How to treat spider mites on strawberries in autumn? - briefly
Apply an approved miticide—such as neem oil, spirodiclofen, or a sulfur‑based product—early in the autumn, followed by weekly sprays to suppress the population, and remove heavily infested leaves. Maintain good air circulation and avoid overhead watering to reduce humidity that favors mite development.
How to treat spider mites on strawberries in autumn? - in detail
Spider mite populations increase as temperatures drop and humidity rises in the late growing season, making strawberry plants especially vulnerable. Damage appears as stippled leaves, fine webbing, and reduced fruit quality, which can lead to significant yield loss if left unchecked.
Effective management begins with regular scouting. Examine the undersides of leaves every 3–5 days, looking for tiny moving dots and silken threads. Use a hand lens to confirm identification and estimate infestation levels: light (≤5 mites per leaf), moderate (5–20), or heavy (>20). Record findings to guide intervention thresholds.
Cultural measures reduce habitat suitability. Remove plant debris and fallen fruit to eliminate shelter. Thin dense foliage to improve air flow, lowering leaf temperature and humidity. Water plants early in the day with a fine spray to wash mites off leaves; avoid overhead irrigation late in the day, which creates a moist environment favorable to reproduction.
Biological agents provide targeted suppression. Release predatory mites such as Phytoseiulus persimilis or Neoseiulus californicus at a rate of 10 k predators per m² when moderate pressure is detected. Maintain a pollen source (e.g., buckwheat) to sustain predator populations. Apply entomopathogenic fungi (e.g., Beauveria bassiana) according to label instructions for additional control, especially under cooler, damp conditions.
Chemical options are reserved for severe outbreaks. Select acaricides with low residual activity to protect beneficial insects: sulfur (2 % wettable powder), spirodiclofen (0.5 % soluble concentrate), or abamectin (0.025 % concentrate). Rotate active ingredients every 7 days to prevent resistance. Apply at the recommended dosage, covering both leaf surfaces, and repeat after 5–7 days if mite numbers remain above threshold.
After treatment, clean equipment and discard heavily infested plant material. Store mulch away from the field to avoid re‑introduction. Implement a preventive schedule that includes early‑season scouting, predator releases, and periodic sulfur applications to keep populations below damaging levels throughout the autumn harvest period.