Prévention et Méthodes de Lutte

Spider mites are one of the main pests in apple orchards. Their presence can cause significant losses in terms of fruit quality and yield. In this article, we will discuss the symptoms of their infestation, available prevention methods, and control methods in organic and conventional farming.


Symptoms of a Dust Mite Infestation

Visible Effects on Leaves

  • Discoloration: Leaves change from bright green to pale yellow, then take on a grayish tint.
  • Bronzed or leaden appearance: A significant infestation gives the leaves an abnormal color, a sign of stress.
  • Presence of fine webs: Mite webs often appear between twigs and on the underside of leaves.
  • Early defoliation: In case of severe attack, the leaves fall before the end of the season.

Impact on Fruits

Fruits produced by infested trees are often smaller, of lower quality, and have reduced commercial value.


Mite Species Affecting Apple Trees

Red Apple Mite ( Panonychus ulmi )

  • Damage: Discoloration and premature leaf drop.
  • Life cycle: Eggs spend the winter on branches, ready to hatch in spring.

Two-spotted mite ( Tetranychus urticae )

  • Damage: Appearance of fine webs and drying of leaves.
  • Favorable conditions: Hot, dry temperatures favor their proliferation.

Tiger Pear ( Stephanitis pyri )

  • Specific damage: Bites on leaves causing deformations and reduced photosynthesis.
  • Special feature: This mite can take refuge in trap strips intended for other pests.

Prevention of Mites in Orchards

Encourage Biodiversity

  • Install flower strips to attract ladybugs and lacewings.
  • Encourage the planting of diverse hedges to accommodate beneficial insects, such as Typhlodromus pyri .

Adopt Good Cultural Management

  • Reasonable Fertilization: Limit excessive nitrogen inputs, which promote the growth of young shoots that are particularly attractive to mites.
  • Moderate Pruning: Practice balanced pruning to avoid overly dense and vulnerable vegetation.
  • Controlled Irrigation: Avoid excessive watering, which creates a microclimate favorable to mites.

Working the Soil

Light tillage at regular intervals can disrupt the life cycle of mites and reduce their populations.


Methods of Mite Control

Biological Control

Predatory Mites

  • Species like Typhlodromus pyri play a key role in regulating pest mite populations.
  • Augmentative introduction: In organic orchards, these auxiliaries can be introduced to restore the natural balance.

Use of Sulfur

  • Effective in organic farming, sulfur disrupts the metabolism of mites while respecting natural predators.
  • Application Tips: Apply in cool weather to avoid the risk of leaf burn.

Clay-Based Physical Barrier

Clay sprayed onto the foliage creates a protective layer that prevents mites from attacking.

Conventional Fighting

Chemical Acaricides

  • Kanemite (acequinocyl): Effective against mobile stages of mites.
  • Acramite (bifenazate): Recommended for resistant populations.
  • Nealta (cyflumetofen): Specific to mites, with low impact on other insects.

Best Practices

  • Treat only infested areas to protect beneficials elsewhere in the orchard.
  • Alternate active ingredients to avoid the development of resistance.
  • Stop treatments before the end of summer to allow auxiliary populations to rebuild before winter.

Monitoring and Assessment of Mite Populations

Trapping and Observation

  • Place sticky traps to detect the first signs of presence.
  • Inspect leaves regularly, especially during hot, dry periods.

Intervention Thresholds

A low level of infestation can be tolerated thanks to the action of auxiliaries. Intervention is necessary if economic tolerance thresholds are exceeded.


Economic and Ecological Impact

  • Yield Loss: Severe infestations weaken trees, reducing both the quantity and quality of fruit harvested.
  • Environmental Impact: Excessive use of acaricides disrupts the ecosystem by also eliminating natural predators.

Importance of Integrated Pest Management: By combining biological methods, cultural practices and targeted treatments, it is possible to manage mites in a sustainable and effective manner.


A Solution for Your Orchards with Arboriverse

If your fruit trees have been severely affected by a mite infestation, it's essential to find robust, suitable plants to replace the damaged ones. Arboriverse, a wholesale supplier specializing in fruit trees, offers solutions tailored to your needs.

Why Choose Arboriverse?

  • Wide Range of Apple Trees: Available in high stem, half stem, cattail and bare root.
  • Professional Quality: Trees produced in specialized nurseries to guarantee optimal yield.
  • Direct Producer Prices: An economical solution to boost your crops.
  • Fast and Reliable Delivery: Directly to your plot, anywhere in France.

Personalized Technical Support

  • Design your orchard with varieties suited to your region and your constraints.
  • Take advantage of technical advice to maximize plant recovery and productivity.

Take Advantage of Our Benefits

  • Online ordering made easy.
  • Free quote with quick response within 48 hours.
  • Careful delivery within 15 days.

FAQs

  • How can you recognize a mite infestation? Look for discolored leaves, fine webbing, and premature leaf drop.
  • Which mites are most harmful to apple trees? The red mite ( Panonychus ulmi ) and the pear tiger mite ( Stephanitis pyri ) cause the most serious damage.
  • Is sulfur safe for beneficials? Yes, when applied correctly, it has a low impact on natural predators.
  • When should you take action against dust mites? Only when economic thresholds are exceeded, favoring biological solutions.
  • How important are natural predators? They regulate mite populations and reduce the need for chemical interventions.

Conclusion

Apple tree mites pose a significant challenge for orchardists. With an integrated approach combining prevention, biological control, and rational management of chemical treatments, it's possible to minimize their impact while preserving the ecosystem. Arboriverse is here to help you revive your orchard with high-quality fruit plants and expert advice. Contact us today to turn this challenge into an opportunity.