Coleoptera, or beetles, are considered the largest order in the animal kingdom. More than one million species are known in the world, of which seven hundred thousand belong to the class of insects, three hundred thousand are beetles. Every year, scientists discover and describe dozens of new species.
Representatives of the order of beetles, or Coleoptera, have rigid front wings that can grow together in the middle of the back, thereby forming a special protective cover for the hind wings. Coleoptera are believed to be the only insects that primarily use their hindwings for flight.
Distribution of Coleoptera
They are ubiquitous and found in a variety of places, such as under logs, rocks, in gravel near rivers, and in fresh water. Larvae can be found under the bark of diseased trees or even in the remains of decaying animals.representatives of beetles, or beetles.
Food
For the order of beetles, almost any animal or vegetable matter can become food.
Some species eat plants, others feed on insects, snails or other small invertebrates. In addition, there are species that love to feast on decaying or dead tissues of animal or plant origin.
Structure and physiology
Representatives of Coleoptera can be of various sizes. For example, the Hercules beetle, which is common in Central America, can grow up to fifteen centimeters long, while other small beetles are no longer than five millimeters.
The torso of adults, as a rule, has three main parts - this is the head, chest and abdomen. This division is the same for all representatives of insects. However, there are features that can be used to distinguish beetles from other representatives of insects. The beetles raise the elytra during the flight, thereby creating lift, or they remain folded. However, in order to fly, most beetles need only spread their wings and jump up. Large and heavy individuals for this need to crawl onto the plant and pre-warm up in the sun.
Head
Representatives of Coleoptera have antennae on their heads, or they are also called antennae, as well as a mouth organ, usually withhorizontally moving parts of the gnawing type. The upper and lower jaws, the lower lip is included in the oral apparatus. For example, in phytophage beetles, the lower jaws look down, while in predatory representatives, they look forward.
The organs of vision in beetles are poorly developed compared to other insects, so they rely on a well-formed sense of smell. The only exception is predatory species. The antennae contain olfactory receptors. For example, in a dung beetle, they look like plates that can move apart and fold. Hearing is also poorly developed. Some representatives are able to produce different squeaks due to the friction of body parts against each other. In addition, they make sounds by tapping their heads against hard objects. For example, the grinder beetle is able to tick like a clock by tapping its head against the wood where it makes moves.
Chest
The second part - the chest - consists of three segments. The first one has only a pair of legs. In general, beetles have a larger prothorax than most insects. The next segment consists of leathery or strong (hard) elytra and a pair of legs. On the third segment or metathorax is the third pair of legs, hind membranous wings that can fold and hide under the elytra.
Belly
Behind the chest is the torso, which consists of several parts and is closed with elytra from above. Representatives of Coleoptera have a cuticle, which acts as an external skeleton and body cover. As a rule, it is thicker and stiffer than many others.insects. There are black, brown, shiny color. And in some beetles, it is covered with colored spots, stripes, or a pattern similar to the natural environment in which it lives.
Mobility of Coleoptera is very limited due to the fact that the integument of the body is hard, therefore, if the beetle turns upside down on a flat surface, then in most cases it will not be able to take its original position on its own. Rigid cuticle, as well as elytra, perfectly protect the insect from moisture loss and mechanical damage.
Internal structure
Representatives of the Coleoptera order have the same internal structure as other insects. Under the cuticle is the heart, and the nerve chain runs along the lower part. Beetles have an open circulatory system, so the blood freely flows around the internal organs, and is not enclosed in arteries and veins. Coleoptera breathe air that penetrates through special tubules on the sides of the body, and then it enters through the tubes to all tissues.
Some families of Coleoptera
More than a hundred families of beetles are known. Coleoptera representatives (list):
- Flowers. There are about 2100 representatives of this family. Adults have a smooth and streamlined body. Basically, these animals are painted black or dark brown. Males have large round pads on their front paws.
- Leaf beetles. This family is recognized as one of the largest in the Coleoptera order. They feed mainlyvegetable food. They have a spectacularly colored body with a metallic sheen, some representatives have a pattern made up of stripes. Some representatives, for example, earthen fleas, jump well. The principle of the jump is the same as that of the grasshopper, thanks to the similar structure of the hind limbs, which have a thickening in the upper part.
- Virtyachki. About four hundred species are known. They live in groups most often in the coastal zone of rivers and lakes. Insects have an oblong-oval shape. With their external shiny and smooth appearance, they resemble apple seeds. The organ of vision is divided into lower and upper parts, which differ in the size of facets and are adapted to see under and above water.
- Horses. There are approximately 1300 species. These are quite mobile and interesting insects that can be painted in red, blue or green colors with a metallic sheen on the underside. And on top of the body is a sandy or red hue with a pronounced pattern. Horses are mainly found in sandy areas. They can be seen on hot sunny days. Thanks to their sharp and long mandibles, they are able to run fast and defend themselves from enemies.
- Ladybugs. There are more than three thousand species. They are classified as predators, although in external parameters they are completely different from them. They lack long legs, large and bulging eyes. It is likely that this is due to the fact that they prey on slow-moving prey, such as aphids, scale insects. These representatives of beetles have a round body a little more than a centimeter long. Elytra orangeor red, covered with black dots.
- Kozheedy. Members of this family are very small. Spotted body. They live on the remains of decaying animals, in pantries, under carpets, in furs, leather.
Insects-representatives of Coleoptera undergo a complete transformation in their life cycle, starting with the egg stage and ending with the adult. An interesting fact: it turns out that every fifth living creature on planet Earth is a beetle. An exact answer about their origin has not been found so far. The remains of ancient beetles are found in layers aged 250 million years, at that time it was a rare animal species. Beetles are popular and favorite insects for collectors.
