The United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) has identified the boxwood moth (Cydalima perspectalis) in nurseries and greenhouses in the United States, including Michigan. This is the first detection of this invasive species in the country. The boxwood moth is not considered a forest pest because boxwood is not native to the forests of Michigan. However, if left unchecked, it could cause extensive defoliation and death of boxwood in the landscape.
The Michigan Department of Agriculture and Rural Development (MDARD) advises anyone, including landscapers, who have purchased boxwood plants in the past two months to inspect their plants very closely for the invasive pest. Signs of infestation include silky straps and possibly caterpillars located deep inside plants.
Boxwood moth caterpillars are green and yellow with white, yellow and black stripes and black spots. The caterpillars feed only on boxwood, which makes them easy to spot. The adult boxwood moth has two color forms. The most common form has white wings with dark brown borders, while the dark form has solid brown wings with a white streak or spot on each forewing. Both shapes have a distinctive white dot or mark in the middle of each fore wing.
“Boxwood is widely planted in North America as an ornamental, with the largest plantations found in urban areas. In 2014, boxwood accounted for 15 percent of evergreen hardwood sales in the United States with an estimated value of $ 126 million, ”said Robin Rosenbaum, director of the Plant Health section of the Pest Control Division. MDARD pesticides and plant pests. “Ensuring that this pest is quickly contained is essential to protect the state boxwood.”
To further prevent the introduction of box moth into the United States, USDA APHIS issued a federal order on May 26, 2021, banning the importation of all boxwood (Buxus spp.), euonymus (Euonymus spp.) and holly (Holm oak spp.) plants for planting from Canada.
If you see any signs of boxwood moth on your boxwood plants, contact the MDARD Nursery Program at [email protected] with your contact details, photos, and when and where you bought the factory. You can also contact Michigan State University Diagnostic Services at [email protected].
For more information on MDARD’s Pesticide and Plant Pesticide Management Division, visit Michigan.gov/MDARD.