British Columbia

Researchers hope tiny 'samurai wasp' may stop invasive stink bugs eating through the Okanagan

Stink bugs are munching their way through the Okanagan Valley and researchers are hoping a tiny wasp can help contain the pests before they hit B.C.’s orchards en masse.

Brown marmorated stink bug a destructive agricultural pest that can cause millions in dollars of damage

The brown marmorated stink bug is an invasive pest that attacks tree fruits, berries and ornamental plants. (Matt Rourke/Associated Press)

Stink bugs are munching their way through the Okanagan Valley and researchers are hoping a tiny wasp can help contain the pests before they hit B.C.'s orchards en masse.

Last summer, more than a thousand brown marmorated stink bugs were counted in Kelowna's downtown core. A provincial study was launched to research the invasive species.

"We started trapping them last year," said Susanna Acheampong, an entomologist with the Ministry of Agriculture.

"It seems that they are still staying in the downtown core …  But eventually, they will move out."

The brown marmorated stink bug is a destructive agricultural pest that attacks tree fruits, berries, grapes, vegetables, corn and ornamental plants.

Costly problem

For now, Acheampong said, they're finding enough plant hosts in the downtown core but it's only a matter of time before they start damaging food sources.

"They stay in the residential areas for a few years and then they become a pest in commercial settings," Acheampong said.

And once they do, it can be a costly problem.

The species caused $37 million in damage to the mid-Atlantic U.S. apple industry in 2010, for example.

The brown marmorated stink bug can be extremely destructive to crops. (Ontario Ministry of Agriculture)

Biological control agents

That's why researchers are desperate to find a way to contain the pests as soon as possible and turning to biological control agents as a possibility.

"In Asia, they have this tiny wasp that's the size of a sesame seed -— they are called samurai wasps," Acheampong said.

"The wasp will attack the eggs of marmorated stink bugs."

Brown marmorated stink bugs can be identified by their bent antenna and the white stripes on their legs and antenna. (Wikimedia Commons)

The wasps, though not native to North America, have been found in parts of the U.S. like Washington state and parts of Maryland.

Acheampong's research is looking at whether this species is also present in Canada and evaluating the impacts of introducing it as a biological control agent.

The stink bug itself is a native pest of Asia and was first identified in North America in Pennsylvania in 2001, according to the B.C. Ministry of Agriculture.

A brown marmorated stink bug hatched egg mass. Researchers say that samurai wasps attack the eggs. (Ontario Ministry of Agriculture)

While the research is underway, Acheampong is urging residents to kill any stink bugs they find by either vacuuming them up or dropping them in soapy water to drown.

The stink bug is distinguishable from other bugs because of its size and the white stripes on its antennae.

"People don't like killing bugs but they can be quite the nuisance so anything that you can do to reduce the population will really help," she said.  

With files from Daybreak South.

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