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Grasshopper

Grasshoppers are herbivorous insects belonging to the suborder Caelifera within the order Orthoptera, most commonly in the family Acrididae. They are distinguished from related insects like crickets by their short antennae, robust bodies, and enlarged hind legs specialized for jumping, which can propel them distances up to 20 times their body length. Typically measuring 1 to 7 centimeters in length, grasshoppers possess chewing mouthparts for consuming vegetation and two pairs of wings: leathery forewings (tegmina) that cover the abdomen and broader hindwings used for flight. With over 10,000 distributed worldwide, grasshoppers are most abundant in grasslands, meadows, and agricultural fields, where they play dual ecological roles as consumers of plant matter and prey for , reptiles, and mammals. They undergo incomplete , consisting of three stages: eggs laid in pods during late summer or fall, nymphs that hatch in and pass through 5 to 6 instars while developing wing pads, and winged adults that emerge in 30 to 50 days and live until frost in temperate regions. Most produce one per year, with populations fluctuating based on conditions—warm, dry s often lead to outbreaks. Ecologically, grasshoppers contribute to nutrient cycling by breaking down vegetation and returning nutrients to the , while also influencing structure through selective herbivory. In high densities, however, certain like the migratory grasshopper (Melanoplus sanguinipes) form swarms akin to locusts, migrating up to 100 kilometers per day and causing significant defoliation of crops such as grains, corn, and rangeland grasses. These outbreaks, which can reach densities of 20 to 30 individuals per , pose major challenges to , prompting strategies that balance ecological benefits with economic needs.

Taxonomy and evolution

Phylogeny

Grasshoppers are defined as members of the suborder within the , a group that also encompasses the suborder Ensifera, which includes and katydids; the distinction between these suborders is based on differences in length, structure, and auditory organs, with Caelifera typically featuring shorter antennae and a more robust body form. The phylogeny of is well-supported as monophyletic through molecular analyses employing genetic markers such as 18S and 28S , as well as mitochondrial genes including oxidase subunits and complete mitochondrial genomes; seminal studies, including those by Flook and Rowell (1997) using 18S rRNA and Song et al. (2015) integrating multiple loci, consistently recover as a cohesive distinct from Ensifera. A comprehensive of highlights major superfamilies, including the dominant (short-horned grasshoppers), Tetrigoidea (pygmy grasshoppers), and others such as and Pneumoroidea, with forming the most species-rich lineage. Evolutionary divergence between and Ensifera is estimated at approximately 355 million years ago, in the period. encompasses approximately 12,400 described species worldwide, with the superfamily containing the majority of species.

Fossil record

The fossil record of grasshoppers (suborder , order ) is relatively sparse, largely due to the challenges in preserving the soft-bodied structures of these , which often results in gaps, particularly for early forms where only isolated wings or fragmentary remains are available. The earliest potential representatives of appear in the late Permian, with the genus Alekhosara from Upper Permian deposits in (~259–252 million years ago, Ma), suggested as a stem-group member based on wing venation patterns indicative of early caeliferan affinities. This predates the more definitive diversification of the group in the , highlighting a possible origin in the Permian but with limited unequivocal evidence owing to preservation biases. The period marks the radiation of unequivocal , with the oldest confirmed fossils from the (~240 Ma) in , including Mesacridites in the extinct family Locustavidae, characterized by orthopteran wing venation and transferred from earlier protorthopteran classifications. Families such as Locustopsidae also emerge around this time (~250 Ma), with specimens showing early adaptations like stridulatory structures on the tegmina, suggesting the onset of acoustic communication in the lineage. These fossils indicate a rapid diversification following the Permian-Triassic extinction, with evidence of wing development transitioning from broader, more primitive forms to the narrower tegmina typical of later grasshoppers. In the era, deposits provide key insights into evolutionary transitions, such as the first described grasshopper from , Archiplectrum sinense (Locustopsidae), from ~165 Ma sediments, featuring enlarged hind femora that imply advanced jumping mechanisms similar to modern forms. amber and shale inclusions further document diverse caeliferans, including eumastacoids with preserved body structures revealing dietary and locomotor adaptations. By the , Eocene amber from the (~44 Ma) yields modern-like pygmy grasshoppers (), such as Danatettix hoffeinsorum, with detailed preservation of antennae, legs, and coloration, indicating stabilization of morphological traits post-Mesozoic. Overall, these fossils underscore gradual refinements in wing folding and hind-limb for enhanced locomotion, though the record remains incomplete for soft tissues like muscles.

Diversity and distribution

Grasshoppers (suborder ) comprise approximately 12,400 described worldwide, with recent surveys indicating ongoing discoveries that suggest this number continues to grow. The greatest occurs in tropical regions, where diverse open habitats support a majority of the global diversity, particularly in and , which together host over half of all known due to their extensive , , and forest-edge ecosystems. These play key ecological roles as primary herbivores, influencing structure and serving as prey for predators in and food webs across these biomes. The family dominates grasshopper diversity, encompassing more than 6,700 species that are widespread in temperate and tropical grasslands. , known for their often colorful and aposematic forms, includes about 487 species, primarily in tropical and subtropical areas of , , and . , or pygmy grasshoppers, features around 1,660 species adapted as ground-dwellers in moist, vegetated habitats near water bodies worldwide. Grasshoppers exhibit a , inhabiting every continent except and thriving in open habitats from arid deserts to montane meadows, though they are sparse in polar and extreme cold regions. High levels of characterize hotspots such as , where numerous species are restricted to the island's unique grassy biomes, and , with over 1,000 species of which more than 90% are endemic. They occupy a broad range of elevations and habitats, from in coastal grasslands to over 5,000 meters in the Himalayan highlands, where species adapt to alpine meadows and shrublands. Estimates suggest that up to several thousand additional undescribed exist, particularly in tropical wet forests and understudied regions, based on recent surveys revealing cryptic in these areas. This hidden richness underscores the importance of continued taxonomic efforts to fully document their global and ecological contributions.

Description

External morphology

Grasshoppers exhibit a distinct external characterized by a segmented body covered in a chitinous that provides protection and support. The body is divided into three primary regions: the head, , and , with the further subdivided into , mesothorax, and metathorax. The consists of hardened sclerites separated by flexible membranes, allowing for movement while maintaining structural integrity. The head forms a robust, capsule-like structure equipped with sensory and feeding appendages. It features two large compound eyes positioned laterally for wide-field vision, three simple ocelli arranged in a triangle on the vertex for light detection, and antennae that are typically filiform (thread-like) but can be ensiform (sword-shaped) or clavate (clubbed) in some , serving as chemosensory organs. Mouthparts are mandibulate, adapted for chewing vegetation, and include a , paired mandibles, maxillae with palps, and a labium; these are directed downward from the head's ventral surface. Additional head features include the frontal costa (a vertical ridge on the frons) and (cheek regions below the eyes), which vary in prominence across . The is a stout, box-like region that supports and flight structures. The is the largest , featuring a saddle-shaped pronotum with a carina () and lateral lobes divided by sulci (grooves), which the underlying tissues. It bears the first pair of legs, while the mesothorax and metathorax support the second and third pairs, respectively, along with the wings. The legs are segmented into coxa, , , , tarsus, and pretarsus (claws); the forelegs and middle legs are adapted for walking, but the hind legs are markedly enlarged for , with a robust, elongated and a slender armed with two rows of spines and paired calcars at the apex. Wings consist of leathery forewings, known as tegmina, which are narrow and protective, overlaying the broader, fan-like, membranous hindwings folded beneath them when at rest; wing length varies from long (macropterous) to short (brachypterous) depending on the and . The comprises 11 s, with the first often fused to the metathorax, and is more flexible than the anterior regions due to ring-like terga and sterna connected by intersegmental membranes. It houses the tympanum (hearing organ) on the sides of the first and terminates in cerci (sensory appendages) on the ninth . In females, the ends in a prominent composed of three pairs of valves (, ventral, and inner) used for depositing eggs into . Males lack the and instead possess a subgenital plate, epiproct, and sometimes (forked projections) associated with genitalia. Sexual dimorphism is evident in size and abdominal structures, with females generally larger than males to accommodate egg production. Males are typically smaller and feature specialized sound-producing organs on the and wings, such as file-and-scraper mechanisms on the tegmina and hind femora.

Coloration and camouflage

Grasshoppers exhibit a variety of pigmentation types that contribute to their overall coloration, including and , alongside more common green-brown polymorphisms driven by and ommochrome pigments. results in darker body forms due to elevated deposition in the , which can enhance in shaded or rocky habitats or aid by absorbing heat. , characterized by excessive red pigmentation from reduced , appears rarely and results in pink individuals that disrupt typical , potentially increasing visibility to predators. In certain species, structural colors arise through , where nanoscale cuticular structures interfere with light to produce shifting hues, as seen in the grasshopper Kosciuscola tristis, which turns from black to turquoise when body temperature exceeds 25°C. This structural mechanism supplements pigment-based colors, providing dynamic visual effects that may deter predators or signal during interactions. Cryptic coloration predominates in most grasshopper species, with or brown hues matching surrounding to evade visual predators like birds and . Polymorphic forms enhance this ; for instance, the grasshopper (Chorthippus parallelus) features genetically determined uniform , lateral green, and uniform brown morphs, where individuals preferentially select matching substrates—green morphs favoring lush and brown morphs grass—for improved effectiveness. Similarly, in the desert locust (Schistocerca gregaria), nymphs exhibit with or beige cryptic forms under low population densities, transitioning to more conspicuous black-patterned phases at high densities, though the phase prioritizes blending with foliage. Conversely, warning coloration appears in toxic species of the family , known as gaudy grasshoppers, which display bright aposematic patterns like red, yellow, and black to advertise chemical defenses sequestered from host plants. These vivid combinations, such as the red-black markings in some desert-adapted pyrgomorphs, signal unpalatability to potential predators, reducing attack rates. Seasonal and ontogenetic changes in coloration further refine , with nymphs typically paler and more uniformly to match tender vegetation, while adults darken through deposition, becoming browner to suit mature or dry habitats. In species like Sphingonotus grasshoppers, adults exhibit reversible , adjusting hue and darkening without molting in response to substrate color and temperature, driven by visual cues and environmental factors like humidity. Hormonal regulation, including neuropeptides such as corazonin in locusts, controls pattern development during instars, overriding initial maternal influences from crowding. The evolutionary role of these color strategies centers on predator-driven selection pressures favoring , as evidenced in the desert clicker grasshopper (Ligurotettix coquilletti), where banded and uniform frequencies align with heterogeneity, maintained by balancing selection through negative frequency-dependent predation. This polymorphism, genetically linked to large indels, promotes local and persistence across varied environments, highlighting as a key survival trait under visual hunting pressures.

Physiology

Diet and digestion

Grasshoppers are primarily herbivorous insects with a polyphagous , consuming a wide range of materials that predominantly include grasses but extend opportunistically to leaves, flowers, forbs, and depending on availability. This dietary flexibility allows them to exploit diverse vegetation in their habitats, with studies showing that grasses can comprise over 90% of their intake in environments, supplemented by smaller proportions of other types. While strictly herbivorous under normal conditions, some species exhibit limited omnivory, such as scavenging dead , particularly during periods of plant scarcity or environmental stress. The mouthparts of grasshoppers are specialized for processing tough tissues, featuring robust mandibles that grind into smaller particles and maxillae that assist in manipulation and handling. secreted from glands near the mouth contains enzymes, including a minor amount of , which begins the breakdown of starches into simpler sugars even before mechanical grinding. This adaptation enhances the initial stages of , preparing material for further processing in the gut. The digestive tract is divided into three main regions: the , , and . The includes the , a for temporary , and a armed with chitinous teeth-like plates that further pulverize ingested material. primarily occurs in the , where glandular cells secrete a suite of enzymes such as proteases and lipases to hydrolyze proteins, fats, and carbohydrates. The facilitates the of water and salts from the residual material, concentrating waste into fecal pellets before expulsion through the . Nutrient extraction from fibrous plant matter relies heavily on symbiotic bacteria residing in the gut, particularly in the and , which produce enzymes capable of degrading and that grasshoppers themselves cannot efficiently break down. These microbes enable the of up to approximately 50% of in some species, converting recalcitrant plant polymers into usable nutrients like glucose and . Grasshoppers preferentially select nitrogen-rich plants, as higher foliar nitrogen content correlates with improved growth, , and reproductive output in these herbivores. By consuming and excreting nutrient-concentrated feces, they accelerate nutrient cycling in ecosystems, enhancing nitrogen availability and influencing dynamics in grasslands.

Sensory organs

Grasshoppers possess compound eyes consisting of approximately 4,000 per eye, enabling a wide for detecting motion and shapes in their environment. These multifaceted structures provide mosaic vision, with each functioning as an independent photoreceptor unit that contributes to overall . Color vision in grasshoppers is mediated by spectral filters in the , allowing discrimination primarily in the green-yellow spectrum despite possessing a single visual pigment type, which limits compared to vertebrates. Additionally, three ocelli located on the serve as simple photoreceptors that detect light intensity and changes in illumination, aiding in orientation and basic photoperiod responses without forming detailed images. Hearing in grasshoppers is facilitated by tympanal organs located on the lateral sides of the first abdominal , consisting of a thin stretched over an air-filled chamber connected to sensory neurons. These organs exhibit peak sensitivity to frequencies between 5 and 50 kHz, encompassing the range of conspecific calling songs for attraction and alarm signals from predators, with thresholds as low as 30-40 SPL in some species. The tympanal nerves transmit auditory signals to the , allowing rapid behavioral responses such as escape jumps or phonotactic orientation toward potential mates. Olfaction and gustation are mediated by chemoreceptors distributed across the antennae and parts. The antennae bear numerous olfactory sensilla, including coeloconic and basiconic types housing neurons sensitive to volatile plant odors and pheromones, with sensilla counts varying by rearing conditions and sex—males often possessing more for enhanced detection. These receptors enable the detection of sex pheromones released by conspecifics during , facilitating species-specific attraction and aggregation. Gustatory sensilla on the maxillary and labial palps, which are segmented appendages near the , detect contact chemicals in food sources, assessing through receptors responsive to sugars, deterrents, and nutrients before ingestion. Mechanoreception involves hair-like sensilla distributed across the body surface, particularly on the cerci, legs, and antennae, which detect air currents, , and subtle vibrations through deflection of their cuticular shafts. These trichoid sensilla provide cues for flight stabilization and . Complementing this, the subgenual organ, a chordotonal sensillum complex located in the proximal of each leg, is highly sensitive to substrate-borne vibrations transmitted through the ground or plant stems, with detection thresholds below 1 displacement, aiding in predator avoidance and communication via vibratory signals. Sensory integration occurs primarily through the , comprising a () and subesophageal ganglion connected to a ventral nerve cord of segmental running along the body. This cord processes multimodal inputs from peripheral sensors, with in the thoracic and abdominal ganglia coordinating sensory information for reflexive behaviors, such as integrating visual with mechanosensory wind cues during locomotion. The decentralized structure allows local reflexes while relaying critical signals to the for higher-order decisions.

Circulation and respiration

Grasshoppers possess an open circulatory system characterized by a heart that pumps through the , the , without serving an oxygen transport function. The heart, located along the midline of the thorax and , consists of a tubular structure with ostia that allow to enter during ; contraction propels it anteriorly via the and posteriorly through accessory channels. Unlike closed systems, this open arrangement bathes organs directly in , facilitating nutrient distribution and waste removal. Accessory pulsatile organs supplement the dorsal heart by directing to extremities such as the legs and head; in grasshoppers, these organs are situated at the bases of the antennae, wings, and limbs, generating localized flows up to several millimeters per second to support function. Hemolymph in grasshoppers comprises approximately 90% water, along with inorganic ions like sodium, calcium, and , carbohydrates such as for , , , proteins, and nitrogenous wastes including . It also contains hemocytes, mobile immune cells that mediate clotting by forming aggregates at wound sites and contribute to defense through and encapsulation. The relies on a tracheal network originating from 10 pairs of spiracles—two thoracic and eight abdominal—that open to the exterior and branch into progressively finer tracheae and tracheoles for direct gas delivery to tissues. Unlike lungs, this system enables oxygen diffusion across thin tracheole walls without involvement, while exits via the same pathways. Active ventilation occurs through abdominal contractions that pump air, generating pressures up to 7 kPa and tidal volumes around 40 µl at rest, increasing rates 2- to 5-fold during heightened activity. Gas exchange primarily depends on within tracheoles, providing efficient oxygen supply to metabolically active tissues but constraining body size in larger grasshopper species due to diffusion limitations over greater distances. Circulatory and respiratory demands escalate during intense activities like jumping or swarming in locust-phase grasshoppers, where abdominal pumping frequency rises dramatically post-hop to restore tracheal oxygen levels, and flow accelerates to meet metabolic needs of flight muscles and appendages.

Locomotion

Grasshoppers primarily employ three modes of : jumping, walking, and flight, each adapted to their and life stage. Jumping serves as the dominant escape mechanism, powered by a catapult-like in the hind legs. The extensor tibiae muscle contracts slowly to flex the against the , storing in the semi-lunar processes—crescent-shaped cuticular structures at the distal end of the . This stored energy is released rapidly during extension, propelling the grasshopper forward in a ballistic . Capable jumps can cover distances up to 20 times the body length, enabling rapid evasion of predators. Walking occurs at lower speeds and involves an alternating tripod gait, where three legs (one foreleg, one midleg, and the contralateral hindleg) contact the ground simultaneously, providing stability. This pattern is coordinated by in the thoracic ganglia, with the hind legs stepping at approximately half the frequency of the forelegs to maintain balance. Energy efficiency in walking is enhanced by in the leg joints, which recaptures during stance phases and reduces the metabolic cost of . Flight in adult grasshoppers is powered by synchronous flight muscles, which contract once per neural impulse to drive hindwing flapping at frequencies of 15-20 Hz. These muscles deform the indirectly, elevating and depressing the wings for sustained forward propulsion or . Nymphs lack functional wings and rely solely on and walking until the final instars, when wing pads develop. Locomotor adaptations include muscle remodeling during molting, where histolysis breaks down and recycles existing muscle fibers to accommodate body growth in the . Sexual dimorphism affects flight capability, with females often larger and exhibiting reduced endurance due to higher body mass and energy allocation to . Jumping and flight rely on anaerobic bursts for initial power, leading to rapid fatigue after repeated efforts as lactate accumulates in the muscles. Endurance improves with aerobic metabolism after about two minutes, but prolonged activity still limits sustained locomotion.

Reproduction and development

Mating and stridulation

Grasshoppers primarily use acoustic signals produced through to facilitate , with males rubbing a row of pegs on the inner surface of their hind femora against a prominent on the forewings to generate species-specific sounds. These stridulatory signals typically range in frequency from 2 to 40 kHz, varying by and serving to attract receptive females over distances. In some gomphocerine , stridulation involves complex, bidirectional sequences of hindleg movements coordinated by metathoracic rhythm generators. Courtship in grasshoppers often combines acoustic signals with visual displays and, in certain species, pheromones to elicit female receptivity. Males perform stereotyped postures, such as antennal waving or hindleg elevation, alongside to court females, with quality—in terms of rhythm, duration, and intensity—influencing female . For instance, females in species like Chorthippus parallelus prefer males producing longer, more vigorous songs, which signal higher . Pheromones may supplement these cues in some acridids, enhancing close-range during . The process culminates in the transfer of a , a proteinaceous capsule containing , from the male to the female's via the . Copulation durations vary widely among , typically lasting from 30 minutes to 2 hours, during which the male remains attached to guard against rival suitors and ensure transfer. occurs in many grasshopper , with females multiple times to gain genetic benefits, such as increased viability, though this can impose costs on male paternity. Species-specific acoustic signals promote by preventing hybridization, as females respond preferentially to conspecific songs differing in temporal patterns or frequency dialects. In closely related sympatric species like Chorthippus biguttulus and C. mollis, divergent stridulatory rhythms and leg movement sequences ensure mate recognition, reducing interspecific matings. Reproductive behaviors in grasshoppers are regulated by (JH) secreted from the corpora allata, which stimulates gonadal maturation and enhances sexual readiness in adults. Elevated JH titers, often triggered by environmental cues like long-duration flight, promote vitellogenin synthesis and production, coordinating the onset of mating activity.

Life cycle

Grasshoppers undergo incomplete , known as hemimetaboly, characterized by three primary life stages: , , and . Unlike complete , there is no pupal stage; instead, resemble smaller versions of and develop gradually through a series of 5 to 6 instars, each separated by molting. In temperate regions, most have a univoltine spanning one year, with nymphal development lasting 30 to 60 days during summer under favorable conditions, influenced by environmental factors such as and availability. The stage begins when females deposit 10 to 120 (varying by ) into pods, forming a frothy plug to protect them from and predators. These pods are buried 1 to 10 cm deep in the , often in loose or bare areas. In temperate , enter —a state of developmental arrest—allowing them to overwinter and hatch in after about 6 to 9 months of , synchronized with favorable conditions. occurs when temperatures rise above 10–15°C, with nymphs emerging through a slit in the pod. Nymphal development involves progressive growth over 5 to 6 instars, lasting 30 to 60 days depending on species and conditions, during which the exoskeleton is shed via ecdysis to accommodate growth with each molt. Wing pads appear as external buds in early instars and elongate gradually, becoming functional only after the final molt; genitalia also develop incrementally, remaining immature until adulthood. Ecdysis is hormonally regulated by ecdysteroids, which peak to trigger apolysis (detachment from the old cuticle) and cuticle formation, ensuring synchronized metamorphic changes. Upon reaching the adult stage after the final molt, grasshoppers achieve within days, with typically ranging from 30 to 50 days in the field, though laboratory conditions can extend this to 50–60 days. peaks shortly after the final molt, as females allocate resources to production, often laying multiple pods over their lifespan before . Temperature profoundly influences the , accelerating development rates; optimal occurs around 30°C, where nymphal instars shorten and overall cycle time decreases, while extremes below 15°C or above 35°C can delay or halt progression. interacts with to affect egg viability and hatching success, with warmer, moderately moist conditions promoting faster embryonic development in non-diapausing eggs.

Behavior

Foraging behavior

Grasshoppers exhibit density-dependent strategies that shift between solitary and gregarious s, particularly in species prone to formation. In the solitarious , individuals actively avoid conspecifics through repulsive interactions, independently to minimize competition and reduce detection by predators. This behavior predominates at low population densities below a critical , approximately 0.1 individuals per square meter, allowing for dispersed resource exploitation in sparse environments. Conversely, high densities trigger a transition to the gregarious , where attraction to others promotes group formation and coordinated , enhancing efficiency in resource-rich but crowded areas. Foraging decisions in grasshoppers rely on sensory cues and learned associations to select suitable food s. Visual stimuli, such as color and light intensity, enable associative learning, where nymphs of species like Melanoplus sanguinipes link these cues to rewarding food after a single exposure, improving search efficiency by avoiding unsuitable patches. In locusts like Locusta migratoria, individuals pair visual cues with macronutrient content through trial-and-error, preferentially approaching colors associated with deficient proteins or carbohydrates during nutrient-specific deprivation. Tactile exploration further aids in assessing and during initial contact. Within groups, foraging dynamics involve that influences movement and resource use. In swarms, locusts employ strategies akin to central-place , returning to aggregated sites while depleting local patches, which heightens intraspecific and prompts to new areas. For specialist grasshoppers such as Hesperotettix viridis, reduced plant quality from prior feeding accelerates departure, equalizing damage across a landscape despite variable initial conditions. availability modulates group stability, with patchy resources fostering tighter aggregations and lower dispersal rates compared to uniform distributions. Daily patterns in grasshoppers are primarily diurnal, with activity peaking after morning basking to elevate body , though some desert incorporate crepuscular elements by shifting to open ground at dawn. Predation drives vigilance behaviors, where individuals under threat reduce time and increase scanning, balancing energy intake against survival in risky habitats. Adaptations for sustained foraging include nutritional balancing and preparatory loading for extended activity. Grasshoppers regulate protein-to- intake ratios, with migratory species like Chortoicetes terminifera maintaining a consistent ~1:2 ratio across variable communities to optimize growth and reproduction. Non-migratory forms adjust targets post-ingestion to compensate for imbalances, such as shifting from 1:1 to 0.58:1 in protein-limited sites. For , locusts engage in gut loading by elevating consumption up to 30% during flight preparation, enhancing reserves and endurance without altering overall protein needs.

Swarming and locust phases

Locusts exhibit a remarkable form of known as , allowing them to shift between a solitarious and a gregarious in response to environmental cues, primarily . In the solitarious , individuals are shy and cryptic, actively avoiding conspecifics and displaying subdued behaviors that aid in within sparse populations. Crowding triggers the transition to the gregarious , where locusts become bold, highly active, and attracted to one another, leading to aggregation and eventual swarm formation. This density-dependent shift is mediated by physical contact and visual stimuli from nearby individuals, altering behavioral, physiological, and morphological traits over hours to weeks. Among the approximately 20 locust species capable of swarming, the (Schistocerca gregaria) and the (Locusta migratoria) are the most notorious due to their extensive ranges and devastating outbreaks. The inhabits arid regions across , the , and parts of , while the spans grasslands in , , and . These species alternate between phases opportunistically, with the gregarious form emerging during favorable breeding conditions that lead to high densities. Gregarious locusts form massive swarms comprising billions of individuals, often covering areas from less than one square kilometer to hundreds of square kilometers. These swarms travel at flight speeds of 10-20 km/h, typically aligned with , enabling daily displacements of 100-200 km or more. Over multiple generations, swarms can migrate vast distances, up to 5,000 km, as demonstrated by trans-Atlantic crossings from to the . The involves profound physiological changes, including darkened coloration in nymphs—gregarious hoppers display black patterns on a background, contrasting with the green hues of solitarious ones—and morphological adaptations such as larger wings and broader body structures in adults to support sustained flight. These shifts are biochemically driven, with serotonin playing a key role in modulating neural pathways that promote aggregation and hyperactivity; elevated serotonin levels in crowded conditions facilitate the behavioral reversal from avoidance to attraction. A stark example of swarm impacts occurred during the 2020 East Africa outbreak of desert locusts, where unprecedented swarms devastated crops and pastures across , , , and neighboring countries, exacerbating food insecurity for approximately 20 million people amid concurrent challenges like and conflict. This event, the worst in decades, highlighted the rapid escalation from isolated bands to plague-scale invasions, underscoring the ecological and humanitarian consequences of phase polyphenism. More recently, in 2025, swarms of desert locusts reemerged in , particularly and , following favorable breeding conditions, demonstrating the persistent threat of density-triggered gregarious behavior.

Ecology

Habitats

Grasshoppers (: and related families) primarily inhabit open, herbaceous environments such as s, meadows, and savannas, where abundant vegetation supports their herbivorous diet and provides camouflage. These habitats span vast rangelands, including shortgrass prairies, mixed-grass steppes, and tallgrass meadows, often characterized by moderate to high plant productivity and seasonal precipitation. Secondary habitats include arid deserts, where species adapt to sparse vegetation, as well as forested edges and wetlands, though these are less common due to denser cover or water saturation limiting mobility. In the , grasshoppers exhibit high diversity in tropical and subtropical s, adapted to varied herbaceous layers. Similarly, in the , they thrive in Eurasian steppes and temperate meadows, favoring dry, open expanses that mirror ancestral associations. Microhabitat selection among grasshoppers involves vertical , with many partitioning space between ground-level and upper layers to optimize and . Ground-dwelling forms, such as certain Acridinae, prefer in drier microhabitats for burrowing and egg-laying, while others climb shrubs or grasses for access to taller foliage. and humidity niches typically range from 15–35°C and moderate relative humidity (40–70%), influencing activity peaks during warmer daylight hours and avoidance of extremes through behavioral adjustments like basking or shade-seeking. In arid zones, like the lubber grasshopper (Romalea microptera) exhibit burrowing adaptations, digging into sandy to escape and heat during the day. Tropical arboreal , conversely, perch on foliage in humid understories, leveraging vertical for predator evasion and access. Habitat fragmentation, often from , disrupts grasshopper populations by isolating patches and reducing , leading to decreased in remnant . Studies in Mediterranean landscapes show that fragmented semi-natural habitats limit dispersal, with dropping significantly across barriers wider than 1 km, exacerbating local extinctions in small patches. This effect is pronounced in grassland realms like the Palearctic, where via corridors sustains broader population viability.

Predators, parasites, and pathogens

Grasshoppers face predation from a diverse array of animals across various ecosystems. Birds, particularly species like kestrels (Falco sparverius), are significant predators, consuming grasshoppers as a primary component of their on rangelands, with studies showing they can regulate populations under favorable conditions. Reptiles such as (e.g., Eremias argus) actively hunt grasshoppers, impacting and abundance in grasslands. Invertebrate predators include spiders, like and , which ambush grasshoppers in vegetation, and praying mantids (Mantis religiosa), which use camouflage and rapid strikes to capture them. Opportunistic mammals, including ground squirrels, mice, and , also prey on grasshoppers, especially during outbreaks when availability is high. Parasitic organisms exploit grasshoppers through internal and external life cycles, often leading to host debilitation or death. Nematodes of the Mermis (e.g., Mermis nigrescens) infect nymphs via of eggs, developing internally for 4-10 weeks before emerging and killing the host. Mites from families like and Podapolipidae act as ectoparasites, attaching to adults and feeding on , which can reduce mobility and survival rates. Hairworms (: Gordiacea) are incidental endoparasites whose larvae manipulate infected grasshoppers to seek water bodies for emergence, often resulting in drowning of the host. Pathogenic microorganisms cause disease in grasshoppers, with fungi being prominent natural regulators. Beauveria bassiana infects through cuticle penetration, producing white mycelia and toxins that disrupt host physiology, leading to death within days under humid conditions. Similarly, Metarhizium acridum targets species, forming green mycelia and exhibiting high virulence in field settings. Viruses such as iridoviruses (e.g., those causing "dark cheeks" disease) spread via ingestion of infected material, killing hosts in 5-7 days and affecting swarming populations. Bacterial pathogens can infect grasshoppers but are less common and show limited efficacy in natural environments compared to fungi. Infection dynamics of these antagonists are often density-dependent, with epizootics intensifying in grasshopper swarms where close proximity facilitates or . High enhances fungal outbreaks, while immune responses, such as encapsulation of protozoan parasites or behavioral fever to elevate body temperature against mycoses, can mitigate infections. This reflects a co-evolutionary , where grasshoppers' thermoregulatory behaviors and immune adaptations evolve in response to , promoting ongoing selection for mechanisms.

Anti-predator defenses

Grasshoppers employ a diverse array of anti-predator defenses, encompassing morphological, behavioral, and chemical strategies that enhance survival against predators such as , , and wasps. These mechanisms often function in concert, allowing grasshoppers to detect threats early and respond effectively, with variations across and life stages. Morphologically, many grasshoppers, particularly band-winged like those in the genus Opeia, utilize startle displays involving the sudden flashing of brightly colored hindwings during . This deimatic behavior startles visual predators, providing a brief window for the grasshopper to flee, with the benefit increasing when the display occurs at greater distances from the approaching threat. Another key adaptation is , where grasshoppers voluntarily detach a hind leg at a fracture plane when grasped by a predator, such as a or wasp, allowing at the cost of reduced mobility. This defense is common in acridid and can impair future jumping performance, though regrowth occurs during molting. Behaviorally, grasshoppers exhibit thigmotaxis by seeking physical contact with vegetation or substrates to hide from predators, reducing visibility and facilitating in dense foliage. Thanatosis, or feigning death, is employed by some species, such as certain acridids, to appear uninteresting to predators like frogs or ; however, this strategy is less effective against persistent hunters and is debated as primarily a mating-related in some contexts. Rapid jumps represent a primary locomotor , with grasshoppers under predation modifying —such as increasing takeoff angles and hindleg extension speed—to achieve greater jump distances and heights, enhancing evasion from sit-and-wait predators like spiders. Chemically, certain grasshoppers produce defensive secretions from metathoracic glands, particularly in the family Romaleidae, such as the lubber grasshopper Romalea guttata, which emits quinones and phenolics that irritate predators' mouthparts and eyes. These autogenous compounds, synthesized independently of diet, render the insects unpalatable or toxic, deterring and predators; for instance, no birds or consumed lubber grasshoppers in controlled trials due to this . Mimicry further bolsters defenses, with some species engaging in by resembling unpalatable or evasive models; for example, the grasshopper Arphia conspersa mimics the flight path and appearance of the elusive alfalfa butterfly Colias eurytheme, confusing predators and reducing attack rates. In swarming phases, aggregative mimicry amplifies collective warning signals, making groups appear more threatening through synchronized displays and increased density. Ontogenetic shifts in defenses occur as grasshoppers develop, with nymphs relying more on and immobility to avoid detection due to limited flight capability, while adults transition to active flight escapes and bolder displays for rapid evasion. In solitarious locusts, early instars prioritize cryptic foraging to minimize visibility, whereas gregarious adults leverage mobility and . In aposematic species like Romaleids, nymphs may exhibit bright coloration and gregariousness for , shifting to in adulthood as body size and levels increase.

Threats and conservation

Climate change impacts

Climate change is driving significant phenological shifts in grasshopper populations, primarily through warmer temperatures advancing key life stages. In , insect spring and summer phenological events, including grasshopper emergence, have advanced by an average of 2.5 days per decade since the , resulting in earlier adult emergence by approximately 10 days over four decades. In , early-season grasshopper exhibit greater phenological advancement compared to late-season , with emergence timing shifting by up to several weeks in response to prolonged warm periods at higher elevations. These shifts often extend breeding seasons, allowing multiple generations in regions where warmer conditions prolong suitable developmental windows. Range expansions are a prominent response among grasshoppers adapting to warming climates, with poleward migrations documented in temperate regions. In , many grasshopper species have expanded northward by tens to hundreds of kilometers since the late , tracking suitable thermal habitats amid rising temperatures. Upward altitudinal shifts have also been observed in grasshopper populations, enabling access to cooler conditions at higher elevations, though this is constrained by topographic limits in mountainous areas. Warmer and more variable weather patterns are intensifying locust swarm formation, as climate-driven extremes like droughts followed by heavy rainfall create ideal breeding conditions. The 2019–2021 desert locust plagues across , the , and , which affected 23 countries and devastated vegetation, were exacerbated by ocean warming that fueled cyclones and unseasonal rains. Such outbreaks are projected to become more frequent with continued , as extended warm periods favor gregarious phase transitions in locust species. Physiological stresses from pose direct threats to grasshopper survival, particularly exceeding tolerance thresholds and increased risk. Most grasshopper species experience lethal internal temperatures above 40–48°C, beyond which cellular damage occurs rapidly during heatwaves. In aridifying regions, reduced amplifies stress, lowering tolerance and increasing mortality, as reduces the insects' ability to regulate body temperature through . Modeling studies aligned with IPCC scenarios predict substantial grasshopper losses in temperate zones by 2100, driven by unsuitability from shifting climates. Under high-emission pathways like RCP 8.5, 20–30% of , including many grasshoppers, face risk in temperate regions due to phenological mismatches and range contractions. These projections highlight vulnerabilities for late-season and high-elevation , where warming outpaces .

Conservation status

The conservation status of grasshopper species worldwide remains poorly documented, with the majority classified as Data Deficient on the IUCN Red List due to insufficient monitoring and taxonomic data. Of the approximately 1,501 Orthoptera species (including grasshoppers) assessed globally, a significant proportion lack comprehensive evaluations, though regional assessments reveal notable threats; for instance, in Europe, 25.7% of 1,082 evaluated species are threatened with extinction. Recent discoveries, such as 16 new grasshopper species identified in U.S. and Mexican deserts in 2025, underscore ongoing taxonomic gaps and the urgency for expanded assessments. The IUCN SSC Grasshopper Specialist Group has prioritized assessments for over 200 species, identifying around 10% as Vulnerable or higher, but emphasizes that under-assessment hinders accurate global estimates; as of 2024-2025, additional national assessments include 50 species in Albania and 60 in Greece. Key threats to grasshoppers include habitat loss from agricultural expansion and intensification, which fragments ecosystems essential for many species. Pesticide applications, often targeted at outbreaks, cause widespread non-target mortality and degrade habitats across rangelands. Competition from further exacerbates declines by altering resource availability in native habitats. Endemic hotspots for threatened grassland specialists occur in prairie and steppe regions, where habitat specialists face heightened risks; for example, the Lake Huron grasshopper (Trimerotropis huroniana) is listed as Threatened due to dune and prairie habitat loss in North American Great Lakes regions. In European steppes, the Crau plain grasshopper (Prionotropis rhodanica) is Endangered, confined to remnant calcareous grasslands threatened by urbanization and agriculture. Conservation actions focus on establishing and managing to safeguard habitats, such as nature reserves that prevent grassland conversion and maintain ecological integrity for grasshopper assemblages. In migratory hotspots like the ecosystem, broader networks support populations of swarming by preserving migratory corridors. Efforts also promote biocontrol alternatives, including reduced agent area treatments (RAATs) that minimize chemical use while targeting outbreaks. Research gaps persist in assessing , particularly post-2020, to inform population resilience and translocation strategies amid ongoing habitat pressures.

Relationship with humans

As pests

Grasshoppers pose significant threats to worldwide, primarily through defoliation of such as grains, , and , leading to substantial yield reductions and economic losses. In severe outbreaks, they consume vast amounts of vegetation, stripping fields bare and compromising , particularly in arid and semi-arid regions. Annual global economic losses from grasshopper and pests are estimated at around $2.2 billion, encompassing direct crop damage and control costs. For instance, during the 2020 outbreak in , approximately 2.4 million hectares of farmland and pasture were treated to mitigate damage. Among the most damaging species are the American grasshopper (Schistocerca americana), prevalent in North American crops, and the differential grasshopper (Melanoplus differentialis), which targets a wide range of field crops and rangelands. These species thrive in warm, dry conditions and can rapidly multiply, exacerbating damage during population surges. Outbreaks are largely weather-driven, often triggered by droughts that concentrate populations followed by rains that boost and vegetation for feeding. Monitoring relies on technologies, including (NDVI) data, to detect favorable s and predict infestation risks early. Control strategies encompass chemical, cultural, and biological approaches to manage populations effectively. Chemical insecticides like are applied via sprays or baits for rapid knockdown during high-density outbreaks. Cultural methods, such as to destroy egg pods in overwintering sites and , reduce habitat suitability. Biological controls include the protozoan pathogen Nosema locustae, which infects and weakens grasshoppers over time when disseminated in baits. Integrated pest management (IPM) programs integrate these tactics, emphasizing economic thresholds—such as 2-3 grasshoppers per square meter in crops—to guide spraying decisions and minimize resistance development. This approach promotes sustainable suppression while preserving beneficial and reducing environmental impacts.

As food

Grasshoppers are consumed as a nutritious source in various cultures, offering a high-protein alternative to traditional meats with a lower environmental . On a dry weight basis, they typically contain 50-65% crude protein, along with essential fatty acids, vitamins such as B12, and minerals like calcium, , iron, and , while being low in carbohydrates. This profile positions grasshoppers as a sustainable protein option, requiring fewer resources like water and land compared to production, potentially aiding global . Culinary traditions featuring grasshoppers date back centuries in regions like and . In , chapulines—grasshoppers of the genus —are harvested seasonally, toasted on a comal, and seasoned with , , , and , serving as a popular snack or topping for tacos and in and surrounding areas. In , (winged grasshoppers, often Ruspolia differens) are collected during rainy seasons, deep-fried with onions, , and spices, and enjoyed as a crispy, protein-rich that provides an affordable meat substitute. Approximately two billion people worldwide incorporate , including grasshoppers, into their diets, primarily in , , and . Harvesting methods range from wild collection to controlled farming to meet demand. Wild grasshoppers are often gathered at night using lights or nets during peak seasons, particularly stages for optimal , while farming operations in utilize vertical systems or enclosures to rear species like the Bombay (Patanga succincta), ensuring year-round supply. Processing techniques, such as , , or , eliminate pathogens and parasites, making them safe for consumption when following good manufacturing practices. The global edible insect market, including grasshoppers, is expanding rapidly, valued at around USD 1 billion in 2025 (Mordor Intelligence, November 2025) and projected to grow due to increasing interest in sustainable proteins. Grasshoppers represent a significant portion of this sector, with their market expected to contribute substantially through products like flours and snacks. Despite these benefits, challenges persist in widespread adoption. Grasshoppers can trigger allergic reactions in individuals sensitive to shellfish due to shared proteins like tropomyosin, necessitating clear labeling and consumer education. Scaling production faces hurdles such as optimizing feed efficiency, managing microbial risks, and establishing regulatory frameworks for commercial farming.

Cultural and symbolic roles

In Western , the grasshopper often symbolizes and the consequences of failing to prepare for the future, as depicted in Aesop's "," where the carefree grasshopper starves in winter after mocking the diligent ant's labor. This narrative, originating from oral traditions and later compiled in written collections around the 6th century BCE, imparts a moral lesson on foresight and industriousness, contrasting the grasshopper's short-term pleasures with long-term hardship. In Native American traditions, grasshoppers represent , abundance, and , with some tribes viewing their presence as a sign of forthcoming plenty or successful hunts. Legends from various indigenous groups, such as the and Zuni, portray grasshoppers as messengers or harbingers of favorable conditions, emphasizing themes of and communal well-being. Religiously, grasshoppers and locusts (swarming grasshoppers) symbolize divine judgment and destruction in the , particularly in the , where the eighth plague unleashes locusts to devour Egypt's crops as punishment for Pharaoh's refusal to free the . This event, described in 10:12-15, portrays locusts as instruments of God's sovereignty, overwhelming the land in a thick darkness and stripping vegetation bare to demonstrate Yahweh's power over creation. In contrast, religious and folk beliefs regard grasshoppers as auspicious symbols of harvest abundance, longevity, and joy, often associated with prosperity due to their prolific presence in fertile fields during bountiful seasons. Across , grasshoppers frequently appear as figures, embodying cunning and mischief in tales that challenge social norms and highlight the unpredictability of life. In stories from , the grasshopper aids the in deceptive schemes, such as feigning grief to gain food, illustrating themes of wit over strength and the moral ambiguities of survival. Similarly, in Mesoamerican myths, particularly among the , grasshoppers served as omens of and when solitary, but their swarming form as locusts foretold , reflecting a dual role in and cosmology tied to agricultural cycles. In contemporary contexts, grasshoppers have emerged as environmental icons in efforts, valued as bioindicators of and in grasslands and rangelands. Species assemblages of grasshoppers are used to assess habitat quality, with diverse communities signaling intact ecological networks, while declines indicate degradation from factors like or . Certain grasshopper species even function as flagship taxa in campaigns to protect threatened habitats, underscoring their role in broader preservation. Cross-culturally, grasshoppers exhibit stark variations, often embodying a between and valued resource; in sub-Saharan African societies, they are reviled as crop-destroying plagues yet celebrated as seasonal delicacies that signify communal feasts and nutritional abundance. This ambivalence extends globally, where agricultural contexts frame them as threats to yields, while in regions like and honors their ecological contributions to and as omens of renewal.

In art, literature, and media

Grasshoppers have appeared in Japanese poetry as symbols of transience and seasonal change, often capturing their fleeting presence in nature. For instance, the poet wrote haiku like "giddy grasshopper / take care... do not leap / and crush these pearls of dewdrop," evoking the insect's playful yet fragile existence. Another example from Issa highlights auditory elements: "a cool breeze, / the grasshopper singing / with all his might," integrating sound into the 's essence of momentary observation. These depictions reflect haiku's roots in capturing ephemeral natural phenomena, with grasshoppers embodying summer's vitality. In ancient Egyptian art, grasshoppers featured prominently in hieroglyphs and amulets, representing both fertility and multitudes of minor threats. The hieroglyph for grasshopper (znḥm) appeared in inscriptions, often symbolizing numerous but individually weak enemies of Egypt, as seen in tomb carvings from the Old Kingdom. Amulets shaped like grasshoppers, crafted from faience or stone, were worn for protection and aesthetic purposes, underscoring their dual role as emblems of beauty and natural cycles. A notable example is a 4300-year-old stone carving from the Tomb of Kagemni at Saqqara, depicting a grasshopper alongside other insects like frogs and dragonflies, illustrating early naturalistic motifs in Egyptian decorative art. In Western visual art, grasshoppers transitioned from scientific illustrations to embedded elements in paintings. During the , entomological works like those in Maria Sibylla Merian's detailed engravings portrayed grasshoppers with scientific precision, aiding early studies of amid the Enlightenment's focus on . By the late , inadvertently incorporated a real grasshopper into his 1889 painting Olive Trees, where the insect became trapped in the wet paint during an outdoor session in Saint-Rémy, later discovered via microscopy in 2017. In , has elevated grasshoppers to subjects of intricate portraiture, as in Thomas Shahan's handheld captures using specialized lenses to reveal textured exoskeletons and patterns, blending scientific observation with artistic abstraction. Animated films have anthropomorphized grasshoppers as antagonists, drawing on their real-world swarming behavior. In Pixar's 1998 , the grasshopper gang led by extorts food from an , portraying them as tyrannical bullies whose collective threat underscores themes of unity against oppression. This depiction amplifies the insect's ecological role as a crop raider into a of power dynamics. In television, episode "Penny-Wiseguys" (2012) features a swarm of grasshoppers escaping Lisa's basement tank, overwhelming a character in a comedic nod to biblical plagues and insect proliferation. Folk music traditions have woven grasshoppers into moralistic tales and playful tunes, often adapting Aesop's of industry versus idleness. The English folk song "Grasshoppers Three" describes three grasshoppers fiddling merrily: "Grasshoppers three a-fiddling went, / Hey ho! Never be still," using the insects to evoke carefree summer rhythms in children's repertoire. Leon Rosselson's "The Ant and the Grasshopper" reimagines the in a folk , with the grasshopper's song symbolizing unburdened joy amid societal critique. In video games, grasshoppers inspire mechanics centered on leaping, as in the BattleTech series where the Grasshopper mech uses jump jets for 90-meter bounds, mimicking the insect's propulsion for tactical mobility in sci-fi combat simulations. Depictions of grasshoppers in evolved from 18th-century entomological to surrealist , mirroring broader shifts in scientific and artistic paradigms. Early illustrations in works like those of Jan van Kessel emphasized anatomical accuracy for classification, aligning with . By the , surrealists like incorporated grasshopper motifs into dreamlike compositions as symbols of fear and . This progression highlights how grasshoppers shifted from objects of empirical study to vessels for exploring the irrational and subconscious in .

Technological applications

Grasshoppers have inspired advancements in through biomimicry of their powerful jumping mechanisms. Researchers at the (EPFL) developed a 7-gram microrobot in 2008 that replicates the grasshopper's leg structure, using elastic springs to store and release for jumps up to 27 times its height, achieving a record at the time for untethered jumping robots. This design leverages the grasshopper's catapult-like hind legs, which enable explosive propulsion, to create compact, energy-efficient robots suitable for in rough terrain. In , grasshoppers have been engineered as biohybrid sensors by implanting electrodes into their brains to monitor neural responses to odors. In 2020, scientists at demonstrated that grasshoppers could distinguish explosive vapors like from non-explosive scents, with distinct brain activity patterns emerging within 500 milliseconds of exposure, funded by the U.S. . This approach exploits the ' sensitive , potentially enabling swarms of low-cost, mobile detectors for landmine clearance or screening. The "grasshopper" linkage, a variant of the Scott mechanism, provides approximate straight-line motion in applications. Named for its resemblance to a grasshopper's , this uses a sliding to generate near-linear paths over a limited range, historically applied in beam engines and more recently in precision mechanisms. While specific implementations in vehicle suspensions are less documented, straight-line linkages like the grasshopper design contribute to suspension systems by facilitating controlled vertical motion and stability in rough conditions. Biomedically, grasshopper abdominal secretions have shown potential in , rooted in traditional where they are applied topically to accelerate repair. A 2015 study confirmed that secretions from like Chorthippus parallelus reduce and promote faster epithelialization in rat models, attributed to and enzymes. Additionally, enzymes from grasshopper guts, such as cellulases and xylanases in Oxya velox, exhibit high activity for breaking down plant biomass, offering prospects for biotechnological applications in production and waste degradation. in grasshoppers further enhance these enzymes' efficiency compared to other , supporting scalable . In , grasshopper serve as models for studying flight control circuits, with recent research mapping descending neurons that integrate sensory inputs for locomotion. A study on the (Schistocerca gregaria, a grasshopper relative) identified neural pathways in the that activate during flight and stimuli, revealing command-like neurons for steering and stability. Although has been more prevalent in , its application to orthopterans like grasshoppers post-2020 builds on electrophysiological data from the dorsal unpaired median (DUM) neurons, which modulate flight motor patterns via neuromodulators. These insights inform bio-inspired algorithms for autonomous drone navigation.