Homeowners often worry that eliminating the invasive Brown Marmorated Stink Bug (BMSB) may worsen the problem. This pest seeks sheltered indoor spaces to overwinter and releases a pungent odor when disturbed. The question is whether a dead stink bug, or the act of killing it, releases a chemical signal that attracts more of its kind. A dead stink bug does not produce the signal necessary to attract a large group, but crushing it releases a different compound entirely.
How Stink Bugs Communicate and Aggregate
Stink bugs, including the BMSB, rely on chemical communication for many life functions, primarily using compounds called pheromones. The process of gathering in large numbers, known as aggregation, is driven by a specific chemical blend called the aggregation pheromone. This pheromone is released by living individuals, primarily males, to call both males and females to a suitable spot for feeding, mating, or shelter.
This powerful signal is a two-component blend of stereoisomers. The release of this airborne compound often occurs when the insect finds a protected place, such as a structure’s wall voids, signaling that this is a safe overwintering site. The aggregation pheromone is the true attractant, produced actively by a live bug, not passively by a dead one.
The Effect of Dead Bugs: Aggregation vs. Alarm Signals
The idea that a dead stink bug attracts others is largely a misunderstanding of the different chemical signals the insect produces. A living bug stops the active release of the aggregation pheromone upon death, meaning the corpse does not function as a beacon for others to gather. The strong, foul odor associated with killing a stink bug is actually an alarm pheromone, a defense mechanism meant to deter predators.
This defensive secretion is a volatile mixture of aldehydes, primarily trans-2-octenal and trans-2-decenal, released when the insect is crushed or physically threatened. Instead of attracting more stink bugs, this alarm signal functions as a warning to nearby individuals, causing them to disperse from the area. This odor is chemically distinct from the aggregation pheromone and does not serve to call a group together.
Why Removal is Still Necessary
Even though dead stink bugs do not emit the aggregation pheromone, prompt and complete removal remains a wise practice for household sanitation. Allowing dead insects to accumulate can create an attractive environment for secondary, less noticeable pests. The decomposing bodies of stink bugs may draw scavengers, such as dermestid beetles or other carrion feeders, into the home.
This subsequent pest problem can be more persistent and difficult to manage than the initial stink bug invasion. Removing the dead insects also eliminates a visual cue that could signal a history of successful entry to newly arriving BMSBs. Good hygiene and the absence of insect debris help to maintain a clean environment and reduce the likelihood of attracting a different set of unwanted guests.
Effective Disposal Methods
The best way to handle stink bugs is to remove them without triggering the release of the defensive alarm odor. To avoid the foul smell, it is recommended to use methods that capture the insect without crushing its body.
One effective non-contact method is to use a bag-type vacuum cleaner, provided the bag can be immediately sealed and disposed of outside. Another simple technique involves gently sweeping the bugs into a container of soapy water, which will drown them and neutralize the odor.
The most long-term action is prevention. Focus on sealing potential entry points into the structure, such as cracks around windows and foundation gaps, to prevent the overwintering invasion entirely.