May 24, 2016

Canadian growers now fight against corn borers

Canadian growers battled a new insect, the European corn borer, during the 2015 season. While the insect is typically attracted to maize and other grain crops, the corn borer has moved on to potatoes.

Ian MacRae, Extension entomologist at Minnesota’s Northwest Research and Outreach Center, said the corn borer has on damaging effects on potatoes.

Here’s more from the Manitoba Co-Operator:

When it hits potatoes it’s devastating — the young burrow into the stem in the potato, near a leaf axil, eating out the pith and vascular tissue, causing wilting or weakening the stem, lodging the plant so the leaf and stem fall down,” said MacRae. “And their entry points serve as sites for secondary infection.”

Corn borer will utilize alternate hosts if preferred hosts are not available. For example, if nearby growers are using Bt corn resistant to pests.

MacRae said growers should maximize natural mortality of the insect and decrease insecticide use. That will encourage predation of corn borer as eggs and young larvae by ladybird beetles and other predators and native parasitoids.

Photo: Manitoba Department of Agriculture

“