Chestnut Mining Moth - Methods Of Prevention And Control. Ohrid Miner. Description Of The Pest. Photo

Table of contents:

Chestnut Mining Moth - Methods Of Prevention And Control. Ohrid Miner. Description Of The Pest. Photo
Chestnut Mining Moth - Methods Of Prevention And Control. Ohrid Miner. Description Of The Pest. Photo

Video: Chestnut Mining Moth - Methods Of Prevention And Control. Ohrid Miner. Description Of The Pest. Photo

Video: Chestnut Mining Moth - Methods Of Prevention And Control. Ohrid Miner. Description Of The Pest. Photo
Video: Horse Chestnut Leaf Miner Moth 2023, June

Among the pests enjoying climate change, no insect has spread as widely as the chestnut miner moth. In recent years, it has caused a lot of trouble both in urban landscaping and the owners of private gardens. After all, compact varieties of horse chestnuts are becoming more and more popular in the design of large areas, and maple and maiden grapes, loved by the Ohrid miner, do not lose their leadership positions at all. It is possible to fight the chestnut moth, but the loss of decorative plants cannot be avoided even with timely control measures. And this is not an easy process.

Chestnut miner moth - prevention and control methods
Chestnut miner moth - prevention and control methods


  • What harm does chestnut miner moth cause?
  • What does a chestnut miner moth look like?
  • Plants that are affected by the chestnut miner
  • Methods for dealing with chestnut miner

What harm does chestnut miner moth cause?

Chestnut miner (Cameraria ohridella), Ohrid miner, chestnut miner - the main pest of horse chestnuts with an extremely fast spreading rate, a species of butterflies of the category of motley moths.

Caterpillars "mine" 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 frost damage, other pests and diseases.

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

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

The mass dropping of sluggish, 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 - "mines" (up to 700), which leave caterpillars in the epidermal layer, feeding on juices and cells.

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

The chestnut miner moth causes such irreparable harm to trees that most of the ornamental plantings of horse chestnuts are in danger of death:

  • 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 dry out partially and release new leaves very slowly.
  • Endurance suffers - weakened chestnuts become defenseless against leaf-eating and pests affecting shoots and trunks. Fungal diseases spread on them ten times faster.
  • Such chestnuts completely lose their decorative effect even with a primary lesion. While in private gardens it is possible to fight to save them, in urban landscaping with critical aesthetics, 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 can die in a few years.

Chestnut miner moth (Cameraria ohridella)
Chestnut miner moth (Cameraria ohridella)

What does a chestnut miner moth look like?

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

Regardless of theories of origin and whether the Ohrid miner was imported from East Asia and North America or is natively European, due to the catastrophic climate change, the pests once found only in the south have spread even to 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 miner moth is distinguished by a very decorative variegated pattern on the reddish front wings and black dots on the legs.

One female chestnut miner is capable of laying over 80 eggs. Butterfly eggs are so miniature that it is almost impossible to notice them with the naked eye. They are scattered on the face of the leaf, near the veins.

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

The caterpillars do the greatest harm in the first five phases - from feeding only on plant juice to switching to eating the tissues of chestnut leaves themselves. Only at the age of six do they start spinning and pupation. Pupae of chestnut mining moth do not exceed 0.5 cm in length.

It is the most aggressive of all types of miner moths. For the entire embryonic period, this butterfly is enough from 4 days to 3 weeks. Caterpillar development takes no more than 45 days in the most unfavorable conditions. In one season during the warm months, Ohrid miners can give three offspring. And no other pest destroys the foliage of ornamental trees as quickly as the Ohrid miner.

Horse chestnut struck by the Ohrid miner
Horse chestnut struck by the Ohrid miner

Plants that are affected by the chestnut miner

Despite its name, the chestnut miner moth affects not only chestnuts, and not all horse chestnuts spread equally.

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 fatal for this species of butterflies. So, on horse chestnuts, Chinese, Californian, meat-red, Indian, Assamese, small-flowered caterpillars die in the early stages of development.

Choosing the right species and checking the resistance to Ohrid miner for a particular plant at the time of purchase is the best solution. After all, vulnerable varieties and species have more and more stable competitors every year.

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

  • maiden five-leaf grapes;
  • decorative maples, especially white and holly.
One of the effective methods of creating an unfavorable environment for chestnut miner moths is the installation of "insect hotels"
One of the effective methods of creating an unfavorable environment for chestnut miner moths is the installation of "insect hotels"

Methods for dealing with chestnut miner

In the fight against chestnut miner moths, prevention is the most important means of control and the key to the success of any action. Quickly harvesting and killing the leaves of affected trees is critical. Helps reduce the spread of chestnut miner and trapping belts.

One of the most effective strategies for controlling this species of moth, both globally and in your garden, is the use of biological methods, including fungi and predatory insects, that can control populations of the Ohrid miner.

To create an environment that is as unfavorable to chestnut miner moths, it is better to combine several simple but effective methods:

  1. Attracting songbirds and useful birds to the garden, including tits, starlings and sparrows - hanging feeders and birdhouses.
  2. "Launching" of ladybirds, riders, in particular trichogramma and other beneficial insects.
  3. Installing insect hotels in the garden to attract the natural enemies of the mineral moth.

The main method of combating chestnut miner moths remains the treatment with systemic insecticides of hazard classes 1 and 2. In particular - on the basis of pyrethrum, deltamethrin, diflubenzurol, chitin synthesis inhibitors - systemic insecticides "Insegar", "Lufox", "Confidor", "Aktellik", "Iskra", "Imidacloprid". Or - an alternative to it, but very expensive treatment with special bioinsecticides of narrow specialization of fungal origin. So far, it is available only in some botanical gardens (for example, the drug 'Revive').

When choosing a drug, it is enough to make sure that there are mining moths in the list of types and the manufacturer's recommendations. The methods of using insecticides are limited due to the specifics of the development of the chestnut miner: spraying for this moth that lives in the thickness of the leaf is ineffective, because it is impossible to spray huge crowns evenly and safely.

The only plant protection options are:

  • injections into the trunk;
  • less productive application of insecticides to the soil.

Annual insecticide treatment can only be carried out in May or June (when the temperature rises to 20 degrees) at the beginning of leaf opening. In case of severe damage to chestnuts, insecticides must be combined with systemic fungicides to compensate for the loss of resistance of trees and protect against fungal infections.

Chemical methods of control are associated with considerable risks: it is necessary to assess the effect of systemic pesticides on the ecosystem, and the danger to humans, and the use of the area around the tree, and the effect on neighboring plants and honey insects, in particular bees.

Pheromone traps or spray preparations are also used to control chestnut miner moths, but they are still inaccessible.

Popular by topic