Size
adult body length about 3 mm
Identification
Adult and Nymph: legs, head, and thoracic plate black; female abdomen dark reddish; male abdomen blackish; 8 legs; nymph about half as large as adult
Larva: 6 legs, lighter color, and about one-quarter as large as adult
Range
western United States and British Columbia (range does not overlap with
Ixodes scapularis, the Deer Tick - see
distribution map)
Habitat
forests, north coastal scrub, high brush, and open grasslands; nymphs are commonly found on moss-covered tree trunks
Season
may be present any time of year
Food
adults feed on blood of large mammals such as deer, dogs, coyotes, horses, and humans
subadult stages feed on blood of lizards and small rodents
Remarks
The Western Black-legged Tick is a vector of the Lyme Disease Borrelia burgdorferi spirochete, Babesia microti, and the equine granulocytic Ehrlichiosis equi rickettsia
Internet References
various life stage images and other info (Rhode Island Dept. of Health)
adult female image (U. of California at Berkeley)
adult images and comparison with other tick species (Canadian Lyme Disease Foundation, British Columbia)
nymphal habitat; PDF doc (Ted Slowik and Robert Lane, Journal of Vector Ecology)
as a vector of Ehrlichia equi in horses (PubMed, National Institutes of Health)
as a vector of Borrelia burgdorferi (PubMed, National Institutes of Health)
as a vector of organisms that cause
Babesiosis,
Lyme Disease, and
Ehrlichiosis (Rhode Island Dept. of Health)
distribution maps of several tick species (Centers for Disease Control)
distribution in Canada (Public Health Agency of Canada)
