PUBLIC NOTICE: Box Tree Moth Quarantine Expanded to Four Additional Maryland Counties

ANNAPOLIS, MD (August 24, 2026) – Effective today, August 24, the Maryland Department of Agriculture (MDA) and the U.S. Department of Agriculture Animal and Plant Health Inspection Service have expanded the box tree moth (Cydalima perspectalis) quarantine into Caroline, Cecil, Kent and Queen Anne’s counties. The box tree moth has been confirmed in Caroline, Cecil and Queen Anne’s counties, and while not yet seen in Kent County, the locality is being included due to its proximity to the confirmed counties and Delaware. The quarantine will restrict the movement of regulated articles within the confined area.

There are now eight Maryland counties under box tree moth quarantine - JPG - 3.54 MB. In March 2026, a quarantine order was put into place for Allegany, Frederick, Garrett and Washington counties due to their proximity to nearby states with established box tree moth populations and a confirmed positive recorded in Washington County.

Businesses that grow and ship boxwoods are required to have a certificate of inspection and complete a compliance agreement with MDA to move regulated items into or from the quarantine zone (found on MDA’s website). Nursery owners and residents within the quarantine zone are encouraged to monitor their boxwoods and implement safeguards to limit pest risk. Early detection is key to preventing significant damage and loss, as well as the spread of the box tree moth. 

The box tree moth is a federally regulated insect that is native to East Asia. It was first identified in the United States in 2021 after being confirmed in New York and has rapidly spread to Delaware, Massachusetts, Michigan, New Jersey, Ohio, Pennsylvania, Virginia and West Virginia. Caterpillars are lime green with thin black stripes and can be difficult to spot when small. Full grown caterpillars can grow up to 1.5 inches. Adult box tree moths have white wings with a brown border. They are generally active at night and may be hard to detect. 

The insect poses a major threat to the region’s nursery industries as it feeds primarily on boxwoods, an important ornamental shrub used in landscaping. Early infestations are often hard to detect as the molting caterpillars generally feed on the underside of the leaves, and multiple generations can live off the shrub as the box tree moth has a short development time. This intensive feeding limits shrub recovery, and once it is fully defoliated, or cleared of leaves, the caterpillars will eat the bark, cutting off its supply of water and nutrients, a process called girdling. This will fully kill the shrub. 

What You Can Do

• Monitor boxwoods in your landscape, looking for signs of defoliation, stripped back and/or caterpillar webs. (Note: Ensure webbing is from caterpillars and not from spiders. Caterpillar webbing will be very noticeable.)
• If you suspect the presence of box tree moths, report it to MDA through this online form
• All state and/or federal agricultural officials to inspect your boxwood plants to place detection traps. 
• Prune out localized infestations and cut the tree down to its base, or completely remove the infected shrubs.
• Any infested shrub material should be double bagged and placed in the trash so the moths do not escape.

For more information on how to treat this pest, please visit the University of Maryland Home and Garden Information Center or read more about the Box Tree Moths. For any questions, please email [email protected].