Operations Staff


Meet Your Technician

group photo of technicians

The San Mateo County Mosquito and Vector Control District staff consists of certified vector control technicians and other professionals who are dedicated to safeguarding the health and comfort of the residents of San Mateo County.

To to learn more about your city’s Vector Control Technician, please click on their name.

Our Vector Control Technicians

City Technician
Atherton Walter Bruj
Belmont Kim Keyser 
Brisbane Devon MacDonald
Burlingame Sean Jones
Colma Devon MacDonald
Daly City Ryan Thorndike
East Palo Alto Walter Bruj
Foster City Stephanie Busam 
Half Moon Bay Ryan Thorndike
Hillsborough Sean Jones
Menlo Park Walter Bruj
Millbrae Devon MacDonald
Pacifica Ryan Thorndike
Portola Valley David Allen
Redwood City Evan Ostermann
Redwood Shores Kim Keyser 
San Bruno Devon MacDonald
San Carlos Kim Keyser 
San Mateo Eric Eckstein
South San Francisco Devon MacDonald 
Woodside David Allen

Casey Stevenson
Field Operations Supervisor

About Casey:

A District native, Casey began his career with San Mateo Mosquito and Vector Control District in 2008 as a seasonal Vector Control Technician. Later that year he was hired as a permanent Vector Control Technician and subsequently promoted to his current position as Field Operations Supervisor. Casey is a graduate of California State University Chico, where he received a Bachelors degree in communications.


David Allen
Vector Control Technician

About David:

David holds a Bachelor of Arts in Environmental Science and an Associate of Arts in Wildlife Management. Before joining the District in 2012, David owned a snake removal and consultation company which he operated in Northern California and Arizona.  David’s other professional experience includes herpetological conservation projects in South Africa, primate linguistics research, public education, and wildlife/natural resource management.


Stephanie Busam
Vector Control Technician

About Stephanie:

Stephanie Busam has worked at San Mateo County Mosquito and Vector Control District as a Vector Control Technician since January 2005. While she has covered a variety of zones in the county, she is currently working in Belmont and Foster City.


Walter Bruj
Vector Control Technician

About Walter:

A Bay Area native, Walter began his career with the District in the spring of 2015 as a Vector Control Aide II working with the Aedes aegypti team. He was hired on as a permanent Vector Control Technician in October 2015.

Walter’s public sector background includes several years with the Alameda County Agriculture Pest Detection Program and as a park ranger with San Mateo County Parks. In the private sector he worked in video production/multi-media, and he has extensive marine-related experience.


Eric Eckstein
Vector Control Technician

About Eric:

Eric has worked for the District since 2014, first as a seasonal Vector Control Technician before being hired for a permanent position. He has a Bachelor of Science in Microbiology from San Francisco State University, and worked in environmental microbiology before joining the District staff.

Eric is a native of San Mateo County, and a die-hard 49ers fan.


Sean Jones
Vector Control Technician

About Sean:

Sean worked for the District as a seasonal Vector Control Aide in 2015. He joined the staff as a permanent employee in October 2015 providing service in Burlingame and Hillsborough. Sean is a lifelong resident of San Mateo County.

Contact Information:

Office: (650) 344-8592 x16

Fax: (650) 344-3843


Kim Keyser
Vector Control Technician

About Kim:

Kim has worked with San Mateo County Mosquito and Vector Control District since 2004. She studied entomology and acarology in university and has worked in that field for Archbold Biological Station in Florida and San Mateo County Department of Agriculture/Weights and Measures in California.


Devon Macdonald
Vector Control Technician

About Devon

Devon worked for the District as a Seasonal Vector Control Aide during the 2016, 2017, and 2018 seasons. He joined the District staff as a permanent Vector Control Technician in 2019. Devon is a life-long resident of the Bay Area. He graduated from San Mateo High School in 2012. He attended Lone Star College in Montgomery County, Texas, in 2014. He has a background in residential construction. Devon enjoys being outdoors and spending time with his friends and family.


Evan Ostermann
Vector Control Technician

About Evan

Evan started with the district as a Seasonal Vector Control Aide in the Summer of 2018. At the end of the season he was hired full-time as a Vector Control Technician. Evan was born and raised in San Mateo County.


Ryan Thorndike
Vector Control Technician

About Ryan:

Ryan Thorndike started with the District in May of 2014 as a seasonal employee helping to eradicate the Aedes aegypti mosquito (also known as the Yellow Fever mosquito) in West Menlo Park.  He was hired as a full-time technician in January of 2015. His zone includes Daly City and the coast. Ryan is a lifelong resident of San Mateo.

Contact Information:

Office: (650) 344-8592

Fax: (650) 344-3843