Caelifera

Distinguished from Ensifera (katydids, crickets, mole crickets) by antennae shorter than the body and insertion of tympanal organs on the first abdominal segment rather than the fore tibiae. Within Caelifera, Tetrigidae (ground-hoppers) are recognized by the pronotum extended backward over the abdomen; Tridactylidae (pygmy mole crickets) by fossorial forelegs and small size; Acrididae (typical grasshoppers) by the combination of short antennae, functional wings in most adults, and jumping hind legs. Subfamilies of Acrididae are distinguished by head orientation (slant-faced vs. spur-throated vs. band-winged), presence of abdominal spurs, and wing coloration.

Predominantly terrestrial, occupying grasslands, savannas, agricultural fields, deserts, alpine meadows, and tropical forests. Ground-hoppers (Tetrigidae) favor moist, shaded habitats with dense ground cover. Pygmy mole crickets (Tridactylidae) are semi-aquatic or associated with saturated soils. Most grasshoppers (Acrididae) are found in open, sunny habitats with herbaceous vegetation.

Worldwide distribution except Antarctica; predominantly tropical with highest diversity in Africa, South America, and Southeast Asia. Representative species occur in all continental temperate zones.

Most temperate species exhibit univoltine or bivoltine cycles with adults active from late spring through autumn. Tropical species may be active year-round. Diapause as eggs is common in temperate climates; some species overwinter as nymphs.

Almost exclusively herbivorous, feeding on grasses, forbs, sedges, and other vascular plants. Some species are generalist feeders while others exhibit narrow host plant specificity. A few species have been observed consuming detritus, dung, or dead insects, but this is not the primary feeding mode.

Hemimetabolous development: egg → nymph (4–6 instars) → adult. Eggs are deposited in pods within soil, plant stems, or other substrates, with embryonic development arrested in diapause over winter in temperate species. Nymphs resemble wingless adults and undergo successive molts, with wing pads developing progressively through instars. Adults are sexually mature after a pre-reproductive period of 1–2 weeks.

Primarily diurnal, with peak activity during warm, sunny conditions. Most species are solitary, though some exhibit density-dependent phase polyphenism leading to gregarious behavior and swarming (locusts). Males produce species-specific calling songs by stridulating hind legs against forewings or tegmina. Females respond to male songs and select mates. Oviposition involves digging with the ovipositor and depositing eggs in protective pods. Defensive behaviors include jumping, flying, thanatosis (playing dead), and chemical secretion (in some Pyrgomorphidae).

Major primary consumers in grassland and savanna ecosystems, transferring plant biomass to higher trophic levels. Serve as critical food resources for vertebrate predators (birds, reptiles, mammals) and invertebrate predators (spiders, robber flies, wasps). Nutrient cycling through fecal deposition and carcass decomposition. Some species function as ecosystem engineers through oviposition disturbance of soils. Population outbreaks can dramatically alter vegetation structure and composition.

Significant agricultural pests, particularly locusts (e.g., Schistocerca gregaria) and certain grasshopper species (e.g., Melanoplus sanguinipes, Locusta migratoria), which cause billions of dollars in crop and rangeland damage annually. Managed through chemical insecticides, biological control agents (Nosema locustae, Beauveria bassiana, Metarhizium), and cultural practices. Some species are consumed as food in many cultures. Used as model organisms in neurobiology, physiology, and ecological research. Mormon crickets (Anabrus simplex, actually a katydid but ecologically similar) and some grasshoppers are managed as rangeland pests in western North America.

• EnsiferaThe other orthopteran suborder, distinguished by long antennae (typically longer than body), tympanal organs on the fore tibiae, and slender, sword-like or needle-like ovipositor. Includes katydids, crickets, and true mole crickets (Gryllotalpidae).
• PhasmatodeaStick insects share elongate body form and herbivory but have cylindrical, non-enlarged hind legs, very long antennae, and lack the jumping specialization and tympanal organs of Caelifera.
• MantodeaPraying mantises share raptorial forelegs with some ground-dwelling grasshoppers but are predatory, have triangular heads with large eyes, and possess elongated prothorax not seen in Caelifera.

The term 'locust' is often misapplied taxonomically; it refers to a behavioral phase (gregarious, swarming) within certain grasshopper species rather than a distinct taxonomic group. Mormon crickets (Anabrus simplex) are frequently called crickets but belong to Ensifera (Tettigoniidae), not Caelifera. Pygmy mole crickets (Tridactylidae) are sometimes confused with true mole crickets (Gryllotalpidae in Ensifera), which are larger, have different burrowing adaptations, and are unrelated.

• orthoptera
• grasshopper
• locust
• pest
• herbivore
• jumping insect
• agriculture
• rangeland
• primary consumer
• hemimetabolous

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Grasshoppers of Colorado
• Grasshoppers of Wyoming and the West
• Grasshoppers of Colorado
• Grasshoppers of Wyoming and the West
• Grasshoppers of Colorado
• Grasshopper Links
• Annotated catalogue of Pakistani Acrididae (Orthoptera: Caelifera: Acridoidea)
• Checklist de Caelifera (Acridoidea e Eumastacoidea) do Estado do Rio de Janeiro (Orthoptera)
• First DNA barcodes and morphometric analysis of Singaporean Tetrigidae (Orthoptera, Caelifera) support color variations as intraspecific polymorphism through integrative taxonomy.