The brown marmorated stink bug (Halyomorpha halys) is expected to arrive in Missouri in 2011 although it may already be here in very low numbers. This exotic stink bug was first found in Allentown, Pennsylvania in 1998 and has steadily moved outward from its original location during the past twelve years. As of 2010, this insect is reported from 27 states including Illinois, Kentucky, and Tennessee. This insect is native to mainland China and was probably introduced into the U. S. in the early 90's in cargo from either China or Japan. This insect is in the order Hemiptera (true bugs) and family Pentatomidae (shield shaped insects). Similar to other stink bugs, it inserts a long proboscis or mouthpart into host plants in order to feed on plant juices.
Although the brown marmorated stink bug can be a severe pest of numerous fruit and vegetable crops, it also damages soybean in Japan. It is often a major pest in the field and also can be a major pest inside structures. Similar to the Asian ladybird beetle, it readily invades homes during the fall months to overwinter. Once in the house, this stink bug will quickly release a very repulsive smell if disturbed. Many people who have experienced the foul odor say that it is often necessary to leave the room for several hours to allow the stench to decrease to tolerable levels. Several states report that the best method of eliminating this insect from houses is to suck them up with a vacuum and immediately change the vacuum bag or to let them crawl onto a piece of paper and transport them back outside. The vacuum method may result in some odor remaining in the vacuum after the bag has been removed. Most other methods of control in houses, including use of insecticides, apparently cause the insect to emit their defensive odor when disturbed. Squashing the insect is not a recommended way to eliminate this insect. Thoroughly sealing all cracks and crevices around windows doors, crawl spaces, and other possible entry points prior to fall will help provide barriers to house entry. Another method sometimes used in conjunction with sealing entry points is to have a certified pest control specialist spray the area around and on the structure with a synthetic pyrethroid in order to repel the adults as they search for overwintering sites.
The brown marmorated stink bug can be confused with several other stink bug species already present in Missouri. It is brown to brownish-gray in color on both top and bottom surfaces. It is about ¾-inch in length and about as wide as long. Two identifying characteristics are a white band on the next to last (4th) antennal segment and a row of alternating white and black markings located around the edge of the shell where the front and back wings overlap. Nymphs are red and black when first emerging from eggs, but take on a more gray color as they grow through their immature stages. At present it is thought that only one generation is produced per year in the U.S. although multiple generations have been reported from several Asian countries. The adult overwinters to emerge in late May and June to feed throughout the summer on such plant species as apples, cherries, peaches, pears, blackberries, green beans, lima beans, peppers, sweetcorn, field corn, and soybean. Both adults and nymphs attack host plants. In contrast to most other Missouri stink bugs, brown marmorated stink bug adults may live for several years. No harm to humans by this insect has been reported.
REVISED: October 2, 2015