Halyomorpha halys

(Stål, 1855)

Brown Marmorated Stink Bug, BMSB

Halyomorpha halys is an shield bug native to East Asia that has become a major agricultural and nuisance pest across North America, Europe, and beyond. First detected in Pennsylvania in 1998, it has spread to at least 47 U.S. states, 4 Canadian provinces, and numerous European countries. The is highly , feeding on over 300 plant species across 49 , with particular preference for Rosaceae. Its invasion success is facilitated by high mobility, broad range, and absence of natural enemies in invaded ranges. Natural control is emerging through of the Trissolcus japonicus and other native and .

Halyomorpha halys by (c) Kimberly, some rights reserved (CC BY), uploaded by Kimberly. Used under a CC-BY license.

2024 09 29 Halyomorpha halys by Slimguy. Used under a CC BY-SA 4.0 license.

Halyomorpha halys Calceranica by Syrio. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Halyomorpha halys: /ˌhælioʊˈmɔrfə ˈheɪliːs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Shield-shaped body with distinctive marbled brown coloration; alternating dark and light bands on the last two antennal segments; exposed lateral margins of the show alternating light and dark banding. are approximately 12–17 mm in length. Nymphs lack fully developed wings and have a more rounded appearance, with early instars showing dark reddish and yellowish-red abdomens with black stripes. The can be distinguished from native stink bugs by the white bands on the and the smooth shoulder margins (native species often have toothed or spined shoulders).

Images

Habitat

Agricultural landscapes including orchards, vineyards, row crops, and vegetable fields; suburban and urban environments where it overwinters in human structures; natural sites include sheltered locations beneath tree bark and in rocky crevices.

Distribution

Native to East Asia (China, Japan, Korean Peninsula, Taiwan). in North America (first detected Pennsylvania 1998; now present in 47 states and 4 Canadian provinces), Europe (present in at least 15 countries including Switzerland, Germany, France, Italy, Hungary, Serbia, Ukraine, Turkey, Belgium), South America (Chile), and Oceania (Guam).

Seasonality

emerge from sites in spring when temperatures warm, typically March–April in temperate regions. Multiple overlapping per year in favorable climates; peak nuisance invasions into structures occur September–October as adults seek overwintering shelter. Activity extends later into autumn with warming temperatures.

Diet

Highly herbivore feeding on over 300 plant from 49 . Preferred include Rosaceae (apple, pear, peach, cherry, plum), hazelnut, grape, soybean, corn, tomato, pepper, and numerous woody ornamentals. Feeding causes direct damage to fruits, nuts, seeds, and vegetative tissues through .

Life Cycle

with , five nymphal instars, and stages. Adults overwinter in , emerging in spring to feed on plants for several weeks before reproductive maturity. Females deposit egg masses (typically 20–30 eggs) on undersides of leaves. Nymphs develop through five instars over approximately 4–6 weeks in summer conditions. Multiple occur annually in warmer regions; single generation in northern limits.

Behavior

Aggregates in large numbers using male-produced combined with methyl decatrienoate synergist; this exploited for monitoring and attract-and-kill management. engage in seasonal between sites and plants. During autumn , exhibits strong attraction to vertical surfaces, particularly dark-colored north- and east-facing building walls and doorways. Enters buildings not for warmth but for sheltered overwintering sites analogous to natural refugia. Does not typically reproduce indoors due to absence of suitable food for nymph development, though occasional -laying on houseplants has been observed.

Ecological Role

Major agricultural pest causing significant economic damage through direct feeding injury to crops. Serves as prey for diverse including Chinese mantis, wheel bug, black and yellow garden spider, ground beetles, and katydids. Native (including Telenomus turesis in Turkey and Ooencyrtus pityocampae in some regions) and introduced Trissolcus japonicus provide . Subject to by microsporidian Nosema maddoxi. Gut 'Candidatus Pantoea carbekii' is essential for nymphal development and survival.

Human Relevance

Significant agricultural pest causing millions in crop losses annually; major nuisance pest due to autumn home invasions. Management relies on physical exclusion (sealing entry points), vacuuming or sweeping for indoor control, and targeted applications. Attract-and-kill strategies using -baited traps reduce use in orchards. Research ongoing on insecticide-treated netting for residential exclusion. Not a structural pest or ; defensive secretions can cause allergic reactions in sensitive individuals.

Similar Taxa

Native stink bugs (various Pentatomidae)Lack white antennal bands and abdominal margin banding; often have spined or toothed shoulder margins versus smooth margins in H. halys.
Chinavia hilaris (green stink bug)Uniformly green coloration without marbled pattern; lacks contrasting antennal bands.
Plautia stali (oriental stink bug)Produces methyl decatrienoate, which synergizes H. halys ; similar body shape but different coloration and pattern.

Misconceptions

Common belief that stink bugs enter buildings in winter to 'get warm' is incorrect—they seek sheltered sites analogous to natural refugia beneath bark, entering regardless of indoor temperature. Another misconception that they breed indoors; while occasional -laying on houseplants occurs, sustained indoor are extremely unlikely due to lack of food resources for nymphs.