Good Fruit Grower

March 15

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24 MARCH 15, 2015 GOOD FRUIT GROWER www.goodfruit.com FEW BEES Grapes P reliminary research shows that few bee pollinators are found in wine or juice grape vineyards of eastern Washington, an important finding if neonicotinoid pesticides are further regulated. Provado (imidacloprid), a key insecticide used by Washington grape growers, is in the neonicotinoid class. The plight of the honeybee has caught the attention of folks worldwide. Although research has implicated neonicotinoids as a factor in the loss of honeybees, there are multiple reasons for declining bee populations. Bees live in a toxic world and face many stresses, including loss of habitat, lack of genetic diversity, pesticides used to control Varroa mite, and more. "Environmental groups are using the cause of bee conservation and safety as a reason to fur- ther regulate pesticides, such as neonicotinoid pesticides," said Dr. Doug Walsh, integrated pest management specialist for Washington State University. Walsh and a team of WSU researchers initiated a bee survey last summer in wine and juice grape vineyards. Grapes are wind-pollinated and don't need bees for pollination. However, documen- tation of bee populations in vineyards will be valuable information if restrictions are placed on neonicotinoids in the future, he explained. "We really don't see a lot of bees in our vine- yards in eastern Washington," Walsh said during a meeting of the Washington State Grape Society. Additionally, because most wine grape vineyards are drip irrigated, cover crops, including flowering ones that could attract bees, are rarely grown in wine grapes. "But we need to prove that we have few bees in our vineyards in case Provado comes under fire in the future." Imidacloprid has become an important pesti- cide used by growers to control grape mealybug, scale, and leafhoppers, all of which are either known or suspected vectors of grapevine viruses. Imidacloprid is a systemic insecticide commonly applied through the drip system. Party cups WSU graduate student Courtney Grula sur- veyed hops, grapes, and blueberries in the search for bee pollinators. She used white, blue, and yel- low plastic party cups as "bee bowls" to quantify and qualify bee populations in eight vineyards (four wine grape and four juice grape), four hop fields, and four organic blueberry fields. Grape pest practices in Washington aren't harming bees. by Melissa Hansen in vineyards COURTESY DOUG WALSH Bee bowls were placed near less-disturbed areas as part of grape bee survey work conducted by Washington State University scientists. DAVID CAPPAERT / MICHIGAN STATE UNIVERSITY Shiny, green metallic sweat bees (Agapostemon) were commonly caught, though not frequently in vineyards. COURTESY DOUG WALSH An example of an alkali bee of the Halictidae family, the most prevalent of all bee species caught in a Washington State University bee survey last year, though few were found in vineyards.

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