The brown marmorated stink bug (BMSB) is a new invasive insect that was first found in the U.S. in 1998 and in Iowa in 2011. Additional reports by homeowners have documented BMSB in 19 counties in Iowa. See the map below.
The BMSB looks similar to other brown-colored stink bugs but is distinguished by the mottled brownish gray color and the alternating light and dark bands on the antennae. See photo below.
BMSB is a serious plant pest that feeds on a wide variety of fruits, vegetables, field crops, trees and shrubs. The bugs have piercing-sucking mouthparts and puncture the skin of developing fruits and vegetables, stunting and deforming growth and making them unsalable and unusable. In the fall of the year BMSB becomes a household accidental invader and wanders indoors (similar to boxelder bugs and multicolored Asian lady beetles, only larger, smellier and worse!)
Crop damage by BMSB has not been reported in Iowa. Reports are based on observations on or in households.
We are continuing to track the distribution of BMSB in Iowa and would appreciate your reports. Submit suspicious stink bugs to your local county extension office or the ISU Plant & Insect Diagnostic Clinic. Reports can be made by emailing digital images to the Clinic at firstname.lastname@example.org. To distinguish BMSB from other brown stink bugs and similar insects, send specimens or a clear, close-up digital image to confirm the presence of BMSB in a new county.