Forest tent caterpillar

Forest tent caterpillar resting on Aspen trunkThe forest tent caterpillar (FTC), Malacosoma disstria, is a native defoliator of a wide variety of hardwood trees and shrubs and can be found throughout the range of all hardwood forests in North America.

FTCs primarily feed on:

  • aspen
  • birch
  • basswood
  • oak

Quick facts

  • FTCs are often mistakenly called army worms.
  • Populations peak every 10–16 years.
  • Defoliation causes little damage. A second set of leaves will develop by mid-July.
  • There are natural control mechanisms that will cause populations to collapse.
  • FTCs are native insects and play critical roles in structuring aspen mixed-wood forests and helping to improve forest dynamics.

Fact sheet