Chestnut leaf miner - how to fight chestnut trees. Mining moth

A little about the chestnut moth

The chestnut leaf miner is a voracious and therefore dangerous insect that prefers chestnut (green mass of leaves) and related trees as food.
It received the name “miner” because of its characteristic feature of laying eggs in inconspicuous passages hidden in the thickness of the leaf. Such passages, which are made by insect pests, are called “mines” by botanists. The caterpillar of this pest bites into the pulp of the leaf and massively damages it, thereby causing irreparable damage to the tree. Its presence can be determined in the spring by the cloud of small, inconspicuous moths swarming over the trees. Their size can be judged by the fact that with a full wingspan they reach a centimeter. A swarming cloud means that the chestnut moth is celebrating the mating season en masse: the moths are looking for a mate, then the fertilized female lays eggs, after which the larvae hatch and the entire development cycle repeats.

In the photo, this pest is harmless and even some may find it attractive due to its terracotta-red color. But foresters, green farm workers and botanists can give a long lecture about the damage these cute creatures cause to green spaces and how difficult it is to fight them.

The chestnut miner, like most insect pests of wildlife, undergoes cyclical changes in its activity: after a two-year active cycle, when caterpillars destroy entire plantings, a 3-4-year lull occurs, but for those who care about the health of trees, this is not enough comfort. It takes many years for a chestnut seedling to grow into an adult tree, and if control measures are not taken, the chestnut moth will devour the young trees.

One clutch of chestnut moth contains an average of 50 eggs. After a maximum of 3 days, a larva hatches from the egg - a whitish worm. At this stage, the moth can neither be detected nor therefore killed: it is reliably covered by the leaf in which it is located and on which it feeds.

The first, second and third stages of development of the chestnut moth are the growth and development of the larva “at home”, in the mined passage. The microscopic worm can only feed on chestnut juice and is not strong enough to actively move into the depths of the greenery. But as it grows, the course begins to gradually grow deeper.

At the fourth stage, the larva finally turns into a caterpillar, which needs increased nutrition. The entire fifth stage is a frantic devouring of fiber and green mass. It is often at this stage that the moth is noticed. And at this time, you can still save, if not the tree itself, which is covered with insects, then at least the surrounding trees.

The chestnut leaf miner caterpillar needs to grow to enter its sixth and final stage as a healthy insect with an adequate supply of nutrients. This is necessary so that the caterpillar pupates safely before turning into an adult. The closer the pupal phase, the thicker and more phlegmatic the chestnut miner. She loses interest in food because her task is to spin the thread with which she will wrap herself in a cocoon. It is interesting that the caterpillars of this pest do not always do such work; sometimes they are content with cocoons from which moths have already hatched, climb into them and there they transform into a sexually mature individual.

The chestnut moth butterfly makes a hole in the cocoon and climbs out. This happens at the time when flowering clusters appear on the chestnut tree.

Appearance and biological cycle

The harmful insect, with its habits, resembles the behavior of a caterpillar (for which it received the corresponding name). It also gnaws long “corridors” of tunnels in the foliage. It also affects only the inner side of the leaves, leaving the outer layer intact. A plant attacked by moths quickly weakens, withers and inevitably dies.

The pest, having climbed deep inside the leaf, is hidden under the shell of the so-called egg, under the protection of which it will remain until the time comes to turn into a butterfly.

We are used to imagining moths as an unattractive, small, grayish insect. However, the mining moth stands out from the general mass of its relatives, having an unexpectedly bright appearance.

The color of its body and wings can be orange or brick brownish (depending on the subspecies). But not of a uniform shade, but richly decorated with white stripes or spots.

An adult insect butterfly is small in size, with a span of both wings no more than 1 cm. A sexually mature individual is endowed with a long proboscis, with which it sucks life-giving juice from the unfortunate green victim. The egg clutch of one female is up to 50 eggs, and they can be scattered on different leaves of the plant. The larvae emerging from the eggs are wrapped in a dense cocoon, from which they do not emerge to the surface until a certain time, but at the same time actively devouring the leaves and gnawing tunnels in it.

When the time comes for the larva to transform into a caterpillar, it grows legs, with the help of which the pest moves very quickly from leaf to leaf. The small insect has surprisingly powerful mouth jaws; even the toughest foliage is subject to them.

The caterpillar still avoids appearing on the surface. For the time being, it remains within its pre-laid passages, expanding them along the way. After 10-11 days of continuous devouring of the plant, the caterpillar turns into a pupa, and then a butterfly emerges from it. A new biological cycle begins.

The greatest danger of plant damage by leafmining moths is that they settle on plants in entire colonies. Considering that thousands of new pests will emerge from the laid eggs, it is not surprising that the insect leaves behind entire plantations of destroyed plants. And having managed to their heart’s content in one square, turning into butterflies, the colony flies off to another.

The main part of leafminer moth species prefers certain plants:

tomato;
potato;
honeysuckle;
chestnut.

However, there are also “omnivorous” species that do not disdain absolutely any green spaces, including vegetables, flowers, and shrubs. Not only do insects cause harm through their actions, they are also carriers of viral diseases: mosaic, fusarium wilt, etc.

What does the chestnut leaf miner look like?

The Ohrid miner was first recorded only 30 years ago in Macedonia, when this insect pest was considered a relict Balkan species. From a small range in Greece and the Balkan Peninsula, this moth has captured the whole of Europe and is actively moving to the East.

Regardless of theories of origin and whether the Ohrid miner was introduced from East Asia and North America or is native to Europe, catastrophic climate change has caused the once-only-in-the-south pest to spread even into Scandinavia.

The Ohrid miner is a small butterfly with a body length of up to 7 mm and a wingspan of up to 10 mm. This moth miner has a very decorative mottled pattern on its reddish forewings and black dots on its legs.

One female chestnut leaf miner can lay more than 80 eggs. The butterfly's eggs are so tiny that they are almost impossible to notice with the naked eye. They are scattered along the front side of the leaf, near the veins.

Caterpillars go through 6 instars with radically different forms of nutrition and lifestyle. They are also inconspicuous: their size varies from less than 1 mm at the beginning of development to just over 2 mm in the third stage and the “final” 5-6 mm.

The greatest damage is caused by caterpillars in the first five phases - from feeding only on plant sap to switching to eating the tissues of chestnut leaves themselves. Only at the sixth age do they begin to spin and pupate. The pupae of the chestnut leaf miner do not exceed 0.5 cm in length.

This is the most aggressive of all leafminer moth species. For the entire embryonic period, this butterfly needs from 4 days to 3 weeks. The development of the caterpillar takes no more than 45 days in the most unfavorable conditions. In one season during the warm months, Ohrid miners can give birth to three offspring. And no other pest destroys the foliage of ornamental trees as quickly as the Ohrid miner.

Characteristics of the chestnut leaf miner

The chestnut leaf miner is a miniature cutworm. The insect has a flattened body, 5 mm long. The moth's wings are bright brown and have thin silvery-white stripes.

The hind legs of the adult chestnut moth are dark gray with long fringes. Each female lays about 20-30 eggs on the upper side of the leaf.

After hatching from the eggs, the young larvae feed on cell sap, and later eat away the passages in the leaf tissues, forming mines. c has 5 mobile larval stages. The larva is green, translucent, body length - 2-5 mm, consisting of thoracic segments and a number of subsequent abdominal segments.

It overwinters on the horse chestnut tree in the pupal stage inside the leaves that fall to the ground.

Chestnut miner pupae can withstand temperature changes down to -30 °C. First generation butterflies fly from the ground between April and May. In 1 kg of dry leaves there can be up to 4000 individuals.

Female insects lay eggs on young chestnut leaves. One female can lay from 20 to 60 eggs.

Description and appearance

The pest received its name from the geographical location of the area in which these insects were first discovered in the 1980s - the vicinity of Lake Ohrid in Macedonia. The first description of the leaf miner was made by local biologists G. Deshka and N. Dimic.

Initially, the pest was considered a relict Balkan species, but gradually the moth spread northward throughout Europe, from Croatia, Austria (1989), Germany (1994) to the Scandinavian countries (2002) and even to the UK. In Russia, the chestnut moth annually affects trees in the Central regions (since 2005) and the Kaliningrad region (since 2003). According to census estimates, the rate of spread of the pest in some countries reached 100 km/year.

An adult Ohrid miner looks like a small butterfly - the body length is 7 mm, the wingspan is up to 10 mm. The body is brown, the front wings are distinguished by a bright motley pattern and white lines on a brown-red background, the hind wings are light gray. White paws are decorated with black dots. The insect was called a leaf miner because of its ability to make passages (mines) in leaves.

Scientists classify the chestnut leaf miner as a member of the moth family, which is a species of butterfly that can invade the territory of other species. The development cycle of the pest consists of a two-year active period, when the caterpillars emerging from eggs are capable of destroying large areas of planted trees. Then follows 3-4 years of calm.

Development

One of the main features of the development of the chestnut leaf miner and other species of the family is hypermetamorphosis - a method of development in which caterpillars of different ages differ sharply; The caterpillar goes through six phases of development, while the caterpillars of the first - third instars differ from the caterpillars of the fourth and fifth instars in their lifestyle and nutrition, which, in turn, is reflected in their external differences. In the sixth phase of development, the caterpillars spin silk and do not feed.

Caterpillars of the first three phases of development feed only on plant sap (therefore this stage is called the “sap phase”) and form mines in the epidermal layer of the leaf or directly under the skin. Caterpillars of the fourth and fifth phases move from feeding on cell sap to feeding on the tissues themselves of the upper part of the mesophyll of the leaf (the so-called “tissue-eating phase”), while forming more spacious and deeper mines in the leaf. The body of these caterpillars becomes more or less cylindrical, and they acquire well-developed thoracic and abdominal legs. Their head becomes semi-prognathic and their mouthparts are well developed. Caterpillars in the sixth phase of development do not feed (the “non-feeding phase”), but spin silk to build a cocoon. Caterpillars at this stage of development are distinguished by a reduced oral apparatus, a well-developed spinning apparatus and a more fusiform body shape. For 20-45 days, depending on climate and season. According to Gerasimov A.M. (1952), in the genus Camereria

within the sixth phase, two ages are distinguished: in the first, the caterpillars make the lining of the cocoon, in the second - its inner part; Moreover, caterpillars ready to pupate are able to colonize cocoons of previous generations.

Having emerged from the eggs, the first instar caterpillars penetrate under the cuticle into the epidermal layer of the leaf of the host plant. There they begin to absorb the juice, usually making a straight, slightly curved passage along the vein. This passage in the epidermal part is silvery in color, 0.7-1.5 mm long and 0.3-0.5 mm wide. The excrement of the caterpillar in this section of the mine shows a black central line on it (0.05 mm wide at the beginning and 0.08 at the end), which is formed by sections connected by spots. Then the caterpillar forms a spot-like mine with a diameter of 1 mm in the epidermal layer of the leaf, where it begins to molt. At this point, the line of excrement forms a spot-like part of an irregular spherical shape. Sometimes the mottled part of the mine is pale brown. Caterpillars that form such mines can already begin to feed on the juice of the cells of the upper layer of plastid parenchyma.

Caterpillars of the second instar completely switch to feeding on the cell sap of the leaf of the host plant. By the end of the second instar, the larvae form a round mine with a diameter of 2-3 mm. Third instar caterpillars still feed on cell sap in the upper layer of the palisade parenchyma. First, the caterpillars expand the mines in a circle, with excrement completely covering the bottom of the mine, forming concentric black circles. Round mine with a diameter of 6-8 mm, dark. At the fourth instar, the caterpillars switch from feeding on sap to feeding on tissues of all layers of the palisade parenchyma. The average length of the mine is already 16 mm. At the fifth instar, the caterpillars continue to feed on tissues. The mine is from 18 to 31 mm long and from 6-8 to 12-14 mm wide. Sixth instar caterpillars do not feed at all. They first clear the site of exuviae and head capsules of previous instars to build a cocoon and get down to business.

In nature, adult insects appear at the very beginning of chestnut flowering and the appearance of petals. Butterflies hatch (appear) from pupae mainly in the first half of the day. In the afternoon there are single cases of hatching: 52.

Reproduction

Each female chestnut leaf miner lays 20-80 green eggs with a diameter of 0.2-0.3 mm during its life. On one leaf plate on the front side there may be several dozen eggs laid by different females. After 4-21 days (the speed depends on the ambient temperature), larvae emerge from them in the form of white worms, which penetrate deep into the layers of the leaf plate, moving along the veins, and feed on plant sap. The passages formed by the caterpillars are silver in color and up to 1.5 mm long.

The development of the caterpillar goes through 6 phases over 30-45 days and as it grows, its size increases to 5.5 mm. It has a light yellow or greenish body covered with hairs. At the last stage, the caterpillar stops feeding and begins spinning and building a cocoon.

At the next stage, the caterpillar turns into a pupa, which is covered with hairs and has curved hooks on its abdomen. Such devices help it hold on to the edges of the mine, protruding from the leaf, which happens before the butterfly flies out.

Caterpillar of the Chestnut moth.

Nutrition

Insects feed on plant leaves, and the variety is so great that it boggles the imagination. Even conifers are amazed by their miners. Below are lists, far from complete, of quarantine objects, for example, trees:

horse chestnut;
Linden;
holly;
sycamore;
Rowan;
poplar;
thuja;
juniper;
Apple tree;
cherry;
citrus.

Shrubs:

rose;
rose hip;
hawthorn;
honeysuckle;
spirea.

Herbaceous plants:

balsam;
strawberries;
clover;
clematis;
bell;
centaury;
dandelion;
violet, including indoor violet.

Vegetables:

tomatoes;
potato;
cucumbers;
beet;
salad;
parsley;
cabbage;
melons;
and others.

Biological certificate

Why is it called that: miner moth or miner? The fact is that the passages that its larvae gnaw inside the leaf blade, thereby causing undoubted harm to the tree, are called “mines.” According to their biological characteristics, all moths, including leaf miners, are a subspecies of butterflies.

Reference! Most miners specialize in a specific plant, switching to a related one only in the absence of main food.

Description

The egg laid by the female leaf miner moth hatches into a small larva with a spindle-shaped, segmented body. A little later, it turns into a caterpillar with its inherent gnawing apparatus, thanks to which it is able to gnaw fiber, feeding on leaf tissue.

An adult moth insect is a butterfly with a wingspan of up to two centimeters and a variety of wing colors depending on the species to which a particular individual belongs.

Nutrition

horse chestnut;
Linden;
holly;
sycamore;
Rowan;
poplar;
thuja;
juniper;
Apple tree;
cherry;
citrus.

Shrubs:

rose;
rose hip;
hawthorn;
honeysuckle;
spirea.

Herbaceous plants:

balsam;
strawberries;
clover;
clematis;
bell;
centaury;
dandelion;
violet, including indoor violet.

Vegetables:

tomatoes;
potato;
cucumbers;
beet;
salad;
parsley;
cabbage;
melons;
and others.

Development

The age of the moth, the beginning of its reproduction, is familiar to every nature lover who has been close to a light source in the summer. Everyone saw how moths began to fly around the light bulb. Miners are also present in large quantities among them.

Many city dwellers are familiar with chestnut and poplar leaf miners, which parasitize these trees, which are planted to purify the polluted air of the “concrete jungle.” So, during the summer, it is these insects that penetrate apartments and other residential and public premises located near these trees.

Residents of suburban areas observe such years in apple and cherry leaf miner butterflies.

After mating, the female lays up to fifty small translucent eggs on the leaves of the quarantine plant. The larvae appear after a few days and immediately penetrate inside the leaf plate, covering the entrance with an egg shell, a kind of shell.

After this, the growth and development of the larva begins, during which it goes through the molting stage several times.

The first three stages of development, from molting to molting, the larva feeds intensively, gaining height and weight. then, in the fourth stage, the caterpillar emerges and prepares its body for pupation. The fifth stage is characterized by the production of a silk cocoon, after which the caterpillar pupates.

Reference! It should be noted that, depending on the species and climatic conditions, the leafminer moth can go through from one to five generations per season.

If the pupal stage occurs in cold weather, then development stops and in this state the miner goes to winter; the adult insect will appear only in the spring of next year, when the temperature allows.

Types of miners

Let us give examples of some leafmining moths that are most often found in our gardens and vegetable gardens, and also damage green spaces that are easy for cities of the industrial age.

Chestnut miner

One of the worst representatives among miners. The chestnut leafminer moth spread across Europe relatively recently, but forced it to take exceptional control measures. During a season, this pest is capable of producing three generations of offspring.

Tomato

Tomato leafminer spreads on tomatoes and other plants of the nightshade family: potatoes, eggplants, nightshade, and physalis.

Tomato moth

Mining moths appear on tomatoes even in greenhouses. If the infection is not detected in time, you can lose a significant part of the harvest, because the diseased leaf does not fully provide the plant with photosynthetic products.

In addition to nightshade plants, tomato leaf miner can damage pumpkin crops.

Another vegetable pest, the beet leaf miner, parasitizes all types of beets and some salads.

Apple tree

A pest of fruit trees is the apple leaf miner, which also affects pears.

Cherry

Cherry moth is a pest of stone fruit crops. It parasitizes cherries, plums, cherries, and apricots.

Varieties

Tomato

The tomato leaf miner is a pest of plants in the nightshade family, which

include tomatoes, potatoes, eggplants. Common in South American countries, moths are rightfully considered the biggest threat to tomatoes.

Thus, the tomato moth, which appeared several years ago in Europe, in particular in Belarus, was classified as a quarantine object. The moth even penetrates greenhouses, and its caterpillars make double diverging passages in the leaves. The result of their activity throughout the entire vegetative cycle is withering and drying of leaves, a sharp decrease in ovaries and rotting of fruits. Multiplying quickly, tomato moth can destroy a significant part of the crop.

Chestnut

The chestnut leaf miner is a pest of urban horse chestnut plantings. The authorities of European cities spend a significant portion of their budget on restoring plantings that were destroyed by moths and on prevention.

First noticed in the 80s of the last century in Macedonia, the chestnut moth is confidently capturing new territories.

Apple and cherry

Apple and cherry leaf miner is a pest that chooses to attack apple and cherry orchards. After waiting out the winter in the folds of the bark, the moth lays up to hundreds of eggs on the budding leaves. Caterpillars can live in a whole colony above the head of an unsuspecting gardener, since until the last gnawed leaf appears intact.

The presence of moth caterpillars can sometimes be noticed only by the appearance of cocoons on the bottom of a withered leaf.

What harm does the chestnut leaf miner cause?

Chestnut leaf miner (Cameraria ohridella), Ohrid leaf miner, chestnut leaf miner is the main pest of horse chestnut trees with an extremely rapid rate of spread, a species of butterflies in the category of moths.

Caterpillars “mined” the leaves from the inside and lead to their premature death and fall, weakening the tree and causing a catastrophic loss of decorativeness and endurance, resulting in damage from frost, other pests and diseases.

The chestnut leaf miner is activated and first appears on chestnut trees even before the mass blossoming of leaves, when the petals on the flowers begin to open. The Ohrid miner is usually active for two seasons in a row. Infestation of trees this year is almost a guarantee that next spring the affected area will be even larger.

But many scientists note that after a peak of activity for several years, the pests almost disappear, presumably moving to new territories.

The massive shedding of limp, lifeless leaves by chestnuts in July and August, which has so often been observed in cities in recent years, is the result of defeat by the Ohrid miner. The main symptom is leaf wilting. Hundreds of yellow or reddish traces appear on their surface - “min” (up to 700), which the caterpillars leave in the epidermal layer, feeding on juices and cells.

The leaves die quickly, the lesions grow more and more, and the green areas completely disappear. It is very difficult to diagnose an infection - the spots resemble both rust and fungal infections. The “work” of miners inside the leaves can be recognized only by the absence of a thin yellow border and black bubble spots (pycnidia) on the mines. And, of course, due to the accelerated fall of leaves.

The chestnut leaf miner causes such irreparable damage to trees that most of the ornamental plantings of horse chestnuts are in danger of dying:

Due to the rapid loss of green mass, chestnuts do not accumulate nutrients and cannot properly prepare for wintering; most often they partially freeze out even in mild winters.
The trees partially dry out and produce new leaves very slowly.
Endurance suffers - weakened chestnuts become defenseless against leaf-eating pests that attack shoots and trunks. Fungal diseases spread to them ten times faster.
Even with primary damage, such chestnuts completely lose their decorative properties. If in private gardens you can fight to save them, then in urban landscaping where aesthetics are critical, mature trees almost always require replacement and immediate preventive measures.

Without measures to stop the spread of the pest and treatment, trees affected by the Ohrid miner may die within a few years.

Protecting plants from leaf miners

Protecting plants from leaf miners includes several techniques.

Selection of resistant plant species and varieties. Miners do not colonize all plant species of the same genus. Thus, on the chestnut chestnut, the larvae of the chestnut miner die at a young age, and the small-flowered chestnut is not colonized by this pest at all.

Inspection of plants. The sooner damage to plants by leaf miners is detected, the less harm they will cause. Remember that leaf miners can be spread by potted or cut flowers.

Sifting of the soil before use for greenhouses and potted plants is carried out, since the pupae of many miners overwinter in it.

Insulating indoor plants with fine-mesh mesh when placed on a balcony or in a garden allows you to protect them from wind-blown leafminers.

Hanging yellow plates (boards, pieces of plastic), smeared with glue, in greenhouses and in open ground along rows of plants at the level of the bulk of the foliage, in order to catch flies and moths during their summer.

Applying adhesive belts to trunks immediately before the start of the summer of miners.

Removal of infested leaves or parts thereof manually followed by destruction.

Removing fallen leaves is the simplest and most environmentally friendly measure to protect trees from leaf miners that overwinter in fallen leaves. The leaves must be raked without damaging them to prevent the pupae from spilling out, and then composted rather than burned.

Digging up tree trunk circles and loosening the soil under the crowns.

Washing off leaf miner moths with a stream of water from a tree trunk during the mass summer of each generation.

Application in chemicals. Insecticides to protect ornamental plants from leaf miners are used by spraying foliage, soil under plants, and also by injection into the trunk. However, injection into the trunk is expensive and creates conditions for pathogenic microorganisms to penetrate the tree, and the introduction of insecticides into the soil is dangerous for many of its inhabitants. If there are several generations of miners, several foliar sprays are carried out per season.

Mining moths are small butterflies

, which includes several families of small moths with a similar lifestyle and feeding caterpillars that
mine plant foliage
, causing it to fall off.

Distinctive characteristic

These
insects
have
a mine
, which differs in each species in shape and location in the leaf.
They may be in the form of a tunnel
, a spot, or a tunnel with a spot at the end.

A larva emerging from an egg laid on the inside of a leaf

The tomato moth
has
a segmented,
spindle-like shape and a pale milky color
.
Over time, the larva develops and becomes a caterpillar with movable limbs located on the chest and abdominal parts. The caterpillars
also have a well-developed mouthparts, thanks to which they easily
gnaw through
the dense fiber
of the plant
.

An adult insect is quite large in size

– the full wingspan reaches 2 centimeters, which,
coupled with the catchy color
, depending on the specific species,
makes it noticeable
.
The pest develops quickly and in 1 season 2 generations of leafminer moth caterpillars appear
: at the beginning of June and at the end of July or beginning of August.
The second generation
of insects on the same plant is several times
larger than the first
.

How to get rid of moths

There are various methods to combat chestnut miner. Mainly 3 control methods are used: chemical, biological or alternative.

It is advisable that a suitable method be selected by a dendrologist.

Preparing chestnut for use

The first stage of the fight against chestnut moth includes the following steps:

all fallen or damaged leaves are removed and burned;
carefully inspect neighboring branches in order to detect new parasitic passages;
young seedlings are covered with non-woven fabric during the period when active flight of insects is expected;
attracting insect predators to gardens and greenhouses that eat larvae and adult moths;
spraying plantings with rapeseed oil;
eliminating insect colonies from chestnuts with a strong jet of water.

The mining moth does not choose all types of horse chestnut as an object of parasitism. Organizations responsible for landscaping should carefully select plant varieties that are not of interest to insects.

It is easier to prevent the appearance of a pest than to then try to get rid of it.

Biological control methods

The dendrologist will tell you how to fight the chestnut moth using biological means.

This parasite itself becomes food for some representatives of birds or insects:

tits, starlings, sparrows, as well as about 20 other species of birds consider the chestnut miner as an element of their diet. When these insects attack chestnut trees in the spring, it is recommended to attract as many of these birds as possible to public gardens.
Many insects also actively feed on chestnut leaf miners. Among them: spiders, ladybugs, real wasps, ants, tree bugs.
Trichogramma occupy a special place among the natural enemies of moths. These are beneficial insects (entomophages). The female Trichogramma lays her eggs in the eggs of the pest host. The eggs hatch into ichneumon ichneumon larvae, which feed on the leaf miners, gradually killing them.

Since parasites themselves are parasites and it is difficult to predict what their increased colonization will lead to, therefore this method is used extremely rarely.

Chemical method

Various chemical agents have been developed to combat adult leafmining parasites, as well as their larvae. Their main disadvantage is increased toxicity and danger to human health.

Chestnut trees often grow near homes or in areas where people frequently walk, so using chemical insecticides can be very dangerous. It is also quite difficult to spray trees due to their large size.

Often, during chemical treatment, a substance dangerous to the pest ends up on only one part of the tree, while the second is not affected by toxic substances. Against this background, the parasite migrates to the healthy half of the tree and after some time still destroys it.

Therefore, this method of combating chestnut miner is considered ineffective and is used extremely rarely.

Biologists, together with chemists, continue to develop effective control methods. They came up with injections that are made into a tree trunk. Numerous studies confirm the effectiveness of this technique.

With the help of stem injections it is possible to get rid of both chestnut leaf miners and other insects that parasitize trees. This insecticide poisons the tree sap and kills parasites.

Moth traps

Pest control can also be carried out using a chestnut moth trap. They are pheromone dispensers. Mass catching of the chestnut miner is carried out directly in the lesions.

It is recommended to hang 2 traps on each tree. They are placed asymmetrically on different edges of the crown.

For preventive purposes, 1 trap is hung per 10 trees for monitoring. Dispensers are placed in public gardens with an increased likelihood of pests appearing before the beginning of chestnut flowering at a height of 1.5-2 meters from ground level.

Be sure to evaluate the contents of the traps 1-2 times a week.

Efficiency of use of funds

The chestnut leaf miner does not tolerate injections made inside the trunk. This method is effective both for prevention and for eliminating the pest if it has already attacked the plant.

In the first case, the miner prefers not to attack such trees; in the second, the larvae die almost immediately after introducing the chemical into the trunk.

Such injections are safe for people, animals, and also for the plant itself.

If classical insecticides are used in large dosages, plant oppression may occur.

And chestnuts tolerate stem injections very well. But this method has one significant drawback - the cost of the drugs is very high.

Fame drug

Fame is an effective contact drug against Tuta Absoluta, which is capable of containing the pest population for 1.5-2 weeks. It does not work when applied at the root. The drug Fame, although it has a different active ingredient (flubendiamide), affects the same mechanisms in the pest’s body as Coragen. There is cross-resistance between these two drugs, which should be taken into account. Takomi (Takomi), Belt (Belt), Fame, Fenos (Fenos) - these are all names of one insecticide with the active substance flubendiamide. Therefore, treatments with all these drugs have the same effect and it is not recommended to alternate them with Coragen.

Plant protection

The fight against leafminer moths begins with preventive plant protection. There are many agrotechnical techniques that can be used to reduce the damage caused by these pests to crop plants.

Autumn harvesting of leaves and then placing them in compost.
Selecting plants that are not damaged by leaf miners. Biologists usually cite chestnuts as an example; the small-flowered species is not affected by moths at all, but the leaves of the meat-red species kill the larvae.
Sifting the soil for seedlings and planting holes will help get rid of pupae.
The use of predatory ichneumon insects in greenhouses.
The use of adhesive tapes, to which butterflies can stick during the summer.
Manual collection of affected leaves.
Washing butterflies from leaves under the pressure of a water jet.

Plants that are affected by the chestnut moth

Despite its name, the chestnut leaf miner does not affect only chestnut trees, and it does not spread equally to all horse chestnut trees.

The Ohrid miner is the main pest of white-flowering horse chestnuts, in particular common and Japanese. Compact hybrids suffer greatly from it, the degree of resistance of which varies depending on the conditions and characteristics of selection.

Certain varieties of horse chestnut are unattractive or even destructive to this species of butterfly. Thus, on Chinese, Californian, meat-red, Indian, Assamese, and small-flowered horse chestnuts, the caterpillars die in the early stages of development.

Choosing the right species and checking resistance to Ohrid miner for a specific plant when purchasing is the best solution. After all, vulnerable varieties and species have more and more resistant competitors every year.

In addition to chestnuts, the Ohrid miner is also found on several ornamental species of trees and vines:

five-leaf maiden grapes;
decorative maples, especially white and Norway maples.

One effective method of creating an unfavorable environment for chestnut leaf miners is to install “insect hotels.”

Mining moth on cherries and other plants: control methods using the example of one crop

Let's say miners are attracted to the cherry trees in your garden. If the lesions are still minor, you can try to cope with them without the involvement of specialists, using gentle methods. For example:

collect and burn damaged leaves, including those on neighboring trees;
hang yellow glue boards: this color attracts insects, and having landed on a layer of glue, the insect will not be able to take off again and will die. The boards need to be changed as the surface is filled;
introduce insect predators that feed on pests, such as ichneumon wasps;
miner moths on cherries will feel uncomfortable if the tree is regularly treated with rapeseed or mustard oil;
you can knock pests off a tree by pouring a stream of water under strong pressure;
young trees are sometimes covered with non-woven material, which protects the seedling from attacks by mining pests. In the same way, you can, by the way, protect garden beds from moth invasions.

If such methods do not bring results, you will have to turn to insecticides for help. Pyrethrum-based preparations are considered the most effective. However, it is quite toxic, so a number of rules should be followed when working with the composition:

protect exposed areas of the body with a mask and gloves;
spray in the morning and evening during the period of minimal activity of insects that destroy miners;
carry out the procedure at least five times with breaks of 3-5 days.

Considering that moth larvae are quite tenacious, they can continue their development even after getting into the soil. Therefore, if the area is heavily infected, it is recommended to deep water the beds with a preparation containing pyrethrum.

The main measures to combat leafminer moths on chestnut trees are similar to those described above. But there are also differences. Considering that chestnuts, as a rule, are planted for decorative purposes in places with large crowds of people, namely, in park areas, alleys and public gardens, it is better to replace spraying with insecticides with intra-trunk injections - this method of treatment will cause less harm to the environment.

It should also be borne in mind that miners adapt quite quickly to new conditions, so during prolonged use of the same insecticidal preparation, its effectiveness may decrease. In this case, it is worth changing the product to one that is similar in effect, but based on a different component.

External signs of damage

When a leafminer moth begins to lay eggs, this moment is easy to track. Because it begins to swarm around the trunks and stems of plants. One leaf miner can lay up to fifty small eggs. After just a few days, larvae will appear, which will not come to the surface, but will go deeper into the leaf, trunk or stem of the plant. That is, the larva is located inside the leaf and is completely hidden from the outside world. Because of this, controlling leafminer moths is a complex process.

External leaf lesions depending on the stage of development of the leaf miner:

The larva feeds on plant juices and makes passages inside the leaves;
When the larva transforms into a caterpillar, it begins to feed on leaf fiber, the passages become wider and more noticeable;
In the final phase of development, the caterpillars stop feeding, but begin to spin silk for the future cocoon.

Larvae or caterpillars of leafminer moths cannot hibernate and overwinter; this is only possible for pupae that are reliably protected from frost in the cocoon.

Signs of damage and prevention

It is easy to distinguish a chestnut tree on which a colony has lived for a long time. Its leaves are completely or partially covered with dry areas, holes, and ulcers. It is difficult to detect a sign of a colony that has just settled, since leaf damage is still almost invisible.

Prevention may be as follows:

use chemicals by placing them in the trunks;
collect fallen leaves and burn;
spray chestnut trees and their leaves with spring oils;
cover chestnut plantings with canvas;
get rid of insects by knocking them down with a strong stream of water.

Sources

https://KlopSOS.ru/mol/kashtanovaya-miniruyushhaya/
https://www.botanichka.ru/article/kashtanovaya-miniruyushhaya-mol-metodyi-profilaktiki-i-borbyi/
https://OVreditelyah.ru/mol/kashtanovaya
https://dr-dez.ru/mol/miniruyushchaya-na-kashtanah.html
https://beetlestop.ru/miniruyushhaya-mol/
https://parazitdoma.ru/mol/kashtanovaya
https://sichovka.ru/vrediteli-rastenij/kashtanovaya-mol.html
https://apest.ru/mol/vidy-moli/kashtanovaya-miniruyuschaya-mol/

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Chestnut miner

Recently, horse chestnut (Aeskulus hippocastanum) has become increasingly used in landscaping. The plant is winter-hardy, tolerates city conditions well and is suitable for alley, group and single plantings. However, at the moment, chestnut plantings are under threat due to the mass reproduction of a dangerous quarantine pest - the chestnut leaf miner (Cameraria ohridella Deschka & Dimic).

Macedonia – Russia

The chestnut miner first became harmful in Macedonia in 1986. Described as a new species by Yugoslav entomologists in 1986 based on collections carried out in 1984–1985 in the area of Lake Ohrid (Macedonia).

In 2002, the pest appeared in Ukraine, in Lvov, in 2003 - in Kyiv, as well as in the Kaliningrad region, in 2007 it was first discovered in Minsk. The pests entered Moscow in 2005. To date, the chestnut miner has been registered in most countries of Central, Eastern and Western Europe.

The chestnut leaf miner, or chestnut leaf miner (Cameraria ohridella Deschka & Dimic), belongs to the order Lepidoptera, suborder Microlepidoptera, family of moths Gracellaridae, genus Cameraria.

The pest and its victims

This pest causes serious damage only to the common horse chestnut. Minor damage was observed on the naked squash (A. glabra). In the Moscow region in 2007, numerous pest mines were identified on the chestnut tree and single mines on the meat-red tree. In single, small-sized mines on Norway maple, the caterpillars of the chestnut leaf miner died without completing their development.

Damage caused by the larvae of the chestnut leaf miner significantly reduces the decorative value of plantings and contributes to their weakening.

Butterflies of the chestnut leaf miner moth are small, with a wingspan of 6 mm. The fore wings are lanceolate, variegated, silver-ochre in color, with three transverse blurred white bands, convexly curved towards the apex with uneven edges. The hind wings are ocher-gray with a silvery tint, without a pattern. Along the perimeter of the wings there is a long whitish-gray fringe.

The mass flight of butterflies occurs in May, coinciding with the flowering of the chestnut tree.

Apparently, the wintering characteristics of the moth ensured its wide distribution with planting material in numerous urban landscaping sites and private areas.

Mining moth butterflies Mine on a horse chestnut leaf Multiple mines on a horse chestnut leaf

Life cycles

Females lay eggs one at a time on the upper surface of leaf blades, mainly near the veins. The eggs are very small; the female covers each of them with a transparent secretion, which dries over the egg in the form of a thin film. Embryonic development lasts 7–10 days. The hatched grayish-green caterpillars chew out a cavity in the palisade fabric. At first, the mines are small, in the form of brownish round spots with a darker spot in the center and a lighter border along the edge. As the caterpillars grow, the mines become elongated and, if densely populated, can occupy almost the entire leaf blade. Sometimes there are several tens of mines on one sheet.

During feeding, the caterpillars go through four instars, as well as two instars while in the pupal chamber in the mine, where pupation occurs. After 10–12 days, in the second or third decade of July, the butterflies fly out. In the conditions of Moscow and the Moscow region, the butterfly gives two full generations. In 2008, the region saw the beginning of the third generation.

Overwintering of the second generation chestnut leaf miner moth takes place at the pupa stage in fallen leaves or as a butterfly huddled in bark cracks in the butt part of trees. Apparently, the wintering characteristics of the moth ensured its wide distribution with planting material in numerous urban landscaping sites and private areas.

Control measures

To reduce pest numbers it is recommended:

in autumn, collect and remove mine-damaged leaves from plantings;
in the spring, during the flight of butterflies from their wintering place, wash the butt part of the trunk with a strong stream of water;
in the summer, during the flight of second-generation butterflies, it is advisable to re-wash the crowns and trunks of horse chestnut to prevent further settlement and mass reproduction of butterflies.