What to do if spider mite infestation occurs? - briefly
Remove and destroy heavily infested foliage, then treat remaining plants with a miticide or insecticidal soap while increasing humidity and regularly washing leaves. Repeat applications every 5–7 days until the mites are eliminated.
What to do if spider mite infestation occurs? - in detail
A spider mite outbreak begins with the appearance of tiny speckled patches on leaf surfaces, often accompanied by a fine webbing. Early detection relies on inspecting the undersides of foliage with a magnifying lens; the insects are less than 1 mm long and move quickly when disturbed.
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Isolation – Remove affected plants from the surrounding collection. Place them on a separate bench or in a quarantine cage to prevent migration to healthy specimens.
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Physical removal – Rinse leaves with a strong jet of water to dislodge mites and eggs. For delicate plants, use a soft brush or a cotton swab dipped in lukewarm water. Repeat the rinse every 2–3 days for two weeks.
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Cultural adjustments – Lower ambient humidity to below 50 % and increase air circulation with fans. Reduce nitrogen fertilization, which encourages rapid leaf growth and creates a favorable environment for the pest. Maintain temperature within the optimal range for the host plant, avoiding extremes that stress foliage.
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Biological agents – Introduce predatory mites such as Phytoseiulus persimilis or Neoseiulus californicus. Release rates of 10–20 predators per square foot are effective; monitor predator establishment weekly. Supplemental releases may be necessary if mite populations rebound.
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Botanical oils – Apply horticultural oil or neem oil at a concentration of 1–2 % v/v, thoroughly covering leaf undersides. Spray in the early morning or late evening to minimize phototoxicity. Reapply every 5–7 days until no moving mites are observed.
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Chemical controls – When biological and cultural measures prove insufficient, use a miticide registered for the specific crop, such as abamectin or spirodiclofen. Follow label‑specified dosage, limit applications to three per season, and rotate with a different mode of action to delay resistance.
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Monitoring – Install sticky traps on the plant canopy to gauge adult mite activity. Conduct weekly counts of live mites per leaf; a decline below five per leaf indicates successful suppression.
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Prevention – Quarantine all new acquisitions for at least two weeks, inspecting them under magnification before integration. Maintain a regular schedule of leaf‑surface cleaning and occasional releases of predatory mites as a preventive measure.
By combining isolation, mechanical cleaning, environmental management, biological agents, targeted oil treatments, and, if required, selective miticides, the infestation can be eliminated while preserving plant health. Continuous monitoring ensures early detection of any resurgence, allowing rapid corrective action.