I get this question in person more than I see it online. So let’s break it down shall we? What are dragonflies and damselflies? How are they similar? How are they different? And take a deeper dive than you might find normally with a quick google search.
First, we’ll want to look at where they came from and their common ancestor. Looking at how they’re similiar will help us notice the subtle differences that help us tell them apart.
They’re Old. Like … Really Old
Starting about 325 million years ago … give or a take a few … earth had magnificent dragonfly-like things flying around. Like 2ish foot long dragonfly things. These giant fliers were originally characterized in the same order, or higher grouping as dragonflies and damselflies but have been removed and put into their own order (Meganisoptera / Previously Protodonata). Despite having many similarities; aquatic nymphs, four large wings, spiny legs, and being aerial predators as adults – taxonomists recently put them in their own grouping. Taxonomists like to take a close look at things. No, a closer look. Closer. Yeah. There you go.
Mainly the wing venation is what we were looking at here. These pre-odonata, lack certain wing venation characteristics that modern dragonflies and damselflies have.
Modern damselflies and dragonflies have more complicated wing venation with more cells and a group of darkened cells call the Pterostigma. This section is hardened in the wing to help with stabilization while the insect is gliding.
Okay okay – so dragonflies and damselflies are now in this order Odonata – are they really that different from each other? Well … yeah actually. The separate right after this higher order grouping into two suborders. Anisoptera – Dragonflies and Zygoptera – Damselflies.
Let’s compare and contrast the adults.
Dragonflies (Anisoptera) tend to hold their wings out at rest. The wings are a bit uneven with the forewing being a bit skinnier and the hindwing a bit broader. Anisoptera means “different wing” referring to their wing shapes between the forewing and hindwings are different. They’re largely robust, strong fliers, and their eyes tend to meet in the middle of their head but one notable exception is the family Gomphidae (Clubtails) that have large separated eyes [example further down].
Some dragonflies can fly at speeds of 40 MPH and the Globe Skimmer Dragonfly (Pantala flavescens) is the most widespread dragonfly because it can fly over oceans in their migration! They’re literally found all over the world.
Many people will say that dragonflies are “larger” than damselflies. I don’t think that is a fair comparison because dragonflies are more robust – thicker bodies – big chunky thoraxes – but there are some little dragonflies! They’re small but definitely chunky. Surprisingly, the largest odonate in the world is actually .. a damselfly!
Damselflies (Zygoptera) on the other hand are a bit more delicate looking. If dragonflies are the rugby players of the world, damselflies would be the dancers. In fact – there’s a whole bunch of damselflies called “the dancers.”
Damselflies have long, slender bodies. Most hold their wings together above their back at rest and the wings are all basically the same shape. “Zygoptera” means “same wing” referring to their similar looking fore and hindwings. Their eyes are also widely separated. While dragonflies look like bombers zooming through the air, damselflies gracefully flit through making them look more graceful all around.
Of course… there’s always exceptions. There are a few groups of damselflies – most common in North America is the family Lestidae (spread wing damselflies) that holds its wings open at rest like some kind of dragonfly wannabe. There’s other families in the tropics that do the same thing, which is why just IDing from wing position alone isn’t always a good idea. In South America, a couple other families such as Heteragrionidae (Flaymboyant Flatwings) and Megapodagrionidae (Long-Legged Flatwings) and Philogeniidae (Duskey Flatwings) all hold their wings out as well.
What I believe to be a damselfly in a small family Heteragrionidae that’s one of those tricky damselflies that sit with its wings open. However, you can tell it’s still a damselfly by its skinny body and separated eyes.
PC: Nancy Miorelli
Their Babies! – Nymphs
Damselflies and dragonflies do not go through complete metamorphosis. They do not have a pupal (cocoon, chrysalis) stage. However their babies, called nymphs (or sometimes naiads) live in the water before emerging as their final aerial form. Even at their aquatic stage – it’s pretty easy to distinguish the two suborders between damselflies and dragonflies.
Dragonflies and Damselflies have unique moutparts as nymphs called the Labial Mask. It opens and extends like an arm sitting right under their chin. Some larger dragonflies can catch fish and tadpoles with it and chomp down on it without a second thought. Deep Look from PBS did an amazing video on these nymphal hunters.
Dragonfly nymphs (left) have their gills inside their abdomen. That’s right. They breathe through their butt and can even jet propulsion themselves out of harm’s way. They’re generally roundish and kind of stocky looking. Damselfly nymphs look like they have a propeller sticking from their butt and these are their gills. They’re generally more elongated. Sometimes their wing pads stick up and seem a bit more detached than those of their dragonfly counterparts.
Photos: Nancy Miorelli
Dragonflies (Anisoptera) and Damselflies (Zygoptera) may look the same at first glance, but once you get a closer look at them you can really start to see the differences even in their nymphal aquatic stages! Generally adult dragonflies are thick and robust insects often holding their wings out at rest with eyes that tend to touch each other in the middle of the head. Their nymphs are also round and stocky with their gills interalized. Adult damselflies are skinnier, eyes are separated on the ends of their head, and often hold their wings together at rest. As nymphs, they’re skinny and you can see their gills extending off the end of their abdomen like propeller. I hope you enjoy looking at these beautiful animals in your backyard and now have a new found appreciation for their subtle differences.
Photos: Nancy Miorelli
Bota-Sierra CA, Sandoval-H J, Ayala-Sánchez D, Novelo-Gutiérrez R. Libélulas de La Cordillera Occidental Colombiana: Una Mirada Desde el Tatamá. Colombia 2019.
(It’s written in English and Spanish)
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