Brown Marmorated Stink Bug

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The brown marmorated stink bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an exotic insect new to North America. Large numbers of adult BMSB were first identified in fall 2001 in Allentown, PA; however, undetermined sightings likely date as far back as 1996. This Asian native, sometimes called the yellowbrown or East Asian stink bug, has since spread across much of the U.S. BMSB is a known pest of fruit trees and legumes in its native China, South Korea, Japan, and Taiwan.

Host Range

BMSB is considered polyphagous, which means it has been recorded feeding on a wide range of host plants. Commonly damaged plants include ornamentals (catalpa, eastern redbud, southern magnolia, crab apple, and many others), specialty crops (apple, peach, apricot, cherry, pear, almond, pepper, tomato, eggplant and more), and field crops (corn, soybean, sunflower, etc.)

Brown marmorated stink bug nymph.
Brown marmorated stink bug nymph.
Brown marmorated stink bug adults on fruit.
Brown marmorated stink bug adults on fruit.

Life History and Identification

BMSB is a shield shaped stink bug ranging in length from 14 to 17 mm and is dark mottled brown. The last two antennal segments have alternating broad light and dark bands. The exposed abdominal edges also have alternating dark and light banding. From June to August, females lay clusters of 20–30 light green, barrelshaped eggs on the undersides of leaves. Newly hatched nymphs are yellowish mottled with black and red. Older nymphs are darker with banded legs and antenna, like the adults. Adult BMSB are most similar in appearance to Brochymena, a very common group of native grey-brown stink bugs. However, Brochymena spp. lack the alternating light and dark antennal markings. Brochymena spp. also have distinct teeth on the lateral edges of the pronotum, whereas the lateral pronotal edges of BMSB are smooth.

Brown marmorated stink bug eggs surrounded by hatching nymphs.
Brown marmorated stink bug eggs surrounded by hatching nymphs.
Brown marmorated stink bug adult.


Household Pest

BMSB enter buildings in the fall when they are seeking sheltered locations where they can spend the winter in hibernation in attics and wall voids. Typical entry points include cracks and gaps around windows and doors, between the foundation and siding, between the siding and soffit, around a chimney, etc. BMSB secrete aggregation pheromones which attract more individuals which can to large numbers of BMSB in homes and buildings. Because they overwinter indoors, one of the ways BMSB spreads is in mailed packages and luggage, as well as, vehicles and motor homes. Prevent entry of BMSB by repairing screens, caulking cracks, removing window AC units, etc. Insecticides applied outside of homes and buildings before the bugs enter can also help reduce the number coming indoors. Once indoors, vacuuming and other methods of physical removal are the best management options. When BMSB enters a new area it is household pest at first and it is several years before populations become large enough that plant damage begins to occur.

Plant Pests

BMSB feeds on a wide range of fruit, field crops and ornamental trees and plants. The economic damage they cause is made worse by the fact that they prefer to feed directly on the fruit/reproductive part of the plant which is often the harvestable portion of the plant. BMSB feeding causes small necrotic areas on leaves and fruit. Fruit damage may include water-soaked lesions and/or cat-facing damage, ranging from mild to severe. In the Mid-Atlantic region where BMSB populations are the largest they have cause millions of dollars in damage to produce and have disrupted integrated pest management programs of other pest insects by requiring repeated insecticide applications. Pyramid style traps with lures are used by growers to monitor for BMSB. Growers can treat with an insecticide if a threshold trapped is reached for their crop or the capture of BMSB can signal that more intensive crop scouting is needed. Research into biological control agents is ongoing. For information on management options specific to your situation or to find out if BMSB is present in your area please contact your local extension agent.

For more information and images of BMSB, visit


Content Reviewed by:

Stanton Gill, University of Maryland Cooperative Extension

Gary Bernon, USDA–APHIS

Richard Hoebeke, Cornell University

George Hamilton, Rutgers University Cooperative Extension

Anne Nielsen, Rutgers University

Peter Shearer, Rutgers University Cooperative Extension

Gaye Williams, Maryland Department of Agriculture

Karen M. Bernhard, Lehigh County, Pennsylvania, Cooperative Extension

Grzegorz Krawczyk, Pennsylvania State University

Photographs courtesy of: G. Bernon, K. Bernhard, G. Hamilton, and D. Matadha.

Editor: Julie L. Todd, Technically Correct Scientific Communications, State College, PA.

Graphic designer: Gretchen Wieshuber, Studio 2D

This work is supported by the Crop Protection and Pest Management Program (2018-70006-28884) from the USDA National Institute of Food and Agriculture.

This publication was produced and distributed in cooperation with USDA–CSREES Integrated Pest Management Centers, Maryland Department of Agriculture, USDA-APHIS, and the Land-Grant University System.

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August 2019