Description and Life Cycle
Stink bugs are insects in the order Hemiptera. They are flying insects with distinctive shield-shaped bodies, and, in fact, are often called shield bugs. Over 200 species of stink bug are present in the United States, including both herbivorous and predatory species.
Stink bugs get their common name from the strong-smelling fluid that they secrete from glands on the sides of the thorax when they're threatened. The odor is meant to make the stink bug unpalatable to its predators, but many birds and other insects are able to tolerate the fluid and still prey on the stink bug.
Although stink bugs are well known for their odor-producing ability, many other species in the Hemiptera order have the same ability.
Herbivorous species of stink bug have sharp mouth parts that they use to pierce plant tissues and suck fluid from inside the plants. Species that feed on fruits inject digestive juices into the fruit, causing discolored soft spots.
Beneficial Stink Bugs
Although herbivorous stink bugs are often garden and agricultural pests, some stink bug species are considered beneficial. Predatory species feed on caterpillars, aphids, beetle larvae and other insects that damage plants, and are therefore welcome garden inhabitants.
The rough stink bug (Brochymena arborea) is one such beneficial species; it is about an inch long, and its mottled color mimics the bark of trees on which it lives. The spined soldier bug (Podisus maculiventris) is another beneficial predator; it's smaller than the rough stink bug and has a more uniform gray-green color.
Brown Marmorated Stink Bug
The brown marmorated stink bug (Halyomorpha halys) is a native of Asia that has become widespread in the United States. It causes significant damage to fruit, vegetables and other agricultural crops, and it can be a problem in the garden as well. In cool weather, it's attracted to warm areas near buildings, and it may migrate inside homes.
This species is a mottled brown color and less than 3/4 inch long. It can be differentiated from other stink bugs, including the similar rough stink bug, by the light-colored bands on its antennae.