Grain of wide and narrow specialization

Grain - an insect from the same family belongs to the order of beetles or beetles. Typically, these leguminous pests range in size from one to twenty-two millimeters.

some weevils develop on umbellate, Asteraceae or bindweed plants, but we will not consider them in view of their small harm to agricultural production.

The photo shows a four-spotted caryopsis, it is not a resident of the Russian Federation, but can be imported with legumes from neighboring countries, mainly from Central Asia.

Beetle species

Among the variety of grains, several beetles especially harmful to leguminous plants stand out:

• bean;
• pea;
  
• Chinese
• four-spotted.

If the Chinese grain, like the four-spotted one, is only a quarantine pest, sometimes imported to us with legumes from China, then the other two species have long settled in our territory. It is about these bugs that we will talk in more detail.

Pea

Pea kernel - a beetle up to five millimeters in length, is a harmful pest of peas, it does not damage other legumes, although it can be nourished on the flowers of wild legumes.

These pests hibernate inside grains, having got together with them in barns or pantries or having developed there from eggs. Part of the insects can overwinter in showered grains directly in the field under cover of old straw, leaves and other plant debris.

In the spring of the caryopsis, pea pests fly over to blooming bean plants and feed on pollen or the rudiments of their fruits, but as soon as they smell the blooming peas, they move to its plantings. There they feed on pollen and flower wings, and when the pods appear, the female lays one small, slightly less than a millimeter, egg in them.

Peas ripen and at the same time a larva develops in the egg. By the time of pea ripeness, the larva bites into the grain and eats out a cave in it, in which it then pupates and then turns into a beetle.

Peas are threshed already with a pest by a weevil, in the pea cavity they usually remain until spring, rare individuals leave their houses in the autumn.

Advice! To prevent such pest infection, it is recommended to sow peas at the earliest possible date!

Bean

The bean kernel is an even more malicious pest than its pea cousin. The fact is that, unlike the previous pest, this one eats all the plants and grains in a row, if only they belong to legumes, including:

• beans;
• Beans
• peas;
• rank;
• Vika;
• lentils.

There is no information on soybeans, and there is enough Chinese grain for it. Most likely, there are simply no long-term observations on this culture. But most of all, beans love this type of grains, for which he got his name.

Bean kernels - a four millimeter long beetle with dark brown hard upper wings. Elytra have bright longitudinal spots.

The development of the insect occurs almost in the same way as that of a pea beetle. At the moment of formation of the beans, the grain is transferred to the beans and, gnawing the connective weave between the leaves, gets into the pod.In one bean, the female lays up to twenty eggs out of a total of one hundred.

Unlike pea larvae, which have the rule: “Each beetle has a separate apartment!”, The beans can climb all twenty into one grain. This is favored by the larger size of the bean compared to a pea, and the smaller size of the larva, only seven tenths of a millimeter.

The development of bean kernels takes place in the storehouse constantly. Beetles mate, lay new portions of eggs, I recall, up to a hundred pieces from one female. Naturally, in the spring, instead of even strong beans, one shell remains, or even dust.

Prevention

Before we talk about methods of controlling bean weevils, let us recall the preventive measures designed to prevent the spread of this dangerous pest, we will start directly from sowing.

• In order not to infect the site with a pest, it is necessary to carefully select the seed material. If there is a large defeat of the grains, it is better not to use them, with a small defeat, the seeds can be placed for an hour in an aqueous saline solution, the density of which is one kilogram of salt in a three-liter jar of water.
• Sowing should be done as early as possible, this will give the plant a margin of flowering before the mass departure of grains.
  
• Before the formation of beans, you can treat the crops of legumes with insecticides, such as Arrivo, Aktara or the like.
• For home storage, after thoroughly sorting the grains, they should be placed in glass or metal dishes. Good storage place will be loggias and balconies with negative temperature in the winter.
• In granaries, preventive treatment of grades should be carried out: cleaning, drying, disinfection.

Fight

The first battle must be imposed on the pest in the garden, if there were cases of its invasion of our territory. This method of control, treatment with insecticides, we have already used for prevention. If nevertheless the pest has made its way, it is necessary to repeat the treatment, and it is best to use a drug with another active substance.

The second battle occurs when a crop infection is detected in the granary. The following control methods will help here:

1. Brine. With the solution already mentioned above, it is possible to process grains if it is a question of harvesting from a small garden or summer cottage.
2. Warming up. A temperature of over sixty degrees in one hour will help in the destruction of insects, although the sowing quality of the seeds may decrease.
3. Freezing. Three days in the cold below ten degrees, and the enemy will be defeated. You can use natural Russian cold or a freezer.
4. Processing with the same insecticides when it comes to storage with a large supply of grain.
5. Fumigation. The most radical way in which the seed is treated with special gases.

To consolidate the read material, look at the plot of the “First Channel” about the right choice of beans in the store. True, the authors and correspondents confuse pea and bean kernels there, but this does not affect the correct purchase of grains.