The felt mite is a dangerous pest of grapes

Grape mite (aka felt mite, phytoptus, eryophis) is a representative of a large family of gall mites, many of which are serious pests of cultivated plants (for example, the bud currant mite and pear gall mite are well known to many).

The felt mite is monophagous, that is, it damages exclusively the grapevine, not being "interested" in other crops. The size of the mite is only 0.1-0.2 mm, but the damage from it is enough - a widespread pest absolutely throughout the viticulture zone, where it actively damages the leaves and buds (and sometimes the bunches) of the plant, disrupting the normal process of photosynthesis and the formation of flowers and berries. as a result, the quantity and quality of the crop suffers greatly.

Symptoms of damage by a felt mite

You will not see the pest itself on the vine - we have already mentioned that it is very small. You can detect only traces of its vital activity - depressed spots on the underside of grape leaves, covered with a light fluffy coating (on the outside of the leaves, accordingly, swelling-bulges are visible). Then the plaque darkens to red-brown, and the leaves become as if covered with felt. With a strong development of the disease, "felt" spots grow and merge, leaves wither, dry and fall prematurely, damaged buds do not open, bunches dry up.

Why does this happen?

Adult mites usually overwinter directly on the plant, under the covering scales of the buds or in the cracks of the bark. In the spring, when the air temperature rises to about 15 °C, they go outside and move to the lower part of young leaves, pierce their skin and begin to suck the juice. At the puncture site, in the depression, a fluff is formed, red in red varieties and yellow-brown in white, which corresponds to a bulge (gal) on the upper side of the leaf. This fuzz is pathologically elongated hair-like cells of the epidermis of the plant, which are formed due to irritation with the saliva of arachnids, so it cannot be easily wiped off with the fingers, like, for example, plaque in powdery mildew.

The first galls usually appear on grape leaves already in May, they feed and lay eggs in the "felt" mites, and with the increase of colonies and gradual drying, the galls migrate further to young leaves that have just blossomed.

The process of resettlement on young apical leaves takes place throughout the summer, and by autumn the pests are completely settled on the periphery of the grape bush. During the warm season, several generations of the felt mite develop.

Grape varieties with weak pubescence of delicate leaves are more affected by the pest than others, while grapes with dense and/or hard pubescence of leaf plates are much less likely to be attacked by the mite.

Active development and rapid spread of the mite in the area is facilitated by hot, dry weather. The mite can also be transferred from plant to plant with the help of the wind, with non-disinfected garden tools or from infected planting material brought to the site.

How to effectively deal with the felt mite?

Measures to combat the felt mite include agrotechnical measures and treatment with chemical preparations.

If there are single affected leaves and buds, they should be cut off and burned.

In the case when the mite is already actively developing and signs of damage are noted on many plants, preparations containing sulfur (Tiovit Jet, colloidal sulfur), as well as specialized acaricides or insectoacaricides (Aktara, Fufanon-Nova, Aliot, Diflomite) can help.

Treatment with sulfur-containing drugs is carried out twice with an interval of about 10 days - either the drug is used according to the instructions or fumigation with sulfur vapors (be very careful, the temperature and humidity of the air have a great influence on the activity of sulfur).

Treatment with acaricides is carried out according to the instructions - it is usually necessary to dilute the drug in water and thoroughly spray the crown with a solution, paying special attention to the fact that the leaves are wetted on both sides. Such processing is better to be carried out in the morning or evening, in windless weather.

In some recommendations, you can read the proposal to treat plants against the grape mite at one or another stage of infection with the drugs Vertimek, BI-58, Aktellik, Omayt, Karate Zeon, Ortus, Talstar - keep in mind that all of them are prohibited for use in personal farms !

That is why, if you do not want to use chemicals, we advise you to use the biological insecticide Imexab™, in a dosage of 10 g/10 l. Thanks to the natural active substance avermectin and emamectin, it actively destroys the tick. As it was written above, the leaves should be covered with the working solution completely and from both sides, that is why the adjuvant Izomax™ 2ml/10l is added to the tank solution. Thanks to this, the grape leaves will be covered evenly and the working solution will reach even the most difficult places.

Can preventive measures be used to reduce the likelihood of grapevine itch infection or to stop its spread? You can.

First of all, in autumn, you should carefully clean the trunk circles from precipitation (especially when there were cases of diseases during the season) and deprive the area plant remains that are burned outside its boundaries.

• Dig up the soil in the vineyard both in the spring before the buds open, and in the fall after the leaves fall.
• Do not allow the shoots of the vine to lie on the ground - they must all be tied to the wallpaper.
• For prevention, after the fall of the leaves in autumn or in early spring after the snowfall, treat the bushes with a 5% solution of lime or lime-sulphur decoction.
• During sanitary and formative pruning of the vine, pay attention to its condition - be sure to remove damaged shoots and clean the bark with signs of damage.

The fight against the grape mite is not a quick and time-consuming task. Therefore, in order not to have to carefully "fight" with a miniature pest season after season, one should first of all follow the agricultural techniques of growing vines and limit oneself to preventive measures, trying to avoid serious infection, when strong "chemistry" has to be applied.