Marin‑Sonoma Mosquito & Vector Control reports zero West Nile activity in 2024, flags invasive Aedes and new technologies

The Marin‑Sonoma Mosquito and Vector Control District presented its 2024 activity summary and 2025 priorities at the Cotati City Council meeting.

District manager Peter Bonkert said operations in 2024 returned zero local detections of West Nile virus in Marin and Sonoma counties, though statewide activity continued. ‘‘Of our collections tested in 2024, we found zero West Nile virus positives,’’ Bonkert said.

The district described its surveillance and operational footprint: about 1,600 adult mosquito traps were set in 2024, roughly 40,000 mosquitoes were identified and about 15,000 were tested for disease. The district handled roughly 6,000 service requests and said its annual budget is about $12.1 million.

Public‑health concerns and invasive species Bonkert emphasized two ongoing concerns for the region: the continuing presence of ticks that can carry Lyme disease and the northward spread of invasive Aedes aegypti mosquitoes, which can transmit dengue, Zika and chikungunya where they become established. ‘‘Aedes aegypti is a very challenging urban mosquito that can breed in a capful of water and it’s been detected in neighboring counties; the pattern is one of northward movement,’’ Bonkert said.

The district outlined integrated vector management strategies that combine source reduction, biological control (including the use of mosquito fish), targeted pesticide application when needed, and public outreach to reduce breeding habitat. Bonkert also described technology pilots including 3‑D‑printed traps developed in‑house and emerging biological control and sterile‑male techniques used elsewhere.

Services, outreach and equity Bonkert said the district provides yellow‑jacket removal, rodent exclusion advice, school outreach (the district reported nearly 300 classroom presentations reaching roughly 6,500 students in 2024), and bilingual materials. The district also performs tick sampling and education and stated it coordinates with county public health on other pathogens, such as avian influenza testing when appropriate.

Council members and residents asked about local West Nile history, bilingual outreach and enforcement for rodent issues; Bonkert said the district’s materials are available in Spanish and it partners with code enforcement and county public health on cross‑jurisdictional issues.

Ending Council members thanked the district for the briefing and for appointing Cotati council member Susan Harvey to the district board.

Speakers quoted or referenced in this article Peter Bonkert, District Manager, Marin‑Sonoma Mosquito & Vector Control District.