are on our land to face future invasions. Roger Larivière suggests using petroleum jelly or automotive grease to make a ring around the trunks of trees. Soapy water can also be effective, as can some biological insecticides.

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Biologist Roger Larivière

A new infestation to be expected< /strong>

According to the biologist, various indicators suggest that the forest tent caterpillar will return in force this summer.

“I think that it will start to decrease this year and we will go towards a decrease in the population curve, he believes, but, you know, we are in a region where there is aspen. We are in a young forest because there has been a lot of cutting. So when 50% of our forests are populated by aspen, we kind of encourage the epidemic. »

Listen to the interview given by Roger Larivière on the show Des matins en or here.

Interview with Roger Larivière, biologist