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Forest tent caterpillars, on the other hand, can be seen throughout the city in multiple types of trees. Boone said their favourites are green ash, poplar and chokecherry. Avid gardeners should keep an eye on their plants; tent caterpillars have been known to munch on flowers or other greenery in their path.

Boone said many residents have already begun calling city hall to report the invaders. Most of the complaints revolve around the massive numbers, but some are also worried about the health of local trees.

ARE THEY HARMFUL?

Dr. Rory McIntosh, an insect and disease expert for the Ministry of the Environment, said people have little to worry about when it comes to caterpillars causing irreversible harm to trees.

“There is little long term damage caused by (forest tent caterpillars). They will shred all the leaves, but they will generally come back in a second growth.”

He says permanent damage to trees can happen, but it’s very unlikely, since it would take an extremely large number of caterpillars eating from the same tree for multiple years before a its health begins to decline.

COMBATING THE PROBLEM

Although the city does not attempt to control these insects because they are only considered nuisance pests — insects that don’t cause permanent damage to the environment — Boone and McIntosh both offered a few options if people want to fight the tent caterpillar problem themselves.

If a grouping of caterpillars is large, Boone suggests employing the “spray and squish” method — basically spraying them with water to remove them from trees and buildings, then squishing them on the ground.