Dragonflies: Beautiful Predators

Misty Sunrise at Pearl Lake - August 2023

​Glimpsing a dragonfly while on the trail is a special treat. These sightings put a little extra spring in my step because they are an unexpected gift. I usually notice the bright flash of green or blue, and I smile to watch the long, elegant body with its four shapely wings flitting through the greenery near the creek. Dragonflies symbolize transformation, which I find hopeful and encouraging. I’m curious why dragonflies do not also symbolize perspective, considering that their head is made up of many compound eyes with thousands of lenses. They can see up to twelve meters (over 39 feet) in all directions in order to spot what they’re hunting. (Woodland Trust: What Do Dragonflies Eat? and Other Dragonfly Facts)

Dragonflies spend a large part of their lives as larvae (nymphs) in the water, and as adults, around the water. Lakes, streams, rivers, ponds, and even bogs are their home. These habitat areas are sensitive; a robust dragonfly population is an indication of the health of these environments, and the reverse is true. Since dragonflies snack frequently on insects like mosquitoes it behooves us to nurture these habitats, and thus the dragonfly population.  (Bridgewater State University article: Life Cycle of Dragonflies and Damselflies)

Dragonfly life as an adult is relatively short, usually just a few months, giving them just enough time to reproduce. Dragonflies are carnivorous predators. In addition to mosquitoes, they eat midges, flies, small butterflies and even other dragonflies. 

In general the dragonfly life cycle follows this pattern:

1. Eggs are deposited directly into the water, or into sand or a plant in close proximity to the water.
2. After hatching from the egg the nymph remains in the water for several months or several years, feeding on insects and tadpoles.
3. When ready - sometimes triggered by warming water temps in spring and summer - the nymph makes its way out of the water and clings to a plant or rock, taking in air to expand its entire body. The skin behind the head splits and the adult dragonfly pulls itself out of what was its body - now a shell called the exuviae.
4. After several hours of drying time, the adult dragonfly is ready for liftoff and flies away to find its first meal out of the water.

Dragonflies come in an astounding number of shades - yellow and black striped, iridescent green and blue, brown and black. Different species also boast fascinating names. Here are a few (find more details and excellent pictures in this Sweetgrass Farm Garden blog post: Exploring the Different Families of Dragonflies):

• Darners, due to the darning needle appearance of their bodies.
• Clubtails, as the distal end of the body is enlarged, resembling a club.
• Petaltails, for the attachments on their abdomen resembling petals.
• Cruisers, because of their penchant for not dawdling in one watery home for long.

Dragonflies are sometimes mistaken for damselflies, and vice-versa. The two are closely related but there are a couple of ways to tell them apart. When perched, the damselfly pulls its wings in and behind its body, while dragonflies keep theirs out to the sides. Typically, damsels have a slightly smaller and more slender body than the dragons.

Dragonflies predate dinosaurs. From the fossil record, these prehistoric dragonfly insects, called  Meganeuropsis, had a wingspan of 75 centimeters, or 29.5 inches! Though our current-day dragonflies are related to Meganeuropsis, they clearly have evolved to a size that works better in today’s environment. (Earth Archives: The Biggest Insect Ever Was a Huge “Dragonfly”)

Lest you think dragonflies are all whimsy, know that they are considered the most successful predator, with a hunting success rate of 95%. The movie Alien borrowed from the dragonfly nymph’s ability to move their lower jaw like an arm, so quickly the prey doesn’t know what just happened as they are being swallowed by the nymph. (Willistown Conservation Trust article: Dragonflies: Nature’s Most Successful Predator)

Sources/Learn More

• NPS St. Croix National Scenic Riverway Dragonfly Fact Sheet
• Woodland Trust: What Do Dragonflies Eat? and Other Dragonfly Facts
• Bridgewater State University article: Life Cycle of Dragonflies and Damselflies
• Sweetgrass Farm Garden blog post: Exploring the Different Families of Dragonflies
• Earth Archives: The Biggest Insect Ever Was a Huge “Dragonfly”
• Willistown Conservation Trust article: Dragonflies: Nature’s Most Successful Predator