68-543: Grasshoppers are a group of insects belonging to the suborder Caelifera . 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 typically ground-dwelling insects with powerful hind legs which allow them to escape from threats by leaping vigorously. Their front legs are shorter and used for grasping food. As hemimetabolous insects, they do not undergo complete metamorphosis ; they hatch from an egg into
136-500: A brain and a ventral nerve cord . Most insects reproduce by laying eggs . Insects breathe air through a system of paired openings along their sides, connected to small tubes that take air directly to the tissues. The blood therefore does not carry oxygen; it is only partly contained in vessels, and some circulates in an open hemocoel . Insect vision is mainly through their compound eyes , with additional small ocelli . Many insects can hear, using tympanal organs , which may be on
204-612: A nymph or "hopper" which undergoes five moults , becoming more similar to the adult insect at each developmental stage. The grasshopper hears through the tympanal organ which can be found in the first segment of the abdomen attached to the thorax; while its sense of vision is in the compound eyes, a change in light intensity is perceived in the simple eyes (ocelli). At high population densities and under certain environmental conditions, some grasshopper species can change colour and behavior and form swarms. Under these circumstances, they are known as locusts . Grasshoppers are plant-eaters, with
272-552: A common name for the suborder in general, modern sources restrict it to the more "evolved" families . They may be placed in the infraorder Acrididea and have been referred to as "short-horned grasshoppers" in older texts to distinguish them from the also-obsolete term "long-horned grasshoppers" (now bush-crickets or katydids) with their much longer antennae . The phylogeny of the Caelifera, based on mitochondrial ribosomal RNA of thirty-two taxa in six out of seven superfamilies,
340-419: 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. They protect themselves from predators by camouflage ; when detected, many species attempt to startle the predator with a brilliantly coloured wing flash while jumping and (if adult) launching themselves into the air, usually flying for only
408-563: A hundred species, are marine. Insects such as snow scorpionflies flourish in cold habitats including the Arctic and at high altitude. Insects such as desert locusts , ants, beetles, and termites are adapted to some of the hottest and driest environments on earth, such as the Sonoran Desert . Insects form a clade , a natural group with a common ancestor, among the arthropods . A phylogenetic analysis by Kjer et al. (2016) places
476-453: A long relationship with humans. Swarms of locusts can have devastating effects and cause famine, having done so since Biblical times . Even in smaller numbers, the insects can be serious pests. They are used as food in countries such as Mexico and Indonesia. They feature in art, symbolism and literature. The study of grasshopper species is called acridology . Grasshoppers belong to the suborder Caelifera. Although "grasshopper" has been used as
544-511: A nearby body of water where it drowns, thus enabling the parasite to continue with the next stage of its life cycle , which takes place in water. Grasshoppers are affected by diseases caused by bacteria , viruses , fungi and protozoa . The bacteria Serratia marcescens and Pseudomonas aeruginosa have both been implicated in causing disease in grasshoppers, as has the entomopathogenic fungus Beauveria bassiana . This widespread fungus has been used to control various pest insects around
612-625: A nearly immobile pupa . Insects that undergo three-stage metamorphosis lack a pupa, developing through a series of increasingly adult-like nymphal stages. The higher level relationship of the insects is unclear. Fossilized insects of enormous size have been found from the Paleozoic Era, including giant dragonfly-like insects with wingspans of 55 to 70 cm (22 to 28 in). The most diverse insect groups appear to have coevolved with flowering plants . Adult insects typically move about by walking and flying; some can swim. Insects are
680-501: A pair of cerci and segments ten and eleven have the reproductive organs. Female grasshoppers are normally larger than males , with short ovipositors. The name of the suborder "Caelifera" comes from the Latin and means chisel-bearing , referring to the shape of the ovipositor. The grasshopper's auditory organs are located on its abdomen, rather than on its head. These organs consist of a pair of membranes, each positioned on either side of
748-453: A pair of thread-like antennae that are sensitive to touch and smell. The downward-directed mouthparts are modified for chewing and there are two sensory palps in front of the jaws . The thorax and abdomen are segmented and have a rigid cuticle made up of overlapping plates composed of chitin . The three fused thoracic segments bear three pairs of legs and two pairs of wings. The forewings, known as tegmina , are narrow and leathery while
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#1732780147800816-401: A pod in the ground near food plants, generally in the summer. After laying the eggs, she covers the hole with soil and litter. Some, like the semi-aquatic Cornops aquaticum , deposit the pod directly into plant tissue. The eggs in the pod are glued together with a froth in some species. After a few weeks of development, the eggs of most species in temperate climates go into diapause , and pass
884-408: A short distance. Other species such as the rainbow grasshopper have warning coloration which deters predators. Grasshoppers are affected by parasites and various diseases, and many predatory creatures feed on both nymphs and adults. The eggs are subject to attack by parasitoids and predators. Grasshoppers are diurnal insects, meaning they are most active during the day time. Grasshoppers have had
952-453: A typical insect nervous system, and have an extensive set of external sense organs. 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 also three simple eyes ( ocelli ) on the forehead which can detect light intensity, a pair of antennae containing olfactory (smell) and touch receptors, and mouthparts containing gustatory (taste) receptors. At
1020-525: A variety of ways. Male moths can sense the pheromones of female moths over great distances. Other species communicate with sounds: crickets stridulate , or rub their wings together, to attract a mate and repel other males. Lampyrid beetles communicate with light. Humans regard many insects as pests , especially those that damage crops, and attempt to control them using insecticides and other techniques. Others are parasitic , and may act as vectors of diseases . Insect pollinators are essential to
1088-454: Is a "heavy, bloated, sluggish insect" that makes no attempt to hide; it has a bright red abdomen. A Cercopithecus monkey that ate other grasshoppers refused to eat the species. 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. Grasshoppers are occasionally depicted in artworks, such as
1156-404: Is a long slender worm that infects grasshoppers, living in the insects' hemocoel . Adult worms lay eggs on plants and the host becomes infected when the foliage is eaten. Spinochordodes tellinii and Paragordius tricuspidatus are parasitic worms that infect grasshoppers and alter the behaviour of their hosts. When the worms are sufficiently developed, the grasshopper is persuaded to leap into
1224-428: Is common to have acrocentric chromosomes with a fundamental number (FN), i.e. number of chromosome arms, of 23♂/24♀. However, chromosomal rearrangements are frequently found as deviations from the standard acrocentric karyotype . In the subfamily Ommexechinae most species show a unique karyotype (2n = 23♂/24♀, FN = 25♂/26♀) due to the occurrence of a large autosomal pair (L1) with submetacentric morphology. There
1292-581: Is for grasses, including many cereals grown as crops. The digestive system is typical of insects, with Malpighian tubules discharging into the midgut. Carbohydrates are digested mainly in the crop, while proteins are digested in the ceca of the midgut. Saliva is abundant but largely free of enzymes, helping to move food and Malpighian secretions along the gut. Some grasshoppers possess cellulase , which by softening plant cell walls makes plant cell contents accessible to other digestive enzymes. Grasshoppers can also be cannibalistic when swarming. Grasshoppers have
1360-415: Is performed using tracheae , air-filled tubes, which open at the surfaces of the thorax and abdomen through pairs of valved spiracles . Larger insects may need to actively ventilate their bodies by opening some spiracles while others remain closed, using abdominal muscles to expand and contract the body and pump air through the system. Grasshoppers jump by extending their large back legs and pushing against
1428-470: Is shown as a cladogram . The Ensifera (crickets, etc. ), Caelifera and all the superfamilies of grasshoppers except " Pamphagoidea " appear to be monophyletic . [6 superfamilies] [REDACTED] Tridactyloidea [REDACTED] Tetrigoidea [REDACTED] Eumastacoidea [REDACTED] Proscopioidea [REDACTED] Pneumoroidea [REDACTED] Pyrgomorphoidea [REDACTED] Acridoidea [REDACTED] In evolutionary terms,
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#17327801478001496-486: Is the basis for a bait-based commercial microbial pesticide. Various other microsporidians and protozoans are found in the gut. Grasshoppers exemplify a range of anti-predator adaptations , enabling them to avoid detection, to escape if detected, and in some cases to avoid being eaten if captured. Grasshoppers are often camouflaged to avoid detection by predators that hunt by sight; some species can change their coloration to suit their surroundings. Several species such as
1564-456: Is the largest superfamily of grasshoppers in the order Orthoptera with over 11,000 species found on every continent except Antarctica. Orthoptera Species File includes the following families: Among the families Acrididae , Ommexechidae and Romaleidae there is reported to be chromosomal stability with a high frequency of species harbouring diploid number (2n) of 23♂/24♀ chromosomes. In species of Acrididae and Romaleidae it
1632-622: The Dutch Golden Age painter Balthasar van der Ast 's still life oil painting, Flowers in a Vase with Shells and Insects , c. 1630, now in the National Gallery, London , though the insect may be a bush-cricket. Another orthopteran is found in Rachel Ruysch 's still life Flowers in a Vase , c. 1685. The seemingly static scene is animated by a "grasshopper on the table that looks about ready to spring", according to
1700-853: The Latin word insectum from in , "cut up", as insects appear to be cut into three parts. The Latin word was introduced by Pliny the Elder who calqued the Ancient Greek word ἔντομον éntomon "insect" (as in entomology ) from ἔντομος éntomos "cut in pieces"; this was Aristotle 's term for this class of life in his biology , also in reference to their notched bodies. The English word insect first appears in 1601 in Philemon Holland 's translation of Pliny. In common speech, insects and other terrestrial arthropods are often called bugs . Entomologists to some extent reserve
1768-2239: The Paraneoptera , and Kjer et al. 2016 for the Holometabola . The numbers of described extant species (boldface for groups with over 100,000 species) are from Stork 2018. Archaeognatha (hump-backed/jumping bristletails, 513 spp) [REDACTED] Zygentoma (silverfish, firebrats, fishmoths, 560 spp) [REDACTED] Odonata (dragonflies and damselflies, 5,899 spp) [REDACTED] Ephemeroptera (mayflies, 3,240 spp) [REDACTED] Zoraptera (angel insects, 37 spp) [REDACTED] Dermaptera (earwigs, 1,978 spp) [REDACTED] Plecoptera (stoneflies, 3,743 spp) [REDACTED] Orthoptera (grasshoppers, crickets, katydids, 23,855 spp) [REDACTED] Grylloblattodea (ice crawlers, 34 spp) [REDACTED] Mantophasmatodea (gladiators, 15 spp) [REDACTED] Phasmatodea (stick insects, 3,014 spp) [REDACTED] Embioptera (webspinners, 463 spp) [REDACTED] Mantodea (mantises, 2,400 spp) [REDACTED] Blattodea (cockroaches and termites, 7,314 spp) [REDACTED] Psocodea (book lice, barklice and sucking lice, 11,000 spp) [REDACTED] [REDACTED] Hemiptera (true bugs, 103,590 spp) [REDACTED] Thysanoptera (thrips, 5,864 spp) [REDACTED] Hymenoptera (sawflies, wasps, bees, ants, 116,861 spp) [REDACTED] Strepsiptera (twisted-wing flies, 609 spp) [REDACTED] Coleoptera (beetles, 386,500 spp) [REDACTED] Raphidioptera (snakeflies, 254 spp) [REDACTED] Neuroptera (lacewings, 5,868 spp) [REDACTED] Megaloptera (alderflies and dobsonflies, 354 spp) [REDACTED] Lepidoptera (butterflies and moths, 157,338 spp) [REDACTED] Trichoptera (caddisflies, 14,391 spp) [REDACTED] Diptera (true flies, 155,477 spp) [REDACTED] Mecoptera (scorpionflies, 757 spp) [REDACTED] Siphonaptera (fleas, 2,075 spp) [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] Acridoidea See Classification . Acridoidea
1836-439: The class Insecta . They are the largest group within the arthropod phylum . Insects have a chitinous exoskeleton , a three-part body ( head , thorax and abdomen ), three pairs of jointed legs , compound eyes , and a pair of antennae . Insects are the most diverse group of animals, with more than a million described species ; they represent more than half of all animal species. The insect nervous system consists of
1904-438: The mechanical power produced by their muscles. The jump is a three-stage process. First, the grasshopper fully flexes the lower part of the leg (tibia) against the upper part (femur) by activating the flexor tibiae muscle (the back legs of the grasshopper in the top photograph are in this preparatory position). Second, there is a period of co-contraction in which force builds up in the large, pennate extensor tibiae muscle, but
1972-498: The 1971 tokusatsu series Kamen Rider primarily carry a grasshopper motif (for example Kamen Rider Black's Batta Man form), which continues to serve as the baseline visual template for most entries in the media franchise it has given birth to since. Grasshoppers are sometimes used as symbols. During the Greek Archaic Era , the grasshopper was the symbol of the polis of Athens , possibly because they were among
2040-561: The Eumastacidae, Tetrigidae and Tridactylidae appeared in the Cretaceous , though some insects that might belong to the last two of these groups are found in the early Jurassic . 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. This information is not available from fossil specimens, and
2108-623: The Hemiptera (true bugs), Lepidoptera (butterflies and moths), Diptera (true flies), Hymenoptera (wasps, ants, and bees), and Coleoptera (beetles), each with more than 100,000 described species. Insects are distributed over every continent and almost every terrestrial habitat. There are many more species in the tropics , especially in rainforests , than in temperate zones. The world's regions have received widely differing amounts of attention from entomologists. The British Isles have been thoroughly surveyed, so that Gullan and Cranston 2014 state that
Grasshopper - Misplaced Pages Continue
2176-506: The Lentulids are wingless. Pneumoridae are native to Africa, particularly southern Africa, and are distinguished by the inflated abdomens of the males. Grasshoppers have the typical insect body plan of head, thorax , and abdomen . The head is held vertically at an angle to the body, with the mouth at the bottom. The head bears a large pair of compound eyes which give all-round vision, three simple eyes which can detect light and dark, and
2244-707: The building was for a while the headquarters of the Guardian Royal Exchange , but the company declined to use the symbol for fear of confusion with the locust. 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". Insect Insects (from Latin insectum ) are hexapod invertebrates of
2312-400: The chameleon grasshopper ( Kosciuscola tristis ), where males may fight on top of ovipositing females; engaging in leg grappling, biting, kicking and mounting. The newly emerged female grasshopper has a preoviposition period of a week or two while she increases in weight and her eggs mature. After mating, the female of most species digs a hole with her ovipositor and lays a batch of eggs in
2380-598: The elastic structures, rather than by further shortening of the extensor muscle. In this way the stiff cuticle acts like the elastic of a catapult , or the bow of a bow-and-arrow. Energy is put into the store at low power by slow but strong muscle contraction, and retrieved from the store at high power by rapid relaxation of the mechanical elastic structures. Male grasshoppers spend much of the day stridulating , singing more actively under optimal conditions and being more subdued when conditions are adverse; females also stridulate, but their efforts are insignificant when compared to
2448-422: The escape jump in particular there is strong selective pressure to maximize take-off velocity, since this determines the range. This means that the legs must thrust against the ground with both high force and a high velocity of movement. A fundamental property of muscle is that it cannot contract with high force and high velocity at the same time. Grasshoppers overcome this by using a catapult mechanism to amplify
2516-531: The family Acrididae. Swarming behaviour is a response to overcrowding. Increased tactile stimulation of the hind legs causes an increase in levels of serotonin . This causes the grasshopper to change colour, feed more and breed faster. The transformation of a solitary individual into a swarming one is induced by several contacts per minute over a short period. Following this transformation, under suitable conditions dense nomadic bands of flightless nymphs known as "hoppers" can occur, producing pheromones which attract
2584-646: The females also stridulate. 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. Ensiferans have antennae that can be much longer than the body and have at least 20–24 segments, while caeliferans have fewer segments in their shorter, stouter antennae. Most grasshoppers are polyphagous , eating vegetation from multiple plant sources, but some are omnivorous and also eat animal tissue and animal faeces. In general their preference
2652-443: The first abdominal segment and tucked under the wings. Known as tympanal organs, these simple eardrums vibrate in response to sound waves, enabling the grasshopper to hear the songs of other grasshoppers. 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). These sounds are produced mainly by males to attract females, though in some species
2720-403: The front end of the abdomen there is a pair of tympanal organs for sound reception. 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. There are special receptors ( campaniform sensillae ) embedded in the cuticle of
2788-473: The fungal spores liberated from the corpse. The fungal pathogen Metarhizium acridum is found in Africa, Australia and Brazil where it has caused epizootics in grasshoppers. It is being investigated for possible use as a microbial insecticide for locust control. The microsporidian fungus Nosema locustae , once considered to be a protozoan, can be lethal to grasshoppers. It has to be consumed by mouth and
Grasshopper - Misplaced Pages Continue
2856-473: The gallery curator Betsy Wieseman, with other invertebrates including a spider, an ant, and two caterpillars. Grasshoppers are also featured in cinema. The 1957 film Beginning of the End portrayed giant grasshoppers attacking Chicago . In the 1998 Disney / Pixar animated film A Bug's Life , the antagonists are a gang of grasshoppers, with their leader Hopper serving as the main villain. The protagonists of
2924-437: The hindwings are large and membranous, the veins providing strength. The legs are terminated by claws for gripping. The hind leg is particularly powerful. The legs of these species are so powerful that they can jump quite a long distance. they also use this to flee from danger. The femur is robust and has several ridges where different surfaces join and the inner ridges bear stridulatory pegs in some species. The posterior edge of
2992-556: The hooded leaf grasshopper Phyllochoreia ramakrishnai (Eumastacoidea) are detailed mimics of leaves. Stick grasshoppers (Proscopiidae) mimic wooden sticks in form and coloration. Grasshoppers often have deimatic patterns on their wings, giving a sudden flash of bright colours that may startle predators long enough to give time to escape in a combination of jump and flight. Some species are genuinely aposematic , having both bright warning coloration and sufficient toxicity to dissuade predators. Dictyophorus productus (Pyrgomorphidae)
3060-608: The insects among the Hexapoda , six-legged animals with segmented bodies; their closest relatives are the Diplura (bristletails). Collembola (springtails) [REDACTED] Protura (coneheads) [REDACTED] Diplura (two-pronged bristletails) [REDACTED] Insecta (=Ectognatha) [REDACTED] The internal phylogeny is based on the works of Wipfler et al. 2019 for the Polyneoptera , Johnson et al. 2018 for
3128-430: 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 largest recorded locust swarm was one formed by the now-extinct Rocky Mountain locust in 1875; the swarm was 1,800 miles (2,900 km) long and 110 miles (180 km) wide, and one estimate puts
3196-404: The leg. The extensor muscle contraction is quite slow (almost isometric), which allows it to develop high force (up to 14 N in the desert locust), but because it is slow only low power is needed. The third stage of the jump is the trigger relaxation of the flexor muscle, which releases the tibia from the flexed position. The subsequent rapid tibial extension is driven mainly by the relaxation of
3264-406: The legs or other parts of the body. Their sense of smell is via receptors, usually on the antennae and the mouthparts. Nearly all insects hatch from eggs . Insect growth is constrained by the inelastic exoskeleton, so development involves a series of molts . The immature stages often differ from the adults in structure, habit and habitat. Groups that undergo four-stage metamorphosis often have
3332-513: The legs that sense pressure and cuticle distortion. There are internal "chordotonal" sense organs specialized to detect position and movement about the joints of the exoskeleton. The receptors convey information to the central nervous system through sensory neurons, and most of these have their cell bodies located in the periphery near the receptor site itself. Like other insects, grasshoppers have an open circulatory system and their body cavities are filled with haemolymph . A heart-like structure in
3400-465: The males. Late-stage male nymphs can sometimes be seen making stridulatory movements, although they lack the equipment to make sounds, demonstrating the importance of this behavioural trait. 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
3468-574: The most common insects on the dry plains of Attica . Native Athenians for a while wore golden grasshopper brooches to symbolise that they were of pure Athenian lineage with no foreign ancestors. In addition, Peisistratus hung the figure of a kind of grasshopper before the Acropolis of Athens as apotropaic magic . Another symbolic use of the grasshopper is Sir Thomas Gresham 's gilded grasshopper in Lombard Street, London , dating from 1563;
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#17327801478003536-402: The name "bugs" for a narrow category of " true bugs ", insects of the order Hemiptera , such as cicadas and shield bugs . Other terrestrial arthropods, such as centipedes , millipedes , woodlice , spiders , mites and scorpions , are sometimes confused with insects, since they have a jointed exoskeleton. Adult insects are the only arthropods that ever have wings, with up to two pairs on
3604-989: The number of locusts involved at 3.5 trillion. An adult desert locust can eat about 2 g (0.1 oz) of plant material each day, so the billions of insects in a large swarm can be very destructive, stripping all the foliage from plants in an affected area and consuming stems, flowers, fruits, seeds and bark. Grasshoppers have a wide range of predators at different stages of their lives; eggs are eaten by bee-flies , ground beetles and blister beetles ; hoppers and adults are taken by other insects such as ants and , robber flies and sphecid wasps , by spiders , and by many birds and small mammals including dogs and cats. The eggs and nymphs are under attack by parasitoids including blow flies , flesh flies, and tachinid flies . External parasites of adults and nymphs include mites. Female grasshoppers parasitised by mites produce fewer eggs and thus have fewer offspring than unaffected individuals. The grasshopper nematode ( Mermis nigrescens )
3672-791: The oldest living group of chewing herbivorous insects. The most diverse superfamily is the Acridoidea , with around 8,000 species. The two main families in this are the Acrididae (grasshoppers and locusts) with a worldwide distribution, and the Romaleidae (lubber grasshoppers), found chiefly in the New World. The Ommexechidae and Tristiridae are South American, and the Lentulidae, Lithidiidae and Pamphagidae are mainly African. The Pauliniids are nocturnal and can swim or skate on water, and
3740-554: The only invertebrates that can achieve sustained powered flight; insect flight evolved just once. Many insects are at least partly aquatic , and have larvae with gills; in some species, the adults too are aquatic. Some species, such as water striders , can walk on the surface of water. Insects are mostly solitary, but some, such as bees , ants and termites , are social and live in large, well-organized colonies . Others, such as earwigs , provide maternal care, guarding their eggs and young. Insects can communicate with each other in
3808-469: The palaeontological taxonomy is founded principally on the venation of the hindwings. The Caelifera includes some 2,400 valid genera and about 11,000 known species. Many undescribed species probably exist, especially in tropical wet forests . The Caelifera have a predominantly tropical distribution with fewer species known from temperate zones, but most of the superfamilies have representatives worldwide. They are almost exclusively herbivorous and are probably
3876-535: The reproduction of many flowering plants and so to their ecosystems. Many insects are ecologically beneficial as predators of pest insects, while a few provide direct economic benefit. Two species in particular are economically important and were domesticated many centuries ago: silkworms for silk and honey bees for honey . Insects are consumed as food in 80% of the world's nations, by people in roughly 3000 ethnic groups. Human activities are having serious effects on insect biodiversity . The word insect comes from
3944-479: The song can serve to limit dispersal and guide others to favourable habitat. The generalised song can vary in phraseology and intensity, and is modified in the presence of a rival male, and changes again to a courtship song when a female is nearby. In male grasshoppers of the family Pneumoridae, the enlarged abdomen amplifies stridulation. In most grasshopper species, conflicts between males over females rarely escalate beyond ritualistic displays. Some exceptions include
4012-585: The split between the Caelifera and the Ensifera is no more recent than the Permo-Triassic boundary ; the earliest insects that are certainly Caeliferans are in the extinct families Locustopseidae and Locustavidae from the early Triassic, roughly 250 million years ago. The group diversified during the Triassic and have remained important plant-eaters from that time to now. The first modern families such as
4080-422: 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. A large grasshopper, such as a locust, can jump about a metre (20 body lengths) without using its wings; the acceleration peaks at about 20 g. They jump for several reasons; to escape from a predator, to launch themselves into flight, or simply to move from place to place. For
4148-527: The thorax. Whether winged or not, adult insects can be distinguished by their three-part body plan, with head, thorax, and abdomen; they have three pairs of legs on the thorax. Estimates of the total number of insect species vary considerably, suggesting that there are perhaps some 5.5 million insect species in existence, of which about one million have been described and named. These constitute around half of all eukaryote species, including animals , plants , and fungi . The most diverse insect orders are
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#17327801478004216-446: The tibia bears a double row of spines and there are a pair of articulated spurs near its lower end. The interior of the thorax houses the muscles that control the wings and legs. The abdomen has eleven segments, the first of which is fused to the thorax and contains the tympanal organ and hearing system. Segments two to eight are ring-shaped and joined by flexible membranes. Segments nine to eleven are reduced in size; segment nine bears
4284-480: The tibia is kept flexed by the simultaneous contraction of the flexor tibiae muscle. The extensor muscle is much stronger than the flexor muscle, but the latter is aided by specialisations in the joint that give it a large effective mechanical advantage over the former when the tibia is fully flexed. 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
4352-525: The total of around 22,500 species is probably within 5% of the actual number there; they comment that Canada's list of 30,000 described species is surely over half of the actual total. They add that the 3000 species of the American Arctic must be broadly accurate. In contrast, a large majority of the insect species of the tropics and the southern hemisphere are probably undescribed. Some 30–40,000 species inhabit freshwater ; very few insects, perhaps
4420-445: The upper part of the abdomen pumps the fluid to the head from where it percolates past the tissues and organs on its way back to the abdomen. This system circulates nutrients throughout the body and carries metabolic wastes to be excreted into the gut. 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. Respiration
4488-436: The wing-buds increasing in size at each stage. The number of instars varies between species but is often six. After the final moult, the wings are inflated and become fully functional. The migratory grasshopper, Melanoplus sanguinipes , spends about 25 to 30 days as a nymph, depending on sex and temperature, and lives for about 51 days as an adult. Locusts are the swarming phase of certain species of short-horned grasshoppers in
4556-518: The winter in this state. Diapause is broken by a sufficiently low ground temperature, with development resuming as soon as the ground warms above a certain threshold temperature. The embryos in a pod generally all hatch out within a few minutes of each other. They soon shed their membranes and their exoskeletons harden. These first instar nymphs can then jump away from predators. Grasshoppers undergo incomplete metamorphosis : they repeatedly moult , each instar becoming larger and more like an adult, with
4624-417: The world, but although it infects grasshoppers, the infection is not usually lethal because basking in the sun has the result of raising the insects' temperature above a threshold tolerated by the fungus. 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. This ensures wide dispersal of
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