The brown marmorated stink bug, an invasive insect, often seeks warm shelter inside homes, signaling a seasonal nuisance. These shield-shaped insects are known for their defensive reaction: releasing a potent, foul-smelling chemical spray when disturbed. While primarily a deterrent to predators, accidental contact with this spray can lead to several unpleasant sensory and physical effects for humans.
The Defensive Mechanism and Its Components
The noxious spray is released from specialized scent glands located on the underside of the bug, specifically on the thorax and abdomen. When the insect feels threatened, such as when it is picked up or crushed, it can expel this liquid mixture as a defense. The unpleasant odor originates from a complex blend of organic compounds, primarily aldehydes and hydrocarbons. The main components identified are trans-2-decenal and trans-2-octenal, which belong to the aldehyde chemical group. These chemicals are the source of the persistent, pungent scent that can linger on surfaces and skin.
Sensory and Physical Effects of the Spray
The immediate and most noticeable effect of the spray is the distinct, strong odor it produces. Many people describe this smell as intensely pungent or acrid, while others note a specific resemblance to the herb cilantro. The odor can be quite nauseating, especially in enclosed spaces.
Direct contact with the fluid on the skin can cause localized, temporary irritation or a mild form of dermatitis. Although the spray is non-toxic to humans, the chemicals can be irritating, particularly to sensitive individuals. Some people may develop a temporary, minor rash or redness at the site of contact.
Contact with the delicate mucous membranes of the eyes results in a much more intense reaction. If the fluid gets into the eyes, the aldehydes can induce a chemical burn injury known as irritant contact keratitis. This condition causes pain, redness, and a defect in the corneal epithelial layer, requiring prompt medical attention.
If the spray is accidentally ingested or touches the mouth, it causes an immediate, burning sensation and an unpleasant chemical taste. While serious poisoning is not a risk, the immediate discomfort is significant and acts as a powerful warning against consumption. Inhaling the odor in high concentrations may also trigger allergic symptoms, such as a runny nose, tearing, or asthma attacks in sensitive individuals.
Immediate Steps for Cleaning and Relief
The first action after contact with the spray should be to thoroughly wash the affected skin area with soap and warm water. Because the chemical compounds are oily, repeated washing may be necessary to fully remove the persistent scent. It is important to avoid rubbing your eyes or face until the area is completely clean.
For clothing or surfaces that have been sprayed, a simple solution of diluted white vinegar or a paste made from baking soda and water can help neutralize the odor. These household items can absorb or break down the chemical compounds responsible for the smell. Specialized odor neutralizers can also be used effectively on fabrics and upholstery.
If the spray has entered the eyes, immediately rinse them thoroughly with a large amount of clean water for several minutes. Due to the risk of corneal injury from the chemical components, seek medical attention promptly after rinsing. Anyone experiencing persistent eye pain, significant redness, respiratory distress, or signs of an allergic reaction should consult a healthcare provider.