A red stink bug is not one particular species. The description may refer to a true stink bug with red markings, a brightly colored nymph, or a similar-looking insect from another family. Redbanded and red-shouldered stink bugs are plant-feeding pests, while the red-and-black two-spotted stink bug is a beneficial predator. Boxelder bugs, milkweed bugs, and bordered plant bugs are also frequently misidentified as stink bugs. Correct identification requires examining the insect’s body shape, markings, antennae, legs, and preferred plants before deciding whether control is necessary.
What Does a Red Stink Bug Look Like?
True stink bugs usually have a broad, shield-shaped body, six legs, segmented antennae, and a triangular plate on the center of the back. Their red coloring may cover the entire upper body or occur as bands, spots, stripes, shoulders, wings, or abdominal markings.
Identification Features
A red or red-marked stink bug may have:
- A broad, shield-shaped adult body
- Red, orange, black, green, or white markings
- A large triangular plate called the scutellum
- Overlapping wings forming an X-like pattern
- Piercing-sucking mouthparts beneath the body
- Alternating colors along the abdominal edge
- Long, segmented antennae
- Scent glands that release an odor
- A body approximately 1/3 to 3/4 inch long
Color is highly variable. Two members of the same species may appear red, orange, tan, or yellow, making body patterns more useful than color alone.
Common Red and Black Stink Bug Species
Several true stink bugs have noticeable red or reddish-orange markings. Some feed on crops, while others consume insects and benefit gardens. Identifying their diet and mouthpart thickness can help determine whether they should be controlled.
Two-Spotted Stink Bug
The two-spotted stink bug, Perillus bioculatus, is one of the most recognizable red-and-black stink bugs. It is a beneficial predator that attacks Colorado potato beetles and other soft-bodied insects.
Identification features include:
- Black head and legs
- Red, orange, yellow, or cream body
- Two black spots on the shoulders
- A black keyhole or Y-shaped mark on the back
- Rounded shoulders
- A thick predatory beak
- Adult length of approximately 8–10 millimeters
Both adults and nymphs can be red and black. UC Integrated Pest Management describes adults as black with contrasting reddish-orange, pale green, white, or yellow coloring.
Because it feeds on crop pests, this species should normally be protected rather than eliminated.
Red-Shouldered Stink Bug
The red-shouldered stink bug may refer to Thyanta custator in eastern and central North America or related Thyanta species in western regions.
Adults are commonly green with a narrow red or pink band across the shoulders. However, some individuals become brown during autumn, and certain forms appear mostly black with red markings.
Look for:
- Green, brown, or black body
- Narrow red or pink shoulder band
- Red marks on the scutellum in some forms
- Relatively small shield-shaped body
- No long abdominal spine between the hind legs
- Red or reddish feet in some individuals
The nymphs may be tan or black with several thin red bands across the abdomen.
Redbanded Stink Bug
The redbanded stink bug, Piezodorus guildinii, is a significant soybean and legume pest. Despite its name, the adult is primarily green rather than red.
Identification features include:
- Light-green shield-shaped body
- Red, purple, orange, or dark band across the shoulders
- Adult length of approximately 0.3–0.4 inch
- Oval-shaped nymphs
- A fixed spine projecting from the abdomen between the hind legs
- Preference for soybeans, peas, beans, and other legumes
The abdominal spine separates it from the similar red-shouldered stink bug. UF/IFAS Extension provides a detailed comparison of these two species.
Harlequin Stink Bug
The harlequin bug, Murgantia histrionica, has bold red, orange, yellow, white, and black markings. It is a plant-feeding stink bug commonly found on cabbage, kale, broccoli, turnips, and other mustard-family plants.
Its pattern is usually symmetrical, with contrasting patches across the wings and back. Both adults and nymphs can damage plants by removing sap.
Why Are Baby Stink Bugs Red and Black?
Many stink bug nymphs display bright red, orange, black, and white coloring even when the adults are plain brown or green. Their appearance changes after each of five molts.
Red Stink Bug Nymph Identification
Red-and-black nymphs may have:
- A rounded or oval body
- Six black legs
- Red, orange, or black antennae
- White or yellow spots
- No functional wings
- Developing wing pads in later stages
- Clustering behavior after hatching
Brown marmorated stink bug nymphs are orange-red and black immediately after hatching. Green stink bug nymphs may also display red, black, green, and white markings. Predatory two-spotted stink bug nymphs are commonly red and black.
A red baby stink bug cannot be identified reliably by color alone. Host plant, shape, pattern, and later developmental stages provide additional evidence.
Red Stink Bugs vs. Similar Red and Black Bugs
Not every shield-like or foul-smelling red insect belongs to the stink bug family. Several common lookalikes have longer bodies and different wing patterns.
Red Stink Bug vs. Boxelder Bug
| Feature | Red Stink Bug | Boxelder Bug |
| Body | Broad and shield-shaped | Long, narrow, and oval |
| Coloring | Variable red patterns | Black with thin red-orange lines |
| Back | Large triangular scutellum | Red lines form an X on wings |
| Typical plant | Varies by species | Boxelder and maple trees |
| Indoor behavior | Some overwinter indoors | Frequently gathers on sunny buildings |
Boxelder bugs often enter homes in large groups during autumn. They are nuisance insects but cause little indoor damage.
Red Stink Bug vs. Bordered Plant Bug
Bordered plant bugs in the genus Largus are sometimes called red or black stink bugs. Adults are dark gray or black with orange-red borders, while nymphs may have bright-red abdomens and black wing pads.
Their bodies are more elongated than true stink bugs. California species such as Largus californicus are common around gardens and buildings but belong to the family Largidae.
Red Stink Bug vs. Milkweed Bug
Large milkweed bugs have long orange-red and black bodies with an X-shaped wing pattern. Small milkweed bugs display a pale or white spot on each wing.
They feed mainly on milkweed seeds and have narrower bodies than true stink bugs.
Red Stink Bug vs. Red-Shouldered Bug
The red-shouldered bug, Jadera haematoloma, is not the same insect as the red-shouldered stink bug. It has a narrow dark body with reddish shoulders and commonly gathers around goldenrain trees and soapberry plants.
The similar common names create frequent identification errors.
Red and Blue Stink Bugs in Australia
A metallic blue-and-red or blue-and-orange insect in Australia may be a hibiscus harlequin bug, Tectocoris diophthalmus. It belongs to the jewel bug family, Scutelleridae, which is closely related to stink bugs.
Adults can appear metallic blue, green, orange, or red. They have a large shield covering most of the abdomen and commonly feed on hibiscus-family plants. Their appearance differs significantly between sexes and developmental stages.
Are Red Stink Bugs Poisonous?
Red stink bugs are not poisonous to touch, and their color does not indicate unusual danger. Most plant-feeding species rarely bite people. Predatory stink bugs can puncture skin with their beak if trapped or handled roughly.
Possible Risks
- Defensive odor when disturbed
- Mild irritation in unusually sensitive individuals
Avoid handling unidentified true bugs with bare hands. Use a container or gloves when moving them.
Do Red Stink Bugs Have Red Blood?
Stink bugs do not have red, iron-based blood like humans. Their circulatory fluid is called hemolymph and is generally clear, yellowish, greenish, or pale.
A red stain from a crushed insect may come from body pigments, defensive fluid, or recently consumed plant material rather than red blood.
What Do Red Stink Bugs Eat?
Diet depends on the species. Plant-feeding stink bugs use their beaks to remove fluids from fruit, seeds, stems, and leaves. Predatory species inject digestive saliva into other insects before consuming them.
Plant-Feeding Species
Redbanded and red-shouldered stink bugs may feed on:
- Soybeans
- Beans and peas
- Alfalfa
- Cotton
- Corn
- Sorghum
- Fruit
- Seeds
- Wild legumes
Predatory Species
Two-spotted stink bugs may consume:
- Colorado potato beetle larvae
- Leaf beetle larvae
- Caterpillars
- Other soft-bodied crop pests
This difference is why an unknown red stink bug should be identified before pesticides are applied.
Signs of Plant Damage
Plant-feeding red stink bugs can injure crops throughout the growing season. Both nymphs and adults insert their mouthparts into developing tissue.
Common Damage
- Puncture marks on fruit
- Discolored or sunken spots
- Misshapen vegetables
- Damaged seeds
- Empty or shriveled soybean pods
- Aborted young fruit
- Wilted shoots
- Reduced crop quality
Redbanded stink bugs are particularly important soybean pests. Adults are green with a reddish shoulder band and have a distinctive abdominal spine.
How to Get Rid of Red Stink Bugs
First determine whether the insect is a plant pest, harmless visitor, or beneficial predator. Removing two-spotted stink bugs could increase populations of caterpillars and beetle larvae.
Garden Control
- Hand-pick plant-feeding adults and nymphs.
- Drop collected bugs into soapy water.
- Remove egg masses from leaf undersides.
- Control weeds that serve as alternate hosts.
- Use row covers before plants flower.
- Inspect field and garden edges regularly.
- Encourage parasitoid wasps and other predators.
- Apply an insecticide only when damage justifies it.
- Follow the label for the crop and target species.
Large agricultural infestations should be evaluated using crop-specific scouting thresholds rather than color or the presence of a few bugs.
Indoor Removal
Red-and-black bugs found indoors are often boxelder bugs or bordered plant bugs rather than stink bugs.
Remove them by:
- Capturing individual insects with a cup.
- Vacuuming larger groups.
- Repairing screens.
- Sealing cracks around doors and windows.
- Closing gaps beneath siding and roof edges.
- Avoiding indoor pesticide foggers.
Crushing the insects may release odor or stain walls and fabrics.
FAQs
Is there one species called the red stink bug?
No. “Red stink bug” is an informal description applied to several true stink bugs, their nymphs, and unrelated lookalikes.
What is a black and red stink bug called?
A true black-and-red species may be the two-spotted stink bug. However, boxelder bugs, milkweed bugs, and bordered plant bugs can look similar.
Are red stink bug nymphs harmful?
Some feed on plants, while others are beneficial predators. Identification should be confirmed before control.
Do black and red stink bugs bite?
Most plant-feeding species rarely bite. Predatory stink bugs may puncture skin when handled but do not seek people as food.
Should I kill a red-and-black two-spotted stink bug?
Usually not. The two-spotted stink bug is a beneficial predator that helps control Colorado potato beetles and other crop pests. NC State Extension identifies it by its two shoulder spots and keyhole-shaped back marking.