Issue link: https://read.dmtmag.com/i/263110
GOOD FRUIT GROWER MARCH 1, 2014 25 "In 2013, it got a lot worse, and we're seeing more established populations, both in Oregon and Washington," Wiman said. The pest is confi rmed in Walla Walla, Washington, and in drier locations of Oregon, including The Dalles, La Grande, and Hermiston. Wiman believes it's very likely to be established in the Tri-Cities area of Washington. California officials began looking for brown marmorated stinkbug last year and found a signifi cant population located in Sacramento. A detection in Hermiston is the fi rst indication of its movement into the Columbia Basin, a desert climate with irrigated agriculture, he noted. That's signifi cant because past detections on the East Coast and in Oregon's Willamette Valley were near mixed wood forests, ripar- ian zones, and habitat similar to the stinkbug's native environment in Asia. Urban risk factor Last year saw the first documented report of economic damage to a commercial grower. A Vancouver, Washington, grower farming 80 acres of tree fruit and vegetables had signifi cant damage in his Asian pears, Granny Smith apples, and several vegetable crops. "The Vancouver farm is an extremely urban farm," Wiman said. "The urban risk factor has a lot to do with that farmer having economic damage." Most farms in the Willamette Valley where the pest has been found are also near urban areas, though not as close as the Vancouver farm. "Humans are a big factor in the stinkbug's dispersal," he said, adding that the stinkbug hitchhikes in moving vans, recreational vehicles, lumber shipments, freight trains, and ships. Using fl ight mills (a device attached to bugs allowing them to fl y in continual circles), OSU researchers found that the brown marmorated stinkbug is a good fl ier. Most can travel about 15 miles within a 24-hour period. "A few fl ew 50 miles in a 24-hour period, so they don't need a lot of assistance from us," Wiman said. The pest attacks a wide range of crops, damaging fruit and vegetables with its sucking mouthparts that secrete saliva while the insect sucks up the plant's juices. Fruit fl esh is discolored; dimpling and bruising can also occur. Wiman found it has a similar appetite on the West Coast as in the Mid-Atlantic region, where it has spread since the fi rst U.S. detection in Pennsylvania in 1996. In the Willamette Valley, stinkbug damage has been observed on apples, Asian pears, cane berries, blueberries, and hazelnuts. Though tree fruits are not a big crop in the Willamette Valley, hazelnuts are. Oregon produces 99 percent of the nation's hazelnut crop. "The stinkbug has no problem feeding through the shell of the nut and reaching the kernel," he said. Crops like wine grapes and mechanically harvested bush and cane berries also face potential contamination issues from the stinkbug's odor, a smell that some liken to cilantro. OSU's food science department studied contamination in Pinot Noir wines. When given three blind samples of Pinot Noir (one spiked with brown marmorated stinkbug), tasters could easily pick out the spiked sample. "It wasn't that it tasted bad," Wiman said, "but certain wine fl avors were masked by chemical reactions from the stinkbug." One of the problems in managing brown marmorated stinkbug is that it has a long list of host plants in the United States. Two of the stinkbug's favorites—tree of heaven and Himalayan blackberry—are commonly found on both sides of the Cascade Mountains in Washington and Oregon. Tree of heaven, in the Pacifi c Northwest since early railroad days, is found alongside train tracks and often is the only green plant around. Himalayan blackberry is loved by both the stinkbug and spotted wing drosophila, another recently arrived pest gaining a foothold in U.S. fruit-producing regions. The invasive blackberry plant grows like a weed in many areas when left unchecked. Other common plants in Northwest forests that Wiman has found serving as hosts include dogwood trees, several maple species, and English holly. With the recent discovery of brown marmorated stinkbug in the Columbia Basin, Wiman said it's an open question about what the pest will do in a dry environment. "It remains to be seen how the pest will do in our dry deserts, with its limited amount of vegetation and number of alternate hosts, massive farms, and few people." But if it's not in your area yet, know that it's likely coming. • can "A few fl ew don't need a Wiman said. spike said, "but certain w reactions from the stinkbu nia Hood ver es Wasco Klickitat Yakima Chelan Gilliam Benton Umatilla Walla Walla Union Established Detected Northwest Spread 2013 BSMB fi ndings, courtesy Nik Wiman, OSU. To learn more, visit www.stopbmsb.com. R esearch to fi nd a natural enemy that suppresses the brown marmorated stinkbug is show- ing promise, according to Oregon State University entomologists. Biological control research led by the U.S. Department of Agriculture, in conjunction with several state agriculture departments and state universities, is looking good, said Dr. Nik Wiman, OSU postdoctoral entomologist. USDA is using Oregon quaran- tine facilities to screen several par- asitoid wasps that are being studied across the country under expedited review, Wiman said. The parasitic wasp Trissolcus japonicus from Asia is a promising candidate, although more study is needed. The wasp lays eggs in the stinkbug's eggs, which prevent the pest from developing. Researchers must fi rst make sure any newly introduced insect will not have a negative impact on existing environments and species. Before any release, the new wasp must be known to be host specifi c, targeting brown marmorated stinkbug and not other stinkbug species. Some stinkbug species are beneficial predators. Biological control can take years to become established because the natural enemy has to increase to large enough populations that it can suppress the targeted pest. —M. Hansen Joe Beaudoin of Joe's Place Farms, an 80-acre u-pick farm market in Vancouver, Washington, holds a Cameo apple damaged by brown marmorated stinkbugs. He estimated that he lost most of his Granny Smith apples (about 3,000 pounds) to stinkbug damage. A female Trissolcus japonicus parasitoid wasp emerging from parasitized Halyomorpha halys eggs at the USDA-APHIS Quarantine Facility, Corvallis, Oregon. PHOTO COURTESY PETER SHEARER, OREGON STATE UNIVERSITY PROGRESS ON biological control PHOTO ILLUSTRATION: COURTESY CHRISTOPHER HEDSTROM, OREGON STATE UNIVERSITY