Michigan Expands Quarantine to Combat Box Tree Moth

By Andi Anderson

Michigan's Department of Agriculture and Rural Development (MDARD) has amplified the state's interior box tree moth (Cydalima perspectalis) quarantine, effective from December 11, 2023. Although not a direct hazard to Michigan's ecosystem, this invasive species poses a severe risk to ornamental boxwood by causing substantial defoliation and even plant death.

Expanding the quarantined area encompasses entire counties including Clinton, Eaton, Ingham, Jackson, Lenawee, Livingston, Macomb, Monroe, Oakland, St. Clair, Washtenaw, and Wayne. This comprehensive measure prohibits the movement of all Buxus genus plant parts, living or dead, outside the quarantined area. However, holiday greenery like wreaths, boughs, and grave blankets are exempt if transported between October 15 and January 1.

Mike Philip, MDARD's Bureau Director of Environment and Sustainability, emphasizes the importance of this expansion to curb the spread of the box tree moth while minimizing its impact on Michigan's horticulture industry. The agency collaborates closely with the industry to ensure safe plant material trade and minimize disruption to nurseries, greenhouses, and retailers within and beyond the quarantine area.

Recognizable by their green and yellow striped appearance, box tree moth caterpillars hide within foliage during early infestation stages. Signs include leaf damage, yellowing, webbing, and excrement around the plant, leading to defoliation and potential plant demise.

Residents within the quarantine zone are urged to inspect their boxwood for signs of infestation, reporting suspected cases via www.Michigan.gov/ReportBTM to aid in containment efforts.

Upon confirmation, affected individuals should prune infested branches or, for severe cases, remove the entire boxwood plant and dispose of the debris securely. Visit the Michigan State University Insecticide Options for Box Tree Moth Management for effective insecticide recommendations.

For further details on the box tree moth quarantine and additional information, visit www.Michigan.gov/invasives.

Photo Credit: pexels-nataliya-vaitkevich