The brown marmorated stink bug is a nonnative, invasive species spreading in North America. This insect is present in Missouri, and its range and numbers are expected to increase.
Adult brown marmorated stink bugs are mottled brown, black, and dark red on the back, with a lighter tan, beige, or whitish underside. They have distinctive white bands on the antennae and on the legs, and they have alternating light and dark bands along the outer margin of the abdomen. They are slightly larger than most of our native stink bug species. Adult brown marmorated stink bugs also have smooth (not spiny) “shoulders” (smooth humeral margins).
Immature stages: The eggs are whitish green or bluish, spherical, and usually laid in a cluster of about 25–30 on the undersides of leaves. When they first hatch, the nymphs have a black head and thorax, and the abdomen is orange with black markings. After that stage, they are primarily gray or black and no longer have bright orange abdomens. They have white banding on the blackish antennae.
Similar species:
To learn about Missouri’s stink bugs in general, visit their group page.
For more information about this invasive insect, visit these brown marmorated stink bug pages:
Length (not including appendages): ½ to ¾ inch.
Potentially statewide.
Habitat and Conservation
This stink bug species is native to east Asia and was introduced to the United States in the 1990s. Apparently it arrived via shipping containers in Pennsylvania. It has been expanding its range invasively since then, especially in the mid-Atlantic region and on the east and west coasts. It is expected to expand its range nearly throughout the Lower 48.
This stink bug species is economically harmful to fruit, vegetable, and field crops. Because the brown marmorated stink bug eats a wide variety of plant species, it occurs in a wide variety of habitats.
Also, its large numbers that enter homes to overwinter are a nuisance. These insects do not bite humans or animals, and they do not damage buildings, but when crushed, frightened, or sucked into a vacuum cleaner, they emit a stinky odor from glands, making them unpleasant to deal with.
Food
Brown marmorated stink bugs feed on a wide variety of plants, using their strawlike mouthparts to pierce into plant structures and then suck out juices. Although they can suck juices from leaves, they especially focus on developing fruits, including beans, corn kernels, flower buds, immature seeds, and other developing plant reproductive structures.
They readily switch host plants, so they can find foods throughout the whole growing season. In the United States, this species has been recorded feeding on at least 175 species of plants, many of them economically important crops. See Human Connections for some of the plants they damage.
Status
Nonnative invasive insect, native to east Asia. Spreading throughout Missouri and in North America. Pest of orchards, vegetables, corn, soybeans, and other crops. Pest of landscaping plants. Nuisance pest in homes.
Life Cycle
Like other types of stink bugs, the brown marmorated stink bug starts life as an egg. After hatching, it eats, grows, and molts, progressing through five immature stages. Each immature stage lasts about a week. The final molt brings them to their winged adult stage; they typically mate about two weeks later. A female may produce several egg clutches after mating. In fall, adults seek sheltered places, including cracks and other entrances in buildings, and overwinter. In spring they become active again and start seeking food.
In Missouri, there are probably one or two generations a year. In southern states, there may be up to five generations annually. The milder the climate and longer the growing season, the more generations there may be each year.
Human Connections
Invasive insects that damage crops are harmful not just for farmers but also for anyone who purchases crops and the products made with those crops. They cause millions of dollars in crop damages. They damage the fruits of apples, pears, peaches, nectarines, apricots, cherries, grapes, raspberries, blackberries, blueberries, beans (including soybeans, green beans, lima beans, and green peas), peppers, tomatoes, eggplant, okra, swiss chard, sorghum, sunflower, and corn. In the case of corn and soybeans, they pierce through the husk or pod and suck juices from the developing kernels and beans below. They also damage leaves.
In addition to orchards and food crops, these insects also damage ornamental and landscaping plants, including redbud, catalpa, crabapple, mulberry, maples, and serviceberry.
Much like the Asian lady beetle, brown marmorated stink bugs are a nuisance to people because they can enter homes in large numbers to seek shelter in autumn, and they emit a foul-smelling chemical when threatened or squashed. As with other insects that enter buildings to overwinter, you can prevent them from getting in by sealing cracks around windows, siding, air conditioner openings, and so on. Once indoors, they walk on walls and windows, fly around lamps, and generally are annoying.
The brown marmorated stink bug has also been introduced to Europe, Eurasia, and South America; thus it is invasive globally. They like to hide in human-built structures and are readily moved to new continents via shipping containers. They also spread from state to state in cars, trucks, planes, and railcars.
“Marmorated” means “marbled,” in reference to the mottled coloration.
Ecosystem Connections
Nonnative invasive organisms are a detriment to our native habitats and ecosystems and, ultimately, all the plants and animals that rely on them. In addition to competing against our native species, they can also introduce and transmit diseases among our native species. Many invasive insects arrive in North America as inadvertent hitchhikers in shipping containers, wooden pallets, and cartons of products from foreign lands.
When people apply broad-spectrum pesticides to combat brown marmorated stink bugs, the chemicals can damage populations of nontarget insects, including pollinators and species that are natural enemies of crop pests. This can impair the success of environmentally friendly integrated pest management efforts.
