Sugar maple borer

Distribution

Eastern Canada

Micro-habitat(s)

Trunk

Damage, symptoms and biology

Signs of the sugar maple borer's presence can be observed on the trunk of affected trees at the outset of an infestation. Galleries excavated by the young larvae can be recognized from the bark dust piles soaked with sap that are present near egg-laying sites. Another obvious sign of attack is the presence of an elongated swelling in the bark, which will eventually split open, leaving a wound.

Damage results from the larval galleries which disrupt sap flow and reduce the tree's vitality. Some branches will die after being cut off from the sap supply, and if there are many galleries, the whole tree may die.

This borer has a two-year life cycle that is spread over three calendar years. In the fall of the second year, the larvae tunnel about 10 cm deep into the sapwood and create a chamber in which they overwinter and then pupate the following year.

Life cycle (East of the Rockies)

Other information

The sugar maple borer, believed to be native to North America, is considered the most destructive pest of maple in Canada. Its geographic range corresponds to that of sugar maple, and thus extends through the Appalachian Mountains and southward in the United States. Since borer damage is located on the trunk and can kill the tree, this insect is a source of concern for North American sugar bush operators. Silvicultural practices designed to prevent outbreaks of the insect in maple stands and ornamental trees are as follows:

1. Do not harvest too many trees and do not permit livestock grazing in maple stands;
2. Cut and promptly burn infested trees or tree parts to prevent the adult insects from emerging;
3. For ornamental trees, insert a wire deep into the galleries in order to kill the larvae;
4. During summer, look for dust piles on the trunk and destroy the young larvae by cutting through the bark into the galleries with a knife.

Main host(s)

Red maple, silver maple, sugar maple