Stink bugs are a common sight in many homes, particularly as cooler weather approaches. These shield-shaped insects seek refuge indoors during late summer and fall. Their presence often leads to questions about managing them, including whether water can eliminate them. This article explores how stink bugs breathe and if they can drown.
How Stink Bugs Breathe
Stink bugs, like all insects, possess a respiratory system distinct from that of mammals. They do not have lungs; instead, air enters their bodies through small external openings called spiracles, located along their thorax and abdomen. These spiracles act as muscular valves that regulate airflow and minimize water loss.
Once air enters through the spiracles, it travels into a network of internal tubes known as tracheae. These tracheae branch repeatedly, becoming smaller until they reach individual cells. Oxygen diffuses directly from these tubes into the tissues, while carbon dioxide moves out through the same system. The insect’s hard exoskeleton provides protection for this respiratory network, but the spiracles remain points of access for gases.
The Drowning Process
Stink bugs can drown, although the mechanism differs from how larger animals suffocate in water. When a stink bug is submerged, water can enter its spiracles, blocking the flow of air into the tracheal system. This obstruction prevents oxygen from reaching the insect’s cells and impedes the removal of carbon dioxide, leading to suffocation.
However, plain water may not immediately cause drowning due to surface tension. The waxy exterior of a stink bug and the natural surface tension of water can create a barrier, trapping a thin layer of air around the insect’s body, potentially preventing water from fully entering the spiracles. Despite this, if fully submerged, stink bugs will eventually succumb; they typically drown within 20 to 40 seconds when their breathing holes are effectively blocked.
Using Water for Stink Bug Control
Given their susceptibility to drowning, water can be a component of stink bug control, but its effectiveness is enhanced with certain modifications. Plain water is often inefficient because surface tension allows stink bugs to float or remain at the surface without immediate submersion. Their waxy cuticles also help them repel water.
To overcome this, adding liquid dish soap or detergent to water is a widely recommended and effective method. Soap acts as a surfactant, breaking down the water’s surface tension. This allows the water to more easily penetrate the stink bug’s waxy coating and enter its spiracles, leading to quicker suffocation. A common solution involves mixing warm water with liquid dish detergent, such as combining 32 ounces (1 liter) of warm water with 3/4 cup (180 ml) of liquid dish soap.
For practical application, stink bugs can be gently swept or flicked into a jar or bucket filled with this soapy water solution. Alternatively, a spray bottle filled with soapy water can be used to directly spray the insects. The soap breaks down their waxy outer layer, leading to dehydration in addition to suffocation. This method is considered one of the least messy and most effective ways to manage stink bugs without causing them to release their defensive odor.