Grasshoppers are insects belonging to the order Orthoptera and are primarily phytophagous, meaning they feed on plants. A significant portion of their diet is composed of grasses and other herbaceous vegetation. They function as primary consumers in grassland ecosystems, transferring energy from plants into the food web.
Grass as a Staple Food Source
Many grasshopper species are classified as graminivorous, indicating a preference specifically for grasses. They often select green grass leaves, which contain a high water content, typically ranging from 60% to 80%, providing both hydration and nutrients. Dense populations can consume a large volume of forage, causing defoliation of both native and cultivated grasses.
The tough nature of grass is due to its high content of structural carbohydrates, such as cellulose and hemicellulose. To process this material, grasshoppers have specialized digestive systems. Some species possess the enzyme cellulase, which softens plant cell walls, making the contents more accessible to other digestive enzymes. Furthermore, the grasshopper gut hosts symbiotic bacteria, such as Enterobacter, which aid in the decomposition and utilization of these plant fibers.
Dietary Diversity and Alternative Food Sources
While grass is a major food source, most grasshoppers are polyphagous, meaning they can consume many different types of plants. This dietary flexibility allows them to thrive across various environments and adapt to seasonal changes in vegetation. They consume broadleaf plants, known as forbs, which include common weeds, alongside a variety of agricultural crops.
These insects readily feed on cultivated plants like corn, wheat, alfalfa, and lettuce, making them an agricultural concern when population numbers rise significantly. Beyond plant matter, some grasshoppers display opportunistic omnivory, especially when preferred plant resources are scarce. This behavior includes consuming insect larvae, scavenging on dead insects, or feeding on decaying organic matter and animal droppings to supplement protein and nutrient intake. Dietary preferences can also shift between life stages; young nymphs may feed heavily on weeds, while late-stage nymphs and adults often seek out more succulent food plants.
Specialized Mouthparts for Chewing
Grasshoppers possess a generalized type of chewing mouthpart, known as mandibulate, which is well-suited for processing tough, fibrous material like grass blades. The primary organs for ingestion are the strong mandibles, a pair of robust jaws that operate laterally, moving side-to-side. These mandibles allow them to cut, tear, and grind food into manageable pieces.
The mandibles of grass-feeding species are specifically adapted for this task, with the left mandible often featuring a smooth, knife-like cutting edge. This smooth surface allows for a scissor-like action necessary to cleanly slice through the tough, narrow structure of grass leaves. Other mouthpart components, such as the labrum (upper lip) and the maxillae, work together to manipulate the food and guide it toward the grinding surfaces.