NC State Extension

FAQs: Brown Marmorated Stink Bug

How do I kill BMSB in my house?

Generally, insecticide sprays are not effective due to the mobile nature of the stink bugs, the constant influx of new stink bugs from outside sources, and the difficulty of treating populations without contaminating living areas. In addition, leaving a large number of dead BMSB inside attics, walls, or crawl spaces can attract more unwanted pests, such as carpet beetles. Instead, the simplest, most reliable method is to drop captured individuals into a dish of soapy water to drown them, or to vacuum them and then freeze or discard the vacuum bag. (Some homeowners keep a hand-held, battery-powered vacuum just for BMSB removal.) In areas of high infestation, this is admittedly a time-consuming process, especially during late summer and early fall when BMSB are actively seeking out overwintering sites.

It is best not to squash BMSB in the house, which only worsens the smell, or to live-release them outdoors, where they will eventually come back inside.

How do I keep BMSB out of my house to begin with?

Before large numbers of BMSB begin searching for overwintering sites in late August and September, seal all potential entry points with weatherstripping, caulk, or foam sealant. Check for gaps around windows and doors, place screening over attic ventilation louvers, and make sure there are no gaps or cracks around faucets and piping. An excellent University of Maryland video demonstrates “Exclusion and Execution” techniques for BMSB invaders.

What can I spray for stink bugs in my garden?

In the garden, BMSB most commonly attacks tomatoes, peppers, okra, beans, Swiss chard, peaches, apples, pears, plums and caneberries. Damage consists of discoloration at the feeding site. Rarely is plant vigor affected. Control is difficult due to the limited effectiveness of insecticides and a constant influx of BMSB from outside areas. Pyrethroid insecticides are most effective, so choose products that contain the active ingredient bifenthrin, cyfluthrin, or lambda-cyhalothrin. Options for organic growers are even more limited, and require frequent spraying – possibly every couple of days under intense pressure – that targets immature stages. Organic products that have shown activity include Azera (mixture of azadirachtin and pyrethrins) and Entrust (active ingredient spinosad).

Will stink bugs hurt me, my children, my pets, or my property?

Stink bugs can devastate crops, but otherwise are primarily nuisance pests that do not usually bite, sting, or chew structural materials. In areas with very high populations, they can get into small engines, heat pumps, and other equipment in numbers large enough to cause harm. Dogs, cats, and chickens have been observed eating stink bugs with no ill effects.

Why do BMSB stink?

All stink bugs are capable of emitting a foul-smelling chemical that they use as a defense mechanism when alarmed. The taste of the chemical also deters some birds and other animals from eating stink bugs. An undisturbed BMSB is not likely to stink, but the smell of a large number of agitated stink bugs can be intolerable.

We have always had a few stink bugs around – why are there suddenly so many?

North Carolina has always had several species of native stink bugs, some of which appear quite similar to the brown marmorated stink bug. Native stink bug populations are kept in check by predators and parasites, but the brown marmorated is a recent, accidentally-introduced exotic pest that is not (yet) controlled by native predators and parasites. Learn the differences between the true brown marmorated stink bug and its look-alikes.

What is the future of BMSB in North Carolina?

Since their first appearance in the state in 2009, BMSB have followed a trend already seen in states closer to their original point of introduction: low numbers of insects were first detected in urban areas, then over the next two to three years urban populations increased substantially, spread to rural areas, and began having minor impacts on agricultural fields. In the near future, BMSB is expected to become a significant challenge to gardeners and commercial growers in NC, just as it has been in the mid-Atlantic states since 2010. That year was particularly devasting to growers in the mid-Atlantic region, but subsequent years have seen fluctuating population levels. This indicates that conditions were especially favorable for BMSB during the 2010 season, and populations will not simply increase year after year.

However, our understanding of BMSB is still very incomplete, especially in southern states where its biology and life cycle are not expected to match exactly those of the mid-Atlantic and Northeast. Although insects typically flourish in warmer temperatures, we have not seen the drastic BMSB population increases in NC’s coastal plain that have occurred in the mountains and piedmont. In rural areas with little agricultural activity, BMSB populations remain low to non-existent. Temperatures, day length, presence of wild and cultivated host plants, and the ease with which BMSB can migrate or be moved into an area will all determine the severity of specific local BMSB populations in coming years.

NCSU will continue to research monitoring and trapping methods, chemical control with insecticides, biological control with native predators and parasitoids, and population dynamics in NC’s ecosystems and climates in order to better understand BMSB and reduce populations to manageable levels. Keep checking the BMSB home page for the latest information.