| Risk Assessment and Management Solutions for Arthropod-borne and Infectious Diseases |
Seasonal risk of exposure to Rocky Mountain wood ticks
Adult Rocky Mountain wood ticks are
active during March-July in Colorado.
Ticks were collected from one part of
the high elevation south-facing Tunnel
site in late March while another part of
the site was still covered in snow.
Very few ticks remained active into
July, when the weather is becoming
too warm and dry and they perish from
desiccation.
Peak tick numbers occur from mid-April
to late May. This is fortunate because
peak tick activity occurs before the
summer peak in hiking and other activities placing people at risk for tick exposure.
Seasonal activity patterns were similar for
ticks collected at elevations ranging from
5,870 ft at Young Gulch to 8,100 ft at Tunnel.
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Site locations and distribution of montane ponderosa pine habitat | |
| From: Eisen 2007. Seasonal pattern of host-seeking activity by the human-biting adult life stage of the Rocky Mountain wood tick, Dermacentor andersoni (Acari: Ixodidae). Journal of Medical Entomology 44: 359-366. | ||
Rocky Mountain wood ticks were collected more commonly from grass than from brush or juniper in Poudre Canyon (5 sites) and Rocky Mountain National Park (5 sites).
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| At Poudre Chapel, rapid increases in tick numbers in late March - early April followed a stretch of days with daily maximum temperatures exceeding 40 °F. Rapidly declining tick numbers in mid- to late May were associated with daily max. temp. consistently >70 °F and daily min. relative humidity commonly falling below 20%. |
| From: Eisen 2007. Seasonal pattern of host-seeking activity by the human-biting adult life stage of the Rocky Mountain wood tick, Dermacentor andersoni (Acari: Ixodidae). Journal of Medical Entomology 44: 359-366. |