Nonremoval drag sampling was conducted in multiple sites in Larimer County, CO, from March to July 2006 to determine the seasonal pattern of host-seeking activity by the human-biting adult life stage of the Rocky Mountain wood tick, Dermacentor andersoni Stiles (Acari: Ixodidae). Four sites, at elevations ranging from 1,790 to 2,470 m, consistently yielded host-seeking ticks. Ticks were active from March until late June; the length of the active period ranged from 84 to 104 d. Based on site-specific linear regression models of increase and decrease in tick host-seeking activity over time, densities of D. andersoni adults were estimated to reach 50% of their peaks between 2 and 11 April, to peak between 21 and 28 April, and to fall below 50% of the peaks between 24 and 27 May. The length of the periods with tick densities exceeding 50 and 75% of the peak was 43–52 and 21–26 d, respectively. Rapid increases in tick numbers in late March to early April followed a stretch of days with daily maximum temperatures exceeding 5°C, whereas rapidly declining tick numbers in mid- to late May were associated with daily maximum temperatures consistently exceeding 20°C and daily minimum relative humidity commonly falling below 20%. Densities of D. andersoni adults exceeded 50% of the peak when daily maximum temperatures were in the 16–19°C range and daily minimum relative humidity was >20%. Finally, tick seasonality may be adapted to local climatic conditions within Larimer County; site-specific daily maximum temperatures at the time of peak tick host-seeking activity in late April were positively associated with site-specific mean daily maximum temperatures for April.
How to translate text using browser tools
1 March 2007
Seasonal Pattern of Host-Seeking Activity by the Human-Biting Adult Life Stage of Dermacentor andersoni (Acari: Ixodidae)
L. Eisen
ACCESS THE FULL ARTICLE
It is not available for individual sale.
This article is only available to subscribers.
It is not available for individual sale.
It is not available for individual sale.
Journal of Medical Entomology
Vol. 44 • No. 2
March 2007
Vol. 44 • No. 2
March 2007
Climate
Colorado
Dermacentor andersoni
seasonal activity