Length: 11-26 mm
Megacyllene robiniae is a large and strikingly marked longhorn. The elytra are velvety black with bold yellow markings. The antennae are brown and the legs reddish. The head has three pubescent yellow bands, while the pronotum has four and the elytra have seven (some of them forming zig-zags). The yellow markings on each elytron meet across the suture.
The larvae of Megacyllene robiniae feed on black locust, a fact that has allowed this species to expand its range markedly as humans have planted black locust in new areas. Adults typically feed on the flowers of goldenrod, so this is a late summer species, as far as observing the adults.
Left: Megacyllene robiniae is most often found on goldenrod flowers. This beetle, though, with many others of its kind, was feeding on mint flowers in the shadow of Seneca Rocks in Pendleton County.
A note about our maps