M. eupeus can reach a size of 4 to 5 centimetres (1.6 to 2.0 in) in length. The entire body is yellow to yellowish brown. The dorsal segments (tergites) of the mesosoma often have longitudinal irregular stripes that are black to dark brown.[3] They exhibit sexual dimorphism, the adult females being generally larger than males but have a lower number of pectinal teeth (16 to 23, as opposed to 22 to 28 in males).[4]