Stink bugs, members of the insect family Pentatomidae, are common insects recognized by their shield-shaped bodies and the characteristic odor they release when disturbed. Found globally, with over 50 species in California alone and hundreds across North America, their size ranges from 0.5 to 0.75 inches in length. Their coloration varies, often blending with their environment. This diverse group plays multiple roles within ecosystems, influencing plant health and food webs.
Stink Bugs as Predators
Some stink bug species are beneficial predators, contributing to natural pest control. These predatory stink bugs feed on other insects, including agricultural pests, using specialized mouthparts to pierce prey and extract body fluids. This behavior helps regulate destructive insect populations.
For example, the spined soldier bug (Podisus maculiventris) preys on soft-bodied insects like caterpillars, beetle larvae, and Mexican bean weevils, which are significant crop pests. The two-spotted stink bug (Perillus bioculatus) targets Colorado potato beetle larvae and eggs. These predatory stink bugs can reduce the need for chemical pesticides, supporting a more balanced agricultural environment.
Stink Bugs as Herbivores
Many stink bug species are herbivores, feeding on a wide range of plants, including fruits, vegetables, and field crops. They use piercing-sucking mouthparts to extract plant sap, which can lead to various forms of plant damage. This feeding can lead to significant economic losses in agriculture, affecting crop yield and marketability.
The brown marmorated stink bug (Halyomorpha halys), an invasive species, exemplifies a herbivorous pest. It feeds on over 100 plant species, including apples, peaches, corn, and soybeans. Damage to fruits includes pitting, scarring, or a mealy texture, making them unmarketable. In corn, they cause shriveled grains, and in soybeans, their feeding can cause a “stay green” effect where plants remain green later into the season. Stink bug feeding can also create wounds, allowing entry for diseases.
Stink Bugs as a Food Source
Despite their defensive odor, stink bugs serve as a food source for various animals within the broader food web. Their presence contributes to the diets of numerous predators, supporting biodiversity. Different animals consume stink bugs at various life stages, from eggs to adults.
Birds and spiders consume stink bugs. Some parasitic wasps, such as the samurai wasp (Trissolcus japonicus), are egg parasitoids, laying their eggs inside stink bug eggs, preventing them from hatching. Other insects like assassin bugs and tachinid flies also prey on stink bugs. Amphibians and reptiles include stink bugs in their diet, integrating them into the ecosystem’s energy flow.