Officials warn box tree moths detected in Michigan nurseries, greenhouses

Charles E. Ramirez
The Detroit News

A caterpillar that kills boxwood plants has been found in Michigan, state officials warn.

The box tree moth has been detected for the first time in U.S. nurseries and greenhouses, according to the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service.

A box tree moth caterpillar on a plant.

Michigan's Department of Agriculture and Rural Development said because the insect can cause significant defoliation and death of boxwood trees, it is urging anyone — especially landscapers — who purchased boxwood plants in the last two months to inspect them very closely for the invasive pest.

"Boxwoods are commonly planted in North America as ornamentals with the largest plantings occurring in urban areas," Robin Rosenbaum, plant health section manager of the agriculture department's pesticide and plant pest management division, said in a statement. "In 2014, boxwood made up 15 percent of broadleaf evergreen sales in the United States with an estimated value of $126 million. Ensuring this pest is quickly contained is crucial to protecting the state’s boxwood."

Box tree moth caterpillars are green and yellow with white, yellow, and black stripes and black spots. They feed only on boxwoods, making them easy to spot, officials said.

They also said the adult moth can be found in two forms. The most common has white wings with dark brown borders. The other, a dark form, has solid brown wings with a white streak or spot on each forewing. Both have a white dot or mark in the middle of each forewing.

Signs of infestation include silky webbing and possibly caterpillars located deep inside of the plants, the state's agriculture department said.

People who see signs of box tree wood moths on plants should contact the department's nursery program at and provide contact information, photos, as well as when and where the plants were purchased. They may also contact Michigan State University Diagnostic Services at

Twitter: @CharlesERamirez