Top-horned Hunchback - Acrocera orbiculus

Acrocera orbiculus is one of three British Acroceridae species. They are small, dumpy flies with a strongly domed thorax, relatively small head and large squamae. Acrocera orbiculus is easily distinguished from the other two acrocerids by the fact that the antennae are placed high on the head directly in front of the ocelli (the bristle-like aristae giving away their position). The abdomen can be extensively cream-coloured or mostly black.

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It can be found in a variety of habitats, including chalk grassland, heathland, woodland edge, wetlands, coastal dunes and saltmarsh edge.

Adults are recorded from May until September with peaks in July and August.

The larvae develop as internal parasitoids of spiders. Eggs are laid on vegetation and the larvae then attach themselves to passing spiders.

This is the most widespread and frequent acrocerid though it is, nevertheless, rather scarce and localised in Britain.

Rare in Leicestershire and Rutland.