The Gypsy moth (Lymantria dispar dispar) is an invasive and highly destructive insect that is seriously threatening North American forests. At least 10 Indiana counties have documented infestations and have been quarantined to prevent the spread of material that may host the moth. See if your county is affected by clicking here.
It takes approximately one year for the moth to complete its lifecycle, but it is during the caterpillar stage that the species causes the most damage. In this 7-10 week period in summer, the Gypsy moth caterpillar will consume a substantial amount of leaf material.(1) This defoliation stresses the trees and causes them to become weak and vulnerable to other diseases and pests. If the stripping is repeated over 2-3 years, the tree will be seriously weakened.
Although the Gypsy moth will eat from more than 500 species of trees and shrubs, it prefers a handful of species.(2) Click here to see a full list of trees favored by the Gypsy moth caterpillar.
Over 8 million acres of Indiana is covered with either forest or timberland, making it very susceptible to damage from the Gypsy moth. (3) Trees in urban areas are even more vulnerable as they are already weakened by other factors.
Find more details on spoting and eradicating the moth on the Purdue Extension website.