It’s “the year of the forest tent caterpillar” in Saskatoon.
Thousands of the tiny black, green, yellow and white insects are crawling their way up local trees and homes in their search for food. The good news, is the bug is relatively harmless.
City of Saskatoon pest management supervisor Jeff Boone said tent caterpillar outbreaks come in cycles of three years. The city received lots of calls about tent caterpillars the last two years, so Boone is not surprised they have received even more calls this year. Though unusual, outbreaks can last up to six years.
“Anecdotally, based on the call volume and based on the good conditions we had this spring, I would say that they’re higher this year than they were last year,” Boone said.
Boon said the city does not trap or spray the bug and has no official numbers.
Tent caterpillars’ favourite food are Green Ash and Chokecherry trees, but they will eat just about any kind of leaves. The small bugs gather in large numbers and can be unsightly.
However, Boone said the caterpillars are known as a “cosmetic insect” and their damage to trees is minimal. Trees would require several years of high defoliation before they would suffer. Tent caterpillars feed quickly and by early July, most are in their cocoons or have turned into moths.
The best way to get rid of tent caterpillars is to spray them with water to knock them off trees and homes. If the water does not drown them, they are then easier to squish on the ground.
Boone said cankerworms and leafrollers are out this year but in relatively normal numbers. Tree banding can prevent cankerworms but won’t stop tent caterpillars and leafrollers. They should be placed on trees from September to May so the bugs can’t lay their eggs. Bands should be removed before June because moisture under them can cause the tree to rot.
Dry weather conditions have also minimized the mosquito population, according to Boone. He said with a shrinking habitat, the only mosquitoes they have encountered are varieties that lay their eggs on the water’s surface.