Since its accidental importation from Asia to North America in the mid-1990’s, and the first positive identification in 2001, BMSB has begun seriously affecting urban areas and a range of vegetable, fruit and ornamental crops, particularly in the mid-Atlantic U.S. It was first detected in the western U.S. in Oregon in 2004, and there are currently established, reproductive populations in 6 California Counties: Butte, Los Angeles, Sacramento, Santa Clara, San Joaquin, Stanislaus and Sutter.
Although specimens have been intercepted in Napa County, there is currently no known reproducing population. Because BMSB has established populations in nearby counties, there is a high risk of introduction; it has a wide host range (upwards of 60 plant species that includes grape) and a propensity for overwintering in houses. If introduced to Napa County it could be a pest of concern for residents and growers, and therefore, the Napa County Winegrape Pest & Disease Control District has begun funding research and management efforts and BSMB has also been added to the Sentinel Trapping Program.
There have been no positive finds in Napa county since the start of BMSB trapping last year.