Grasshoppers hear with belly ears and jump at twenty g
Caelifera are among the oldest living chewing herbivores, dating to the early Triassic about two hundred fifty million years ago. Powerful hind legs launch them from danger; a large locust can clear a metre—some twenty body lengths—with peak acceleration near twenty g. Crowding can turn some species into swarming locusts.
They are hemimetabolous: eggs hatch as hoppers that moult five times toward adulthood. Hearing sits in tympanal organs on the first abdominal segment, not the head; compound eyes handle form and motion while ocelli track light. Short, stout antennae with few segments separate them from long-horned ensiferans. About two thousand four hundred genera and eleven thousand known species fill mostly tropical ranges, with Acridoidea alone near eight thousand. The name Caelifera means chisel-bearing, for the female ovipositor.
Escape and display shape daily life. Camouflage hides them; when spotted, many flash bright hindwings as they leap into short flights. Males often stridulate by scraping femoral pegs on forewing edges; some crepitate with flight clicks. Most are polyphagous plant-eaters favouring grasses and cereals; a few take animal tissue, and swarming bands can turn cannibal. Digestive tricks include midgut ceca for protein and, in some, cellulase that softens plant walls.
The Permo-Triassic split from Ensifera is at least that old; modern families such as Eumastacidae appear by the Cretaceous. Humans have faced famine from locust swarms since Biblical times, yet also eat grasshoppers in places like Mexico and Indonesia. Study of the group is acridology. An open haemolymph system and tracheal breathing move nutrients and air separately; setae and chordotonal organs feed a classic insect nervous system that makes each leap look simple even while the physics stay extreme.
Source: Grasshopper
