Portal:Arthropods

The Arthropods Portal

Examples of the five arthropod subphyla

Two fossilised trilobites in a limestone slab.

Trilobitomorpha:
Kainops invius

A large garden spider waits in the centre of its web.

Chelicerata:
Araneus diadematus

A brown centipede with yellow legs and red antennae faces the viewer.

Myriapoda:
Scolopendra cingulata

Hexapoda:
Drosophila melanogaster

Crustacea:
Cancer pagurus

Arthropods (/ˈɑːrθrəpɒd/, from Ancient Greek ἄρθρον (arthron) 'joint', and πούς (pous) 'foot' (gen. ποδός)) are invertebrates in the phylum Arthropoda. They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated (metameric) segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They are an extremely diverse group, with up to 10 million species.

The evolutionary ancestry of arthropods dates back to the Cambrian period. The group is generally regarded as monophyletic, and many analyses support the placement of arthropods with cycloneuralians (or their constituent clades) in a superphylum Ecdysozoa. Overall, however, the basal relationships of animals are not yet well resolved. Likewise, the relationships between various arthropod groups are still actively debated. Today, arthropods contribute to the human food supply both directly as food, and more importantly, indirectly as pollinators of crops. Some species are known to spread severe disease to humans, livestock, and crops. (Full article...)

Selected articles -

Entries here consist of Good and Featured articles, which meet a core set of high editorial standards.

Image 1

The tansy beetle (Chrysolina graminis) is a species of leaf beetle. The common name derives from its main foodplant, Tansy (Tanacetum vulgare), but it can also use other wetland plants such as Gypsywort (Lycopus europaeus) and Water Mint (Mentha aquatica). It measures 7.7–10.5 mm in length and has a characteristic bright metallic green colouration, with pitted elytra and a coppery tinge. In addition to the nominotypical subspecies, which repeats the specific name, C. graminis graminis, there are five further distinct subspecies of Tansy beetle, which, collectively, have a Palearctic distribution, although in the majority of countries where it is found the species is declining. In the United Kingdom it is designated as 'Nationally Rare'. The stronghold population here is located along the banks of the river Ouse in York, North Yorkshire. Other, small, fenland populations exist at Woodwalton Fen and at Welney Wildfowl and Wetlands Trust (WWT) reserve. (Full article...)
Image 2

Female common earwig, Forficula auricularia

Earwigs make up the insect order Dermaptera. With about 2,000 species in 12 families, they are one of the smaller insect orders. Earwigs have characteristic cerci, a pair of forcep-like pincers on their abdomen, and membranous wings folded underneath short, rarely used forewings, hence the scientific order name, "skin wings". Some groups are tiny parasites on mammals and lack the typical pincers. Earwigs are found on all continents except Antarctica.

Earwigs are mostly nocturnal and often hide in small, moist crevices during the day, and are active at night, feeding on a wide variety of insects and plants. Damage to foliage, flowers, and various crops is commonly blamed on earwigs, especially the common earwig Forficula auricularia.

Earwigs have five molts in the year before they become adults. Many earwig species display maternal care, which is uncommon among insects. Female earwigs may care for their eggs; the ones that do will continue to watch over nymphs until their second molt. As the nymphs molt, sexual dimorphism such as differences in pincer shapes begins to show. (Full article...)
Image 3

Female Dichrostigma flavipes

Snakeflies are a group of predatory insects comprising the order Raphidioptera with two extant families: Raphidiidae and Inocelliidae, consisting of roughly 260 species. In the past, the group had a much wider distribution than it does now; snakeflies are found in temperate regions worldwide but are absent from the tropics and the Southern Hemisphere. Recognisable representatives of the group first appeared during the Early Jurassic. They are a relict group, having reached their apex of diversity during the Cretaceous before undergoing substantial decline.

An adult snakefly resembles a lacewing in appearance but has a notably elongated thorax which, together with the mobile head, gives the group their common name. The body is long and slender and the two pairs of long, membranous wings are prominently veined. Females have a large and sturdy ovipositor which is used to deposit eggs in some concealed location. They are holometabolous insects with a four-stage life cycle consisting of eggs, larvae, pupae and adults. In most species, the larvae develop under the bark of trees. They may take several years before they undergo metamorphosis, requiring a period of chilling before pupation takes place. Both adults and larvae are predators of soft-bodied arthropods. (Full article...)
Image 4

Dryomyza anilis

Dryomyza anilis is a common fly from the family Dryomyzidae. The fly is found through various areas in the Northern hemisphere and has brown and orange coloration with distinctive large red eyes. The life span of the fly is not known, but laboratory-reared males can live 28–178 days. D. anilis has recently been placed back in the genus Dryomyza, of which it is the type species. Dryomyzidae were previously part of Sciomyzidae but are now considered a separate family with two subfamilies.

Male D. anilis engage in territorial behavior, guarding carcasses to attract potential mates. Males also guard females, and conflicts over females are frequent. Females typically mate with multiple males. Mating occurs through several rounds of copulation and egg-laying. During mating, males engage in a series of "tapping" rituals where they use their claspers to tap the female's genitals, increasing the chance of them fertilizing the female's eggs. Females lay several batches of eggs on carcasses, fungi, and excrement as well as other substrates. (Full article...)
Image 5

Life cycle of the Polish cochineal in Breyne's Historia naturalis Cocci Radicum... (1731)

Polish cochineal (Porphyrophora polonica, Margarodes polonicus), also known as Polish carmine scales (Polish: czerwiec polski), is a scale insect formerly used to produce a crimson dye of the same name, colloquially known as "Saint John's blood". The larvae of P. polonica are sessile parasites living on the roots of various herbs – especially those of the perennial knawel (Polish: czerwiec trwały) – growing on the sandy soils of Central Europe and other parts of Eurasia. Before the development of aniline, alizarin, and other synthetic dyes, the insect was of great economic importance, although its use was in decline after the introduction of Mexican cochineal to Europe in the 16th century. Historically earlier was used Armenian cochineal scale insect, Porphyrophora hamelii, which is in a same taxonomic family Porphyrophora of the Polish cochineal and in different taxonomic family from cochineal found in the Americas. (Full article...)
Image 6

Polistes exclamans, the Guinea paper wasp, is a social wasp and is part of the family Vespidae of the order Hymenoptera. It is found throughout the United States, Mexico, the Bahamas, Jamaica and parts of Canada. Due to solitary nest founding by queens, P. exclamans has extended its range in the past few decades and now covers the eastern half of the United States, as well as part of the north. This expansion is typically attributed to changing global climate and temperatures. P. exclamans has three specific castes, including males, workers, and queens, but the dominance hierarchy is further distinguished by age. The older the wasp is, the higher it is in ranking within the colony. In most P. exclamans nests, there is one queen who lays all the eggs in the colony. The physiological similarities between the worker and queen castes have led to experiments attempting to distinguish the characteristics of these two castes and how they are determined, though males have easily identifiable physiological characteristics. Since P. exclamans live in relatively small, open combed nests, they are often subject to predators and parasites, such as Chalcoela iphitalis, Elasmus polistis, and birds. P. exclamans have defense and recognition strategies that help protect against these predators and parasites. (Full article...)
Image 7

Potamon fluviatile is a freshwater crab found in or near wooded streams, rivers and lakes in Southern Europe. It is an omnivore with broad ecological tolerances, and adults typically reach 50 mm (2 in) in size during their 10–12 year lifespan. They inhabit burrows and are aggressive, apparently outcompeting native crayfish.

P. fluviatile has been harvested for food since classical antiquity, and is now threatened by overexploitation. Many of the island populations are particularly vulnerable, and the Maltese subspecies has become a conservation icon. A population in Rome may have been brought there before the founding of the Roman Empire. (Full article...)
Image 8

Female (top) & male (bottom)

Chirocephalus diaphanus is a widely distributed European species of fairy shrimp that lives as far north as Great Britain, where it is the only surviving species of fairy shrimp and is protected under the Wildlife and Countryside Act 1981. It is a translucent animal, about 0.5 in (13 mm) long, with reddened tips to the abdomen and appendages. The body comprises a head, a thorax bearing 11 pairs of appendages, and a seven-segmented abdomen. In males, the antennae are enlarged to form "frontal appendages", while females have an egg pouch at the end of the thorax.

The life cycle of C. diaphanus is extremely fast, and the species can only persist in pools without predators. The eggs tolerate drying out, and hatch when re-immersed in water. C. diaphanus was first reported in the scientific literature in 1704, but was only separated from other species and given its scientific name in 1803. The specific epithet diaphanus refers to the animal's transparency. (Full article...)
Image 9

Restoration of P. hamiltoni.

Paleomerus is a genus of strabopid, a group of extinct arthropods. It has been found in deposits from the Cambrian period (Atdabanian epoch). It is classified in the family Strabopidae of the monotypic order Strabopida. It contains two species, P. hamiltoni from Sweden and P. makowskii from Poland. The generic name is composed by the Ancient Greek words παλαιός (palaiós), meaning "ancient", and μέρος (méros), meaning "part" (and therefore, "ancient part").

Paleomerus is one of the oldest arthropods, being sometimes interpreted as the model of the first arachnomorphs. It is part of the order Strabopida, a poorly known group closely related to the aglaspidids of uncertain affinities, often being ignored by researchers and authors due to the poor preservation and abundance of their fossils. It has been suggested that Paleomerus and the closely related Strabops could be synonymous with each other, since they differ only in the size of the telson (the posteriormost division of the body) and the position of the eyes. These two genera were originally deferred by a hypothetical twelfth segment in Paleomerus, but after the discovery and description of a fourth specimen of P. hamiltoni, it has been shown that this segment actually represents the tail of the animal. (Full article...)
Image 10

Fossil of S. acuminata housed at the Senckenberg Museum of Frankfurt

Slimonia is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Slimonia have been discovered in deposits of Silurian age in South America and Europe. Classified as part of the family Slimonidae alongside the related Salteropterus, the genus contains three valid species, S. acuminata from Lesmahagow, Scotland, S. boliviana from Cochabamba, Bolivia and S. dubia from the Pentland Hills of Scotland and one dubious species, S. stylops, from Herefordshire, England. The generic name is derived from and honors Robert Slimon, a fossil collector and surgeon from Lesmahagow.

Out of the four described species of Slimonia, three measured below or up to 20 centimetres (7.9 in) in length. Only S. acuminata was larger, with the largest specimens measuring 100 centimetres (39 in) in length. Though this is large for a predatory arthropod, Slimonia would be exceeded in length by later and more derived (more "advanced") members of the closely related pterygotid family of eurypterids, which would become the largest known arthropods to ever live. (Full article...)
Image 11

Nephrops norvegicus, known variously as the Norway lobster, Dublin Bay prawn, shlobster (shrimp-lobster), langoustine (compare langostino) or scampi, is a slim, coral colored lobster that grows up to 25 cm (10 in) long, and is "the most important commercial crustacean in Europe". It is now the only extant species in the genus Nephrops, after several other species were moved to the closely related genus Metanephrops. It lives in the north-eastern Atlantic Ocean, and parts of the Mediterranean Sea, but is absent from the Baltic Sea and Black Sea. Adults emerge from their burrows at night to feed on worms and fish. (Full article...)
Image 12

Brownimecia clavata holotype

Brownimecia is an extinct genus of ants, the only genus in the tribe Brownimeciini and subfamily Brownimeciinae of the Formicidae. Fossils of the single identified species, Brownimecia clavata, are known from the Middle Cretaceous of North America. The genus is one of several ants described from Middle Cretaceous ambers of New Jersey. Brownimecia was initially placed in the subfamily Ponerinae, until it was transferred to its own subfamily in 2003; it can be distinguished from other ants due to its unusual sickle-like mandibles and other morphological features that makes this ant unique among the Formicidae. The ant is also small, measuring 3.43 millimetres (0.135 in), and a stinger is present in almost all of the specimens collected. The morphology of the mandibles suggest a high level of feeding specialization. (Full article...)
Image 13

Phaeacius lancearius

Phaeacius is a spider genus of the family Salticidae (jumping spiders), found in sub-tropical China and between India and the Malay Peninsula, including Sri Lanka, Sumatra and the Philippines. Although other spiders can jump, salticids including Phaeacius have significantly better vision than other spiders, and their main eyes are more acute in daylight than a cat's and 10 times more acute than a dragonfly's. The main eyes focus accurately on an object at distances from approximately 2 centimetres (0.79 in) to infinity, and in practice can see up to about 75 centimetres (30 in). They do not spin webs.

While most jumping spiders are active hunters, Phaeacius is unusually sedentary, generally resting in its unusual flattened pose for hours or days on logs, tree trunks, pieces of wood or any other solid surface, where it is very well camouflaged. Its preferred prey is moths and other insects, and jumping spiders. Insects can usually move around an inactive Phaeacius, or even over its body, but if the insect moves between the spider's first pair of legs, Phaeacius lunges extremely quickly to bite the prey. Sometimes Phaeacius takes a more active approach, especially if without prey for a week or more. Phaeacius does not enter webs voluntary, and moves away if it touches one accidentally. It can bite through the threads and pull strongly with its legs, but cannot escape from very sticky webs.

The genera Portia and Spartaeus are closely related to Phaeacius. (Full article...)
Image 14

Close up head detail of M. nigrocincta

Myrmecia nigrocincta, commonly known as the jumper ant or jumping jack, is an ant of the genus Myrmecia. The species was first described by Frederick Smith in 1858. Colonies of this ant are abundant in eastern Australia. Ants of this species are known for their ability to jump up to 10 centimetres, and they also have a powerful, venomous sting. Rather than foraging on the ground, M. nigrocincta prefer to forage in trees where they are known to pollinate certain flowers.

This ant is a large species, some workers can grow to over 15 mm (0.6 in) in length. They have a distinctive pattern of orange-red and black which distinguishes them from other Myrmecia species. M. nigrocincta possess the gamergates gene which allows workers to reproduce, either in the presence of a queen or in a colony where the queen is missing. Life expectancy of a worker ant is over one year. They are aggressive when attacking intruders. (Full article...)
Image 15

Fossil of Slimonia acuminata housed at the Senckenberg Museum of Frankfurt

Slimonidae (the name deriving from the type genus Slimonia, which is named in honor of Welsh fossil collector and surgeon Robert Slimon) is a family of eurypterids, an extinct group of aquatic arthropods. Slimonids were members of the superfamily Pterygotioidea and the family most closely related to the derived pterygotid eurypterids, which are famous for their cheliceral claws and great size. Many characteristics of the Slimonidae, such as their flattened and expanded telsons (the posteriormost division of their bodies), support a close relationship between the two groups.

Slimonids are defined as pterygotioid eurypterids with swimming legs similar to those of the type genus, Slimonia, and the second to fifth pair of appendages being non-spiniferous. The family contains only two genera, the almost completely known Slimonia and Salteropterus, which is known only from the telson and the metastoma (a large plate part of the abdomen).

Both slimonid genera preserve flattened and expanded telsons that end in elongated telson spikes. The discovery of several articulated specimens of Slimonia with the tail segments preserved in tight curves, suggesting that the tail segments were considerably more flexible than previously thought and would have been capable of considerable side-to-side movement. Unlike the related pterygotids, the slimonids did not possess robust and powerful cheliceral claws and as such, these telson spikes may have been the primary weaponry used by Slimonia, although this theory is considered unlikely by contemporary researchers. The telson spike of Salteropterus was likely not used as a weapon and was highly distinct and different from that of any other eurypterid. (Full article...)

Did you know ... ?

A hermit crab carrying two large sea anemones on its shell.

Calliactis parasitica (Cnidaria: Actiniaria) and Dardanus calidus (Crustacea: Decapoda)

... that the mutualism between hermit crabs and the sea anemone Calliactis parasitica (pictured) may require the presence of an octopus?
... that Edward L. Kessel assembled the world's most comprehensive collection of Platypezidae flat-footed flies?
... that in the north, the North American paper wasp Polistes annularis has rust-red markings on a predominantly black thorax, but in the south, the thorax is mostly rust-red with black markings?
... that the California Bay pea crab is one of only two marine crustaceans to be included on the IUCN Red List of endangered species?
... that the ground beetle, Lebia grandis, can eat about 23 eggs or three larvae of the Colorado potato beetle every day?
... that the weevil Hylobius transversovittatus has been introduced into the United States and Canada to help control the invasive wetland plant purple loosestrife?

General images -

The following are images from various arthropod-related articles on Wikipedia.

Image 1Holotype of the xiphosuran Lunataspis aurora (from Chelicerata)
Image 2Zoea larva of the European lobster, Homarus gammarus
Image 3The whip spider Phrynichus phipsoni, with short chelicerae and large specialized pedipalps (from Chelicerata)
Image 4Time series photos of a Tibicen Dog Day Cicada moulting in Ohio USA. (from Arthropod exoskeleton)
Image 5The head of an ant: Chitin reinforced with sclerotisation (from Arthropod exoskeleton)
Image 6This Zoea-stage larva is hardly recognisable as a crab, but each time it sheds its cuticle it remodels itself, eventually taking on its final crab form (from Arthropod exoskeleton)
Image 7Arthropleura armata, an arthropleuridean (from Myriapoda)
Image 8The fangs in spiders' chelicerae are so sclerotised as to be greatly hardened and darkened (from Arthropod exoskeleton)
Image 9Tachypodoiulus niger, a millipede (from Myriapoda)
Image 10Eggs of Potamon fluviatile, a freshwater crab
Image 11The house centipede Scutigera coleoptrata has rigid sclerites on each body segment. Supple chitin holds the sclerites together and connects the segments flexibly. Similar chitin connects the joints in the legs. Sclerotised tubular leg segments house the leg muscles, their nerves and attachments, leaving room for the passage of blood to and from the hemocoel (from Arthropod exoskeleton)
Image 12A Eurypauropodid Pauropod. (from Myriapoda)
Image 13Body structure of a typical crustacean – krill (from Crustacean)
Image 14Crab larva barely recognisable as a crab, radically changes its form when it undergoes ecdysis as it matures (from Arthropod exoskeleton)
Image 15Ghost crab, showing a variety of integument types in its exoskeleton, with transparent biomineralization over the eyes, strong biomineralization over the pincers, and tough chitin fabric in the joints and the bristles on the legs (from Arthropod exoskeleton)
Image 16Scolopendra cingulata, a centipede (from Myriapoda)
Image 17A species of Scutigerella, a genus of Symphylan. (from Myriapoda)
Image 18Copepods, from Ernst Haeckel's 1904 work Kunstformen der Natur (from Crustacean)
Image 19
The cuticles of some armoured beetles are rigidly sclerotised
(from Arthropod exoskeleton)
Image 20Decapods, from Ernst Haeckel's 1904 work Kunstformen der Natur (from Crustacean)
Image 21Abludomelita obtusata, an amphipod (from Crustacean)
Image 22In honeypot ant repletes, the abdomens of the workers that hold the sugar solution grow vastly, but only the unsclerotised cuticle can stretch, leaving the unstretched sclerites as dark islands on the clear abdomen (from Arthropod exoskeleton)
Image 23Reconstruction of Mollisonia plenovenatrix, the oldest known arthropod with confirmed chelicerae (from Chelicerata)
Image 24Eryma mandelslohi, a fossil decapod from the Jurassic of Bissingen an der Teck, Germany
Image 25Norway lobsters on sale at a Spanish market
Image 26 This fully-grown robber crab has tough fabric forming its joints, delicate biomineralized cuticle over its sensory antennae, optic-quality over its eyes, and strong, calcite-reinforced chitin armouring its body and legs; its pincers can break into coconuts (from Arthropod exoskeleton)
Image 27Formation of anterior segments across arthropod taxa based on gene expression and neuroanatomical observations, Note the chelicera(Ch) and chelifore(Chf) arose from somite 1 and thus correspond to the first antenna(An/An1) of other arthropods. (from Chelicerata)
Image 28This female Pandinus scorpion Has heavily sclerotised chelae, tail and dorsum, but has flexible lateral areas to allow for expansion when gravid (from Arthropod exoskeleton)
Image 29 Honeybee larvae have flexible but delicate unsclerotised cuticles. (from Arthropod exoskeleton)
Image 30Mature queen of a termite colony, showing how the unsclerotised cuticle stretches between the dark sclerites that failed to stretch as the abdomen grew to accommodate her ovaries (from Arthropod exoskeleton)
Image 31The head of Scutigera coleoptrata, showing antennae, compound eyes and mouthparts (from Myriapoda)
Image 32A shed carapace of a lady crab, part of the hard exoskeleton
Image 33Some of the various hypotheses of myriapod phylogeny. Morphological studies (trees a and b) support a sister grouping of Diplopoda and Pauropoda, while studies of DNA or amino acid similarities suggest a variety of different relationships, including the relationship of Pauropoda and Symphyla in tree c. (from Myriapoda)

Featured picture -

Featured pictures are displayed here, which represent the finest images on English Wikipedia.

Image 1
Danaus genutia
Photograph credit: Charles James Sharp
Danaus genutia, the common tiger or striped tiger, is a species of brush-footed butterfly found in Sri Lanka, India, Myanmar, south-eastern Asia and Australia. It prefers areas of moderate to heavy rainfall, and typical habitats include scrubby jungle, deciduous forests and fallow land near habitations. The insect sequesters toxins from plants, and advertises its unpalatability by having prominent markings and striking colour patterns. This adult male common tiger, of the subspecies D. g. genutia, was photographed in Kerala, India.
Image 2
Sexual dimorphism
Photograph credit: Paolo Costa Baldi
Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics. Differences may include secondary sex characteristics, size, weight, color, or markings, as well as behavioral and cognitive differences. In the butterfly species Colias dimera (also known as the Dimera sulphur), seen here mating in Venezuela, the male on the right is a brighter shade of yellow than the female.
Image 3
Orb-weaver spider
Photo credit: Piccolo Namek
The orb-weaver spiders (family Araneidae) are the familiar builders of spiral wheel-shaped webs often found in gardens, fields and forests. The family is a large one, including over 2800 species in over 160 genera worldwide, making it the third largest known (behind Salticidae and Linyphiidae). The web has always been thought of as an engineering marvel.
Image 4
Simple eye in invertebrates
Photo: JJ Harrison
The head of a female Clynotis severus species of jumping spider. The eyes of a spider are called simple eyes (as opposed to compound eyes) because in each eye, a single lens collects and focuses light onto the retina. In this spider, the two largest eyes in the middle are the most acute. The remainder on the sides and on the top of its head are "secondary eyes".
Image 5
Sympetrum danae
Photograph credit: Charles J. Sharp
Sympetrum danae, the black darter or black meadowhawk, is a species of dragonfly found in northern Europe, Asia, and North America. Both sexes are black and yellow, but the abdomen of the male is largely black while that of the female is largely yellow. Breeding takes place in shallow acidic pools, lake margins and ditches in lowland heaths and moorland bogs. The female lays her eggs during flight by dipping the tip of her abdomen into the water. The eggs hatch the following spring, the larvae developing very rapidly and emerging as adults in as little as two months. The male seen here is perched on a frond of bracken on Warren Heath in Hampshire, England.
Image 6
Attacus taprobanis
Photograph credit: Jeevan Jose
Attacus taprobanis is a species of moth in the family Saturniidae native to southern India and Sri Lanka. This adult male, photographed in Kadavoor, Kerala, developed from a larva feeding on a mahogany tree. When ready to pupate, the larva formed a papery cocoon 7.5 cm (3 in) long interwoven with a leaf; before doing this, the larva had attached the leaf to the stem with a silken thread and cut the leaf stalk. The colours of the dying leaf provided camouflage for the pupa, and the adult insect emerged some 24 days later.
Image 7
Ozyptila praticola
Photo credit: André Karwath
The Ozyptila praticola species of crab spider is found throughout Europe and the Middle East. They do not build webs to trap prey, but are active hunters. Crab spiders are so named because of their first two pairs of legs, which are held out to the side giving them a crab-like appearance. Also, like crabs, these spiders move sideways and backwards more easily than forwards.
Image 8
Roesel's bush-cricket
Photo credit: Richard Bartz
A male Roesel's bush-cricket (Metrioptera roeseli), a European bush-cricket named after August Johann Rösel von Rosenhof, a German entomologist. Its song is very similar to that of Savi's Warbler. Its body length as an adult insect is 15 to 18 mm. It is brown with a pale margin to the sides of the pronotum. Its forewings usually reach midway along its abdomen at rest. However there is a macropterous form of this insect (f. diluta), in which the wings reach beyond the tip of the abdomen. This form appears predominantly during hot summers and enables the species to extend its geographical range rapidly while conditions are suitable; such migrations may also be in response to local overpopulation.
Image 9
Grapsus grapsus
Photograph credit: Diego Delso
The red rock crab (Grapsus grapsus), also known as "Sally Lightfoot", is one of the commonest crabs along the western seaboard of the Americas. John Steinbeck wrote of them, "Everyone who has seen them has been delighted with them ... These little crabs, with brilliant cloisonné carapaces, walk on their tiptoes, they have remarkable eyes and an extremely fast reaction time." He tried to catch them but to little avail. "If you walk slowly, they move slowly ahead of you in droves. If you hurry, they hurry. When you plunge at them, they seem to disappear in a puff of blue smoke."
Image 10
Monarch (butterfly)
Photo credit: Derek Ramsey
The monarch butterfly (Danaus plexippus) is one of the best-known species of butterfly. Its wings feature an easily recognizable orange and black pattern, with a wingspan of 8.9–10.2 centimetres (3½–4 in).
Image 11
Reduviidae
Photo credit: Fir0002
An assassin bug belonging to the Reduviidae family of insects. A predatory insect so named because of its tendency to wait in ambush for its prey, the assassin bug uses its long rostrum to inject a lethal saliva that liquefies the internal structures of the prey, which are then sucked out.
Image 12
Mandible (insect)
Photo credit: Fir0002
The head and mandibles of an Australian bull ant. Insect mandibles grasp, crush, or cut the insect’s food, or defend against predators or rivals. These mandibles move in the horizontal plane unlike those of the vertebrates.
Image 13
Western honey bee
Photograph: Martin Falbisoner
The western honey bee (Apis mellifera) is the most common of the 7–12 species of honey bee worldwide. It is believed to have originated in either Africa or Asia, and spread naturally through Africa, the Middle East and Europe. Following human introduction into the Americas and Oceania, the species is now found on every continent except Antarctica. Humans have been collecting honey from bees for thousands of years, with evidence in the form of rock art found in France and Spain, dating to around 7000 BC. Along with other insects, the honey bee is an important pollinator, with a large number of the crop species farmed worldwide depending on it.
Image 14
Scorpius
Lithograph: Sidney Hall; restoration: Adam Cuerden
A lithograph by Sidney Hall, published in Urania's Mirror, depicting the constellation Scorpius. One of the 48 constellations identified by the Greek astronomer Ptolemy in the second century, Scorpius lies between Libra to the west and Sagittarius to the east. It contains 18 main stars, the brightest of which is Antares. Although frequently identified as a scorpion, this constellation has also been likened to a "leaning coconut tree" (Java) or "Maui's fishhook" (Hawaii).
Image 15
Pieris brassicae
Photo credit: Didier Descouens
Caterpillar of Large white butterfly. Pieris brassicae is a butterfly in the family Pieridae. It is a close relative of the small white, Pieris rapae. The large white is common throughout Europe, North Africa and Asia.
Image 16
Leptosia nina
Photograph credit: Jeevan Jose
Leptosia nina, known as the psyche, is a species of butterfly in the family Pieridae (the sulphurs, yellows and whites), found in the Indian subcontinent, southeastern Asia, and Australia. It has a small wingspan of 2.5 to 5 cm (1 to 2 in). The upper side of the otherwise white forewing has a large, somewhat pear-shaped, black spot; this spot is also present on the underside which is scattered with greenish dots and speckles, sometimes arranged in bands. This L. nina butterfly was photographed in Kerala, India.
Image 17
Mictyris longicarpus
Photo credit: liquidGhoul
The light blue soldier crab (Mictyris longicarpus) inhabits beaches in the Indo-Pacific region. Soldier crabs filter sand or mud for microorganisms. They congregate during the low tide, and bury themselves in a corkscrew pattern during high tide, or whenever they are threatened.
Image 18
Buffalo treehopper
Credit: Quartl
The buffalo treehopper, Stictocephala bisonia (formerly Ceresa bisonia), is a species of treehopper native to North America. They use their piercing mouthparts to feed on the sap of plants including black locust, clover, elm, goldenrod and willow.
Image 19
Longhorn beetle
Credit: KarlR
Longhorn beetles (Saperda carcharias pictured) are a cosmopolitan family of beetles, Cerambycidae, characterised by extremely long antennae. It is a large family, with over 20,000 described species; several are serious pests, with the larvae boring into wood.
Image 20
Papilio polymnestor
Photograph credit: Jeevan Jose
Papilio polymnestor, the blue Mormon, is a species of swallowtail butterfly found in southern India and Sri Lanka. It is a woodland species, often seen on forest paths and near streams. The larvae feed on trees in the family Rutaceae, such as citrus. Young larvae are green with white markings and position themselves on the upper surface of leaves, relying on their cryptic colouring, which resembles bird droppings, for protection. Older larvae seek less conspicuous locations, and have a unique habit of securing their balance by weaving silk on the substratum. This adult male P. polymnestor butterfly was photographed in the Indian state of Kerala.
Image 21
Pollination
Photo credit: Jon Sullivan
A honey bee extracts nectar from a flower using its proboscis. Tiny hairs covering the bee's body maintain a slight electrostatic charge, causing pollen from the flower's anthers to stick to the bee's hairs, allowing for pollination when the bee moves on to another flower.
Image 22
Atlantic horseshoe crab
Credit: Didier Descouens
The Atlantic horseshoe crab, Limulus polyphemus, is a marine chelicerate arthropod. It is most commonly found in the Gulf of Mexico and along the northern Atlantic coast of North America, with Delaware Bay a main area of annual migration.
Image 23
Xylotrupes socrates
Photo credit: Basile Morin
Xylotrupes socrates (Siamese rhinoceros beetle, or "fighting beetle"), male, on a banana leaf. This scarab beetle is particularly known for its role in insect fighting in Northern Laos and Thailand.
Image 24
Mantis shrimp
Credit: Jens Petersen
Mantis shrimp (peacock mantis shrimp – Odontodactylus scyllarus – pictured) are marine crustaceans of the order Stomatopoda. They take their name from the physical resemblance to praying mantises and shrimp.

Taxa

Chelicerata: spider · Acari · Opiliones · pseudoscorpion · scorpion · Solifugae · sea spider · Schizomida · Amblypygi · Thelyphonida · Palpigradi · Ricinulei · Xiphosura · †Chasmataspidida · †Eurypterida
Crustacea: Malacostraca (Decapoda – crab, lobster, hermit crab; Amphipoda; Isopoda; mantis shrimp) · Maxillopoda (barnacle; copepod) · Branchiopoda (fairy shrimp; Triops; Daphnia) · ostracod · Remipedia · Cephalocarida
Hexapoda: Entognatha (springtail; Diplura; Protura) · insect (beetle; fly; bee; wasp; ant; butterfly; moth; cockroach; flea; louse; mayfly; dragonfly; damselfly; earwig; mantis)
Myriapoda: centipede · millipede (pill millipede) · Pauropoda · Symphyla · †Arthropleuridea
†Trilobite: †Agnostida · †Asaphida · †Corynexochida · †Harpetida · †Nectaspida · †Redlichiida · †Lichida · †Phacopida · †Proetida · †Ptychopariida

† indicates an extinct taxon.

Topics

Anatomy: antenna · arthropod exoskeleton · arthropod leg · arthropod eye · book lung · chelicerae · differences between butterflies and moths · gill · insect morphology · invertebrate trachea · Malpighian tubule system · mandible · rostrum · simple eye in invertebrates

Study: arachnology · entomology · forensic entomology · glossary of entomology terms · lepidopterist · list of carcinologists · list of entomologists · myrmecology · timeline of entomology

Development: crustacean larvae · ecdysis · exuvia

As food: entomophagy · fried spider · crab fisheries · lobster fishing · shrimp paste

Miscellaneous: arthropod bites and stings · beneficial insects · economic entomology · endangered arthropod · evolution of insects · insectivore

Related portals

Recognized content

Featured articles

Featured lists

Good articles

Featured images

Featured image set: butterfly wing magnifications

Full list of featured images

File:Abantiades Laptipennis.jpg
File:Acrididae grasshopper-2.jpg
File:Adult citrus root weevil, Diaprepes abbreviatus.jpg
File:Aedes aegypti.jpg
File:Aeshna cyanea freshly slipped L2.jpg
File:American Bird Grasshopper.jpg
File:Ampulex compressa.jpg
File:Anthomyiidae sp. 1 (aka).jpg
File:Anthomyiidae sp.jpg
File:Ants eating cicada, jjron 22.11.2009.jpg
File:Apis mellifera carnica worker hive entrance 3.jpg
File:Apis mellifera flying.jpg
File:Arachnis picta edit1.jpg
File:Araneus heroine.jpg
File:Arctiidae caterpillar edit.jpg
File:Argiope sp.jpg
File:Assassin bug aug08 02.jpg
File:Aus soldier Crab.jpg
File:Australian painted lady feeding.jpg
File:Austroaeschna tasmanica 2.jpg
File:Austroagrion watsoni.jpg
File:Austroicetes frater.jpg
File:Austroicetes vulgaris.jpg
File:Austrolestes analis.jpg
File:Austrolestes annulosus.jpg
File:Austrolestes cingulatus male.jpg
File:Austrolestes cingulatus03.jpg
File:Battus philenor 02.jpg
File:Beautiful Demoiselle Calopteryx virgo.jpg
File:Bee March 2008-10.jpg
File:bee_pollenating_a_rose.jpg
File:Bees Collecting Pollen 2004-08-14.jpg
File:Beetle-Bessbug.jpg
File:Bembix sp.jpg
File:Bengalia sp.jpg
File:Black soldier flies mating.jpg
File:Brachypelma edit.jpg
File:Brahmaea wallichii insulata (Brahmeid Moth) wb edit.jpg
File:Bullant head detail.jpg
File:Bumblebee October 2007-3a.jpg
File:Butterfly April 2008-2a.jpg
File:Butterfly August 2008-3.jpg
File:Butterfly vindula arsinoe.jpg
File:Cairns birdwing - melbourne zoo.jpg
File:Caliphrodae_head.jpg
File:Calliphora augur whitebackground.jpg
File:Calliphora sp Portrait.jpg
File:Calliphora vomitoria edit.jpg
File:Calliphora vomitoria Portrait.jpg
File:Calocoris affinis.jpg
File:Calopteryx virgo male.jpg
File:Camponotus sp. ant.jpg
File:Carpilius convexus is consuming Heterocentrotus trigonarius in Hawaii.jpg
File:Cercophonius squama.jpg
File:Ceriagrion glabrum female.jpg
File:Ceriagrion glabrum male panorama.jpg
File:Cethosia cyane.jpg
File:Cetonia-aurata.jpg
File:CH Caterpillar.jpg
File:Ch.megacephala wiki.jpg
File:Chalcostephia flavifrons.jpg
File:Charaxes brutus natalensis.jpg
File:Chrysomya albiceps eating.jpg
File:Chrysopa sp. AF 1.jpg
File:Chrysopilus Snipe fly.jpg
File:Chthamalus stellatus.jpg
File:Cicada molting animated-2.gif
File:Citrus Swallowtail Papilio demodocus.jpg
File:Clerid beetle04.jpg
File:Coenagrionidae2.jpg
File:Common brown robberflies mating.jpg
File:Common brown robberfly with prey.jpg
File:Common Eggfly02 - melbourne zoo.jpg
File:Common grass blue.jpg
File:Common jassid nymph and ant02.jpg
File:Coryphistes ruricola.jpg
File:Craticulina sp.jpg
File:Culex pipiens diagram en.svg
File:Culex restuans larva diagram en.svg
File:Culex sp larvae.png
File:Culex sp..jpg
File:Damselfly October 2007 Osaka Japan.jpg
File:Danaid Eggfly Hypolimnas misippus.jpg
File:Dark Small-branded Swift.jpg
File:Darkling beetle.jpg
File:Darter August 2007-22 edit.jpg
File:Dirce Beauty Colobura dirce.jpg
File:Dolichomitus imperator Oviposition R Bartz.jpg
File:Dragonfly compound eyes02.jpg
File:Dragonfly macro.jpg
File:Dragonfly morphology edit 3.svg
File:Drohnenpuppen 79d.jpg
File:Drone flies mating.jpg
File:Drone fly feeding on marigold.jpg
File:Dungeness crab face closeup.jpg
File:Emerus feae.jpg
File:Emperor Gum Moth.jpg
File:Empis livida (aka).jpg
File:Enallagma cyathigerum 1(loz).jpg
File:Eriphia verrucosa male 2009 G5.jpg
File:Eristalinus fuscicornis.jpg
File:Eristalinus megacephalus.jpg
File:Eristalinus October 2007-6.jpg
File:Eryphanis_sp.jpg
File:European wasp white bg.jpg
File:Eusthenia sp.jpg
File:Evania appendigaster.jpg
File:Face of a Southern Yellowjacket Queen (Vespula squamosa).jpg
File:Female Tetraloniella sp edit1.jpg
File:Fiddler beetle nov07.jpg
File:Flesh fly concentrating food.jpg
File:Flower spider with moth02.jpg
File:FlyingBugPollinating-Oct15-lighter-cleaner.jpg
File:Garden orb weaver05.jpg
File:Gminatus australis with Beetle.jpg
File:Golden stag beetle.jpg
File:Graphium caterpillar.jpg
File:Graphium macleayanus.jpg
File:Graphomya eustolia crop.jpg
File:Grapsus grapsus Galapagos Islands.jpg
File:Green Grass-Dart.jpg
File:Green tent spider.jpg
File:Grosser Wollschweber Bombylius major detail edit.jpg
File:Haeckel Arachnida.jpg
File:Heliconius erato Richard Bartz.jpg
File:Heliconius melpomene 2b Richard Bartz.jpg
File:Hermetia illucens Black soldier fly edit1.jpg
File:Holoplatys semiplanata with scale02.jpg
File:Homoneura sp wb2.jpg
File:Homoneura sp02.jpg
File:Honeybee landing on milkthistle02.jpg
File:HookeFlea01.jpg
File:Horehound Bug apr07 edit.jpg
File:Hornet-vespa.jpg
File:Housefly mating.jpg
File:Housefly on a leaf crop.jpg
File:Hoverflies mating midair.jpg
File:Hoverfly December 2007-8.jpg
File:Hoverfly January 2008-6.jpg
File:Hoverfly07.jpg
File:IC Macroglossum stellatarum1 NR.jpg
File:Ichneumonidae mating.jpg
File:Idea leuconoe Weiße Baumnymphe crop.jpg
File:Inachis io top detail MichaD.jpg
File:Inachis io top MichaD.jpg
File:Inachis_io_Lill-Jansskogen.JPG
File:Ischnura heterosticta02.jpg
File:Ixodus ricinus 5x.jpg
File:Jalmenus-evagoras-ventral.jpg
File:Joined moths.JPG
File:Jumping spider with prey.jpg
File:Junonia villida 2.jpg
File:Junonia villida tas.jpg
File:Large brown mantid close up nohair.jpg
File:Large brown mantid07 edit.jpg
File:Lime Butterfly Papilio demoleus.jpg
File:Long legged fly.jpg
File:Long nosed weevil edit.jpg
File:Long tongue tachinid fly edit.jpg
File:Longhorn beetle Cerambycinae.jpg
File:Lophyra sp Tiger beetle edit1.jpg
File:Lubber.jpg
File:Lycosidae female carrying young.jpg
File:Macrotona australis laying eggs.jpg
File:Macroxiphus sp cricket.jpg
File:Male yellow flower wasp02.jpg
File:Marbled Orb Weaver.jpg
File:Meat eater ant qeen excavating hole.jpg
File:Metrioptera roeseli male Richard Bartz.jpg
File:Metriorrhynchus rhipidius02.jpg
File:Microphoto-butterflywing.jpg
File:Miomantis paykullii Luc Viatour.jpg
File:Mole cricket02.jpg
File:Monarch Butterfly Danaus plexippus on Echinacea purpurea 2800px.jpg
File:Monarch Butterfly Danaus plexippus on Milkweed Hybrid 2800px.jpg
File:Monarch Butterfly Danaus plexippus Tagged Closeup 3008px.jpg
File:Mosquito Tasmania crop.jpg
File:Mouse spider.jpg
File:Musca domestica Portrait.jpg
File:Myrmecia forficata.jpg
File:Oncometopia orbona Kaldari.jpg
File:Orb weaver black bckgrnd03 crop.jpg
File:Orthetrum chrysostigma.jpg
File:Oxya yezoensis November 2007 Osaka Japan Edit2.jpg
File:Ozyptila praticola - front (aka).jpg
File:P1160778 Melitaea athalia.jpg
File:Pachygrapsus_marmoratus_2008_G1.jpg
File:Pachygrapsus_marmoratus_2009_G4.jpg
File:Panorpa communis 2 Luc Viatour.jpg
File:Paralucia aurifer.jpg
File:Pasture day moth caterpillar02.jpg
File:Peablue October 2007 Osaka Japan.jpg
File:Peacock mite, Tuckerella sp.jpg
File:Pegesimallus sp robberfly.jpg
File:Pelopidas sp.jpg
File:Perga sp. AF 2 edit1.jpg
File:Periclimenes imperator (Emperor shrimp) on Bohadschia argus (Sea cucumber).jpg
File:Phaneroptera sp.jpg
File:Phaon iridipennis.jpg
File:Philaethria hecale 2 Richard Bartz.jpg
File:Pieris sp 3.jpg
File:Pisaura mirabilis on Plantago lanceolata.jpg
File:Plectroctena sp ants.jpg
File:Polistes sp wasp.jpg
File:Praying_mantis_india.jpg
File:Pseudalmenus chlorinda.jpg
File:Pseudatelus sp..jpg
File:Punctate Flower Chafer.jpg
File:Redeye cicada02.jpg
File:Rhithrogena_germanica_subimago_on_Equisetum_hyemale.jpg
File:Robal.png
File:Rust Mite, Aceria anthocoptes.jpg
File:Salticidae sp. AF.jpg
File:Salticidae_sp._AF_2.jpg
File:Sand wasp feeding edit1.jpg
File:Sarcophaga Bercaea2.jpg
File:Sarcophaga ruficornis fleshfly mating.jpg
File:Sarcophaga_nodosa.jpg
File:Sawfly larvae - Pergidae sp.jpg
File:Sceliodes cordalis.jpg
File:Sceliphron spirifex TZ edit1.jpg
File:Scheme ant worker anatomy-en.svg
File:Schnepfenfliege Rhagio scolopaceus2.jpg
File:Schwarze Habichtsfliege Dioctria atricapilla.jpg
File:SEM image of a Peacock wing, slant view 1.JPG
File:SEM image of a Peacock wing, slant view 2.JPG
File:SEM image of a Peacock wing, slant view 3.JPG
File:SEM image of a Peacock wing, slant view 4.JPG
File:Sibylla pretiosa Cryptic mantis Luc Viatour.jpg
File:Skorpionsfliege Panorpa communis male full.jpg
File:Soldierfly.jpg
File:Sphegina montana Syrphidae.jpg
File:Spider and bee June 2008-1.jpg
File:Spider_internal_anatomy-en.svg
File:Squash bug Coreidae hz.jpg
File:Squilla mantis (l'Ametlla) brighter and quality.jpg
File:Stomoxys calcitrans on aloe vera.jpg
File:Sympetrum flaveolum - side (aka).jpg
File:Syrphidae poster.jpg
File:Tachina fly Gonia capitata feeding honey.jpg
File:Tachinidae.jpg
File:Tachysphex specie edit1.jpg
File:Tau Emerald inflight edit.jpg
File:Thiodina puerpera female 02.jpg
File:Thomas Bresson - Machaon-1 (by) edit.jpg
File:Tobacco Hornworm 1.jpg
File:Traumatic insemination 1 edit1.jpg
File:Trithemis annulata.jpg
File:Trithemis kirbyi.jpg
File:Triops-longicaudatus-dorsal-ventral-edit2.jpg
File:Two-lined gum treehopper03.jpg
File:Ulysses Butterfly - melbourne zoo.jpg
File:Vanessa January 2008-2.jpg
File:Varroa destructor on honeybee host.jpg
File:Vespa crabro germana with prey Richard Bartz Crop.jpg
File:Wandering glider horizontal edit1.jpg
File:Wasp August 2007-12.jpg
File:Wasp colony.jpg
File:Wasp July 2008-1.jpg
File:Wasp March 2008-1.jpg
File:Wasp May 2008-11.jpg
File:Wasp mimicking hoverfly.jpg
File:Wasp morphology.png
File:Weevil September 2008-1.jpg
File:Western tent caterpillars Malacosoma californicum in Joshua Tree NP.jpg
File:Yellow mite (Tydeidae) Lorryia formosa 2 edit.jpg
File:Yellow mite (Tydeidae), Lorryia formosa.jpg
File:Yellow striped hunter mating.jpg
File:Young grasshopper on grass stalk02.jpg
File:Zizina labradus-Butterfly-on-Rose SC,-EG-Vic,-23.2.2008.jpg

WikiProjects

WikiProject Tree of Life
- WikiProject Animals
  - WikiProject Arthropods
    - WikiProject Spiders
    - WikiProject Insects
      - WikiProject Lepidoptera

What are WikiProjects?

To do

Here are some tasks you can do:

Start a new article. Arthropods cover an huge range of taxa and other topics, so there will always be plenty of missing articles. Some which have been explicitly requested are listed here.
Clean up existing articles. Lists of articles needing cleanup are available either grouped by the work needed or ungrouped.
Expand an existing article. Existing articles are often incomplete and missing information on key aspects of the topic. It is particularly important that the most widely read articles be broad in their scope. Wikipedia:WikiProject Arthropods/Popular pages (updated monthly) shows the number of views each article gets, along with assessments of its quality and importance. Articles with higher importance ratings and greater numbers of views are the priority for article improvements, but almost all our articles would benefit from expansion. Stubs can be found in Category:Arthropod stubs and its subcategories.

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

Commons
Free media repository
Wikibooks
Free textbooks and manuals
Wikidata
Free knowledge base
Wikinews
Free-content news
Wikiquote
Collection of quotations
Wikisource
Free-content library
Wikispecies
Directory of species
Wikiversity
Free learning tools
Wikivoyage
Free travel guide
Wiktionary
Dictionary and thesaurus

Discover Wikipedia using portals

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.