What has five eyes, a pair of wings, spiked legs with sharp grasping claws, and a scabbard with a stabbing beak inside? It’s a magnificent predator known as the robber fly! Robber flies (family Asilidae) are a large group of flies found all over the world in and near forests. They are among the most effective and terrifying predators on the planet.
When most people think of scary predators they think of things such as sharks, lions, tigers and wolves, but the robber fly is right up there with them. Like all flies, it has two wings (Diptera, the name for the group containing flies and mosquitoes means 2 wings). The powerful muscles in the enlarged thorax allow the robber fly to be a very strong and rapid flyer. To see where it is going and what it is hunting for, the robber fly uses its 2 large compound eyes, which enable it to see ahead, to the sides and behind all at the same time. A second set of 3 simple eyes on a bump on its ‘forehead’ sees only light, shadow and movement. but helps the fly not to be easily caught or attacked. Six long, spiny legs ending with grasping claws allow the fly to capture and hold prey, often when both fly and prey are in flight.
Invertebrate biologist, curatorial assistant and imaging specialist
Department of Entomology