HYMENOPTERA > APOCRITA | Parasitica > Chalcidoidea > Chalcididae

The CHALCIDOIDEA superfamily includes a large number of species that are collectively referred to as chalcids or chalcid wasps. They are taxonomically separated into sixteen families of varying size. The Chalcididae is one of the smaller families which, until recently, only had eight recognised British species. The latest checklist however, now includes ten species in six genera, in two subfamilies;

Chalcidinae - Brachymeria (3), Chalcis (3) and Conura (1)

Haltichellinae - Haltichella (1), Neochalcis (1) and Psilochalcis (1)

Although the group name chalcids is similar, the species in this family are known as Chalcidid wasps.

Presumably as a result of their life cycle and small size, adults seem to be rarely seen or photographed. The most frequently recorded species according to the NBN Atlas at the time of this update are Brachymeria minuta (60), Chalcis sispes (50) and Haltichella rufipes (25).

Whilst their appearance and size vary, they can generally be recognised by their swollen hind femora and bent hind tibiae. The three Brachymeria species can initially be distinguished from the other members of the subfamily by the close connection between the thorax and gaster, whereas in Chalcis and Conura there's a distinct petiole. Haltichella rufipes can be identified by a combination of features relating to the structure of the head, body and legs, location of the antennae, and wing venation.

Brachymeria tibialis is a small (3-5mm body length) robust, black bodied, mainly yellow-legged species with characteristic greatly swollen hind femora and distinctly curved tibiae. Adults may be seen in grassland areas where Burnet Moths (Zygaena) occur, as it's the larvae of these species in which the female wasps inject their eggs. Brachymeria tibialis was only added to the British List in 2008 and, to date, has only been officially recorded from six locations despite the fact that it's probably quite widespread across most southern areas.

Despite its name, Bracymeria minuta is a larger species (5-6mm body length) with a raised thorax and a more elongate gaster that's pointed towards the tip rather than rounded. The antennae have a different structure with the third segment onwards being more-or-less spindle shaped, tapering at both ends, whereas in Brachymeria tibialis those segments are pretty much of uniform thickness.

Updated, March 25 (v.2)