Beautiful Demoiselle (Calopteryx virgo)
Beautiful Demoiselle (Calopteryx virgo)
Beautiful Demoiselle: Shimmering Hunter by the Water
The beautiful demoiselle is a dazzling hunter of our streams and rivers. Learn everything about its appearance, behavior, diet, and distribution.
Key Facts
- Size: 45–50 mm body length, wingspan about 60 mm
- Weight: a few milligrams to about 0.1 g
- Diet: mosquitoes, flies, small insects; larvae eat small aquatic animals
- Flight season: May–September, larvae overwinter in water
- Distribution: Europe, preferring clear, slow-flowing waters
- Habitat: clean streams and rivers with vegetation
- Special features: males with deep blue wings, females brownish-transparent
Table of Contents
- Introduction
- Appearance
- Characteristics
- Diet
- Reproduction and Life Cycle
- Seasonal Behavior
- Distribution and Range
- FAQ
- Conclusion
Introduction
Perhaps you have noticed a shimmering flash of blue above a sunny stream, fluttering like a jewel over the water. Chances are, it was the beautiful demoiselle – one of the most striking dragonfly species in Europe. It is not only a gem of our waterways but also a skilled predator. In this article, we dive deep into its life: from its dazzling looks to its graceful aerial displays.
Appearance
The beautiful demoiselle lives up to its name.
Males shine with a metallic blue-green to emerald-green body. Their wings are broadly darkened, shimmering from deep blue to almost black depending on the light.
Females are more subdued. Their bodies gleam in greenish metallic tones, while their wings are transparent to brownish. A typical feature is the pale patch near the wingtip – the so-called pseudopterostigma.
The body is slender and elongated, about 4.5 to 5 centimeters long. They also have large, dark compound eyes that provide a wide field of vision. Their antennae are short and inconspicuous, and their legs are black – perfect for gripping plants but poorly suited for walking.
Characteristics
- Size: body length about 45–50 mm
- Wingspan: up to 60 mm
- Weight: a few milligrams to 0.1 g
- Males: dark, deep blue wings
- Females: transparent to brownish wings with a pale patch
- Flight style: buzzing, elegant, often above shallow waters
The species is easy to distinguish from other dragonflies because its wings are almost completely dark – a unique feature within its family.
Diet
The beautiful demoiselle is an aerial hunter. It catches small insects such as mosquitoes, flies, and small moths in flight, using its long legs like a net.
The larvae, also called nymphs, live in water. They feed on insect larvae, worms, and small crustaceans. They capture prey with lightning speed using a “mask” – an extendable lower jaw that snaps forward like a harpoon.
Reproduction and Life Cycle
Summer marks the most spectacular phase of its life: reproduction.
Males defend small territories along the banks. To impress females, they perform elaborate aerial displays. If a female shows interest, mating occurs – in dragonflies, this is called the “mating wheel.”
After fertilization, the female lays her eggs in the water or in submerged plants. These hatch into larvae, which spend one to two years underwater. During this time, they molt several times before climbing up plants on a warm day. Then their outer skin splits open, and the adult dragonfly emerges – a breathtaking moment you may be lucky enough to witness.
Seasonal Behavior
Adult dragonflies, also called “imagines,” are most active from May to September. Populations peak in midsummer, when courtship is at its height.
While adults live only a few weeks, the larvae spend the winter in water. Their development speed varies depending on climate and location – sometimes lasting several years.
Distribution and Range
The beautiful demoiselle is found across much of Europe. It is especially common in Central Europe.
Its preferred habitats are clear, clean streams and rivers with abundant riverside vegetation. It inhabits both lowlands and uplands. In northern and southern Europe, different subspecies occur, distinguished by subtle variations in wing patterns.
FAQ
When is the best time to observe the beautiful demoiselle?
Between May and September, especially on sunny midsummer days.
How can you tell males and females apart?
Males have deep blue wings, while females have brownish-transparent wings with a pale patch near the tip.
Where does the species prefer to live?
In clean, slow-flowing streams and rivers with rich vegetation.
How long does an adult beautiful demoiselle live?
Only a few weeks, while the larval stage in water lasts one to two years.
What do the larvae eat?
Small animals such as insect larvae, worms, and small crustaceans.
Conclusion
The beautiful demoiselle is far more than a shimmering splash of color by the water. It shows how rich life can be in clear streams and rivers. Its presence tells us: the water is clean, the balance is intact. Once you have seen it in flight, you will not forget the sight – a sparkling piece of nature reminding us how precious healthy habitats are.
