Prionoxystus robiniae, the carpenterworm moth or locust borer, is a moth of the family Cossidae. It was first described by Peck in 1818 and it is found in southern Canada and most of the United States.
The wingspan is . Adults are on wing from May to July depending on the location.
The larvae feed on locust, oak, chestnut, poplar, willow, maple and ash. The species is considered a pest, because the tunnels the larvae create decrease the value of hardwood lumber.