The invasive longhorned beetle (Anoplophora glabripennis) has not been detected in Michigan but is in neighboring states including Ohio. This species can easily spread if infested firewood is brought in from Ohio. This beetle is showy and large. Not including its antennas, it is between ¾ to 1.25 inches and has glossy black wing covers with white spots. Their antennas are black and white striped. You will only find adults between late spring and the first frost in the fall. Egg sites can be found year-round. Egg sites are chewed depressions in the tree bark where the female lays the eggs. The eggs resemble a grain of rice.
Once eggs hatch, the larvae eat its way into the tree. They get their nutrients from eating the vascular tissue of the tree. Large amounts of larvae can girdle the tree and kill it. Once the larvae mature, the adults emerge through a perfectly round exit hole on the tree. If a pencil eraser fits into the hole, it is likely from this species. Typical host trees are ash and elm species, maples, and willows.
Ohio State University has a great resource for identifying this species, the damage, and common look alikes.
Have you seen this species? Report it to us or on the MISIN website or smartphone app! Please include a photo to help ID verification.
Environmental Impacts
Invasive longhorned beetles can kill individual trees and entire forest stands if the populations are dense enough. This can cause widespread damage to the ecological balance of our natural forests in Oakland County. Not only would native species diversity decrease but invasive plant species would invade the effected areas.
Treatments
Once trees are infested with Invasive longhorned beetles there is no treatment to save the tree. Infested trees need to be cut down and chipped to prevent the spread. Furthermore, nearby susceptible trees must also be removed. The best treatment for Invasive longhorned beetles is prevention. Do not move firewood without inspecting it first.
Resources
The Invasive Species Centre of Canada has a great fact sheet with quick information on this species.
Oakland County CISMA’s brochure on common forest pest