Brown Marmorated
Stink Bug
What is the brown marmorated stink bug?
The brown marmorated stink bug (BMSB), Halyomorpha halys, is a non-native, invasive insect recently discovered in North America. It is a pest of fruits, vegetables, and farm crops. It becomes a nuisance pest when it invades structures to find a place to overwinter.
Where did the BMSB come from and how did it get here?
BMSB is a native insect of China, South Korea, Japan, and Taiwan. The first BMSBs in the United States were found in Allentown, Pa., in 1990s. It is suspected that they were on fruit shipped in packing crates from Asia. BMSB was detected in West Virginia in 2004. BSMB is now found in at least 26 states from Maine to California. It is expected to expand its range across North America.
What does the BMSB look like?
Adults are about ¾-inch long and shaped like a “shield.” They have varying shades of brown on both the upper and lower body surfaces. They differ from other stink bugs in that they have lighter bands on the antennae and darker bands on the membranous, overlapping part at the rear of the front pair of wings. The head and pronotum have small round depressions that resemble coppery or metallic-bluish colored punctures. Stink bugs get their name from the scent glands located on the dorsal surface of the abdomen and the underside of the thorax. BMSBs have small, elliptical-shaped eggs that are light yellow to yellow-red with tiny spines. They attach in rows on the underside of leaves in masses of 20 to 30 eggs that may be shield-shaped.
There are five immature stages known as nymphal instars. They range in length from 1/8 inch at the first stage to ½ inch at the fifth stage. They have deep red eyes and abdomens that are yellowish red in the first stage, progressing to off-white with reddish spots in the fifth stage. Bumps are found before each of the abdominal scent glands on the top surface. The legs, head, and thorax are black. Spines are found on the femur, in front of each eye, and on the lateral margins of the thorax. What damage does the BMSB cause?
The insect feeds on a variety of fruits, vegetables, and farm crops. When BMSB feeds on produce, it causes blemishes known as “cat facing, ” which makes it unappealing and unmarketable as a fresh product. Significant losses have occurred for farmers whose peach and apple orchards have been hit by BMSB. Refer to picture of damage on fruit.
Although BMSBs do not pose a health threat to humans, once they enter a home they can cause alarm while flying around and emitting a strong odor when they are crushed.
How do I get rid of BMSBs?
BMSBs become a nuisance for most people when they begin looking for warm places to spend the winter. The insect’s behavior is similar to that of the multicolored Asian lady beetle as it is attracted to the outside of houses on warm fall days, especially following the first frost. BMSBs look for any entry point they can find into a structure. Cracks as small as 1/16 to 1/8 inch around windows, doors, eaves and overhangs, dryer vents, and other areas provide a means of entrance.
The best method of controlling BMSBs is to prevent their entry into your home. Caulking with a silicone or silicone-latex caulk around window and door frames and replacing damaged window and door screens will help. Use weather stripping around windows and doors and remove window air conditioners following summer use. No insecticides are recommended that will prevent the entry of BMSBs to homes.
Once BMSB enters a home, the only method of control is to vacuum. However, when the insects become alarmed or smashed, they will emit their stink. The best vacuums to use are handheld or bagless because the container can be emptied each time. If you have this type of vacuum, be sure to drop the insects into a disposable bowl or jar containing isopropyl (rubbing) alcohol, which will kill the insect. Releasing the insect outdoors will only cause it to come back in. It is not recommended to use insecticides indoors because the insects can avoid the chemicals by retreating into cracks and crevices. Also, the insecticide itself may be hazardous to humans and pets.
Because BMSBs do not reproduce indoors, it is best to kill any that you find in and around your house and not let them reproduce outdoors next spring.
