A large, robust species with ivory spots on the gaster. Until recently this was the only member of this worldwide genus to be found in Britain, but the recent discovery of Episyron gallicum (Tournier) has complicated matters. Females are readily distinguished by having four comb spines of the fore tarsus (three in gallicum), but males are very similar and require critical examination.

Identification keys and general biology are given in Richards (1980), Gauld & Bolton (1988) and Yeo & Corbet (1995). Females are wingless, but males are fully-winged.

British specimens of the wingless females have black heads, whereas, in Ireland and the Isle of Man, the females have red heads (Stelfox, 1933;Yarrow, 1954a). All males are winged and have black heads. Identification keys are given by Richards (1980) and Yeo & Corbet (1995).

Previously Methocha ichneumonides (Latreille,1805) Identification keys and general biology are given in Champion & Champion (1914), Richards (1980), Gauld & Bolton (1988) and Yeo & Corbet (1995). Females are wingless, but males are fully winged.

Spooner (1973) introduced this species to the British list giving characters to separate it from Ancistrocerus parietum (Linnaeus) and A. gazella (Panzer). Identification keys and general biology are given in Nielsen (1932), Spradbery (1973), Felton (unpublished), Richards (1980) and Yeo & Corbet (1995).

Yarrow (1954b) introduced this species to the British list giving characters by which it can be separated from A. parietum. Identification keys and general biology are given in Nielsen (1932), Spradbery (1973), Felton (unpublished), Richards (1980) and Yeo & Corbet (1995).

Previously known as Ancistrocerus pictus (Curtis, 1826). A colour form with very pale yellow to ivory-white tergal bands is found in Ireland and the Outer Hebrides: elsewhere the bands are bright yellow. Identification keys and general biology are given in Bignell (1881, 1882), Nielsen (1932), Spradbery (1973), Richards (1980), Gusenleitner (1995) and Yeo & Corbet (1995).

Identification keys and general biology are given in Nielsen (1932), Spradbery (1973), Richards (1980) and Yeo & Corbet (1995).

Identification keys and general biology are given in Nielsen (1932), Spradbery (1973), Felton (unpublished), Richards (1980) and Yeo & Corbet (1995).

Previously known as A. albotricinctus (Zetterstedt, 1838) and sometimes misidentified as A. trimarginatus (Zetterstedt, 1838). A colour form in Ireland and the Scottish Isles has ivory white tergal bands; elsewhere the bands are bright yellow. Identification keys and general biology are given in Julliard (1950), Blüthgen (1961), Spradbery (1973), Richards (1980) and Yeo & Corbet (1995).