Gypsy moth (Lymantria dispar) is a Federal and State quarantined leaf-eating insect that is a serious threat to many forest trees and ornamental plants. It is easily moved into new areas by unsuspecting people, as it will hitch a ride on vehicles and other outdoor articles.
The larva or caterpillar is the damaging stage of the insect as it eats leaves from trees in the spring. Caterpillars typically will be noticed when they are feeding on trees and ornamental plants in the month of May and early June.
A single gypsy moth caterpillar can consume as much as one square foot of leaves per day. When populations reach outbreak proportions, the caterpillars can completely defoliate trees over a wide geographic area, leaving a bleak winter-like landscape in their path.
Gypsy moth is a pest of several hundred species of trees and ornamental plants. It prefers hardwoods such as oak, hickory, and maple; however, there are very few trees and shrubs that are not on the insect’s menu.
Why is Gypsy Moth a Concern ?
- Consistent or repeated defoliation over several years can have devastating effects, often leading to tree mortality.
- Fecal pellets from the feeding caterpillars rain down into people’s yards and public areas, making it difficult to enjoy the outdoors.
- Caterpillars invade outdoor living areas in mass migrations, and hairs from the insect may cause allergic reactions in some people.
- Gypsy moth is easily moved to new areas by unsuspecting human activities.
- Millions of dollars have been spent to lessen the impact of gypsy moth in other states.
- The longer we can keep gypsy moth out of Iowa, the less the long term economic impact will be.
Gypsy moth is thought of as much as a "people" problem as it is a tree problem. Defoliation often occurs in populated urban areas where homes have been built in what once was forest land. The caterpillars can be a major nuisance as they crawl and get into literally everthing.
Caterpillars leave debris from their feeding activities which can be unpleasant to clean up. And to add further distress to the homeowner, damage from gypsy moth caterpillars can be severe enough to kill trees, which then become a public hazard and a fiscal concern for removal and replacement.