San Gabriel Valley Releases 30,000 Sterilized Mosquitoes Weekly as West Nile Activity Rises
Updated
Updated · LAist · Jul 20
San Gabriel Valley Releases 30,000 Sterilized Mosquitoes Weekly as West Nile Activity Rises
2 articles · Updated · LAist · Jul 20
Summary
Bassett Park scientists in the San Gabriel Valley began releasing 30,000 sterilized male Aedes aegypti mosquitoes each week, with nearly 500,000 planned by the end of October.
The SIT program aims to suppress the invasive species by having sterilized males mate with females, producing no viable offspring and gradually cutting mosquito numbers.
Health officials are escalating control efforts as West Nile virus spreads at rates not seen nationally in two decades and infected mosquitoes in Southern California reached June levels not seen until August last year.
Southern California has reported two human West Nile cases this summer, while officials warn Aedes aegypti also carries dengue, Zika and yellow fever after L.A. County's 2024 local dengue outbreak.
Similar pilot programs are already running in Sunland-Tujunga and Mission Viejo, but officials say removing standing water remains the most immediate defense while the mosquito releases are still being tested for scale.
As millions of modified mosquitoes are released in California, what are the unforeseen ecological risks?
As climate change brings tropical diseases north, is genetic pest control our only option?
Integrated Mosquito Control in San Gabriel Valley 2026: West Nile Virus Trends and the Launch of the Sterile Insect Technique (SIT) Program
Overview
The San Gabriel Valley Mosquito & Vector Control District (SGVMVCD) maintains year-round surveillance and testing for West Nile virus (WNV) and other mosquito-borne diseases, ensuring continuous oversight of mosquito populations and early detection to protect public health. With the first human cases of WNV reported in the current season, residents are reminded to take proactive steps against mosquito bites and breeding. Hot weather creates ideal conditions for mosquitoes, increasing the risk of bites and disease spread. These efforts highlight the importance of ongoing monitoring, public awareness, and community action to reduce mosquito threats in the region.