The brown marmorated stink bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae; Figure 1) is a landscape and agricultural pest in the United States. It was introduced from Asia in the mid-1990s, and quickly spread to the entire United States because of its overwintering behavior. They seek dark and dry sites—such as a vehicle parked near trees—in the fall in which to overwinter.
The Early Detection and Distribution Mapping System shows 95 positive reports throughout Georgia; it is established in the Piedmont region of the state. This pest is reported to feed on more than 170 plant species, including fruits, vegetables, and ornamental plants. The BMSB also is a nuisance pest as they aggregate and overwinter in man-made structures beginning in late fall.

Figure 1. Adult stage of the brown marmorated stink bug, Halyomorpha halys (Stål). Photo: Ken Childs, Bugguide.net.
Biology and Behavior
The BMSBs overwinter (diapause) as adults, and do not feed during this time. In spring, they emerge from overwintering sites and seek immediate nutritional resources from developing flowers and fruits before laying eggs. The BMSB undergoes three life stages: egg, nymph (five nymphal instars), and adult (Figure 2). A female lays eggs in a mass of about 28 eggs, and can lay between two and 15 egg masses during her lifetime. The light-yellow to light-green, barrel-shaped eggs are glued to the host’s surface (leaf, fruit, stem; Figure 3). First instars have an oval- and tick-like appearance, with mottled orangish-red and black coloration, and remain aggregated around the egg mass (Figure 4). Subsequent instars disperse while seeking food. Second- to fifth-instar nymphs are black-and-white colored and have well-defined white bands on their legs and antennae (Figure 5). In the laboratory, the nymphs take about 43 days to grow before molting into adults. The adults are grey-brownish and shield-shaped, with two white bands on their antennae and mottled white-and-black stripes along the lower margins of the body (Figure 1). The BMSB differs from the brown stink bug, Euschistus servus, by the presence of white bands on antennae and legs (Figure 8). Adults can live up to 119 days. They are often found aggregated on host leaves (Figure 6).

Figure 2. Life cycle of brown marmorated stink bug. Illustration: Fawad Khan.
There are two generations of BMSBs per year in Georgia. The nymphs from the overwintering adults mature into summer adults by late July or August, and the nymphs from the summer adults mature into overwintering adults in September or October. These adults seek overwintering sites in the fall. BMSBs are strong flyers and can fly long distances, as much as 3.7 miles in a month. In addition to flight, the fifth instar of BMSB can walk up to 65 ft in 4 hr.
Figure 3. Eggs of the brown marmorated stink bug. Photo: Yurika Alexander, Bugguide.net.
Figure 4. First-instar nymphs of the brown marmorated stink bug. Photo: Marcia Morris, Bugguide.net.
Figure 5. Nymphs of brown marmorated stink bug with prominent black and white bands on antennae and legs. Photo: Shimat V. Joseph.
Figure 6. Nymphs and adults of the brown marmorated stink bug aggregating on catalpa leaves. Photo: Shimat V. Joseph.
Host Plants and Damage
Brown marmorated stink bugs can feed on plants from multiple families. In Georgia, more than 150 ornamental plant species are potential hosts of BMSBs. The invasive tree-of-heaven (Ailanthus altissima) is a preferred host for BMSBs in the landscape (Figure 7). Tree-of-heaven is the early host in pine-oak forests in the Piedmont region of Georgia. BMSB populations were observed where flowering dogwood tree (Cornus florida), yellow-poplar (Liriodendron tulipifera), Chinese privet (Ligustrum sinense), winged elm (Ulmus alata), sweetgum (Liquidambar formosana), maple (Acer spp.), oaks (Quercus spp.), walnut (Juglans spp.), crape myrtle (Lagerstroemia spp.), and honey locust trees (Gleditsia triacanthos) are present.
BMSB adults and nymphs attack a wide range of ornamental shrubs and trees. Please see pp. 6–10 in the PDF document for Table 1 (click on the View PDF button), which cross-references the articles listed below with known ornamental-plant hosts of the BMSB. The table includes both scientific names and common names.
