First Detection of Pest in Maryland
ANNAPOLIS, MD (July 23, 2025)– The Maryland Department of Agriculture and USDA Animal and Plant Health Inspection Service (USDA APHIS) have confirmed the presence of box tree moth (Cydalima perspectalis) in a state park in Washington County. This is the first detection of this destructive pest in Maryland.
The box tree moth (BTM), a federally regulated insect, is a destructive pest of boxwoods, feeding primarily on them. They can produce multiple generations per year and, if left unchecked, can destroy the plant. BTM was first found in the United States in New York in 2021 and has rapidly spread with populations found in Delaware, New York, Massachusetts, Michigan, Ohio, Pennsylvania, and West Virginia.
Early detection is the key to preventing significant damage, loss and spread of the box tree moth. For information on how to identify and treat this pest please visit the University of Maryland Home and Garden Information Center website.
What You Can Do
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Monitor boxwoods in your landscape, looking for defoliation, bark stripping and webbing with caterpillars.
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The caterpillars are lime-green with thin black stripes and can be difficult to see when small. Full grown caterpillars can grow to 1.5 inches. They are voracious feeders, and heavy infestations can completely defoliate host plants. Once the leaves are gone, they feed on the bark, eventually killing the plant.
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Webbing, created by the caterpillars, is most noticeable.
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Adult moths generally have white wings with a wide brown border. They are most active at night and may be hard to detect.
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Infestations may not be noticeable until significant defoliation occurs.
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Allow Maryland or Federal agricultural officials to inspect your boxwood plants and place detection traps.
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Any infested material should be doubled bagged in plastic bags and placed in the trash.
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Nursery owners should monitor their boxwoods and implement safeguards to limit pest risk. All licensed nurseries should report BTM detections to the Maryland Dept of Agriculture Nursery Inspection Program or reach out to their nursery inspector.
The department will be working with the Maryland Department of Natural Resources on a treatment plan for the positive boxwood plants found in the state park as well as USDA APHIS Plant Protection and Quarantine to develop a federal quarantine for the pest.
If you suspect your boxwoods may be infested with the box tree moth, please contact via email the Plant Protection and Weed Management program at ppwm.mda@maryland.gov. Please attach a picture in your email.
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