Insect - Locust Borer

The goldenrod is starting to bloom and insects of all types are drawn to it. While walking in the fields behind our house, I came across this Locust Borer (Megacyllene robiniae). The borer attacks only black locust (Robinia pseudoacacia L.) and its hybrids. The honey locust (Gleditsia triacanthos L.) is not affected.



The Locust Borer adult beetles emerge late August to September and feed on goldenrod. The adults will lay eggs in locust trees in the fall. The larvae will hibernating through the winter under the bark and tunnel into trees in spring. They pupate late July/early August and when the adults emerge, the cycle starts again.