Community Gypsy Moth Management Fairfax County Forest Pest Management Branch

1. A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
Community Gypsy Moth Management
Fairfax County Forest Pest Management Branch
May, 2015
Photo credit: Daniel Herms, The Ohio State University, Bugwood.org

2. Urban 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.
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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

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

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

5. Urban 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.
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Photo credits: Jim Occi, BugPics, Bugwood.org

6. Urban Forest Management Division: Forest Pest Management Branch
Gypsy moth egg masses
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Photo Credits: Daniela Lupastean University of Suceava, Bugwood.org; Milan Zubrik, Forest
Research Institute - Slovakia, Bugwood.org

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

8. Urban 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
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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

9. Urban 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.
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• 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”.

10. Urban 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!
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Photo credit: USDA APHIS PPQ Archive, USDA APHIS PPQ, Bugwood.org

11. Additional Information
For additional information, please contact
www.fairfaxcounty.gov/dpwes
Urban Forest Management Division: Forest Pest Management Branch 11
Fairfax County Forest Pest Management Branch
703-324-1770, TTY 711
pestmail@fairfaxcounty.gov
www.fairfaxcounty.gov/dpwes/environmental/gypsyffx.htm