Grasshoppers are a common sight, and their seasonal appearance often prompts questions about when they become active. These insects, known for their powerful jumping legs and herbivorous diets, follow a distinct timeline throughout the year.
Typical Emergence Times
Grasshoppers typically emerge from their overwintering egg stage as nymphs from late spring to early summer. In regions like the Northern Plains, this period generally spans from early May to late July, though the exact timing can vary annually. “Emergence” in this context refers to the hatching of eggs and the appearance of these wingless, immature grasshoppers.
The timing of emergence shows regional variations, occurring earlier in warmer climates and later in cooler or higher-altitude areas. The hatching period for a single grasshopper species can extend for several weeks, typically ranging from two to six weeks.
Environmental Triggers for Emergence
The primary environmental cues that prompt grasshopper eggs to hatch are soil temperature and moisture levels. Consistent warmth in the soil is a key factor, with temperatures generally needing to be above 50 to 55°F (10 to 13°C) for embryonic development to resume and eggs to hatch. Warmer spring temperatures can accelerate the hatching process, leading to earlier emergence dates.
Moisture in the soil also plays a significant role; moist conditions can accelerate hatching, while overly dry soil may delay it. Sufficient soil moisture is also necessary for the eggs to survive the winter. The accumulation of “day-degrees,” a measure of heat units over time, determines the rate of embryonic development, requiring specific amounts of heat in both the fall and following spring for successful hatching.
Grasshopper Life Cycle and Active Periods
The life cycle of most grasshoppers involves three main stages: egg, nymph, and adult, a process known as incomplete metamorphosis. Female grasshoppers typically lay their eggs in the soil during late summer and fall, where they remain dormant through the autumn and winter months, often for about ten months. These eggs are protected in pods, usually buried an inch or two underground.
Upon hatching, grasshopper nymphs emerge, resembling smaller versions of adults but without fully developed wings. These nymphs grow by shedding their exoskeleton multiple times, typically undergoing five to six molts, a process called instars. The nymphal stage generally lasts between 30 to 50 days, or about five to six weeks, depending on the species and environmental conditions. After their final molt, they develop into winged adults.
Adult grasshoppers are then active, feeding and reproducing, typically living for two to three months through the summer and into the fall, until the onset of cold weather.