What is the virus of the micro mite of the vine?
The micro vine mite virus, like many other pests or diseases, gets its name from the first plant where it was found. In this case this virus caused great losses in the wine and vineyard industry.
The virus comes from the bite and fluid exchange of the Calepitrimerus vitis micro mite, an eriophid mite of about 0.2mm and yellowish in color. Its eggs are round and pale in color and usually measure about 0.04mm. As you can see, the size of these individuals makes it impossible to detect them with the naked eye.
It can happen that this infection disappears and reappears in our crops, since the females of this mite spend the winter under the scales of the buds on thumbs and arms. During the year there are several generations that cause an increase in symptoms and a subsequent reduction.
What damage does the micro vine mite virus cause?
The most frequent damages and symptoms appear in the most tender shoots, in tips and growth buds. The new shoots will grow much slower than normal, the leaves will twist with bulges, very marked nerves and very short internodes.
In bloom, they will reduce flower production and resin production. In extreme infections there will be no resin production, leaving the flowers as artificial and plastic.
As with other diseases or pests, if we have vigorous growth and we can make the development of the plant faster than the growth of the pest, we can get to harvest, although the production losses will be apparent.
Often we will observe that as the leaves grow, the symptoms will disappear in the large leaves already formed, but that is because the pest is in the growth buds and it is continuously moving to new shoots when they become harder. This pest prefers young shoots.
It should also be said that this mite has a select palate and a preference for some varieties or others. We were able to see how it clearly affected one variety and did not affect those around it until this individual was eliminated, then they decided to move to another variety.
How is the vine micro mite virus infection spread?
Unlike most viruses that can be transmitted through tools, it appears that in this case the infection is caused and clearly spread by the micro mite Calepitrimerus vitis. If we eradicate the plague, we will end the symptoms of the infection. That means cleaning up all the remains of dead leaves or stems that may be in the vicinity.
How do you fight the Micro Vine Mite Virus?
Considering that they hibernate behind the skin of the branches, it is very difficult to act on this pest when it is in hibernation. The key moment will be when it begins to affect the buds, but without waiting for it to be too late. At this time the micro mites will move from the nodes and branches to the buds, so whenever we apply a treatment we must do it thoroughly and spraying not only the underside of the leaves but also the knots of all the branches and the path from the knots to them.
Whenever the size allows it, the best option is to do a dive to make sure that we get the treatment everywhere. Still, this mite tends to laugh at most products for home gardening, and the sale of strong chemicals is restricted to people who have a phytosanitary card, for which you must take a course.
Very often for the vineyard, Sulfur or Spirodiclofen is used to combat it.
Biological control looks for natural predators for this type of mite that have very little impact on our crops. Normally, the use of predators does not completely exterminate the pest, but it will keep it in a balance that will allow us to harvest with more or less result. There are several predators among which we can highlight the phytoseids Typhlodromus pyri, Typhlodromus phialatus or Kampinodromus aberrans.
At the domestic level this is clearly the best option and the most respectful with the environment.
Whether we use chemical control or biological control, if it is a mother plant, we will reduce the growth buds to one, since this way we will better locate the treatment and it will be more effective.
-To quarantine all new acquisitions in our mothers wardrobe, especially if we do not know where they came from.
-Eliminate infected varieties that we have not been able to recover and all the remains of these.
-Maintain the culture free of micro mites to avoid contagion from other individuals.
-Keep the vines, or vine branches, away from our crops.
-Never wear shoes or clothing that has been brought near a vineyard or vine branch.