Spider mite on houseplants: how to treat it? - briefly
Control spider mite infestations on indoor foliage by washing leaves with a strong water spray, treating with neem or horticultural oil, and releasing predatory mites such as Phytoseiulus persimilis. Remove heavily infested leaves and maintain high humidity to suppress population growth.
Spider mite on houseplants: how to treat it? - in detail
Spider mites are tiny arachnids that thrive on the undersides of leaves, feeding on plant sap and causing stippling, yellowing, and webbing. Their rapid reproduction makes infestations develop within weeks under warm, dry indoor conditions.
Identification relies on visual inspection. Adult mites measure 0.2–0.5 mm and are often red, yellow, or green. Eggs appear as tiny dots on leaf veins. Webbing is a fine, silvery filament covering leaf surfaces and pot edges.
Factors that encourage growth include low humidity, temperatures above 24 °C (75 °F), and lack of natural predators. Reducing these conditions limits population expansion.
Treatment proceeds in three phases: prevention, removal, and follow‑up.
- Environmental adjustment: Increase ambient humidity to 60 % or higher, mist leaves daily, and avoid placing plants near heating vents. Lower daytime temperatures to 20–22 °C (68–72 °F) when possible.
- Mechanical control: Rinse plants with a strong stream of lukewarm water, focusing on leaf undersides. Use a soft brush or cotton swab dipped in soapy water (½ tsp mild liquid soap per litre) to dislodge mites.
- Chemical options: Apply horticultural oil (e.g., neem or mineral oil) at the label‑recommended rate, covering all foliage. If oil proves insufficient, use a miticide containing abamectin or spinosad, observing a 7‑day interval between applications. Rotate products to prevent resistance.
- Biological agents: Introduce predatory insects such as Phytoseiulus persimilis or Amblyseius cucumeris. Release according to supplier instructions, ensuring the plant environment remains suitable for the predators (moderate humidity, no broad‑spectrum insecticides).
After each treatment, inspect plants every 3–5 days. Continue the chosen control method until no mites or eggs are visible for two consecutive inspections. Dispose of heavily infested foliage by sealing it in a plastic bag and discarding it to avoid reintroduction.
Maintain a regular care schedule: weekly leaf cleaning, balanced fertilization, and periodic humidity checks. Consistent monitoring and prompt action keep spider mite populations below damaging levels.