Stink bugs are a common sight in homes and gardens. These insects are known for their distinctive appearance and ability to release an unpleasant odor when disturbed. Understanding their physical characteristics is important for accurate identification. This article helps identify stink bugs by their unique features and differentiate them from look-alikes.
The Hallmarks of a Stink Bug
Stink bugs possess a distinctive shield-like or broadly triangular body shape, wider at the front and tapering towards the rear. Adult stink bugs typically measure between 0.5 to 0.75 inches (12 to 19 mm) in length and are generally almost as wide as they are long.
Their coloration varies but commonly includes shades of brown, green, or gray, often displaying mottled patterns that help them blend into their surroundings. A large, triangular scutellum, a hardened plate located on their back between the wing bases, extends significantly down their back. Stink bugs have six legs and a pair of segmented antennae, which can be about half the length of their body. When at rest, their wings are folded flat over their back, with the membranous tips often overlapping.
Common Species and Their Variations
The Brown Marmorated Stink Bug (BMSB), an invasive species from Asia, is one of the most frequently encountered. This species is characterized by its mottled brown appearance. A distinguishing feature of the BMSB is distinct white bands on the last two segments of its antennae. The BMSB also has alternating light and dark bands visible along the exposed edges of its abdomen.
The Green Stink Bug is typically bright green in color. Some green stink bugs may also feature a thin orange or yellowish border along their body margins. Their antennae often have black bands on the last three segments.
Avoiding Misidentification: Stink Bugs vs. Look-Alikes
Squash Bugs are sometimes confused with stink bugs due to their similar brownish coloration and ability to emit an odor. However, squash bugs have a more elongated and flatter body shape, lacking the broad shield-like form of a true stink bug. They also display orange stripes on the edges of their abdomen.
Leaf-footed Bugs can be mistaken for stink bugs but possess a narrower, more slender body. Many leaf-footed bugs have a distinctive, leaf-like expansion on their hind legs, which is absent in stink bugs. While both stink bugs and certain beetles might appear somewhat similar in shape, beetles belong to a different insect order and have hardened forewings (elytra) that form a protective shell. Stink bugs, classified as “true bugs,” have piercing-sucking mouthparts and forewings that are partially hardened and partially membranous.