Ecology of tick vectors of American spotted fever.

The author reviews the natural history of the tick vectors of American spotted fever. The discussion concerns the ecology of the Rocky Mountain wood tick, Dermacentor andersoni, the American dog tick, Dermacentor variabilis, and the lone-star tick, Amblyomma americanum, all of which are proven vectors of Rocky Mountain spotted fever to man. Also included are the rabbit tick, Haemaphysalis leporispalustris and Dermacentor parumapertus, which very rarely bite man but which are considered of importance in maintaining and distributing Rickettsia rickettsi, the etiological agent of Rocky Mountain spotted fever, in nature. Brief reference is also made to recently developed techniques for studying the ecology of tick vectors.