Spider mite on grapes

A spider mite is one of the most common insects capable of dooming a plant to death. It settles on a leaf and sucks out all the juices from it, as a result the plant dies. Horticulturists constantly make sure to detect uninvited guests in time and protect useful plantings.

Description of the pest

A spider mite is a small invertebrate, arthropod, spider-like insect. About 70 species are known to man and all of them feed on plant juice.

The appearance of ticks: the body is oval, brown, red or yellow-green in color, 3-7 mm long. The small head has a proboscis with which the insect pierces the fabric of the leaf, feeds, and at the same time secretes a liquid containing substances that harm the leaf. As a result, the processes occurring in the leaf plates begin to slow down or stop altogether. The leaves are unable to fully synthesize organic substances, and the plant slowly dies.

In addition, mites form webs - threads, under which you can see entire colonies of insects that feed on the juice, poisoning the leaves with their "saliva".

The female mite spends the winter under the exfoliated bark of grapes, crawling into cracks and other warm places. They often settle somewhere near the vine - in fallen leaves, uprooted or growing weeds, or in compost piles.

With the arrival of spring, when the air temperature rises above +13, they wake up and immediately begin to restore the resources spent during the winter - to suck juice from fresh leaves. At the same time, eggs are laid, from which new individuals will appear after 10-15 days.

During the season, one female can lay up to 100 eggs and produce 10-15 generations of offspring. Ideal conditions for the spread of the spider mite are +25-35, humidity 50-70%. In dry and hot weather, ticks multiply even faster.

Damage

Breeders have not yet created grape varieties that could independently resist ticks. Most likely, for this they will have to create a genetically modified organism with an artificially changed genotype. After all, there are varieties of potatoes that are resistant to the Colorado potato beetle. But it will be the same GMO that consumers are so afraid of.

Basically, grapes react to the appearance of mites with yellowing or reddening of the leaves - these features depend on the variety. First, red, silver, yellow spots appear on the upper part of the leaf plate. The inside of the leaves turns white. Then a brown coating appears, the leaves curl, dry and fall.

Without healthy, full-fledged leaves, serious biochemical and physiological changes occur in the plant. The amount of carbohydrates, yellow pigments and chlorophyll is significantly reduced. Breathing and metabolism become difficult, enzyme activity slows down, and the amount of nitrogen decreases.

The plant, deprived of the opportunity to eat and breathe normally, begins to get sick - the growth of new shoots and leaves slows down, the fruits are not able to fully ripen and gain the necessary amount of useful substances. The yield decreases by a third, the amount of sugar decreases to 5 mg per 100 cubic centimeters. Despite all the vine's efforts, without human help it dies in 3-4 years.

Methods of treatment

Gardeners and viticulturists talk about two main directions of protection - agrotechnical and chemical. Agrotechnical measures mean the removal of weeds growing next to the vine, removal and burning of dry leaves, organic residues. It is necessary to remove from the site piles of firewood, piles of junk, in which ticks could safely overwinter. It is advisable to dig up the ground around the grapes in autumn so that insects and their larvae die during frosts.

Mites do not like moisture, so the vine should be sprayed more often with a hose, directing the stream of water to both sides of the leaf - in the conditions of a hot southern summer, it will not harm them. The main thing is to carry out procedures early in the morning or in the evening after sunset to prevent sunburn.

Chemical measures include treatment with special drugs. As prevention, you can use such drugs as Nitrofen and Envidor - they are less toxic to the plant, and at the same time they destroy pests quite effectively.

The first spraying is carried out in the spring, when the buds are just beginning to open. Then treatment with acaricidal drugs is carried out every two weeks. At the same time, it is important that the liquid falls on the leaves from all sides, since the insect colonies are located in the lower part.

The vines are sprayed with DNOK-2 twice a year - in the spring before the leaves bloom and in the fall after the harvest and the leaves have fallen. This tool rids grapes of spider mites and other insects.

If the plant is severely affected by a mite, more effective acaricidal drugs are used, such as Amitraz, Demitay, Omayt and others. They are more dangerous for insects, and at the same time toxic for fruits. Therefore, it is better to carry out preventive treatments, so that later there is no need to use products that have a negative effect on the vine and bunches.

Colloidal sulfur is among the drugs that are harmless to the plant, but its effectiveness is manifested only at temperatures above +

15 degrees. In addition, it does not damage the mite eggs, from which the colony can be reborn again.

Emulsion of anthracene oil is another effective means against ticks, it can be bought in a specialized store and sprayed in early spring.

Biological means of protection against the spider mite

Another effective means of combating the spider mite on grapes is the combination of agrotechnical methods with biological preparations. At the first signs of spider mite infestation, treat with the biological insectoacaricide Imexab™ in a dosage of 10g/10l. The composition of the drug includes avermectins and emamectins - these are biologically active substances obtained during the vital activity of the fungus Streptomyces Avermitilis. The principle of action of Imexab™ is contact-intestinal, already 8 hours after treatment, pests are paralyzed and stop feeding, 2-3 days after treatment, complete death occurs.

Imexab™ also has an ovicidal effect, which allows you to completely destroy tick colonies, including eggs. Thanks to biological components, grapes can be consumed 48 hours after processing.

The result of Imexab™ treatment on whitefly egg-laying

(brown eggs, these are destroyed eggs already 12 hours after processing)

It must be remembered that the tick knows how to defend itself, its protection is a strong web made of a web, so one treatment may not be enough, the procedure will have to be repeated once more. It is also recommended to add Izomax™ 2ml/10l adjuvant to the tank solution when treating spider mites, thanks to its work, grapes are evenly covered with the working solution and allow to get into the most difficult places and penetrate through the dense webs woven by mites. It is especially relevant to use Izomax™ to treat the underside of leaves where pest colonies are located.

The work of Izomax™ on grape leaves

Please note that insects develop immunity against any chemical agent. Therefore, it is better to use different drugs made from different active substances. Biological products do not cause resistance in pests, so they can be used throughout the season.