Each fall many of us battle Asian Lady Beetles as they seek the warmth of our homes as a refuge during the cold winter months.  However, this year in many parts of West Virginia they will have to compete with the new bug on the block.  Like the Asian Lady Beetle, this insect is also an accidental import from Asia.

The brown marmorated stink bug (BMSB), an insect not previously seen on our continent, was apparently accidentally introduced into eastern Pennsylvania. It was first collected in September of 1998 in Allentown, but probably arrived several years earlier.

This true bug in the insect family Pentatomidae is known as an agricultural pest in its native range of China, Japan, Korea and Taiwan. Recently, the BMSB has become a serious pest of fruit, vegetables and farm crops in the Mid-Atlantic region and it is probable that it will become a pest of these commodities in other areas in the United States. 

BMSB becomes a nuisance pest both indoors and out when it is attracted to the outside of houses on warm fall days in search of protected, overwintering sites. BMSB occasionally reappears during warmer sunny periods throughout the winter, and again as it emerges in the spring.

Adults are approximately 17 mm long (25 mm = one inch) and are shades of brown on both the upper and lower body surfaces (Fig. 1). They are the typical "shield" shape of other stink bugs, almost as wide as they are long. To distinguish them from other stink bugs, look for lighter bands on the antennae and darker bands on the membranous, overlapping part at the rear of the front pair of wings. They have patches of coppery or bluish-metallic colored puntures (small rounded depressions) on the head and pronotum (the first segment of the thorax). The name "stink bug" refers to the scent glands located on the dorsal surface of the abdomen and the underside of the thorax which produce an unpleasant odor.