05/06/2026
VENTURA, California – As temperatures continue to rise this May, Ventura County residents are encouraged to take steps to prevent mosquito breeding and protect themselves from bites as peak mosquito season begins. Mosquito activity started earlier than usual this year due to above-average temperatures, including the warmest March on record, along with increased rainfall. In addition to native mosquito species that can transmit West Nile Virus (WNV), the invasive Aedes aegypti mosquito has become established in Ventura County.
Unlike many native mosquitoes, Aedes aegypti mosquitoes are aggressive daytime and nighttime biters that thrive in neighborhoods and around homes and businesses. They can breed in as little as a teaspoon of standing water and are capable of transmitting viruses including dengue, Zika, chikungunya, and yellow fever. California has experienced locally transmitted dengue cases in recent years, including cases reported in 2023, 2024, and 2025. Infected travelers can introduce dengue into areas where Aedes aegypti mosquitoes are present, creating the potential for local transmission.
The best way to reduce mosquito populations is to eliminate standing water where mosquitoes lay eggs. Common breeding sources include buckets, plant saucers, toys, tarps, drains, and other outdoor containers that collect water. Residents are encouraged to regularly inspect their properties and remove standing water.
The Ventura County Environmental Health Division and Ventura County Public Health recommend the following precautions:
- Ensure doors and windows have tight-fitting screens without holes
- Wear loose-fitting long sleeves and pants when mosquitoes are active
- Use EPA-approved insect repellents containing DEET, picaridin, oil of lemon eucalyptus, PMD, or 2-undecanone
- Eliminate all standing water sources in and around homes
Residents can also:
- Report mosquito activity or standing water by calling the Mosquito Complaint Hotline at 805-658-4310 or filing a report online at eco.vcrma.org
- Request mosquito-eating fish for ornamental ponds and water features by calling 805-662-6582
- Report dead birds for West Nile Virus testing by calling 877-WNV-BIRD (877-968-2473) or visiting westnile.ca.gov
For more information about mosquito prevention and control in Ventura County, residents can visit the Environmental Health Division Vector Control Program webpage.