Gasteruption jaculator


Length 10 to 18 mm. The head and thorax are black. The abdomen which is broader at the posterior end is black with a broad orange band. A striking feature of the Gasteruption jaculator is the upright position of the abdomen in flight. In resting position, the abdomen is pulled in a slight downward or upward curve. The wings are then folded along its length. The femurs of Gasteruption jaculator are thick at the end like clubs.

Similar Species

There are several very similar Gasteruption species

Identification difficulty

Gardens and meadows where it can be seen visiting various flowers, or hovering around the nests of solitary bees and wasps.

When to see it

May to September

Life History

The female will visit the nests of various solitary bees or wasps, and will push her ovipositor into the nest, depositing her own eggs on or near to the eggs of the host, on hatching they will feed on the grubs of the host as well as on stored food.

UK Status

Fairly widespread in England but less well recorded elsewhere in Britain.

VC55 Status

Occasional in Leicestershire and Rutland.

Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map