Four-spotted weevil

Four-spotted weevils belong to the insect family. These are beetles of medium size, the black body of which is from 1 to 22 mm long. The four-spotted weevil – the male differs from the female in the structure of the antennae and legs, the more convex posterior part of the abdomen.

On the back and elytra there are hairs that form a pattern in the form of spots or the letter “X”. Antennae, paws, in whole or in part, have a yellowish-reddish color. The head of the insect is small and slightly retracted into the front chest. The back of the pest has a trapezoidal or oval shape. Hind legs of a beetle are thicker and longer than the middle and front ones.

The four-spotted weevil in the enlarged photo is clearly visible, allowing you to see all the details in detail. This insect does not live on the territory of the Russian Federation. But it can be delivered with leguminous crops from the countries of Central Asia. Most often with soybeans, peas, chickpeas and other grains. Her relatives are bean and pea weevil.

How is the development going

Four-spotted weevil

Grain crops multiply in warehouses or in the field continuously. They lay their eggs on seeds or open beans. They are very firmly attached to them and become hard. Often they can be seen on the container or bags in which the grain is stored. After pests appear from them, they can mate and lay eggs after 24 hours, their number can reach 15 pieces. The female weevils are quite fertile and can lay about 100 eggs.

Important! In the hot season, the egg-laying time is 5 days, and in winter it can be just over a month. The embryo develops within 5-12 days depending on temperature.

The larva of the four-spotted insect has 4 instars.Before it pupates, it breaks the seed shell, forming a hole through which a bug emerges. The time spent in the larvae stage depends on the temperature. If it is high, the period can last about 11 days, and if it is low (16, 8 ° C) - up to two months. The development of the pupa of the four-spotted weevil can take up to six months at low temperatures.

There are 2 types of grains: flying and non-flying insects. As the temperature rises, the amount of the first species increases. Four-spotted beetles are very harmful to crops. Up to 10 larvae can be in one affected grain. The four-spotted weevil loves heat, is a daytime insect and shows its activity in good sunlight. Some types of grains can develop not only on cultivated legumes, but also on malvaceous, convolvulcidae, umbrella plants and other plants.

Pest control

Four-spotted weevil

As soon as the four-spotted kernels are detected, quarantine is announced. But first you need to take preventive measures, which are as follows:

• monitor imported products;
• prohibit the importation of a new infected party into the country;
• conduct a survey of warehouses and warehouses.

If there are grains, a quarantine is imposed. After that, they must be destroyed. There are chemical and physico-mechanical methods of dealing with them. The first involves the use of drugs containing phosphines (hydrogen phosphide). The second - destroy pests using the process of cooling the grain. In order for the grain not to become infected, it is necessary to keep storage rooms and storage facilities clean and in proper condition.