The only representative of its genus in Britain, this species has always been regarded as a rarity, from its discovery in Britain in 1868 to the present day (Archer 2000). It is targeted for action under English Nature's Species Recovery Programme (Edwards & Roberts 1995; Roberts 1996, 1997, 1998, 1999; Roberts & Else 1997).

Identification keys and general biology are given in Bristowe (1948), Danks (1971), Spradbery (1973), Richards (1980), Yeo & Corbet (1995) and Archer (2000).

Identification keys and general biology are given in Krombein (1967), Spradbery (1973), Richards (1980), Yeo & Corbet (1995) and Archer (2000).

Previously known as Ancistrocerus callosus (Thomson, 1870). Identification keys and general biology are given in Nielsen (1932), Spradbery (1973), Richards (1980), Yeo & Corbet (1995) and Archer (2000).

Identification keys and general biology of the Red Wasp are given in Spradbery (1973), Archer (1979, 1996, 1997a, 19976b), Edwards (1980), Akre et al. (1981) and Else (1994).

A scarce yellow-marked Crossocerus, closely resembling the relatively frequent C. dimidiatus, but typically with entirely yellow tibiae. This species has been variously assigned to the genera Crabro and Cuphopterus in older literature.

A small red and black wasp which is a cleptoparasite of the similar looking Harpactus tumidus (Panzer), occurring in the same sparsely-vegetated sandy areas as its host.

This large and readily identifiable pompilid would not be easily overlooked and is now probably extinct in mainland Britain. The species is, however, still recorded in the Channel Islands.