What should be sprayed on cucumbers to control spider mites? - briefly
Apply a horticultural oil (e.g., neem oil) or a certified insecticidal soap thoroughly to cucumber leaves, especially the undersides, to smother spider mites. For heavy infestations, a low‑toxicity pyrethrin spray can be used according to label instructions.
What should be sprayed on cucumbers to control spider mites? - in detail
Effective control of spider mites on cucumber plants requires a spray that targets the pest while preserving the crop and beneficial insects. The most reliable options include:
- Horticultural oil – mineral or plant‑derived oil applied at 1–2 % concentration. Covers mites and their eggs, causing desiccation. Apply early in the morning or late afternoon to avoid leaf burn.
- Neem seed extract – 2 % emulsifiable concentrate mixed with water. Acts as an antifeedant and disrupts mite reproduction. Re‑apply every 7–10 days during active infestations.
- Insecticidal soap – 2–5 % potassium salts of fatty acids. Kills motile stages on contact. Use a fine spray to ensure leaf coverage; repeat after rain or when new colonies appear.
- Spinosad – 0.5–1 % formulation, systemic and contact action. Effective against mobile stages and early eggs. Observe pre‑harvest interval (usually 7 days) and rotate with other modes to prevent resistance.
- Abamectin – 0.1 % solution, selective for mites. Provides rapid knock‑down of adult and immature stages. Follow label restrictions on frequency (max. 2 applications per season).
Biological alternatives complement chemical sprays:
- Predatory mites (Phytoseiulus persimilis, Neoseiulus californicus) – released at 50–100 mites per plant. Establishes a self‑sustaining population that suppresses spider mite colonies.
- Entomopathogenic fungi (Beauveria bassiana) – applied as a wettable powder at 1 g L⁻¹. Infects mites on contact, especially in humid conditions.
Cultural practices enhance spray efficacy:
- Maintain canopy airflow by pruning excess foliage; reduced humidity discourages mite reproduction.
- Monitor plants weekly with a 10× hand lens; early detection allows low‑dose interventions.
- Avoid broad‑spectrum insecticides that eliminate natural enemies; reserve them for severe outbreaks only.
When mixing sprays, use clean water at 20–25 °C, add a non‑ionic surfactant (0.1 % v/v) to improve leaf wetting, and calibrate sprayers to deliver 200–300 mL m⁻². Record application dates, product names, and concentrations to track resistance development and comply with residue regulations.