When the brown marmorated stink bug feels threatened, disturbed, or crushed, it deploys an intense, unpleasant odor as a defensive mechanism. The odor is secreted from glands on its abdomen and thorax, releasing a foul, potent liquid to deter predators. This defensive release raises the question of whether the potent smell poses any real danger to human health.
The Chemical Composition of the Odor
The distinctive “stink” is primarily composed of various chemical compounds, mostly belonging to the aldehyde group. The major components identified in the defensive secretion are trans-2-octenal and trans-2-decenal. These aldehydes are volatile organic compounds (VOCs) that easily become vapors or gases at room temperature, which allows the odor to quickly spread through the air. The mix of these and other compounds gives the secretion its pungent, lingering aroma, sometimes described as a strong cilantro or coriander scent. The chemical compounds also serve a multifunctional role for the insect, acting as a deterrent while exhibiting antifungal and antibacterial properties.
Assessing Systemic Health Risks and Toxicity
Despite the noxious nature of the smell, the defensive secretion is not considered systemically poisonous or lethal to humans or pets in typical exposure scenarios. The concentration of aldehydes released into the air by a few stink bugs is extremely low, making serious internal damage highly unlikely. Stink bugs do not possess venom, nor do they transmit diseases to humans, which further reduces the overall medical risk. The primary health concern associated with the odor is one of nuisance and temporary discomfort, rather than any long-term or widespread bodily harm. Ingestion, while not poisonous, can cause mouth irritation or an upset stomach if a large number of the insects are consumed.
Immediate Symptoms of Acute Exposure
Direct or acute exposure to the defensive fluid can cause immediate, localized reactions. Upon close contact or inhalation, the volatile compounds may irritate the mucous membranes in the eyes, nose, and throat. This localized irritation can lead to symptoms like a runny nose, teary or itchy eyes, and temporary respiratory discomfort, such as coughing. The chemical fluid can also cause contact dermatitis, which is a mild skin irritation or rash, if the residue touches the skin. Individuals with pre-existing respiratory conditions, such as asthma, may experience a temporary worsening of their symptoms due to the irritant nature of the odor.
Eliminating the Residual Odor
Once the stink bugs have been removed, the lingering odor can be mitigated with practical steps, since the smell is not permanent. Because the odor is caused by volatile compounds, ventilating the area by opening windows and using fans is an effective first step to allow the chemicals to dissipate.
For surfaces where the residue may have settled, cleaning with soapy water or a vinegar solution can help break down and remove the chemical remnants. It is important to exercise caution when using a vacuum cleaner to remove the bugs, as crushing them inside the machine will release the odor and can cause the vacuum to smell for a period of time. When handling the insects, gently sweeping them into a container of soapy water is a preferred method to prevent the release of the defensive fluid.