Tender fruit pest arrives in Ontario

Tuesday, April 12, 2011

Top photo: a female (L) and male (R) spotted wing drosophila. The insects are 2-3 mm in length.

Lower photo: the ovipositor of a female spotted wing drosophila

Photos contributed by H. Fraser, Ontario Ministry of Agriculture, Food and Rural Affairs

by SUSAN MANN

A new tender fruit pest from Asia has arrived in Ontario but growers shouldn’t panic as spotted wing drosophila is manageable, says an agriculture ministry spokesperson.

Hannah Fraser, entomology program lead for horticulture, says important management tools for growers to control the pest include awareness, monitoring, sanitation and the use of registered insecticides during a crop’s risk period.

She says the spotted wing drosophila attacks thin-skinned fruit and berries as they’re starting to ripen (raspberries, blackberries, blueberries strawberries, cherries, plums peaches, nectarines and occasionally table grapes) by sawing open the skin with a device on the insect’s back end. The female lays eggs under the fruit’s skin; hatched larvae feeds on the fruit causing it to rapidly deteriorate. It’s a big problem on the west coast of the United States and Canada.

It was first detected in monitoring traps in the Niagara area in November by the provincial agriculture ministry and the Canadian Food Inspection Agency. This year the provincial ministry will do more surveys for the pest.

“It’s believed there are parts of Ontario that are at risk for this insect becoming established and overwintering,” she says. But currently there “are a lot of unknowns” about the insect in Ontario.

Fraser says the agriculture ministry hasn’t had any growers report damage from last year. The ministry has been publicizing the find since last fall and plans to provide information to growers throughout this growing season.

The tiny spotted wing drosophila is active from the beginning of the growing season to harvest, she says.

A special task force will try to develop a working group to research the insect as well as management strategies, she says.

Last year British Columbia secured four different insecticides for use against pest and all provinces are working together to get those registered products for growers this year. BF