When does the second wave of mites occur? - briefly
The second infestation of mites generally emerges in late summer, around August – September, when temperatures stay high and humidity increases. It follows the initial spring outbreak as the crop’s growth stage provides abundant feeding sites.
When does the second wave of mites occur? - in detail
The second surge of mite activity typically appears in late summer, often between July and September, depending on regional climate and host plant cycles. Temperature thresholds of 25 °C to 30 °C and relative humidity above 60 % create optimal conditions for rapid population growth. At this stage, adult females increase egg production, leading to exponential expansion of the colony.
Key factors influencing the timing include:
- Photoperiod: Lengthening days trigger developmental acceleration in many mite species.
- Host plant phenology: Mature foliage provides abundant feeding sites, encouraging infestation.
- Weather patterns: Warm, dry spells followed by brief moisture periods favor egg hatching and larval survival.
Monitoring protocols recommend weekly inspections from June onward. Sampling methods such as leaf brushing or sticky traps help detect early signs before the population peaks. Once density exceeds 10 mites per cm² of leaf surface, intervention is advised.
Control strategies appropriate for the late‑summer peak:
- Cultural practices: Remove heavily infested leaves, rotate crops, and ensure adequate plant spacing to improve air circulation.
- Biological agents: Release predatory mites (e.g., Phytoseiulus persimilis) early in the season to establish a suppressive population before the second increase.
- Chemical treatments: Apply acaricides with short residual activity only when economic thresholds are surpassed, rotating active ingredients to prevent resistance.
Understanding the environmental cues and host dynamics that drive the late‑season escalation enables timely management and reduces crop loss.