They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago.

Grasshoppers are plant-eaters, with a few species at times becoming serious pests of cereals, vegetables and pasture, especially when they swarm in the millions as locusts and destroy crops over wide areas.

[9][10] [6 superfamilies] Tridactyloidea Tetrigoidea Eumastacoidea Proscopioidea Pneumoroidea Pyrgomorphoidea Acridoidea In evolutionary terms, the split between the Caelifera and the Ensifera is no more recent than the Permo-Triassic boundary;[11] the earliest insects that are certainly Caeliferans are in the extinct families Locustopseidae and Locustavidae from the early Triassic, roughly 250 million years ago.

[12][13] Morphological classification is difficult because many taxa have converged towards a common habitat type; recent taxonomists have concentrated on the internal genitalia, especially those of the male.

[19] Those species that make easily heard noises usually do so by rubbing a row of pegs on the hind legs against the edges of the forewings (stridulation).

[20] Grasshoppers may be confused with crickets, but they differ in many aspects; these include the number of segments in their antennae and the structure of the ovipositor, as well as the location of the tympanal organ and the methods by which sound is produced.

On the side of the head are a pair of large compound eyes which give a broad field of vision and can detect movement, shape, colour and distance.

There are numerous fine hairs (setae) covering the whole body that act as mechanoreceptors (touch and wind sensors), and these are most dense on the antennae, the palps (part of the mouth), and on the cerci at the tip of the abdomen.

Other functions of the haemolymph include wound healing, heat transfer and the provision of hydrostatic pressure, but the circulatory system is not involved in gaseous exchange.

[33] Grasshoppers jump by extending their large back legs and pushing against the substrate (the ground, a twig, a blade of grass or whatever else they are standing on); the reaction force propels them into the air.

[38] Co-contraction can last for up to half a second, and during this period the extensor muscle shortens and stores elastic strain energy by distorting stiff cuticular structures in the leg.

The songs are a means of communication; the male stridulation seems to express reproductive maturity, the desire for social cohesion and individual well-being.

Social cohesion becomes necessary among grasshoppers because of their ability to jump or fly large distances, and the song can serve to limit dispersal and guide others to favourable habitat.

Some exceptions include the chameleon grasshopper (Kosciuscola tristis), where males may fight on top of ovipositing females; engaging in leg grappling, biting, kicking and mounting.

After mating, the female of most species digs a hole with her ovipositor and lays a batch of eggs in a pod in the ground near food plants, generally in the summer.

[46] Following this transformation, under suitable conditions dense nomadic bands of flightless nymphs known as "hoppers" can occur, producing pheromones which attract the insects to each other.

With several generations in a year, the locust population can build up from localised groups into vast accumulations of flying insects known as plagues, devouring all the vegetation they encounter.

The bacteria Serratia marcescens and Pseudomonas aeruginosa have both been implicated in causing disease in grasshoppers, as has the entomopathogenic fungus Beauveria bassiana.

[56] The fungal pathogen Entomophaga grylli is able to influence the behaviour of its grasshopper host, causing it to climb to the top of a plant and cling to the stem as it dies.

Dictyophorus productus (Pyrgomorphidae) is a "heavy, bloated, sluggish insect" that makes no attempt to hide; it has a bright red abdomen.

[61] Another species, the rainbow or painted grasshopper of Arizona, Dactylotum bicolor (Acridoidea), has been shown by experiment with a natural predator, the little striped whiptail lizard, to be aposematic.

The seemingly static scene is animated by a "grasshopper on the table that looks about ready to spring", according to the gallery curator Betsy Wieseman, with other invertebrates including a spider, an ant, and two caterpillars.

[69] During the Greek Archaic Era, the grasshopper was the symbol of the polis of Athens,[70] possibly because they were among the most common insects on the dry plains of Attica.

[72] Grasshoppers appearing in dreams have been interpreted as symbols of "Freedom, independence, spiritual enlightenment, inability to settle down or commit to decision".

Locusts are taken literally to mean devastation of crops in the case of farmers; figuratively as "wicked men and women" for non-farmers; and "Extravagance, misfortune, & ephemeral happiness" by "gypsies".

[79] It is recorded in the Bible that John the Baptist ate locusts and wild honey (Greek: ἀκρίδες καὶ μέλι ἄγριον, akrídes kaì méli ágrion) while living in the wilderness.

This means that although precipitation is needed to stimulate plant growth, prolonged periods of cloudy weather will slow nymphal development.

They are mentioned in both the Qur’an and the Bible and have also been held responsible for cholera epidemics, resulting from the corpses of locusts drowned in the Mediterranean Sea and decomposing on beaches.

[87] In February 2020, researchers from Washington University in St. Louis announced they had engineered "cyborg grasshoppers" capable of accurately detecting explosives.

The name is said to have originated when Major General Innis P. Swift saw a Piper making a rough landing and remarked that it looked like a grasshopper for its bouncing progress.