The most dangerous diseases and pests of forest plantations. Forest pests

Federal agency by education

Fraternal Pulp and Paper College

In the discipline Forestry

Forest pests

FOREST PESTS

Forest pests are organisms that damage various parts, organs and tissues of trees and shrubs. As a result, the growth and fruiting of plants is reduced, renewal and growth are disrupted, they die and damage, especially wood, occurs. The vast majority of forest pests belong to the class of insects; some species of ticks and vertebrates, especially rodents and lagomorphs, are less harmful. Being part of the forest fauna, pests organically enter the forest community. In virgin (natural) forests, their activity does not lead to any destructive consequences and does not harm the existence and regeneration of forest vegetation. But forest pests prevent people from rational use forests, which is why they are also called forest pests. In each ecological and economic group there are mass species that periodically reproduce in huge numbers over a large area and cause significant harm; species of limited distribution that form local foci of mass reproduction; species capable of causing damage, but not potentially harmful in a given area under existing conditions. Based on the nature of damage to forests by pests, they can be divided into two groups: focal (concentrated, concentrated) and diffuse (scattered, scattered) damage. In turn, each of these groups is divided into large-scale and local damage according to the degree of territorial distribution.

The vast majority of tree pests are insects. Depending on the habitat and nature of their diet, the nature of the damage caused, forest pests are divided into specialized groups - pests of foliage and needles (pine- and leaf-eating (primary)), attacking healthy plants; stem (secondary), attacking weakened trees; root, or soil-dwelling; pests of fruits and seeds.

PESTS OF FOLIAGE AND NEEDLES

Needle- and leaf-eating pests are especially diverse and numerous; include representatives of various orders of forest insects that feed on leaves (needles). Foliage and needles are damaged mainly by butterfly larvae (caterpillars), less commonly by sawfly larvae, and in isolated cases by beetles (from the family of leaf beetles) and some other insects. In the larval and adult stages they lead an open lifestyle (only some in the larval phase live inside the leaves), so they are directly influenced by a variety of climatic factors. Some needle- and leaf-eating insects (butterflies, sawflies, weavers) are characterized by large fluctuations in numbers; for others (leaf beetles, elephant beetles, blister beetles, etc.) - more moderate; they form foci mainly in young plantings, parks and shelterbelts. Under favorable conditions, forest pests periodically produce outbreaks of mass reproduction. Each outbreak usually takes 7 generations of pests and consists of 4 phases: initial (the number of the pest increases slightly), increasing numbers (pest foci are formed), the outbreak itself (forest pests appear en masse and heavily eat up the tree crowns), crisis (the outbreak subsides). During an outbreak of mass reproduction, needle- and leaf-eating insects in a relatively short time are able to spread over hundreds of thousands of hectares and cause severe damage to forests, causing loss of growth, severe weakening and subsequent drying out of trees or entire stands. Tree species tolerate crown eating in different ways. The most sensitive to this damage are dark coniferous species - fir, cedar pine and spruce, in which the loss of 70 - 80% of needles leads to the inevitable death of the tree. Scots pine, as a rule, safely tolerates a single complete eating, and larch - twice. Hardwoods are much more resistant.

The reasons for the outbreaks of leaf- and needle-eating insects are still not entirely clear. Needle-eating insects usually do more damage to a somewhat weakened tree stand; this has not yet been proven for leaf-eating insects. Outbreaks or at least increases in the number of many tree pests (for example, gypsy moth, pine cutworm, pine moth, pine sawfly) repeat at intervals of 10 - 12 years and are strictly confined to certain phases of the 11-year cycle of solar activity, but the mechanism of this phenomenon is up to still unknown. In terms of their effect on plants, sucking insects - aphids, coccids, psyllids, etc. - are in many ways similar to leaf-eating pests.

In the pre-war years, in a number of regions of the Republic of Bashkortostan (Kugarchinsky, Buraevsky, etc.), the caterpillars of this pest, having destroyed the foliage of trees, moved to grain fields. Over the last century, outbreaks of its numbers have been observed at least 10 times. In 1961, over 250 thousand hectares of plantings in the republic were damaged by the gypsy moth. A strong outbreak in the number of this species was also noted in the late 70s. The butterfly flies in July-August. Eggs laid in the butt part can withstand frosts down to 60 o. WITH

Gypsy moth

Among these pests, the most dangerous is the Siberian silkworm (Siberian cocoon moth), a butterfly of the cocoon moth family. This is a large butterfly (females have a wingspan of 60-80 mm, males have a wingspan of 40-60 mm), the color of which varies from light brown to black. Found from the Urals to Primorye. The female lays eggs (200-800 in a clutch) on pine needles, branches and tree trunks. After 2-3 weeks, caterpillars up to 7 cm long appear, feeding on pine needles and overwintering under the forest floor. In the spring they climb into the crown and eat old needles, and in the fall they go back to wintering. In the spring of the third year, the caterpillars feed on the Siberian cocoon moth most intensively and pupate in a cocoon in June. After a month, butterflies emerge from the pupa. Outbreaks of mass reproduction occur after 2-3 dry years and last 7-10 years. Outbreaks occur in forests thinned by logging and fires.

STEM PESTS (XYLOPHAGES)

Stem pests are very numerous and belong to the orders of beetles (mainly bark beetles, longhorned beetles, borers, weevils), hymenoptera (horntails) and butterflies (wood borers, glass beetles). Borers, grinders, etc. are of less importance. As a rule, they lead a hidden lifestyle, only adult insects live openly (in bark beetles they also most of lives are spent inside tissues). They develop under the bark and in the wood of the trunk and branches, gnawing passages in the phloem, cambium and living layers of sapwood (often having a shape characteristic of each species), often causing trees to dry out or lead part of it (branch, top) to die. Many make deep passages in the trunks, depreciating the value of the wood. Such insects pose a formidable danger to forests affected by drought, flooding, fires, gas or dust emissions, leaf-eating pests and other unfavorable factors. Pseudobark beetles, borers, grinders and some other beetles are of incomparably less importance. Mass reproduction depends on the viability of trees, plantings and their sanitary condition. Key Feature stem pests is that they, as a rule, do not settle on healthy trees. Their species can inhabit either weakened, but still living, often apparently healthy trees, or dying or freshly dead trees (including freshly cut ones), or old dead wood. In plantations with poor sanitary conditions or located near areas of mass reproduction of secondary pests, even completely healthy trees are often colonized by them.

Stem pests are very dangerous for artificial forest plantations and plantings in the steppe and forest-steppe zones, which often suffer from a lack of moisture. Control measures are predominantly preventive: forestry measures that increase the biological stability of plantations (creation of mixed crops with undergrowth, selection of species in accordance with local climatic and soil conditions, resistant to diseases and pests, right choice felling systems, compliance with sanitary rules, etc.), timely cleaning of felling areas from

felling residues, etc. It is effective to lay out trap trees in plantations, for which they use diseased and severely weakened trees that have been felled by wind, storm, snow, which attract pests that fly in the spring (a month before the start of summer) and in the summer (immediately before the start of summer or when the first beetles appear). After infestation by pests, trap trees are debarked during the period while the insects are developing under the bark and they have not penetrated either into the wood or into the thickness of the bark, and the bark is burned or scattered in open areas with the bast facing up. Medicinal chemical means of control are beginning to become widespread.

BARK BEETLE STENOGRAPHER

ROOTS PESTS

A significant portion of insects are root pests of forests. The roots of plants are usually damaged by their larvae - the larvae of beetles and other lamellar beetles, click beetles (wireworms), darkling beetles (false wireworms), as well as some other species that live and lay eggs in the soil, where all their development occurs. Adult insects, born in the soil, come to its surface only for additional feeding and mating. Ripe females burrow into the soil again to lay eggs and then die. Most root pests cause particular harm in nurseries and young plantings. The survival, growth, development, and number of root pests depend not only on soil conditions, but also on the characteristics of the vegetation cover. Fluctuations in their numbers are seriously influenced by predatory insects, other soil invertebrates, as well as mammals and birds. Mainly beetles of the family. Lamellar beetles (Khrushchi) and, above all, May Khrushchev most often develop in non-renewed fellings and subsequently make it very difficult for a long time to grow trees on them. Among other lamellar beetles, the June beetle (Amphimallon solstitialis) is noted, damaging the roots of conifers and hardwood. It is common in clearings and clearings of forests

PESTS OF CONES, FRUITS AND SEEDS

These include a wide group of insects (butterflies - leaf rollers and moths, dipterans - flies, mosquitoes, beetles - weevils, etc.) and some other animals that feed on the tissues of the reproductive organs. Biological features These pests are determined by the specifics of the ecological niche they occupy. During the feeding period, they lead a hidden lifestyle and develop in accordance with the phenological phases of the food species. Populations of these pests are formed only in plantings that have entered the period of regular fruiting. Many types of pests have adapted to the conditions of periodic fruiting of trees, i.e. alternating seed years with low-yielding or lean years. A number of species of insects from different families and orders annually destroy a significant part of the cones and fruits on trees (in case of low yields, almost completely). They damage the generative organs of tree species and often cause great damage forestry, thus, significantly hinder the regeneration of tree species. In addition to insects, trees are also damaged by other animals, but their role, with a few exceptions, is small. Mites sucking leaves and shoots cause galls to form on them. In some cases, damage to forest nurseries and young forest crops is caused by mice, voles and hares.

The fight against these pests is difficult, since most of the time they lead a hidden lifestyle inside seeds and fruits.

Pests of nurseries and young trees

The group of pests of nurseries and young animals includes a large number of species that differ greatly in the type of nutrition and the nature of the damage caused, lifestyle and environmental features. Based on their ecological and economic characteristics and lifestyle, they can be divided into two main subgroups: harmful soil-dwelling insects (root pests) and pests of above-ground parts of plants. As young trees grow and develop different types and groups of pests successively replace each other, but can often cause harm together.

Forest protection from pests is carried out through the use of systems of measures carried out under the control and with the participation of a specialized forest protection service. Preventive and exterminatory control measures are used against these pests, which pose a great threat to nurseries, forest crops and field protective plantings. Preventive measures include forestry and silvicultural measures, exterminators include chemical ones (mixing seeds before sowing with insecticides, introducing insecticides into the soil and treating seedlings, saplings and cuttings with them, aerial pollination of plantings against adult beetles, etc.) and some physical and mechanical control measures. In relation to specific cases, systems of measures are developed based on data from special surveys.

LITERATURE

1. Forest entomology, 4th ed., M. - L., 1961;

2. Vorontsov A.I., Biological principles of forest protection, M., 1963;

3. Supervision, accounting and forecast of mass reproductions of needle- and leaf-eating insects in the forests of the USSR, ed. A.I. Ilyinsky and I.V. Tropina, M., 1965;

4. Khramtsov N.N., Padiy N.N., Forest stem pests and their control, M., 1965;

5. Rudnev D.F., Chemicals forest pest control, M., 1966.

6. Vorontsov A.I. Forest entomology, 4th ed. M., 1982; Animal world Bashkortostan, 2 ed. Ufa, 1995; Forests of Russia: encyclopedia. M., 1995.

Every living thing can get sick, and trees are no exception. Their health can be compromised for a variety of reasons, not the least of which is a variety of pests. Sometimes they attack an already weakened tree, sometimes they choose a completely healthy one. Worst of all, pests easily attack one tree after another, and it is not always possible to detect an infestation in time. How to check the condition of each tree in a huge forest? Very often the disease is detected when a significant area has already been affected.

How does mass infection occur and how to determine it?

In order for mass infection to begin, several factors most often need to coincide. Firstly, without pests there will be no infection. Some of them must be present in the forest. These can be a variety of butterflies and beetles, as well as fly larvae, caterpillars and many other tiny animals. The second necessary condition is a favorable situation for the active uncontrolled reproduction of pests. Good weather, a lack or complete absence of natural enemies, the presence of a large amount of food and some other factors will certainly provoke a massive infestation of forests by pests.

So existence favorable conditions is essentially the first stage of infection. Then, once in a favorable environment, the pests actively reproduce. This is the second stage of mass infection. There are more and more of them. On average, this period can last up to three years.

When the pests become really numerous, the second period begins, accompanied by severe damage to the forest. It represents an outbreak of infection as such. This state of affairs rarely lasts longer than two years. In the end, an excessive number of pests leads to the fact that they do not have enough food, diseases spread among them, and more and more predators appear, whose natural prey they are. This period also lasts about a year or two.

To determine whether a forest area is experiencing massive pest damage, special criteria are used, both qualitative and quantitative.

As for the quantitative criteria, they are as follows:

1. Degree of infestation, also known as absolute infestation, which is the number of pests in an area equal to one tree or one square meter soil.
2. The reproduction rate is determined by comparing the number of pests in different periods, for example, last year and the year before. To find out, you need to calculate what the ratio of the more recent degree of population to the older one is.
3. The outbreak growth rate is intended to show how quickly the danger is growing. To determine it, a certain period before the outbreak is compared with the period after it. When calculating the growth rate of an outbreak, one should calculate the ratio of the degree of population during the period during the outbreak to the degree of population in the period before it.

Forest pests in faces

The pine cutworm is an inconspicuous-looking butterfly, brown with white spots, but its caterpillars are elegant - dark green, with snow-white longitudinal stripes. The females lay eggs on the branches, from which caterpillars emerge, diligently gnawing first the young ones, and then all the needles. This can destroy the tree or weaken it. IN the latter case it may be attacked by other pests, for example, longhorned beetles. Natural enemies of pine cutworms are birds that feed on caterpillars.

There are many types of longhorned beetles. Let's take black pine as an example. These are rather elegant black beetles with very long antennae that devour the bark of branches and occasionally pine needles. To lay eggs, they prefer to choose trees that have been weakened in some way. The larvae, once born, are, as a rule, quite capable of finishing them off.

The blue borer, a beautiful dark blue beetle with a tint of black or green, also infects pine trees, preferring weakened ones, and lays its eggs in cracks in the bark. The four-spot borer, a pleasant-looking brownish-golden bug, behaves in exactly the same way.

How to fight forest pests?

Nowadays, there are several methods of pest control, and each of them is necessary in its own way.

To prevent mass infections, there is a forestry method. It consists of carrying out a number of preventive measures that are highly likely to prevent infection. If the seedlings are healthy, the ecological situation is stable, and monitoring is constant, it will be more difficult for pests to infest the area.

The physical and mechanical method of control consists in the timely destruction of pests using, so to speak, brute force. Good example- collecting pine cones affected by tar before the larvae turn into beetles.

The biological control method requires a competent approach, but the difficulties are often worth it. It allows you to force nature itself to fight pests. For example, natural enemies of a particular pest are taken and they are given the opportunity to hunt properly. Of course, ideally, these natural enemies should already live on the site, but the population may be insufficient or even absent. If there are a sufficient number of such animals, they should be protected as much as possible so as not to encounter mass infection due to the lack of predators. You can also purposefully infect pests with various diseases, for example, the marsupial fungus can destroy most of the population of nun silkworm caterpillars.

The most dangerous and radical method of pest control is chemical. It should be resorted to only in extreme cases, when the infection is so great that other methods no longer help. The affected areas are treated with pest-killing substances. Unfortunately, they, as a rule, kill not only pests and have an extremely bad effect on the environmental situation.

Man is conquering more and more territories from nature. In this struggle he is confronted by an army of pests: insects, microorganisms, animals. Expecting a high harvest, we sometimes unexpectedly encounter a huge number of uninvited guests in the field, in the garden, in the garden. It is too late to fight pests while they are destroying our crops. It is best to take care of prevention.

Pest classification

Agricultural pests are divided into:

• Insects.
• Microorganisms.
• Worms and slugs.
• Animals.

Pests are divided on a territorial basis. They may be characteristic of your region or present in gardens and vegetable gardens everywhere. Certain pests, most often microorganisms, are characteristic only of greenhouses. According to the type of damage, enemies of agricultural crops are divided into:

1. Pests of the root system.
2. Eaters of leaves and stems.
3. Pests of ovaries and buds.
4. Fruit destroyers.

Microorganisms

Microorganisms are airborne or introduced through damage caused by other pests. There are obligate microorganisms that do not exist outside the plant, and conditionally phytopathogenic microorganisms that can live in other environments. The first group is dangerous because, being unable to exist outside the host, it uses its full potential, significantly weakening agricultural crops. The second form can be transmitted over long distances and cover large areas. Just like insects, garden pests are highly specialized in one group of plants. Damage to plants is caused by:

Among plant pests, the class of worms includes nematodes, which mainly attack roots. Slugs are content with leaves and shoots. There are many folk remedies fight them. The slug is noticeable in the garden, and the damage from its activities is also noticeable. This gave rise to a lot of signs. Slugs belong to the class of gastropods. More than anything else in the world, they love ripe strawberries. A snail is the same as a slug, only with a shell. It can eat leaves of cabbage, cucumber, horseradish and other plants. When a leaf is damaged, pathogenic microorganisms are introduced and the process of photosynthesis is disrupted. The plant is forced to compensate for their growth by fruiting.

Rodents cause great damage to agricultural crops. They damage both roots and fruits. There are cases of crop damage by large flocks of birds.

Insects

In order to understand which insects are considered pests, it is necessary to classify them. Many of them participate in plant pollination, destroy fungi, and improve soil composition. Although damage can be caused not only by phytophages, all insect pests of fields and vegetable gardens are divided by type of feeding:

1. Monophagous - they eat only one type of plant, one type of fruit: pear moth, Colorado potato beetle.
2. Oligophages eat plants of the same family: cabbage moths, for example.
3. Polyphages eat everything, including cabbage cutworms and locusts.

Variety of insect pests

Agricultural pests are found among many orders:

• Springtails - more than 2000 species have been discovered, are extremely resilient, live in damp places, feed on mold fungi, sometimes undermining young plant growth.
• Hemiptera - more than 40,000 species have been identified, all of them feed on plants, sucking juices and leaving a sugary coating on the leaves that interferes with the process of photosynthesis. Plants are often infected with viral diseases. The most famous representatives: cicadas, psyllids, aphids, bugs, scale insects.
• Thrips - no more than five thousand species. The order is divided into two suborders, representatives of one of which are phytophages, and the other are predators that destroy smaller pests.
• Hymenoptera - includes the sawfly and horntail families. They damage forests and forest plantations. Typical representatives are pine sawfly and birch horntail.
• Diptera are represented by flies and mosquitoes. Some representatives perform the important function of pollination. Onion and daffodil flies damage the vegetable garden and flower bed.
• Lepidoptera, or butterflies, do not harm plants themselves, participating in pollination. The deposited larvae destroy parts of the plant. Represented by families: cutworms, moths, white moths, willowworts, corydalis, cocoon moths, ermine moths, carpenter moths, glass moths.
• Orthoptera are an extremely numerous order, numbering more than 20,000 species. Among them are the most dangerous pests, for example, locusts. These voracious insects are pests of fields. Locusts are capable of flying over vast distances and gathering in huge swarms. Mole crickets are no less dangerous; when they appear in the garden, they also massively destroy young shoots.
• There are 250,000 species of beetles or Coleoptera. They not only destroy parts of plants, but also affect crops in barns and can cause illness in domestic animals. It is worth mentioning not only what insect pests exist among beetles. Most Coleoptera are predators, feeding on their classmates. Some are beneficial by destroying dead organic matter, like the dung beetle. Beetles are divided into many families. Predators include ladybugs and ground beetles. Forest pests include longhorned beetles (oak, poplar, willow), lamellar beetles (chafer beetle, beetle, scale insects), and bark beetles. Pests of agricultural crops are weevils, tubeworms, borers and click beetles. The main enemies of the fields are leaf beetles, including the famous Colorado potato beetle.

Forest pests

Pests can also be classified according to the objects they harm. Forest pests damage trees and shrubs. They especially harm forest plantations and young growth, parks and nature reserves. They are divided into leaf-eaters and those that feed on needles. Damage to forest areas by pests in the area Russian Federation ranges from 0.1% to 25-29% of the total forest area. As an example, the following list shows the maximum damage to forest areas in the European part of Russia, which was occupied by forest pests, for the period from 1977 to 2000.

1. Gypsy moth - 2063.72 hectares.
2. Green oak leaf roller - 1103.28 ha.
3. Goldtail - 412.2 ha.
4. Siberian silkworm - 0.89 ha.
5. Pine silkworm - 30.18 hectares.
6. Silkworm nun - 66.29 hectares.
7. Pine moth - 40.22 ha.
8. Pine armyworm - 30.97 ha.
9. Red pine sawfly - 113.50 ha.
10. Common pine sawfly - 42.26 ha.

The scale of reproduction depends on external conditions and the type of pest. The burst of increase in numbers lasts seven generations. There are 4 phases, during which growth rates may vary. At the beginning of the outbreak, the growth is insignificant, followed by steady growth and a sharp increase in numbers. After almost all the leaves are destroyed, the increase in the number of insects subsides. The most dangerous are bark beetles, glass beetles, horntails, and wood borers. All of them lead a hidden lifestyle in the trunk, gnawing passages. This leads to damage to the marketability of the wood and drying out of the tree. Forest pests can spread to gardens.

Field pest insects

The biggest damage national economy caused by this type of pest. Among the most dangerous:

Specific crop destroyers

It is difficult to calculate which field pests cause the most damage. Cereals are harmed by grain sawflies, some types of thrips, barley moths, and green-eye moths. Peas and legumes are harmed by aphids, leaf rollers and pea weevils, and gamma metalweed caterpillars. The flaxworm eats not only flax, but also peas. Hay grasses are mainly damaged by cutworms, whose larvae feed on roots and seedlings. Buckwheat is prevented from developing by blizzard and meadow moth. All kinds of leaf beetles cause more damage to garden crops: carrot fly, cabbage moth, cabbage caterpillars and rapeseed sawfly, cabbage weevil. Insect pests of fields and vegetable gardens are numerous. It is quite difficult to mention everyone.

Garden pests

In first place in this group are not codling moths. Although they are undoubtedly dangerous garden pests. Before the crop ripens, buds and ovaries must appear. Numerous insect pests can destroy your garden in early spring. Fruit crops are harmed by:

1. Various weevils and tubeworms that lay larvae in buds.
2. Whiteweeds, willowworts, cocoon moths, damaging leaves.
3. Sucking insect pests: aphids, psyllids, mites.

Tree trunks are damaged by all kinds of scale insects (plum scale, acacia scale, comma scale, false California apple scale). Scale insects are so named because they cover their bodies with a waxy shield. Under reliable protection, they feel great, sucking juices from plants. These insect pests multiply very quickly and within a few hours after the larvae hatch, they cover the entire tree. Berry plants are also harmed by raspberry beetles, nematodes, glass bugs, Californian scale insects, and raspberry gall midges.

Fighting methods

There are quite a few ways to protect gardens, vegetable plots and fields, as well as forests and parks. Annual pest control is no less important than soil fertility and moisture. There are both specific methods aimed at exterminating one type of insect, as well as general ones. Methods are divided into:

• Agrotechnical - these include cleaning fields and gardens after harvesting. By depriving insects of a place to winter, their mass reproduction can be prevented. Breeders are constantly creating new pest-resistant varieties. It is necessary to plant the plants correctly. Maintain the required distance. Alternate various types, observe crop rotation. This will reduce the damage that insect pests cause to the garden.
• Biological methods involve the colonization of agricultural areas with insect enemies. These can be birds and rodents, insect predators, as well as actinomycetes, bacteria and viruses. Insect pests are eaten by their natural enemies or die from diseases that are harmless to humans and plants. Biological control agents also include pheromone traps.
• Mechanical methods involve manual collection of larvae and insects, as well as complete removal of infected parts of the plant.
• Physical methods involve treating the affected material at high or low temperatures, electric shock. Mainly used against barn pests.
• Chemical - widely used in agriculture, involve treatment with pesticides and other poisons. No substance is completely selective and is harmful to humans and other organisms. To combat chemical methods, complex technical means- airplanes, various sprayers, fumigation chambers. Chemical methods controversial, but they are the cheapest and most effective. After treatment, plant pests will not be able to cause significant damage to your crop. To prevent pesticides from getting into agricultural products, pesticides are used for preventive purposes, before fruiting begins.

The wisdom of nature has created mechanisms for regulating the number of species. Thus, the ladybug feeds on aphids, and birds destroy caterpillars and scale insects on trees. Natural enemies of our enemies will help reduce the number of uninvited guests in the garden. Do not rush to use broad-spectrum chemicals. Not all insects are plant pests; some can be beneficial.

animals damaging forest trees and shrubs. The vast majority of V. l. belongs to the class of insects; some types of ticks and vertebrates, especially rodents (Mouse-like rodents) and lagomorphs (Hares), are less harmful. Depending on the nature of nutrition of V. l. are divided into needle- and leaf-boring (primary) ones that attack healthy plants; stem (secondary), attacking weakened trees; root, or soil-dwelling; pests of fruits and seeds.

Stem V. l. very numerous, belong to the orders of beetles (mainly bark beetles, longhorned beetles, golden beetles, weevils), hymenoptera (horntails) and butterflies (carpenter beetles, glass beetles). As a rule, they lead a hidden lifestyle; only adult insects live openly (in bark beetles, they spend most of their lives inside tissues). By gnawing holes in phloem, cambium and wood, they often cause trees to dry out; many make deep passages in the trunks, depreciating the value of the wood. Mass reproduction depends on the viability of trees, plantings and their sanitary condition. Stem pests usually inhabit weakened trees. In plantations with poor sanitary conditions or located near areas of mass reproduction of secondary pests, even completely healthy trees are often colonized by them. Control measures are predominantly preventive: forestry measures that increase the biological stability of plantations (creation of mixed crops with undergrowth, selection of species in accordance with local climatic and soil conditions, resistant to diseases and pests, correct choice of felling system, compliance with sanitary rules, etc.) , timely cleaning of felling sites from logging residues, etc. It is effective to lay out trap trees in plantations, for which they use diseased and severely weakened trees fallen by wind, storm, snow, which attract pests that fly in the spring (a month before the start of summer) and in the summer (immediately before the start of summer or when the first beetles appear). After infestation by pests, trap trees are debarked during the period while the insects are developing under the bark and they have not penetrated either into the wood or into the thickness of the bark, and the bark is burned or scattered in open areas with the bast facing up. Medicinal chemical means of control are beginning to become widespread.

To the root V. l. include the larvae of beetles and other lamellar beetles, click beetles (wireworms), darkling beetles (false wireworms), as well as some other species that live and lay eggs in the soil, where all their development takes place. Preventive and exterminatory control measures are used against these pests, which pose a great threat to nurseries, forest crops and field protective plantings. Preventive measures include forestry and silvicultural measures, exterminators include chemical ones (mixing seeds before sowing with insecticides, introducing insecticides into the soil and treating seedlings, saplings and cuttings with them, aerial pollination of plantings against adult beetles, etc.) and some physical and mechanical control measures. In relation to specific cases, systems of measures are developed based on data from special surveys.

Pests of fruits and seeds, which include a large number of insect species from different families and orders, damage the generative organs of tree species and often cause great damage to forestry. The fight against these pests is difficult, since most of the time they lead a hidden lifestyle inside seeds and fruits. See also Pests of agricultural plants.

Lit.: Forest entomology, 4th ed., M. - L., 1961; Vorontsov A.I., Biological principles of forest protection, M., 1963; Supervision, accounting and forecast of mass reproductions of needle- and leaf-eating insects in the forests of the USSR, ed. A. I. Ilyinsky and I. V. Tropin, M., 1965; Khramtsov N.N., Padiy N.N., Forest stem pests and their control, M., 1965; Rudnev D.F., Chemical means of controlling forest pests, M., 1966.

N. N. Khramtsov.

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• - rodents and insects that cause damage to transported goods. Among the rodents that live in cargo warehouses in ports and on ships, the most common is the gray rat, as well as the house mouse and water rat...

  Dictionary of business terms

• - animals that damage cultivated plants or causing their death...

  Dictionary of business terms

• - a group of pests of grain and its processed products...
• - barn pests, animals that damage and destroy grain and grain products during storage and transportation...

  Great Soviet Encyclopedia

• - enemies of bees, various animals that feed on bees or their waste products and cause harm to beekeeping...

  Great Soviet Encyclopedia

• - animals that cause any harm to humans directly or indirectly, causing damage to animal husbandry, crop production, forestry, etc. Directly harming humans are their external and...

  Great Soviet Encyclopedia

• - the “harmful” ones are alive, the “harmful” ones are alive...

  Russian spelling dictionary

"Forest Pests" in books

VOICES OF THE FOREST