HYMENOPTERA > APOCRITA | Aculeata > Crabronidae > Crabroninae

Three rather similar Oxybelus species occur in Britain; one being widespread across England and South Wales, and two which are much more localised and listed as nationally scarce. They are rather small (5-9mm body length) active wasps with a predominately black body with pale markings on the abdomen.

Oxybelus uniglumis is by far the most common of the three species. It can be seen from June to September on open heathland or similar habitats where there is suitable loose sand for its burrows, and occasionally where there are heavier soils such as in woodland clearings. The female of the species prefers to dig her burrows into flat or gently sloping surfaces. Subject to the compactness of the soil the nests can be from as little as 20mm to as much as 120mm deep and can take up to two hours to dig. The entrance to the burrow is covered when she goes hunting to lessen the opportunity of cleptoparasitic Miltogrammine flies (Senotainia conica and two Metopia species) entering and laying their eggs onto the wasp’s provisions. Oxybelus uniglumis catches its Dipteran prey either on vegetation or in flight and immediately paralyses it with a sting so that it can be carried back safely. It often impales the fly on its sting, which is unusual in solitary wasps. They drop the fly close to the burrow so that it can be opened and quickly inspected before carrying the prey in. The process continues until each nest cell is provisioned with a suitable stock, which could be anything from two to sixteen flies, dependent on their size. As soon as there are sufficient flies in a cell, the wasp oviposits on them, and then goes on to provision the next cell. There are usually two or three cells in a nest burrow.