Brown Marmorated Stink Bug

Adults are shield-shaped and mottled brown ("marmorated"), roughly the size of a fingernail. Helpful distinguishing features include alternating light and dark bands on the antennae and along the edge of the abdomen. Eggs are laid in tidy clusters on the underside of leaves, and the nymphs are more rounded and often more brightly patterned than adults.

Several native stink bugs look broadly similar, so the banded antennae and abdominal margins are useful checks. A defensive odour when disturbed is characteristic of stink bugs generally and is the origin of the common name.

Overwintered adults become active in spring, feed, and lay clusters of eggs on host plants. Nymphs pass through several instars before maturing, and the number of generations per year depends on climate, with warmer regions supporting more. As days shorten in autumn, adults seek sheltered overwintering sites, including buildings.

Because adults are highly mobile and use many hosts, they move between wild vegetation, orchards, and field crops through the season, which complicates monitoring and control on any single crop.

Feeding punctures on developing fruit cause dimpling, corky or water-soaked areas, and internal discoloration that reduce marketability. On legumes and other seed crops, feeding on pods and seeds can cause deformity, abortion, and quality loss. Damage is often concentrated at field and orchard edges where bugs move in from surrounding vegetation.

The host range is very broad and includes tree fruit such as apple, peach, and pear, grape, and field crops such as soybean and maize, along with many vegetables including tomato and sweet pepper.

Pheromone-baited traps are widely used to detect activity and time management decisions, and visual inspection focuses on crop edges and fruit clusters for adults, nymphs, egg masses, and early feeding injury. Because pressure often comes from the field margin, monitoring border rows closely helps target any response and reduce unnecessary whole-field treatment.

Management combines monitoring, biological control, and cultural tactics within an integrated pest management framework, with attention to conserving natural enemies.

• Monitor with pheromone traps and edge scouting to time and target any action
• Conserve and encourage natural enemies, including egg parasitoids that attack stink bug eggs
• Consider border-focused or perimeter management where damage concentrates at field edges
• Exclude and remove overwintering adults from buildings by sealing entry points
• Coordinate at an area-wide scale given the pest’s mobility and broad host use