The landscapes around us are a hunting ground for some of the most efficient killers known to science.
Insect predators come in a wide range of shapes, sizes and even motivations. Adult wasps, for example, hunt in order to feed their young and rely on nectar for personal sustenance. While impressive in their own right, there is a backyard predator that is far older than wasps – a flying terror that hunts and eats other insects in every stage of its life.
Despite their attractive appearance, dragonflies are murder machines for any nearby flying insects. Dragonflies are more nimble than a Cirque du Soleil feature – able to react to nearby prey around six times faster than the blink of an eye. They are able to estimate the flight path of any unlucky mosquito, fly, butterfly, bee, or other similar target and attack with a success rate of over 90 percent.
Most can fly around 35 mph, keeping them to the ‘patriotic speed limit’ set by some states during World War II in order to help preserve fuel and rubber. Dragonflies achieve high speeds using two sets of wings that they can control independently. This gives them the ability to hover and fly in any direction desired. As they follow their target, these backyard mavericks can pull around 9 Gs, equivalent to forces that only the finest human fighter pilots handle.
Dragonflies are constantly hunting, eating almost 25 percent of their body weight in insects each day. They can usually be found near the waterways in which they spend the majority of their lives.
Dragonflies are only alive in their fast flying adult forms for a ravenous few weeks. For the vast majority of their lives, dragonflies live underwater as smaller, aquatic forms. This can be anywhere from several months to a few years. During this time, they hunt anything they can catch including mosquito larvae, tadpoles and even small fish.
Their cousins, the damselflies, also share similar life cycles. Damselflies are basically slimmed down dragonflies that give up sheer speed for added agility. While both are hungry predators in their young aquatic and adult hovering forms, they differ in the way their young breathe oxygen and in how they hold their wings as adults. Generally, damselflies carry their wings together over their body when landed, where dragonflies hold their wings apart.
Another difference is their eyes. Dragonfly eyes take up pretty much the entire head and come together in front, whereas damselfly eyes have a space in between. Despite these small differences, the eyes of both species play a huge role in their ability to hunt the rapidly fleeing insects around them.
The vast majority of a dragonfly’s brain is used to process the information it receives from its eyes. It is quite a bit of information indeed – each eye is composed of tens of thousands of different lenses pointing in various directions. This allows the insect to see everything in its frontal hemisphere in a collage consisting of thousands of overlapping images.
The incredibly rapid response time of dragonflies is currently being studied in order to create more robust guidance systems for missile defense systems, and dragonflies are widely used by scientists as indicators of the relative health of aquatic environments.
Each species has very unique requirements for the waterways in which their young grow up – some require stagnant water, while others prefer flowing water. A few even require certain plants growing in specific areas in order to lay their eggs. Fostering populations of these ancient hunters in your area includes leaving any natural waterways untouched, while planting native aquatic plants in man-made water features whenever possible.
Brannen Basham and his wife, Jill Jacobs, operate Spriggly’s Beescaping, a business dedicated to the preservation of pollinators. He can be reached at email@example.com.