One of the smallest of a genus of small, predominately black, wasps. It seems to be genuinely scarce throughout its world range, but is very widespread. The female is very similar to that of Crossocerus wesmaeli, which can be abundant on light sands, but the male has a very distinctive peg on the underneath of the 7th antennal segment. For more comment on the separation of females see Edwards (1982).

A medium-sized Ectemnius with well-separated spots on the terga. Previously known as E. chrysostomus (Lepeletier & Brullé, 1835).

The more frequent of the two Ectemnius species with short mesonotal pubescence and a pronotum with spines (subgenus Ectemnius). It has been suggested that E. dives is a relatively recent colonist possibly introduced with timber, as the first British record was in 1926 (Nixon, 1935).

The larger and more frequent of the two British species of Ectemnius with reduced yellow spots on gastral terga 1 and 3 (subgenus Hypocrabro).

One of the more common large Ectemnius species easily identified in both sexes by the densely striate mesoscutum with transverse striae on the front half.

The distribution of this species is significantly different from that published by Richards (1980), due to the separation in Britain of two species, T. nitidus and T. unicolor from the one taxon previously recognised as T. unicolor.

There is considerable confusion regarding the correct use of this name. As interpreted here this is the scarcer species of the two, apparently restricted to IOW and Dorset.

A medium-sized species of Ectemnius.

One of the smaller Ectemnius species, resembling a small E. continuus, but much less frequent.

A large Ectemnius resembling the common E. cavifrons but scarce in most areas. Formerly known under the names nigrifrons (Cresson, 1865) and planifrons (Thomson, 1870).

A large Ectemnius closely resembling the common E. continuus, but considerably scarcer. Formerly known under the names zonatus (Panzer, 1797), saundersi (Perkins, R.C.L., 1899) and quadricinctus (misidentification). The last name was also shared with E. cephalotes, making some old records impossible to assign.