Warm temperatures a boon for stink bugs
VANCOUVER, Wash. — On a hot June day, Joe Beaudoin ducked into the shade of his orchard to check for peaches with shallow dimples — the telltale signs left by the brown marmorated stink bug.
This invader from Asia has a formidable appetite for the berries, tree fruits and vegetables that Beaudoin grows on his 80-acre farm.
This spring, even before the trees sprouted all their leaves, the bug already had begun to pierce the tiny peaches to suck out juice.
Beaudoin expects more crop losses in what is shaping up to be a big year for the stink bugs.
The same mild temperatures that sabotaged the region's snowpack were a boon to these bugs, reducing their mortality during the coldest months and generating plenty of early spring bounty for forage.
And as climate change unfolds in an increasingly interconnected world, the warmer weather forecast for the decades ahead could make the Northwest a more welcoming region for some of the pests that arrive from elsewhere.
The stink bugs get their name from the scent they release, which some describe as akin to a musky cilantro. They are well-entrenched in the Portland-Vancouver area, and — to a lesser extent — in Seattle. In both cities, some urban homeowners have been beset by infestations as the bugs find indoor spaces to overwinter.
These insects have also spread south through the Willamette Valley, where Oregon State University researchers have purposefully mixed in the stink bugs with the grape crush to try to figure out how many insects it takes to mess with the taste of the region's fabled Pinot Noir.
"We should be able to keep them out of the wine, but even if they get in, we're looking at some processing steps so that you can get rid of the flavor," said Elizabeth Tomasino, an Oregon State University researcher.
So far, in the orchard country of Central Washington, only a few stink bugs have been found in nearby residential areas, and there are still plenty of questions about how well they can adapt to such an arid area.
But these farmers are on alert.
Spurred by the government phaseout of some insecticides, they have under taken a major effort to develop alternative pest controls. If the population booms in their orchards, they would likely dramatically step up their spraying.
The weird warm weather has also boosted the populations of another recent Asian invader: a tiny fly called the spotted winged drosophila that lays its eggs in the fruit of cherries, berries and other crops. This year, Beaudoin says he had to spray his strawberries, marionberries and blackberries once a week to keep these fruit flies at bay.
The stink bugs attack a broader range of crops — including the apples that are Washington's most valuable harvest.
Researchers are scrambling to figure out not only what are the most effective insecticides to use on the stink bugs, but also when best to apply them. So far, for Beaudoin, that's still uncertain.
"This is all new. For timing, it's just going to be a guess," Beaudoin said.
As the bugs spread from the Portland area in search of food, the vineyards of Western Oregon represent close-by targets. So far, they have not shown up on grapes in sufficient quantities to pose a problem for winemaking, according to Tomasino, the OSU researcher. If they did, blowers used during sorting could hopefully keep them out of the crush.