What Does a Stink Bug Look Like?

Scientists describe stink bugs in several different ways. Some scientists call them “large, oval-shaped insects.” Other scientists call them “shield-shaped insects.”

image of a stink bug

Adult stink bugs can reach almost 2 cm in length. They are almost as wide as they are long. Their legs extend from the sides, so this makes the adult bugs look even larger than they really are.

Immature stink bugs, called nymphs, are very tiny when they hatch from their eggs. As they develop, the nymphs molt or shed their skin five times. Each time it molts, the nymph becomes larger. By the last molt, the nymphs are almost as large as adult stink bugs.

Adult stink bugs are good fliers and fold their wings on top of their body when they land. Nymphs do not have fully developed wings. The wings appear when the nymph becomes an adult. Fully developed wings are a way to identify adult stink bugs.

Depending on the species, adult stink bugs might be green, brown or grayish in color. The nymphs are often a different color from the adults. In some cases, the nymphs can change colors as they develop.

As its name suggests, the adult southern green stink bug is a green insect. The scientific name is Nezara viridula (L). Adults normally measure 12 to 13 mm in length. Newly hatched nymphs are black. They become green as they develop into adults.

Many species of stink bugs are brown-colored insects. The brown marmorated stink bug (Halyomorpha halys) is a brownish stink bug. This stink bug has lighter bands on the antennae and darker bands on the wings.

Nymphs of the brown marmorated stink bug are yellow and red. As they grow, the yellow fades to white. They have bright red eyes during the nymph stage of their life cycle.

Even though stink bugs are garden pests, they often enter homes to find a place to spend the winter. Homeowners are often upset to find these large insects on the walls or windows of their home.