Stink bugs, sometimes called shield bugs, are in the scientific order Hemiptera and in the family Pentatomidae. There are 221 species of stink bugs in North America. Among the various species, the adult size ranges from 5 to 18 millimeters. While some stink bugs are considered beneficial insects because of the pests they consume, other stink bugs are considered pests because of the damage they do to crops. The most distinctive quality of stink bugs is the odor they emit, though they are not the only bugs to release such an odor in self-defense.Adult stink bugs are broad and have four wings. They are oval in shape and have a large scutellum, a plate that is triangular in shape, near the front of the top of their bodies. Most are green or brown in color, though there are species that are marked in bright oranges and yellows. Stink bugs also have a distinctive beak that is important for the way in which they consume food.
Most types of stink bugs eat plants, though a few are predators of smaller insects. The plant-eating stink bugs insert their beaks into plants and extract juices. Cabbage, green beans and other vegetable crops are among their favorite meals. Predatory stink bugs insert their beaks into caterpillars and other types of insects and drain fluids from their victims. Scientists and farmers are using some types of predatory stink bugs as pest control.
Stink bugs are found in copious amounts throughout the eastern United States, from the south into New England, and in lesser amounts, throughout much of the rest of North America. They are most often found in fields, yards and gardens, but rarely make their way indoors. They are active from spring through fall, and spend the winter underground or beneath leaf litter.
The female stink bug lays eggs in clutches of 20 to 30 barrel-shaped eggs. The eggs are deposited on the undersides of leaves. In many species, the mother bug guards her eggs until they hatch. Wingless nymphs emerge from the eggs. They go through four molts before reaching the adult stage of development. The adult female emerges from hibernation carrying eggs and seeking a suitable location in which to lay them.
The stink bug derives its name from the odor it emits when it is disturbed or frightened. The odor, which is emitted from the thoracic glands on the bug’s side, is a self-defense mechanism and is used to deter predators. The fluid that is omitted also tastes badly and may cause birds, spiders, assassin bugs and other predators to drop the bug if they are about to consume it.