Published by: The PCC Research Team | Last Updated: July 22, 2026
The Orange County Mosquito and Vector Control District (OCMVCD) has issued an official notice for upcoming residential truck-mounted treatments in Buena Park. Following active surveillance and elevated disease threat indicators, vector control units will deploy Ultra-Low Volume (ULV) adulticide applications during the overnight hours from Thursday, July 23rd through Saturday, July 25th, 2026.
These applications are specifically designed to reduce adult mosquito populations and curb the transmission risk of West Nile virus across densely populated residential sectors.
Treatment Schedule & Deployment Parameters
| Application Dates | Time Window | Method & Material | Target Zone |
|---|---|---|---|
| July 23, 24, & 25, 2026 | 12:00 AM – 5:00 AM | Truck ULV / DeltaGard | Buena Park Grid (See Map Below) |
Interactive Target Area Map
Property owners in Buena Park can search their exact street address using the official interactive ArcGIS boundary map provided by the District below:
The Sentinel Science: Understanding DeltaGard & Late-Night ULV Fogging
Public health applications of DeltaGard utilize an EPA-registered synthetic pyrethroid formulated with deltamethrin. Understanding the operational mechanics helps address common homeowner concerns:
- Ultra-Low Volume (ULV) Droplet Dynamics: Specialized truck nozzles aerosolize the liquid into micro-droplets (10–30 microns in diameter) that float on late-night thermal currents to make direct contact with flying mosquitoes in mid-air.
- Why Midnight to 5:00 AM? Overnight windows are specifically selected because local Culex quinquefasciatus (the primary West Nile vector) are actively foraging, while beneficial pollinators like honeybees are safely enclosed in hives.
- Rapid Environmental Breakdown: DeltaGard features low residual persistence, breaking down quickly under direct natural UV light after sunrise to prevent chemical accumulation on ground surfaces.
Recommended Homeowner Precautions
- Ventilation Management: Keep windows and exterior doors closed between midnight and 5:00 AM during treatment nights, and set central AC units to internal recirculation mode.
- Pet & Outdoor Property Protection: Bring domestic pets indoors overnight and bring pet water dishes or toys inside during scheduled spray windows.
- Standing Water Audits: Truck applications target adult flying mosquitoes, but eliminating larval breeding sources requires eliminating standing water in pot saucers, rain gutters, and unmaintained yards.
Notice: Weather conditions such as high winds or low-level rain can delay or postpone truck applications. If viral activity persists in regional trapping stations, treatments may continue throughout the active vector season.