Cemonus dentatus PUTON 1871; Cemonus shuckardi MORAWITZ 1864; Pemphredon tenax FOX 1829;
The genus Pemphredon has been the subject of much taxonomic debate regarding the aggregation or splitting of species pairs. This particular species has been subjected to more grammatical than taxonomic uncertainty, with Richards (1980) and Bitsch et al. (2001) referring to it as inornata Say, whilst Lomholdt (1984) opts for inornatus Say.
Richards (1980) considered this species to be common and found throughout England, Wales, southern Scotland and Ireland. Data collated for this atlas suggest that it is rather sparse in Scotland and has a very limited distribution in Ireland, although this may reflect relative lack of recording.
It is widespread in Scandinavia, approaching the Arctic Circle (Lomholdt, 1984) and is found across the Palaearctic to the Far East. It is also found in North America, Canada and Mexico (Bitsch et al. 2001).