Locust Borer

Today's insect pest is one you may not physically see very often in its larval stage. One of our ISA Certified Arborists brought this into the office, so I took a picture to share with you. This is a locust borer. (Locust borers are a type of longhorned beetle.) The larval stage tunnels in the wood of black locust trees (and any cultivars). You can see the tunnels created in the wood by the larva as it feeds. (This is a cross-section of a branch removed from a globe locust).

This larva is almost mature; it should pupate soon. If it was still inside the tree, it would emerge as an adult beetle. Adults are black with yellow stripes. They feed on pollen (specifically goldenrod pollen). Females then deposit eggs in the bark of the tree. The eggs hatch and the new larva bore into the inner wood to spend the winter. In the spring, the larva will bore further into the tree and the cycle will repeat itself.

An expert tree company, like Ryan Lawn & Tree, can protect your locusts by applying plant protection products to prevent the new larva from entering susceptible trees before the winter season.