Homegrown: Invasive species alert

I thought Japanese beetles and the forthcoming emerald ash borer were bad enough.

Now Iowans need to be on the lookout for another invasive species: the brown marmorated stink bug.

Laura Jesse of Iowa State University provided photos of the newcomer – which has not yet been detected in Iowa – and two common bugs with which the bug might be confused.

Laura said there are more than 200 species of stink bugs in the United States; she wasn't sure how many of those are in Iowa.

But this latest type is especially damaging.

Here is more from Laura about this new invader:

The brown marmorated stink bug (BMSB), Halyomorpha halys is an introduced, invasive insect new to North America. It was first identified in fall 2001 in Allentown, PA; though unconfirmed reports go back as far as 1996.  The accidental introduction was possibly via shipping containers from Asia. The BMSB has been reported in several mid-Atlantic states, Oregon and California. To date, no one has reported this insect in Iowa. The closest documented infestations are in Chicago and Kentucky.

We are anxious to know when this insect arrives in Iowa. If you find a stink bug that emits a bad odor or is unfamiliar to you in your home, please contact the ISU Plant and Insect Diagnostic Clinic or your local Extension office.

BMSB feeds on sap from a long list of host plants including many fruits, vegetables, field crops, shade trees and other woody ornamentals. In addition to the considerable damage done to crops, gardens and landscapes, the adults have the disturbing habit of migrating to house and other buildings in the fall to overwinter. Homeowners on the east coast describe the stink bug invasion as worse than boxelder bugs and lady beetles, combined!

Description (from

Rutgers University): The brown marmorated stink bug has a "shield" shaped body that is characteristic of all stink bugs. The adults are approximately 17 mm (5/8 inch) long with a mottled brownish grey color. ["Marmorated" means marbled, a description of the mottled color on the back.] The next to last (4th) antennal segment has a white band and several of the abdominal segments protrude from beneath the wings and are alternatively banded with black and white. The underside is white, sometimes with grey or black markings, and the legs are brown with faint white banding.