Grasshoppers and aphids are common insects found in gardens and agricultural fields. Since both frequently coexist on the same plants, many wonder if the grasshopper acts as a natural control agent for the aphid. Understanding the distinct feeding biology of each insect provides a clear answer regarding this potential predator-prey relationship.
Primary Diet of Grasshoppers
Grasshoppers are members of the order Orthoptera and are overwhelmingly herbivorous, meaning their diet consists almost entirely of plant matter. Their feeding habits are classified as phytophagous, focusing on consuming foliage, stems, seeds, and flowers. These insects have a voracious appetite, preferring grasses and crops such as corn, alfalfa, and wheat.
While some species are considered omnivorous and may occasionally consume dead insects (carrion) for a protein boost, this is an opportunistic behavior, not a primary hunting strategy. The consumption of animal matter occurs mainly when plant resources are scarce or when they need additional nutrients. Grasshoppers do not actively seek out or hunt live aphids as a regular part of their diet.
A closer relative, the cricket, is distinctly omnivorous and will regularly consume aphids and other small insect larvae. This difference highlights that grasshoppers are biologically designed to process plant material. Therefore, the grasshopper should not be considered an effective or reliable predator for controlling aphid populations.
Grasshopper Feeding Mechanics
The physical structure of the grasshopper’s mouthparts dictates its diet and explains why it does not prey on aphids. Grasshoppers possess mandibulate mouthparts, which are a generalized type of chewing mechanism adapted for processing tough, fibrous plant material. This system is composed of several parts, including the prominent, hardened mandibles.
The powerful mandibles function like a pair of scissors, operating from side to side to slice and cut through leaves and stems. These structures also feature molar surfaces designed for the grinding and crushing of bulk food items. This robust anatomy is perfectly suited for consuming large pieces of vegetation, but it is not adapted for capturing or consuming small, soft-bodied prey like aphids.
In contrast, true aphid predators, such as assassin bugs, utilize specialized piercing-sucking mouthparts. These predators use a sharp, needle-like stylet to penetrate the aphid’s exoskeleton and withdraw its internal contents. The grasshopper’s chewing mouthparts lack this specialized piercing ability, rendering them incapable of efficiently feeding on aphids.
Natural Predators of Aphids
Aphids have a wide range of natural enemies that actively hunt and consume them in gardens and fields. These beneficial insects provide a form of biological control that helps keep aphid numbers in check. Lady beetles, often called ladybugs, are perhaps the most recognized of these predators, with both the adults and the larvae consuming large numbers of aphids.
Lacewing larvae, sometimes known as aphid lions, are also voracious predators that use specialized, curved jaws to seize and feed on aphids. Hoverfly larvae, which look like small, legless maggots, are equally effective, piercing the aphid and sucking out its internal fluids.
Parasitic wasps represent a different form of biological control. The female wasp lays a single egg inside a live aphid, and the resulting larva feeds internally, killing the host. This process results in an inflated, bronze-colored shell known as an aphid “mummy,” which is a clear sign of successful natural pest control.