Locust Borer (Megacyllene robiniae) 2016-9-27 Newark, DE

The Locust Borer is what's known as a "long-horned beetle". The larvae tunnel through Black Locust trees and for a brief time in autumn the adults come out and feed on pollen, preferably Goldenrod. If you want to see one of the colorful beetles go visit a Goldenrod patch near a Black Locust tree in the fall, because that's when Goldenrod is in bloom.
http://bugguide.net/node/view/436