A small, stem nesting solitary wasp. Identification keys are given in Lomholdt (1984) (as R. nigrinum), Richards (1980) and Yeo & Corbet (1995).

This species had not been recorded in Britain at the time of Richards' (1980) RES handbook, but identification characters are given in Lomholdt (1984). It was first recorded in Britain in 1986 (Allen, 1987), although it may previously have been confused with S. solskyi.

This is by far the more common species of Stigmus in Britain.

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

Identification keys and general biology are given in Morgan (1984) and Falk (1991). Previously known as C. helleni Linsenmaier, 1959. Kunz (1994) considers C. bicolor Lepeletier, 1805 and C. illigeri to be the same species. Morgan (1984) separates these two names, with C. bicolor only known from Jersey.

A small, ground-nesting red and black solitary wasp. Identification keys are given in Richards (1980), Lomholt (1984) and Yeo & Corbet (1995).

A species closely related to Passaloecus insignis, from which it is separable only with difficulty.

Probably the most common British species of Passaloecus, at least in the south.

In the older literature this species has been placed in the genus Notozus, where it was known as scutellaris or constrictus. Identification keys and general biology are given in Morgan (1984) and Kunz (1994).