When certain insects are disturbed or killed, they can release a strong, unpleasant odor. These smells act as a defense mechanism. Understanding why these bugs produce such odors and how to identify them can help manage their presence around your home and garden, and guide you in handling them without triggering their defensive scent.
The Science Behind the Odor
The foul smells emitted by some insects are a biological defense. These odors result from specific chemical compounds stored within specialized glands in the insect’s body. When threatened, these compounds are released into the air.
The exact chemical composition varies among species, but common compounds include aldehydes, alkanes, and esters. For instance, the brown marmorated stink bug releases trans-2-octenal and trans-2-decenal, which some describe as smelling like cilantro or coriander. These chemicals not only repel threats but can also act as alarm pheromones, signaling danger to other insects of the same species.
Identifying Common Stink Bugs
Several common insects are known for their distinctive odors when disturbed. Stink bugs, belonging to the family Pentatomidae, are perhaps the most recognized for this trait. They are typically shield-shaped, measuring about 1/2 to 3/4 inch long, and can be brown, green, or black. The brown marmorated stink bug, an invasive species, has a mottled brown body with lighter bands on its antennae and darker bands on its wings.
Boxelder bugs, Boisea trivittata, are another common offender, identifiable by their black bodies with distinctive red or orange markings, including three stripes behind the head. These insects are about 1/2 inch long and their wings often lie flat, forming an ‘X’ shape on their backs. Boxelder bugs frequently aggregate in large numbers near boxelder, maple, and ash trees, often seeking shelter indoors as temperatures drop. Their nymphs are initially bright red, gradually developing black markings as they mature.
Squash bugs, Anasa tristis, are brownish and flattened, typically measuring between 1/2 and 3/4 inch long. They have wings that form an ‘X’ shape when folded and primarily feed on plants in the cucurbit family, such as squash and pumpkins. Both adults and nymphs emit a foul odor when crushed.
Managing Stinky Bugs
To avoid the release of unpleasant odors, it is generally best to handle these bugs without crushing them. Physical removal methods are often effective and prevent the activation of their defensive chemicals. For instance, sealing potential entry points into your home, such as cracks around windows and foundations, can prevent bugs like stink bugs and boxelder bugs from entering.
Using a vacuum cleaner can be an effective way to remove these insects without directly crushing them. It is advisable to use a vacuum with a bag that can be immediately sealed and disposed of outdoors to contain any lingering odors. For outdoor management or small numbers indoors, sweeping bugs into a container for release away from the home is another non-lethal option.
For boxelder bugs, a simple solution of dish soap and water can be sprayed directly on them, which breaks down their outer layer and leads to dehydration. This method can kill them without producing the strong odor associated with crushing. Regularly cleaning up yard debris and maintaining screens on windows and doors can also help reduce the presence of these odor-producing insects.