Field Identification
A large, shield-shaped invasive stink bug that pierces fruit, pods, and nuts, leaving corky spots, dimpling, and rot entry points. It aggregates on buildings in fall like its boxelder cousins and taints harvests of tomato, pepper, apple, pear, stone fruit, corn, soybean, and many specialty crops. Established and spreading across temperate and subtropical growing areas of the Americas wherever winters are not extreme—roughly zones 5–11 with regional pockets beyond—populations spike after mild winters and long growing seasons.
Adults are mottled brown, about 5/8 inch (17 mm), with smooth “shoulders” and alternating light-dark bands on antennae and abdomen edges visible at rest. Nymphs pass through instars from red-and-black rounds to mottled forms resembling small adults. Eggs are light green, barrel-shaped, laid in tight clusters on leaf undersides with a shiny deposit—distinct from native stink bug egg masses.
How to Deal With It
Organic Control Methods
Pyrethrin, neem, or kaolin clay can deter feeding and must be applied with excellent coverage to fruit zones; reapply after rain. Insecticidal soap has limited effect on adults but can suppress nymphs on tender growth. Rotate materials and respect pre-harvest intervals on edible crops.
Native parasitoids such as Trissolcus spp. (egg parasitoid wasps) attack eggs where established; generalist predators including spiders, assassin bugs, and birds take nymphs. Avoid orchard-wide sprays that flatten beneficial complexes during egg-laying windows.
Plant perimeter trap crops of sunflower, sorghum, or millet to concentrate bugs away from high-value rows; destroy or mow trap strips after peak aggregation. Manage weedy hosts along field edges. Harvest tree fruit promptly when monitors show rising captures—delayed picking accumulates stink bug injury.
Shake adults and nymphs from shrubs into a wide bucket of soapy water during cool mornings. Fine exclusion netting on high tunnels and individual fruit trees reduces oviposition when vents are managed for heat. Sticky monitoring traps help time sprays without replacing scouting on fruit.
Deploy pheromone-baited traps where legal and available to track adult movement into blocks. Seal homes and outbuildings before fall flights. Keep detailed maps of hot spots—BMSB uses the same sun-warmed fence lines year after year.
Let Nature Handle It
Natural Enemies
- Trissolcus spp. (Platygastridae)
- Arachnid Predators (Spiders)
- Assassin Bugs (Reduviidae)
- Insectivorous Birds
Threat Map