The kudzu bug, Megacopta cribraria, is an invasive insect species that has spread throughout the southeastern United States since its discovery in 2009. While they are significant agricultural pests of legumes, their mass aggregation in the fall often alarms homeowners. Kudzu bugs do not possess the ability to bite or sting humans or household pets.
The Answer: Kudzu Bug Interactions with Humans
The confusion about kudzu bugs biting often stems from their habit of crawling on people when they aggregate near homes. This behavior, combined with the bug’s defensive reaction, can be misinterpreted as a bite or sting. Like other shield bugs, kudzu bugs release a noxious, foul-smelling chemical when disturbed or crushed.
This defense mechanism involves the secretion of chemical compounds, including aldehydes, which cause direct physical irritation upon contact with human skin. This irritation is commonly reported as dermatitis, a rash, or a hive-like reaction, often mistaken for an insect bite. The fluid released can also leave temporary brown stains on skin, fabrics, carpets, and household surfaces. The pungent odor can linger if multiple bugs are crushed indoors.
Identifying the Kudzu Bug and Its Lifecycle
Kudzu bugs are small, measuring approximately 4 to 6 millimeters in length, giving them a pea-sized appearance. They have a distinctive, rounded, and broad body that is olive-green or brownish with dark speckles. As “true bugs,” they possess piercing-sucking mouthparts, which they use exclusively to feed on plant sap from their host plants.
Native to Asia, the insect was first documented in Georgia and quickly established itself as an invasive species across the South. Kudzu bugs are primarily pests of leguminous plants, such as kudzu vines, soybeans, and wisteria. Their life cycle is typically bivoltine, meaning they produce two generations annually.
The adult bugs are most noticeable in the late fall when cooler temperatures signal the need to find winter shelter. They cease feeding and begin to aggregate on warm, sun-exposed surfaces of structures. They then crawl into crevices and voids to overwinter. Once inside a home, the bugs enter a dormant state and do not feed or reproduce until the spring.
Controlling Kudzu Bugs Around the Home
The most effective strategy for managing kudzu bugs involves exclusion, preventing them from entering the home. This is best done in the late summer or early fall before the insects search for overwintering sites. Homeowners should inspect and seal any gaps or cracks around window frames, door sweeps, utility penetrations, and the foundation.
All window and door screens must be checked for holes and properly seated to eliminate potential entry points. If kudzu bugs enter the living space, physical removal is the preferred method. Crushing them will result in the release of the foul odor and the staining of surfaces.
Vacuuming the bugs is highly recommended, but it is best to use a shop vacuum or place a nylon stocking over the end of the hose. This prevents the insects from passing through the motor and fouling the appliance. After vacuuming, the contents should be immediately sealed in a bag and disposed of, or placed in hot, soapy water to kill the insects.
The use of broad-spectrum insecticides inside the home is discouraged. Dead insects can still release their odor and stain materials, and aggregation behavior means many will still enter. For heavy infestations on the exterior of a building, a perimeter application of a residual pyrethroid insecticide may be used, following all label directions.