Dragons and damsels

 

Story and Photos by Scot Stewart

Imagine living in the depths of a murky pond for a year or two, waking one morning, crawling out of the water, cracking and climbing out of your skin and flying away. That is the life of many aquatic insects, but none does it more gracefully than dragonflies and damselflies.

Dragonflies and damsels are ancient—the first dating back 300 million years, starting with primitive dragonflies at the very end of the Carboniferous Period and into the Permian Period as the Paleozoic Era began to wind down. Things didn’t move that fast then, especially the Permian as it lasted 65 million years.  In the early days, dragonflies lived in those famous swamps seen in prehistoric time—just without the dinosaurs. There were large tree ferns, but they were giving way to smaller ferns and plants called equisetum or more commonly known as horsetails.

During this time part of what is now the United States was experiencing uplifting and some glaciation, causing some areas to dry out.  The atmosphere is thought to have had 50 percent more oxygen. Animals started moving toward land. The first snails appeared. Scorpions and spiders became dominant land animals, followed by lizards, crocodiles, dinosaurs and birds as vertebrates developed eggs with waterproof shells. Mayflies and dragonflies took to the air.  The highly oxygenated air provided the extra boost animals like insects needed to take in to grow much larger than today. Fossils of dragonflies from this time reveal they had wingspans of up to 25 inches—more than 2 feet.

Today there are around 5,000 species of dragonflies and damselflies worldwide. Some scientists believe there may be more than 1,000 still waiting to be discovered. Damselflies are the smaller cousins, with smaller eyes on the sides of their heads, equal-sized wings and a habit of folding their wings up over their bodies. Dragonflies range from having a wingspan of slightly about ¾ of an inch to 7-and-a-half inches, have eyes nearly covering their heads and larger hind wing pairs than forewing pairs.  Dragonflies rest usually with their wings spread perpendicular to their bodies.  Damselflies are often overlooked and many may believe they have never seen one.  People fishing may have found a bright neon blue insect land on the end of their pole or on the line—it was a damselfly—one named the familiar bluet.

Dragonflies and damselflies are shape shifters.  Their lives go through one of the greatest transformations of any animal. The ugly duckling has nothing on them. Their lives take them from the dim light of sometimes murky ponds to the bright light of an Upper Peninsula sky.

Adult male dragonflies of many species find an area they defend from all other males. Their defense may result in nasty fights involving grabbing and biting. Some males may be killed in these battles. Their aggression carries over to mating as well. They actively pursue females, and grasp them with three appendages on their tails when the females fly into their territories.  Their mating is often conspicuous and the pair can be seen flying or perched together. It is often a noticeable event for damselflies as the two form a heart-shape pattern with their two, long slender bodies. Males have three structures at the tip of their abdomens to hold onto a slender area behind the female heads.  Pairs can often be seen flying together as the females lay eggs on the surface of water or when they land on aquatic vegetation and the females attach eggs to the plants below the water surface.

Sometimes males can be overly aggressive and attempt to separate mating pairs or attempt to mate immediately after a pair separates while the female is laying eggs.  To avoid these males, some females choose quieter, more vegetated area to lay their eggs or even feign death, sometimes literally dropping out of the sky when pursued.  National Geographic reports on a study in Switzerland, by Rassim Khelifa, at the University of Zurich who found more than 60 percent of females were successful using this strategy.

When eggs hatch, the great progression of changes in the lives of these amazing insects begin.  Young follow an incomplete metamorphosis, a three-stage life cycle—egg, nymph or naiad aquatic phase, and the adult dragonfly stage.  More familiar insects like butterflies have a four-stage life—egg, pupa (caterpillar), pupa (chrysalis) and adult (butterfly).  Like caterpillars, the naiads live inside a fixed rigid exoskeleton (outer covering).  And just like a little boy in too-small pants that split at the seam, a naiad outgrows its covering, splits it open and crawls out.  The new outside skin hardens. A naiad spends up to three years in pond or shallow lake water, and can shed up to 12 times.

Naiads look like armored race cars or miniature crabs, depending on the species, usually dark olive green or brown to blend in with their surroundings and can even grow algae on their skin to complete their camouflage outfit. They use their cryptic coloration to help them hunt larvae of other insects like midges and mosquitoes, and larger prey like minnows and tadpoles of frogs and toads, but will eat virtually anything they can catch below the surface of the water primarily using the ambush method of attack. Damselflies look similar, but have three feathery gill membranes waving from the end of their abdomen.

Their lower mouth part acts like a two-pronged spear gun, using hydraulics to operate.  The naiad draws water in the back end of its digestive tract, then clenches muscles at the end to increase the pressure of the water.  That pushes a lower mandible, called a labium out of the naiad’s mouth to grasp its prey, then pulls it back into its mouth as the water inside is released.  For more information and some fantastic photography check out an article on the web about their feeding habits at https://www.wired.com/2013/12/the-secret-underwater-world-of-dragons/.

They are hunted by other aquatic animals like fish, toads, salamanders and frogs.  Nestled in vegetation on the bottom they are difficult to see, but do have a secret weapon if chased.  Filling their digestive track with water, they can force it out the end of their abdomen and become jet propelled again, using an elaborate hydraulic system. That’s a movement!

Once the naiad has fully matured it crawls up a stalk of vegetation or another rigid structure like a pole or the leg of a ladder on a dock just before dawn. Once several feet above the water they rest, then split their skeleton along the back and crawl out one more time. Now the final and most amazing transformation begins.  After unfolding their wings, they begin pumping fluid into the dark veins, stretching, then drying them out.

After anywhere from two hours to a couple of days they are ready to fly.  Looking like helicopters, they actually have more versatility and capabilities than their mechanical counterparts.  Able to fly up to 35 miles per hour, they can dart off using great acceleration, hover, fly straight up or down or backward, even fly upside down.  Looking totally graceful with their nearly clear wings, they can skim the water, turn on dime, or even a tiny lily pad, and chase down a mosquito, blackfly, fly, butterfly, or smaller dragonfly.

They are built to be some of the most efficient predators in the animal world. Dragonfly eyes cover nearly their entire heads, allowing them to see almost the entire sphere of their world. The only blind spot they have is directly behind them. Their legs form a basket, each leg laden with sharp spikes to hold their prey.  The most amazing part of their bodies though is their nervous system.  Their bodies are hotwired with a nerve system running from their eyes, each made of 30,000 simple lenses, to neurons (similar to brain cells).

These neurons have the ability to help the dragonfly track its prey, closing down other parts of its vision so the dragonfly can focus on its prey, predict where it is going, and align its body to continue to follow the prey efficiently. As they close in, they drop just below their target to come in at the most unsuspecting angle. The neuron research was a collaboration reported in Science Daily. This design allows some dragonflies to catch hundreds of mosquitoes each day, making them a wonderful camp companion.  Even better, the old myths about being darning needles able to sew up young children’s lips or bite someone are untrue. Some do believe, and this could be true, that if a damselfly lands on your fishing pole or line, you will catch a fish. Pretty sure about that one.

Dragonflies and damselflies do have to watch for predators too. Larger dragonflies, birds (especially flycatchers and swallows), frogs and spiders, using their strong webs as traps, are enemies of both insects. Car and truck grills also take their toll.

Their grace and agility make them a joy to watch.  Some birders have expanded their activities to include dragonfly watching—they are elusive, colorful and very engaging.  And even though there are only half as many identified dragonflies and damselflies as birds, it might take twice, maybe three times as long to see all of them.

Some also follow dragonflies on radar because there are a few species that actually migrate.  Scientists can watch Doppler radar at night and look for slender, dense bodies, indicating a group of dragonflies migrating south. Some studies have revealed they can travel up to 7.5 miles a day, and fly every third day. They seemed to fly after a colder night, indicating they might use north winds to help them along. One intrepid dragonfly that was wired with a small (really small) satellite tracking device held on with eyelash glue and superglue flew 100 miles nonstop. There is even one species that flies 10,000 miles over the Indian Ocean and back each year. There aren’t many helicopters that can do that without several servicings.

One of the most delightful experiences one can have with a dragonfly, or even a flock of them, is to stand on a quiet dirt road in a mosquito or blackfly factory on an early summer day and watch as the dragonflies dart around you, scooping the pesky devils right out of the air around you. The only difficulty with watching is the dragonflies, who maintain a 90 to 95 percent success rate at catching prey, cannot keep up with the number of prey.  You just wish there were more dragonflies.

Probably the best experience though is getting up before dawn on a cool, dewy morning and heading down to a nearby pond or lake to look for another early riser—a new dragonfly.  Just out of its old skin stretching out its new, dewy wings while a peachy sun rises behind it, it is just a fantastic event to see at the start of your day.  It is just hard to beat.

MM

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