Despite being similar in size to a grain of rice, the fleece fly has exceptional visual abilities making it a top predator capable of spotting prey at great distances.
Locating and « locking » a prey at a distance of some 50 centimeters, or about 100 times its size, capturing it in less than half a second, and this, without ever missing its target, that’s what makes a fleece fly (or asilid) a fearsome predator. This is revealed by a team of scientists led by Paloma Gonzalez-Bellido of the University of Cambridge, England, in the journal Current Biology.
The researchers used high-speed cameras to show exactly how the fly positions itself to capture a moving target. In particular, they observed a behavior never before described in a flying animal: about thirty centimeters from its prey, the insect slows down, turns slightly and closes in for a close hold. » This locking phase and this change in flight behavior are quite remarkable. You would expect them to do something very simple, speed up to their prey says Sam Fabian, a Cambridge graduate student and co-author of the study.
It is exceptional visual abilities that allow the fleece fly to be so successful in hunting. » When we think of hunting animals, we think of excellent vision and good speed. But when you’re such a small animal, you have a very small brain and limited sensory abilities. “, explains Paloma Gonzalez-Bellido.
While we only have one lens in each eye, the fleece fly has several thousand of them, of different sizes. In the center of each eye, the researchers found a high density of extremely small sensors that allow it to see its prey from a distance and « lock on » it, can we read in the New York Times. » We knew that asilids had very good eyesight compared to other flies, but we didn’t think they were able to compete with dragonflies, which are ten times larger, in terms of their retina resolution. Likewise, we did not imagine that these flies knew how to target a victim like a fighter jet, although we assumed that they could synchronize their flight with the movements of their prey “, explains Paloma Gonzalez-Bellido.