Stink Bugs

In North America, more than 200 species in 64 genera.

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Green stink bug on a leaf
The green stink bug (Chinavia hilaris, formerly Acrosternum hilare) is one of many species of stink bugs. Like other stinkbugs, the folded wings form an X pattern on the back.
Susan Ellis, Bugwood.org
Family

Pentatomidae (stink bugs) in the order Hemiptera (true bugs)

Description

Like most true bugs, stinkbugs (in family Pentatomidae) have membranous wings that fold flat along the back when at rest (often creating an X pattern on the back), and mouthparts joined into a strawlike structure used for piercing and sucking. Members of the stink bug family are generally oval or shield-shaped. The head is rather small. The antennae have 5 segments. The pronotum (shoulderlike section between head and wings) is generally large, and the scutellum (triangular section at the base of the folded wings, pointing away from the head) is also quite large. Coloration, patterning, and shape varies with species. Some are drab brown, gray, or tan, others leaf green, and others bright red or orange with contrasting black patterns.

Size

Length: to about ¾ inch (varies with species).

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Tan stink bug on dead leaves
Stink Bug
Stink bugs are shield-shaped insects that can smell very bad. Many are camouflaged with tan or green.

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Juvenile predatory stink bug on leaf with inchworm prey
Predatory Stink Bug (Nymph)
Predatory stink bugs in genus Apoecilus prey on other insects. This juvenile bug was eating an inchworm that, apparently, had been chewing on the leaf.

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Photo of green stink bug nymphs
Green Stink Bug Nymphs
Green stink bug fourth-instar (fourth-stage) nymphs have reddish markings and yellow stripes.

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Eggs and nymphs of brown marmorated stink bug
Brown Marmorated Stink Bug Eggs and Nymphs
The brown marmorated stink bug (Halyomorpha halys), a native of southeast Asia, was discovered in Pennsylvania in 1998, apparently having hitched a ride on shipping crates. A crop and fruit-tree pest, it is spreading across North America.
Habitat and conservation

As with many plant-feeding insects, these bugs are usually found on or near their food plants. Many stink bugs are generalists and thus not limited to one type of plant. Most stink bugs can fly well, so they can be found nearly anywhere, including inside homes. They are often attracted to lights at night. When harassed or crushed, most stink bugs emit a foul odor that is a defense against predation.

Foods

Like many other true bugs (such as cicadas, aphids, squash bugs, and leafhoppers), stink bugs have strawlike mouthparts adapted for sucking nutrients. Most feed on plants, and some are crop pests. A few prey on other insects.

image of Stink Bugs Distribution Map
Distribution in Missouri

Statewide.

Status

Common.

Life cycle

Adults overwinter in sheltered places. In spring they mate, and the females lay rows of closely spaced, barrel-shaped eggs on the undersides of leaves. Hatchlings tend to stay near the plants they hatched on. They grow and molt through various immature stages (nymphs). They emerge from their final molt as winged, sexually mature adults. Stink bugs that are full adults by late fall overwinter.

Human connections

Some stink bugs are crop and garden pests. In late fall when they are seeking shelter, overwintering stink bugs sometimes enter homes, to the dismay of the human occupants.

Ecosystem connections

Stink bugs take plant nutrients into their bodies and are then eaten by other animals. Keep this in mind if you are considering insecticides, for birds and other insect-eaters can be harmed indirectly by consuming poisoned insects. Various parasitic flies and other insects also feed on stink bugs.