Conditions That Trigger an Outbreak
Optimal reproduction occurs at 28–32°C and humidity below 50%. Above 70% humidity, reproduction slows; above 80% it nearly stops.
The first response to a mite detection — not an acaricide, but raising humidity to 65–70% and lowering temperature.
Diagnosis
Early signs: small pale or yellowish stippling on the upper leaf surface, evenly scattered with no defined margin. On the underside — live mites visible at 10× magnification.
Identify before webbing appears: webbing indicates a heavy infestation.
Control
Step 1 — Microclimate: raise humidity to 65–70%.
Step 2 — Biological control:
- Phytoseiulus persimilis — effective at 20–25°C and humidity above 60%
- Neoseiulus californicus — broader temperature tolerance
Step 3 — Acaricide: when active feeding is visible on 5–10% of plants. Mandatory rotation of IRAC mode-of-action groups.
Three Critical Mistakes
- Repeating the same product when efficacy declines
- Relying on chemistry alone without correcting the microclimate
- Failing to introduce predatory mites after a chemical knockdown
Signs of Successful Control
- Active feeding signs present on fewer than 5% of plants
- Mobile predatory mites present in the crop
- Humidity stable at 65% or above