Creature Feature: Dungeons & Dragons & Damsels Galore
This Creature Feature can be viewed both as a follow-up to last month's feature, which focused on mayflies, or as a stand alone edition. No matter the interpretation, we shall continue to delve into the whimsical world of aquatic and semi-aquatic insects. At some point in our lives, we’ve likely had dreams or imaginations about being in a fantasy world of magic, dragons, and royalty. In reality though, the only dragons we have on this planet are connected by name only (Komodo dragon, bearded dragon, etc.). The insects that will soon be revealed are associates as well, but they are not the same scale-like dragons or damsels in distress as anticipated.
Members of the insect order Odonata are a group of flying predators that prey on other insects. The two insects that make up this order include dragonflies, and damselflies. Both share some similarities, such as starting off as nymphs underwater and having long slender bodies as adults. However, there are also key differences that separate the two, despite both being a part of the same order. Let's take a look at each kind of odonate:
Dragonflies
There are approximately three thousand species of dragonfly found throughout the world. Their flying skills come from two pairs of wings that, when resting, are stretched out and away from their bodies. Despite their bright colors, most of a dragonflies life is spent as an underwater nymph that feeds on other insects and invertebrates. Like fish, dragonfly nymphs possess gill-like structures to help them breathe. Their gills, however, are not located on its sides, but rather at…how should I put this?... the very end of its digestive system, if you know what I mean. By expelling large amounts of water from that same area, a dragonfly nymph can propel forward very quickly whether to hunt or avoid danger.
In order to grow bigger, it molts several times (it varies, depending on the species). When it is ready to become an adult, it emerges out of the water and proceeds to molt one last time, at which point the dragonfly is acclimated to the new oxygen source and its wings have been achieved. WIth their new wings, dragonflies can go up, down, left, right, forward, backward, but oftentimes are found basking in the sun near water because it needs that heat energy to power their wings.
Adult dragonfly (left) and adult damselfly (right).
Source: University of California Museum of Paleontology
Damselflies
Like dragonflies, damselflies are also predatory insects, but are usually smaller and thinner. One of the biggest differences that separates the two is that their wings, when resting, lay parallel to their bodies as opposed to being stretched outward. Their species count closely matches the amount of dragonfly species observed throughout the world, of which previously mentioned was about three thousand.
As nymphs, damselflies are more slender than their dragonfly cousins. The gills of a damselfly appear as stretched out fan or hair-like tails at the end of their abdomen, whereas the ends of a dragonfly appear as a few prominent spines (called paraprocts), depending on the stage of molt.
Both a damselfly nymph (top) and dragonfly nymph (bottom) on a glass
Because different odonate species sometimes require specific requirements for their breeding wetlands, such as temperature, depth, flow, pH, some scientists may view these insects as bioindicators: a term given to a species or group of organisms that give scientists the indication what the state of the habitat is currently in, such as being healthy or polluted.
Now go find me a dragon.
Click here to learn more about dragonflies and damselflies
Submitted by naturalist Zack Mork, June 2024