The spongy moth – formerly known as the Lymantria dispar dispar (LDD), European or Asian gypsy moth – is a defoliating insect found in Ontario. At the caterpillar stage, it feeds on leaves from hardwood trees such as oak, maple, birch and poplar. Like all forest pests, their populations are cyclical and peak in intervals. Southern Ontario is currently experiencing a peak point in the spongy moth population cycle.  

Spongy moths have natural enemies that aid in reducing the population in highly infested areas. These include soil-borne bacteria, squirrels, chipmunks, raccoons, skunks, more than 15 species of birds and several native insects. The manual removal and destruction of egg masses also drastically reduces the presence of caterpillars the following season.   

City staff are currently undertaking control measures in known moth hot-spot areas to reduce the spongy moth population in the upcoming 2022 season. Residents can also help reduce the spongy moth population by taking precautions to protect trees on their property.