Grapes are susceptible to various bacterial, viral and fungal diseases. In addition, it is damaged by various pests. On average, the annual loss of grape harvest due to disease and pest exposure is about 30%, and with poor or untimely implementation of the necessary protective measures - and more than 40-50%. In this article, we will talk about pests such as ticks.
Grape Felt Tick Mite: General Information
On grape plants, up to 70 different types of ticks can parasitize, but the most common of these is grape itch. It is almost impossible to distinguish with the naked eye. Felt grape tick mite is one of the representatives of eriophoid four-legged ticks. You can meet him almost everywhere where grapes are cultivated. Lives mainly on leaves, less often - on inflorescences.
Morphology
The body of an adult female is worm-shaped cylindrical. Color - milky white or yellowish. Length - 0.17-0.21 mm. The male is slightly smaller - up to 0.14 mm. The pest has a triangular shield with many longitudinal lines. There are several bristles on the back of the flap. On the abdomen there are many rings with microscopic spikes.
Biology
Females hibernate, hiding in the cracks of the bark, under the scales of the kidneys, in fallen leaves. About 1000 ticks can sometimes be immediately located in one kidney. In the spring, when the opening of the eyes begins, they come into activity and migrate. Pests are carried by wind, birds and insects.
During the period of shoot growth, ticks move to open leaves, stick to them from the bottom and begin to actively feed. Substances present in the saliva of a grape pest cause active cell division and deformation of leaf tissues. Under the influence of the enzymes that the itch produces, in the foci of their most active nutrition, concave oval sections appear on the leaves, covered with a white thick felt layer. Accordingly, bulges can be observed on the upper side of the sheet.
During mass reproduction, the grape tick affects a significant part of the leaves on the bush, which change color and become red-brown. Leaf growth is impaired, photosynthesis is reduced, some of them dry up and die out, while the development of the vine bush is generally inhibited. If inflorescences are affected by the pest, the petals become denser, begin to redden and crumble.
If grape itch is not actively fought, then it can lead to a strong decrease in yield. It is better to give preference to grape varieties that are resistant to felt mites.
Gourdotch: control measures
In the event that single tick nests are found on 1 or 2 leaves, they can simply be cut off and carried outside the vineyard. With the defeat of a large number of leaves, a purposeful and active fight against these pests is simply not enough. Do not pick off all affected grape leaves, as this can cause significantly more damage to the bush than mites do.
Inexperienced winegrowers quite often try to fight pests using such a universal remedy as Bordeaux mixture, but the result of such measures is zero, because it is a fungicide that can cope well only with plant diseases.
What to do if there is an itch on the grapes? The control measures in it are as follows:
- After the autumn leaf fall, the head, sleeves and vine of each bush are recommended to be carefully sprayed with 5% lime broth. If this is not done in the autumn, in the spring, before the buds open, the vineyard is sprayed with a 7% emulsion of carbolenium.
- In early spring, before the buds open, spraying with the Dnok solution can give a good result.
- When the shoots reach 5 cm, you can use such a remedy for grape mites as colloidal sulfur.
- In the case of a massive outbreak of the number of ticks (more than 5 individuals on 1 sheet) in the summer, the destruction of pests is carried out by insectoacaricides and acaricides.
- During the growing season, the fight against grape mites can be waged with the help of "Fosfamida", "Fozalona", "Conflict", "Omayta", "Talstar", "Mitaka", "Apollo", "Ortus", etc.
When processing grape leaves, one point should be taken into account. The drug must be applied to the leaves only from below. This is done as follows: the atomizer nozzle is placed at the very surface of the earth and gradually lifted up, processing the inside of the affected leaves. Only in this way can you get to the pest. Conducting processing from above is ineffective. The effectiveness of spraying can be judged by the absence of damage on new leaves. Sometimes it is enough to carry out one treatment, but, as a rule, 2-3 are needed so that the tick on the vine leaves is finally destroyed.
In the traditional literature, organophosphorus pesticides are recommended. However, many grape mites have already developed immunity to this group of chemicals. If you increase the dose, it will adversely affect the plant and the suitability of the crop for food.
A good alternative is Envidor based on spirodiclofen. It is not so toxic to humans and yet quite effective against ticks.
In addition, it is possible to use preparations of the avermectin group, especially when no more than 20-30 days are left before the harvest.
Agrotechnical methods of struggle
When a felt grape mite appeared on the plant, agricultural control measures should also be applied: timely remove scraps of vines and old leaves, clean the branches and sleeves of the old bark.
Spider grape mites
This grape tick is more dangerous than itching, since when it appears, the leaves die off quickly. He settles on the underside of the leaf, pierces his skin and sucks out the juice. First, yellow dots appear in the puncture sites, which, growing, merge into large spots. On the upper side, the leaf turns yellow or brown - depending on the grape variety. When the tick is massively populated in early July, the leaves gradually begin to die, which largely affects the yield.
The spider mite secretes saliva, turning into a thin web. It contains eggs laid by females and young larvae. Pests overwinter under the bark of perennial sleeves of grapes. They begin to lay eggs and eat when the buds open. Spider mites multiply massively and quickly enough. One female can lay up to 100 eggs in 10 days. If the weather is favorable for the pest, it is possible to develop up to 7 or 8 generations during the growing season.
Due to the small size and weight, the tick is able to be carried by the wind. Pest control due to the protective web is very difficult. In addition, the processing of grapes is inconvenient due to the location of ticks on the underside of the leaf.
Spider mite control methods
The methods of control are the same as in the case of the felt mite, but a more frequent frequency of spraying is needed. In addition, it is not recommended to plant decorative flowers near the grape , because spider mites, which will definitely go to the grape bush, often settle on them.
Grape bud mite
It can be found in almost every area of viticulture. Females winter in the eyes at the base of the scales, on the rudimentary leaves of the main and replacement buds. The time of activation and start of tick feeding falls on the period of spring sap flow, when the average daily air temperature is 7-8 degrees Celsius. The appearance of eggs occurs in the first half of May.
Leaf mite
This tick is most commonly found in the southern regions of viticulture. Females winter in the cracks of the bark and under the scales of the kidneys. They are activated at an average air temperature of 7-8 degrees and migrate to young leaves. During the growing season can develop from 5 to 11 generations.