Brown marmorated stink bugs (BMSB), recognizable by their distinctive shield-shaped, mottled brown bodies, are an invasive insect species widespread across the United States. These insects, measuring about 14 to 17 mm long, roughly the size of a dime, are not physically dangerous to humans or pets. However, they can be significant agricultural and household pests.
Threats to Humans and Pets
Their mouthparts are designed for piercing plant tissues and extracting juices, not for breaking skin or feeding on blood. These insects are not known to transmit diseases to humans or animals.
When disturbed, handled, or crushed, brown marmorated stink bugs release an unpleasant, pungent odor from scent glands located on their underside. This defensive secretion serves to deter predators. The smell is off-putting and can linger, but it is not harmful to people or pets. In rare instances, some individuals might experience mild skin irritation or allergic reactions from contact with the bug’s secretions, but severe reactions are uncommon.
Harm to Plants and Homes
Brown marmorated stink bugs are primarily recognized as agricultural and garden pests due to their feeding habits. Both adult and immature stink bugs use piercing-sucking mouthparts to feed on a wide variety of fruits and vegetables. This feeding can cause significant damage, including dimpling, pitting, and discoloration on fruit surfaces. On leaves, feeding can result in stippled areas.
Beyond agricultural damage, brown marmorated stink bugs become a nuisance when they invade homes and other structures. As cooler weather approaches in late summer and early fall, adult stink bugs seek sheltered places to overwinter, often congregating in large numbers inside houses. While they do not cause structural damage or reproduce indoors, if disturbed, they release their characteristic odor, which can be difficult to eliminate.
Dealing with Brown Stink Bugs
Managing brown marmorated stink bugs involves both preventing their entry into homes and controlling their populations in gardens. The most effective strategy for keeping them out of homes is mechanical exclusion. This includes sealing cracks and crevices around windows, doors, utility pipes, and siding with caulk or foam sealant. Repairing or replacing damaged window and door screens and installing weather stripping can also significantly reduce entry points.
For garden management, physical removal methods are often recommended. Hand-picking bugs and dropping them into a bucket of soapy water is an effective way to reduce populations. Using a hand-held vacuum cleaner can also be efficient, with bugs disposed of in soapy water to prevent odor. Eliminating weeds and plant debris from garden areas can help reduce their habitat. Planting certain trap crops around garden perimeters may attract them away from desired plants.