Many people confuse locusts and cicadas, often due to their large numbers and noticeable presence. However, these are distinct insects with significant differences in their biology, behavior, and ecological roles.
Understanding Locusts
Locusts are short-horned grasshoppers, classified under the order Orthoptera. They typically have slender bodies, large hind legs for jumping, and range from 1 to 2 inches in length. Their coloring can vary, often appearing green or brown.
Locusts are herbivores, primarily consuming grasses, leaves, and various crops. They are known for their ability to transform from a solitary phase to a gregarious, swarming phase. This shift is triggered by overcrowding and abundant vegetation.
Swarms can consist of billions of individuals, moving across vast areas and devastating agricultural lands. Historically, locust swarms have caused widespread famine and economic disaster in affected regions.
Understanding Cicadas
Cicadas are true bugs, classified under the order Hemiptera. They are characterized by stout bodies, broad heads, prominent widely-set eyes, and two pairs of clear, membranous wings. Cicadas typically measure between 0.8 to 2 inches in length.
They primarily feed on plant sap. Nymphs spend most of their lives underground, while adults consume sap from twigs and branches. Their most distinctive feature is the loud, often droning sound produced by males to attract mates.
Cicada life cycles can be annual or periodical, with large broods emerging synchronously every 13 or 17 years. Despite their loud presence, cicadas are generally harmless to humans and mature trees.
Key Differences That Set Them Apart
The fundamental distinctions between locusts and cicadas span their classification, physical traits, diet, sound production, and behavior. Locusts are Orthoptera (grasshoppers), while cicadas are Hemiptera (true bugs). Locusts possess chewing mouthparts, enabling them to consume entire plant matter. In contrast, cicadas have specialized piercing-sucking mouthparts designed for liquid sap extraction from the xylem of trees and woody shrubs.
Their diets also differ significantly: locusts are voracious herbivores that consume leaves, stems, and crops, posing a substantial threat to agriculture during swarms. Cicadas, however, feed exclusively on tree sap and are generally not considered agricultural pests, although heavy egg-laying can cause minor damage to young tree branches.
Sound production is another clear differentiator. Male locusts produce sounds by stridulation (rubbing their body parts together), creating chirping or buzzing noises. Cicadas generate their exceptionally loud and continuous calls using specialized tymbal organs located on their abdomens.
Behaviorally, locusts are known for their swarming, a dramatic transformation from a solitary to a gregarious phase triggered by environmental conditions and population density. This leads to mass migrations that can cover vast distances. Cicadas, particularly periodical ones, exhibit mass emergence after spending years underground; this is a synchronized life cycle event, not a density-driven swarm. While both appear in large numbers, the nature and impact of these aggregations differ greatly.