Grasshopper

A leg full of spring

A grasshopper can launch itself 20 times its body length in a single jump — equivalent to a person leaping the length of a basketball court. The mechanism uses elastic energy stored in a spring-like structure called the semi-lunar process in the knee joint. The leg muscles slowly compress this spring while bracing against a catch; releasing the catch fires the leg in milliseconds, far faster than the muscle alone could move.

The same biomechanical principle powers crossbows, mousetraps, and the recoil of ricoching pinball flippers — slow loading, fast release.

Locust transformation

Several species in the family Acrididae undergo a dramatic transformation under crowded conditions, becoming locusts — a behavioral, morphological, and even color phase change. When solitary grasshoppers experience repeated physical contact with other grasshoppers (the trigger is touch on the hind legs), levels of the neurotransmitter serotonin rise, and a cascade of changes follows:

• Body color shifts from green to yellow or black.
• Wings grow longer.
• Behavior becomes gregarious.
• Females lay more eggs.
• Offspring inherit the swarming phase.

A single locust swarm can contain billions of individuals and devastate crops across thousands of square kilometers. The 2020 East African locust outbreak was the worst in 70 years, threatening food security for millions.

How they sing

Most grasshopper “songs” are produced by stridulation — rubbing rough surfaces against each other. Hind legs have ridges that scrape across hardened forewings, producing a chirping or buzzing sound. Each species has a distinctive song used for territorial advertising and mate attraction.

Crickets stridulate in a slightly different way (rubbing wing on wing); both belong to the order Orthoptera. The ridge-and-scraper system is one of evolution’s recurring inventions.

A common food

People eat grasshoppers across many cultures:

• Mexico — chapulines, toasted with chili and lime, an Oaxacan staple.
• Uganda — nsenene, deep-fried and salted.
• Cambodia, Thailand — fried grasshoppers as snacks.
• Israel — Schistocerca gregaria (desert locust) is the only insect kosher under Jewish law.

Grasshoppers are about 60% protein by dry weight — much higher than beef — and produce a fraction of the greenhouse gas emissions per kilogram of protein. The case for insects as a sustainable food source has been made for decades.

Damage to crops

Even non-swarming grasshoppers cause significant agricultural damage in normal years. A single adult eats roughly half its body weight in vegetation per day. Hot dry summers correlate with population booms; rainfall reduces them. The economic threshold for control is typically 8–10 grasshoppers per square yard.