Could a parasitic fly help solve P.E.I.'s growing Japanese beetle problem?

There could be a biological solution to P.E.I's growing Japanese beetle problem.

After years of work, researchers with Agriculture and Agri-Food Canada are zeroing in on a typeof fly that can literally take a bite out of the pest that is wreaking havoc on gardens across the country.

Christine Noronha, a P.E.I.-based research scientist with Agriculture and Agri-Food Canada, said the winsome fly (Istocheta aldrichi) lays its eggs on the beetles. Once the eggs hatch, the fly larvae eat the beetles from the inside, usually before the beetles can themselves lay eggs.

Populations of the parasitoid fly havealready been released in British Columbia and Ontario, whichare also dealing with a Japanese beetle problem, and Noronhasaid it isdoing itsjob there.

"It is keeping the population low," she said. "Biological controls never eliminate the population, but it is working."

The invasive Japanese beetle, orPopillia japonica, was first reported on the Island in 2009. Itspopulation has been growing ever since.

The beetle likes the Island's warm, moist conditions and its lack of natural predators, said Noronha. It lays its eggs in grassand goes on to attackabout 300 different plants, with a special affinity for roses, peaches and grapevines.

Right now, Noronha said the beetle is mostly a concern in people's gardens, but it could become an issue for farmers as the population spreads.

"They could become a problem in fields eventually if we don't do something," she said.

More research is needed before the parasitoid fly is introduced to Prince Edward Island, but Noronha said if everything goes well, that couldhappen next year.

In the meantime, there are some products Islanders can use to help deal with the problem.

Noronha said spraying your beds with beneficial nematodes which are microscopic worms that occur naturally in soil can help kill off beetle larva. The best time to do that is in the spring.

When the beetles reach adulthood, from about mid-July until mid-October, some gardeners suggest picking them off plants one by one and flicking them into a jar of hot, soapy water. You could alsocoverplants you want to protect with a light netting before you start to notice leaf damage.