K
Species Profile

Kudzu Bug

Megacopta cribraria

Small bug, big swarms-beware kudzu's hitchhiker.
SIMON SHIM/Shutterstock.com

Kudzu Bug Distribution

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Invasive Species
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Found in 7 countries

🇨🇳 China 🇮🇳 India 🇯🇵 Japan 🇰🇷 South Korea 🇹🇼 Taiwan 🇹🇭 Thailand 🇻🇳 Vietnam
Macro Shot of a Kudzu Bug

At a Glance

Wild Species
Also Known As Bean plataspid, Kudzu stinkbug, Plataspid stinkbug
Diet Herbivore
Activity Diurnal
Lifespan 8 years
Status Not Evaluated
Did You Know?

Adults are only ~4-6 mm long, noticeably smaller and rounder than many common stink bugs (Pentatomidae).

Scientific Classification

The kudzu bug is a small sap-feeding true bug (Hemiptera) best known as an invasive agricultural nuisance where it has spread beyond its native range. It aggregates in large numbers and can be a pest of legumes, notably kudzu and soybean.

Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Hemiptera
Family
Plataspidae
Genus
Megacopta
Species
cribraria

Distinguishing Features

  • Small, broad, somewhat squarish/oval-bodied true bug
  • Often appears olive-brown to mottled, with a shield-like profile
  • Strong tendency to form dense aggregations on host plants and structures
  • Sap-feeding on legumes; commonly associated with kudzu (Pueraria) and soybean

Physical Measurements

Length
0 in (0 in – 0 in)

Appearance

Primary Colors
Green Brown
Secondary Colors
Tan Black Cream
Skin Type Hard, chitinous exoskeleton with dense punctation; slightly matte/waxy; shield-like scutellum expanded to cover most of dorsal abdomen (Plataspidae).
Distinctive Features
  • Adult body length typically about 0.4-0.6 cm; compact, strongly convex, oval/rounded tortoise bug profile.
  • Scutellum greatly enlarged and plate-like, covering nearly the entire dorsal surface (key Plataspidae trait).
  • Surface densely punctate (cribrate), producing a granular, dusty look at close range.
  • Short antennae and overall smaller size than most Pentatomidae stink bugs; lacks prominent "shoulders" common in many pentatomids.
  • Legs relatively short; overall silhouette appears hemispherical rather than flat, angular, or broad-shouldered.
  • Often seen in large aggregations on kudzu and soybean; adults mass on buildings as a nuisance during dispersal/overwintering.
  • Sap-feeding hemipteran pest; invasive in the southeastern United States and associated with legume yield impacts rather than medical harm.
  • Can emit an odor when disturbed, but is taxonomically Plataspidae (not a typical Pentatomidae 'stink bug').

Sexual Dimorphism

Sexual dimorphism is subtle. Females are typically slightly larger and more broadly rounded posteriorly, especially when gravid; males average a bit smaller and may appear more tapered, with reliable separation usually requiring examination of terminal abdominal/genital characters.

♂
  • Slightly smaller average body size; posterior end often appears more tapered.
  • Terminal abdominal/genital structures diagnostic under magnification (external differences subtle).
♀
  • Slightly larger average body size; abdomen often more rounded, especially when egg-filled.
  • Terminal abdominal segments broader; genital characters confirm sex under magnification.

Did You Know?

Adults are only ~4-6 mm long, noticeably smaller and rounder than many common stink bugs (Pentatomidae).

Despite the nickname, it's a "plataspid" (Family Plataspidae), not a typical stink bug family member-its body is more turtle-shaped and compact.

It was first detected in the continental U.S. in 2009 (near Atlanta, Georgia) and spread rapidly through the Southeast as an invasive pest.

It specializes on legumes: kudzu (Pueraria montana) is a major host, but soybean (Glycine max) is the key crop at risk.

Adults mass-aggregate on light-colored surfaces (homes, cars) in cool seasons, becoming a nuisance even when they aren't feeding.

It carries essential gut symbionts that help it thrive on plant sap; females pass the symbionts to offspring using capsule-like deposits near eggs.

Feeding can reduce soybean vigor and yield, making it both an agricultural and nuisance pest in invaded regions.

Unique Adaptations

  • Obligate bacterial symbiosis: Megacopta cribraria depends on gut symbionts for nutrition on a sap diet; mothers provision offspring with symbiont-containing capsules so nymphs can establish the bacteria early.
  • Compact, shield/turtle-like form (Plataspidae): The rounded profile and expanded body margins help protect legs and underside while feeding and during crowding in dense aggregations.
  • Aggregation tolerance: Physiological and behavioral tolerance for crowding supports enormous clusters that reduce individual risk and aid survival during overwintering.
  • Legume specialization: Mouthpart function and host-finding behavior are tuned to legumes (notably kudzu and soybean), enabling rapid population growth where hosts are abundant.

Interesting Behaviors

  • Mass aggregation: Adults cluster by the hundreds to thousands on buildings, tree trunks, and other vertical surfaces, especially during seasonal movements (e.g., seeking overwintering sites).
  • Sap-feeding on legumes: Uses piercing-sucking mouthparts to tap phloem in kudzu, soybean, and other legumes; feeding can cause leaf stippling, reduced vigor, and stress responses in host plants.
  • Seasonal dispersal flights: Adults disperse to locate hosts and later move to sheltered overwintering sites; these movements drive the sudden "invasion" of homes and structures in affected areas.
  • Defensive odor: Like many true bugs, it can release a noticeable defensive smell when disturbed, though its overall shape and taxonomy differ from Pentatomidae stink bugs.
  • Symbiont management: Adults (especially females) actively maintain and transmit required gut bacteria to offspring-an unusual, highly specialized behavior among insects.

Cultural Significance

In the southeastern United States, the kudzu bug (Megacopta cribraria) is a home‑invading, invasive Hemipteran pest tied to kudzu. It became a public topic and a teaching example of plant–insect invasions and Plataspidae vs. Pentatomidae.

Myths & Legends

No well-documented traditional folklore or ancient mythology is known specifically for Megacopta cribraria; instead, its "story" is largely modern and historical.

In parts of the U.S., the name "kudzu bug" links two invasive species: kudzu, a long-time symbol of Southern landscape change, and the newer nuisance bug that seems to arrive with kudzu.

After the Kudzu Bug (Megacopta cribraria) was found in the U.S. in 2009, it spread across the Southeast. People told 'biblical' swarm stories when bugs gathered on houses each autumn, a seasonal gathering.

Conservation Status

NE Not Evaluated

Has not yet been evaluated against the criteria.

Population Unknown

Life Cycle

Birth 26 nymphs
Lifespan 8 years

Lifespan

In the Wild
2–12 years
In Captivity
2–5 years

Reproduction

Mating System Promiscuity
Social Structure Aggregation Group
Breeding Pattern Transient
Fertilization Internal Fertilization
Birth Type Internal_fertilization

Adults aggregate on host plants and mate via internal fertilization. The mating system is best described as promiscuous, with both sexes likely mating multiple times; females lay egg masses on foliage and provide no parental care beyond oviposition.

Behavior & Ecology

Social Congregation Group: 1000
Activity Diurnal
Diet Herbivore Kudzu (Pueraria montana var. lobata) stem/petiole sap (primary host plant in invaded and native-range literature)
Seasonal Hibernates

Temperament

Gregarious; strong tendency to aggregate on hosts and overwintering surfaces
Non-aggressive to conspecifics; crowding tolerated in dense clusters
Defensive when disturbed: readily drops, disperses, and releases noticeable odor
Most individuals aggregate; some remain solitary when host quality is low.

Communication

none documented for Megacopta cribraria in peer-reviewed literature
chemical defense secretion (characteristic 'stink' odor) used in disturbance/alarm contexts; species-specific components incompletely resolved
aggregation likely mediated by chemical cues (host odors + conspecific cues); definitive M. cribraria aggregation pheromone not fully characterized
contact/tactile cues: clustering and repeated body contact help maintain dense resting aggregations
maternal provisioning behavior: females deposit symbiont-containing capsules near eggs; nymphs acquire symbionts by feeding on them A key social transmission route

Habitat

Agricultural/Farmland Plantation Suburban Urban Woodland Deciduous Forest Shrubland Grassland +2
Biomes:
Temperate Forest Temperate Grassland Tropical Dry Forest
Terrain:
Plains Hilly Valley Coastal Riverine
Elevation: Up to 4921 ft 3 in

Ecological Role

Herbivorous phloem/vascular sap-feeding insect strongly associated with legumes; invasive agricultural pest where introduced.

Acts as a major consumer of legume plant sap (notably kudzu and soybean), transferring plant-derived energy into higher trophic levels as prey for generalist predators/parasitoids Potential (limited/inconsistent) suppression of kudzu growth via chronic sap removal on kudzu patches (often outweighed by crop damage risk in agroecosystems) Agricultural disservice: reduces soybean vigor/yield through sustained vascular feeding and heavy aggregation pressure (documented in soybean pest-impact studies following establishment in the southeastern U.S.)

Diet Details

Other Foods:
Kudzu vine sap Soybean sap Legumes

Human Interaction

Domestication Status

Wild

Megacopta cribraria, the kudzu bug, is a wild, not-domesticated Plataspidae insect with no history of being bred by people. People mainly know it as a pest: native to Asia and invasive in the U.S. Southeast since 2009. It damages crops like soybean, gathers on buildings to overwinter, and is tracked by pest programs.

Danger Level

Low
  • Nuisance household infestations: adults aggregate on and enter buildings while seeking overwintering sites; can occur in very high numbers.
  • Odor and staining: when disturbed or crushed, can release odor and leave stains on surfaces (typical of many true bugs).
  • Minor irritation: incidental contact may cause mild skin/eye irritation in sensitive individuals; medically significant bites/stings are not characteristic of this species.
  • Indirect risk: promotes increased insecticide use in agricultural settings, increasing potential for human exposure if pesticides are misused.

As a Pet

Not Suitable as Pet

Legality: Kudzu Bug (Megacopta cribraria) is not usually a pet. But keeping, moving, or releasing this invasive farm pest can be illegal across states. Only keep live bugs with official permits for research or education.

Care Level: Experienced

Purchase Cost: Up to $20
Lifetime Cost: Up to $50

Economic Value

Uses:
Agricultural pest (soybean and other legumes) Invasive species management cost driver (monitoring, insecticides, extension/outreach) Research model for invasion ecology and insect-bacterial symbiosis
Products:
  • None (no established beneficial commercial products); economic impact is primarily negative via crop damage and nuisance aggregation

Relationships

Predators 5

Kudzu bug egg parasitoid wasp Paratelenomus saccharalis
Egg parasitoid wasp Ooencyrtus nezarae
Spined soldier bug Podisus maculiventris
Assassin bug
Assassin bug Reduviidae
Orb-weaver spider
Orb-weaver spider Araneidae

Related Species 4

Kudzu bug
Kudzu bug Megacopta punctatissima Shared Genus
Black bean plataspid Brachyplatys subaeneus Shared Family
Shield-backed bug Coptosoma scutellatum Shared Family
Plataspid bug Plataspis sulcata Shared Family

Ecological Equivalents 4

Animals that fill a similar ecological role in their ecosystem

Brown marmorated stink bug Halyomorpha halys Sap-feeding hemipteran that, like Megacopta cribraria, is an invasive landscape and structural nuisance noted for mass aggregation on buildings. Both species are broad-scale pests in human-modified habitats, with adults readily dispersing to overwintering sites.
Southern green stink bug Nezara viridula A major legume and soybean pest that overlaps strongly with M. cribraria in crop systems. Both use piercing-sucking mouthparts to feed on plant fluids, can reach high field densities, and cause yield and quality loss in soybean through sustained feeding pressure.
Redbanded stink bug Piezodorus guildinii Another key soybean-feeding hemipteran. Ecologically similar due to a shared host crop (soybean), the same feeding guild (piercing–sucking), and overlapping management practices (field scouting thresholds and insecticide-based suppression during outbreaks).
Soybean aphid Aphis glycines Both feed on the sap of legumes, especially soybean plants, and can reach outbreak levels that require similar pest control. Megacopta cribraria is a small plataspid bug about 4–6 mm long that often aggregates; soybean aphids are soft-bodied and form colonies.

The kudzu bug is one of the biggest agricultural pests of beans and legumes. However, many people know them by the name “globular stink bug.” But they go by many names like bean plataspid and lablab bug.

These tiny olive-colored bugs originate from India and China, but they were first documented in the USA in 2009. Researchers believe these kudzu bugs traveled on a plane from Asia to Atlanta and spread ferociously across Georgia, South Carolina, and North Carolina.

If the kudzu bug only feeds on kudzu, it can be pretty beneficial, but when they set their sites on other crops like soybean plants, they can cause mass destruction.

Although they are not dangerous to people or houseplants, they can become a big problem if they enter a home.

Kudzu Bug Scientific Name

The kudzu bug’s scientific name is Megacopta cribraria, and they belong to the order Hemiptera. This order consists of a group of large insects, with about 7500 species around the world and 1,700 species in the British Isles alone.

While most of the species in this order differ from each other, all of them have piercing mouthparts that they use to suck out the juices of plants or blood from animals. In addition, their mouthparts are lodged inside a beak (rostrum), primarily held underneath their bodies when they are not using it.

These pests are members of the Family Plataspidae, usually oval in shape, with a small head, large scutellum, U-shaped abdomens, and forewings larger than their bodies. In addition, there are around 500 species belonging to the Plataspidae family worldwide.

Appearance: How To Identify the Kudzu Bug

Macro Shot of a Kudzu Bug 2

Another macro shot of a kudzu bug.

©SIMON SHIM/Shutterstock.com

The kudzu bug has a hard exoskeleton and is usually brown-olive green in color, covered in brown speckles. It is very hard to misidentify these tiny pets because they have a unique oval shape that is broader at the bottom than the top. In addition, they have very distinguished plates on their backs.

Furthermore, like many true bugs, kudzus have piercing mouthparts, which they use to suck out the sap or other fluids from plants and animals. An adult can grow to q/4 inch in length, similar to the size of a lady beetle.

Habitat: Where to Find the Kudzu Bug

Kudzu bugs disperse in large numbers in the early summer months after wintering in tree bark, cracks, garden debris, and doorframes of homes. However, these insects usually inhabit and live off kudzu and soybean plants near residential areas.

In addition, they are attracted to light-colored surfaces like white house siding, white cars, and white clothes!

Diet: What Does the Kudzu Bug Eat?

Kudzu bugs cause extensive damage by feeding on kudzu plants, soybean fields, and other legumes. But they don’t just feed off these plants, they also lay their eggs on them, and their nymphs will start to feed their juices as soon as they hatch.

Feeding on the plants’ nutrients, foliage, and moisture severely damages the crop. In addition, these pesky bugs also feed off peanuts, peas, wisterias, and garden beans.

Life Cycle of the Kudzu Bug

The kudzu bug is a hemimetabolous insect, meaning they complete its life cycle via incomplete metamorphosis. These pests develop in three stages:

Egg

These insects complete one to two generations each year. First, the female will lay her eggs on kudzu leaves, wisteria, or soybean plants. Then, she disperses them in two side-by-side rows, each containing around 15 eggs.

Underneath the kudzu bug eggs are capsules of endosymbiotic bacteria, so once the nymphs hatch, they need to consume this to help digest the host plant.

Nymphs

The kudzu bug nymph phase consists of 5 stages. These nymphs have a hairy appearance and differ in color from a pale orange, olive green, or light brown. kudzu nymphs take approximately 6 to 8 weeks to develop into adults.

Adults

Kudzu bug adults will take refuge in homes during winter, often flocking to the attics for warmth. But, they will inhabit leaf litter or tree bark if they can’t find a cozy home. Then, as the weather starts to warm up, these adults will resume feeding and reproduction.

Adult kudzu bugs can live for around 23 to 77 days, depending on nutritional intake, location, and temperature.

Is the Kudzu Bug Dangerous to Humans?

These bugs don’t bite humans, but they secrete a substance that can irritate people’s skin, which is often confused for a bite.

If this pest does cause skin irritability, it will leave a stain, which will subside after a few days. So, be on the lookout for these tiny bugs in the fall, as they tend to seek shelter in homes when cold weather arises.

Prevention: How to Get Rid of the Kudzu Bug

Unfortunately, there are very few ways to prevent these tiny pests from invading your home. However, there are precautions you can take that might help. For example, kudzu bugs generally infest areas with a lot of food sources, so removing any Kudzy vines surrounding your property could help reduce the likelihood of infestation.

In addition, these bugs also like to feed on wisterias and legumes like beans or peas, so if you have any of these plants in close proximity to your home, getting rid of them can help.

However, preventing kudzu bugs from getting into your home might be more difficult. You can start by meticulously sealing all the gaps on the exterior of your house, especially around the doors and windows. In addition, inspect the vents, pipe openings, and foundation for any cracks or crevices.

How to Get Rid of Kudzu Bugs

There are several ways of getting rid of kudzu bugs; they include:

Removing the Bugs Manually

If you find kudzu bugs in your home, you can vacuum them up with a hose attachment. However, you need to get rid of them while they are still in the bag by putting them in the freezer or submerging them in hot, soapy water, which will kill these pests.

But, whatever you do, do not squish these insects; they will secrete hideous odor and leave a stain on your surfaces.

Spraying Adults

There are several household spray pesticides that will terminate kudzu bugs. However, it might be hard to reach the bugs with these pesticides as they generally congregate high on exterior walls.

When spraying kudzu bugs, you need to use pyrethrin-based pesticides like:

  • Bifenthrin
  • Lambda-cyhalothrin
  • Permethrin

In fact, pesticides ending in a “thrin” contain pyrethrin-based products.

While these pesticides aren’t harmful to people and pets, they are toxic to fish and other aquatic wildlife, so do not pour them down the drain or any place running off into storm drains.

Spraying Nymphs

While spraying adult kudzu bugs is effective, researchers believe spraying the nymphs is even more effective. Commercial soybean farmers prefer this method and tend to use bifenthrin as their pesticide of choice.

So, if you have wisteria or green beans in your garden, give them a good spray during nymph hatching season, which occurs in late May, or early June.

Hire a Professional

For inexperienced gardeners, it might be best to call an exterminator. These trained professionals have all the know-how and tools to terminate those pesky kudzu bugs.

Unfortunately, you may have to call them out more than once because, usually, kudzu bug infestations require several weekly treatments before you see effective results.

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Sources

  1. Kidadl / Accessed November 29, 2022
  2. Orkin / Accessed November 29, 2022
  3. Wikipedia / Accessed November 29, 2022
Chanel Coetzee

About the Author

Chanel Coetzee

Chanel Coetzee is a writer at A-Z Animals, primarily focusing on big cats, dogs, and travel. Chanel has been writing and researching about animals for over 10 years. She has also worked closely with big cats like lions, cheetahs, leopards, and tigers at a rescue and rehabilitation center in South Africa since 2009. As a resident of Cape Town, South Africa, Chanel enjoys beach walks with her Stafford bull terrier and traveling off the beaten path.
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