Symptoms, control and comprehensive treatment of erinosis in grapevines

What is grapevine erinosis?

Grapevine erinosis It is a parasitic disease that primarily affects leaves, although in severe cases it can also affect bunches and buds. This disease is caused by the eriophyid mite. Colomerus vitis (without. Eriophyes vitis), a tiny parasite belonging to the Eriophyidae family.

The mite's life cycle is closely related to the development of the vine, attacking especially during the vegetative period. They are recognized or distinguished three main races of the plague:

Race of false guts: The most common, it generates bulges or vesicles on the leaf surface.
Buds race: It can cause some buds to fail to sprout and significant deformations in new shoots.
Race that curves the leaves: Produces a pronounced bending in the terminal leaves.

These mites are 0,15 to 0,2 mm long, with elongated, pale yellow bodies. The tiny, elliptical eggs are white or yellowish in color and usually require a magnifying glass or microscope to view.

Although it does not always pose a serious threat to production, the disease can result in economic losses and quality if not properly controlled, especially in young plantations or in those plots that show a high incidence after previous seasons.

Biological cycle and factors that favor its development

The life cycle of Colomerus vitis It is adapted to the seasonal development of the vine. During the cold months, the adult mite hibernates in the buds and under the bark of the shoots. With the arrival of spring and the beginning of budding, conditions become favorable, and the mite begins to migrate to the new shoots and leaves, where it feeds and reproduces.

Females lay eggs on the underside of leaves or inside newly formed galls. New generations continue the cycle throughout the season, and several generations can be completed annually (up to seven, depending on the climate and health of the plot).

The factors that favor proliferation of erinosis include:

Excess nitrogen in fertilization, which stimulates tender growth that is susceptible to attack.
High levels of relative humidity and poorly ventilated microclimates, typical of dense or poorly managed vineyards.
Presence of infected plant remains, which serve as a refuge and source of infestation for the following seasons.
Improper watering practices or overwatering contribute to a microclimate conducive to mite development.

These conditions are also ideal for other fungal diseases, such as mildew and powdery mildew, so comprehensive vineyard management is essential.

Symptoms of erinosis in vines

Erinosis manifests itself mainly in young leaves and, in severe cases, can affect bunches and buds. Symptoms include:

Bulges or vesicles on the beam foliar, of variable size, sometimes grouped or arranged irregularly.
Depressions and velvety pubescence on the underside, initially white and turning brown as the disease progresses.
Deformations and curvatures of the terminal leaves, especially in the race that curls the leaves.
Affected buds may fail to sprout, showing a reddish-brown fuzz and a more compact appearance.
In the clusters, especially before flowering, the inflorescences may appear grouped and covered with abundant hairiness.

In severely affected plantations, symptoms may initially be confused with nutritional deficiencies, such as boron deficiency, or with viral infections such as short internode disease.

Early detection of these signs allows action to be taken before the infestation becomes severe, facilitating management and reducing damage.

Damage and consequences of erinosis in grapevines

In most cases, The damage caused by erinosis is usually not serious. in adult vines. However, severe attacks can cause:

Delay and uneven sprouting of the buds, affecting the uniformity of the plant.
Deformed leaves and decreased photosynthetic capacity, which limits the production of reserves and reduces the vigor of the vine.
Reduction in the size and quality of bunches in young plantations or nurseries.
In extreme cases, failure to bud can result in witches' broom-like structures and seriously impair vegetative and reproductive growth.

Although most grape varieties show similar susceptibility, the bud race may present higher incidence in certain sensitive varietiesFor this reason, it is important to pay special attention to the selection of plant material and the health history of the property.

The economic impact of erinosis is mainly associated with the reduction in the quality and quantity of the harvest, and the possible increase in handling costs preventive and curative.

Risk assessment and monitoring

Monitoring for erinosis should focus primarily on plots where an attack has been detected in previous seasons, especially in the bud strain. systematic sampling it implies:

Observe 4 leaves per vine in at least 25 representative vines of the plot.
Calculate the percentage of leaves with symptoms, mainly from leaf emergence to the stage of separated clusters.

Intervention is justified when the The threshold for presence in leaves reaches 5% for the bud raceIf the percentage exceeds 10%, specific treatments or acaricides may be considered, especially if there is a history of severe attacks.

Meteorological stations and phenological records can help anticipate critical moments and adjust management strategies.

Comprehensive Guide to Vine Diseases: Symptoms, Diagnosis, and Comprehensive Treatments

Prevention and cultural measures against erinosis

Prevention is the most effective tool to avoid major damage. Among the cultural and ecological measures recommended ones include:

Removal and burning of pruning remains, to prevent the mite from finding refuge during the winter.
Avoid the use of infected plant material (shoots, buds) for grafting and new plantations.
Control nitrogen fertilization, avoiding excesses that weaken the plant's resistance.
Promote ventilation through appropriate pruning, improving air circulation in the vineyard and making it difficult to establish a microclimate conducive to the pest.
Regular monitoring and manual removal of visibly affected shoots in the initial phase of the attack.

These practices, combined with crop rotation and comprehensive vineyard management, significantly reduce the incidence and severity of erinosis.

Biological management and natural enemies of erinosis

Integrated management should prioritize the conservation and promotion of natural enemies The Colomerus vitis mite is a mite that contributes to the ecological balance of the vineyard and reduces the need for chemical interventions. Among the most effective are:

Predatory mites of the genre Typhlodromus phialatus y Amblyseius, which feed on Colomerus vitis in all its stages of development.
beneficial insects , the Chrysoperla carnea (lacewing) and orius (predatory bugs), as well as certain species of thrips such as Aeolothrips.

Practices that limit the use of non-selective insecticides and promote biodiversity in the vineyard favor the natural biological control of erinosis. For this reason, chemical treatments should always be the last option and restricted to situations of real and sustained threat.

Phytosanitary and chemical treatments

El use of powdered or wettable sulfur It remains the most effective traditional method for controlling erinosis, especially in preventative applications and during the early phenological stages (green tip, leaf emergence, and separated bunches). Sulfur, in addition to its action on the mite, contributes to the prevention of other diseases such as powdery mildew.

In cases where the infestation is very intense or in young plantations/nurseries, approved acaricides for vine cultivation can be considered, always following the manufacturer's specific recommendations and respecting safety deadlines.

It is advisable to alternate the modes of action of pesticides to prevent the development of resistance in the mite population. Treatment is only justified when the percentage of affected leaves exceeds the intervention threshold (usually between 5 and 10%).

The use of chemicals must be sustainable and responsible, always ensuring the balance of the vineyard ecosystem and the safety of the end consumer.

Varietal importance and sensitivity of strains

La Sensitivity to erinosis can vary between grape varieties, although most show a similar response except in the case of the bud race, where certain strains may be more vulnerable. Varieties with natural leaf pubescence or certain structural characteristics may show a lower incidence.

Sensitive varieties They most frequently show severe symptoms, galls and leaf and bunch deformations.
resistant varieties They have natural defenses or leaf structures that are less favorable for mite colonization.

Understanding these differences is essential for integrated management and selection of plant material in new plantations or grafts, thus minimizing the risk of disease development.

Economic evaluation of the impact of erinosis

Erinosis, although in most campaigns it does not justify great alarm, can represent significant economic losses in young vineyards, nurseries, or historically affected plots. These losses can result from:

performance reduction due to a lower number and quality of bunches harvested.
Decline in grape quality, especially in crops intended for the production of high-end wines.
Increase of handling costs, due to the need for phytosanitary treatments, preventive practices and additional labor.

The best economic strategy is the prevention and regular monitoring, preventing the entry and establishment of the mite in the vineyard and thus minimizing the costs associated with its control.

Practical recommendations and handling tips

Frequent inspection of the vineyard to detect the first symptoms in young outbreaks, allowing for early action.
strategic pruning of the affected parts and safe destruction of plant remains.
Responsible management of fertilization and irrigation, avoiding excesses that favor the proliferation of the plague.
Use of phytosanitary products (sulfur, authorized acaricides) only when the infestation levels justify intervention, and always following the technical recommendations to avoid resistance.
Promote biodiversity and natural enemies through ecological practices and good integrated vineyard management.

Grapevine erinosis, although not usually a severe threat, can compromise the health and profitability of vineyards under certain conditions. Early diagnosis, combined with the implementation of preventive measures and the promotion of biological control, will provide the best guarantee for enjoying a healthy and productive crop season after season.