District laboratory staff conducted a rodent survey for hantavirus with California Department of Public Health (CDPH) staff on June 4-5 in La Honda. Peromyscus truei (pinyon mice) and Peromyscus californicus (parasitic mice) were trapped and blood samples were taken for testing. Kidney samples from any mice with positive blood samples will also be tested by the CDPH to be used for a study of the geographical distribution of different hantavirus strains in California.
During the summer months, the District receives numerous calls regarding yellowjackets and paper wasps. These social wasps both have yellow and black markings and are common in San Mateo County, but they have important behavioral differences.
It’s summer and that means peak season for the dog tick and Pacific coast tick (collectively called Dermacentor ticks)! These large, brown-colored ticks are very prevalent this time of year along the edge of trails and in brushy areas with tall grass all throughout California. Unfed, they can be nearly three times as large as the black-legged ticks that are prevalent during the winter and spring and can engorge to the size of a grape if left attached to repletion.