Stink bugs belong to the family Pentatomidae, and dozens of species are common across North America. Some destroy crops, some are actually beneficial predators, and a few are just nuisances that invade your home every fall. Knowing which type you’re dealing with determines whether you should remove it or leave it alone.
Brown Marmorated Stink Bug
This is the species most people mean when they say “stink bug.” The brown marmorated stink bug is native to East Asia and was first confirmed in the United States in 2001 in Allentown, Pennsylvania, though specimens were collected as early as 1996. It likely arrived in shipping materials and has since spread throughout much of the country.
Adults are shield-shaped and mottled brown, with alternating light and dark bands along the outer edges of the abdomen. The most reliable way to identify one is by the white banding on the antennae, which gives them a striped appearance. These are the stink bugs most likely to show up inside your house in fall, clustering around windows and doorframes as they seek warm places to overwinter.
They’re also the most economically damaging. Brown marmorated stink bugs feed on a huge range of fruit and vegetable crops. On tomatoes, their feeding creates dark pinpricks surrounded by discolored halos, and the tissue beneath turns corky. They can also carry yeast and other pathogens on their mouthparts, introducing decay into fruit as they feed. Just one-third to one-half of a stink bug per plant, on average, can result in about 5% damaged fruit in a field.
Green Stink Bug
Two green species are widespread and often confused with each other. The green stink bug (Chinavia hilaris) ranges across most of eastern North America, from Quebec west through southern Canada and down to Florida and California. The southern green stink bug (Nezara viridula) overlaps in warmer regions. Both are bright green, shield-shaped, and roughly half an inch long.
Telling them apart without a magnifying lens is tricky. The key anatomical difference involves the scent gland opening on the underside of the body: in the green stink bug, the external channel extends well past the midpoint of the surrounding plate, while in the southern green stink bug it falls short. For practical purposes, both species cause similar feeding damage to crops, particularly soybeans, tomatoes, and other fruiting vegetables. They pierce plant tissue with needle-like mouthparts and inject digestive enzymes, leaving behind the same dimpled, discolored marks characteristic of stink bug damage.
Harlequin Bug
The harlequin bug is one of the easiest stink bugs to identify. At just a quarter to three-eighths of an inch long, it’s smaller than most species, but its coloring is unmistakable: a glossy black body covered in vivid red, orange, or yellow markings that vary between individuals. This bold patterning serves as warning coloration, signaling to predators that the bug tastes terrible.
Harlequin bugs are specialists on plants in the cabbage family. They attack nearly all crucifers, including garden crops like kale, cabbage, and flowering cabbage, plus weeds like wild mustard, shepherdspurse, and peppergrass. When populations are heavy, they’ll also move to squash, corn, beans, asparagus, okra, and tomato. If you grow brassicas in the southern half of the U.S., these are among your most persistent pests.
Spined Soldier Bug
Not all stink bugs are pests. The spined soldier bug is a predator that feeds on caterpillars, beetle larvae, sawfly larvae, and even other stink bugs. It’s been recorded preying on over 100 species of pest insects, making it one of the more valuable natural enemies in gardens and agricultural fields.
You can distinguish it from plant-feeding species by its sharply pointed “shoulders,” the front outer margins of the thorax that stick out like small spines. Adults also have a dark line on the membranous tip of each forewing. Unlike herbivorous stink bugs that keep their mouthparts tucked underneath, spined soldier bugs can extend their tubular mouthparts forward in front of the body to impale prey and suck out the contents.
Their nymphs go through dramatic color changes as they mature. Early stages are oval with black heads and mostly red abdomens. Third-stage nymphs become a patchwork of black, brown, orange, red, and white. By the fifth stage, they’re black, cream, and tan with orange or red markings. If you spot these colorful nymphs on your plants, leave them be.
Rough Stink Bug
Rough stink bugs in the genus Brochymena are another beneficial group. Adults are shield-shaped and range from about 7/16 to 3/4 inch long, mottled in browns and grays with flecks of black, white, and sometimes orange or yellow. Their coloring mimics tree bark so closely that they’re easily overlooked when resting on branches. The “rough” name comes from the toothed or serrated edge on the front margin of the thorax.
These bugs live primarily in trees and shrubs, where they prey on caterpillars, leaf beetle larvae, sawfly larvae, and other soft-bodied insects. They also feed harmlessly on leaves, seeds, and shoots of various broadleaved plants. Because they spend most of their time in the canopy rather than on garden vegetables, most people never notice them.
How Stink Bugs Defend Themselves
The characteristic smell that gives the entire family its name comes from scent glands on the underside of the thorax. When disturbed, stink bugs release a cocktail of chemicals consisting primarily of long-chain alkanes, aldehydes, and esters. The odor is often described as a mix of cilantro and burnt rubber, and it serves two purposes: deterring predators and signaling nearby stink bugs to disperse.
Crushing or vacuuming stink bugs triggers this release, which is why squashing one indoors leaves a lingering smell. The odor is harmless but persistent.
Bugs Commonly Mistaken for Stink Bugs
Two insects regularly get misidentified as stink bugs. The western conifer seed bug is the most common lookalike. It’s about 3/4 inch long, mottled dark brown, and has a triangular shield shape where the wings overlap near the thorax. However, it’s longer and narrower than a true stink bug and has distinctive leaf-like flares on its hind legs. It also displays a dark “X” pattern across the back and alternating dark and light markings along the body’s outer edges. Like brown marmorated stink bugs, western conifer seed bugs enter homes in fall, which adds to the confusion.
Squash bugs are another common misidentification. They’re flatter and more elongated than stink bugs, typically dark gray or brown, and found almost exclusively on squash and pumpkin plants. While they belong to a related family, they don’t produce the same intense odor when handled.
Keeping Stink Bugs Out of Your Home
Mechanical exclusion is the most effective strategy. Seal cracks around windows, doors, siding, utility pipes, and behind chimneys with silicone or silicone-latex caulk. Repair or replace damaged window and door screens. These entry points are how brown marmorated stink bugs find their way into wall voids and attic spaces each autumn.
For bugs already inside, the simplest approach is sweeping or flicking them into a container of soapy water. Cut the top off a straight-sided plastic container, fill the bottom quarter with water mixed with a teaspoon of liquid soap, and hold it beneath the bug. They drop readily when disturbed. Vacuuming also works, though the bugs will make your vacuum smell. A useful workaround: slip a knee-high stocking over the outside of the vacuum tube, secure it with a rubber band, then stuff the stocking into the tube. Bugs get captured in the stocking before reaching the canister. After vacuuming, empty the stocking into soapy water.
Spraying stink bugs with water outdoors will dislodge them temporarily, but they typically return. In the garden, removing weedy overwintering hosts like wild mustard, Russian thistle, and little mallow reduces local populations over time.