Nutcracker beetle or wireworm - what the main pest of garden crops looks like

The Nutcracker Beetle got its name thanks to the original sound that it makes when jumping. The larvae of this insect are called differently - wireworms. This name is, as they say, a folk name and was given because of the special structure of the body - in the nutcracker larvae it is very elongated and has shiny covers. These small insects are considered quite a serious pest of crops and can threaten the death of a significant part of the plantings. How to recognize the "enemy"?

Description

An adult nutcracker is a medium or large insect, the body length of which varies between 1-75 mm. His body is flattened and oblong. Elytra rather stiff; in most cases, puncture grooves can be seen on them; as a rule, they have a metallic sheen. The color of the nutcrackers can be different and depends on the insect subspecies - in some the body has a uniform black or brown color, in others on the pronotum and elytra the pattern composed of colored spots, stripes or patterns will be visible. There are also tropical species whose color is most striking - the body of such insects is painted in catchy satin shades: orange, red, yellow, blue, green, etc.

As can be seen in the photo, the body of the nutcracker is sometimes covered with small hairs and scales. The head, which occupies about a third of the body, is pulled into the pronotum. She has a pair of small round eyes and antennae, each of which is divided into 11 segments. The wings are well developed. There are three pairs of long legs, all walking type, claws on the legs.
A peculiarity of the nutcracker beetle is a process formed by the middle chest and prothorax. This is a kind of jumping mechanism that allows the insect to roll over at the right time. When the beetle is turned with its back to any surface, it bends the prothorax and focuses on the pronotum. In this position, the sprout is ready. The nutcracker sharply bends the prothorax to the other side, due to which the process strikes the base of the elytra, thus tossing the body up. The insect, once in the air, flips and lands on its feet.

On a note! Nutcrackers do such tricks not out of boredom, often this skill saves their life, for example, when it is necessary to escape from danger. In addition, this mechanism helps insects that spawn from the pupa to move in a dense substrate!

Larva

At the larval stage, the nutcracker or, more precisely, the wireworm, looks like a caterpillar. Its elongated flattened body is divided into 13 identical segments in structure, which only slightly differ in size. The body has a cylindrical shape. The integument is highly sclerotized; their shape is usually wrinkled and punctate. More often the body is almost naked, but sometimes larvae are found, the body of which is densely covered with small hairs. On the head capsule, the chitin cover is the densest and darkest. The head has the shape of a quadrangle, slightly narrowed in front.

Antennas are located on the head, each of which consists of three segments.In the front part there are powerful mandibles represented by mandibles - the lower jaw, and maxilla - the upper jaw.

The wireworm larva has three pairs of legs, all are equally developed.

Over time, as it grows and develops, the body of the insect becomes covered with weak chitin, painted in white, beige or muted yellow. At this time, the wireworm larva becomes a pupa. Thin processes appear at the corners of the pronotum during this period.

Life cycle

The Nutcracker Beetle leads a daily life. The full life cycle takes from 3 to 5 years, and its duration will depend on the conditions in which the insects live. The main factors that influence this are the ambient temperature and humidity level.

1. Egg. The female makes the first clutch around the end of April. She hides the eggs under lumps of substrate, in small pits in the ground, or gently lays them at the base of seedlings. In one clutch, there are 3-18 eggs. The female nutcracker does some masonry, and at the same time, this process can take several months. The development in the egg lasts 2-4 weeks, which depends on environmental conditions and on the insect subspecies.
   

   On a note! In one season, one female is able to lay from 100 to 230 eggs!

2. Larva. After 2-4 weeks, larvae emerge from the eggs, the size of which does not exceed 0.2 cm. They are very voracious and, as a result of intensive feeding, by the end of the year their body sizes increase markedly - up to 0.7 cm. After some time, the larva reaches 2 cm in length. The larval stage takes 2-4 years.
3. Dolly. The grown and sufficiently strengthened larvae of the nutcracker beetle pupate and go into the soil where they winter. The pupal phase lasts, as a rule, no more than 30 days.
4. Imago An adult grows out of the pupa in spring.

Nutrition and harmfulness

Thus, it becomes clear where the wire comes from. Young women with the arrival of heat simply leave the substrate after wintering and almost immediately begin to lay their eggs. Moreover, the main threat to crops is precisely the larvae that are in the soil. In the first year of life for plantations, they are harmless, but upon reaching the second year they become extremely voracious. Having a particularly strong body structure, they literally pierce root crops and rapidly destroy their flesh, which quickly leads to complete disrepair. Often, not only the tubers of plants, but also the buds, thin stems and rhizomes are at risk of destruction.

Propagation of nutcracker beetles can occur in any area where there is vegetation. The main danger is that even a temporary absence of succulent seedlings does not guarantee getting rid of this parasite. Waiting for a tidbit, the wireworm for some time is able to be content with weed grass, and females at this time will lay eggs on wheat grass and burdock.

Important! Often gardeners make a mistake by leaving weathered grass in the aisles. Under such conditions, the nutcracker will multiply even more actively and subsequently the grown individuals will surely move to the beds, where they will destroy root crops with tremendous speed!

Most commonly, wireworm larvae are found in crops such as:

• nightshade;
• cereals;
• cabbage;
• aster (sunflower).

Several species of wireworms live throughout the post-Soviet space, but three are considered the most harmful: Melanotus, Agriotes and Selatosomus. These parasites most commonly affect potatoes. They bite into tubers and at the same time can damage the stem. As a result, the damaged bush begins to noticeably yield in growth, develops slowly and gives a meager harvest. Bacteria and fungi penetrate the tunnels gnawed by the larvae, which subsequently causes rot. Such tubers lose their market value.

Often a nutcracker bug attacks grapes. In this case, the insect destroys the buds of the plant and significantly spoils the juicy shoots. In vineyards, as a rule, pests of the genus Agriotes gurgistanus and Selatosomus latus are active.

Sometimes adult nutcracker beetles enter apartments. As a rule, they fly in the summer in open windows or in windows.An insect found in a room or in the kitchen should be removed immediately. Otherwise, the female will be able to lay eggs on your indoor plants or among food stocks, which subsequently threatens their safety.