California Mosquito Awareness Week — Orange County

Orange County is marking California Mosquito Awareness Week from April 19 to 25 with a countywide push to dump standing water before mosquito season peaks. (ocvector.org) The Orange County Mosquito and Vector Control District said warmer weather signals the start of mosquito season, which it says runs through October. The district’s 2026 campaign tells residents to work together to protect “families, friends, and neighbors” across the county. (ocvector.org) Santa Ana amplified that message in its April 17 COSAS newsletter, which said the district is urging residents to take “simple, proactive steps” during the April 19–25 observance. The city pointed readers to local prevention guidance as outreach moved into neighborhoods. (santa-ana.org) The basic problem is small containers of water: buckets, plant saucers, clogged drains, birdbaths, and other spots where mosquitoes can lay eggs. The district says mosquito control is a “shared responsibility” because breeding sites often sit on private property, indoors and outdoors. (ocvector.org) Orange County’s concern is not just itchy bites. The district says invasive Aedes mosquitoes can spread dengue, Zika, chikungunya, and yellow fever under different response scenarios, including travel-related cases and local transmission. (ocvector.org) Those Aedes mosquitoes — often called ankle biters because they commonly bite low on the body — first appeared in Orange County in 2015 and are now common throughout the county, according to the district. Dengue prevention, the district says, starts with cutting mosquito breeding where people live. (ocvector.org) The district says residents should eliminate all standing water from their property because Aedes eggs can survive for years and hatch when conditions turn favorable. That makes weekly cleanup more important than one-time spraying after mosquitoes appear. (ocvector.org) Orange County also uses a broader control program beyond public reminders. The district says it bases larval and adult mosquito treatments — by truck, backpack, drone, or aircraft — on surveillance data and disease activity that indicate a threat to human health. (ocvector.org) The agency is also testing a sterile insect technique program aimed at Aedes aegypti, releasing sterilized males so eggs do not hatch and populations fall over time. The district describes that work as part of an integrated mosquito management strategy. (ocvector.org) For Orange County residents this week, the public-health ask is simple and local: check yards, patios, and indoor containers before water sits long enough for mosquitoes to breed. The district says the campaign runs through April 25, but mosquito season in Orange County lasts through October. (ocvector.org)