Pemphredon rugifera (mis-spelling); P. wesmaeli (Morawitz, 1864); P. mortifer Valkeila 1972.
Following on from the general comments about the difficulty in recognising the species within Pemphredon on physical characters, which is detailed in the account for P. lethifer, the name P. rugifer is similarly bedevilled with supposedly different entities (including one incarnation of P. lethifer!). Within the span of modern recording Richards, 1980, provides two names, P. wesmaeli and P. mortifer for the fauna of the British Isles and Ireland, these being separated by a supposed northern and southern distribution- identification often being influenced by whether the recorder considered the location to be northern (?Yorkshire) or southern. Maps based on these names showed a pleasing, if self-referential, distributional split. Examination of the specimens, without the locality information, failed to support this. Dollfuss, 1991 Bestimmungsschlussel der Grabwaspen Nord- und Zentraleuropas (Hymenoptera, Sphecidae), Stapfia 24, synonomysed both these names with P. rugifer (but as rugifera - that arcane Latin agreement issue again).