Grasshoppers belong to the insect order Orthoptera, which also includes crickets and katydids. They are not nocturnal; they are primarily diurnal, meaning their most active period occurs during daylight hours. This schedule is governed by external factors that dictate when they can effectively feed, move, and reproduce.
Defining the Grasshopper’s Activity Cycle
The grasshopper’s day is dominated by movement and foraging, a behavior pattern characteristic of diurnal species. During daylight hours, they dedicate significant time to herbivorous feeding, consuming grasses and other plant foliage. They are highly mobile, using their powerful hind legs for leaping to escape predators or move between food sources.
Adult grasshoppers also engage in courtship and mating rituals. Males produce species-specific sounds through stridulation—rubbing their hind legs against their wings—to attract females. Their ability to fly enhances their mobility, allowing them to cover greater distances for feeding and finding mates.
Environmental Factors Governing Activity
Grasshoppers are daytime-active because they are ectotherms, or cold-blooded animals. They lack internal mechanisms to generate sufficient heat, making them reliant on external sources like solar radiation and ambient temperature for energy. Without warmth, their muscles and metabolic processes cannot function effectively for sustained activity.
Activity is limited by low temperatures; most species require a minimum body temperature of around 11 to 12°C just to begin walking. As the sun rises, they engage in basking behavior, orienting their bodies to maximize sun exposure and rapidly elevate their internal temperature. Basking allows them to raise their body temperature by a substantial margin, often 7 to 20°C above the surrounding air temperature.
Their optimal performance window occurs when their internal temperature stabilizes between approximately 31 and 36°C, supporting activities like feeding and fast movement. If the environment becomes too hot, they adjust their behavior by climbing vegetation or moving into the shade. This allows them to regulate their body temperature, preventing overheating while maintaining the necessary warmth for functioning.
What Grasshoppers Do After Dark
As the sun sets and temperatures drop, grasshoppers transition into a state of inactivity or rest. Their body temperature rapidly declines, matching the ambient air temperature due to their ectothermic nature. This temperature drop drastically reduces their metabolic rate and motor function, making large-scale movement impractical.
To conserve energy and avoid ground-level predators, grasshoppers seek shelter by climbing onto dense vegetation or underneath leaves. While resting, they remain motionless and are much less responsive to external stimulation compared to daytime. This period of minimal movement is essential for survival, allowing them to wait for the morning warmth that will reactivate their bodies.