Dragonflies are insects that belong to the order Orthoptera (winged bugs). They have two pairs of wings, which they use for flying. Most species of dragonflies feed on other insects such as aphids, caterpillars, spiders and even small lizards. Some species may also feed on other invertebrates like centipedes and millipedes. Other dragonfly species are known to lay their eggs in nymphal form inside other insects. These nymphs hatch into adults after several months.
A dragonfly’s body is covered with long, thin, transparent wings. The wing membrane consists of three layers: the outermost layer is made up of fine hairs; a second layer covers the wing; and a third layer makes up the inner part of the wing.
The inner part contains blood vessels and nerves. When dragonflies fly at high speed, they generate powerful jet propulsion through these muscles. Their wingspan ranges from 1.5 cm to 2 m (6 inches to 8 feet) in length. The wings are membranous, so they don’t need to be folded over when they’re not in use.
The adult female dragonfly has a pair of ovipositors located behind her head and between her eyes. She uses these organs during mating season to deposit eggs directly into the male’s mouth.
The male passes the eggs along in his body and then expels them sometime later. This process is called ovovivipary.
The front section of a dragonfly’s body consists of two wide eyes, a pair of long antennae and six long legs that are used for catching prey, climbing and balancing. A pair of wings sits on the middle segment, and the last part holds the dragonfly’s abdomen made up of all the essential organs.
Dragonflies have compound eyes made up of thousands of tiny lenses. These eyes give a dragonfly a wider field of vision, and they also have exceptional vision during the day as well as at night.
They can see in almost every direction at the same time, as their eyes are located on each side of their head. Dragonflies’ eyes also come equipped with multi-layer lenses that enable them to see in intense shade or bright sunlight.
Dragonflies belong to the largest insect order known as Odonates (tribe: Anisoptera). There are four main families in this order: Gomphidae, Aeshnidae, Libellulidae and Cordulegastridae.
The Odonates are notorious for their speed and agility when flying. In fact, they can fly at lightning speed.
They eat different types of insects like mosquitoes, as well as other flying insects and small frogs. Adult dragonflies can be found near large water bodies where they spend most of the time flying around near the surface.
A dragonfly’s body is covered with scales, which act like armor to protect the dragonfly. These scales also help with a smooth transition as it moves from air to water and vice versa.
As they grow, young dragonflies go through several nymphal stages. Each stage lasts a few weeks or months until they reach maturity.
The first stage of their life cycle is called the nymph (short for neonymph). This is when they hatch from eggs laid underwater. The newly hatched nymphs are called larvae.
Dragonflies are found throughout most parts of the world, except for in Antarctica. They live in fresh water like lakes and rivers, and they’re rarely found in saltwater habitats.
A dragonfly is a large insect belonging to theorder Odonata. Dragonflies can be identified by their four wings (two main wings and two hind wings) and a narrow body.
Most dragonflies are at least an inch in length with some species measuring over three inches.
These veins contain a network of tubes that transfer the water around the body and towards the wing muscles. Finally, when the wing muscles get a supply of water, they propel the wings open and push the dragonfly forward.
The heart is located in a chamber called a Because of this design, the blood has to travel in one direction only to prevent back-flow.
Dragonflies also have an exceptionally powerful heart. It is sometimes visible because it is located near the dragonfly’s head.
The heart is a thick muscular tube that can pump blood with great force. The heart also has multiple chambers (the pump sections of the heart) to pump the blood out quickly and efficiently.
The three main parts of a dragonfly’s body are its head, thorax and abdomen. The head contains the dragonfly’s many sensory organs.
These include a pair of large multifaceted eyes, a pair of small sensory antennae and other mouthparts used for eating.
While most insects don’t have ears, they do have a sophisticated network of sensors that help them to hear airborne and ground vibrations. These are helpful to dragonflies because they can sense the position of their prey, potential predators and mates without having to see them.
Dragonflies have a unique way of hunting their prey. Using incredibly sharp vision, they can see prey from a distance.
Then they use their sensitive hearing to follow the sound of the prey’s movements. Finally, when the dragonfly is close enough, it attacks with lightning speed. The dragonfly uses its large mandibles to kill and devour its prey.
Dragonflies have exceptionally good vision. They can see an object that is up to 8 km away!
The lenses in their eyes are special. They are made up of many strips of crystal, called facets. Each facet is like a tiny lens that focuses light onto the retina, helping the dragonfly to see clearly.
Dragonflies have three sets of jaws (a.k.a mandibles).
The foremost pair is large and is used to catch and hold prey as well as for fighting. The second set is smaller and is used to chew food and for attacking. The third set is so small they are virtually useless and are not used for either purpose.
The mouthparts of a dragonfly are quite different from most other insects. Most other insects have a sucking tube called a proboscis that they use to drink liquids.
Dragonflies do not have a proboscis, but rather have small needle-like mouthparts like a mosquito.
The respitory system of a dragonfly has an interesting design feature. Most insects breathe through a series of tiny holes called spiracles.
These are spread out over the body so that all parts get access to oxygen. This works well except in the middle of a hard wing beat, when the abdomen is compressed and can’t ‘breathe in’.
Dragonflies have large compound eyes that consist of hundreds of small lenses. These lenses work together and allow for excellent vision.
Each lens picks up light independently of the others. This gives the dragonfly good depth perception when hunting its prey or identifying potential predators.
The eyes of a dragonfly are located on the sides of its head. While this provides a wide field of vision, it limits the dragonfly’s ability to perceive depth.
Fortunately, the lenses in the compound eye help provide this information.
Sources & references used in this article:
Why snakefeeder? Why dragonfly? Some random observations on etymological entomology by BE Montgomery – Proceedings of the Indiana Academy of …, 1972 – journals.iupui.edu
Odonata: Dragonflies, Damselflies by KJ Tennessen – Encyclopedia of Insects, 2009 – Elsevier
A balancing act in urban social-ecology: human appreciation, ponds and dragonflies by J Silsby – 2001 – CSIRO publishing
What Bit Me?: Identifying Hawai’i’s Stinging and Biting Insects and Their Kin by RWJ Ngiam, WL Lim, CM Collins – Urban ecosystems, 2017 – Springer
The sting of the wild by GM Nishida, JAM Tenorio – 1993 – books.google.com
DRAGONFLIES AND DAMSELFLIES–OPPORTUNITIES FOR FURTHER RECORDING IN THE FORTH VALLEY by JO Schmidt – 2016 – books.google.com
Buzz, Sting, Bite: Why We Need Insects by J Willet – Naturalist Papers – fnh.natsci.stir.ac.uk