The damselfly (Zygoptera) are a suborder of the order Odonata commonly known as horses devil or also called Galactic for their metallic colors. Their way of hunting is as follows: they fly like a helicopter and, suddenly, they lunge towards their prey at high speed.
They should not be confused with dragonflies, although they look very similar in appearance. A new study also suggests that they come from the same ancestor and that now their hunting strategies have diverged .
Predators
New research shows that these two predators share something deeper than their appearance. In a study published recently in Current Biology , González-Bellido and his colleagues reveal that the neural systems behind the vision of damselflies and dragonflies have a common ancestor that lived before dinosaurs. But over the millennia, this brain wiring has adapted in different ways in each creature, allowing for radically different hunting strategies .
For flying creatures, quick and accurate vision is crucial for survival. Recent research suggests that faster-flying raptors also see changes in their field of vision more quickly, demonstrating the link between wing speed and brain speed .
The order of insects from which damselflies and dragonflies are derived already flew before birds, and their vision is faster than that of any vertebrate studied so far.
To hunt, records made by González-Bellido show that dragonflies rise in a straight line to capture unsuspecting insects from below, almost as if their prey had stepped on a landmine. In this way, dragonflies catch their prey 97 percent of the time .
But if dragonflies hunt slightly differently than damselflies, it seems that it is simply because of the location of the eyes. Damselfly eyes are on either side of the head, looking straight ahead. The eyes of these dragonflies are on the top of the head, and the visual neurons appear to guide the wing muscles as if they had only one eye.
To take a closer look at the neurons that link vision and flight, the researchers equipped the wings of these insects with sensors and showed them a video of a moving point . They discovered that the wings of damselflies see what is right in front of them, while the vision of dragonflies is more clearly concentrated just above them.
The most distinctive difference appeared when the researchers blocked the view of either eye on a jewel wing using a black patch. If either eye was covered, certain neurons shut down. These neurons received messages from both eyes .
Dragonflies hunt outdoors, in sunlight, where precision is key. The ponies hunt in the shadows cast by plants and trees, where using the vision of two separate eyes to avoid obstacles may be more important.
That is, their shared neural system, which comes from a common ancestor and may be more than 250 million years old, was flexible enough to adapt to the needs of a variety of creatures in different times and environments .