Issue link: https://read.dmtmag.com/i/603228
www.goodfruit.com Good Fruit Grower DECEMBER 2015 63 He noted that researchers recently confi rmed that the number of generations varies by region. Three years of study identifi ed two complete generations in Oregon's Hood River compared to only one generation on the East Coast. "Even though we are a more northern latitude than Allentown, Pennsylvania, where the pest was fi rst established and one generation identifi ed, our warmer summers are resulting in an extra generation," he said. A high priority of the project is to develop effective bio- logical control that uses natural predators. Mid-Atlantic tree fruit growers impacted by brown marmorated stink- bug have learned that chemical control is diffi cult and can turn IPM programs upside down. Control is chal- lenging because stinkbug can overwinter in protected places and move in and out of orchards. Many entomologists, including Shearer, believe biological control will be the saving grace for growers in the future. Researchers are studying several parasitoid wasps, some collected in Asia. It was earlier reported that a promising imported species—Trissolcus japonicus— wouldn't make it out of quarantine because it was found to also go after native stinkbug species. But recently, T. japonicus have been found in the wild near brown mar- morated stinkbug populations on both East and West coasts, according to Shearer, indicating that the bene- fi cial wasp is already here. Washington State University in October publicized the discovery of the wasp in the leaves of a maple tree in Vancouver, Washington, fi rst on August 14 and again on September 23. (Read about that discovery at www.goodfruit.com.) Be alert Dr. Betsy Beers, WSU entomologist, advises Northwest growers to be on the lookout for the stinkbug. "It's not time for Northwest growers to hit the panic button yet, but growers need to be on the lookout for the pest," she said. Beers is collaborating with Shearer and others on the national research project and was part of a team that visited Walla Walla in early fall to collect brown marmorated stinkbug for research purposes and see fi rsthand its habits and host preferences. The Walla Walla stinkbug fi nds in two vineyards were not surprising because of their proximity to the city, she noted. "We had a pretty sure idea that it was already established in the city of Walla Walla from previous reports. We had to look really hard to fi nd the one or two stinkbugs in the two vineyards we visited, but there were plenty of stinkbugs in city trees and in trees near one of the vineyards." The stinkbugs in commercial pear orchards of the Mid-Columbia region were caught in traps and also found through scouting. Shearer reported that some fruit damage was evident, though not at economic levels, but it was unclear if the damage came from brown mar- morated stinkbug or native stinkbug species. Beers urges Northwest growers east of the Cascade Mountains to bring suspected brown marmorated stinkbugs into their local extension offi ce or extension research center for identifi cation. The pest is already established west of the Cascade Mountains. "We want to monitor its spread and range of expan- sion," she said. Researchers are most interested in learn- ing if stinkbug is moving into agricultural regions, such as the Yakima Valley, Columbia Basin, and Wenatchee. • PRESENTATION Peter Shearer will give a presentation "Current Status of the Brown Marmorated Stinkbug in the Pacifi c Northwest" during a pest and disease session at the Washington State Tree Fruit Association's annual meeting in Yakima. Adult brown marmorated stink bugs are caught and put into containers.