Citizens Urged to Report Pest of Popular Ornamental Shrub

Contact: Dick Bean, Maryland Department of Agriculture | 410-841-5920

Citizens Urged to Report Pest of Popular Ornamental Shrub

ANNAPOLIS, MD (November 3, 2003) – Landscapers and homeowners are not the only ones that like the popular euonymus shrub. The Maryland Invasive Species Council's latest "Invader of the Month," Pryeria sinica, likes it too. Pryeria sinica, a moth that feeds on the leaves of euonymus shrubs in the spring during its larval (caterpillar) stage, is now emerging and beginning to fly. The Maryland Department of Agriculture (MDA) is asking residents to keep their eyes open for the "invader." The moth was first reported in Maryland by an Anne Arundel County homeowner this spring and the MDA is now trying to locate populations of this new invasive species.

"The landscape and nursery industry is Maryland's second largest agricultural industry, with more than $300 million in farm receipts," said Dr. William F. Gimpel, Administrator, MDA's Plant Protection and Weed Management Section. "This new invasive species is not beneficial to the industry or to homeowners who enjoy the popular shrubs this invader likes to eat. Together, we can combat invasive species in Maryland. We count on the eyes of the public to help us find this and other new species so we can learn more about them and protect the agricultural industry."

The adult moths have distinctive clear wings about a 1-inch wide with scattered black markings similar to wasps. The black abdomen has a characteristic orange tuft of hair at the end. The moths emerge in November and are active during the day, with a slow, fluttering flight behavior usually about 3-15 feet above the ground. They lay eggs in clusters on the stems of host plants in November and December.

Citizens Urged to Report Pest of Popular Ornamental Shrub
Eric R. Day, Virginia Polytechnic Institute and State University,

Eggs hatch in March and April and readily drop on a line of silk if disturbed. The colorful larvae are a light greenish-yellow with black, lengthwise stripes. Larvae feed in large groups on the upper and lower surface of host plant leaves, sometimes leaving nothing but stems behind. Although euonymus bushes generally recover from the damage, the temporarily leafless branches are unsightly in the landscape in early to mid-summer. P. sinica larvae enter their pupal resting stage in May and the adult moths start emerging again in November, completing the annual life cycle.

Very little is known about how P. sinica, which is native to Asia, arrived in the United States. It was first discovered last year in Fairfax County, Virginia, where it was reported by a homeowner who noticed the damage. Alerted by Virginia authorities, MDA entomologists were vigilant and quick to identify larvae that were submitted in May, 2003 from the Glen Burnie area. The pest was found to be abundant on euonymus planted throughout the development. In a follow-up survey, feeding damage was found to be quite dramatic in many locations over a 10-square mile area.

As with many invasive species, humans can also help to slow the spread of P. sinica. By alerting the public to this emerging pest, the MDA hopes to further delimit the existing population in Maryland and develop a long-term management plan. In the meantime, Marylanders can help by watching for these day-flying moths in November and December and reporting any suspects to MDA at 410-841-5920.

For more information on this and other invasive species in Maryland, visit the Maryland Invasive Species Council at

Adapted in part from Biology Statement by John Brown, John Brown, May 6, 2003.