Dragonfly

A dragonfly is a flying insect that belongs to the suborder Anisoptera of the order Odonata. There are about 3,000 kinds of dragonflies alive today. Most live in tropical areas, but some live in temperate regions.

Dragonflies are special because they have big, many-sided compound eyes, two pairs of strong, clear wings, and long bodies. Many dragonflies have bright, shiny colours that make them easy to see when they fly.

Dragonflies love to fly and are very good at catching other insects. They can fly very fast and accurately, and sometimes they fly over oceans. Dragonflies live near water. They grow underwater in a stage called the nymphal stage before they become adult dragonflies.

Dragonflies have been important in many cultures. People have made dragonflies on pottery, in paintings, and in jewellery. In some places, dragonflies are symbols of courage and happiness, while in others they are seen as mysterious. Their beautiful colours and quick flight have inspired many writers and artists.

Etymology

The name Anisoptera comes from Ancient Greek words. Anisos means "unequal" and pteron means "wing". This name refers to dragonflies having broader hindwings than their front wings.

Evolution

Dragonflies are related to an ancient group called griffenflies. These insects lived about 325 million years ago in Europe. Some griffenflies were very big, with wingspans as wide as 30 inches.

True dragonflies, called Anisoptera, first appeared during the early Jurassic period. They have kept some traits from their ancient ancestors.

Today, there are around 3,000 different kinds of dragonflies found all over the world. They belong to a group called Palaeoptera, meaning 'ancient-winged'. Unlike many modern insects, they cannot fold their wings against their bodies, though some have found special ways to do it.

Distribution and diversity

About 3,012 kinds of dragonflies were known in 2010. They live on every continent except Antarctica. Some dragonflies can be found in many places, like the blue-eyed darner, which lives across North America and Central America. Others, like the globe skimmer, can be found in warmer areas on all continents. Most dragonflies live in tropical areas, with fewer in colder regions.

Dragonflies can live in many different places, from sea level up to high mountains. Some live in desert pools and can survive in very hot temperatures. They become less common in very cold areas, like Iceland or northern Alaska, but sometimes strong winds can carry them to new places.

Description

Dragonflies are strong insects with heavy bodies. They hold their wings out to the sides when they fly and when they rest. Unlike damselflies, dragonflies do not fold their wings when they are not flying.

An adult dragonfly has a head, a thorax (midsection), and an abdomen (tail section). The head is big and has two large eyes made up of many tiny parts. They also have three smaller eyes and mouthparts for biting. The thorax has three parts and holds the wings and legs. Dragonflies have two pairs of long wings and three pairs of legs used mainly for catching prey and landing on plants. The abdomen is long and slender with ten sections.

Young dragonflies, called nymphs, look different from adults. They do not have wings or reproductive organs. They have a special lower jaw to catch food. Some nymphs breathe through gills inside their bodies, while others use gills outside their bodies or a special tube to breathe underwater.

Biology

Dragonflies and damselflies are hunters, both when they are young in water and as adults. The young, called nymphs, eat small water creatures. Bigger nymphs might eat tadpoles or tiny fish.

Adult dragonflies often gather in groups to hunt flying insects like ants or termites.

Dragonflies live in many places, from flowing rivers to still ponds. Some need special plants or water to survive.

Dragonflies are strong and agile fliers. They can hover, fly fast, change direction quickly, or even glide. Their wings beat in different patterns. They can reach speeds up to about 54 km/h (34 mph) and see very well.

Dragonflies go through an incomplete metamorphosis. Eggs hatch into nymphs that live underwater. After several molts, the nymph climbs out of the water, sheds its skin, and emerges as an adult.

Predators

Dragonflies are fast and can fly well, but some animals can still catch them. Birds like the American kestrel, the merlin, the hobby, nighthawks, swifts, flycatchers, and swallows sometimes eat dragonflies. Some wasps also hunt dragonflies to lay eggs on them. In the water, ducks, herons, newts, frogs, fish, and water spiders eat young dragonflies, called nymphs. Amur falcons that fly over the Indian Ocean may eat dragonflies.

Parasites

Dragonflies can be affected by three types of organisms: water mites, gregarine protozoa, and trematode flatworms (also called flukes). Water mites, called Hydracarina, can harm smaller dragonfly nymphs and sometimes appear on adult dragonflies. Gregarines infect the gut and might cause problems there. Trematodes are parasites of animals like frogs. Dragonfly nymphs can get infected by swallowing cercariae or by them passing through their body wall. Once inside, they form a cyst and stay there until the nymph becomes an adult. If a frog eats the infected nymph, the frog can become infected.

Dragonflies and humans

Conservation

Many scientists who study dragonflies live in colder places, so most research is from areas like North America and Europe. But most dragonflies live in tropical areas, where they are not studied as much. When forests are cut down, dragonflies can disappear because their homes, like streams and pools, dry up or get filled with dirt.

People are working to protect dragonflies by creating special areas where they can live safely. These areas help keep their homes healthy. More research and ways to reduce pollution are also needed to help dragonflies survive.

In culture

Dragonflies have been important in many cultures. In ancient Egypt, people made dragonfly-shaped decorations. For the Navajo and other Native American groups, dragonflies represent clean water. In Japan, dragonflies are linked to autumn and are seen as symbols of strength and happiness. They appear often in Japanese art and poetry.

In Europe, some old stories thought dragonflies were scary or evil, giving them names like "devil's darning needle." But today, many people enjoy watching dragonflies, and they are popular in art and design.

In poetry and literature

Writers and poets have often used dragonflies in their work. Japanese poets wrote many poems, called haiku, about dragonflies. Famous poets like Matsuo Bashō wrote beautiful lines comparing dragonflies to autumn. In Europe, poets like Lord Tennyson described dragonflies in their poems, comparing their shiny wings to sapphire.

In technology

Scientists have added tiny sensors and a small computer to dragonflies so they can follow light signals. This lets the dragonflies act like tiny flying machines that can be controlled with light, which could be useful for many purposes.