and Genospecies in Northern California.

The lato (s.l.) complexes of and include pathogenic genospecies each with distinct ecologies in northern California, yet, most work conflates the genospecies of each pathogen into one lato species. Detailed understanding of the differences in geographic distributions and ecology among genospecies is lacking. We aimed to evaluate whether two and two genospecies in high-risk locations in coastal northern California were spatially clustered and if presence of a particular genospecies was associated with geographical site, host species, or other demographic or ecological variables. DNA sequencing was performed to differentiate genospecies of Borreliae and Anaplasma from PCR-positive dusky-footed woodrats () and sciurids (chipmunks, spp., and Douglas squirrels, ) at four sites in northwestern California. Logistic regression was performed to assess associations of genospecies with the predictor variables host species, host sex, site, season, and year. Spatial clustering was assessed using a Poisson spatial scan statistic in SaTScan. Host species was a significant predictor for , stricto (s.s.), s.s., and the DU1 genospecies. Woodrats were significantly more likely to be PCR-positive for and DU1 genospecies, while s.s. and s.s. were significantly associated with sciurids. We report a single in an Allen's chipmunk () from the Hoopa Valley Tribal Reservation. A significant spatial cluster of s.s. was detected at Hendy Woods State Park in Mendocino County. These results highlight the need to better understand genospecies partitioning according to host species to further assess human risks, aid in future surveillance, and inform targeted research.