Stink bugs are shield-shaped insects that earned their common name from the emission of a foul-smelling chemical when disturbed or crushed. This odor comes from specialized glands on the abdomen, which release a pungent fluid that acts as a deterrent to predators. The species of greatest concern across North America is the invasive Brown Marmorated Stink Bug (BMSB), Halyomorpha halys, which originated in East Asia.
Damage to Crops and Ornamental Plants
The most significant and costly damage caused by stink bugs occurs in agricultural settings, where they feed on a wide variety of high-value crops. The insects use piercing-sucking mouthparts, known as a stylet, to insert into plant tissues and draw out fluids. While feeding, the stink bug injects digestive enzymes that break down cell material and cause localized tissue death. This combination leads to severe defects in fruits and vegetables.
Feeding damage on fruit, such as apples and peaches, results in surface pitting, scarring, and sunken areas, often described as “catfacing” due to the resulting rough, irregular deformation. The internal tissue beneath these feeding sites becomes corky and brown, making the produce unmarketable as a fresh product. Field crops are also heavily impacted, with stink bugs feeding on developing kernels of corn and seeds within soybean pods. This feeding action leads to shriveled or aborted seeds and can cause the “stay green” effect in soybeans, where damaged plants fail to mature properly late in the season.
The high-value nature of affected crops means that even low populations of stink bugs can cause substantial economic losses. For example, damage to apple and stone fruit orchards in the Mid-Atlantic United States has resulted in millions of dollars in crop loss. Ornamental plants and shade trees are also susceptible, displaying stippling or necrotic spots on leaves where the insects have fed.
Risks to Human Health and General Comfort
For people, the harm posed by stink bugs is primarily one of extreme nuisance, rather than a direct health hazard. Stink bugs do not bite or sting humans, as their mouthparts are designed solely for piercing plant tissue and cannot penetrate human skin. They are not known to transmit any diseases to people or pets, nor do they possess venom or toxins.
The primary human discomfort is associated with the defensive odor they release when threatened, handled, or crushed. This smell, which some describe as musty, acrid, or cilantro-like, comes from a mixture of chemical compounds, including aldehydes. While the chemicals are pungent, they are generally considered non-toxic to human health. In rare instances, individuals with high sensitivities or allergies may experience mild reactions, such as temporary contact dermatitis on the skin or respiratory irritation from inhaling the concentrated odor.
Structural and Aesthetic Impact on Property
Stink bugs pose no structural threat to homes or buildings, as they are not wood-boring insects and do not consume household materials. They are nuisance pests that seek shelter inside structures to survive the winter. In the late summer and fall, large numbers of adult stink bugs congregate on the sunny sides of buildings, searching for small cracks and openings to enter wall voids and attics. Once inside, they enter a dormant state, but fluctuating temperatures may cause them to become active and emerge into living spaces.
The harm they cause indoors is purely aesthetic and related to mass nuisance. When high numbers of bugs are accidentally crushed or killed, their defensive secretions can leave behind brown or yellowish stains on walls, curtains, carpets, and furniture. This staining is difficult to remove and is accompanied by the persistent, foul odor released by the defensive chemical. The insects do not reproduce indoors, meaning the infestation is seasonal.