WE ARE SEEKING YOUR HELP IN PROTECTING NH FORESTS & LANDSCAPES

This is the Brown Marmorated Stink Bug BMSB. Recently found in Portsmouth, it has the potential to become a serious crop pest throughout New Hampshire.

The Brown Marmorated Stink Bug has five nymphal stages, or instars, and ranges in size from 2.4 mm to 12 mm in length. Unlike the adults who blend in very well with bark, the nymphs are more brightly colored with red and black. The eggs of the Brown Marmorated Stink Bug are often laid on the underside of leaves and a light green in color. They are elliptical in shape and are often deposited in a mass of approximately 28 eggs. The first instars, which have a "tick-like" appearance, are not very active and remain around the hatched egg mass. Nymphs are characterized by dark reddish eyes and a yellowish-red abdomen that is also striped with black. The legs and antennae of the nymphs are black with white banding.

Distinguishing adult characteristics are the white and dark banding on the antennae on the next-to-last antennal segment, red eyes and ocelli, and black and white bands along the outer edges of the thorax.  It has a smooth, untoothed shoulder. Though there one or two similar looking stink bugs, this is the only stink bug that aggregates in houses in large numbers.

The first reported occurrence of the brown marmorated stink bug in the US came at Allentown, PA in 2001, but they are suspected as having been there earlier. Since that time it has moved north and south into most states on the east coast and many states westward across the country. One means of dispersal, for example, has been travel trailers which serve as good overwintering shelters and move hundreds of miles. 

This Asian stink bug feeds on a variety of hosts in the landscape including butterfly bush (Buddleia), pawlonia, hibiscus, zinnia, and sunflower, to name a few. They also attack fruit trees (ornamental or otherwise).  They have potential to do damage to commercial apple, peach, soybean, cotton and other crops. In some areas of the country they are more numerous than the native green stink bug. They may inflict leaf and fruit damage from feeding with needle-like mouth parts.

Egg masses are laid in midsummer by the overwintered females. There are five nymphal stages that go through different colorations and markings. Each stage takes about one week .Adults are slightly larger than 1/2 inch. The overall coloring may vary from brown to gray. New adults emerge late summer, but don't move to overwintering areas for another month or two.

Perhaps the biggest problem for homeowners is the overwintering behavior where the bugs may collect seeking shelter in homes and structures, similar to the multicolored Asian lady beetle. They don't harm people, but can give off an unpleasant odor when crushed or vacuumed. Appearance in houses begins about late September-October.

- Rutgers and Oregon Department of Agriculture.