Forest Tent Caterpillars Ravaging Northern Michigan Trees

Jun 29, 2017

Trees in Michigan’s northern Lower Peninsula are dealing with a periodic attack from forest tent caterpillars.

The caterpillars strip leaves from oaks, aspens and sugar maples. The Department of Natural Resources says widespread outbreaks happen every 10 to 15 years.

Forest health specialist Roger Mech says trees rarely die from tent caterpillar defoliation unless already weakened by drought or other stresses.

Caterpillar feeding has ended for this season, so spraying insecticides is no longer an effective control method.

Instead, landowners should make sure affected trees get at least one inch of water per week during the growing season. Applying a slow-release fertilizer in the fall can help them recover.

Removing dead or ailing trees can keep others in a woodlot healthy by providing more sunlight and reducing competition for nutrients.