When do encephalitis ticks wake up? - briefly
They emerge from dormancy in early spring, usually March‑April, and remain active through late summer. Peak activity is observed in May and June.
When do encephalitis ticks wake up? - in detail
Ticks that transmit encephalitis become active primarily during the warm months of the year. Activity starts in early spring, usually when temperatures consistently exceed 7 °C (45 °F), and continues through late autumn, ending when nightly lows drop below 5 °C (41 °F). The two peak periods are late spring (May–June) and early autumn (September–October), when questing behavior reaches its maximum.
Daily activity follows a predictable pattern. Ticks ascend vegetation to attach to passing hosts during the cooler parts of the day. Peak questing occurs in the early morning (approximately 04:00–09:00) and again in the late afternoon to early evening (approximately 16:00–20:00). Midday heat and low relative humidity suppress movement; activity declines sharply when ambient humidity falls below 80 % or temperature rises above 30 °C (86 °F).
Environmental cues that trigger awakening include:
- Temperature rise above the 7 °C threshold.
- High relative humidity, typically above 80 %.
- Photoperiod changes, with longer daylight hours in spring and autumn stimulating increased questing.
- Host availability, especially the presence of small mammals and birds during breeding seasons.
Life‑stage differences affect timing. Nymphs, which are most often responsible for transmitting encephalitis viruses, emerge in late spring and display the same diurnal peaks as adults but are more sensitive to humidity fluctuations. Larvae appear earlier in the season and are active for a shorter window, generally from April to early June.
In summary, the activation window for encephalitis‑carrying ticks spans from early spring to late autumn, with heightened activity during cooler morning and evening hours, contingent on temperature, humidity, and host presence.