This small great flier of about 4 centimeters in length seems to be the animal capable of flying the longest distances, to the point of covering thousands of kilometers to go from one continent to another.
Scientists at Rutgers University-Newark have based their work (published in the journal Plos One ) on genetic analysis . When studying the populations of this dragonfly in places as far apart as Texas, eastern Canada, Japan, South Korea, India and South America, they found that the great similarity of their genetic profiles had only one explanation: the insects cover enormous distances for their small size, they mate in distant places and create a global genetic base that would be impossible if they did not mix .
As the biologist Jessica Ware, one of those responsible for the research, explains, “if the North American Screen only crossed with the North American Screen , and the Japan Screen only crossed with the Japan Screen , we would have seen genetic differences between some and others. But since this is not the case, there must be a mixture of genes over vast distances ”.
And how does this dragonfly manage to complete its transatlantic flights? The key is in its evolution. Ware indicates that “the surface of their wings has increased in size for the wind to propel them. They flap their wings a lot and then glide for long periods, which saves them a lot of energy. “
Scientists have documented migrations of this insect between India and Africa, jumps that require crossing the Indian Ocean . Dragonflies need a humid climate to breed, which is why they leave India when the dry season arrives.
The strongest specimens can make the trip in one go , even taking advantage of hurricane-force winds; Others stop along the way on islands where they mate, which the next generation – developed in a few weeks – will use as a take-off base to continue the long expansive path of their species.
Image (Greg Lasley): The body and wings of the dragonfly Pantala flavescens have evolved so that the insect can cover long distances gliding with the help of air currents.
