Nepedia
Back to Discover
Advanced Reader
🧬

Odonata

life science Maturity 7-9 Next article →

Odonata is an order of predatory flying insects. This group includes dragonflies and damselflies.

OdonataWings
OdonataWings

They are highly skilled hunters that spend much of their lives in the air. Most species are insectivorous, meaning they eat other insects. Because they are such effective predators, they play a major role in their ecosystems. Scientists who study these insects are called odonatologists. The name Odonata was coined by Johan Christian Fabricius in 1793. He took the name from the Ancient Greek word for "tooth." This likely refers to their toothed maxillae, which are part of their mouthparts.

Odonates are divided into two major groups based on their physical traits. The first group is the Anisoptera, often called true dragonflies. These insects are usually bulky with large compound eyes that sit together. When they rest, they typically hold their wings spread up or out. The second group is the Zygoptera, or damselflies. These are generally more slender than dragonflies. Their eyes are placed apart on their heads. When damselflies rest, they fold their wings together along their bodies.

Common blue damselfly02
Common blue damselfly02

The way these insects fly is very different from many other insects. Most flying insects use indirect flight muscles attached to their thorax. However, Odonata use direct flight, where muscles attach directly to the wings.

OdonataWings
OdonataWings

This allows them to control each of their four wings independently. They can change the angle, frequency, and twist of every wing. Most families also have a structure called a pterostigma on the leading edge of the wing. This is a thickened area filled with hemolymph, which is insect blood. The pterostigma acts as a weight to help the insect glide. It prevents self-exciting vibrations, known as flutter, from happening at high speeds.

All Odonata begin their lives as aquatic larvae called nymphs or naiads.

070526 142326 Libellen cr
070526 142326 Libellen cr

These young insects are voracious predators. While they mostly eat other insects, they can overpower small fish, tadpoles, or even newts. Damselfly nymphs breathe using external gills on their abdomen. Dragonfly nymphs breathe through a special organ located in their rectum. As they grow, they undergo approximately 9 to 14 molts. Eventually, they transform into flying adults. This life cycle makes them very sensitive to the quality of their water habitats.

The fossil record for Odonata is incredibly complete, stretching back 319 million years. Their broader group, Odonatoptera, appeared as early as the Late Carboniferous period. This makes them one of the earliest groups of winged insects.

Meganeura
Meganeura

Some prehistoric relatives were much larger than modern species. The Meganeuropsis permiana was an extinct insect from North America. It had a body length of 70 centimeters and a wingspan of 70 centimeters. This makes it one of the largest insects to ever live. Studying these fossils helps scientists understand how flight evolved in insects.

Today, Odonata come in many different sizes. The giant Central American helicopter damselfly, Megaloprepus coerulatus, has a massive wingspan.

Megaloprepus coerulatus Drury
Megaloprepus coerulatus Drury

On the other end of the scale is the Nannophya pygmaea. This dragonfly from East Asia is only 1.5 centimeters long. The smallest Odonates are species in the genus Agriocnemis. These damselflies have a wingspan of only 1 centimeter. These extreme sizes show how much the order has adapted to different environments.

Because of their biology, Odonata are excellent bioindicators. This means their presence tells us about the health of an environment. They need high-quality water to develop from nymphs to adults. If a river has many different types of Odonata, it often means the water is clean. Their numbers also reflect the abundance of prey in the area. Additionally, a high variety of dragonflies often correlates with a high variety of plants. However, they are sensitive to rising temperatures. As the climate changes, many species are moving to higher elevations or different latitudes to survive.

624 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (7)
File:Common blue damselfly02.jpg
Common blue damselfly02.jpg
File:OdonataWings.jpg
OdonataWings.jpg
File:Meganeura.png
Meganeura.png
File:Megaloprepus coerulatus Drury.png
Megaloprepus coerulatus Drury.png
File:Epiophlebia_superstes_f.png
Epiophlebia_superstes_f.png
File:Illustrations of Exotic Entomology II 47 ('LIBELLULA AXILENA').jpg
Illustrations of Exotic Entomology II 47...
File:070526 142326 Libellen cr.jpg
070526 142326 Libellen cr.jpg
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.