How can spider mites be treated on cucumbers in a greenhouse? - briefly
Apply miticides such as abamectin or spirodiclofen, and integrate biological agents like Phytoseiulus plicatus or Neoseiulus californicus. Combine these treatments with strict sanitation, removal of heavily infested foliage, and optimal humidity control to suppress spider‑mite populations.
How can spider mites be treated on cucumbers in a greenhouse? - in detail
Spider mite infestations on cucumber crops in greenhouse production require a systematic approach that combines prevention, monitoring, and control measures.
Regular scouting should begin at planting and continue weekly. Inspect the undersides of leaves with a hand lens; early colonies appear as tiny moving specks. When populations exceed 5 mites per leaf, initiate treatment.
Cultural tactics reduce mite development. Maintain relative humidity above 60 % by misting or using humidifiers; high humidity disrupts mite reproduction. Keep temperatures between 18 °C and 24 °C, avoiding prolonged periods above 30 °C, which accelerate life cycles. Remove plant debris and replace heavily infested foliage to eliminate shelters.
Biological agents provide effective, residue‑free control. Release predatory mites such as Phytoseiulus persimilis or Neoseiulus californicus at a rate of 5–10 predators per square meter. Ensure adequate humidity and avoid broad‑spectrum insecticides that would harm these natural enemies. Supplement with predatory insects like Amblyseius swirskii for broader pest coverage.
Chemical options serve as a last resort when mite numbers threaten yield. Apply horticultural oil at 1–2 % concentration, covering both leaf surfaces to suffocate mites. Use insecticidal soap (2–5 % fatty acid solution) for rapid knock‑down; repeat after seven days if necessary. Select acaricides with low mammalian toxicity, such as abamectin or spirotetramat, and rotate modes of action according to label recommendations to prevent resistance.
Integrate all measures into an IPM program: start with cultural sanitation, maintain optimal microclimate, augment with predatory releases, and reserve oil‑based or selective acaricide applications for confirmed outbreaks. Record mite counts, treatment dates, and environmental conditions to refine thresholds and improve future management decisions.