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.
For more information about how the District traps mosquitoes for disease and population surveillance, see Mosquito Trapping and Pools.
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.
The table and graphs below show the average number of mosquitoes collected per CO2 trap per night during the month of October, compared to the five-year average for the six most common mosquito species in San Mateo County. Counts for all species are averaging below ten per trap, which is consistent with the five-year average. Although Culex pipiens had a late peak in September, it has returned to normal levels, and we expect it to further decrease through the colder months.
These table and graphs show the average number of mosquitoes collected per CO2 trap per night during the month of July and August compared to the five-year average for the six most common mosquito species in San Mateo County. The peak of Cx. erythrothorax, the tule mosquito, in July and August has subsided. Although the abundance is still above average, it should continue to lower as autumn progresses. Cx. pipiens, the northern house mosquito was collected in atypically high numbers during September. The high numbers of Cx.
These tables and graphs show the average number of mosquitoes collected per CO2 trap per night during the month of July compared to the five-year average for the six most common mosquito species in San Mateo County.
These table and graphs show the average number of mosquitoes collected per CO2 trap per night during the month of June compared to the five-year average for the six most common mosquito species in San Mateo County. All species increased in abundance during June, except Aedes sierrensis, which kept consistent numbers from May. The number of collected Culex pipiens, the most abundant summer mosquito, remains below average. This is likely a result of pro-active seasonal catch basin control, utilizing mapping software in the field for more effective treatments.
This table and graphs show the average number of mosquitoes collected per CO2 trap per night during the month of May compared to the five-year average for the six most common mosquito species in San Mateo County. All species increased in abundance during May, except Aedes washinoi, which typically peaks in March and April. The number of collected Culex pipiens, the most abundant summer mosquito, is below average. This is likely a result of pro-active seasonal catch basin control, utilizing mapping software in the field for more effective treatments.
This table and graphs show the average number of mosquitoes collected per CO2 trap per night during the month of April 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 April. Although mosquito trap counts are slightly higher than in March, the cool temperature at night through April combined with control efforts has kept adult mosquito abundance low.
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 February 2018, compared with the five-year average during February.
The table below shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in January 2018, compared with the five-year average during January.
The table below shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in December 2017, compared with the five-year average during December.
The table below shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in November 2017, compared with the five-year average during November.
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 below shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in October 2017, compared with the five-year average during October.
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 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
The table shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in June 2017 compared with the five-year average during June.
The table shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in May 2017 compared with the five-year average during May.
The table shows the proportions of common mosquitoes in San Mateo County that were collected in carbon dioxide baited traps in April 2017 compared with the five-year average during April.
