Herbivorous mites are very small, difficult to notice and barely visible to the naked eye, and some individuals are difficult to see even under a magnifying glass. The species identity of these ticks is almost impossible to determine in the field. Great importance to understand who is harming and how to fight, the nature of the damage caused by ticks.
First, a short excursion into the taxonomy of these pests, which are not essentially insects, and therefore it is not effective to fight them with conventional drugs.
Ticks belong to the class Arachnida. Mostly, ornamental plants are damaged by representatives of two orders of mites (although the taxonomy of these taxa is constantly changing).
Acariformes mites– among them, the greatest damage to plants is caused by mites from the superfamily Tetranychoidea mites. These include spider mites (Tetranychidae) and flat mites (Tenuipalpidae). Very peculiar mites from the order Trombidiformes superfamilies of quadrupeds, or gall mites (Eriophyidae).
Spider mites (Tetranychidae)
Small: length of females - 0.4-0.6 mm, males - from 0.3 to 0.45 mm. Fertilized eggs produce females, and unfertilized eggs produce males. Ticks feed by sucking juices from leaves and young shoots. The upper side of the affected leaves is covered with yellowish spots and dots, and if you examine the leaves in the light, you can see pinholes on the underside.
A characteristic sign of the presence of this mite is the appearance of a thin white cobweb along the edge of the underside of the leaf, and coniferous plants- between the needles. A sign of tick infestation is also the presence of back side leaves of grayish molt skins, similar to dandruff. Ticks overwinter in the bark of shoots and branches of garden plants, in the crevices of greenhouses, in fallen leaves, and in weeds.
Common spider mite (Tetranychus urticae)
A ubiquitous species. Particularly dangerous for young plants. The body is 0.2-0.5 mm long, greenish-yellow, with dark spots on the sides, and has four pairs of legs. Wintering females are orange-red. The larvae are smaller and have three pairs of legs. The eggs are round, translucent, greenish in color. Both adult mites and larvae that settle on the underside of leaves cause damage. Damaged leaves first become covered with light dots, then become marbled, covered with cobwebs, turn yellow and fall off. The development of mites is promoted heat and dry air. At a temperature of 29-32 °C, development lasts 8-10 days. During the warm season, the spider mite produces 8-12 generations. At high air humidity, the reproduction rate decreases.
Boxwood mite
(Eurytetranychus buxi) Damages boxwood. The female is small, up to 0.45 mm, greenish-brown in color. The eggs are round, orange-yellow, 0.12-0.16 mm in size. The larva is light yellow, immediately after birth with three pairs of legs, about 0.2 mm; nymphs are green, with four pairs of legs, 0.3-0.4 mm. Eggs laid on the underside of leaves overwinter in groups. The hatching of the larvae coincides with the beginning of boxwood buds. Development is happening quickly, in southern regions, for example in Crimea, can produce 9-10 generations per year. The female lives about 30 days and lays up to 50 eggs.
Spruce spider mite (Oligonychus ununguis)
It causes great harm to spruce trees, especially Canadian spruce and its form ‘Konika’, as well as thuja occidentalis, juniper, and biota.
Symptoms of damage are a thin, sparse web entangling the needles, in which females lay eggs. In places where the female and mite larvae suck, the needles become covered with yellowish spots, and later become brownish in color and fall off. The tick is oval, reaches a size of 0.4 mm, grayish-green, with four pairs of legs. The larva develops in 10-20 days. Over the summer, the female gives 3-5 generations. Eggs overwinter on last year's shoots. The greatest damage occurs at the end of summer, especially in hot, dry years, to trees with poor watering.
Control measures: Actellik drugs. Agravertine, Fitoverm, Neoron. Good hormonal drugs are Apollo and Flumite. These drugs not only kill feeding individuals, but also affect the viability of eggs.
Flat mites (Tenuipalpidae)
They are sometimes called false spider mites because they are closely related. Very small - from 0.1 to 0.4 mm. Under a microscope, the difference between these families is visible: spider mites have a solid body, while flat mites have a body divided by transverse sutures into several parts (front, middle and back). The body shape and color of the eggs are also different, which is often reddish-brown. High air humidity does not affect the rate of development of flat beetles, while it delays the development of spider mites. They feed, like spider mites, mainly on the underside of leaves. In many flat beetles, the saliva is toxic, and therefore, when feeding, necrosis of leaf tissue occurs, which manifests itself in the appearance of brown or gray-brown spots. Flat beetles are also dangerous because they are the main carriers of mosaic and ring spot viruses.
Typical representatives of flat mites are fruit flat beetle, greenhouse flat beetle, yew and others.
Yew beetle (Pentamerismus taxi)
Found wherever yew grows. Damages the bark of one- and two-year-old shoots and yew needles. Damaged needles turn yellow and fall off prematurely. The bark of the shoots in the areas where the mites are sucking dies and cracks. The female is 0.3 mm long, orange-red. The egg is orange-red, 0.1 mm long. The larva is bright red, with three pairs of legs, 0.15 mm long. Females overwinter in cracks and folds of the bark and under the bud scales. Females begin laying eggs in depressions in the bark of shoots in late March - early April and live, continuing to lay eggs until July. Development from egg to adult female lasts 50-57 days. Develops in 1-2 generations per year.
Control measures: treatment of yew with acaricidal preparations is carried out in the spring, before overwintered females begin laying eggs.
Fruit beetle (Cenopalpus pulcher)
Damages a large number of fruit plants. Prefers to settle on plants with pubescent lower surfaces of leaves. The female is 0.34 mm long, the male is 0.26 mm long; the body is elongated, brick-red in color. The eggs are red, about 0.11 mm, the larva is red. Fertilized females overwinter in cracks in the bark and behind the scales of the buds. The beginning of the mass emergence of ticks in the spring from wintering places coincides with the phenophase of the pink bud of the apple tree and lasts 5-8 days. With the appearance of young leaves, mites move to their underside and
begin to feed and lay eggs. The average fertility of females is about 20 eggs. During the year it develops in 1-2 generations. The duration of development from egg to adult tick lasts from 40 to 50 days.
Control measures: early spring spraying with acaricidal preparations.
Four-legged ticks (Eriophyoidea)
One of the largest groups of plant pests, including more than 4,000 species. These are very small mites - 0.1-0.3 mm, but they pose a serious threat to plants, not only sucking juices, but also causing changes in the shape of cells and organs. Thus, when feeding on a plant, the mite, when piercing the membrane of living cells, secretes saliva, which contains a substance that has a teratogenic effect in many species. As a result, various pathological new growths of galls can develop on the plant: felts, plaques, curls, horns. In addition, with the saliva of mites, phytopathogenic bacteria and viruses penetrate into plant cells - the causative agents of such serious diseases as peach mosaic, currant reversion, wheat stripe mosaic and many others.
Currently, there are five main types of galls caused by four-legged mites: leaf, stem, bark, bud and fruit. For example, various formations appear on the leaves: felts, plaques, curls, horns, vein galls. These formations significantly weaken the plant and reduce their decorative value. The appearance of the galls may indicate which pest caused the disease.
It is difficult to combat gall mites, since acaricidal drugs do not have a pronounced systemic effect.
Types of mites that form galls and felts
Hawthorn edge mite (Eriophyes goniothorax)
It develops on common hawthorn, causing the leaf edge to curl onto the upper side. The inner surface of the gall is covered with whitish thick felt. The galls darken over time.
Pear gall mite (Eriophyes pyri)
It affects the leaves of pear, quince, hawthorn, rowan, and cotoneaster. Forms galls in the form of low flattened swellings. The galls are first green, then Brown. If the mite settles on young fruits, the fruits become distorted and fall off.
Willow three-rayed gall mite (Eriophyes triradiatus)
Causes peculiar formations called “witches’ brooms”.
Grape felt mite, grape itch (Eriophyes vitis)
A common pest of grapes. It affects leaves, less often young shoots, brushes, and buds.
Yew bud mite (Cecidophyopsis psilaspis)
Settles in both vegetative and reproductive buds. Number
increases from May to August, maximum in June, minimum in March and October. The size of the mites is very small, there are up to 100 mites in a bud.
Linden gall mite (Eriophyes tiliae)
Forms characteristic, highly elongated galls on the upper side of the leaf blade.
Alder felt mite (Eriophyes brevitarsus)
Affects alder leaves. Damaged leaves quickly lose their decorative properties and fall off early.
Nut felt mite (Eriophyes erineus)
Affects leaves walnut. The galls look like large round swellings. On the underside, the leaves are covered with a very thick yellowish felt.
Walnut gall mite (Aceria tristriata)
Methods for controlling ticks
There is a fairly extensive list of drugs available to combat ticks. The most common, of course, is Aktellik. But since today there are no approved systemic acaricides, the fight against ticks, especially latent ones, is difficult.
The solution to the problem is somewhat facilitated by the use of drugs with translaminar properties, that is, with the ability to penetrate plant tissue to a certain depth, but not spread throughout the vascular system. Has a good translaminar effect Abamectin, which has a neurotoxic effect on many ticks and thrips. A new class of drugs, lipid metabolism inhibitors LBI, have shown good effectiveness against ticks. These are drugs Envidor, Oberon and Judo. These preparations can also be used to treat indoor plants.
As already mentioned, ticks are not insects, and treating them with conventional preparations designed to kill insects - insecticides - will not have an effect.
Spider mites - how to fight?
One of the worst enemies of plants is the spider mite. How to deal with it?
Description
Spider mites damage more than 200 species of plants, including fruit, vegetable and ornamental plants. In the southern zone (sometimes in the middle zone) it harms open ground, everywhere - in protected ground.
These are small mites (up to 0.45 mm) with a rounded body, covered with sparse, but quite noticeable under magnification, bristles, with four pairs of legs. All species weave a barely noticeable web around the affected areas of the plant, which is why they got their name.
Life cycle
In spring, the mite awakens at a temperature of 12-13°C and first develops on weeds, from which it penetrates onto cultivated plants. The development and reproduction of mites depend on temperature and humidity. Optimal temperature for tick development – 29-31°C. Under such conditions, development from egg to adult phase ends in 7.5-9 days.
The optimal humidity for pest development is 35-55%. High humidity (above 80%) suppresses the development and reproduction of spider mites.
Intensive settlement
Plant mite infestation occurs in July–August. At high summer temperatures, some females stop feeding and migrate in search of shelter until the end of the extremely hot season. All this makes it very difficult to fight spider mites.
During the growing season, the spider mite produces 12-15 generations or even more. Adult females live up to 40 days and lay up to 10Q-160 eggs, placing them on the leaves, on which further development of the mite occurs.
Pest on plants
Spider mites feed on the contents of plant cells. Some cells are destroyed, the area and intensity of photosynthesis decreases, the plant weakens and becomes more susceptible to any infections.
MEASURES TO COMBAT SPIDER MITES
Agrotechnical
The main agrotechnical measures to combat spider mites are compliance with crop rotation and the use of a set of agricultural techniques (burning post-harvest residues, deep fall plowing, weed control, fertilizer, watering, etc.) aimed at growing strong plants that are more resistant to mite damage.
Chemical
A tick is not an insect, and insecticides have no effect on this class of pests. In the fight against ticks, acaricides or insectoacaricides must be used. Unfortunately, there are practically no systemic acaricides that are safe for humans. It is necessary to use drugs with enteric contact action. Therefore, it is important to carry out the treatment very carefully and at certain intervals.
Spider mites carry a range of infections - gray mold spores and viral infections of agricultural and ornamental crops. Therefore, it is so important to start fighting it in a timely manner.
The most harmless drugs are the avermectin group Aktofit, Fitoverm, Vermitek. But they do not affect eggs and non-feeding female mites, so a single treatment will not lead to anything other than a temporary reduction in the number of the pest. These drugs do not act at temperatures below 18°C and are not stored in solutions for more than a day.
At a temperature of 20°C, at least 3 treatments are required with an interval of 9-10 days. At 30°C – 3-4 treatments with an interval of 3-4 days. Otherwise, the female that emerges from the egg has time to mature (6-7 days at 30°C) and lay new eggs.
Biological
In protected ground, it is advisable to release predatory mites - phyto-seiulus. They are much more effective than any chemicals if the room is high humidity, warm and no chemical treatments are carried out. If the pest outbreaks are single, then leaves with phytoseiulus are laid out at the rate of 15-60 individuals per plant with a predator-to-prey ratio of 1:80 (in greenhouses under film) to 1:20 (in large-block greenhouses).
In greenhouses with neglected foci, a mass release of phytoseillus is used evenly throughout the entire cultivation room at the rate of 50-100 predatory individuals per 1 m2 of greenhouse area.
Treatments with the following biological products are also effective:
Bitoxibacillin, P (multiple spraying with 0.7-1% working solution with an interval of 15-17 days);
Fitoverm, CE (twice spraying with working solution (0.1%) with an interval of 20 days, waiting period 2 days).
Please explain whether insecticides work on ticks? What kind of drugs can be used to kill them?
Mikhail Filimonovich KUDARENKOV, Smolensk region, Safonovo
Ticks, like spiders and scorpions, are not insects. They have a different biology, so conventional insecticides do not work on them. Special drugs are used against these creatures - acaricides or insectoacaricides (they work against ticks and insects). Let's look at the most effective of them.
This drug is specially created to combat arachnids. This acaricide is available in the form of a wettable powder and emulsion. In the first case, it is packaged in bags, in the second - in ampoules and bottles. The concentration can also be different: 300 g/l (30%) - Omite 30 and 570 g/l (57%) - Omite 57. The active substance is propargite, which penetrates the tick's body by contact. The effect occurs almost instantly: after treatment, the ticks die within a matter of minutes. Along the way, the drug destroys some insects, for example, thrips. The protective period lasts up to two weeks.
« Omite» used at an air temperature of at least 25 degrees and no wind. The working solution is prepared strictly according to the instructions and used immediately; it cannot be stored for longer than two hours. Plant treatments are stopped 3 weeks before harvesting fruits and vegetables.
"Neoron"
Treatment should be planned so that at the time of application of the acaricide and 3-4 hours after that there is no wind, precipitation, high humidity and strong solar activity. Depending on the number of pests, use 10 to 20 ml of the product dissolved in a bucket of water. This amount is enough to process 10 bushes, 2-5 trees or one hundred square meters of plantings. Storage of the solution is allowed for no longer than 2 hours.
"Antiklesch" and "Fufanon"
Both of these drugs are insectoacaricides, that is, they act on both insects and arachnids. They contain the same active ingredient malathion in the same concentration. Available in the form of an emulsion concentrate, packaged in 10 ml bottles and 5 ml ampoules.
Malathion penetrates the body of ticks by contact, as well as through food orally - into gastrointestinal tract. It has very high physiological toxicity, especially for ticks and insects. In greenhouses and greenhouses, malathion lasts up to 7 days, in open ground - up to 10 days.
Against ticks use 10 ml of the product dissolved in 10 l cold water. To treat 1 tree or bush, you need from 2 to 5 liters of solution. For processing 10 sq. m of planting requires 1 liter. To achieve maximum effect, plants should be moistened evenly with the solution, avoiding dripping onto the ground.
« Fitoverm»
This insectoacaricide belongs to biological preparations. It is based on a complex of streptomycete fungi (aversectin C), which has a detrimental effect on ticks and many insects. Penetrating into the body of pests by contact or through the digestive system, the drug affects nervous system, causing convulsions, then paralysis and death of the ticks. Their appetite disappears after 7-9 hours, and death occurs on the 3-5th day. Protection lasts no more than 20 days.
On a note
The effectiveness of Fitoverm against plant mites is 96-100%, which has been confirmed by research and experiments. In this case, the harmful effect of the drug increases with increasing air temperature.
Available in the form of an emulsion concentrate, packaged in ampoules with a capacity of 2, 4.10 ml and 5-liter canisters.
It is used in the absence of wind and any precipitation, as well as in reduced solar activity (in the evening or in cloudy weather). The rule applies: the higher the air temperature, the more effective the drug is. Humidity reduces the effectiveness of the product.
To kill ticks, 1 ml of the product is diluted in 1 liter of water, and then diluted to a volume of 10 liters. This amount is enough to process one hundred square meters of plantings. The working solution cannot be stored.
On a note
In cases where there are a lot of pests, Fitoverm is not effective enough due to its distinctive feature - delayed action on mites and insects. After all, before they die, they still have time to cause significant damage to the plantings. In this case, it is better to use acaricides with almost instantaneous action. And for proactive impact, when the concentration of pests is low, Fitoverm is well suited. Its use is especially useful during fruit ripening. The complete disintegration period of the drug is 30 hours in the ground and three days on the surface of leaves and fruits of plants.
Agronomist Dmitry Petrovich MEZIN, Bryansk, answered readers’ questions
: Calendar of necessary work in the garden...: How to deal with diseases and...
From time immemorial, linden has been an ideal tree for landscaping. If trees grow in a bunch, they may be attacked by harmful insects. In addition, signs of certain diseases often appear on linden leaves. In this article I will tell you which linden diseases are the most common.
Most often, young linden trees, as well as trees growing along highways and roads, are susceptible to the development of diseases. The most common infection that develops on linden leaves is a fungal infection.
Spots on leaves
The development of the disease is indicated by the appearance of numerous white spots with a dark border on the surface of the leaves. Affected leaves wither, turn yellow and fall off. This process is observed regardless of the time of year - leaf fall as a result of the development of the disease is possible even in mid-spring or summer.
Prevention and treatment:
- affected leaves are removed from the tree and burned;
- disinfection is carried out by spraying the tree with Bordeaux mixture.
Thyrostromosis
An infectious disease caused by the activity of a pathogenic fungus can often be observed on young trees.
Signs of damage are dark spots that form on the shoots, leaves and trunk of the tree. During development, the areas affected by dark spots die off. Subsequently, necrosis spreads throughout the entire structure of the linden tree.
Prevention and treatment:
- affected branches and leaves are removed and burned;
- You can destroy infected branches by trimming the crown;
- treatment of linden with disinfectants (Fitosporin) is carried out in early spring;
- Prevention of the disease is treatment in spring and autumn with a solution of copper sulfate;
- Regular weeding and loosening of the soil will help prevent the development of pathogenic fungi in the soil.
White marble rot
- trunk curvature;
- cracks on the surface of the trunk;
- unhealed branches.
Prevention and treatment:
- Regular feeding of linden will help prevent the development of the disease;
- Prevention of infection of healthy plants and trees will be the treatment of cracks and broken branches with disinfectant compounds, for example, a mixture of crushed chalk in a solution of potassium permanganate.
Seedlings are lodging
A disease characteristic of young linden seedlings. We can talk about the development of a pathological process if the seedlings begin to wither, their leaves turn yellow, and the trunk softens. Afterwards, the seedlings begin to bend lower and lower towards the ground, after which they die.
The cause of the disease is a fungus that infects root system young linden tree.
Treatment and prevention:
- linden seedlings must be planted at the end of spring;
- Prevention of infection of healthy seedlings is disinfection of the soil with special compounds.
Linden pests
Willow scale
By external characteristics adult insects can be mistaken for plaque on the surface of leaves. The willow scale insect is a small, sucking insect that is off-white or gray in color. The shape of the pest resembles a pear.
Numerous colonies of scale insects can destroy a tree. Signs of damage are:
- leaf dying;
- fruit drop;
- development of rot and blackness on the trunks and root system of linden.
Gall mite
Formation of pests:
- at the end of summer - beginning of autumn, greenish galls form on linden leaves, which subsequently turn red;
- a whole “army” of mites is formed inside the cone-galls;
- mites move into the kidneys, sucking out all the juices from them;
- the result of the pest is the death or deformation of shoots growing from the affected buds.
Butterfly Moth
Nondescript on appearance butterflies lay eggs on the trunk of a linden tree in early spring. As soon as the caterpillars hatch from the eggs, oppression of the tree begins. The voracious caterpillars gnaw almost all the soft structures of the linden tree - leaves, buds, flowers.
Butterfly Luna silver
Butterfly Goldentail
The caterpillars hatch in the summer. In autumn, the insect does not pose a threat to tree leaves, since they are a reliable place for wintering. But at the beginning of spring, hungry caterpillars feed on linden leaves, buds and flowers.
Silkworm Butterfly
A very beautiful butterfly can cause significant harm to a linden tree. The silkworm lays eggs in the lower part of the tree trunk, the hatched caterpillars begin to actively feed on fresh leaves, gnawing and destroying them completely.
Butterfly Leafroller
The activity of the voracious leaf roller caterpillars begins in April. During the spring and summer, the caterpillars gnaw on the succulent leaves of the tree.
Butterfly Dipper
The voracious caterpillars of the butterfly devour both the leaves and the bark of the linden tree.
Signs of damage:
- a thin white cobweb appears on the surface of the leaves;
- Leaf absorption starts from the bottom.
Pest Control Methods
An effective method of combating harmful insects is spraying linden with insecticidal solutions. Spraying should be done carefully. Trees should not be processed in windy or rainy weather.
Another method of pest control is gaining popularity: injections. Pricks (injections) for trees are reliable protection against attacks by harmful insects and the development of pathological processes. In addition, this technique contributes to the formation of tree resistance to negative external natural factors.
Let's sum it up
- Young linden trees are more likely than adults to develop fungal infections.
- Disinfecting compounds are used to treat affected linden trees.
- Insect pests pose a danger to linden leaves. Numerous colonies of insects can destroy a tree.
- Insecticidal spraying is an effective method of pest control.
Linden is a genus of woody plants that includes about fifty species of trees and large shrubs.
IN Lately linden is often affected by gall mites, resulting in damage to the leaves - galls. Because of this, the leaves dry out and fall off, and the plant itself becomes more susceptible to disease. As a result of such damage, the tree begins to lose its medicinal properties.
Other plants, such as oak, maple, birch, willow, bird cherry and others can also be damaged by galls.
Characteristics and harm of the linden gall mite
Gall mites are four-legged insects of the superfamily of arachnids, the order of acariform mites. Gall mites are very small - their size does not exceed 0.1-0.6 mm. They do not have organs of vision or breathing, they feed on the contents of the cell, causing the destruction of plant tissues and various deformations and deformities of leaves and shoots.
Gall mites can become sources of infection.
Methods of combating linden gall mites
If plants with characteristic damage are detected, it is necessary to take timely measures to combat pests and, as a result, preserve the plants.
It must be remembered that the fight against gall mites should begin not from the moment the galls appear, but during the period when the mites emerge from them (from late June to mid-July).
To combat the gall mite, linden trees use several methods.
First and the most popular is treatment with insecticides and acaricides at the beginning of bud break. Not the safest method, but quite effective. In this case, the main thing is to choose the right drug for a specific pest, otherwise you can get the opposite effect. To consolidate the result, the treatment should be repeated after the expiration of the drug.
The injected drug enters all parts of the plant, and is thereby capable of destroying the mite at the larval stage, since it penetrates directly into the pest’s body along with nutrients. This procedure will help the infected linden tree to recover and cope with the mite. In an advanced situation, injections can be carried out at any time of the year to preserve the plant.
Prevention
Of course, the most effective way destroying a tick is prevention. In order to prevent the development of gall mites, the linden tree must be treated chemicals, better in early spring when the buds begin to appear.
When working with pesticides, it is imperative to take care of the person’s personal protective equipment - perform the work with gloves, a respirator and goggles, as well as thick clothing. It is unacceptable for the substance to come into contact with open areas skin.
To avoid further infection of garden plants, it is better to burn the fallen leaves of a diseased linden tree. It is also important proper care, which consists of timely fertilization, pruning and processing.
If you adhere to all preventive measures and do not let the situation get worse, then the problem of gall mites in linden will not become a big problem for the gardener.
Sometimes peculiar growths can be observed on the leaves or stems of many plants, including oak, maple, bird cherry, birch and others. They can be red, white, green, spherical or oblong, shiny or dull.
This issue is often discussed on numerous forums - such an original, sometimes even cute, manifestation of the disease. What is behind these growths? The growths on the leaves are called Gauls. So, galls are formations on leaves, stems, and buds of plants, provoked by insect bites - gall mites. As a rule, galls themselves are harmless, but they indicate a rather serious problem with the plant. Normally, galls should not be visible on the plant at all. If growths are found on a large part of the plant crown, then this is abnormal and must be dealt with.
Education mechanism
The mechanism of gall formation is similar to the development of an inflammatory response in the human body. When injured, the immune system promotes increased formation of additional tissue at the site of injury. The same thing happens with plants. By forming galls, plants try to protect the site of injury (insect bite). The formation of galls is also facilitated by the pests themselves, secreting saliva and thereby increasingly irritating the plant tissue. 
Galls can appear not only on leaves, stems, but also on buds, roots or flowers. They can be almost invisible or grow to enormous sizes, causing real deformation of the tree. Among all types of galls, the greatest danger to a tree is caused by crown galls in the form of a brown, warty growth on the trunk or roots, which is caused by bacteria. If the crown gall wraps circularly around the trunk, the consequences for the tree can be disastrous.
A more common variety is galls that appear on leaves and are caused by gall mites. Gall mites are four-legged insects of the superfamily of arachnids, the order of acariform mites. Gall mites are very small - their size does not exceed 0.1-0.6 mm. They do not have organs of vision or breathing, they feed on the contents of the cell, causing the destruction of plant tissues and various deformations and deformities of leaves and shoots. Sometimes most of the activity occurs inside the galls. life cycle insect.
For example, a female gallworm insect pierces a leaf bud of an oak tree and lays a larva there. A ring-shaped growth begins to develop around the larva. After only 5-6 months, the developed larva turns into a gall worm, gnaws through the gall that shelters it and climbs out.
Variants of manifestations
Interestingly, people have long used oak galls to produce ink. Even in the old days they were called “ink nuts.” These same ink nuts found their application in Skornyakovsky and pharmaceutical business. They were widely used for tanning leather, and astringent medicines were also made from them.
There is another interesting phenomenon in nature, also associated with the formation of galls - this is inquilinism. An inquiline animal enters the home of another animal with the goal of destroying it. In the case of galls, such inquiline animals are often ichneumon wasps, which lay their larvae in the galls. The wasp larvae gradually suck out the gall larva, then begin to eat the walls of the gall.
Fighting methods
Galls spoil the appearance of an ornamental plant and reduce the crown area involved in the process of photosynthesis. Gall mites can become sources of infection. The fight against gall mites consists mainly of preventive treatment. If growths on the leaves have already appeared, then the fight becomes more difficult. Already damaged leaf plate cannot be restored. In this case, treatments are carried out with systemic acaricides and pyrethroid insecticides. A properly selected acaricide will stop the development of the pest population. And, conversely, incorrectly selected drugs can even spur the activity of the tick, making further fight difficult. Insects have a unique ability to adapt to any poison. In gall mites, this adaptation occurs very quickly. Therefore, it is important to select an insecticide that is effective on a specific type of pest in order to destroy the entire population at once (or in several treatments, depending on the time of treatment, the degree of infection and the selected drugs).
Contact us and get professional advice from a forest pathologist on how to combat gall mites and other pests in your garden. If you prefer not to carry out the recommended activities yourself, we will carry out all the necessary work efficiently and in a timely manner. In our work we use the best modern drugs that are safe for humans and animals.
A survey of linden trees in the Central Administrative District of Moscow (Alexandrovsky Garden metro station) showed severe damage to the leaves by the linden felt mite. Processing needs to begin immediately.
Linden felt mite Eriophyes leiosoma Nal. belongs to the family of plant mites – Eriophyidae. The length of this mite is 0.12 – 0.20 mm. The female mite lays eggs on the underside of the leaf, where yellowish-white spots (felt galls) appear.
Felts can be either on the bottom or on top of the sheet.
Yellowish spots form on the upper side of the leaf. Females overwinter in the buds of the plant.
Measures to protect against the linden felt mite.
To combat the pest during bud break, acaricides (preparations against plant mites) are used; they are used a second time after flowering. Autumn treatment is aimed at destroying ticks during wintering. A good result can be obtained by spraying with infusions of garlic, onion and celandine.
Preparations against plant mites:
Omite, apolo, fitoverm, flumite, BI 58, clipper, demitan.
Information provided by:
Head of the plant protection department of the Agro-Industrial Complex “Vitus” Konstantin Yurievich Sinelnikov
Specialists of the plant protection department of AIC "Vitus" carry out entomological and phytopathological examination of green spaces, develop individual action plans for plant protection, treat green spaces with protective agents and provide comprehensive plant care.
Plant Protection Department of AIC "Vitus": [email protected]
