Identification key and general biology are given in Morgan (1984). The only entirely metallic blue wasp in Britain.

A small black solitary wasp nesting in cavities in dead timber. Identification keys are given in Yeo & Corbet (1995), Lomholdt (1984) and Richards (1980). In older literature this species was referred to as Crabro carbonarius (Dahlbom), with the name C. leucostomus or C. leucostomoides being applied to the much more common Crossocerus megacephalus, so care is needed when citing older records of this wasp.

Identification key and general biology are given in Morgan (1984). Previously this species was misidentified as H. amoenula and is also known as H. generosa (Förster, 1853) in Kunz (1994).

A small black solitary wasp about which very little is known. Identification keys are given in Yeo & Corbet (1995), Lomholdt (1984) and Richards (1980).

Description and notes A medium-sized red and black spider wasp. Identification may be made from Day (1988). The male has a relatively distinct genital plate, but females are very similar to others in the subgenus Ammosphex Wilcke, and considerable care is necessary in identification.

Identification key and general biology are given in Morgan (1984). Kunz (1994) considers C. bicolor and C. illigeri (Wesmael 1839) to be the same species. Morgan (1984), however, separates these two names.

There are approximately 100 species in this genus worldwide. Lomholdt (1984) states that there are only seven species in Europe, but Bitsch et al. (2001) list ten, although one of these, P. hidalgo, was only described in 1990.Three species have been recorded in Britain.

Identification keys are given in Morgan (1984). General biology is given in Morgan (1984) and Falk (1991).