Mosquito surveillance data reports the abundance of various species of mosquitoes in San Mateo County.
Different mosquito species have different seasonal life cycles, bite different hosts at different times of day, and transmit different diseases. It’s important for District staff to know what mosquito species are present in order to minimize annoyance and, more importantly, disease risk to humans and domestic animals.
These graphs track the number of mosquitoes of each species (vertical axis) by month (horizontal axis). These are frequently compared to a five-year average of each mosquito species by month, allowing staff to determine whether we have more, less, or about the same mosquito populations as most years.
This table and graphs show the average number of mosquitoes collected per CO2 trap per night during the month of March compared to the five-year average for the six most common mosquito species in San Mateo County. All species were collected in numbers averaging less than five per trap, which is typical for March. Mosquito species that typically emerge in spring, such as Aedes sierrensis and Culex erythrothorax, have not yet been detected in traps, probably because cool and wet wintry weather continued through March.
The table below shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in September 2017, compared with the five-year average during September.
Click on the graphs to see the year long monitoring data of the average number of mosquitoes captured in CO2 traps per night throughout 2017 and the five-year average for each month of the year.
The table shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in July and August 2017 compared with the five-year average during July and August
Monthly abundances of five common mosquito species in San Mateo County, Aedes dorsalis, the summer salt marsh mosquito, Culex erythrothorax, the tule mosquito, Culex pipiens, the northern house mosquito, Culex tarsalis, the western encephalitis mosquito, and Culiseta incidens, the cool weather mosquito.
Click on the graphic below to see the population fluctuation this spring and summer.