Keeping San Mateo County pest free

EO: I was born and raised in San Mateo County and always had an interest in the outdoors and wildlife. The work that we do is a nice blend of helping my community and responsibly working with nature.

DJ: How did you come to work with the San Mateo County Mosquito and Vector Control District?

EO: I started with the district as a seasonal vector control aide in the summer of 2018, and, at the end of the season, I was hired full-time as a vector control technician. Coming to work for the district was a blend of opportunity and timing. I was an English major in college and had many odd jobs before the seasonal opportunity came up. I quickly discovered it to be a career that I was passionate about. Our extensive on-the-job training gave me the knowledge and technical skills specific to vector control, and I was able to bring other skills to communicate, educate and help people solve problems.

DJ: What does “vector control” mean?

EO: In our field, ‘vector’ is an animal that can spread disease or cause discomfort/injury. Our work focuses mainly on mosquitoes that bite and can spread diseases to humans. However, since ticks, rodents and other animals can spread diseases, our work also includes reducing the risk of them coming into contact with people. Yellow jackets, since they can bite and sting, and since some people can have a severe allergic reaction, also fall into the category.

DJ: What services does the district offer?

EO: Most of what we do is mosquito control. There is a lot of behind-the-scenes work we do checking for mosquitoes in a variety of water sources throughout the county and using appropriate mosquito control treatments to control mosquitoes. However, we also offer several other services that residents can request. Our most used service, especially in the summer months, is yellow jacket nest treatment; as long as someone knows where the yellow jacket nest is, we can visit to treat and/or remove the nest. Other services include rodent inspections — we can check around a home for potential rodent entry points and give advice on how to correct those issues to lower the chance of a rat or mouse entering a home. Similarly, we can visit a property to give general advice about making your property less attractive to wildlife. We have mosquito fish we can provide for situations where someone has a swimming pool they are no longer using, a fishpond, or a decorative fountain. The mosquito fish eat mosquito larvae and help control mosquito populations. Our staff regularly collect mosquitoes and ticks using standardized sampling methods to test for disease pathogens. And we offer community education to schools and other interested groups. Since our funding comes from property tax dollars, we don’t charge a fee for any of the services.

DJ: What does a typical day look like for you in your work with the district?

EO: The best part of the job for me is that I do not necessarily know what each day will include. While there are always routine surveillance and inspections, new challenges come up daily, and any issue that does come up can be highly specific to that case. On any given day, I could be hiking through a restored wetland looking for salt marsh mosquitoes, removing a yellow jacket nest from under a sidewalk, or inspecting a house to help a resident learn how to keep rats out of their home. I really enjoy the diversity of our services and dynamic work environment, the reward of helping others, and sharing knowledge with the public to help people understand the problem at hand and develop the safest, most effective science-based solution.

DJ: How do you identify areas with high mosquito populations?

EO: We use a few different ways to know where to concentrate our efforts. We encourage people to call us if they are being bitten by mosquitoes. We use mosquito traps to collect adult mosquitoes — we count the number of mosquitoes in the trap and identify the different species in the trap. There are about 20 different kinds of mosquitoes in San Mateo County. They are found in different types of habitats and have different behaviors. So using the information from the mosquito traps helps us focus our efforts. We also have a database with known water sources in it, to help us quickly know where to check for mosquito larvae. But there are always new water sources popping up, and so we’re frequently going door-to-door in a neighborhood to check yards and crawl spaces (you wouldn’t believe the number of under-home puddles we’ve found from pipes that people didn’t even know were leaking!).

DJ: What methods do you use to control mosquitoes?

EO: The District uses integrated pest management to control mosquitoes. This means we have a suite of methods, and we chose the method most appropriate for the specific situation we’re seeing in the field. Our work particularly focuses on controlling mosquitoes when they are larvae in water, so most of our work involves checking water for larvae, dumping/draining standing water, using biological control methods (like mosquito fish or bacteria-based products), and sometimes using chemical control (like insect growth regulators and other products).

DJ: What is the biggest challenge you face when trying to control mosquito populations?

EO: Our work goes unnoticed when we have done a good job. People often say that they never notice mosquitoes where they live, and that is because of the work that goes into routinely surveying, inspecting and treating mosquito breeding habitats before the flying biting adults emerge. The importance of preventative efforts can easily be overlooked when someone is not experiencing mosquito bites.

DJ: What can the public do to help with mosquito control?

EO: Dump/change standing water weekly, and call us if the water is too big for you to dump. Even in winter when it’s cold and one might not necessarily be conscious of mosquito risk, it is important to be vigilant and proactive, so our community is not overwhelmed in the summer when disease risk is at its highest. Call us when you are getting bitten by mosquitoes at your house so that we can find the water source and control the population.