Stink bugs, recognized by their distinctive shield-shaped bodies, are common insects, often prompting questions about their feeding habits. While some might assume a uniform diet across all species, the reality is more diverse, encompassing both plant-feeding and predatory behaviors.
The Primary Diet of Stink Bugs
The majority of stink bug species primarily feed on plants. These insects utilize specialized piercing-sucking mouthparts to extract juices from various parts of plants, including fruits, vegetables, seeds, and leaves. This feeding involves piercing plant tissue and injecting saliva, which can damage cells and lead to bruising or decay.
Newly hatched stink bugs, called nymphs, often begin feeding on weeds and grasses before moving to other plants as they mature. A prominent example is the brown marmorated stink bug (Halyomorpha halys), an invasive pest that causes significant damage to agricultural crops. This species can infest a wide variety of fruits and vegetables, causing substantial economic losses for farmers.
The Exception: Predatory Stink Bugs
While many stink bugs are plant feeders, a notable group consists of predatory species. These beneficial stink bugs play a role in natural pest control, preying on various soft-bodied insects. Their beaks are adapted to extract fluids from insect prey.
The spined soldier bug (Podisus maculiventris) is a well-known example of a predatory stink bug found in North America. This species feeds on over 100 types of pest insects, including caterpillars and beetle larvae. Both adult and nymph stages of predatory stink bugs actively hunt and consume their prey, contributing to the regulation of pest populations in agricultural and garden settings.
Identifying Stink Bugs by Their Feeding Habits
Distinguishing between plant-feeding and predatory stink bugs can be helpful for gardeners and homeowners. A primary visual cue lies in the morphology of their mouthparts, the beak. Predatory stink bugs typically possess a shorter, stouter beak, which is at least twice as thick as their antennae. This robust beak is suited for piercing the tough exoskeletons of their insect prey.
Conversely, herbivorous stink bugs have a more slender, often longer beak, which is roughly the same width as their antennae. These delicate mouthparts are designed for piercing plant tissues to access sap and juices. Observing the bug’s location and behavior can also provide clues; plant feeders are often found directly on damaged fruits or leaves, while predatory species might be seen near or actively consuming other insects.