Fitover does not work against spider mites, what should be done?

Fitover does not work against spider mites, what should be done? - briefly

Use a miticide specifically registered for spider mites—options include abamectin, bifenazate, or spirodiclofen—and combine treatment with cultural practices such as removing infested foliage and maintaining low humidity. Rotate chemicals with different modes of action to prevent resistance.

Fitover does not work against spider mites, what should be done? - in detail

When a horticultural oil such as Fitover fails to suppress spider mite populations, the first step is to confirm that the product was applied according to label instructions: correct dilution, thorough coverage, and appropriate timing relative to pest life stage. Inadequate coverage or excessive rain soon after treatment can render the oil ineffective.

Identify the underlying cause of failure:

• Resistance or tolerance: Repeated use of the same oil can select for mite strains with thicker cuticles or behavioral avoidance.
• Environmental conditions: High temperatures (>30 °C) can cause rapid evaporation of the oil, reducing contact time.
• Application errors: Insufficient spray volume, poor nozzle selection, or failure to treat the undersides of leaves where mites congregate.

Once the cause is pinpointed, implement an integrated approach:

1. Cultural controls

   • Reduce plant stress by optimizing irrigation and fertilization; stressed plants attract more mites.
   • Prune heavily infested foliage and destroy it to lower the initial population.
   • Increase air circulation through proper spacing and staking to discourage mite proliferation.

2. Biological agents

   • Release predatory mites (e.g., Phytoseiulus persimilis, Neoseiulus californicus) at a rate of 10–20 predators per square meter.
   • Apply entomopathogenic fungi such as Beauveria bassiana according to manufacturer recommendations; these fungi penetrate mite cuticles and reproduce within the host.

3. Chemical alternatives

   • Use miticides with a different mode of action, such as abamectin, spirodiclofen, or bifenthrin, rotating chemicals to prevent resistance buildup.
   • Follow resistance management guidelines: limit each miticide class to no more than three applications per season and allow a minimum interval of 14 days between treatments.

4. Monitoring and thresholds

   • Conduct weekly leaf inspections using a hand lens; count mites on ten random leaf sections.
   • Apply treatment only when counts exceed the economic threshold (typically 5–10 mites per leaf section for high‑value crops).

By combining accurate diagnosis, cultural sanitation, biological augmentation, and judicious chemical rotation, growers can restore effective control of spider mites after an oil product proves insufficient. Continuous monitoring ensures rapid response and minimizes the risk of future treatment failures.