Bay Area county offices swarmed with calls to treat wasp nests

At least three Northern California counties are reporting a rise in the number of requests they've received to remove wasp nests. Scroll ahead to find out how to control insects near your home this summer. At least three Northern California counties are reporting a rise in the number of requests they've received to remove wasp nests. Scroll ahead to find out how to control insects near your home this summer. Photo: Steven Resell / EyeEm/ Getty Images Photo: Steven Resell / EyeEm/ Getty Images Image 1 of / 14 Caption Close Bay Area county offices swarmed with calls to treat wasp nests 1 / 14 Back to Gallery

Calls to report wasp nests are occurring more frequently than usual this year.

As the Sacramento Bee reports, the Sacramento-Yolo Mosquito & Vector Control District, which usually receives calls about yellow jackets in the late summer or fall, is already hearing from locals concerned about vicious wasps in their area.

In one recent case, district manager Gary Goodman said, the organization treated "nearly 90" yellow jacket nests from a 5-acre property near eucalyptus groves. "When you consider that each nest can have hundreds to thousands of yellow jackets," he said, "this can quickly become a threat to residents."

However, Sacramento County isn't the only area in Northern California to report a change in the number of calls to treat nests with insecticide. Both Contra Costa County and San Mateo County report receiving a high number of requests to rid property owners of dangerous wasp populations.

"We are definitely getting more than we did in the last couple years," says Megan Sebay, the public health and education outreach officer with the San Mateo County Mosquito and Vector Control District. Noting that it's not unusual to receive these calls at this warm time of year from residents, Sebay says that they are receiving "more than usual."

Contra Costa County also reports a similar increase in the volume of calls, and officials at the East Bay's mosquito and vector control district suspect it may have something to do with the end of the drought. "We believe is has to do with all the rain," says Deborah Bass, the organization's public affairs manager. "That creates a lot of food and allows for the yellow jackets to stay healthy, so their numbers increase."

Bass also says that they believe more may be around because the yellow jacket population didn't disappear in the winter, which they tend to do. "We're seeing multiple entry points (into the nest), meaning they didn't die out."

By this time in 2014, Contra Costa County received 231 calls to treat nests with insecticide. In 2015, they received 94, and last year, they got 230 calls. So far this year, however, they've had 376 requests.

The most important thing, both Sebay and Bass say, is to know what to do if you encounter a nest.

Bass says many people try to swat at a wasp to shoo it away, but that's a bad idea. "When they're in fear, they release a pheromone to tell other yellow jackets to come to their aid," she says, adding that it's also important to know what they're attracted to. "They're always looking for meat and sugar, which is why backyard barbecues are so enticing."

Sebay also advises locals to call their nearest mosquito and vector control district center rather than approaching a nest. "If you haven't yet been gotten stung, don't (get stung by going near them)," she says. "Give us a call and we can safely remove (wasps)." Sebay also notes that the treatment is free, because the service is paid for by property taxes.

Alyssa Pereira is an SFGATE staff writer. Email her at apereira@sfchronicle.com or find her on Twitter at @alyspereira.

