Parasitology



Tick ecology: processes and patterns behind the epidemiological risk posed by ixodid ticks as vectors


S. E. RANDOLPH a1c1
a1 Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK

Article author query
randolph se   [PubMed][Google Scholar] 

Abstract

The population ecology of ticks is fundamental to the spatial and temporal variation in the risk of infection by tick-borne pathogens. Tick population dynamics can only be fully understood by quantifying the rates of the demographic processes, which are influenced by both abiotic (climatic) factors acting on the free-living tick stages and biotic (host) responses to the tick as a parasite. Within the framework of a population model, I review methods and results of attempts to quantify (1) rates of tick development and the probability of diapause, (2) the probability of questing for hosts by unfed ticks, (3) the probability of ticks attaching to a host, and (4) tick mortality rates. Biologically, these processes involve the physiological and behavioural response of ticks to temperature, moisture stress and day length that result in specific patterns of seasonal population dynamics and host relationships. Temperate and tropical patterns will be illustrated with reference mostly to Ixodes ricinus and Rhipicephalus appendiculatus, respectively.


Key Words: Ticks; ecology; epidemiology; demographic processes; population models.

Correspondence:
c1 Tel: ++(44) 1865 271241. Fax: ++(44) 1865 271240. E-mail: sarah.randolph@zoology.ox.ac.uk


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