How to combat spider mites on begonias? - briefly
Apply neem oil or insecticidal soap to the foliage, repeating every 5‑7 days while maintaining high humidity and removing heavily infested leaves. Isolate the plant and monitor regularly to stop the mite population from spreading.
How to combat spider mites on begonias? - in detail
Spider mites infest begonia foliage by feeding on cell contents, causing stippling, yellowing, and webbing. Early detection relies on inspecting the undersides of leaves with a hand lens; the presence of tiny moving dots confirms an outbreak.
Cultural practices that reduce mite populations include:
- Maintaining humidity above 60 % by misting or using a humidity tray; high moisture deters mite development.
- Avoiding excessive nitrogen fertilization, which produces tender growth favored by the pest.
- Providing adequate air circulation through proper spacing and occasional pruning of crowded stems.
- Removing and destroying heavily infested leaves to interrupt the life cycle.
Mechanical control methods consist of:
- Washing foliage with a strong jet of water to dislodge mites and webs; repeat every 5–7 days until populations decline.
- Applying a solution of mild soap (2–3 % potassium soap) or neem oil (1 % concentration) to both leaf surfaces; ensure thorough coverage and observe a 24‑hour interval before reapplication to prevent phytotoxicity.
Biological agents that target spider mites:
- Introducing predatory mites such as Phytoseiulus persimilis or Neoseiulus californicus; release rates of 10–20 predators per square foot provide effective suppression.
- Employing entomopathogenic fungi (e.g., Beauveria bassiana) as a spray; follow label instructions for dosage and reapplication intervals.
Chemical options, reserved for severe infestations, involve:
- Selecting miticides classified as reduced‑risk (e.g., abamectin, spirotetramat) and applying at the lowest effective rate.
- Rotating active ingredients to avoid resistance development; adhere to pre‑harvest intervals and safety guidelines.
Preventive measures for future protection:
- Quarantining new plants for at least two weeks and inspecting them before introduction to the collection.
- Cleaning tools, pots, and growing media to eliminate residual mite eggs.
- Monitoring environmental conditions regularly and adjusting watering, humidity, and ventilation accordingly.
Integrated pest management combines these strategies, emphasizing early detection, cultural modification, and biological control, while reserving chemical interventions for cases where other measures fail to contain the population.