Invasive stink bug makes province's apple growers nervous

An invasive insect is feeding its way across Canada and could soon be making an appearance in New Brunswick, which has apple growers fearing for their crops.

The brown marmorated stink bug has been feasting on fruit crops in Quebec, Ontario and British Columbia. Now, researchers expect the species to move into neighbouring provinces.

The bug, which originates in Asia, has "piercing, sucking mouth parts," similar to a straw, which allows it to pierce the skin of a fruit and turn the flesh into a smoothie it can suck back up, said entomologist Suzanne Blatt of Agriculture and Agri-food Canada. 

Scientists and agriculture experts have been on the lookout for the invasive species since 2012.

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"Our climate's changing a bit, so we're getting insects that are normally more south coming north," said Chuck Everett of Everett Family Orchard in Island View, just outside Fredericton.  

Everett said the movement of the stink bug is being monitored carefully, and apple growers are hopeful it won't be devouring their apples anytime soon.  

His family farm has been busy taking precautionary measures, short of spraying, to prevent the insects from getting into crops.

"We keep our orchard very neat … you have to come up with every technique that doesn't lean to product application."

The stink bug feeds on a wide variety of crops, including tomatoes, peaches, corn, plums, sweet cherries, grapes, blueberries and raspberries. It can get into houses and tries to keep predators away with an unpleasant smell.

The consumer doesn't want an apple or a peach that has that sunken, bruised look to it.- Suzanne Blatt, research entomologist

Blatt said the bug doesn't rip open the fruit's skin, and all of the damage occurs under the skin's surface, she said.

Afterward, the skin will sink, making the fruit appear bruised. The fruit is still edible, Blatt said, but the area where the insect has injected into the fruit will be a bit spongier and will lack the typical firmness. 

The fruit is hard to sell because it will look like it's rotting. The impact is even greater with smaller fruit.

"The consumer doesn't want an apple or a peach that has that sunken, bruised look to it," she said. 

"Your whole sink would look like a bad case of acne."

Blatt said growers would have to be invaded by a lot of stink bugs to lose an entire crop. But even a threat to 20 to 30 per cent of crops would be serious.

New Brunswick will likely see it

The insect has been travelling to Canada from the United States, "hitchhiking on a long-haul truck or coming home with a tourist" from infected areas such as Pennsylvania or Kentucky.

The insect travelled into the States in 1999 and took about 10 years to adapt. It has spread across all of the States with the exception of Alaska and Hawaii, she said.

"We're expecting it to spread from those locations into the neighbouring provinces," said Blatt. "New Brunswick will likely see it." 

In the U.S., harsh sprays and pesticides have been used to prevent the species from showing up, Blatt said.

"Canada doesn't have that toolkit," she said.

Instead, researchers are looking for biological control methods to prevent the insect from spreading once it reaches the Atlantic provinces.

The region may have the advantage now, since the brown marmorated stink bug thrives in extreme heat and affected by the length of day, Blatt said. In Canada, she said, days are already getting shorter in July, and the insects shut down their reproduction and move into wintering mode.

"It has the ability to damage a lot of [crops]," she said.