This is one of the six British species retained within the family Sphecidae, whilst the remainder of the digger wasps are placed within the Crabronidae. It is closely related to P. hirsuta (Scopoli).

Richards (1980) and other authors separated this species from P. clypealis Thomson, but recently the two species have been synonymised under P. morio. Lomholdt (1984) refers to the two as separate species and places them in a separate genus, Ceratophorus.