Pennsylvania homeowners are no strangers to the unwelcome presence of stink bugs.
These shield-shaped insects have a knack for emitting a foul odor if you disturb or crush them—definitely not the houseguest you want.
The main culprit in Pennsylvania is the brown marmorated stink bug, an invasive species from Asia. You’ll spot them by their mottled brown coloring and those distinctive white bands on their antennae.
Stink bugs tend to make themselves known in the fall, hunting for warm places to ride out the winter.
They squeeze in through the smallest cracks, sometimes turning up in the oddest corners of your house.
While they won’t bite you or chew through your walls, they’re still a major nuisance.
Some, like the brown marmorated stink bug, are also notorious for damaging crops and gardens—a headache for Pennsylvania’s farmers and gardeners.
Over the past few years, new varieties have started showing up, too.
The kudzu bug is one example, with its tough shell and plant-piercing beak.
If you want to keep stink bugs out of your home or protect your garden, it helps to know which types are around and what makes them tick.
1. Brown Marmorated Stink Bug
The Brown Marmorated Stink Bug (BMSB) (Halyomorpha halys) is an invasive pest first spotted in the United States in 2001, though it turns out specimens were collected as early as 1998 in Allentown, Pennsylvania.
Originally from Eastern Asia, it’s now all over Pennsylvania.
People sometimes call them shield bugs—the body shape is a dead giveaway, looking almost like a medieval shield.
Their coloring is a mottled brownish-gray, and if you look closely, you’ll notice alternating light and dark bands on their antennae.
Physical Characteristics:
- Length: 1/2 to 3/4 inch
- Color: Mottled brown-gray
- Shape: Shield-like
- Distinctive white bands on antennae and legs
BMSBs have been spreading across eastern Pennsylvania in recent years.
The name comes from the strong odor they release if you disturb or squash them—honestly, it’s hard to forget once you’ve smelled it.
In the fall, these bugs start searching for overwintering sites.
They’ll slip into homes and buildings, looking for somewhere warm to hunker down.
That’s why you suddenly find them indoors as soon as the weather turns chilly.
BMSB hibernation usually stretches from October into early spring, and they’re pretty much inactive until things warm up again.
They’re bad news for Pennsylvania agriculture, too. By piercing plant tissues and sucking out sap, they damage fruits, veggies, and ornamentals.
If you’re a homeowner, you’ll mostly see them inside during the colder months, trying to stay cozy.
2. Green Stink Bug
The Green Stink Bug (Chinavia hilaris) is hard to miss, thanks to its bright green color.
These bugs grow up to about ¾ inch long, and their bodies are almost as wide as they are long—sort of a rounded shield look.
Adults have six legs and two pairs of wings, so yes, they can fly.
Most are solid green, but you might spot some with yellow or black markings along the edges.
Like its relatives, Chinavia hilaris gives off a pretty nasty smell if it feels threatened or gets crushed.
It’s a decent defense against predators, if not against annoyed humans.
Life Cycle:
- Adults show up in early summer (usually June)
- One generation per year
- Activity in fruit trees drops off by mid to late summer
Green Stink Bugs are considered an agricultural pest and can go after a wide range of crops.
They use their piercing-sucking mouthparts to feed on plant juices, which can cause real headaches for:
- Fruits
- Vegetables
- Field crops
- Ornamental plants
If you’ve got a home garden, watch out—these bugs especially like ornamentals and fruit trees.
They’ll pierce developing fruits, sometimes leaving them dimpled or deformed, which isn’t great for yield or looks.
The Green Stink Bug is native to North America and found throughout the Midwest.
In Pennsylvania, they’re around from spring through fall, peaking in the summer months.
3. Spined Soldier Bug
The Spined Soldier Bug (Podisus maculiventris) is a bit of an outlier—it’s actually considered beneficial in Pennsylvania.
You can spot it by the pointed shoulders and shield-shaped body, plus a sort of spear-like projection on each side of its pronotum.
Unlike most stink bugs, the Spined Soldier Bug is a predator.
It’s been recorded eating over 100 species of pest insects, so it’s a real asset in gardens and on farms.
They’re not too picky—they’ll eat all sorts of caterpillars and love beetle and moth larvae in particular.
The Spined Soldier Bug is found all over North America, and it’s pretty common in Pennsylvania.
You could confuse it with other stink bugs, but its predatory habits set it apart.
Key characteristics:
- Shield-shaped body
- Pointed shoulder spines
- Brown to grayish color
- Feeds on pest insects, not plants
If you’re a gardener, it’s worth learning to recognize these helpful bugs so you don’t accidentally lump them in with the troublemakers.
Unlike the brown marmorated stink bug, which is a crop pest, the Spined Soldier Bug is a natural pest controller.
In Pennsylvania gardens, these predatory stink bugs help keep other insects in check, which means less need for chemical sprays.
4. Rough Stink Bug
The Rough Stink Bug (Brochymena quadripustulata), sometimes called the Four-humped Stink Bug, is a native species in Pennsylvania.
It gets its name from the rough, textured look of its body.
Color-wise, it ranges from brown and gray to almost blackish, with stripes and some orange spots. It’s medium-sized, about 1/2 to 3/4 inch long.
Physical Characteristics:
- Rough, bumpy body surface
- Four humps on the thorax
- Mottled brown/gray color
- Orange markings on the sides
- Pointed “shoulders”
Unlike its invasive cousin, the Brown Marmorated Stink Bug, this one is native to North America.
Brochymena species have actually taken a hit since the invasives showed up.
The Rough Stink Bug has a bit of a mixed reputation. Some call it a plant pest, while others say it’s beneficial since it sometimes preys on other insects. It’s a bit of both, really.
You can tell them apart from the Brown Marmorated by the rough texture and the markings.
The BMSB has one white band on the hind legs and bands on the antennae, which you won’t see on the Rough Stink Bug.
In Pennsylvania, these bugs are often found on tree bark, where their coloring helps them blend in.
They’re most active when it’s warm, but don’t be surprised if one sneaks into your house during colder spells.
5. Dusky Stink Bug
The Dusky Stink Bug (Euschistus tristigmus) is pretty widespread in Pennsylvania.
It’s got a dark brown color and really sharp shoulder projections—kind of a giveaway if you’re trying to ID it.
This one’s about 10-12mm long when it’s fully grown. Like most stink bugs, the body is shield-shaped, but those sharp shoulder points make it stand out.
The life cycle’s fairly typical: eggs hatch into nymphs, which go through five stages before becoming adults.
The nymphs are smaller, wingless, and often look a bit rounder with different color patterns that shift as they grow.
Dusky stink bug nymphs can look pretty different from the adults, but they keep that classic shield shape.
These bugs are agricultural pests, feeding on fruits and crops.
They use their piercing mouthparts to suck out plant juices, which can lead to dimpling, discoloration, and misshapen produce.
Like other stink bugs, Euschistus tristigmus gives off a pretty foul odor if threatened.
It’s a decent defense against predators, though not much comfort for anyone who accidentally steps on one.
Dusky stink bugs are in the same genus as a few other brownish stink bug species with similar looks and habits.
They’re often mistaken for the brown marmorated stink bug, which is understandable given how much they resemble each other.
6. One-Spotted Stink Bug
The One-Spotted Stink Bug (Euschistus variolarius) pops up pretty much everywhere in Pennsylvania.
It’s part of the Euschistus genus, which has a bunch of brownish stink bugs that look a lot like the brown marmorated stink bug.
If you’ve seen one, you know the look: those pointed shoulders and the single spot on their underside are dead giveaways.
They’re usually about ¾ inches long, and honestly, they’re almost as wide as they are long—kind of chunky for a bug.
You’ll find these stink bugs on a wild mix of plants, both wild and cultivated.
They’re not picky eaters, which is probably why farmers keep an eye out for them.
Physical Characteristics:
- Length: Up to ¾ inch
- Color: Light brown to tan
- Distinctive feature: Pointed shoulders
- Underside: Features the signature “one spot“
- Wings: Adults can fly
Adults are most active when it’s warm out and will take flight if they need to.
Like their stink bug cousins, they let off that unmistakable smell if you bother them or accidentally squish one. Not exactly pleasant, but it does the job, keeping predators away.
If you’re growing anything edible, it’s a good idea to check for these pests during the season.
The One-Spotted Stink Bug can mess with crops by feeding on plant tissues and fruits.
7. Brown Stink Bug
The Brown Stink Bug (Euschistus servus) is a classic shield-shaped bug you’ll see across Pennsylvania.
Their color runs from brown to grayish-brown, with a speckled look that lets them disappear against tree bark or dirt.
Adult Brown Stink Bugs are about 10-15mm long and have those little teeth along their shoulders—that’s how you can tell them apart from the others.
Physical Characteristics:
- Color: Brown to grayish-brown
- Size: 10-15mm long
- Body: Shield-shaped, pretty tough-looking
- Antennae: 5 segments
- Unique feature: Teeth-like bumps on the shoulders
People sometimes mix these up with the invasive Brown Marmorated Stink Bug, but Euschistus servus is actually native here.
They don’t have those white bands on their antennae like the invaders do.
They’re part of the Pentatomidae family and, yep, the Euschistus genus, which is full of similar brownish species.
And, of course, they’ve got that trademark stink when threatened or crushed, thanks to special glands.
Not something you forget if you’ve ever squished one by accident.
Brown Stink Bugs in Pennsylvania stick to sucking plant juices from fruits, veggies, and even your favorite ornamental plants.
Their straw-like mouths pierce right through plant tissue to get at the sap.
Farmers and gardeners aren’t exactly fans—they can damage crops like soybeans, corn, and all sorts of fruits, leaving behind dimples, scars, and weird colors on produce.
8. Twice-Stabbed Stink Bug
The Twice-Stabbed Stink Bug (Cosmopepla lintneriana) is tiny but hard to miss if you spot one in Pennsylvania or just about anywhere in North America.
Up in Alberta, some folks even call it the “Wee Harlequin Bug”—which is kind of adorable, honestly.
They’re only about 5-7mm long, so much smaller than the other stink bugs around.
But what they lack in size, they make up for with their bold colors and patterns.
Appearance:
- Black body with red or orange markings
- Two bright red spots on the back (hence “twice-stabbed”)
- Classic shield shape
- Black and white checkered edge
The Twice-Stabbed Stink Bug is all over Pennsylvania. You might see them crawling around in leaf litter as soon as spring warms up.
Like the rest, they give off a nasty smell if you bother them—nature’s way of saying “back off.”
They stick to feeding on plant juices, but honestly, they don’t do nearly as much damage as some of the bigger agricultural pests.
Gardeners might catch these little beauties on mint, raspberries, or various weeds.
They’re most noticeable when it’s warm, from late spring through early fall.
They’re not a huge problem like the brown marmorated stink bug, but they’re definitely an interesting part of Pennsylvania’s insect scene.
9. Predatory Stink Bug
The Predatory Stink Bug (Podisus placidus) is a beneficial insect found in Pennsylvania.
Unlike its plant-eating relatives, this species is actually helpful to gardeners and farmers.
These bugs are part of the Pentatomidae family and have the classic shield-shaped body that stink bugs are known for.
They typically grow to about ¾ inches in length, with bodies nearly as wide as they are long, and adults can fly with their wings.
What really sets Podisus placidus apart is its predatory lifestyle.
They’ve got short beaks and sucking mouth parts—perfect tools for hunting other insects instead of nibbling on plants.
Diet and Hunting Habits:
- Feeds on caterpillars and beetle larvae
- Attacks many common garden pests
- Uses its beak to inject digestive enzymes into prey
- Sucks out the liquefied contents of its victims
Their role as agents of biological control in Pennsylvania gardens and farms can’t be overstated.
They’re like tiny, natural pest managers, helping keep populations of destructive insects in check—no chemicals needed.
The nymphs (immature forms) of Podisus placidus look quite different from adults but are just as predatory.
They shed their skins several times before reaching adulthood, changing up their looks with each molt.
These helpful bugs belong to a wider group of predators that affect green stink bugs and other pest species in Pennsylvania’s ecosystem.
So, if you spot one of these predatory stink bugs in your garden, maybe just let them do their thing—they’re on your side.
