Watch the weird aerodynamics behind mosquito flight

Mosquitoes are strange fliers. Compared with other insects, birds, and bats, their shorter wing strokes and oddly long—and skinny—wings have made scientists wonder how they can get off the ground at all. Now, a new study shows how these animals get their lift: with help from a clever rotation of their wings. Most animals generate lift, the force that keeps them aloft, during the downstroke of each wing beat. This creates a vortex of swirling air over the wing’s leading edge, which lowers the pressure above the wing and pushes the animal up. But the mosquitoes supplement this leading edge lift with a little something extra. To find out what it was, scientists recorded high-speed video of the southern house mosquito (Culex quinquefasciatus) and modeled its flight aerodynamics. They found that mosquitoes rotate their wings at the end of each upstroke and downstroke, which generates lift along the entire length (and explains why long wings are useful). The rotation also helps them harness the wind from their previous wing beat, they report today in Nature. When the wing reverses direction, the air that rushed over it during the previous stroke forms a second vortex at the back of the wing. The mosquitoes angle their wings to take advantage of this trailing edge vortex (red spirals at the rear of the wing in the above video) to generate lift in a process known as “wake capture.” Although the new aerodynamics have been shown only in mosquitoes so far, the scientists say the same principles could be at play in other insects, especially those with long, slender wings and short, rapid wing beats.