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Malathion formulations receive emergency use for SWD

July 3, 2012, Dorchester, Ont – Two formulations of Malathion insecticide have received emergency use label registrations in support of control of Spotted Wing Drosophila (Drosophila suzukii) on sweet cherries, stone fruit and berries.

The two formulations are Malathion 85E for use on stone fruit and berries and Malathion 25W, for use on sweet cherries. The labels are in effect until November 30, 2012. Provinces covered under the recently approved labels include British Columbia and Ontario, for both Malathion 85E and Malathion 25W, as well as Alberta, Quebec, Nova Scotia and Prince Edward Island for Malathion 85E.

Malathion is a Group 1B insecticide that has been registered for use in different capacities in Canada since 1953.

Under the terms of the label, Malathion 85E may be used on a broad range of stone fruits including apricots, sweet and sour cherries, nectarines, peaches, plums, prune plums, strawberries, blueberries, raspberries, currants, gooseberries, blackberries and grapes. It should be applied using conventional ground application equipment at rates that vary between 610 to 1000 ml per 1000 L of water depending on the crop. Timing of applications, up to a maximum of two, should be based on the presence of adult flies. The interval between applications is seven to 14 days.

Malathion 25W, the wettable powder formulation, is approved for use on sweet cherries. It should be applied using conventional ground application equipment at a rate of 2.5 to 3.75 kg per 1000 L of water. Timing of applications, up to a maximum of three, should be based on the presence of adult flies. The interval between applications is seven to 14 days.

Janet Porchak, national marketing manager with UAP Canada Inc., distributor of Malathion 25W and Malathion 85E insecticide in Canada, says the Spotted Wing Drosophila is native to southeast Asia and prefers relatively warm temperatures (i.e. in the 20 to 30 C range).

“Unlike other fruit flies which tend to focus on overripe or decaying fruit, the female Spotted Wing Drosophila regularly lays eggs inside mature fruit prior to harvest,” Porchak says. “For best results the product should be applied when the temperature is 20 C or higher”.

Porchak also notes that Malathion insecticide should be used as part of an Integrated Pest Management program and in rotation with other insect management products as part of an effective resistance management strategy.