Issue link: http://read.dmtmag.com/i/643470
30 MARCH 1, 2016 Good Fruit Grower www.goodfruit.com Y ou've heard of spotted wing drosophila and the devas- tation it can cause to thin- skinned fruit, and you've seen the predictions that this pest may soon be coming to your area. As a cherry grower, you do the prudent thing: set out traps and monitor your orchard for the tiny flies so you can mount a timely defense, if necessary. As the sea- son progresses, the traps remain empty, your fruit starts to color, and you think it's clear sailing. Then one of your traps catches a few flies. You quickly check the cherries and find they're already infested. What went wrong? "If you're only trapping your own orchard, you might be missing the big picture," said David Haviland, entomol- ogy adviser for University of California Cooperative Extension in Kern County. The "big picture" is that the flies were living and reproducing happily nearby in other plants, their numbers were building, and when your cherries devel- oped to the stage that attracts SWD, the insects made a beeline for your orchard and descended en masse on your fruit. The trigger for SWD is the assemblage of volatile chemicals that the cherries release as they mature, he said. "As soon as the flies can smell those volatiles, they will start to move into the cherry orchard." To truly stay on top of SWD, growers need to think outside the box, and in this case, that means outside the orchard in noncrop host plants, Haviland said. "The recommendation is to make sure you're trapping in any area surrounding the orchard that might be harboring spotted wing drosophila." Searching for SPOTTED WING DROSOPHILA Experts say growers should look beyond orchards for SWD. by Leslie Mertz "If you're only trapping your own orchard, you might be missing the big picture." —David Haviland Pest Management A male spotted wing drosophila fly (Drosophila suzukii). PHOTO ILLUSTRATION COURTESY MARTIN COOPER Continued on page 32