Wasps are out in big numbers across Contra Costa County and this year’s record rainfall and mild temperatures are to blame.
Wasps from last year lived through the winter along with larvae and queens, according to Deborah Bass with the Contra Costa Mosquito and Vector Control District.
“Right now, the nests are pretty big because they didn't die out, so some of these nests have about 5,000 yellow jackets in them,” Bass said.
In Contra Costa County, a growing number of people are calling for help to get rid of the insects, Bass said.
In 2015, the district received just 94 calls to remove wasp nests in the county. That number jumped to 230 in 2016. In the first seven months of 2017, the district has already fielded 376 calls for help – that’s a 60-plus percent increase.
It's a good idea to stay away from the insects because when one yellow jacket wasp gets alarmed, they all do, Bass said.
“They release a pheromone (that) tells all of the other yellow jackets that there's a problem so that would be hazardous and it's better to call a qualified pest control operator,” she explained.
Mosquito and Vector Control Districts across the Bay Area will get rid of ground wasp nests for free. They will not, however, spray nests in the trees or other above-ground places.