Stink Bugs of Family Pentatomidae

What's more fun than a stink bug? The insects of the family Pentatomidae do, indeed, stink. Spend a little time in your backyard or garden, and you are sure to encounter a stink bug sucking on your plants or sitting in wait of a caterpillar.

About

The name Pentatomidae, the stink bug family, comes from the Greek "pente," meaning five and "tomos," meaning section. Some entomologists say this refers to the 5-segmented antennae, while others believe it refers to the stink bug's body, which appears to have five sides or parts. Either way, adult stink bugs are easy to recognize, with wide bodies shaped like shields. A long, triangular scutellum characterizes an insect in the family Pentatomidae. Take a close look at a stink bug, and you will see the piercing, sucking mouthparts.

Stink bug nymphs often resemble their adult counterparts but may lack the distinctive shield shape. Nymphs tend to stay close to the egg mass when they first emerge, but soon venture out in search of food. Look for masses of eggs on the undersides of leaves.

Classification

• Kingdom - Animalia
• Phylum - Arthropoda
• Class - Insecta
• Order - Hemiptera
• Family - Pentatomidae

Diet

To the gardener, stink bugs are a mixed blessing. As a group, stink bugs use their piercing, sucking mouthparts to feed on a variety of plants and insects. Most members of the family Pentatomidae suck sap from the fruiting parts of plants and can cause significant injury to the plants. Some damage foliage as well. However, predatory stink bugs overpower caterpillars or beetle larvae, keeping pest insects in check. A few stink bugs begin life as herbivores but become predators.

Life Cycle

Stink bugs, like all Hemipterans, undergo simple metamorphosis with three life stages: egg, nymph, and adult. The eggs are laid in groups, looking like neatly arranged rows of tiny barrels, on stems and the undersides of leaves. When nymphs emerge, they look similar to the adult stink bug but may appear rounder rather than shield-shaped. Nymphs go through five instars before becoming adults, usually in 4-5 weeks. The adult stink bug overwinters under boards, logs, or leaf litter. In some species, the nymphs may also overwinter.

Special Adaptations and Defenses

From the name stink bug, you can probably guess its most unique adaptation. Pentatomids expel a foul-smelling compound from special thoracic glands when threatened. In addition to deterring predators, this odor sends a chemical message to other stink bugs, alerting them to danger. These scent glands also play a role in attracting mates and even suppress attacks by harmful microorganisms.

Range and Distribution

Stink bugs live throughout the world, in fields, meadows, and yards. In North America, there are 250 species of stink bugs. Worldwide, entomologists describe over 4,700 species in nearly 900 genera.