Dragonfly: structure, description and photo

In this article, we suggest that you talk about how,what kind of creature is a dragonfly. Structure, nutrition, reproduction, benefits and harm - these are all our main questions, which you will find the answer after reading this short article.

To begin with, we will make a reservation: the dragonfly has six segmented limbs. This is an insect belonging to the subclass of winged insects. These numerous creatures have even their own squad - dragonflies.

Have you ever thought about how you gotis the name of a dragonfly? In the Russian language it is a combination of two obsolete words: izaza and strekat. The first word is translated as fidget, and the second - to jump. This name completely characterizes the manner of flight of these fast creatures called the dragonfly. The structure is the first question that we will consider right now.

Structure

Dragonfly, the structure of which we consider inThis material has a long and very thin trunk. It, in turn, is connected with the cephalothorax. On the dragonfly's body we can see three pairs of legs and two pairs of wings. It is also important to note that the wings are transparent, they can have the same size and shape, and different. We will discuss this in more detail when we consider species. A dragonfly, the structure of which can vary from species, can refer to one of two main groups:

• The isomorphic.
• The naked.

As it is not difficult to guess, the first group concludesin themselves individuals that have wings of equal length and shape, while others - on the contrary (one pair can be very different from the other). On the head of a dragonfly, we can clearly distinguish between large eyes and antennae. A little more about the senses. The eyes of these insects are complex. You can divide them into two departments:

• Top, responsible for object recognition;
• lower, responsible for color recognition.

You probably noticed that the transparent wingsdragonflies along their entire length have veins, and on their tips the spots are darker than the color of the wings themselves. This device helps to avoid fracture of the wings, reducing vibration during flights.

Remember how the flight of other flyingcreatures. This is a beautiful and synchronous movement of the wings. Dragonflies and then distinguished themselves, the movements of the wings can be asynchronous when they balance, and synchronous to increase the speed. It is also important to know that these savage creatures can develop a flight speed of up to 50 kilometers per hour.

Lifespan

We examined some features of the structure of dragonflies, but it is important to clarify that they can live up to ten years. These are real long-livers in the world of insects. Let's talk about this a little more.

Total on our planet there are more than 6.5thousands of species of these unusual, graceful and beautiful creatures. On the territory of Russia you can meet a small number of species, about 150. So, the lifespan of dragonflies directly depends on the species, at least it's two months, and the longest survivors can exist for about ten years. This period includes the full cycle of development of insects, and the development of the larva in certain species can take many years.

Kinds

The external structure of the dragonfly directly depends on the species. There are only three suborders of these insects:

• isotopes;
• heterosexual;
• anisozygoptera.

What are they different? The first species has two pairs of wings, they are narrow and almost the same shape. If the dragonfly is at rest, then both the front and rear wings are raised upwards and connected together. In the second case, the wings have different shapes, at rest they are spread out to the sides. The third genus belongs to the only genus, these insects are common in Japan and India. The peculiarity of the latter is also that they combine the signs of the first and second suborder.

The most common representatives of winged dragonflies:

• Beauty.
• Arrow.
• Ljutka-Dryad.
• Megaloprepus caerulatus.

It is very important to know that the last of these are the biggest dragonflies in the world. The length of their bodies reaches ten centimeters, and the wingspan of nineteen.

Bright representatives of the suborder heteropteran:

• The scout-emperor.
• The cordwood logger is annular.
• The head is metal.
• He's an ordinary girl.
• The dragonfly is ordinary.

Habitat

Features of the external structure of the dragonfly and methodReproduction is directly dependent on habitats. These insects prefer to stay and conduct their life activities near the water. How can you explain such a gravitation to the water element? It's very simple: the dragonflies lay eggs in the water.

They choose places near the mountain swiftstreams, ponds, lakes, rivers and canals. There are also species of dragonflies that prefer swamps. Dragonflies are sun-loving insects, they often bask in the sun on clearings and meadows. However, they do not fly far from the water. On cloudy and rainy days the dragonflies do not fly out, prefer to be in the "shelter".

Food

Our next question is the internal structuredragonflies and nutrition. As mentioned earlier, the dragonfly is a type of arthropod. We know that in representatives of the type of the circulatory system is not closed, the heart looks like a multi-chamber vessel. The brain and the ventral nerve chain represent the nervous system of insects.

What can talk about developed gnawing mouthapparatus, well-developed vision, elongated body and large, rather powerful wings? Of course, dragonflies are predators. They prefer to eat their prey directly on the fly. They feed on insects, usually harmful. Large they catch paws, and small (midges, mosquitoes) catch straight jaws. To taste large prey, the dragonfly has to descend to the ground. Hunting is a real sight. Even such good and bright flyers, like flies, do not escape from the clutches of dragonflies. It is important to know that representatives of dragonflies are very voracious. During the day they eat prey several times their weight (for example, flies can exterminate over forty per day).

Reproduction

We examined the peculiarities of the structure of dragonflies,method of nutrition and habitat. Now briefly about the method of reproduction. Fertilization occurs in the air. The larvae are deposited by the female mainly in standing water, their number reaches five hundred. This amount is necessary because of the poor survival of the larvae. The larvae are deposited in various ways:

• dropping into water;
• partial immersion;
• full immersion in an air bubble.

In this form, larvae can be from twentydays to nine months, it all depends on the type of dragonfly, the environment and other factors. After appears pronima (life cycle a few seconds), then a naiad. Further, the larva develops from several days to several years.

Benefit and harm

The benefit is that adult dragonflieseat annoying and harmful insects (mosquitoes, flies and others), their larvae exterminate the larvae of mosquitoes. However, dragonflies spread a dangerous disease of birds - protogonimosis. Larvae of some representatives are able to eat fry in the fishery.