Tent Caterpillars are here but it looks like they will not be causing the destruction commonly associated with their kind.

Nests of the fuzzy insects have been seen across the region but, as Provincial Pest Management Biologist Fiona Ross explains, most of them are eastern tent caterpillars and not forest tent caterpillars; an important discrepancy.

“We often think about the forest tent caterpillar and that is the one that causes the large-scale defoliation of poplar trees,” details Ross. “This other one, this eastern tent caterpillar, doesn’t generally cause that much damage.”

While the two species look very similar to the untrained eye, Ross says eastern tent caterpillars live together in a larger tent-shaped webs between tree branches and usually feed on the berries and hardwoods close to their homes. “That is where they are going to hang out,” she offers. “They will leave to feed and then they are going to come back to that nesting area.” They do not typically devour entire sections of forest like their wandering cousins.

Where forest tent caterpillars are tricky to deal with as they tend to spread out and cocoon on any available surface, Ross says the eastern variety can simply be taken care of by removing their nest and disposing of it.

Both species, she adds, are native to southern Manitoba and the plants they feast on do have natural defenses.

“If the leaves do get eaten, the trees have reserves built in them and they should produce a second set of leaves once the caterpillars are finished.”

Still, Ross says the impact the eastern species has on its environment is so minimal that the province does not monitor their levels. The levels of the forest tent caterpillar, however, are measured and she does not expect their numbers this summer will be significant.

“They are pretty low across the province,” she indicates, citing a survey done in 2019. “There were a few little pockets of them seen in southeastern Manitoba last year, but the population is definitely declining.”

So, if you do happen to see one of the gray-blue caterpillars wriggling across your lawn this season, know that your beloved canopy is probably not in serious danger.