Who is a barn weevil and how to deal with it

Since ancient times, people have found miniature pests in their barns for storing crops. In the 21st century, nothing has changed, so the question: how to deal with the grain weevil is still relevant. After all, this insect is found almost anywhere in the world where cereals and other edible crops are grown. In addition, it easily takes root in residential premises and special storage facilities.

How to deal with a barn weevil

No matter what they say, chemical treatment remains one of the most effective ways to combat weevils. It is carried out by special organizations by processing grain and premises with certain preparations. Most often, two methods of disinfection are used:

1. Aerosol. It consists in spraying the premises with insecticides such as Karate, Actellik, Fufanon, Arrivo.
2. Gas. Special pills are placed in the grain, neutralizing pests, or fumigated with gas. Alfos, Fostoksin, Foskom, Magtoksin are used against the weevil.

Aerosol disinfection is more suitable for grain intended for sowing for the next season. The crop processed in this way cannot be sold for a long time, but it will be well preserved until spring.

Since people learned to grow grain, they have had problems with pests in their stocks. So, even the ancient Egyptians and Romans with displeasure found beetles in their granaries, which spoiled their food. These nasty cosmopolitan insects still pose a threat to barns around the world.

Let us consider in more detail what a barn, aka grain, weevil is. Like all beetles, the weevil belongs to the order of coleoptera. It got its name from the characteristic shape of the head. And this is not without reason: at the end of the so-called rostrum there is a gnawing type of mouth apparatus, with the help of which the pest is introduced into the soft parts of the grain.

The barn weevil is one of the most dangerous grain pests during storage. He eats barley, rice, wheat, buckwheat, corn and even pasta. The beetle can lead to a massive loss of grain storage reserves. Farmers consider its appearance to be nothing more than a disaster, because this little bug can cause irreparable damage to the grain harvest. Therefore, in this article, we will talk about how to deal with a weevil in grain.

Everyone who grows and stores cereals is faced with the question of how to deal with a weevil in grain. This insect has been known since ancient Egypt.

Small yes remote bug

The insect got its name from its unusual head shape. Its front part resembles an elongated proboscis. With its help, the bug destroys the dense skin of grain or cereals.

In the natural environment, there are many types of weevils that destroy:

• grain crops;
• peas;
• buckwheat;
• rice;
• corn.

Therefore, the question of how to deal with the grain weevil is decided at the state level. Otherwise, the country may lose the harvested crop and there will be famine.

The beetle belongs to the Coleoptera family. Its maximum size is approximately 4 mm. The weevil is colored dark brown. Doesn't fly. The cycle of active existence of an adult lasts approximately 2 years. The female hatches 3 or 4 generations in a year.Inside the grain, she lays eggs, where they go through all stages of development.

For individuals to come out, adult beetles gnaw a hole in the grain.

She can lay about 300 eggs per season, which can damage large amounts of grain. Mass reproduction of pests leads to an increase in the temperature of the stored crop. The pest hibernates inside the grain or in various crevices of the room.

Morphology

Imago. The body length of the beetle is from 3.5 to 4.5 mm. Body sizes vary greatly (depending on the food on which it developed). The body is narrow, cylindrical, and shiny. Young beetles are light brown, old ones are almost black.

The small head is extended into a long thin rostrum, at the end of which the mouth organs of the gnawing type are placed. Antennae are curved at an angle.

Pronotum with coarse oblong fossae, upper wings with deep longitudinal grooves, fused. Lower membranous wings not developed - the beetle cannot fly. [6]

The abdomen of the female is straight in profile; anus in the form of a straight transverse slit. In the male, the last segments of the abdomen are curved downward and the anus is in the form of a curved slit. [8]

Egg. The newly laid egg is transparent, off-white, of the correct ellipsoidal shape; over time, this correctness disappears. Its length is 0.6-0.75 mm. Width - 0.3-0.4 mm.

The larva is legless, fleshy, worm-like, about 3-4 mm long, white, with a brown head.

Doll. It resembles an adult beetle in shape, white transparent, 3-5 mm long. [8]

Characteristic

The barn weevil is also called grain. This is an insect whose body does not exceed 5 mm. The size of the bug depends on the food that it consumed during its development. The shape of the body resembles a slightly tapered cylinder, the surface is shiny. The color of the broadbull depends on its age. So, young individuals are colored light brown, while adults are almost black in color.

Barn weevil

The head of the weevil is very small, stretched forward into the rostrum, at the end of which the mouth apparatus is located, with which the grain weevil gnaws its food. The antennae located on the head are curved. The insect has wings: elytra with deep longitudinal furrows, membranous wings.

Interesting!

Despite the fact that the barn weevil is "equipped" with wings, it moves only with the help of its legs, since the development of the wings does not allow them to be used for these purposes.

Life cycle

The beetle is gluttonous and omnivorous, it infects any grain and legumes: rice, buckwheat, wheat, beans, peas, etc. The greatest damage to food is caused by its larva. This pale, worm-like creature is 3-4 mm long. On the anterior segment of the body, it has short legs and a head equipped with mandibles.

Having barely hatched from an egg, the larva immediately bites into the grain and eats it almost to the shell.

Depending on the temperature, the larva is engaged in its destructive activity from twenty days to three months, after which it pupates in a chamber, which it makes in advance and clogs it with its excrement.

In the state of the pupa, the insect can also spend different times - from one week to three.

The pupa resembles an adult beetle: it has six legs, thin wings, and reduced elytra; by the way, growing up, the beetle cannot fly. Having matured, the insect gnaws at itself a way out and leaves the grain in which it developed.

Sexually mature beetles (adults) also damage grain reserves. Their life expectancy is quite significant - up to one and a half years. Considering that a female weevil can lay up to 250 eggs, one can imagine the damage this beetle inflicts. An adult has an oblong body with a length of 3.5 to 4.5 mm. The chitinous cover of juveniles is light brown; it darkens with age.

Sexual dimorphism is weakly expressed: in the female, the abdomen is straight, and in the male, the abdominal segment is bent downward. Gnawing a hole in the grain, the female lays one egg at the bottom, and so many times in a row. The egg chamber is covered with a thin film on top. This is hardened mucus. After a week or two, the larva hatches from the egg, and the life cycle of the pest repeats.

The rape sawfly is only 6-8 mm in size, but it can destroy the entire cruciferous crop. Read more about this insect here.

In the warm season, the beetle begins to reproduce. With the help of a thin proboscis, the female gnaws holes in the grain and lays an egg there. After that, a cork of flour closes the gap. In this way, the infected kernels remain externally intact. You can distinguish them only if you throw the grains into the water: those in which the larva has already settled will float up, and the whole ones will sink to the bottom. Also, on examination, you will notice that the damaged grains are dull in color.

One female can lay 150-300 eggs. Females live 3-4 months, males - 5 months. The period of larval development is 3-6 weeks, depending on temperature and humidity. At a temperature of 4 ° C, the larvae stop developing, and at -5 ° C they die. The larvae turn into transparent pupae up to 3-5 mm long. After 8-22 days, already formed beetles gnaw through the exit from the shelter and go outside.

The barn weevil absorbs a lot of feed, it is ready to use a variety of products: rice, beans, wheat, peas, oats, buckwheat and much more.

The greatest harm is caused by the larva of the granary beetle. This light worm does not exceed 4 mm in din. In front it has legs and a head with mandibles.

The female makes a clutch inside the grain, covering the exit hole. The clutch is large enough: laying eggs, one female can spoil about 300 grains. The eggs develop for about 2 weeks, after which the larvae appear. Young growth continues to develop in the same grain, completely gnawing it from the inside.

Due to the fact that the development of the beetle takes place inside the grain, it can be very difficult to fight it.

Barn weevil larvae

Development

Imago. The female gnaws a shallow hole in the grain, usually near the embryo, at the bottom of which one egg is laid. Fertility of a female weevil is about 200-250 eggs.

Egg. To protect it from drying out and predators, the laid egg is laid with mucus, which quickly hardens in the air.

Larva. A few days later, a legless white larva emerges from the egg, shortened, with a strongly convex back and a brown head. The larva immediately after hatching from the egg bites into the grain, where it spends its entire life, eating up almost all of its contents. In places of feeding, the larvae that have completed development form a cradle, in which they turn into a pupa, in shape resembling an adult beetle.

Doll. Pupal development lasts 7-22 days (depending on the air temperature).

Imago. Beetles of the new generation, after the outer cover has hardened, in 2-6 days gnaw a round hole in the grain shell and come out. They feed by gnawing the softest parts of the grain, which spoil a significant amount of grain during the entire life period. The beetle avoids illuminated areas. At the slightest concussion, he falls into a daze, tightly presses the antennae and legs to the body. [6]

Abiotic factors. Optimal conditions for the development of weevils in grain are grain moisture content of 14 -16%, air humidity 75 - 95% and a temperature of about 25 ° C. The duration of development of the pest from the moment of laying the egg to the imago depends on temperature and humidity. So, at 17 ° C, development lasts about 80 days, at 20 ° C - 70 days, at 25 ° C - 34 days and at 28 ° C - 1 month.

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The life span of the beetle is very significant.At room temperature and in the presence of food, the beetle can live for more than a year (at a temperature of 10-12 ° C - 28 months). [1] At a temperature of (5-10) ° C, the beetles stop feeding, and at 3 ° C, they fall into a cold torpor; at temperatures below 0 ° C, weevils gradually die. [6]

The lack of moisture inhibits the development of the weevil, and the moisture content of 11% is detrimental to it.

In the southern regions, in the conditions of granaries, the barn weevil can give 2-3 generations during the year, and in the central ones - 1-2. Beetles, larvae and pupae overwinter inside the grains. Beetles can also hibernate in crevices and cracks in floors, walls, underground and other similar places. [five]

It is distributed with all types of damaged products. Especially often with warehouse equipment, grain cleaning machines, not cleaned from the remains of old grain, and not destroyed by bills and unusable grain waste. [6]

Advantages and disadvantages

The weevil is a creature extremely adapted to the changing conditions of the external environment. It feels comfortable in a temperature range of 16 to 28 degrees, but can withstand more extreme temperatures. It is also not picky about the humidity of the environment, since it spends most of its life inside the grain under the protection of its dense shell - exine. However, too dry air is destructive for most insects, including the weevil.

The duration of the beetle's life cycle depends on external conditions: the softer they are, the faster the insect reaches sexual maturity. If the temperature regime does not suit him, then the pest is able to fall into suspended animation, in order to then return to a full life. Thus, the pest is capable of producing 2-3 generations per year. Both beetles and larvae hibernate inside the grains. Also, adult insects feel good in crevices, cracks and other secluded places.

Together with the damaged grain, as well as with the equipment, weevils wander from one storehouse to another, affecting agricultural products.

Since a person is forced to endure the presence of a weevil in his barns, he has developed a strategy to combat this pest. For prevention, the following means of struggle are used:

• cooling or, conversely, warming up grain and products of its processing before storage;
• drying it out, because insects are critical to the humidity of the environment;
• cleaning grain from debris and impurities;
• cleaning of storage facilities and treatment by means of disinfestation. For this, preparations based on hydrogen phosphide (phosphine) are used, which are sprayed or used in the form of an aqueous solution;
• the use of ionizing radiation is at the stage of development and, possibly, will be used in the future.

Weevil starts not only in barns, but also in our home. To ensure that the beetle does not spoil our stocks, there are proven and harmless methods:

• place the cereal in the freezer for a while, and then pour it into airtight containers;
• since the insect does not tolerate pungent odors, you can put peeled garlic cloves, bay leaves or lavender sprigs in the cereal;
• cabinets where you store supplies should be washed with soap, soda or vinegar solution and ventilated well.

And, finally, you should not store cereals and pasta half your life ahead: the fight against a harmful beetle can become too long and exhausting at home.

Preventive measures

If there is no desire to coexist with weevils, several rules should be followed:

1. Do not store food in cardboard boxes or plastic bags. Buy special utensils for bulk products.
2. Put a bag of salt in the container where the cereals are stored. It will absorb excess moisture.
3. Place citrus peels, garlic, cloves on the shelves. The pungent smell will scare away "uninvited guests".
4. Put nutmeg and bay leaves in a container with cereals.

The following measures are suitable for residents of private houses:

1. Plant garlic and onions around fruit crops. Weevils do not tolerate the pungent odor of these plants.
2. Avoid planting raspberries and strawberries nearby.
3. Loosen the ground from time to time.

In order not to collide with an elephant in an apartment or house, before buying cereals, check its production date and carefully examine the goods for traces of insects.

Store flour and bread in the refrigerator. At this temperature, insects simply will not survive.

To prevent the appearance of a weevil in a summer cottage, dig up the ground and treat the plants with chemicals.

If you follow the preventive measures, then there will be no one to fight with.

Still have questions? Watch a video on the topic.

Harmfulness

The barn weevil is one of the most dangerous and widespread grain pests.

When feeding, an adult beetle (imago) damages various grain and its processed products. Larvae can develop in wheat, rye, barley, oats, rice, corn, buckwheat, millet, sometimes in pasta and caked flour.

Grains damaged by a weevil become easily accessible to other secondary types of stock pests - insects and mites. The grain damaged by it, in the case of a large amount of weevil, is unfit for food and causes indigestion. [6] Severely infected grain becomes hygroscopic and undergoes further self-heating and rotting. [1]

Killing a beetle in kitchen supplies

How to deal with such a dangerous pest as the barn weevil? How to get rid of such a small but harmful insect in the barn and in the kitchen? In the context of home supplies, when a weevil is found in cereal, the latter should not be eaten, because the secretions of insects and larvae contain carcinogens. The contaminated products must be thrown away, and a tough and, possibly, long-term struggle must be entered into with the weevil.

Weevil control chemical methods

Since it is quite difficult to get rid of the weevil in the grain, it is more advisable to regularly carry out preventive measures:

• before pouring the crop into special storage bins, it is necessary to clear it of grain and weed impurities;
• grain of different harvest period and moisture content should be stored separately;
• containers for storing crops should be thoroughly cleaned before using them from previous supplies and debris;
• you need to monitor the moisture content when storing grain; for long-term storage, humidity should be 2-4%;
• be sure to destroy damaged grains.

It is very difficult to destroy a pest in warehouses, because it is difficult to diagnose it: the insect is located in hard-to-reach places and inside the grain. Control measures will help get rid of the barn weevil, which are as follows:

• Grain cooling down to -10 ° С. In this case, you should monitor the humidity and ventilation of the room. In this case, the pests will be destroyed due to the low temperature, which they cannot tolerate.
• With the help of aspiration preparations and removal of the weevil on sieves with holes. Moving the crop negatively affects the condition of the pest and reduces their number.

Chemical disinfection of grain reserves has become an effective method of exterminating the insect. There are a sufficient number of drugs that can be used to treat the crop from the pest: for example, "Actellik", "Arrivo", "Karate" or "Fufanon".

• the beetle is scared off by garlic and its husks, placed in containers with cereals;
• you need to store cereals in hermetically sealed jars or containers;
• contaminated foods should be thrown away, as they are no longer suitable for food;
• the cabinets are treated with soap-vinegar solution;
• bay leaves and lavender on the shelves repel insects with their scent.

You should not make large stocks of cereals and pasta.Even if you buy cereals in bags, the insect can easily chew through the packaging and get inside. The barn weevil, or the elephant beetle, is capable of causing great damage to the crop, which is stored in warehouses and barns. But still, there are ways to deal with it and bring positive results.

• Preparation of storages before receiving and placing grain for storage: cleaning and subsequent disinfestation by means of wet or aerosol processing; comprehensive examination of all objects for contamination.
• Grain preparation: drying grain to a state of dry or medium dryness, cleaning from impurities and broken grains; maximum decrease in grain temperature; spraying grain contact insecticides.
• Insect and mite infestation should be monitored continuously. [7]

Physical and mechanical methods of pest control of grain stocks:

• Cooling of grain, products of its processing, etc.
• Heating grain, products of its processing, etc.
• Cleaning of grain, products of its processing, etc.

Cooling of grain and products, as well as heating of grain under the established regimes leads to the death of pests, and cleaning ensures a decrease in infestation.

Chemical methods of struggle

I. Preparations based on hydrogen phosphide (phosphine)

II. Contact action insecticides

Grain is treated in the process of moving with aqueous solutions of drugs or directly with emulsion concentrates.

One of the important conditions for preventing the contamination of grain and products by pests at enterprises is good condition and cleanliness of warehouse and production facilities.

It is necessary to get rid of the weevil in the grain in the kitchen immediately, since it can infect other foods. If a package with grain is found in which a barn weevil lives, such a product must be thrown away. Immediately after that, in order to avoid contamination of other products, it is necessary to put into practice the knowledge of how to deal with a bug at home.

The "indoor" barn weevil in the photo looks quite peaceful, but in fact it is able to spoil all the products in the house. He loves rice the most, but the wheat aroma will also attract him. To get rid of an insect, there are several methods based on the characteristics and preferences of the beetle.

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Barn weevil in the house

Before dealing with the barn weevil in the grain, it is necessary to sort out all the loose ones in the cabinet.

If a weevil is found in any package, it must be thrown away, since the larvae secrete a substance that can cause poisoning.

• Knowing at what temperature the weevil dies, they can be destroyed by frost. To do this, those cereals that were close to the spoiled packaging must be put into the freezer for 48 hours (in winter, they can be thrown out onto the balcony).
• The weevil will not be able to survive at temperatures above 50 degrees, so grain and other foods can be heated in the oven by setting the temperature to 60 degrees.

Warming up / freezing food is too early to stop. Further control measures will be as follows:

• Place food in airtight containers, keep tightly closed. Knowing what foods a weevil likes, it is easy to understand what smells attract this insect. Therefore, rice, buckwheat and wheat should be packed especially carefully;
• Place a clove of garlic (peeled) in a container with grain - the parasite does not like this smell;
• Place bay leaves or lavender in cabinets - the weevil also does not tolerate them;
• Regularly wash cabinets, headset walls, shelves with soapy water. Treat dry surfaces with slightly diluted vinegar.

It is important not to stockpile large quantities of food, as this can damage large quantities of grain at once. And it will be much more difficult to destroy an insect in large quantities.

Insecticides against barn weevils are not used at home, since these agents harm products, and the poison may not reach the insect.

It is not so difficult to get rid of a pest at home, but to destroy it in barns and warehouses, chemical agents are used for barn weevils. The only reliable means today is disinfection (aerosol or gas). Only organizations that have the necessary permission, equipment and drugs can poison the weevil.

In order to poison the beetle, pills are often used: "Photoxin", "Magtoxin", "Phallus" and the like. Such processing of premises should be regular - once every 6-8 months. In this case, getting rid of the beetle will be quick and easy.

Garlic, peeled from the husk and placed in containers with cereals, has a frightening effect on the barn weevil. For preventive purposes, cabinets where food products are stored must be treated with a soap-vinegar composition. On the shelves, you can lay out bay leaves and lavender, the smell of which the weevil does not perceive. You should not make large cereal stocks, it is better to purchase products as they are used.

It is very difficult to get rid of the barn weevil in warehouses, because the insect hides in hard-to-reach places, and being inside the grains, it is practically invulnerable and can destroy from 10 to 30% of the harvested grain.

The fight against the barn weevil consists in the following measures:

• Strong cooling of grain (up to -10 ° C), which can be used both for preventive purposes and in the process of exterminating existing pests. Cooling is carried out in dry weather with aeration and ventilation. This requires mandatory control of humidity.
• Part of the barn weevil can be removed by removing it on sieves with holes or using aspiration preparations. Any movement of the grain mass negatively affects the state of harmful insects, reduces their number and development.

One of the effective methods of getting rid of the granary weevil is chemical disinfection of grain - a radical measure consisting in aerosol or gas treatment. Aerosol disinfection is carried out using drugs "Aktellik", "Karate", "Fufanon", "Arrivo". This treatment, the advantage of which is the high efficacy of the drug, is carried out by special organizations. The disadvantages of this method include a long period of time before allowing the sale of grain.

Gas disinfection is carried out by such preparations as "Foskom", "Alfos", "Fostoksin", "Magtoksin". Previously, the room must be carefully sealed, and fumigation should be carried out with the involvement of specialized organizations.

Boldyrev V.F., Bukhgeim A.N., Popov P.V. And others. Fundamentals of protection of agricultural. plants from pests and diseases, part two. - Moscow: state publishing house of collective and state farm literature Selkhozgiz, 1936. - 736 p.

A.A. Goryainov Barn pests and control of them. - Moscow: publishing house New agronomist, 1924. - 120 p.

Instructions for the control of pests of grain stocks. Part 1. - M., 1992 .-- 120 p.

Maslov M.I., Magomedov U.Sh., Mordkovich Ya.B. Fundamentals of quarantine disinfection: monograph. - Voronezh: Scientific book, 2007 .-- 196 p.

Osmolovsky G.E., Bondarenko N.V. Entomology. - L .: Kolos, 1980 .-- 358 p.

Sokolov E.A. Pests of stocks, their quarantine significance and control measures. - Orenburg: Printing House "Dimur", 2004. - 104 p., Ill .: 28 p.

Feidengold V.B., Alekseeva L.V., Zakladnoy G.A. and others. Measures to combat grain losses during harvesting, post-harvest processing and storage at elevators and grain-receiving enterprises. - M .: DeLi print, 2007 .-- 320 p.

B.V. Yakovlev General entomology.- M .: Higher school, 1974 .-- 272 p.

Is it possible to get rid of the pest without the use of chemicals

The life cycle of a beetle lasts up to 5 months, during which time it lays up to 300 eggs. Females gnaw a grain, hide an egg there and close the course with a flour plug. Growing up, the larvae completely eat away the grain from the inside, leaving only a shell. In less than a month, the younger generation emerges from the devastated grain and continues to spoil the remaining stocks. Up to 4 generations of insects can grow in a granary per year.

If the pests have not yet managed to infect most of the grain, you can try to carry out the following measures:

1. In winter, in dry weather, ventilate the warehouses so that the room temperature drops to -10 ° C, controlling the humidity.
2. Sift the grain on a sieve or move it with aspiration preparations.

If a weevil is found in the croup, it is advisable to discard the infected product and immediately address the question of how to deal with the invasion of these insects. If this is not done in time, then with its gnawing mouth organ, the pest will easily overcome such an obstacle as the shell of the bag and make its way to other cereals.

In an apartment, a weevil most often infects rice, therefore this parasite is also called rice. It settles in the croup and after a certain period of time, gnaws the shell and gets out. Thus, in the kitchen we see already adult insects. But even in this case, getting rid of them is quite easy - it is enough to take into account the peculiarities of their existence and apply the simplest means.

If weevils are found in the kitchen, you should first carefully sort out all bulk products.

Since weevils do not tolerate cold, you can get rid of them in the kitchen by freezing them. For this, cereals, in which the beetle was not found, but at the same time they were next to spoiled products, are placed in the freezer for two days. If the infection occurred in winter, then the grain can be taken out to the balcony.

It has been established that the weevil dies when the temperature rises to 50 ° C, so if freezing cannot be applied for some reason, then the beetles can be removed in another way. Place the cereals in the oven and heat them at 60 ° C.

But the fight against the weevil does not end there. Further steps will be as follows:

• after warming or freezing cereals, they should be distributed in glass or plastic containers and sent for storage under a tight lid;
• you can put one peeled clove of garlic in the same containers - its smell remarkably scares off the pest;
• spread lavender flowers or an ordinary bay leaf on the shelves of kitchen cabinets and cabinets - these plants are repellents;
• periodically wash the shelves and inner surfaces of the walls of the kitchen set with soapy water, and then wipe with a weak solution of vinegar.

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And don't overdo it too much.

If in a kitchen very simple measures are used to combat weevils, then chemical preparations are often used to treat warehouses and barns. For many years, disinfection remains a radical measure for destruction, which can be gas or aerosol. Moreover, the processing is carried out not on their own, but exclusively by special organizations that have permission to do so.

Disinfection using aerosols is used both inside warehouses and in areas adjacent to them. In this case, preparations for combating weevil in grain can be as follows:

• Actellik;
• "Karate";
• "Arrivo";
• "Fufanon".

And other pyrethroid and organophosphate insecticides. At the same time, to combat the parasite in the adjacent territory, the rate of the drug is approximately doubled.

But the best results are shown by gas disinfection. To carry it out, they use ethyl bromide gas or tablets that very successfully help get rid of the weevil in the grain:

• "Phallus";
• "Fostoxin";
• Degesh Plates;
• "Foscom";
• Magtoxin.

Before processing, the room is subject to mandatory sealing, and fumigation is carried out by special teams using appropriate equipment.

Recently, the use of ethyl bromide is increasingly being abandoned, since it has been established that it adversely affects atmospheric ozone. Instead, it is recommended to use Phosphine tablets or powder, which is introduced into the stream with special dispensers. The active ingredients of the drug react with moisture and release vapors that are toxic to parasites.

The grain does not absorb this poison - only neutral substances remain in it, which are subsequently removed with the help of aspiration. But despite the high efficiency, fumigation is not always used. The feasibility of this method for the destruction of weevils is determined based on the degree of infection.

In the conditions of large barns and other granaries, freezing is also used. But here, again, additional funds are required, so a similar procedure is carried out only for the grain that is considered especially unstable.

The barn weevil lives for 200-250 days, in one day it can destroy up to 0.67 mg of grain. The larva can destroy up to 11-14 mg of grain per day, while gnawing it from the inside. Thus, a large number of insects can destroy huge amounts of crops.

Damaged products are no longer usable and lose their ability to germinate.

The barn (or grain) weevil got this name because of the peculiar shape of the head. On it there is a rostrum with jaws, with the help of which the insect penetrates into the soft parts of the grains.

An adult beetle cannot fly, but it quickly conquers new territories and is unusually voracious. As a rule, it destroys stocks of seeds of cereals and legumes. If there is no suitable food, the beetle is able to eat flour, pasta, coffee, tea. Therefore, it can be started in rooms intended for storing not only grain, but also food products. Removing the pest is very problematic.

Weevil and plant damaged by it

But its larvae pose a great danger. They resemble worms with a body length of up to 4 mm. In the front part of the body there is a head with mandibles (unformed jaws) and small limbs.

After emerging from the egg, the larva penetrates into the inner part of the grain and gnaws it almost to the shell. A cavity is formed, the entrance to which the pest clogs up with its excrement.

The intensity of the destroying activity of the larva depends on the temperature of the environment, and can last up to 3 months. After that, the individual turns into a pupa and can stay in this state for up to 3 weeks. At a time, a female weevil lays up to 200 eggs, thereby infecting up to 200 grains.

The fight against weevils is complicated by the fact that the insect, under adverse conditions, adapts well to changes in the external environment: it can easily tolerate significant changes in temperature and humidity. If conditions are unfavorable, the barn weevil may go into hibernation.

In this state, its vital functions are able to persist for several months. When favorable conditions come for the pest, it will continue its destructive foray into grain reserves.

There are many tips on how to get rid of weevils.

At home, folk remedies are used to combat weevils. The most proven ways to keep food weevil free are:

1. Stocks should be carefully inspected.If signs of the presence of a weevil are found, the products should be thrown away, since the secretions of weevils and their larvae are dangerous to human health. This is the simplest and most proven method.
2. Insects don't like strong odors. Garlic cloves, lavender or bay leaves should be placed in a container with flour products.
3. The barn weevil does not tolerate high and low temperatures. Therefore, grain, flour, cereals, pasta can be kept in the oven at a temperature of 60 ° C, and stored in the freezer. If the food is kept at a temperature of -5 ° C for about a month, the beetles and their larvae will die.
4. Food should be stored in glass or plastic containers with tightly closed lids so weevils cannot penetrate. If traces of weevils are found in one container, you need to check the rest.
5. The cabinets in which the food is stored must be wiped with soapy water or vinegar solution.
6. You should not create large stocks of food that weevils and their larvae feed on.

In industrial and farm conditions, chemical processing of grain and premises for its storage should be done.

The most effective are:

1. Aerosol treatment. This etchant is used to kill insects in empty warehouses and surrounding areas.
2. Gas treatment. The main poisonous substance used is ethyl bromide.
3. Processing in pickling machines.

For gas disinfection, tablets Foskom, Alfos, Fostoksin, based on aluminum phosphide, are used. The disinfection procedure can only be performed by licensed organizations.

After the grain has been processed, it is necessary to monitor the possibility of re-emergence of insects. In winter, the check is carried out after 30 days, in the warm season - after 15.

Alternatively, you can use a microbiological dressing agent and pheromone traps based on a preparation made from zinc phosphide.

Larva and adult weevils

For long-term storage, the planting material is processed in special dressing machines, which apply a liquid preparation to the grains, which forms a protective film on them. Cars are expensive and profitable on large farms. For small farms, you can design a grain dresser with your own hands. For these purposes, concrete mixers, units from washing machines are used.

Traditional methods

Characterized by its small size (about 4 mm), the pest beetle is distinguished by a dark brown, almost black color, a narrow long body and the presence of wings. Such an insect is not adapted to flights, which does not prevent it from successfully moving long distances with the help of a person. The granary weevil travels from continent to continent on ships with industrial grain shipments, on land - by trains and cars. How to get rid of such a dangerous insect?

The process of reproduction of such insects occurs in the warm period: the female in each grain with the help of a thin proboscis gnaws a small hole (two in the corn grain), lays an egg in it, and then covers the gap with a cork from flour. This trick makes damaged grains outwardly almost indistinguishable from whole ones.

The fertility of one individual is 150-300 eggs with a life cycle of 3-4 months; males live a little longer, about 5 months. The duration of development of the larva (about 3 mm long, white, with a brown head) depends on temperature and humidity and is 3-6 weeks. One can only imagine how many thousands of pests can be produced by only one pair of beetles during the year.

At a temperature of 4 ° C, the larvae stop developing, at -5 ° C they die. Upon completion of development, they turn into almost transparent, 3-5 mm long pupae.After 7 - 22 days, the formed beetles of the new generation gnaw out a passage in the shell and leave the shelter to the outside. The average lifespan of an adult specimen is about 2 years.

The most dangerous species

A weevil can cause irreparable harm to absolutely any plant. Most often, a person encounters the following representatives of these pests:

Beet weevil. Damages crops of sugar beet. In the spring, before the first shoots of this culture appear, the beetle feeds on weeds. After the attack by pests of the field, the crops are thinned out, and the roots reduce the sugar content.

Barn weevil. It is considered the most common pest. Pests live inside the grains, first gnawing holes in them. Females lay eggs there - about 200 pcs. into each notch.

Nut weevil. The female damages the green part of the nut, and the larva gnaws the nut from the inside. If the necessary measures to combat this pest are not taken in time, the tree may die.

Weevil is a stone flower beetle. Adult insects feed on leaves and buds, and the larvae gnaw out the inside of the fruit of plum, cherry, sweet cherry, bird cherry. When forming new fruits, the female can easily make a hole in the soft bone in order to lay eggs in it.

Cabbage weevil damages crops such as turnip, cabbage and radish. In accordance with which subspecies the insect belongs to, it can feed on roots, herbs or the fruit itself.