Invasive fruit fly worries Maritime farmers

Maritime scientists are studying the population of an invasive vinegar fly that has turned up in the region and could destroy fruit crops.

The spotted wing drosophila is an invasive alien vinegar fly, native to Asia, and is closely related to what is commonly known as a fruit fly.

But the insect, which has turned up in all three Maritime provinces, inflicted $2.2 million in damage to the British Columbia cherry industry in 2010.

The arrival of the flies is concerning many New Brunswick fruit growers.

Madeleine Céré, the owner of a u-pick berry business in Pré d'en Haut, has bug traps throughout her southeastern New Brunswick property.

She said she first heard about the spotted wing drosophila last summer.

"Last year, we trapped some by the end of August, early September, yes. But this year, as far as I know we didn't trap any yet, she said.

Céré said she's concerned about the potential impact of the insects, but said she understands that pests are a part of food production.

The spotted wing drosophilia will attack fruit such as raspberry, blackberry, blueberry, strawberry, cherry, plum, peach, nectarine, and sometimes grape.

The insect can be very destructive, ripping into ripe fruit and laying eggs under the skin.  

The first fly was identified in North America in 2008. A year later, the first insect was spotted in Canada in Kelowna, B.C.

At the time, researchers didn’t know if the species would be able survive a Canadian winter, but they have returned every year and spread across the country.

7,143 insects trapped in 2012

Stephanie Compton, a horticulturalist with the Atlantic Canadian Organic Regional network, said the adult flies have been found in all three Maritime provinces.

She said scientists want to see how large the populations of flies are and if they can survive in a Maritime winter.

"It's not a native pest here, we don't know how it will over-winter we don't know how the populations will expand in our climate, we don't know enough about it," she said.

The research is being conducted by Really Local Harvest and is being funded through the Canada-New Brunswick Agriculture Futures Initiative.

A 2012 research project set traps at 20 sites around the province and 19 found the pests. It monitored blackberry, blueberry, cherry, cranberry, honeysuckle, grape, plum, raspberry, sea-buckthorn and strawberry crops.

One insect was trapped in July 2012, but those numbers grew to 637 in August and 7,143 in September.

Chris Maund, an entomologist with the Department of Agriculture, Aquaculture and Fisheries, said 75 traps have been set up this year.

So far, he said none of the invasive fruit flies have been trapped. So it is unclear if they survived the winter.

Farmers are being asked to be on the lookout for the destructive fruit fly.

Compton said not enough is known about how the spotted wing drosophila could affect the fruit industry.

"We're asking farmers to educate themselves, to learn how to identify the fly," she said.

"We're teaching them how to make traps and how to monitor for it and then when we know what the spread of the fly looks like, we can come up with a management plan."