WASHINGTON, D.C. – The USDA announced late last month that an invasive species, the box tree moth, had been found in several states after infested boxwood plants were shipped from a nursery in Ontario, Canada, near Niagara Falls.

The box tree moth can significantly damage and potentially kill boxwood plants if left untreated. According to the announcement, dated May 28, from August 2020 to April, a nursery in St. Catharines, Ontario, shipped boxwood shrubs that may have been infested with box tree moth to locations in six states. That includes 25 retail locations in Connecticut, Massachusetts, Michigan, New York, Ohio, South Carolina and a distribution center in Tennessee. The USDA’s Animal and Plant Health Inspection Service (APHIS) is working with state governments and nurseries to contain and eradicate the pest. The agency has also been working with state officials to determine if more nurseries may have been impacted.

On May 26, APHIS issued an order to halt the importation of boxwood, Euonymus and holly plants into the United States. The boxwood shrub is very commonly used in landscaping and is the plant most commonly infested with box tree moth, a native of East Asia. It was found in the Toronto area of Canada in 2018. The caterpillars, which are green and usually with black markings, can defoliate a host plant. The caterpillars can then go on to feed on bark and possibly destroy the plant.

“We’ve had a few nurseries in Michigan where we have found the pest,” said Robin Rosenbaum, the plant health section manager of the Michigan Department of Agriculture and Rural Development. “We’re asking anyone who’s purchased boxwoods to go and examine them and if they see silky webbing or green caterpillars with a bold black stripe or spots to call us. We need the help of the public right now.”

Rosenbaum said all of the affected nurseries have been very cooperative. Most affected is Wayne County, which includes Detroit and a number of other communities. Rosenbaum is asking that people in this area be especially alert to the possibility of infested plants there.

In Tennessee, infested plants arrived at a distribution center in Memphis, in the southwest corner of the state. “We do have traps set up throughout the state and so far we have not found any box tree moths in those traps,” said Kim Doddridge, a spokeswoman for the Tennessee Department of Agriculture.

According to Dan Kenny, chief of the plant health division at the Ohio Department of Agriculture, two locations in the state received infested boxwoods. “There’s about 800 plants that got into the state, but it’s not as bad as it sounds,” he said. “We haven’t actually found any caterpillars on any shrubs, though there has been some evidence of feeding.” Kenny said it’s his understanding that the nursery in Canada that sold the infested stock is compensating the nurseries that bought the plants.

“This is definitely concerning for nurseries in Ohio,” Kenny said. “These shrubs are pretty important for the nurseries, so we definitely don’t want them getting out.”