Gypsy Moth: Natural Solutions
A gypsy moth caterpillar can eat about one square metre of leaves as it goes from a little tiny new caterpillar to a great big adult one ready to pupate. That’s a fair amount of foliage for just one little caterpillar. The voracious caterpillars are threatening Ontario’s trees, and the gypsy moth caterpillar (Lymantria dispar) isn’t fussy about what it eats. Once it’s done with the trees, it’ll even drop down and feed on understory plants and bushes.
In 2019, Ontario’s Ministry of Natural Resources and Forestry used aerial photography to determine gypsy moths had defoliated 47,203 hectares. By 2020, the damage had spread to 586,385 hectares. That’s a 1,200 percent increase. The population of gypsy moths is cyclical, with significant outbreaks every seven to 10 years.
The gypsy moth caterpillars are invading Ontario this year. It has become a significant pest because the caterpillars have voracious appetites for more than 300 species of trees and shrubs, posing a danger to North America’s forests. The caterpillars defoliate trees, leaving trees vulnerable to diseases and other pests and can eventually kill the tree.
A gypsy moth infestation at this stage lasts an average of 10 days for females and 13 days for males.
Natural Solutions
There are tried and true, all-natural methods to help homeowners regain control of their lush landscape again. Remove dead branches and stumps that protect gypsy moth caterpillars and pupae from predators. Soapy water. Spraying young gypsy moth caterpillars w
with soapy water can kill those soaked.
Caterpillars and their eggs can be destroyed by drowning them in water and dish soap or burning them in a metal container with crumpled newspaper.
Vinegar. A fragile solution of any household vinegar will deter many leaf-chewing beetles and caterpillars.
Caterpillars can be successfully trapped. To make a trap, wrap a 45-cm (roughly 17-inch) wide strip of burlap around the tree trunk at chest height. Tie a string around the centre of the burlap and fold the upper portion down to form a skirt, with the string acting as a belt. The caterpillars will crawl under the burlap to escape the sun and become trapped. Later in the day, lift the burlap. Pick off the caterpillars and dispose of them.
TIPS FOR CURBING GYPSY MOTH INFESTATIONS:
Hand-pick the least favourites – When it comes to caterpillar removal, the fastest way to address the problem is by hand—that is, by a gloved hand.
Trap caterpillars on trees under burlap and dispose of the insects
Use an insecticide to reduce numbers
Ensure trees are as healthy as possible by keeping them well watered to tolerate defoliation from the caterpillars.
Keep an eye out for egg masses later in the summer and remove them