Cold, wet spring means far fewer yellow jackets, wasps

After a long, harsh winter, spring brought little comfort to man or beast in the Pacific Northwest. For proof, look no further than the regional wasp population.

Wasps are a common sight during backyard barbecues and among gardens and trash cans in July and August. But across Washington, yellow jacket and paper wasp populations are down far below normal for this time of year, Washington State University entomologist Richard Zack said. The soggy, cold spring is largely to blame — or maybe thank.

In a queen wasp’s life cycle, she will hibernate through the winter then emerge in the spring to build a new colony. At first she does the hunting to feed her few larvae until they’re old enough to do the work and she can stay behind to lay more eggs. For that to work well, the weather needs to be at least fairly dry.

“When the spring occurs, they’re very vulnerable to the conditions,” Zack said. “If they find a place to start a nest but the weather is rainy and cold and they can’t go find prey, then they can’t survive. So the nest never really gets started, and for every nest that doesn’t get started, that’s a nest that won’t be there when it is nice.”

With mid-summer upon us, outdoors lovers and picnic planners can relax a bit more knowing that there are fewer of the nuisance insects flying around. Because the predator’s population is down this year, there will likely be more insects of other varieties flying around.

“For every colony of say, yellow jackets, that’s not there, that could be 500, 600 to 1,000 wasps not picking up caterpillars,” and other bugs, Zack said. “But will you notice in your backyard garden? I doubt it.”

Yellow jackets and paper wasps are the most common types of wasps in Washington. Unlike honey and bumble bees, which rely on flowers for food and sting only once before they die, wasps eat everything from other insects to barbecued ribs and can sting numerous times when they’re defending themselves or their nests.

Although the resident populations took a hit, Zack said there’s little reason to fear for the bug’s future. Zack said plenty of queens have likely survived to establish nests. And so long as they’re in a place where they’re not bothering anyone, they can be thought of as a beneficial insect.