The western black-legged tick, Ixodes pacificus, in the Sutter Buttes.

The western black-legged tick, Ixodes pacificus, was collected from Huff Canyon in the Sutter Buttes in north central California, Sutter County. The Sutter Buttes are within the Sacramento Valley and outside the normal distribution of I. pacificus in California. Adult I. pacificus were collected via flagging as they quested along deer trails; subadult life stages were collected from three species of lizard, Elgaria multicarinata, Sceloporus occidentalis, and S. graciosus. Adult ticks were tested for the presence of spirochetes using the standard IFA with a monoclonal antibody specific for OSPA. Of the ticks tested, 3.3% were identified as positive for the presence of the spirochete Borrelia burgdorferi. These results present the first published account of Ixodes pacificus as well as the first detection of B. burgdorferi in the Sutter Buttes, Sutter County, California.