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How dragonflies flip over in flight using ultrafast wing movements

When dropped upside down, dragonflies rapidly flip 180 degrees by changing the angle of their wings – but only if they can see their surroundings Life 12 May 2022 By Corryn Wetzel Dragonflies use a combination of visual cues and precise control of their wing pitch to perform aerial acrobatics. The four-winged insects can rapidly…

When dropped upside down, dragonflies rapidly flip 180 degrees by changing the angle of their wings – but only if they can see their surroundings



Life



12 May 2022

By Corryn Wetzel

Dragonflies use visual cues as well as precise control over their wing pitch in order to perform aerial acrobatics.

The four-winged insects are able to quickly correct themselves when they find themselves upside down. However, until now researchers were unsure how they did it. Jane Wang ,, a Cornell University researcher who studies the physics and biology of living organisms, noticed this unusual behaviour eight years ago. Surprised, a dragonfly flipped itself when she dropped it headfirst.

Wang and her colleagues devised a series experiments to discover how the insects did it. They first painted white dots onto the wings and bodies seven dragonflies. They then released the insects upside-down and captured their movements with a high speed video camera. To get a better view of the precise angles of the wings, they slowed the footage and created a 3-D model of the dragonflies moving using a computer algorithm.

The digital simulation revealed what Wang’s eyes couldn’t see: the dragonflies were pitching their right and left wings at different angles to flip over in just 200 milliseconds.

dragonfly migrant hawker (Aeshna mixta) in flight; Shutterstock ID 1891950238; purchase_order: -; job: -; client: -; other: -

A dragonfly (Aeshna mixta) in flight

Shutterstock / Petr Ganaj

“When they beat their wings [dragonflies], they are constantly changing the pitch.” says Wang. “Now, they must create a difference between left and right wings – just a little .”

Some Dragonflies rolled to their right, while others went left. The insects used an identical asymmetrical angle of their wings to flip in midair.

The experiment showed the physical mechanism behind the lightning-fast rotation of the dragonflies, but did not reveal how they sensed they were upside down. Drawing on previous research, Wang says she suspected they might be using visual input from their large, multi-lens eyes, or from light-sensitive organs called ocelli on top of their head.

The team blocked the eyes and ocelli of the dragonflies with opaque black paint and released them upside-down. They couldn’t get right this time. Wang says, “Sometimes they didn’t flap their wings at any,”

The researchers concluded that visual signals must help the insects orient themselves in space, which

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