Weather triggers bloom of bugs in Sonoma

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Sonoma Valley experienced a different kind of super bloom this week that had nothing to do with wildflowers. Temperatures exploded and the extra rainy season encouraged early plant growth and an extra flourish of bugs.

“The heavy rainfall that continued into the spring, coupled with the recent high temperatures has generated large quantities of mosquitoes and midges,” said Phil Smith, manager of the Marin/Sonoma Mosquito and Vector Control District.

“In many areas, the Aedes sierrensis ‘tree hole’ mosquitoes are emerging and district staff are working extra hours to assist our local residents,” Smith said. “We are also seeing some salt marsh mosquitoes and are currently working in several areas to ensure that larvae do not turn into biting adults.”

Added Smith: “People are also reporting impressive swarms of gnats and midges, which in general do not bite.”

Sonoma’s temperature hit 88 degrees on both Tuesday and Wednesday with humidity highs of 87 percent and 89 percent, respectively. Average temperatures for April 23 and 24 are 72 degrees, and average humidity levels are 62 and 65 percent, respectively.

Santa Rosa topped out at 93 degrees on Tuesday giving it its hottest April 23 since 1946, according to the National Weather Service; meanwhile Windsor, Petaluma and Healdsburg each reached 98 degrees.

“Nine records were broken or tied on Tuesday” in the North Bay Area, said Anna Schneider, meteorologist with the National Weather service.

A high pressure system with off-shore movement brought in warm and dry air across the region, Schneider said.

The recent warm weather is partly to blame for the burst of bugs.

“The main reason we’re seeing so many insects now is that most of our native insects are adapted to our wet-cool, dry-warm climate” said Richard Dale, executive director of Sonoma Ecology Center. “When the weather warms, that signals overwintering insects to emerge and mate, and other life stages of insects to get busy and grow and reproduce before water is scarce and vegetation dries out. We see a lot of insects emerge as a result.

Though the bugs are pesky, they are necessary, too, he said.

“It’s worth noting that recent studies show that the world’s insects are disappearing fast, and this should be a major concern for all of us. If we like birds, fish, and wildflowers, or the many trees and food plants that need to be pollinated, then we need invertebrates, such as beetles, bees and flies. Even if they are pests sometimes, they are also the base of the food web and we rely on them to survive,” Dale said.

Cooler weather makes it a little easier to put up with the bugs, and Friday is the “beginning of a cooling off period,” Schneider said. There will be a “little deepening of the marine layer” over the weekend, which will help keep temperatures down.

“But we’re still probably looking at highs inland in the low to mid 80s, and mid 70s along the coast,” she said.

Saturday will be a little cooler than Friday, and Sunday will cool off a bit more, Schneider said.

Rain in Sonoma County during the season that began Oct. 1, 2018, was 129 percent greater than normal at almost 44 inches.

Smith said they are receiving a “record number of requests for help” for mosquito abatement. The Vector Control District closely monitors mosquito activity and tests mosquitoes and sentinel chickens for pathogens. Mosquitoes can transmit diseases including West Nile Virus, dog heartworm and malaria.

Now is the time to check for standing water to minimize mosquito production, the Vector Control advises. Look for such things as potted plant saucers, trash bins, tarp covers, and rain gutters for example, but don’t overlook objects like sculptures and lawn ornaments, which may have little depressions where water can collect and mosquitoes can breed. West Nile Virus can be deadly; the malady arrived in the west coast of America in 2002. The Vector Control District asks people to report dead birds – which can help them detect West Nile Virus activity – by calling 877-968-2473.

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