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 galls . 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.
What are galls and where are they common?
Galls are spherical formations on leaves that appear as a result of insect bites. They are harmful to agriculture, but are actively used in folk medicine. The article will talk about the features of education, the principles of their use and methods of struggle.
Ball-shaped growths on the leaves, with a diameter of one and a half to two centimeters, are ubiquitous. These are abnormal cellular neoplasms on the leaves, shoots and even roots of plants.
They are most often found on oak leaves. In Mesopotamia and Asia Minor, the so-called “gall” oak is common. New growths on its leaves are actively used in medicine.
These spherical growths on oak leaves are formed as a result of the laying of oak gall moth eggs.
Galls are now ubiquitous and can affect any foliage plant. Even indoor flowers are not out of danger.
table of contents
- 1History of cecidology
- 2Living organisms that produce plant galls
- 3Production of plant bile
- 4 Classification of various forms of gall 4.1 Organoid galls
- 4.2 Histoid galls 4.2.1 Felt galls
- 4.2.2 Curls and folds of leaves
- 4.2.3 Sac galls
- 4.2.4 Wall galls
- 4.2.5 Bone marrow galls
- 7.1 Individual evidence
Mechanism of gall formation
The process of formation of growths resembles the process of spread of inflammatory processes in the human body.
In addition, the formation mechanism has its own characteristics:
- A gall forms at the site of injury (insect bite);
- The growth can form not only on the leaves, but also on all other parts of the plant;
- The size of the galls can vary: from a few centimeters to huge growths.
There are several types of insects whose bites can provoke development, the most common are gall mites:
- They belong to the superfamily of arachnids and the order of acarimorphic mites;
- They have small body sizes: from 0.1 to 0.6 mm;
- No sense of smell;
- By biting a plant, they feed on it, destroying the tissue structure of the leaf.
In some cases, the formation of galls is caused not only by the presence of a bite. So, for example, a female gall moth lays a larva in an oak leaf bud, which there carries out a cycle of transformation into an adult. As a result, a growth forms on the leaf, surrounding the larva - a gall.
Location Features:
- Galls on pear leaves are arranged in rows parallel to the central vein of the leaf;
- On the leaves of the apple tree, they are located all over the leaf. There are especially many of them on the underside;
- Galls on willow leaves are represented by chains of convex growths on both sides of the leaf.
Do not underestimate the harm of the gall mite. Affected leaves do not go through the full growing season, but dry out and fall off prematurely.
In addition, the gall mite can infect not only leaves, but also young shoots and buds, which negatively affects the level of plant productivity.
History of cecidology
Although the economic benefits of some galls have long been known to man, some gall apples in the oaks were used, for example, for the production of iron gall ink and as a supplier of tannins to the tannery; scientific research in this area of biology only began in the late 17th century. The first scientific description of the phenomenon of gall formation in plants was Hippocrates Cos; however, he considered the observed growths only to be specific to certain plant fruits and did not recognize any connection between parasites and the formation of galls.
The first Marcello Malpighi led with his book Idea Anatome Plantarum
breakthrough in cecidology.
There he described 60 different forms of gall in the chapter De Gallis
and for the first time attempted to systematize and define the phenomenon of gall formation.
How are galls used in medicine, what are they made from?
The galls are collected in the last month of summer. Harmful to plants, they are widely used in folk medicine.
So, for example:
- Gall tincture is used to rinse the mouth for fluxes. Also used to treat frostbitten parts of the body;
- Tincture mixed with vinegar is used to treat diseases of the ENT organs;
- It is known to have an activating effect on the hair growth process;
- Helps accelerate the healing of cracked lips and burns;
- They are also used to treat eye ulcers (for both external and internal use);
- Used to strengthen the digestive system;
- Infusions are taken internally for the treatment of diarrhea;
- Used as an adjuvant in the treatment of tuberculosis;
- Lotions and rubs from the infusion of galls are used to treat various diseases of the epidermis: insect bites, lichen, ulcers;
- Helps in the treatment of leucorrhoea.
Brewed dried galls are taken internally.
For lotions use a decoction of:
- One glass gal
- Liter of boiled water
The mixture is boiled for five minutes, after which the broth should settle and be filtered.
Galls on the leaves are widely known in folk medicine. Tinctures of these formations are used both internally and externally.
sources
Individual evidence
- See, for example, Jürgen Martin: "Ulmer Wundarzney".
Introduction - Text - Dictionary on the monument of German special prose of the 15th century. Königshausen and Neumann, Würzburg, 1991 (=
Würzburg Historical-Medical Research.
Vol. 52), ISBN 3-88479-801-4 (also Würzburg medical dissertation, 1990), p. 129 (
galla
). - Plant galls and caecidology: What are plant galls?
cecidology.blogspot.com - Rolf Beiderbeck, Ingo Koevet: Plant galls along the way.
Origin and destination. ISBN 3-440-04751-2.
literature
German speaking
- Heiko Bellmann: Bees, wasps, ants. Hymenoptera of Central Europe. Cosmos (Franckh-Kosmos), 2005, ISBN 3-440-09690-4.
- Ernst Küster: Plant galls. Leipzig 1911
- Rolf Beiderbeck and Ingo Koevet: Clockwork Gauls along the way - origin and purpose. Cosmos Verlag, 1979, ISBN 3-440-04751-2.
- Herbert Boer: Tables for identifying galls (zoo and phytocecidia) on plants of Central and Northern Europe.
Gustav Fischer Verlag, Jena, 1964/65. - G. Jerome: Contribution to the study of European zoocecidia and their distribution. Gross, Bart and Co., Breslau 1890.
- Karl Cech: New division of the Gaul plant. Gross, Barth & Co., Düsseldorf 1858, urn:nbn:de:hbz:061:1-115216.
English speaking
- Ron Russo: A Field Guide to the Clockwork Galls of California and Other Western States. University of California Press, London, 2006, ISBN 0-520-24886-4.
- Arnold Darlington: A Pocket Encyclopedia of Colored Plant Galls. Blandford Press, Dorset, 1968, ISBN 0-7137-0471-3.
- Margaret Redfern, Peter Shirley: British Plant Galls: Identification of Galls on Plants and Fungi. Field Research Council, Shropshire 2002, ISBN 1-85153-214-5.
Variants of manifestations
About 100 species of gall mites are known in Russia, and each plant has its own parasites. As a result of metabolic disturbances, the galls become enriched in tannins. This applies primarily to oak, sumac or pistachio galls.
Interesting things in nature
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 - 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.
Source
Elm disease - scale insect
Elm diseases are not limited to Dutch infection. There is another unpleasant disease - scale insects. If you see growths on the branches of an elm, then this is precisely the scale insect. This is an insect that looks like small pimples on elm branches.
>Schitovka is a sucking pest about 2mm in size. Today, a distinction is made between the common and brown scale insects. The scale insect got its name due to the fact that, having attached itself to a leaf blade, it covers it with a waxy shield that is completely unlike an insect. If you have very sharp eyesight, you can sometimes see how hatched young scale insects crawl away from the mother’s shield along the leaf in search of a place of refuge. At this stage, the scale insect is called a stray.
Scale insects can be diagnosed by the formation of yellow or whitish spots on the leaves. In the first case, the common scale insect works, in the second - the brown one. Scale insects can severely damage a tree by clinging to fruits, leaves, branches and tree trunks and disrupting sap flow. If the damage is severe, the trees wither, stop bearing fruit and eventually die. If several trees in the garden are severely affected by scale insects, it is recommended to uproot them and burn them.
The scale insect spreads with planting or grafting material. Therefore, when purchasing it, you need to carefully monitor that there is no pest on the seedlings.
Measures to combat scale insects
In early spring, before the buds open, it is better to treat elms with insecticides. Trees need to be re-sprayed when strays appear. This treatment can be combined with treatment against other pests.
If the tree is small and manual control is available, then the plant can be washed with soapy water and the affected leaves can be cleaned with a brush once a week.
If you find signs of disease on your plants, you may need to consult a forest pathologist. Call us, we will help protect your trees!
Source
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 galls . 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.
Elm grass aphid, red gall elm aphid, sorghum aphid
Elm-grass gall aphid
A sucking insect of the order Homoptera, family Aphididae. The species is dioecious. In the spring, galls form on the upper side of elm leaves from the stings of aphids. Parthenogenetic females live inside the galls. In summer, female settlers fly out to various cereals (corn, barley, wheat, grasses). They form colonies with wingless generations living on the roots.
In autumn, winged females fly to woody plants. Fertilized females of subsequent generations lay one egg on the bark of trees. Produces several generations per year.
Damages the roots of many annual and perennial grasses. In the photo there are specimens from the roots of feather grass.
In grasses that are wingless from roots, the body is oval, 1.9-3.0 mm long, with 6 rows of glandular groups on abdominal tergites I-VI and 4 rows on VII. Orange-yellow, whitish-yellow or red, covered with a light waxy coating. The antennae and legs are short. The antennae are 5-segmented (rarely 6-segmented). The eyes are usually 3-faceted, sometimes there are more facets. The tarsi are 1-segmented. There are tubes. It develops dioeciously: from galls on elm leaves (galls are smooth, stalked, shiny, without hairs and spines, green, greenish-pink, red) and migrates to the roots of wheat, barley, oats, millet, corn, rice and many wild cereals. Sometimes it develops incompletely (overwinters on cereals). In the Far East, no harm has been established. – Russia Primorsky Krai; Siberia, Europe Part. – Transpalearct, brought to North America.
Red gall elm aphid
Tetraneura coerulescens Pass. (Homoptera, Aphididae)
Wingless viviparous female up to 2.5 mm long, externally reminiscent of T.ulmi L., ovoid-oval, widest in the posterior half, strongly convex; yellow with a waxy coating; the head is brown. Spreading. CIS: forest-steppe and steppe zones of the European part, Caucasus, Central Asia. Southern Europe, Middle East.
The species is dioecious. In spring, galls form on the upper side of birch bark leaves from aphids. Parthenogenetic females live inside the galls. In summer, female settlers fly out to various cereals (corn, barley, wheat, grasses). They form colonies with wingless generations living on the roots. In autumn, winged female moths fly to woody plants. Fertilized females of the subsequent sexual generation lay one egg on the bark of trees. Produces several generations per year.
Sorghum aphid
Wingless viviparous female up to 2.5 mm long, elongated oval; grayish-green (gray), with long black nipple tubes, antennae and dark spots on the sides; nipple tubes are long. Spreading. CIS: southern European part, Caucasus, Central Asia. The species has a circumtropical range. Maliciousness. In addition to cereals, it causes severe damage to other cereal crops (corn, sorghum, rice, sugar cane). The transfer of viruses, including barley yellow dwarf, has been noted (Schmelzer and Spaar, 1977).
Distributed in steppe and forest-steppe zones. Damages rice, sorghum, corn and other cultivated and wild grains.
Wingless parthenogenetic female of the species, female-shaped, whitish-green; head, antennae, legs, tubes, tail and transverse stripes on the abdomen are black-brown; body covered with sparse short hairs, antennae less than half the length of the body; the tubes are small, with a finger-shaped tail no larger. The winged female has a black-brown head and chest, and the tubes are shorter than those of the wingless female. Development is incompletely cyclical.
Wingless parthenogenetic females and larvae overwinter on wild cereals, from which they spread to rice fields in spring and summer. The fields are populated gradually, starting from the edges to the center. The number of aphids in the center of the field reaches its maximum in early July.
Aphids settle on the underside of leaves, in the axils, first on the tops, and then on the entire plant. When irrigated, these pests appear first along canals and on shafts, as well as on plants that are weakened due to disturbances in the water or nutritional regime. In August-September, winged insects settle on cereal weeds, where larvae and adults overwinter.
Damaged leaves first lighten, then turn yellow, and when the pest multiplies massively, they curl and dry out. The pest is a carrier of viral diseases.
Source
Who lives in “oak apples” (ink nuts)?
If oak trees grow in the places where you live, then you have probably noticed that sometimes quite large green balls swell on the lower part of their leaves, some of which by autumn can boast red sides. Sometimes a whole bunch hangs on one leaf. They are called " oak apples ", " oak grapes ", ink nuts , and scientifically - galls or cecidia. Where do they come from and why are they called that? Apples, grapes and nuts are understandable in appearance, although they do not differ in edibility and taste, because oak fruits are acorns. But why ink? Ink has been made from them for more than two thousand years, dating back to the times of the Roman Empire. Oak galls contain a large amount of tannins - natural polyphenols, which form a complex compound with iron salts, colored black, which can be used as ink. That is why this ink is called ferrous or iron gall ink. The growth of these “balls” is caused by a very small fly from the Hymenoptera family - the common oak gall moth , also known as the apple gall moth (lat. Cynips quercusfolii), although there are several more similar species from the gall moth superfamily (cynipoids). She pierces a vein on the underside of an oak leaf and lays an egg there. The larva hatches from it and actively secretes special substances into the leaf tissue - auxins, which cause local proliferation of plant tissue and the growth of new growths - galls. The larvae have a double benefit from this - there is food nearby and reliable protection around them (somewhat similar to the behavior of the pennies). The photo shows both the living chamber and the colorless larva itself. As you can see, the size of the insect is significantly smaller than a large ball of gall, consisting of spongy, as if foamed tissue. In autumn, the galls fall off along with the leaves. The larva, having turned into an imago (adult insect), gnaws its way out. She now has wings, can fly, find a mate and lay eggs to give birth to a new generation of insects.
Ink nuts are a particular type of galls formed by the larvae of a number of insects of the gallworm family (Cynipidae) on young branches and leaves of some species of oak (Quercus). They are porous formations of round or oblong shape in the form of growths with a diameter of 1.5-2 centimeters or more. Ink nuts may form clusters on the affected leaves. Contain tanning agents (up to 70% of dry weight). The color can be greenish-yellowish, yellowish-white, yellowish, often with a red side. Because of their shape and color, they are called "oak apples" in English.
The structure of the gall is soft and loose, the internal contents are porous. In the very center of the gall there is a small chamber with a diameter of up to 5-7 mm, inside which the larva develops. Nutcrackers use an ovipositor to lay eggs one at a time into the pulp of the leaf. This causes increased growth of surrounding tissues, resulting in the formation of a gall. The egg hatches into a larva, which eventually develops into an adult insect. The adult makes a passage in the pulp of the gall and emerges through it. In Europe, the main primary sources of inknuts are the common oak nutworm (Cynips quercusfolii) and Biorhiza pallida, and in North America - the species Amphibolips confluenta and Atrusca bella.
Ink nuts got their name because in the old days they were used to make ink for writing. Inknuts contain a lot of tannins, which are natural polyphenols (substances that have several –OH groups attached to a benzene ring). Tannins form a complex with iron salts, colored black, and this is what the ink was based on. Based on the method of preparation, this ink was called ferruginous or iron gall.
Ink nuts have been known and used in ink production since at least Roman times. For a long time, since the Middle Ages, this ink was standard for use in writing; they were most common from the 18th century until the mid-20th century due to the gradual increase in literacy. To make ferrous ink, galls were infused in an acidic solution and iron filings were added. The process lasted up to a month. In order for the ink to “fit better” on the paper, cherry resin - gum - was introduced into its composition. The ink obtained in this way was quite durable - it faded little in the light and was waterproof. Despite the good resistance of the ink to fading and washing, due to the presence of active substances in the composition, they cause destruction of the paper.
