Wood bugs, commonly found in gardens and damp outdoor spaces, often spark curiosity. These small, segmented creatures are a frequent sight when overturning rocks or logs, prompting questions about their nature. Understanding them clarifies their environmental role and potential concerns.
Understanding Wood Bugs: Not What You Think
Many people mistakenly identify wood bugs as insects, but they are actually terrestrial crustaceans, making them more closely related to crabs and lobsters than to beetles or ants. These invertebrates belong to the order Isopoda. Their bodies are typically oval-shaped and flattened, covered by a hard, segmented exoskeleton that provides protection.
Wood bugs have seven pairs of legs and two pairs of antennae, which they use to sense their surroundings. Some species, like the common pill bug (Armadillidium vulgare), can roll into a tight, defensive ball when disturbed. This behavior, earning them the name “roly-polies,” protects their softer undersides from predators. Other types, like the common sow bug (Porcellionides pruinosus), cannot fully roll into a ball but share similar physical traits.
Where They Live and What They Eat
Wood bugs thrive in consistently moist, dark environments, as their bodies are not well-suited to dry conditions. They are frequently found under rocks, decaying logs, leaf litter, and garden debris, where humidity levels remain high. These creatures also inhabit areas beneath potted plants, within compost piles, and in the upper layers of rich garden soil. Their preference for damp, secluded spots prevents them from drying out.
As detritivores, wood bugs play a significant role in the decomposition process within ecosystems. Their diet primarily consists of decaying organic matter, such as dead leaves, rotting wood, and other decomposing plant material. By consuming and breaking down dead vegetation, they recycle nutrients back into the soil. This process contributes to soil health and fertility, making them important members of the garden ecosystem.
Are They Harmful? Dispelling Myths
Despite their appearance, wood bugs are generally harmless to humans and household pets. They do not bite, sting, or carry diseases that affect people or animals. Concerns about them damaging healthy living plants are unfounded, as their primary food source is dead or decaying organic matter.
Wood bugs might occasionally nibble on tender seedlings or soft fruits in contact with the soil, but this usually occurs when preferred food sources are scarce. They are not considered significant agricultural pests and rarely cause widespread damage to crops or garden plants. Their presence often indicates a healthy soil environment rich in organic material. Wood bugs serve a beneficial purpose by aiding in the breakdown of organic material, enriching the soil, and contributing to ecosystem health.