Bean kernels - a dangerous pest of legumes

Like many other troubles, bean kernels came to us from the American continent. Initially, it spread along the shores of the Mediterranean and its associated seas, where legumes were mainly sown.

It is also important that in the Middle Ages, trade was for the most part conducted and flourished in port cities. Therefore, warehouses and granaries were built along the coast, which also contributed to the creation of an enabling environment for the spread of bean kernels.

The appearance of the bug does not sparkle with colors, although something remarkable can be seen in the photo of the bean kernel.

Close relatives of bean are Chinese, pea and four-spotted grains. But unlike our today's heroine, they are monophagous pests of only one culture.

Reference! According to their nutritional ability, insect pests are divided into three groups. Monophages feed exclusively on one species of plant, oligophages - on several, polyphages - on many different species. Bean kernel on this basis can be attributed to oligophages.

Pest biology

Place in classification and description

Bean kernel is a beetle of the family of kernels specializing in the defeat of leguminous plants. This is a small insect half a centimeter long.

The oval body of the weevil is painted in gray-brown tones and covered with numerous brownish-yellow hairs. Elytra of dark color does not completely cover the body of the insect so that a light abdomen is visible. This property can be considered a feature of this type. There are sharp teeth on the hind legs of the insect.

Spread

As mentioned above, at first beans were spread only along the coast of warm seas. With the expansion of agricultural production and the expansion of trading platforms with numerous warehouses and transshipment points, the area of ​​the pest has also increased.

The introduction of beans and other legumes into the truck gardening has led the pest to our summer cottages. The habit of stocking up cereals and beans paved the way for bean kernels to apartments.

Summarizing what has been written, we can say that this pest is found everywhere where legumes are cultivated or there are large storages with optimal conditions for beetles.

Food

Bean kernels feed on most legumes. Preferring primarily beans, the pest will not give up grains and plants such as:

• fodder and edible beans;
• peas of different species;
• lentils
• Vika;
• rank;
• chickpeas
• soybeans.

When developing, bean grains larvae eat beans and other species completely, so that it is even difficult to use them for food for domestic and agricultural animals.

Lifestyle & Development

In its way of life and development, bean kernels are a very plastic insect. Under optimal conditions, it is capable of producing up to six generations per year. This requires positive temperatures in the range of 18-30 degrees Celsius and a relative humidity of 75-90 percent.

If the habitat of the grains is a field, then the beetles begin to multiply when the beans are ripening, the process does not stop at heated warehouses and living quarters, and each new generation is able to overlap the previous one, combining pests of different ages.

Each female is able to lay up to two hundred testicles of milky white color up to seven tenths of a millimeter in length. And twenty copies can fit on one bean. Oviposition is placed on the inside of the bean flaps or directly on the surface of the grains. In other cultures, the number of testicles placed is proportional to the size of the fruiting bodies.

Egg incubation occurs within one to two weeks, depending on temperature indicators. The emerged larva in the form of a caterpillar 4 millimeters long first has legs that it loses as it grows. She immediately after biting, bites into the grain and feeds until it completely destroys it, after which it moves to the next. After 18-36 days, the stage ends and the insect pupates.

Reference! Bean kernel refers to insects with a full development cycle: egg - larva - pupa - imago.

In the pupal stage, the insect spends an average of 8-11 days, after which metamorphosis occurs and an adult insect appears in the form of a beetle.

According to biologists, the fastest time to generate bean kernels is only 34 days, and two months give a guaranteed new generation of pest.

Malware

The harmfulness of bean kernels lies in its rapid reproduction and mass destruction of the crop. Moreover, even in the fields, until the crop has matured, the beetles are able to feed on various parts of legumes:

• flower petals;
• pollen;
• autonomic organs.

In storages, grains at a favorable temperature are able to leave one trash from the crop.

The second important harmful factor is the omnivorous weevil relative to legumes. Therefore, having brought the pest to a warehouse with one crop, most likely you will give it access to related grains.

Infection prevention

Before you start the fight against bean kernels, you should try to prevent it from your crop by applying preventive methods.

1. The first measure will be the careful selection of varietal material. Sowing with infected grains is unacceptable.
   

   Attention! With a minor infection, extracting the seeds in saline may help. For this, a kilogram of salt is dissolved in three liters of water and the grains are held for at least one to two hours immediately before sowing.

2. Sowing should be done as soon as possible, trying to get ahead of the time of departure of the pest.
3. Insecticidal treatment of crops during the formation of beans will protect the crop by scaring off bugs.
4. Before laying the crop in the storage, it is necessary to carry out its preparation: cleaning, disinfection, drying.
5. you should also carefully look at the pledged grains, rejecting clearly affected grains.
6. At home, you should carefully sort through the grains and place them in a sealed container, such as glass jars.

Pest Control

If nevertheless you have found foci of crop damage, you should apply one of the methods to combat bean grains. If preventive spraying was carried out, but the beetles still made their way to the field, you should use the drug with another active substance.

Infected grains in the storage should be treated with saline according to the above recipe.

Bean kernel does not tolerate low temperatures, and negative ones completely kill it. Therefore, it is better to store grains that are not seeds in the winter in unheated storages, and in regions with a mild climate it is better to specially freeze them. In the conditions of home storage, it is enough to take the beans to the balcony or to the cold pantry.

When storing a large number of grains and in the presence of funds, infection can be stopped by fumigating the storage with preparations based on phosphorous hydrogen, phosphine.

Our help! Fumigation - special gas treatment, carried out in special chambers or under a film.

Also, in storages of grain, beans and other beans are treated with insecticides in two ways of disinfection:

• Humidity: liquid solutions, suspensions, emulsions;
• aerosol: by spraying in the form of the smallest particles of a liquid mixed with air.

We did not find it necessary to frighten our readers with a video clip with disgusting bugs. Instead, look at the plot about the correct preparation of the harvest of green beans for storage, filmed by an experienced gardener Kramarenko.