Manitoba warns fruit growers about invasive pest

Whether you own a farm or have a backyard berry patch, the province is warning fruit growers about a tiny pest causing massive problems: the spotted wing drosophila (SWD).

The SWD is an invasive fruit fly or vinegar fly that has found its way into Manitoba crops, specifically strawberries, Saskatoon berries, raspberries, sour cherries and cherry plums.

“Spotted wing drosophila has been with us in Manitoba for over 10 years now,” said Philip Ronald, who owns and operates Riverbend Orchards in Portage la Prairie, Man. “It’s something we’ve learned to live with.”

The pesky critter is an invasive species from East Asia. According to experts, this year’s warm winter and soggy spring and summer created ideal conditions for the SWD to populate. But unlike the average fruit fly, the SWD can do more damage by penetrating fruits before they ripen.

“These get in really early and so their larvae start developing inside the fruit before it’s time to harvest them,” said Jason Gibbs, an associate professor in the department of entomology at the University of Manitoba.

The spotted wing drosophila is an invasive fruit fly or vinegar fly that has found its way into Manitoba crops, specifically strawberries, Saskatoon berries, raspberries, sour cherries and cherry plums. (Alexandra Holyk/CTV News Winnipeg).

Once the insect breaks the skin, it can be easy to pick out an infected plant. Some signs to look out for include: “Overall discolouration – it’s kind of a darker colour,” Ronald pointed out. “You’ll also notice that the shape of the cherry is affected as well.”

And if you accidentally bite into a bugged cherry or berry, it may just leave a bad taste in your mouth.

“It won’t make you sick,” said Manitoba Agriculture fruit crop specialist Anthony Mintenko. “It’s safe to eat. You probably won’t, just because it’d be so soft.”

While there are ways to mitigate the pests, some farms are struggling to keep up.

“When we do chemical treatments, it’s always with the view to disable the egg-laying process,” Ronald said. “And it works very well that way, but you can never get 100 per cent control.”

It’s forced Riverbend Orchards to cut back costs for u-pickers.

“We told them we … have seen a little bit of the insect here, probably two or three per cent, and we also discounted the price for that reason,” said Ronald.

Experts recommend home growers check their berries for bugs and any blemishes. They also advise people to pick their fruit fast and put it in the fridge, since the cool temperature will kill off any pests.

Another method is the “saltwater test,” which involves soaking the fruit in saltwater for some time, to allow any larvae to leave the berries before they’re rinsed off and consumed.