Saskatoon is dealing with a spike in its forest tent caterpillar population. During such an outbreak, the large number of insects can be a nuisance in yards and for the city’s urban forest.
The city said this is the third year of a tent caterpillar outbreak, which usually last three to seven years.
Forest tent caterpillars feast on a large variety of trees and can cause heavy defoliation. It’s typical for trees to recover and grow new leaves.
City officials said you’ll see them crawling around until mid-June. Many of the caterpillars are now looking for a spot to pupate and will emerge as moths within the coming weeks.
Cankerworms and leafrollers are also an annual issue for Saskatoon’s urban forest.
During June and July, cankerworms are primarily found on the foliage of American elm and Manitoba maple trees. They can be seen hanging from silken threads underneath infested trees.
The larvae of leafrollers will feed from mid- to late-June while concealed within leaves that are tied together with silk webbing. Ash trees are their preference, but they also attack other tree species.
The city does not control these three pests as they typically don’t impact the health of the trees. Homeowners interested in controlling them on their own can consult their local garden centre.