Dragonfly

Shimmering

Once I laid down in green pastures
the sun so hot it dried my tears. I drifted off somewhere
not to sleep, exactly, some place better, beyond dream

Nudged awake by a tickle, I sat up. There they were:
three double-winged dragonflies, the size of hummingbirds
fluttering on my belly, my left knee, my foot.

I tried not breathe
for fear they’d leave me

Bronze and blue and bronze and blue
luminescent wings fanning me
in perfect rhythm

my father
my brother
my son

My dragonflies the size
of hummingbirds stayed
until the first snow

I was the one

finally

who had to shake them off
who had to fly away
who became

a hummingbird

a dragon flying

a shimmering

Sheree Fitch

Dragonflies aren’t one species, but rather a group of over 3000 species. They are often portrayed as a symbol of luck in many cultures, but there is much more to this insect than luck! The earliest fossil record shows ancestors of the dragonfly 325 million years ago.

Physical Description

Like all insects, the dragonfly has 3 main segments of its body: the head, thorax and abdomen. Dragonflies, like most insect species, have different stages. Young dragonflies, called nymphs, are as different from adult dragonflies as caterpillars are from butterflies. Nymphs live in water where many people don’t notice them. Nymphs have three sets of legs, large eyes and small bumps where four wings will later develop. Dragonfly nymphs have a tough exoskeleton, a rigid external body covering, that they will grow out of six to fifteen times as they grow. For a photograph of a dragonfly nymph, check out: https://bugguide.net/node/view/56505

As adults, the dragonfly’s abdomen will become long and thin. Dragonflies have four wings and six legs attached to the thorax. Its large wings are mostly transparent with noticable veins; the adult’s body can have metallic and iridescent colours, including yellow, red, green, blue, brown and black. Dragonflies have two compound eyes, which are made up of multiple photoreceptors that each show one image; some species can have up to 30,000 lenses per eye, enabling them to create an accurate image of the world around them. Dragonfly nymphs and adults have a unique mouth part called a labium, that they shoot out and pull in to catch and eat prey.

Habitat

Multiple dragonfly species live on every continent, except for Antarctica. They are more abundant in warmer and tropical areas. As latitude increases, the number of species decreases. Many species of dragonfly still live in the north however. Their most desirable habitat is a shallow sunlit strip of water surrounded by vegetation because dragonfly eggs are laid in the water.

Reproduction

Many dragonfly species are territorial. Males will fight each other for specific habitats. They will use intimidation tactics such as charging at each other, displaying their bright colours, or physically fighting for control over the territory.

When a territory is established and it is time to mate, the male will hold the female behind her head and carry her to the territory to mate. Each species has specific holding techniques, helping to reduce interspecies breeding. A female can lay 1500 eggs in one clutch, and she will lay them on or inside vegetation growing on the water. The development of the embryos will not start until the water rises and the eggs are covered by water. After a week, the eggs will hatch, releasing nymphs into the water. The nymphs will spend up to four years (the majority of their life) developing underwater, progressing through multiple stages. When it is time to become an adult, they will emerge out of the water, anchor themselves to a plant, and shed their exoskeleton, revealing wings and an adult body. The adults live for up to six months, just until they can reproduce.

Diet

Dragonflies are predatory hunters and almost exclusively carnivorous. When in the nymph stage, dragonflies eat insects or any types of larvae found in shallow water. The adults eat insects such as midges, mosquitoes, butterflies, flies, ants and moths. They will use their labium to catch their prey and then bite into their heads to kill its prey before eating the rest of the body.

Biomimicry

Many insects beat their wings very fast. Most of them use some sort of “elastic energy storage” to do this. This means that some sort of elastic substance (usually a protein called “resilin” in insects) is squashed or stretched by the muscles and then it rebounds, enabling insects like dragonflies to beat their wings.

Scientists are particularly interested in dragonflies because they are very impressive fliers; they can fly quickly, hover AND fly backwards and sideways. Dragonfly movements have been mimicked to make small robotic vehicles called “MAVs” or Micro Air Vehicles.

Interesting Facts:

Dragonflies are often confused with damselflies, which look very similar. Damselflies are a bit smaller, but the main way to tell the difference is wing placement at rest. A dragonfly at rest will keep its wings outstretched and horizontal. Damselflies will fold their wings into their abdomen at rest.
Dragonflies can fly on average 16 km/hr, with a maximum speed of 36-54 km/hr.
Dragonflies are used in many Japanese and Chinese cultures as traditional medicines.

Ryan Small