How can spider mites be removed in a greenhouse? - briefly
Introduce predatory mites (e.g., Phytoseiulus persimilis) and apply horticultural or neem oil to suppress spider‑mite populations; maintain low humidity and conduct frequent plant inspections. Combine these actions with thorough sanitation of the greenhouse to prevent reinfestation.
How can spider mites be removed in a greenhouse? - in detail
Spider mites constitute a primary threat to greenhouse crops, feeding on plant sap and causing stippling, bronzing, and reduced vigor. Rapid population growth under warm, dry conditions demands prompt intervention.
Cultural measures reduce infestation risk.
- Remove plant debris and weeds that shelter mites.
- Maintain humidity above 60 % when feasible, as moist environments suppress mite development.
- Regulate temperature to avoid prolonged periods above 28 °C, which accelerate life cycles.
- Rotate crops and use resistant varieties where available.
- Implement regular scouting, inspecting the undersides of leaves with a hand lens at least twice weekly.
Biological agents provide sustainable control.
- Introduce predatory mites such as Phytoseiulus persimilis for fast‑reproducing spider mite species; release rates of 10–20 predators per square meter are effective.
- Deploy generalist predators like Neoseiulus californicus and Amblyseius swirskii to cover a broader pest spectrum.
- Apply entomopathogenic fungi (e.g., Beauveria bassiana) as a spray; ensure leaf surface remains wet for 24 hours to facilitate infection.
Chemical options serve as a backup when populations exceed economic thresholds.
- Select miticides with differing modes of action to prevent resistance; rotate products according to label‑provided resistance‑management guidelines.
- Use contact acaricides (e.g., abamectin) for immediate knock‑down, followed by systemic options (e.g., bifenazate) for residual activity.
- Adhere to recommended dosages, pre‑harvest intervals, and safety precautions to minimize phytotoxicity and residue concerns.
An integrated pest‑management program combines these tactics. Establish a threshold of 5–10 mites per leaf before initiating treatment. Record all interventions, monitor efficacy, and adjust strategies based on population dynamics. Continuous documentation ensures long‑term suppression while preserving beneficial organisms and crop quality.