Description
The eggs of H. halys are elliptical (1.6 x 1.3 mm) and light green in color. They are attached side by side in groups of 20 to 30 on the underside of leaves (Figure 1). There are five nymphal instars. They range in size from 2.4 mm at the first instar to12mm in length at the last instar. Deep-red eyes characterize the immature stages. The abdomen is a yellowish-red in the first instar and gradually turns to off-white with reddish spots in the fifth instar. Adults are approximately 17 mm long and are generally brown in color. Distinguishing characteristics found on adult H. halys include lighter bands on the antennae and darker bands on the membranous, overlapping part at the rear of the wings (Figure 2). They also have patches of coppery or bluish metallic-colored punctures on the head and pronotum. The scent glands are located on the dorsal surface of the abdomen and the underside of the thorax. It is these glands that are responsible for producing the pungent odor that characterizes "stink bugs."

Damage and Control
In its native range, H. halys feeds on a variety of fruits and other host plants. In Pennsylvania, it has been observed feeding on many ornamental plants, weeds and trees, including black cherry (Figure 3). It is uncertain if H. halys will become a widespread pest. These insects are not known to harm humans or reproduce inside of houses. However, they can become a nuisance once inside the home and their odor quite offensive. No control recommendations are currently available.

Sources and Credits
Penn State Entomology Bug Alert, Yellow-Brown Stink Bug, NP-15, www.ento.psu.edu/bugalerts.htm. Cornell University, Cornell Chronicle, East Asian stink bugs.
www.news.cornell.edu/Chronicles/11.1.01/stinkbugs.html
Photo credits: David R. Lance, USDA APHIS PPQ, www.insectimages.org, and the USDA Forest Service.