Stinkbug, the common name for a family of insects. There are thousands of species, found in most parts of the world. Stinkbugs are so named because they secrete a foul-smelling liquid that is repulsive to most predators. Most stinkbugs are dull in color, usually gray or brown, but some are such colors as black (often with red or orange markings), green, or blue. They generally range from 1/4 to 1/2 an inch (6 to 13 mm) in length. Some species are serious pests of such crops as cotton and cabbage; others are beneficial because they feed on other harmful insects. One of the best-known North American species, the harlequin cabbage stinkbug, is destructive to plants of the mustard family.

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StinkbugsStinkbugs secrete a foul-smelling liquid
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What Makes Stinkbugs True Bugs?

Like all true bugs, stinkbugs have no chewing mouthparts. Instead, they have tubelike beaks called rostrums attached to their heads. The rostrum has four thin, sharp needles in it.

Many stinkbugs sink their needles into plants. They use their needles to suck up the sap or juice that the plants use to transport and store food. Some stinkbugs stick their beaks into other insects and suck their body fluids. When not feeding, stinkbugs hold their beaks underneath their bodies between their front legs.

Like most true bugs, a stinkbug has two pairs of wings. The back wings are so thin you can almost see through them. The front wings are thick and tough at the base and very thin at the tips. When a stinkbug rests, the tips of its front wings cross, forming what looks like an “X.”

How Is a Stinkbug Put Together?

A stinkbug, like all insects, has a body that is divided into three sections. These sections are the head, the thorax (THAWR aks), and the abdomen. A tough shell, or exoskeleton (ehk soh SKEHL uh tuhn), protects the bug’s entire body.

In addition to its rostrum, a stinkbug has two large eyes on its head. These eyes are compound eyes. They are made up of many separate lenses. In between the eyes are two long feelers, or antennae (an TEHN ee). A stinkbug uses its antennae to touch and to “pick up” scents.

A stinkbug’s middle section is the thorax. Its legs are attached to its thorax. If the stinkbug has wings, they are also attached to the thorax.

The abdomen is a stinkbug’s hind section. Here is where you will find most of a stinkbug’s spiracles (SPY ruh kuhlz), or breathing holes. The bug’s digestive and reproductive systems are also in its abdomen.

Why Are Some Stinkbugs Called Shield Bugs?

Many true bugs have hard, flat covers on their backs that look like shields. These covers are called scutella (skyoo TEHL uh). They help protect, or shield, the bugs. That’s why these bugs are also called shield bugs. A scutellum is shaped like a triangle or a shield. Some stink bugs and many related true bugs have scutella so big that they cover most of their backs.

Stinkbugs come in a variety of colors. Some are all green. Some are all brown. Still others are black with white, yellow, orange, or red markings. Some stinkbugs have bright colors. Others have dull colors.

Does a Stinkbug Really Stink?

A stinkbug gives off a very bad smell if it is bothered. The smell comes from a stinky liquid that flows from two glands on the bug’s thorax. Once released, the odor remains on whatever the stink bug touches. To most predators, a stinkbug tastes as bad as it smells. Many birds spit out stinkbugs right after biting into them. However, other birds don’t seem to mind a stinkbug’s taste.

What Do Stinkbugs Feed On?

Most kinds of stinkbugs suck the juices of plants. Some kinds suck the body fluids of insects. Others feed on both plants and insects. Plant-sucking stinkbugs feed on the juices of young fruits and seeds. Some also suck the sap from plants as well as the nectar from flowers. Green stinkbugs often suck on crops like soybeans, rice, and tomatoes.

Some stinkbugs can greatly damage a farmer’s crops. But others can be helpful to farmers. The helpful stinkbugs kill other insects that do more harm to plants than they do themselves. Such insects include certain types of beetles and caterpillars and even some other stinkbugs.

How Do Stinkbugs Find Mates?

Some stinkbugs use special odors to attract mates. Smelling the odors helps partners find each other. Some kinds of stinkbugs also attract mates with sound. They rub their legs or wings against their bodies to make noises similar to those of crickets. Mates are drawn to the sounds.

After mating, a female stinkbug lays batches of eggs. Often she lays them in neat rows of 12 or 14 eggs each. The eggs are usually laid on plant leaves. Stinkbug eggs look like tiny barrels. The colors of the eggs depend on the type of stinkbug that laid them. Green stinkbugs, for example, lay yellow to green eggs that turn pink or gray.

In some species, a mother stinkbug closely guards her nymphs (NIHMFS), or young, after they hatch. If the mother senses danger, she moves herself between the enemy and the nymphs. Then she acts as a shield and moves from side to side to protect the nymphs.

How Do Stinkbugs Grow Up?

Stinkbugs, like all true bugs, change as they grow. Like all insects, they go through a process called metamorphosis (met uh MAWR fuh sihs). But stinkbugs don’t change as much as many other insects do. Most insects go through four stages of development, while stinkbugs go through three. That’s why a stinkbug’s metamorphosis is incomplete.

A nymph has a shape much like an adult. Nymphs are smaller than adults, though. And nymphs don’t have wings, as most adults do.

A nymph is born with a hard outer layer of skin that it soon outgrows. So the nymph molts, or sheds its skin. After the first molt, small padlike wings appear on the nymph’s body. With each new molt, the wings grow longer. After the fifth and last molt, the wings are fully developed. A stinkbug nymph becomes an adult after about a month.

How Do Stinkbugs Defend Themselves?

A stinkbug’s main weapon of defense is its odor. When in danger, the stinkbug releases a stinking liquid from its thorax. A bird or other predator often takes one whiff of the bug’s rotten smell and leaves the tiny creature alone.

Some stinkbugs also rely on their color for protection. Many blend in so well with their surroundings that they go unnoticed. Stinkbugs that are green, for example, are hard to see on green leaves and stems. Other stinkbugs have brown and gray patterns that help them blend in with tree bark.

What Does a Harlequin Bug Look Like?

The harlequin (HAHR luh kihn) bug is a kind of stinkbug. This stinkbug is about 3/8 of an inch (10 millimeters) long. The harlequin bug may be small, but its colors make it easy to see. This bug’s name means “many colors.” The bug is black with bright red, orange, or yellow markings all over its body. Scientists think that these dazzling colors warn predators to stay away from this stinky bug.

Harlequin bugs often “hang out” on the leaves of their favorite crop: cabbage. These bugs often gather in large bunches. When they do, they can quickly destroy a cabbage crop.

Harlequin bugs once lived only in Mexico. Today, they live all over North America.

Stinkbugs make up the order Hemiptera, family Pentatomidae. The harlequin cabbage bug is Murgantia histrionica.