Moths

Gypsy Moth Management

In North America, the current gypsy moth range covers all of the northeastern United States, part of the Southeast and Midwest, and sections of eastern Canada. The gypsy moth's range is expanding at a rate of about 21 kilometers a year. Scientists are working to slow this expansion, using a number of methods.

The gypsy moth, Lymantria dispar, is a devastating forest pest. It feeds on the foliage of hundreds of plant species in North America, but most commonly on oaks and aspen. In heavily infested areas, trees may become completely defoliated.

Eradication

In areas without established gypsy moth populations, pheromone traps are used to detect new populations. State and federal agencies can then work together to eradicate any newly detected infestations. Eradication methods can include chemical or biological pesticides and mass-trapping.

Suppression

The worst effects of gypsy moths occur at high population densities. In areas that are already highly infested, suppressing the population as much as possible can minimize damage to trees. This is usually accomplished using ground applications of pesticides to individual trees, and aerial application of pesticides to larger areas.

Biological Control

In an effort to minimize the use of pesticides, research scientists are focusing on the gypsy moth's natural enemies. Some, such as birds, do not have a substantial effect on populations. However, the following natural agents can cause considerable mortality:

insect parasitoids and predators

small mammals, including deer mice and shrews

wilt, a disease caused by the nucleopolyhedrosis virus

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