Stretching the stream

DRAGONFLY

BY GAURAV NAVALKAR

Name

Common Name : Dragonfly

Scientific Name: Anisoptera

Family : Eg: Aeshnidae (hawkers or darners) eg Blue spotted hawker

Order :Odonata

Description

Dragonflies are heavy bodied, strong flying insects that holds the wings horizontally when at rest

An adult dragonfly’s body is divided into head, thorax and abdomen.

The head is large with very short antennae and covered by very large two compound eyes

The mouth has a toothed jaw, a flap-like labrum at the front to catch prey

The thorax has 3 segments; holds two pairs of wings and three pairs of legs

The wings are long, veined and membranous, narrower at the tip, wider at the base

The abdomen is long and slender and has 10 segments

Dragonflies come in varying sizes; they are usually between 1-4 inches in length

Dragonflies come in bright colours – blue, green, red, yellow

Dragonflies are found near wetlands or near water.

Life Cycle

Life Cycle Egg & Nymph

The female dragonfly lays eggs in batches on moist surfaces, plants submerged under water or in water directly.

Dragonfly eggs are round and about 0.5 mm long

The eggs hatch usually within a week to couple of weeks. The time for hatching depends on the atmospheric temperature and the climatic surroundings.

The eggs hatch into larvae called nymphs which again live in water.

Nymphs have large eyes, 6 legs, - often flat on underside, - no tails. Their size ranges from 1/2" - 1 1/2“

Nymph stage is the longest stage in the life cycle of a dragonfly. This stage usually lasts anywhere from a year up to four years

Dragonfly nymphs are shorter and bulkier, and the gills are located inside the abdomen. They look spider like.

Nymphs shed their skin anywhere from 6 to 15 times during their life cycle

Life Cycle Adult Dragonfly

An adult dragonfly has a long body, transparent wings, and large eyes.

It has 6 legs, a thorax, a head, and an abdomen. The abdomen is long and segmented.

Even though the adult dragonfly has 6 legs, it cannot walk properly but is a fast flyer.

Size of an adult dragonfly may range from 1-5 inches

An adult dragonfly is the most colourful insect; colours range from blue, green, red, yellow

The adult stage could be the shortest life-cycle stage ranging from few weeks up to a year

Food Chain

They eat They get eaten by

Gnats Birds

Moths Lizards

Flies Ducks

Butterflies Fish

Habitat

Dragonfly's live near wet lands and water

They like to live in warm climates.

Adaptive Features

Dragonflies are well known for their speed.

They can move forward at a rate of roughly 100 times their own body length each second, sometimes reaching speeds of around 55 miles per hour.

They're also able to move backward, sideways and diagonally bit slowly.

Their speed and agility mean they can quickly zoom away from and outmanoeuvre any potential predators. It gives them an advantage when hunting for prey, too.

Interesting Facts

Many dragonfly species can get up to 7-8 cm long

Dragonflies at nymph stage live in water. This is the longest stage in their life-cycle. The nymphs have gills inside the rear of their abdomen. They obtain oxygen by contracting their abdomen to pump water in and out of the gill chamber.

Fossil Dragonflies have wing spans up to 2 metres and were almost a meter in length

Dragonflies hold their wings horizontally at rest

Dragonflies respire not only through their gills, but also through their wing pads.

Bibliography

http://www.dragonfly-site.com/dragonfly-facts.html

http://www.bugfacts.net/dragonfly.php

http://en.wikipedia.org/wiki/Dragonfly

http://www.eduwebs.org/bugs/dragonfly.htm

http://www.ucmp.berkeley.edu/arthropoda/uniramia/odonatoida.html

http://animals.pawnation.com/adaptive-characteristics-dragonfly-8616.html

http://www.ecospark.ca/changingcurrents/dragonfly