Native Insects
Click below for other insects:
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 Gypsy Moth because trees typically recover. However, combined with other pathogens and insect pests they may weaken a tree making it susceptible to other problems.
Two-lined Chestnut Borer
The two-lined chestnut borer (Agrilus bilineatus) is an endemic beetle native to North America that attacks stressed or weakened oak trees. Larvae of the beetle construct galleries in the inner bark of trees, cutting off the flow of water and other nutrients. This causes drought-like symptoms and tree death from the top down. Two-lined chestnut borer is found throughout the eastern US and west to the Rocky Mountains. Alone, two- lined chestnut borer may act as a natural thinning agent for aging or weakened stands. However, combined with other stresses, (ex. European Gypsy Moth defoliation), two-lined chestnut borer may become a more significant cause of mortality.
