Brown Marmorated Stink Bug (BMSB) Pest Alert

Brown marmorated stink bug (Halyomorpha halys), a native pest of Asia, was first identified in North America in Pennsylvania in 2001. It has since spread throughout most of the United States. It is a very serious pest that feeds on more than 100 different plant species. In 2010, an estimated loss of $37 million due to brown marmorated stink bug feeding was reported by the apple industry in the Mid-Atlantic States.

The stink bug is an excellent hitchhiker and can be moved in shipping containers, wood, packing material, cargo and vehicles. It is also a nuisance to homeowners as the adults aggregate on and in buildings while seeking warm overwintering sites.

Brown marmorated stink bug was first detected in British Columbia in 2015 and is present at low levels in urban areas of Fraser Valley and Vancouver, Brentwood Bay on Vancouver Island and the Okanagan Valley, as of October 2017. High numbers are present in the downtown Kelowna area. Growers and homeowners are asked to send pictures or samples of suspect brown marmorated stink bug to the B.C. Ministry of Agriculture offices or to contacts shown at the right.


Adult: Shield-shaped, 13 – 17 mm long, brown marbled appearance, alternating brown and white markings on the outer edge of the abdomen; can be distinguished from other stink bugs by the presence of distinctive white bands on the last two antennal segments (see adult picture on right). Adults may be confused with other native brown stink bugs and western conifer seed bugs.

Egg: Spherical, white or pale green, 1.6 x 1.3 mm; laid in clusters of 20 – 30 eggs on the underside of leaves.

Immature (nymph): There are 5 immature stages. Nymphs range in size from 2.4 – 12 mm in length and do not have fully developed wings. Ist instar nymphs are bright orange to red in colour; 2nd instar nymphs are black, tick-like; later instars are pear-shaped, brown with white markings on abdomen and legs and white bands on last two antennal segments. 


Brown marmorated stink bug attacks tree fruits, berries, grapes, vegetables and ornamental plants. Ornamental hosts include tree of heaven, chokecherry, catalpa, boxelder, white ash, maple, English holly, and buckthorn. In British Columbia, they have been found on Asian pears, vegetables and wild chokecherries.

Life Cycle

Adults overwinter inside buildings or in protected areas and emerge in early spring. Each female can lay up to 400 eggs throughout the summer on host plants, resulting in overlapping nymphal stages. Eggs hatch in 4–5 days; nymphs mature in about 5 weeks depending on temperature. One to two generations per year are reported in the United States and up to 6 generations in Asia.


Both adults and nymphs feed by inserting their mouthparts into the flesh of fruit or vegetables. Feeding punctures result in small dead areas on fruit, vegetables and leaves. Brown marmorated stink bugs can be a contamination issue for grapes because the presence of a few adults at crush can taint wine.

Adult brown marmorated stink bug

Brown marmorated stink bug