While disease can start out as a minor issue for a tree, it can develop into a significant problem that threatens your property. Insects and diseases can quickly turn your shrubs and trees into liabilities if left untreated. Plants can acquire pathogens from other plants, affecting any part of the plant, including leaves, shoots, stems, crowns, roots, tubers, fruit, seeds, and vascular tissues. It is also important to apply any treatment as soon as possible because the insects spread quickly. Find more information about common tree pests and diseases in Ontario.
Spongy Moth
- The Spongy Moth (Lymantria dispar dispar) is native to Europe and is a defoliating insect found in Ontario. The first detection of spongy moth in Ontario was in 1969 and had spread noticeably across the Province by 1981.
- This insect is considered to the "invasive" due to the fact that it has moved outside of its native habitat and threatens local ecosystems.
- Although it is believed the Spongy Moth prefers oak trees, the moth actually feeds on a wide variety of trees, including oak, birch, aspen, and various hardwood and softwood trees.
- Learn more about the Spongy Moth and other Invasive Species.
Emerald Ash Borer (EAB)
- Emerald Ash Borer is a forest pest native to Asia that has killed millions of Ash trees in southwestern Ontario and the Great Lakes States.
- The Emerald Ash Borer attacks both healthy and stressed Ash trees when its larvae tunnel through the tree’s vascular system which delivers water, nutrients and sugars throughout the tree.
- West Lincoln has experienced a high occurrence of tree damage from the Emerald Ash Borer in previous years. As part of our Ash Tree Replacement Program, staff removed and replaced infected ash boulevard trees with healthy trees and continue to monitor and reassess tree conditions.