Damselfly

 Spotted this Common Blue Damselfly resting on the boat by the River Thames — a delicate flash of electric blue, perfectly still above the ripples. #WildlifeOnTheWater #RiverThames #Damselfly #NatureWatch

A Delicate Visitor: The Common Blue Damselfly and Its Dragonfly Cousins

While drifting gently along the River Thames last weekend, I noticed a vivid splash of electric blue perched delicately on the edge of the boat. At first glance, I thought it was a dragonfly, but a closer look revealed a more refined and slender guest — the Common Blue Damselfly (Enallagma cyathigerum).

This little insect is a regular summer visitor to rivers, lakes, and still water across the UK. With its fine build, translucent wings, and intense blue colouration marked by neat black bands, it’s as beautiful as it is understated.

But what exactly is the difference between a damselfly and a dragonfly? They’re both part of the Odonata order, but they belong to different suborders — damselflies to Zygoptera, and dragonflies to Anisoptera. And once you know what to look for, telling them apart is surprisingly easy.

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Damselfly vs Dragonfly: Know the Difference

Feature	Damselfly	Dragonfly
Body Shape	Slender and delicate	Stouter and more robust
Wing Position at Rest	Wings held together over the back	Wings held outstretched horizontally
Eyes	Eyes are separated	Eyes are large and usually touch in the middle
Flight	Lighter, more fluttery	Stronger, more direct and powerful
Typical Habitat	Calm waters: ponds, lakes, slow rivers	Wider range, often found near running water too

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The Common Blue Damselfly

This species is one of the UK’s most abundant damselflies. Males are a striking sky blue with distinct black markings along the abdomen, while females are typically more subdued in colour — often greenish or duller blue.

They are weak fliers compared to dragonflies, preferring to stay close to vegetation and resting often. Their presence is a good indicator of healthy water systems, as their nymphs develop in water before emerging as winged adults.

If you’re near the Thames this summer — or anywhere near water — keep an eye out for these small but stunning insects. You’ll likely spot them basking on reeds, boats, or even a paddle blade, soaking in the sunshine before flitting off to catch tiny prey.

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Final Thought

Nature has a way of sneaking up on you during the quiet moments — especially on the river. Whether it’s a flash of blue wings or a rippling swirl of water, take a moment to enjoy these fleeting encounters. The Common Blue Damselfly may be small, but it brings a little magic to any day out on the water.