Beetle Beetle: description of development, measures of protection from insects

Bread beetle, or, as it is called, "kuzka", is a pest of barley, wheat and other cereals. These insects belong to the family of lamelliformes, a group of coleoptera. Pests are familiar to many residents of Russia and Ukraine.

Description of the insect

Beetle bugs are pests, differ in green, almost blue shade of legs and body. Their elytra is dark brown in color, they have longitudinal grooves. There is a dark spot near the scute (in females). The size of this insect is 13-16 mm. Their eggs are globular in shape, white in color, approximately 2 mm in diameter. The length of the larva is up to 35 mm. It is white in color, and its head has a yellowish-brown hue. Further, a brown pupa up to 17 mm long appears. Beetles begin active life in June-July. At this time they live on the ears. The females lay eggs in July. They lower them into the soil to a depth of up to 20 centimeters. At the time the female is able to bring about 50 eggs. Beetle kuzka all stages of development takes place in the soil. Depending on the temperature, eggs can "ripen" during a period of 2 weeks to a month. The period of development of the larvae lasts up to 23 months, during which time they experience two wintering at a depth of up to 80 centimeters. By May of the second year, the larva rises higher and turns into a pupa at a depth of 15 cm. The duration of development of the pupa lasts from 10 to 20 days. In late May - early June, a young beetle is already flying out.

Distribution of insects

The homeland of this beetle is the European steppes. It is common in Moldova, in some parts of Western Europe, in the European part of Russia and in the steppe regions of Ukraine. In addition, it lives in the steppes of Turkey, Kazakhstan, the Urals, Altai, and the North of Iran. The beetle inflicts significant harm in southern Russia and in the black earth regions of Ukraine. It also significantly harms Azerbaijan and parts of Kazakhstan.

Ecological characteristics

Beetle Kuzka is a thermophilic creature. Young individuals begin to leave the earth only if the air is warmed to a temperature of at least +17 degrees. At a temperature of +20 ⁰ C, the eggs begin to ripen in the females for masonry. These insects are very active. They eat only in the daytime, especially if the weather is hot. At nightfall, they sink to the ground. If the weather is bad, cool, they do not rise from the soil. Therefore, only in the hot and dry summer of the bug beetles begins active reproduction, with this period usually falls on the time of earing grain crops. If the summer turned out to be cold and rainy, the number of insects sharply decreases, second-year larvae can die. In this case, during a drought, they try to go deeper into the soil. Adult individuals select cereals and feed on them. They prefer spring forms of rye, barley and wheat. These insects love not only cultural species, but also wild ones. So they choose a wheatgrass, wheat grass, timothy grass, a fire and others. These pests mainly "occupy" the edges of grain fields. The beetle kuzka eats the flesh of immature crops, and ripens the mature grains from the stems.

In the first year of development, the larvae use humus and thin rootlets of all kinds of plants. In the next year of life, their main diet consists of the roots of sugar beet and cereals. Birds like to eat both imago and their larvae. The main enemies of the kuzka are predatory beetles, chrysomes and sporules.

The damage caused by beetles

Harm not only the adult bug beetle, but also its larvae. Each year, one individual eats about 8 grams of grain, but even more, he simply knocks out of the ears. Thus, he can destroy up to 10 spikelets. Larvae cause damage in another way. They feed on plant sprouts and the roots of cereals, which in turn leads to sparse shoots. It is believed that this type of beetles is harmful when the number of more than three pieces per one square. Km. So, if the density of sowing on km ² is about 250 stems and the number of beetles is more than 10, the yield loss reaches 50%. If you take the years that are favorable for the spread of this beetle, then along the edges of the fields on one square. Km can be counted up to a hundred individuals.

Measures to protect crops from beetles

In the period of the end of the spring and the beginning of the summer, it is necessary to cultivate and process the rows. Such an event leads to the mass destruction of pupae of these beetles. Also at the beginning of the wax ripeness, it is necessary to carry out a quick separate cleaning, picking up the rolls. Such actions also reduce the amount of damaged grains. In addition, to ensure that the grain beetle does not crawl out of the ground for the next sowing year, it is necessary to conduct early post-harvest autumn plowing, and also to perform stubble peeling. These actions lead to the death of eggs and larvae before they deepen into the lower layers of the soil.

If the number of beetles exceeds the severity threshold (more than 3 pieces per 1 sq. M.), On wheat during the ripeness period it is necessary to arrange spraying of the culture with insecticides, CE (l / ha) sumithion - 0,8-1 or deciose extra - 0,05. The last spraying should be carried out no later than 20 days before harvest.