As of July 2018, brown marmorated stink bug (BMSB) has been recorded in 21 Washington state counties; with most along the I-5 corridor. If you see a BMSB, please send a photo, general location (inside or outside of house or car, backyard, park, etc.) and the address it was found to: tfrec.reportBMSB@wsu.edu
Brown marmorated stink bug (BMSB) is an invasive pentatomid from Asia that has spread to the US and Europe. In the US, it was first detected in Pennsylvania in 1996, and is now well established throughout the mid-Atlantic area, and north and south along the eastern seaboard. It is also established in the Great Lakes region and the Southeast. Spread to the west coast states began in the mid-2000s, and it has now been detected in wide geographic areas in California, Oregon and Washington. North American detections have been made in 43 states and 3 Canadian Provinces. Distribution and population density has been steadily increasing in Washington, with 21 counties now reporting infestation. Initially, BMSB was most numerous in the I-5 corridor and along the southern border, but detections have been made in many eastern interior counties. Of the major fruit production counties, only Grant and Adams have not yet reported any BMSB, although survey efforts are largely confined to homeowner reports. There are well established nuisance populations in the towns of Walla Walla and Yakima. In Oregon, crop damage to hazelnuts and tree fruits in the north Willamette valley of Oregon has been occurring for several years; in Washington, damage to vegetable crops in a diversified farm in Vancouver has been reported. Other reports of crop damage in commercial fields in Washington have been made, and detections in commercial operations are becoming more common.
While the host range of BMSB is extremely wide, tree fruits are considered to be one of the highest at-risk crops. BMSB is potentially more damaging than the native stink bugs because it has at least 2 generations/year (natives typically have only one), and both nymphs and adults can feed on fruit (natives damage fruit only in the adult stage).
The experience of fruit-growers in the mid-Atlantic area was that control of BMSB required applications of nonselective, broad-spectrum materials at frequent intervals; even with this level of pesticide input, fruit damage could still reach 20% in high pressure years. The use of these pesticides caused outbreaks of secondary pests in what had been a relatively stable IPM program, necessitating further controls for the secondary pests. Chemical control as a sole tactic has not been satisfactory, thus alternative management strategies must be sought.
An Asian parasitoid, Trissolcus japonicus (samurai wasp), is an effective egg parasitoid of BMSB in its native range. Foreign exploration for natural enemies in the late 2000s identified this species as a candidate for classical biological control, and it was brought to the US and placed in quarantine facilities to undergo rigorous testing on non-target species, where it remains at this time. A wild population was first discovered near Beltsville, MD in a 2014 survey, with later discoveries in nearby Virginia. In the fall of 2015, the discovery of a wild population in Vancouver, WA expanded the known range by 2,300 miles. The discovery of these wild populations has potentially sped up the timeline of implementing biological control. While this parasitoid will not eradicate BMSB, it may be extremely helpful in suppressing non-crop populations, by not allowing them to build to outbreak levels. Reducing the overwintering populations will facilitate any IPM practice employed for control of BMSB.
BMSB in Orchard Pest Management
For more information about BMSB, including host plants, life stages, life history, crop damage, monitoring, biological control, and management, please see the BMSB page on the Orchard Pest Management site.