HYMENOPTERA > APOCRITA | Aculeata > APOIDEA > Halicidae

Unfortunately, these small, attractive, black and red cleptoparasitic bees are so similar to each other in general appearance that it's pretty much impossible to reliably confirm the species from photos. Females can sometimes be distinguished but, in most cases, the males would have to be closely examined and probably dissected.

There are 17 species and, according to the NBN Atlas, most have been recorded locally to me at some point, either in Dorset (VC9) or South Hampshire (VC11). The most frequently observed is Sphecodes ephippius, followed by S.pellucidus, S.monilicornis, S.puncticeps, S.geoffrellus and S.reticulatus.

Sphecodes monilicornis is one of three species with distinct punctures on the top of the head behind the ocelli, which are clearly definable in the following photos - matching the punctures on the thorax and in contrast to the rugose surface in front and at the sides of the ocelli. The other two species are Sphecodes reticulatus and Sphecodes gibbus, but Sphecodes monilicornis can be distinguished by the more box-shaped head with parallel sides that turn more sharply inwards at the back, coupled with a slightly slimmer build, predominantly orange-red abdomen and whitish rather than dark hairs on the hind tibia. I'm pretty sure the identity is correct, but have erred on the side of caution.

The females are mostly seen around the nest holes of their host species, in this case either the Orange-legged Furrow Bee, Halictus rubicundus, or possibly, and more likely at the location where this individual was photographed, one of the common Lasioglossum calceatum group species. 

Sphecodes pellucides is a widespread and common species on sandy heathland sites, especially where its primary host species the Sand Pit Mining Bee, Andrena barbilabris, is present. The females have a particularly broad and transverse head when viewed from above, a densely punctate scutum and rather long whitish hairs on the head and thorax. The two individuals featured below, both photographed at the same location as the previous species, but at different times, are possibly this species, based on their general appearance, habitat and known records for the site. The first individual seen back in August 21 was considered likely by an expert on the UK Bees, Wasps and Ants FB group. The second is more questionable, hence left as unidentified.