Deadly Dragonflies (please don’t eat me)

Maria Bergman

Battelle Darby Creek Naturalist

How often do you ponder your chances of survival if you suddenly lived in prehistoric times? I think we’ve all wished at some point we could see a dinosaur roaming in the distance. Or maybe you didn’t learn from the cinematic Jurassic Worlds, and you’d like a much closer encounter. For me, it’s not the dinosaurs that would make my heart race as I roam the old earth. It’s the dragonflies.

According to fossil records, dragonfly species evolved before the time of the dinosaurs — over 250 million years ago. In natural history classes, we talk about the giant woolly mammoths, the giant sloths and the giant dinosaurs. But, we hardly ever hear about the giant dragonflies! Prehistoric dragonflies had a wingspread over 2 feet long; compared to modern species with 3-7 inches! As large as they were, they were also one of the only aerial predators of their time. They would feast on primitive insects, amphibians and lizard-like creatures (baby dinosaurs, anyone?) We believe the decreasing oxygen levels, and increasing aerial predators led to their modern-day sizes. I mean, phew! I wouldn’t want to take my chances evading those when I want to enjoy the waterways. Now instead of imaging yourself in prehistoric times, imagine yourself living as a small critter in Darby Creek today.

Do you ever watch shark week? If you do, there’s always many recordings of great white sharks hunting and ambushing their prey. While we don’t have sharks in the waters around us, we do have dragonflies — which just like sharks are a top predator eating everything in sight. If I asked you to list the top predators around the world, I bet you wouldn’t list species in Ohio. You might mention tigers, polar bears or lions. If you asked me, my first answer would be, again, a dragonfly. Young or old, in the water or on land, dragonflies are excellent predators.

Dragonfly eggs are laid in the water. When they hatch, the young spend about the next two to three years as nymphs in the water. Nymphs look similar to the adults, but without the mature organs and wings. If you look along the exposed roots on the sides of the creek, or clinging to the plants reaching in and below the water, you might find some. Each family of dragonflies look a little bit different, which helps them fit into the micro-habitat they prefer. But, let’s focus back to what makes them awesome predators. The nymphs live in the ever-fluctuating waters, and like sharks, they are great ambush predators. Think of the last time you played tag. Did you wish your arms could grow just a little bit longer on command? The advantage to doing just that is one of the three things that I think make dragonfly nymphs such good predators. Let’s look at that below.

1. Extendable reach: under the head of a dragonfly is their labium. Think of this as meat hooks on each side of your bottom jaw, that you can shoot out up to a third of your body length almost instantaneously. Very useful to catch food like other insects, tadpoles or small fish. (Remind you of any sci-fi movies?)

2. Fart attack: I’m sure if I polled our community of six-year-olds, they would say this is a great superpower. Dragonfly nymphs have internal gills in their abdomen, and are able to store and release water pressure which act as jet-propulsion, giving them extra speed alongside the reach.

3. Hide-and-go-hunt: it’s easy to win if your opponent doesn’t know they’re competing. Nymphs are excellent at waiting in stillness, covered in the debris around them as their prey gets closer and closer.

The nymphs will slowly develop their wing pads as they grow, until they are ready to climb up out of the water to break free and FLY! Most of the adult dragonflies we see around us live for three to five months. If you watch a dragonfly land, they will spread their four wings out to their sides. If you see something that looks a little bit smaller, and has its wings up along its back, you are probably looking at a damselfly instead. Even though they’re older now, the adults are still just as voracious as hunters, using the skills below.

1. If you can see it, you can eat it. Dragonfly eyes have 30,000 lenses; we only have one in addition to our cornea. With a quick tilt of their head, they are able to see the full circle of everything around them.

2. Pivot! Dragonflies have four wings, and unlike having two pairs of wings, they are able to independently move those to pivot their movement on a dime!

3. The basket carry! It’s not just taught for catching footballs. Why rely on just your mouth to catch prey flying away from you, when you’ve got legs to help scoop and trap the prey until you have time to devour your lunch.

I’ve got a lot more interesting facts we could share about these incredible species, but we’ve got to leave some information unstated, to draw you into attending naturalist programs. Interested in drawing dragonflies to your yard? Dragonflies like available water and plants to perch on. Even creating a mini pond in a pot would be helpful! If you’re scared of things that go bump in the night, dragonflies aren’t usually on that list. But does that really make you feel any safer in broad daylight? Good thing we aren’t small prey!