Foke gall mite on sugar maple leaves. Forest secrets (Petrov V.V.) Galls on leaves how to fight

By autumn, yellowish or yellow-pink balls - galls - the size of a small cherry, often develop on oak leaves. They look like tiny apples of the correct spherical shape.

Galls are painful growths of leaf tissue. The gall midge insect, which looks like a very small fly, is to blame for their appearance. The gall midge pierces the skin of the leaf with a thin, sharp ovipositor and lays an egg there. Some time after that, a "ball" grows on the sheet. If you break such a ball in late autumn, in the middle of it you can find a small white worm - a gall midge larva- or already an adult insect. In some years, oak leaves are literally dotted with galls - there are several of them on each leaf.

Gauls are sometimes called ink nuts. This name is not accidental. Our ancestors at the time of Pushkin used them to make black ink. How to get ink in this way? It is necessary to prepare a decoction of nuts and add a solution of iron sulfate to it. Merging two weakly colored liquids, we get a completely black liquid. This chemical "focus" is easily explained. The gall contains many tannins, and they have the ability, when combined with iron salts, to give a thick black color. The same can be done with tea infusion (it also contains a lot of tannins). If a few drops of a yellowish solution of ferric chloride are added to a glass of weak tea, the liquid becomes completely black.

oak pests

Leaf-eating and stem pests, and fungal diseases are the most important factors that increase the drying of oak stands. Violation of the ecological balance of oak forest phytocenoses, especially in oak forest monocultures, leads to violations of the water regime of the territories, changes in light and temperature conditions in the plantation, and all together - to the formation of conditions more favorable for the development of pests and diseases.

Oak is damaged by a huge number of pests and diseases. Different authors give different figures on the number of pests and diseases that damage the oak. In the Tellerman forest, 184 species of foliage pests were identified (Molchanov, 1975). Among the most common pests that damage foliage, we should name: 5 types of silkworms, 5 types of cutworms, 6 types of moths, 8 types of moths, 8 types of sawflies, 2 types of leafworms, 11 types of gall wasps, 2 types of psyllids, 5 types of weevils, 2 types of Hermes, 2 species of aphids and 3 species of plant mites. Buds and flowers damage 12 species of gall wasps. Acorns are damaged by 2 types of codling moths, 3 types of weevils and 1 type of nutworm. The trunk and branches damage 8 species of bark beetles, 7 species of longhorn beetles, 3 species of horntails, 2 species of woodworms, 1 species of flat-footed beetle, 3 species of borers, 1 species from the family of whetstones, 1 species of wood borers (Napalkov, 1953).

In Europe, 542 species of harmful insects damaging oak have been identified (Hrast Luznjak…, 1996). A total of 206 species of fungi were found, including zygomycetes - 3 species, mastigomycetes - 2 species, ascomycetes - 50 species, basidiomycetes - 43 species, deuteromycetes - 108 species. 1 virus was found - tobacco mosaic virus (TMV), 14 species of bacteria (Erwinia quercicola Geprges et Bad., Erwinia valachika Geprges et Bad., Pseudomonas quercus Schem, etc.). However, the influence of viruses and bacteria as causes of oak desiccation has not been clearly established (Ragazzi et al., 1995).

The most common oak pests

Not all of these species are mass pests and cause serious damage to oak trees. The most common and dangerous oak pests in the Middle Volga region are:

Primary leaf-eating insects

1) gypsy moth (Ocneria (Lymantria, Porthetria) Dispar L.);

2) goldentail (Euproctis chrysorrhoea L. (Nygmia phaerrhoea L.);

3) ringed silkworm (Malasoma neustria L.);

4) hawthorn leafworm (Cacoecia (Archips, Tortrix) crataegana Hb.);

5) green oak leafworm (Tortrix viridana L.);

6) winter moth (Operophthera brumata L.);

7) peeled moth (Erannis defoliaria Cl.).

Secondary pests of the trunk and branches

1) oak borers (Agrillus angustulis Illig., A. biguttatus F., A. affinis F.);

2) oak sapwood (Scolitus intricatus Ratz.);

3) motley oak barbel (Plagionotus arcuatus L.), yellow-spotted barbel (Mesosa myops Dalm.).

Fungal diseases of oaks

1) powdery mildew (Microsphaera alalphitoides Griff. et Maubl.);

2) common honey agaric (Armillariella melea Guel.);

3) sulfur-yellow tinder fungus (Laetiporus sulphureus Fr.);

4) false oak tinder fungus (Phellinus robustus (Karst.) Bourd. et Galz.);

5) oak sponge (Daedalea quercina Fr.);

6) oak tinder fungus (Inonotus dryophilus (Berk.) Murr.);

7) real tinder fungus (Fomes fomentarius Gill.);

8) cytosporosis (Cytospora intermedia Sacc., C. quercella Sacc.)

9) vascular mycoses (Ceratocystis spp., Ophiostoma spp.);

10) necrosis (Vuilleminia comedens Maire., Nummularia bulliardi Tul., Clithris quercina Rehm, Diatripe spp.).

Primary and secondary pests

Weakened trees are exposed to a complex of secondary stem pests. The symptoms that appear at the stage of oak tree drying out are shown in fig. 16. Three main types of tree drying can be distinguished. The primary factor is necrotic damage to the bark by frost (frost cracking) or by the sun (sunburn and dry flanks), or by humans (bark peeling, type A). These damages can be overgrown, healed by a tree or be a "gateway" for infection. Infecting factors are various types of necrotic (Vuilleminia comedens Maire., etc.), sapwood and wood-destroying fungi, primarily sulfur-yellow (Laetiporus sulphureus Fr.), false oak tinder (Phellinus robustus (Karst.) Bourd. et Galz.) and honey agaric (Armillariella melea Guel.). According to reconnaissance surveys, bark necrosis and sap rot from Vuilleminia comedens (up to 14-25%) are most common in oak forests, heart rot from Phellinus robustus (4-8%) and heartwood sap rot from Laetiporus sulphureus (2- 5%).

Mushrooms and rot

The development of honey agaric, which accelerates the death of oak trees, already occurs on severely weakened trees. The presence of rhizomorphs or fruit bodies in the initial stages of tree damage was not noted, which is confirmed by numerous data (Vakin, 1933, 1954; Vorontsov, 1972; Hartmann et al., 1989; Hartmann and Blank, 1992; etc.). Infestation with honey agaric can reach up to 25% of the total number of examined trees.

Trees damaged by various rots had uncovered frost cracks in 75-80 cases. Many researchers also note that almost all types of the main wood-destroying oak fungi can penetrate through frosty cracks (Vakin, 1954; Matveev-Motin, Alekseev, 1963).

stem insect pests

The second type (type B) is associated with damage caused by stem insects.

Insects have been found to play a very important role in the spread of stem rot.

Through passages made by oak borers (Agrillus angustulis Illig., A. nastalifer. Ratz., A. elongatus Hlbst.) and (or) oak sapwood (Scolitus intricatus) or barbels (genus Mesosa), the infection can either penetrate or more spread rapidly along the trunk. Both barbels and bark beetles are active distributors of spores of vascular mycosis and other fungal diseases. The appearance and development of the fruiting bodies of the sulfur-yellow tinder fungus in the places of penetration of these insects was noted. In these places, sap flow from the trunk is also observed (Matveev-Motin, Alekseev, 1963). A focus of the narrow-bodied oak borer was noted in Tataria in 1944-1947; severe damage by secondary pests was also noted in the Chuvash Republic and the Ulyanovsk region (Napalkov, 1953).

oak infections

The third type is due to the penetration of infection through dead branches in the tree crown (type C). The dying off of branches can be caused both by natural causes and by the influence of frost and intensive eating of foliage by leaf-eating insects and necrotic fungi. In addition, the studies of I.V. Turkevich (1955) showed that the intensive development of water shoots can lead to a lack of moisture in the crown of a tree, as well as cause a more intensive death of individual branches and tops. Often a combination of different types of oak damage can be found on a tree.

powdery mildew

Powdery mildew (Microsphaera alalphitoides Griff. et Maubl.) is one of the main and widespread oak diseases. Most of all, it is dangerous for seedlings and young crops, and it causes noticeable harm to adult plantings only when leaves that have grown back after being eaten by leaf-eating pests are infected (Vlasov, 1951). In this case, with a significant spread of powdery mildew in the crown of the tree, the process of preparing shoots for winter slows down, growth decreases and nutrient reserves in the tree are depleted. Powdery mildew more intensively affects trees growing in open areas and clearings. It has been noted that more intensive development of powdery mildew occurs in the lower part of the crown of middle-aged and mature trees, foliage is more intensively affected on secondary oak growths ("Ivan shoots"), as well as in floodplain conditions (Osipov et al., 1989).

Mycosis

The virulence and significance of vascular mycoses in the death of oak trees in the region have not been studied in detail. According to the expedition survey of oak forests in Chuvashia in 1971 and 1998. (Report on forest pathology survey, M, 1971; Report on forest pathology survey, Bryansk, 1997), vascular mycoses are widespread throughout the region's oak forests, the disease can occur both in acute and in a sluggish form. Under the influence of a number of biotic and abiotic factors, the disease can lead to the mass death of branches and trunks. Therefore, vascular mycosis can be attributed to secondary pathogens leading to the weakening of oak forests, but it is not the cause of the death of oak forests in the region.

Seed propagation in the garden strawberry familiar to us, unfortunately, leads to the appearance of less productive plants and weaker bushes. But another type of these sweet berries - alpine strawberries, can be successfully grown from seeds. Let's learn about the main advantages and disadvantages of this crop, consider the main varieties and features of agricultural technology. The information presented in this article will help you decide whether it is worth giving her a place in the berry.

Often, at the sight of a beautiful flower, we instinctively bend over to smell its fragrance. All fragrant flowers can be divided into two large groups: nocturnal (pollinated by nocturnal butterflies) and diurnal, whose pollinators are mainly bees. Both groups of plants are important for the grower and designer, because we often walk in the garden during the day and relax in our favorite corners with the onset of the evening. We are never put off by the fragrance of our favorite fragrant flowers.

Pumpkin is considered by many gardeners to be the queen of the beds. And not only because of its size, variety of shapes and colors, but also for its excellent taste, useful qualities and a rich harvest. Pumpkin contains a large amount of carotene, iron, various vitamins and minerals. Due to the possibility of long-term storage, this vegetable maintains our health all year round. If you decide to plant a pumpkin on your site, you will be interested to know how to get the largest possible harvest.

Scotch eggs are amazing! Try to cook this dish at home, there is nothing difficult to prepare. Scotch eggs are a hard boiled egg wrapped in minced meat, breaded in flour, egg and breadcrumbs and deep fried. For frying, you need a frying pan with a high rim, and if you have a deep fryer, then it's just great - even less hassle. You will also need deep-frying oil so as not to smoke the kitchen. Choose farm eggs for this recipe.

One of the most amazing large-flowered tub cubanola Dominican fully justifies the status of a tropical miracle. Heat-loving, slow-growing, with huge and in many ways unique bells of flowers, cubanola is a fragrant star with a difficult character. It requires special conditions in the rooms. But for those who are looking for exclusive plants for their interior, the best (and more chocolatey) candidate for the role of indoor giant cannot be found.

Chickpea Curry with Meat is a hearty hot dish for lunch or dinner inspired by Indian cuisine. This curry is quick to prepare, but requires pre-preparation. Chickpeas must first be soaked in plenty of cold water for several hours, preferably overnight, the water can be changed several times. It is also better to leave the meat in the marinade overnight so that it turns out juicy and tender. Then you should boil the chickpeas until tender and then cook the curry according to the recipe.

Rhubarb can not be found in every garden plot. It's a pity. This plant is a storehouse of vitamins and can be widely used in cooking. What is not prepared from rhubarb: soups and cabbage soup, salads, delicious jams, kvass, compotes and juices, candied fruit and marmalade, and even wine. But that's not all! A large green or red rosette of plant leaves, reminiscent of burdock, acts as a beautiful backdrop for annuals. Not surprisingly, rhubarb can also be seen in flower beds.

Today, experiments with non-banal combinations and non-standard colors in the garden are in trend. For example, plants with black inflorescences have become very fashionable. All black flowers are original and specific, and it is important for them to be able to select suitable partners and a position. Therefore, this article will not only introduce you to the range of plants with slate-black inflorescences, but also teach you the intricacies of using such mystical plants in garden design.

3 delicious sandwiches - cucumber sandwich, chicken sandwich, cabbage and meat sandwich - a great idea for a quick snack or for a picnic in nature. Only fresh vegetables, juicy chicken and cream cheese and a little spice. There is no onion in these sandwiches, if you wish, you can add an onion marinated in balsamic vinegar to any of the sandwiches, this will not spoil the taste. Having quickly prepared snacks, it remains to collect a picnic basket and go to the nearest green lawn.

Depending on the variety group, the age of seedlings suitable for planting in open ground is: for early tomatoes - 45-50 days, medium ripening - 55-60 and late terms - at least 70 days. When planting seedlings of tomatoes at a younger age, the period of its adaptation to new conditions is significantly extended. But success in obtaining a high-quality crop of tomatoes also depends on the careful implementation of the basic rules for planting seedlings in open ground.

Unpretentious plants of the "second plan" sansevieria do not seem boring to those who appreciate minimalism. They are better than other indoor decorative foliage stars for collections that require minimal maintenance. The stable decorative effect and extreme endurance of only one type of sansevieria are also combined with compactness and very fast growth - Khan's rosette sansevieria. The squat rosettes of their stiff leaves create striking clusters and patterns.

One of the brightest months of the garden calendar pleasantly surprises with the balance of the distribution of favorable and unsuccessful days for working with plants according to the lunar calendar. In June, gardening and gardening can be done throughout the month, while the unfavorable periods are very short and still allow you to do useful work. There will be their optimal days for sowing with plantings, and for pruning, and for a pond, and even for construction work.

Meat with mushrooms in a pan is an inexpensive hot dish that is suitable for a regular lunch and for a festive menu. Pork will cook quickly, veal and chicken too, so this meat is preferable for the recipe. Mushrooms - fresh champignons, in my opinion, the best choice for homemade stew. Forest gold - mushrooms, boletus and other goodies are best harvested for the winter. Boiled rice or mashed potatoes are ideal as a side dish.

I love ornamental shrubs, especially unpretentious and with an interesting, non-trivial foliage color. I have different Japanese spireas, Thunberg barberries, black elderberry ... And there is one special shrub that I will talk about in this article - the viburnum vesicle. To make my dream of a low maintenance garden come true, it's probably the perfect fit. At the same time, it is able to diversify the picture in the garden very much, moreover, from spring to autumn.

Even in childhood, older people told me about oak (ink) nuts, or galls from which in the past they received ink - hence the name. Then I lived in an area where many oaks grew, but I could not find nuts (or other atypical formations) on any of them.

Later, I learned that oak nuts contain a lot of tannins - natural polyphenols (substances that have several -OH groups connected to the benzene ring). Tannins give a complex with ferric salts, almost black in color - this was the basis for obtaining ink.

Even in ancient Rome, copper sulfate was a commercial product, but even then there were unscrupulous sellers. In particular, copper sulphate was diluted with cheaper iron sulphate. To detect a fake, oak nuts were used: the black color betrayed the presence of iron.

In our time, galls are used to obtain tannin, which is used in medicine.

If I have seen photographs (drawings) of oak nuts before, I do not remember them. For many years I periodically inspected oak sheds and branches in the hope of finding galls, but without success. One day I was walking in the forest. It was autumn and most of the leaves had fallen. On the ground, I found an oak leaf on which strange balls had grown. Most likely, these were oak nuts. I took them with me, found photos of ink nuts on the Internet and compared them - the last doubts disappeared.

Since then, I began to systematically examine the growing and fallen oak leaves; from time to time I found leaves with ink nuts, but at first there were few such finds.

Once I went with two friends to the forest for mushrooms. Friends were also chemists. The three of us managed to find as much as one oil dish mushroom, but already at the beginning of the walk we began to find nuts on oak leaves: both on fallen ones and on those leaves that were on the trees.

It turned out that oak nuts were distributed rather unevenly: on some oaks there were a lot of them, on others it was not possible to find a single one. So picking mushrooms turned into picking oak nuts. Gathered up a big bag. How can one not recall the phrase: "A chemist is a chemist in Africa too."

Later, walking along the shore of Lake Verbne (Kyiv, Obolon), I discovered that there were a lot of oak nuts on the fallen oak leaves that floated in it.

I dried the collected nuts, but I have not yet tried to get tannin from them: I hope that my hands will reach this in the future.

Considering that the prices for tannin in Ukraine are simply draconian (as well as for other medical preparations), the extraction of tannin from oak nuts is not only of "purely sporting" interest.

White coating on oak leaves powdery mildew of oak. It infects the leaves and young shoots of oak almost every year. What to do with it and what other troubles and oak diseases waiting for lovers of this amazing tree?

I have several oak trees of different ages growing in my garden. Alas, almost every year in the middle of summer, the leaves of my oak trees - from annuals to fully mature trees - are covered with a painful white coating. Tired! It's time to deal with this infection once and for all.

Powdery mildew oak

Powdery mildew of oak, which forms a white coating on leaves and green shoots, is a fungal disease. It is generally not dangerous for the tree, but spoils its appearance. In addition, any damage to the leaves, even if they are simply eaten by caterpillars or aphids, weakens the tree. After all, the leaves supply the plant with nutrients produced under the action of sunlight.

Powdery mildew affects not only oak, but also other trees and shrubs. Black currant, for example. The fungus does not affect the lignified parts, but develops only on the green parts.

It is believed that this disease did not become common in Europe until the early 20th century, when the fungus was apparently introduced from the Americas.

How to deal with oak powdery mildew?

With powdery mildew, you can try to fight by spraying the foliage with sulfur-containing preparations or other fungicides powdery mildew. From simple means, a solution of soda or potassium permanganate is recommended. From folk remedies - spraying with fermented milk products, kefir, for example, at the rate of 1 liter per bucket of water. Sour-milk microflora displaces the fungus (as in the human body). They say that a biofungicide also helps with powdery mildew. phytosporin, which also contains a complex of beneficial microorganisms.

This year I spilled a young oak tree with a solution of the EM (“effective microorganisms”) series directly on the leaves from a large watering can. It seems that the manifestation of the disease has decreased. Gotta try this next year. before appearance of powdery mildew.

But once and for all, powdery mildew of oak, apparently, will not be done away with. Spraying a large tree several times a season is tedious to say the least. If you are annoyed by white bloom on the leaves, plant species that are resistant to this infection, for example, red oak(Quercus rubra).

Or galls- spherical formations on the lower surface of the leaf the size of a cherry. Actually, it's not a disease. Small worms live inside the growths - insect larvaegall midges.An adult gall midge pierces a leaf with its ovipositor and lays eggs in it.

The developing larva secretes special substances that provoke active division of leaf cells, resulting in the formation of a cozy (for the larva) apartment - gall. The gall protects the larva from birds and bad weather, and provides food. Inside the gall, it can pupate and overwinter together with a fallen leaf in the forest floor.

The Gauls are called ink nuts because ink was indeed prepared from them back in the 19th century. If iron sulfate is added to a decoction of such nuts, a black liquid will be obtained.

Like powdery mildew, this attack is not fatal for oak. Burning fallen leaves will reduce its spread. In my opinion, individual ink nuts do not reduce the decorativeness of the tree, and, in any case, look very natural.

Gauls- formations on the leaves, stems, buds of plants, provoked by the bites of insects - gall mites. Galls can be red, white, green, spherical or oblong, shiny or dull.

As a rule, the galls themselves are harmless, but they speak of a rather serious plant problem. Normally, galls should not be visible on the plant at all. If outgrowths are found on a large part of the crown of the plant, then this is not normal and must be dealt with.

The mechanism of gall formation is similar to the development of an inflammatory reaction in the human body. When injured, the immune system contributes to the enhanced formation of additional tissues at the site of injury. The same thing happens with plants. By forming galls, plants try to protect the site of the lesion (insect bite). The pests themselves also contribute to the formation of galls, secreting saliva and thereby irritating the plant tissues more and more. 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 a real deformity of the tree.

Among all varieties 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 around the trunk in a circular fashion, the consequences for the tree can be disastrous.

A more common variety are galls that appear on leaves and are caused by gall mites . gall mites- four-legged insects of the arachnid superfamily, 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 and respiration, they feed on the contents of the cell, causing the destruction of plant tissues, various deformations and deformities of leaves and shoots. Most of the life cycle of an insect sometimes occurs inside the galls. For example, a female nutworm insect pierces an oak leaf bud and lays a larva there. A ring-shaped outgrowth begins to develop around the larva. Already after 5-6 months, the developed larva turns into a gall waster, gnaws through the gall that sheltered it and gets out. Adult mites hibernate under the scales of the kidneys. There are up to 1.5 thousand of them in one kidney. In early spring, before bud break, females lay their eggs in the same place where they hibernated. The hatched larvae feed inside the kidneys. During the period of deployment of the first leaves, the larvae turn into females of a new generation, which penetrate near the central vein into the leaf tissue, where they make passages and suck out the juices. At the site of introduction and feeding of mites, leaf tissues grow, and flat yellowish-brown swellings (galls) form on the surface, which later turn black and dry. They can be mistaken for scab spots.

Galls are arranged in rows along the central vein of pear leaves. At apple trees they are scattered throughout the sheet, especially on the underside. With a strong colonization, the leaf blade is covered with a solid black tumor, bordered by a narrow strip of healthy tissue. In the galls, females lay eggs, and the larvae that emerge from them settle on new young leaves and shoots. In autumn, from the end of August - until October, some ticks move under the scales of newly formed buds, feed by sucking out juices, and hibernate. During the season, the pest develops in 2-3 generations. The harm from the tick lies in the fact that the damaged leaves during the growing season dry out and fall prematurely, the annual growth of shoots weakens, and the buds do not develop normally and, as a rule, die. Decreased fruit yield. With strong reproduction of insects, buds and ovaries can be damaged. Particularly common pear gall mite in young gardens.

Galls: control measures and disease prevention.

Galls spoil the appearance of an ornamental plant, reduce the crown area involved in the process of photosynthesis. Gall mites can become sources of infection. The fight against gall mites consists mainly in preventive treatment. If the outgrowths on the leaves have already appeared, then the struggle is difficult. Already damaged hardwood plate is not 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, improperly selected drugs can even spur the activity of the tick, making it difficult to further fight.

Insects have a unique ability to adapt to any poison. In gall mites, such adaptation occurs very quickly. Therefore, it is important to choose an insecticide that acts on a particular type of pest in order to destroy the entire population at once (or in several treatments, depending on the time of treatments, the degree of infection and the selected drugs.

1. Collection and burning of fallen damaged leaves.

2. Spraying trees with 10% karbofos (75-90 g per 10 l of water), 20% celtan (20 g per 10 l of water), 10% isophene (60 g per 10 l of water) in the spring during pinking of buds.

3. Treatment with a suspension of colloidal sulfur (100 g per 10 liters of water) immediately after flowering. Treatments should be repeated in June and July with a strong pest infestation of young gardens.