Tiny predator is Top Gun of the insect world

A tiny fly, the size of a grain of rice, could be the Top Gun of the insect world after Cambridge scientists identified its remarkable ability to detect and intercept its prey mid-air, as Stuart McDill reports.

CAMBRIDGE, ENGLAND, UK (REUTERS / UNIVERSITY OF CAMBRIDGE) – The eyes of a robber fly or Holcocephala – a tiny predator that, we now know, shows the rest of insect world how it’s done

Identifying its prey, locking on and going in for the kill – regardless of mid air alterations of trajectory.

A team from Cambridge University say the robber fly’s sophisticated compound eye is its secret weapon – with larger lenses in the middle.

“So robber flies are predatory insects, same as dragon flies are, and yet some of the robber flies are only 3mm long and we wanted to know how come they can do this predatory behaviour being so small. Now there are other flies as well that are predatory and we work with them in the lab but their eyes don’t look like robber flies’ eyes so we knew that this species was doing something really special.”

The team used a tiny black bead on a fishing line to tempt the fly into performing for their high speed cameras….

even tricking it with changes of course in mid air.


“We have to leverage a whole bunch of computational power just to analyse all of this and they do it real time. So if the prey, in this case we had times where we would trick the prey. We’d have the bead going across and then we’d have it reverse and the whole time the animal knows exactly where its prey is. It will change its trajectory if the prey changes trajectory to match perfectly.”

A two proton microscope reveals the robber flies’ larger lenses are the same size as those of a dragonfly ten times its size – and thought to have the best vision of all insects.

The researchers believe the fly has evolved a perfect balance of precision vision with minimal data processing —

a combination of abilities that could be useful if applied to the next generation of flying drones.