Dragonfly

April 20, 2024

There has been a lot of chatter about the double cicada hatch that begins this month.  The 17-year “Northern Illinois Brood” (Brood XIII) and the 13-year “Great Southern Brood” (Brood XIX) are emerging during the same year for the first time in 221 years.  The hatch will span as far east as North Carolina and as far west as Missouri, as far south as Louisiana and as far north as Wisconsin, although Michigan will not be as buggy as other states.  The cicada larva constructs an exit tunnel out of the ground and crawls up the sides of buildings and trees to gain height for their flight.  They then molt (shed their skins) on a nearby plant for the last time and emerge as adults. The abandoned exoskeletons (exuviae) remain, still clinging to the bark of the tree.  While I have seen several exoskeletons the full hatch has yet to occur.  When I went out to my pool/pond yesterday I was surprised to find three exuviae clinging to the tarp covering the water that were obviously not cicada.  These were instead the molt of a species of dragonfly.

When I looked online, I found a dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata.  The infraorder Anisoptera comes from Greek anisos (“unequal”) and pteron (“wing”) because the hindwings of a dragonfly are broader than their forewings.  Of the 3,000 known living species most are tropical, with fewer species in temperate regions.  An adult dragonfly is characterized by a pair of large, multifaceted, compound eyes, two pairs of strong, transparent wings, and an elongated body.  Many have brilliant iridescent or metallic colors produced by structural coloration, making them conspicuous in flight.  A dragonfly is a predatory insect, both in their aquatic nymphal stage (called “naiads”) and as adults.  Although some species live up to five years as nymphs, most have an adult lifespan in the order of five weeks or less, and some survive for only a few days.  They are fast, agile fliers capable of highly accurate aerial ambush, sometimes migrating across oceans, and often live near water.  The loss of wetland habitat threatens dragonfly populations around the world.  My three individuals had completed their larval stage in my pool, then crawled out of the water to molt and dry in the sun.  Only their exuviae remained clinging to the tarp.

The adult dragonfly hunts on the wing using their exceptionally eyesight and strong, agile flight.  They are almost exclusively carnivorous, eating a wide variety of insects ranging from small midges and mosquitoes to butterflies, moths, damselflies, and smaller dragonflies.  A large prey is subdued by a bite to the head and then carried to a perch.  The wings are discarded, and the prey is usually eaten headfirst.  A dragonfly may consume as much as a fifth of its body weight per day.  The nymphs are also voracious predators, eating most living things smaller than themselves.  Their staple diet is bloodworms and other insect larvae, but they also feed on tadpoles and small fish.  A few species, especially those that live in temporary waters, leave the water to feed on small arthropods at night.  Some species in the Anax genus have even been observed leaping out of the water to attack and kill full-grown tree frogs.  My 2 inch (5 cm) long individuals had been hidden in the pond.  The only way I discovered them was the exuviae left behind as they began their adult life.

THOUGHTS:  A dragonfly has been genetically modified with light-sensitive “steering neurons” in its nerve cord to create a cyborg-like “DragonflEye”.  The neurons contain genes like those in the eye to make them sensitive to light. Miniature sensors, a computer chip and a solar panel were fitted in a “backpack” over the insect’s thorax in front of its wings.  Light is sent down flexible light-pipes (optrodes) from the backpack into the nerve cord to give steering commands to the insect.  The result is a “micro-aerial vehicle that’s smaller, lighter and stealthier than anything else that’s manmade”.  And you thought AI was going to be a problem.  Act for all.  Change is coming and it starts with you.