County drops mosquito larvicide in Mission Trails to combat West Nile

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

SAN DIEGO -- County environmental health workers plan to drop bacterium-based larvicide into ponds, rivers and wetland areas near Lake Kumeyaay in Mission Trails Regional Park Wednesday in an effort to kill the larvae of mosquitoes that can transmit West Nile virus.

Helicopter drops larvicide pellets over Mission Trails Regional Park.

Helicopter drops larvicide pellets over Mission Trails Regional Park.

The solid cereal-sized larvicide pellets are released into 48 or so local waterways about once a month during mosquito season. County officials said the bacterium used to kill mosquito larvae will not affect people and pets.

So far this year, five San Diego County residents have tested positive for West Nile. County environmental health officials said 44 of the 45 people who contracted West Nile in 2015 did so after mid-September.

The county is also reminding residents to help control mosquitoes themselves by dumping out standing water around their homes, using mosquito fish to stem breeding in horse troughs, fountains and other water sources, and using insect repellent when outdoors.

The routine larvicide applications are unrelated to recent hand-spraying of a pesticide derived from chrysanthemums to kill adult, invasive Aedes mosquitoes in Grant Hill, South Park, Mount Hope and Normal Heights. All four areas where Pyrenone 25-5 was sprayed over the last couple months were near the home of someone who contracted the Zika virus while traveling.

Notice: you are using an outdated browser. Microsoft does not recommend using IE as your default browser. Some features on this website, like video and images, might not work properly. For the best experience, please upgrade your browser.