Hornet Robberfly (Asilus crabroniformis) Š Colin Titcombe & Chris Hatch
Notes on the Hornet Robberfly (Asilus crabroniformis) in Gwent – an update Colin Titcombe & Chris Hatch 1. According to the particular authority concerned, Asilus is either the largest, or one of the largest, Dipterids in Britain. 2. Asilus is a declining species in most of its western European haunts, including those of the British Isles. 3. One of the greatest threats to the ongoing presence of Asilus, and other insects of the dung-inhabiting community, is said to be certain veterinary products used to dose farm livestock (avermectins). 4. During the course of its predatory activities toxic injection stills all resistance at the time that the piercing mouthparts enter the prey. 5. Members of the Dipterid family Milichiidae, such as the tiny Desmometopa, live on the bodies of some spiders and predatory insects such as Asilus in the role of a commensal, and partake of a free meal when the predator makes a kill. 6. Information on the larval food of Asilus varies from one authority to another. Are they predatory or are they general scavengers? It seems we still do not know!
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