The sense of smell is a powerful one. A whiff of this or a whiff of that can send your mind tripping back to times gone-by. For me, the heavy musky smell of a summer evening catapults me back to the grassy fields of my youth. Fields filled with the sounds of crickets and the flash of fireflies. High over-head, Common Nighthawks would repeat their raspy call—peent, peent, peent. But mostly I remember the precision flights of dragonflies as they wing across the tops of the tall grasses in search of a meal.
It wouldn’t be summer without dragonflies. These critters have been around for a long time. Their fossil record dates back 350 million years ago. That’s about 100 millions years before the dinosaurs.
There are over 5,000 different species of dragonflies in the world. In North America there are about 400 species and a little over 100 species in the Northland.
Like all insects, the dragonfly has three body parts—the head, thorax and abdomen. The head of the dragonfly has two huge eyes. The eyes are so big that in some species they actually merge together on top of the head. Each eye is made up of hundreds of individual eyes–called compound eyes. The head of a dragonfly swivels freely allowing the dragonfly extraordinary field of vision.
The thorax is the small segment in the middle of the dragonfly. It’s where the four wings and six legs are attached. Lastly, the abdomen is what most people call the tail. It is long and thin and is often mistakenly thought to be a stinger. It is important to note that no dragonfly has the ability to sting.
You can tell a dragonfly from the similar looking damselfly by looking at their wings. All dragonflies hold their wings flat or horizontal and out to their sides when at rest–like the wings of an airplane. The damselfly folds their wings neatly over their backs when at rest.
Dragonflies have four wings, which allow them to fly forwards, backwards and hover. The top speed of a dragonfly is around 35 mph. A dragonfly’s life revolves around flying. They capture and eat their food while flying and they even mate while flying.
Their diet is mainly small flying insects like mosquitoes. This is how they got the name “mosquito hawk”. They catch their lunch by holding their legs like a catcher’s mitt, and scoop the prey up while in flight. A typical dragonfly can eat hundreds of insects a day. This pernicious behavior goes a long way to help keep mosquito populations down.
While eating during flying isn’t very hard, mating on the wing is a little tricky. The male searches out a receptive female and locks on to her just behind her head with a small pair of pincers located at the tip of his tail (abdomen). The female curls her tail up and receives a reproductive packet from the male. This position is called the wheel and is easily observed. Because females will mate with several males if allowed, the male tries to stay locked on to her while she lays her eggs to ensure he is the father of the offspring. The two will fly around together as she deposits hundreds of individual eggs underwater.
The eggs hatch into tiny alligator looking insects with a voracious appetite. At this stage of life they are called a naiad. For the next two years the naiad aggressively seeks out and eats mosquito larva, small tadpoles and even small fish. After several molts it attains full size and crawls out of the water onto a rock or vegetation. The back of the naiad splits open and the adult dragonfly emerges. After several hours the dragonfly wings are dry and ready to fly off to eat more mosquitoes and mate, thus completing the dragonfly life cycle. Until next time…