A Fairfax County, VA, publication

Department of Public Works and Environmental Services

Working for You!

Community Gypsy Moth ManagementFairfax County Forest Pest Management Branch

May, 2015

Photo credit: Daniel Herms, The Ohio State University, Bugwood.org

2Urban Forest Management Division: Forest Pest Management Branch

What is the gypsy moth?

• Gypsy moth (Lymantria dispar) is an invasive insect pest that is native to Europe and Asia. It was introduced to North America in the late 1800s.

• The gypsy moth is called a defoliator, which means it eats the leaves of trees, particularly oaks.

Male (left) and female (right) adult gypsy moths

Gypsy moth caterpillar eating a leaf

Photo credits: USDA Forest Service - Region 8 - Southern Archive, USDA Forest Service, Bugwood.org; Minnesota Department of Natural Resources Archive, Minnesota Department of Natural Resources, Bugwood.org

3Urban Forest Management Division: Forest Pest Management Branch

What is the big deal about the gypsy moth?

• Defoliating insects like the gypsy moth can be one of the most destructive pests to plants and trees in the United States.

• Gypsy moth has caused and will continue to cause hundreds of millions of dollars in damages to private property owners.

Photo credits: Tim Tigner, Virginia Department of Forestry, Bugwood.org; Haruta Ovidiu, University of Oradea, Bugwood.org

4Urban Forest Management Division: Forest Pest Management Branch

What does the gypsy moth do?

• Gypsy moth caterpillars eat the leaves of oaks and other hardwood trees.

• Because they are invasive and non-native, their populations can explode and cause large scale defoliation of forests.

• Loss of leaves from trees from gypsy moth feeding causes stress and can contribute to the decline or death of affected trees.

Photo credits: Louis-Michel Nageleisen, Département de la Santé des Forêts, Bugwood.org

5Urban Forest Management Division: Forest Pest Management Branch

Gypsy moth monitoring and control

• Female moths do not fly; they crawl up trees or other surfaces to lay eggs in beige colored, velvety masses.

• These egg masses are relatively easy to spot and are counted to predict defoliation the caterpillars will cause when they hatch.

• Fairfax County Urban Foresters conduct annual surveys to search for and count these egg masses between July and October.

Photo credits: Jim Occi, BugPics, Bugwood.org

6Urban Forest Management Division: Forest Pest Management Branch

Gypsy moth egg masses

Photo Credits: Daniela Lupastean University of Suceava, Bugwood.org; Milan Zubrik, Forest Research Institute - Slovakia, Bugwood.org

7Urban Forest Management Division: Forest Pest Management Branch

What is an egg mass and where do I find them?

• Egg masses are oval shaped– Approximately 1 ½ inches long by ¾ inch wide– Beige or tan in color – Fuzzy and firm to the touch.

• Each egg mass contains 500 to 1000 gypsy moth eggs.

• Look for masses from the end of August until April of the following year.

Photo Credits: Milan Zubrik, Forest Research Institute - Slovakia, Bugwood.org

8Urban Forest Management Division: Forest Pest Management Branch

Where do I find egg masses?

• Eggs are laid in sheltered areas– Tree trunks– Undersides of branches– Under picnic tables– Bird houses/feeders

– Firewood piles– Eaves of houses– Disused vehicle tires/RVs– Tarps

Photo Credits: Pennsylvania Department of Conservation and Natural Resources - Forestry Archive, Bugwood.org; USDA Forest Service - Region 8 - Southern Archive, USDA Forest Service, Bugwood.org; Rusty Haskell, University of Florida, Bugwood.org

9Urban Forest Management Division: Forest Pest Management Branch

What can I do?

• You can help detect gypsy moth infestations: – Keep an eye out for the caterpillars or excessive leaf damage in the

spring.– Search your property for egg masses in mid-summer. Female moths

begin laying eggs in mid-July.

• Report egg masses in your neighborhood:– http://

www.fairfaxcounty.gov/dpwes/environmental/gypsy-moth-form.htm or scan the QR code (right)

– 703-324-1770, TTY 711.

• Become a part of a volunteer survey team on Fairfax County park land:• http://www.fairfaxcounty.gov/volunteering/• Search for “gypsy moth”.

10Urban Forest Management Division: Forest Pest Management Branch

What can I do: Search-Scrape-Destroy

• Search your property for gypsy moth egg masses after mid-July.

• You can control gypsy moth on your property by scraping egg masses into a container of soapy water or bleach solution.– A putty knife or other flat edged tool

works well.

• Avoid simply scraping eggs onto the ground. They will still hatch!

Photo credit: USDA APHIS PPQ Archive, USDA APHIS PPQ, Bugwood.org

Additional Information

For additional information, please contact

www.fairfaxcounty.gov/dpwes

11Urban Forest Management Division: Forest Pest Management Branch

Fairfax County Forest Pest Management Branch

703-324-1770, TTY 711

pestmail@fairfaxcounty.govwww.fairfaxcounty.gov/dpwes/environmental/gypsyffx.htm