The amazing bug snatcher
Whether underwater or in the air, dragonflies are amazing creatures in your neighbourhood OUR CHANGING SEASONS
Imagine this. An underwater, jet propelled, jaw thrusting bug snatcher. Sounds like something straight out of a science fiction movie, right? But take a visit to a nearby pond and search through the ooze and among the underwater plants and likely you’ll find one. What is it? Why, a baby dragonfly, of course! Believe it or not, dragonflies spend most of their life underwater. Some species will live up to four years in the nymph or larval stage. Just like the adults, baby dragonflies are remarkable predators. Nymphs will crawl about in soft mud searching for prey. But they hunt through open water as well.
By sucking water in through their mouth and by expelling it out of their rear end, dragonfly nymphs will shoot forward in order to grab their food - just like a jet fighter. They have a lower jaw called a labium that can unfold and extend outward. At the end of this folding jaw are a formidable set of pincers, perfect for clamping down on any wriggling prey.
Dragonfly nymphs catch small underwater bugs, small tadpoles and even minnows! Baby dragonflies need to breathe underwater. That is why they have gills along the rear of their abdomen. By squeezing their abdomen in and out, they can extract oxygen from the surrounding water.
Dragonflies slowly grow and at each stage they shed their skin or exoskeletons. In the final stage, the nymph will crawl out of the water up onto a cattail or nearby branch and split out of its skeleton, along the thorax. It may take as long as two hours for the transformation from nymph to adult to take place. Sometimes you’ll find these empty skeleton cases along the edge of a pond. These are wonderful treasures for kids to keep – called exuviae, they are an exact replica of the nymph and you can store for them for years.
Adult dragonflies are acrobatic and agile predators. They are the kind of insect you want around when there are lots of mosquitoes buzzing about your ears! A single dragonfly can eat 30 to 100 mosquitoes per day. And talk about quick fliers! A dragonfly can zip forward at speeds of almost 50 kilometres per hour, faster than Usain Bolt can run. They can fly straight up and down, hover, move sideways and even fly backwards. Dragonflies catch their prey inside their legs and special spines prevent the insect from struggling free.
If you want to see something wondrous, take a close look at a dragonfly’s eyes. With between 20,000 to 30,000 individual lenses in each eye, dragonflies have incredible vision. They can detect movement up, down, to the side and even behind them! The newest studies suggest that dragonflies can see with souped-up colour vision. Humans see tri-chromatically thanks to three different proteins in our eyes called opsins. We view the world in a mixture of red, blue and green. Some dragonfly species can see up to an incredible 11 opsins – helping them to detect polarized light and in particular, the light reflecting off the surface of water.
If you stare into the eyes of a dragonfly, you are literally staring back into the ancient past. Dragonflies are among the oldest of insects on earth. More than three hundred million years ago, giant dragonflies with a wing span of more than two feet flitted among towering fern trees and horsetails. Scientists believe insects grew bigger because there were much higher levels of oxygen in the atmosphere.
Dragonflies vs damselflies:
In the Kawarthas you’ll frequently come across insects that look like dragonflies but they flutter more gently, much like butterflies. When they are at rest, their wings remain folded above their back. These are called damselflies. One of the most striking damselflies can be found along the banks of Jackson creek. With the inspired name of ebony jewelwing, their metallic green bodies reflect sunlight in way that makes them look like flying iridescent jewels.
Dragonflies, on the other hand, hold their two sets of wings down along the side when at rest. They also have huge, bulging eyes that wrap around their heads. And they are much more aggressive fliers. In the late summer and fall the rust or yellow-coloured dragonflies you see in fields, gardens and along shorelines are called meadowhawks.
The males are territorial. You’ll often see them hanging about a certain section of a field patrolling for insects and chasing other males away. On a hot day, watch for dragonflies doing a “handstand” also known as the “obelisk” position. They thrust their abdomen straight up in the air as a way to minimize sun exposure and avoid overheating.
1. Catch a baby dragonfly: Take a white pail and a net from the dollar store. Head to a nearby pond. Jackson Park has a lovely pond that will work well. Fill your pail up with clear pond water. Have the kids scoop up some mud just at the edge of the pond but underwater. Turn your net inside out and sift through the ooze. If you are persistent you’ll catch a baby dragonfly! If you feel comfortable, pick up the nymph between your finger and thumb. With your other hand carefully unfold the lower jaw or labium. You’ll see the pincers at the end of the jaw. Don’t worry it isn’t strong enough to pinch or bite you – but it sure is amazing to observe! Rinse some clear pond water over the nymph and place it carefully into the white pail. Can you see the abdomen rise and fall as it passes water over its gills and into its gill chamber? Don’t forget to release them when you are done.
2. Feed a dragonfly: If you encounter a group of hungry dragonflies feeding on insects such as swarms of flying ants (a common late summer event), crush a soda cracker into fine crumbs into the palm of your hands and scatter them into the air. Often dragonflies will swoop down and grab a crumb, thinking it is a bug. Watch how nimbly they scoop this up with their feet!
3. Catch a dragonfly: On a cool morning, venture forth with a net, a jar and quiet feet. Sneak up to a perching dragonfly from behind. Watch that your shadow doesn’t fall over your quarry. Gently slip the net over the dragonfly. If you wish to hold a dragonfly in your hand, place your thumb and index finger on either side of the thorax (the middle section where the wings are attached). Then gently move your fingers upwards and pinch all four wings together over the body. Carefully transfer the dragonfly to your jar for close up viewing. Despite what many people think, dragonflies cannot sting or bite you! Take special note of eye position, body shape and coloration, resting position and wing venation. Visit www.odonatacentral.org to help you with identification. Remember that the male and female in many species can be quite different.
Sometimes we humans forget the wonder in the very small. There is magic to discover under old logs, stones and along the muddy edges of ponds and streams. With the help of a net, a container and the urge to explore, you’ll discover the most amazing things close to home.
To paraphrase Mr. Rogers – “these are the critters of your neighbourwood.” Help your children learn more about their natural neighbours – so they can learn to care for and protect the very life systems that nurture and sustain us all.