Dragonfly- YG

The dragonfly is an insect: belonging to the order Odonta and suborder Anisoptera. They are long and streamlined in shape, holding their wings horizontally at flight and at rest. They are often brightly-colored and iridescent. Their diet primarily consists of smaller insects such as butterflies, moths, beetles and flies. They also have specially adapted eyes- they are known as multi-faceted or compound eyes that enable the insects to see in all directions at the same time. They also have specialized physiological and behavioural adaptations for thermoregulation- including color change, the obelisk position and wing whirring.

Cooling Off

Dragonflies may overheat from time-to-time, which is dangerous for the organism. To prevent over-heating, dragonflies have developed a mechanism known as the 'obelisk disk', where they will raise their abdomen vertically into the air; reducing the surface area exposed to the sun. They can also lower their abdomen, even as they fly, also to reduce surface area exposed to the surroundings.

Warming Up

To warm up, dragonflies will often bask in the sunlight as many other ectotherms do- for example, iguanas, snakes and turtles. Some dragonflies even have translucent abdomens and dark wing patches at the base of their wings. This is to absorb sunlight and channel heat to their organs and wing muscles so that they raise their body temperature. Dragonflies can also vibrate their wings, known as 'wing-whirring'. This is similar to shivering in mammals, the contraction of the wing muscles generate enough heat for the dragonfly to be able to fly. Some species of dragonfly are even able to change color according to their body temperature. For example, when Common Green Darners overheat, their abdomens turn a bright blue color, reflecting light as a result of the light-colored platelets in their blood rise to the surface. When their body temperature drops too low, their abdomens subsequently turn a rich purple, black and brick red- absorbing light and allowing the dragonflies to warm up.