Pachybrachis nigricornis, (Say)

Barney, Robert J., 2019, Key to All Sixty-Four Species of Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae) in the Eastern USA, The Coleopterists Bulletin 73 (1), pp. 85-96 : 87

12 ʹ. Elytra appearing black with subsutural vitta and margin yellow, each elytron with 2 discal vittae (often reduced or broken) and the suture black; pronotum yellow with moderate to broad, sharply defined, black “M,” lateral vittae rarely disconnected from median vitta; aedeagal beard short and fine, extending from widest point of median lobe to terminus .... ............. 38. P. nigricornis (Say) (in part)