Officials at San Mateo Mosquito and Vector Control District (SMCMVCD) remind residents that winter is the season for the western black-legged tick (Ixodes pacificus). This tick is the primary vector for Lyme disease and other tick-borne illnesses in San Mateo County. “Most people think of mountain lions and coyotes as the major risks when enjoying outdoor activites. We’d like to remind people that some real threats come in much smaller packages,” said Laboratory Director Angie Nakano.
These table and graphs show the average number of mosquitoes collected per CO2 trap per night during the month of November compared to the five-year average for the six most common mosquito species in San Mateo County. Counts for all species continue to decline as we progress into the cooler season. All species are near or slightly below average for this time of year.
This table contains the number of each type of service request in November 2018 compared to the three-year average in November. The total number of service requests is somewhat below average, mainly because we have had fewer than typical mosquito-related requests. The number of yellowjacket and wasp service requests continued in a steep decline, shown in the graph, and will likely remain low until spring.
At the District, the majority of our tick surveillance focuses on three tick species, Ixodes pacificus, (western black-legged tick), Dermacentor varabilis, (American dog tick) and Dermacentor occidentalis, (Pacific coast tick). These ticks quest for hosts in the vegetation along trails, and are easily picked up by hikers and dogs. While these three species present the greatest risk of disease transmission to humans and pets, there are many more species of ticks that live in San Mateo County that we do not collect as part of our usual surveillance.