Distinctive Shield and Beak

• Shield bugs, like stink bugs, have a distinctive, triangular-shaped plate that is attached to their backs, covering their wings and lower body parts. This protective plate resembles a shield and is known scientifically as the "scutellum." Shield bugs also have a distinctive beak, known scientifically as the "rostrum," which is used to pierce food sources and suck out the juices contained within. Most shield bugs are herbivores, or plant eaters, but some prey on other insects and some consume both plants and insects.
  
  

Location

• Shield bugs are found primarily in fields, shrubs, bushes and—in farm areas—on plants and crops. In cooler climates, they will inhabit woodland areas. Plant-eating shield bugs are not harmful to humans, but they can damage produce. As a result, some shield bugs are considered pests by farmers and gardeners. Some crops that are especially favored by shield bugs are beans, cabbage, cotton, melon, squash and tomatoes.
  
  

Egg Laying

• Female shield bugs lay their eggs in late spring to early summer. In general, approximately 200 eggs are laid on plant leaves and stems in clusters of 20 to 30. Once these oval or barrel-shaped eggs hatch, the juvenile shield bugs, known as "nymphs," take about one month to reach adulthood. This process is usually completed by September each year.
  
  

Hibernation

• In November of each year, shield bugs begin the process of hibernation. Shield bugs preparing to hibernate in areas where there are trees or where there is abundant vegetation seek out patches of moss or tree trunks that contain bark openings. Certain other shield bugs seek an indoor shelter that offers a hiding place. In early spring, the shield bug emerges from hibernation and focuses on reproduction.
  
  

Predators

• Some shield bugs do prey on other insects. These predator shield bugs use their sharp rostrums to pierce the bodies of their victims and then suck out the victims' body fluids, causing death to the drained insects. Such predator shield bugs are generally considered allies by farmers because their targets are often insects that do even more damage to crops and farm vegetation.
  
  

Identification

• Although shield bugs resemble beetles, they do not possess mouth parts that allow for chewing, as beetles do. Shield bugs can range in length from 1/4 inch to 1 inch and may be dark or bright in color. Some, in fact, are multicolored or feature distinctive markings, such as spots or geometric shapes. They have two feelers, or antennae, attached to their heads, and—like stink bugs—can emit an unpleasant odor when agitated, threatened or crushed. The source of this odor is a liquid stored in the shield bug's glands. These glands are found in the insect's thorax, between both sets of legs.