Spongy Moth

Spongy moth (formerly known as gypsy moth) has been in the United States since 1869 and in Virginia since the 1980s. Most of Virginia is infested with Spongy moth, but it may not cause widespread defoliation every year. Spongy moth caterpillars feed on a wide range of trees, but prefer oak, maple, hickories, and birch, but will also attack fruit and nut trees, willow, dogwood, pine, and spruce and high population numbers can defoliate trees.  Spongy moths lay their eggs in July-August. The following spring (April-May) the caterpillars hatch and begin to feed. The caterpillars feed for 5-6 weeks on leaves. They then pupate and become moths, which cannot feed, leaving their only function to reproduce.

If you find Spongy moth caterpillars on your property, please contact Tessy Mowery, Spongy Moth Coordinator, at 540-743-4142.

Spongy Moth Caterpillar (Steven Katovich, Bugwood.org)

spongy moth caterpillar

Spongy Moth Pupae & Egg Masses (Karla Salp, Washington State Dept of Agriculture, Bugwood.org)

spongy moth pupae

Spongy Moth (John Ghent, Bugwood.org)

spongy moth

What Can You Do?

Recognizing and destroying egg masses before they hatch can reduce local populations. Starting in the fall, search your property for egg masses on tree trunks and other likely locations. Use a putty knife, stiff brush, or a similar tool to scrape the egg masses into a plastic bag or container. Cover the egg masses with soapy water and let soak for a day or two before discarding. Egg masses scraped off but left on the ground can still hatch in the spring.

What is Page County Doing to Help?

The County has begun monitoring for Spongy moth during the months of August through November to assess the potential populations for the next year. This will be done by counting egg masses. When populations are high and warrant action, Page County will participate in a voluntary aerial spraying program coordinated with the Virginia Department of Agriculture and Consumer Services and the USDA Forest Service. All landowners are notified in advance, and may opt out of spraying, if desired.

The most effective way to manage Spongy moth is by using chemical or biological insecticides.  Large trees may require specialized equipment for complete spray coverage to manage Spongy moth. There are simpler hands on approaches that homeowners with smaller properties can use. These include treating egg masses and banding trees and can be used along with insecticides available to homeowners.