The District controls mosquitoes in breeding sources created by standing water in wetlands, catch basins, drains, roadside ditches, flood channels, ravines and similar locations on public land. Control methods include routine larvicide operations throughout the year and adulticide treatments as needed. The District works with city, county, state, and federal agencies to permanently correct breeding sources wherever advisable.

The District has over 100 mosquito traps placed throughout the County. The trapped mosquitoes are quantified for abundance and tested for possible diseases they could be carrying (i.e. West Nile virus, St. Louis and Western Equine Encephalitis).

The Orange County Mosquito and Vector Control District uses two different types of traps: a carbon dioxide baited trap and a gravid mosquito trap.

Carbon Dioxide Baited Trap

The carbon dioxide trap is used as an attractant for recently mated females. After females mate, they need to find a blood-source to be able to produce eggs. The carbon dioxide trap mimics an animal's breathing emissions. 

Gravid Mosquito Trap

The gravid trap is a foul-smelling trap that egg-laying female mosquitoes are attracted to as a potential place to lay their eggs.

Other Surveillance Methods

Besides surveillance conducted by our lab every week, our inspectors are also conducting daily surveillance by looking for mosquito breeding sources in their zones. In between service requests, our inspectors are checking drains, gutters, and ditches. Anything that can hold water for longer than one week has the potential to become a breeding source.