Defoliating Caterpillars

There are many different species of caterpillars that can defoliate our trees. While these can be pests, in most years they have negligible effects on trees and are a natural part of forest ecosystems.  Several, including Eastern Tent Caterpillars and Forest Tent Caterpillars can cause heavy defoliation in some years but are different from invasive threats like the European Spongy Moth because trees typically recover. However, combined with other pathogens and insect pests they may weaken a tree making it susceptible to other problems.