Along with freshwater mussels, knapweed and others, there’s a new invasive species starting to make its way into the Okanagan
Stink bugs are nothing new to the region. They are a native species, like the Western Conifer stink bug, but sightings of the brown marmorated stink bug is causing concern, especially for farmers.
Unlike most pests that confine themselves to one or two plants, this stink bug has more than 100 hosts, according to Dr. Susanna Acheampong, an entomologist with the B.C. Ministry of Agriculture.
“They will eat anything,” said Acheampong. That includes apples, peaches, even grapes, where stink bugs would not only damage the fruit, but ruin a crush if they get caught up in the process.
Like other stink bugs, this species releases noxious chemicals when threatened. But they also damage the fruit badly as they feed.
“The mouth part is like a needle, so they will pierce into the fruit and suck the juices. Their saliva is toxic, so you have some breakdown around where they are feeding,” said Acheampong. That makes the fruit unmarketable.
A number of the stink bugs have been found in Penticton, all along the Okanagan River Channel. The first four were found in May by an entomologist trapping beetles.
Acheampong said that is when they went to work to see how many there were.
“We searched and beat the bushes along the channel. We found them on chokecherries, we found five more immature in August. Then we found two more in one of the traps in October,” she said.
A dozen of the invaders might not seem like a lot, but Acheampong said this is how the infestation begins, with a small number coming into an area, probably hitchhiking on a vehicle. A single female can lay 200 eggs, and with no natural predators, the numbers begin to grow.
Fred Steele, a fruit grower and president of the B.C. Fruit Growers Association, said new pests are starting to show up more often.
“To me, all of these pests are not if, they’re when,” said Steele. “We used to have a new pest every five to 10 years, we are now getting them every three to five years.”
Steele points out that work is being done, not just on the brown marmorated stink bug, but all pests, noting how effective the sterile insect release program has been in reducing the codling moth, and work being done on an integrated pest management program.
“I am concerned. You’d have to be nuts if you weren’t. This pest is a serious pest,” said Steele, noting that the tree fruit industry has been around for 128 years. “We’re not going anywhere, this is just one more issue.
“The cycle of pests is going to become much more prevalent, because the world is getting smaller,” he said.
Acheampong said people are unlikely to spot any of the stink bugs at this time of year, with the bug going into its winter behaviour, looking for warm, enclosed spaces where a number of them will congregate.
It’s likely to be homeowners that will spot them now, she said. While the Okanagan River Channel is the only place the stink bugs have been spotted, a broad search program to determine the extent of their spread has yet to be done.
“That’s why we are asking people to help us,” said Acheampong. “If people find anything, they should send it to us.”
They can be confused, though, for the local species.
“We have green stink bugs, we have the brown ones, but the brown marmorated stink bug are bigger,” said Acheampong. She describes them as shield shaped, with distinctive white markings on the antennae.
“This is the time people will see the stink bugs in their homes as the bugs gather in colonies to overwinter in dark corners.”
Acheampong asks that the public send pictures or samples of suspect stinkbugs to herself. She can be contacted at Susanna.Acheampong@gov.bc.ca.
More information about the brown marmorated stink bug is available by clicking this link.