Robber Fly

Robber Flies, sometimes called Assassin Flies, belong to the Asilidae family of insects and there are many species. They are large, bristly flies (flies have just one pair of functioning wings) that are fearsome predators of other insects which they mostly capture in flight. They also prey on spiders and ants. Most Robber Fly species are distinguished by their robust build, large eyes, and a hairy ‘moustache’.

Robber Flies inhabit urban parks and gardens, woodlands, and forests – wherever there are other insects and spiders to feed on.

They capture their prey with their hairy legs and strong claws. They use their large proboscis to inject the victim with a toxin and an enzyme that dissolves its innards. After ingesting the meal, there is only the exoskeleton of the prey left behind.

Because Robber Flies often take leaf-eating and sap-sucking insects for prey, they help keep populations of these pest species under control. Some references suggest they can bite us humans if they are mishandled, but they do not seek us out like blowflies and mosquitoes.