The caterpillar prompting questions in Barrhaven is called forest tent caterpillar. This is a native insect that can periodically reach high population levels and feed on the leaves of several tree species. We have communicated with the Ontario Ministry of Natural Resources and Forestry, and they report to be monitoring the issue with increased populations of this insect in other areas of the province, including around Kemptville.
As a caterpillar, this insect will feed on leaves of tree species such as poplar, birch, maple, and oak. Caterpillar feeding occurs during the months of May and June. In July, the insect will become a moth and lay eggs which overwinter for the following season.
Residents may see some loss of leaves (defoliation) on trees this spring as a result of this insect. Healthy trees are able to sustain loss of leaves and some trees will produce a second flush of leaves in the same season following leaf loss. It is only repeated years of caterpillar feeding that cause concern with tree health.
On their properties, residents can consider the following to reduce damage to trees and reduce caterpillar numbers:
Caterpillars can be physically removed with a broom or knocked down with a stream of water from a garden hose.
Burlap can be attached to the trunk of trees just below the lowest branches. The burlap can be attached with a string in a band around the trunk and folded in half. Often caterpillars will congregate in the burlap and this can be disposed of daily in compost etc.
City staff continue to monitor this issue. More advice or direction can be made available as the situation unfolds this spring. More details about this insect can be found at http://www.ontario.ca/page/forest-tent-caterpillar
Forest tent caterpillar Natural Resources Canada Canadian Forest Service http://www.nrcan.gc.ca/forests/fire-insects-disturbances/top-insects/13379