What should be used for spider mites? - briefly
Apply a miticide such as neem oil, insecticidal soap, or horticultural oil, and consider introducing predatory mites (e.g., Phytoseiulus persimilis) for biological control.
What should be used for spider mites? - in detail
Spider mites require a multi‑layered approach that combines chemical, biological, and cultural tactics.
Chemical options include miticides that target the pest’s nervous system, such as abamectin, bifenthrin, or spiromesifen. These products must be applied according to label rates, with attention to resistance‑management intervals of at least 10–14 days between applications of the same mode of action.
Horticultural oils and insecticidal soaps provide contact control. Oil concentrations of 1–2 % (v/v) and soap solutions of 0.5–1 % effectively smother mites and their eggs while preserving beneficial insects when used early in the infestation.
Biological agents offer sustainable suppression. Predatory mites—Phytoseiulus persimilis, Neoseiulus californicus, and Amblyseius swirskii—consume large numbers of spider mites and establish lasting populations if introduced at a ratio of 1–2 predators per 10‑15 pests. Lady beetle larvae (e.g., Rodolia cardinalis) and the predatory thrips (Aeolothrips intermedius) also contribute to control.
Cultural measures reduce mite pressure. Maintain relative humidity above 50 % to disrupt mite reproduction, and avoid excessive nitrogen fertilization that promotes dense foliage. Prune heavily infested leaves, and rotate crops with non‑host species to break the life cycle.
Monitoring is essential for timely intervention. Sticky traps and leaf inspections should be performed weekly; action thresholds typically range from 5–10 mites per leaf segment on the underside of foliage.
Combining these methods—rotating miticides, applying oil or soap sprays, releasing predatory mites, and adjusting environmental conditions—delivers the most reliable suppression of spider mite populations.