Density and spatial distribution of Ixodes pacificus (Acari: Ixodidae) in two recreational areas in north coastal California

• Published in: The American journal of tropical medicine and hygiene Vol. 62; no. 3; p. 415
• Main Authors: Li, X, Peavey, C A, Lane, R S
• Format: Journal Article
• Language: English
• Published: United States 01-03-2000
• Subjects: Animals; Borrelia burgdorferi Group - isolation & purification; California; Ixodes; Lyme Disease - epidemiology; Lyme Disease - etiology; Nymph - microbiology; Population Density; Prevalence; Rats; Recreation; California
• ISSN: 0002-9637
• DOI: 10.4269/ajtmh.2000.62.415

The density and distribution of Ixodes pacificus was assessed at 2 parks in north coastal California. The density of I. pacificus adults and nymphs varied significantly between years, trails, and sides of trails. Adult ticks occurred on vegetation along sun-exposed trails in January through March, their density (0-1.93 per 20 m) correlated with brush density, trail width, and presence of an uphill slope. Nymphs (0.06-5.10 per 20 m) occurred in leaf litter along shaded trails in May-July. Adult I. pacificus were rare at picnic sites (0.00-0.24 per 20 m), but nymphal densities (0.93-2.37 per 20 m) were comparable with those along some shaded trails. The prevalence of Borrelia burgdorferi in ticks (2.8% overall) did not differ significantly between locations, years, or stages. We conclude that the risk of acquiring Lyme disease in these sites is low, but varies among trails, seasons, and years.