Background
The brown marmorated stink bug (BMSB, Halyomorpha halys) was accidentally introduced from Asia to North America in the 1990s, with the first detection occurring in Allentown, Pennsylvania, in September 1998. Its first appearance in North Carolina was in Forsyth County in 2009, and it then spread rapidly throughout the piedmont and mountain regions of the state. It has not become as prevalent in the coastal plain, although there have been isolated occurrences. As of March 2026, BMSB had been confirmed in 80 of NC's 100 counties (and in 47 US states).
There are many other species of stink bug in North Carolina, including the common brown stink bug (Euschistus servus) and green stink bug (Chinavia hilaris). Most of these species are native to the Southeast and have many natural enemies that keep their populations in check. Historically, they have caused some damage to crops but can usually be managed easily, and they do not overwinter in structures. Some species actually prey on other insects and are beneficial to humans.
Brown marmorated stink bug damage on (top to bottom) tomato, peach, and apple.
In contrast, BMSB has few native natural enemies in North America, making it a highly destructive pest on a wide variety of crops, and an incredible nuisance when it invades homes and other buildings in the fall. It usually establishes first in urban landscapes, roadside vegetation, and structures that provide attractive overwintering sites. This was the case in North Carolina, where most early reports came from property owners between Raleigh and Asheville (the I-40 corridor) who experienced BMSB "invasions" in late summer. Sightings in home gardens and on commercial farms increased from extremely isolated instances in 2010 to widespread problems by 2015. In some cases, populations became large enough that emergency pesticide applications were necessary to prevent extensive crop loss. By 2025, BMSB had become a regular pest on most farms, but ongoing research has helped growers adopt routine monitoring and pesticide programs to minimize crop damage.
BMSB in North Carolina Fact Sheet
(Our research focuses primarily on controlling BMSB in agriculture. For information on dealing with BMSB around the house, visit our FAQ page.)
Life cycle in North Carolina
In September and October, brown marmorated stink bug adults move into structures, dead trees, and other sheltered places to overwinter. They may move around on warm days, but generally they remain in diapause, a hibernation-like state of reduced activity. While overwintering they do not feed or lay eggs. Except for their annoying presence, they do not harm people or pets. They usually do not damage property, although in large numbers they have been known to clog heat pumps and power equipment.
In spring, overwintered adults leave their shelters and are seldom found indoors again until late summer. They move onto nearby trees and shrubs where they mate and lay eggs on suitable host plants. By midsummer, the eggs hatch and the nymphs pass through five stages (“instars”) before becoming adults. Many of these 1st-generation BMSB invade farms and gardens as fruit and vegetables mature. Later in the season they may move into soybeans and other field crops. When conditions are ideal (i.e., long periods of warm temperatures with favorable hosts present), a second generation of adults may be produced.
When days become shorter in early August, adult BMSB stop laying eggs. In September and early October, they begin looking for overwintering sites, and by late autumn, most individuals have settled back into buildings and other sheltered places. The months of September and October, when adults are aggregating in large numbers, are usually when new invasions are observed.
What's being done?
Beginning in 2011, NCSU entomologists were part of a collaboration of over 50 scientists working on the biology and management of BMSB in the United States. Initially we helped introduce emergency pesticide programs to minimize crop damage, which had totaled $37 million in the 2010 mid-Atlantic apple harvest alone. Broad-spectrum pyrethroids and neonicotinoids proved to be the most effective chemicals for managing BMSB, but their extensive use is not sustainable. They have increased production costs and disrupted IPM programs, resulting in secondary pest outbreaks and greater risk to non-target organisms. Some crops, such as ‘Granny Smith’ apples, continue to be heavily damaged by BMSB despite the use of aggressive insecticide programs.
Therefore, in recent years the focus of BMSB research has shifted toward finding management strategies that will be effective and safe over the long term. In recent years, our collaborative network has developed convenient monitoring traps and attractants, which have helped gauge the severity of local BMSB populations and establish preliminary spray thresholds, reducing the frequency of insecticide applications. We have gained a clearer understanding of the BMSB life cycle in North America, and identified many of the wild plants (several of which are invasive exotics) that BMSB favor to complete their development. We have tested non-insecticidal management tools, such as trap crops, attract-and-kill stations, and protective netting – approaches which may not be practical on many farms, but have shown promise in small or specialized operations.
We have also evaluated the effectiveness of native and non-native predators and parasitoids of BMSB. The most promising of these, Trissolcus japonicus, is a native of Asia that has entered North America with BMSB, and it has the potential to reduce BMSB populations at the landscape level. In coming years, we will participate in a multi-state collaborative project quantifying the effectiveness of T. japonicus in parasitizing BMSB egg masses in apple and peach orchards, with the hopes of eventually augmenting T. japonicus populations in North Carolina.
Report your experiences
- Since 2011, NC State University has been collecting information about BMSB occurrences through an online survey. If you live in NC and have seen BMSB in an area not currently represented on our map, please complete our short survey.
Frequently asked questions
Click the FAQ page for the most common concerns.
