Portal:Arthropods/Selected article
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Selected article 1
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Cochineal is the name of both a crimson or carmine dye and of the cochineal insect (Dactylopius coccus), a scale insect in the suborder Sternorrhyncha, from which the dye is derived. There are other species in the genus Dactylopius which can be used to produce cochineal extract, but they are difficult to distinguish from D. coccus. The primary biological distinctions between species are minor differences in host plant preferences, in addition to very different geographic distributions. D. coccus itself is native to tropical and subtropical South America and Mexico.
This type of insect, a primarily sessile parasite, lives on cacti from the genus Opuntia, feeding on moisture and nutrients in the cacti. The insect produces carminic acid which deters predation by other insects. Carminic acid can be extracted from the insect's body and eggs to make the dye. Cochineal is primarily used as a food colouring and for cosmetics. (Full article...)
Selected article 2
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The effects suffered by bees from toxic chemicals that they encounter in the environment can be severe. These chemicals include various man-made compounds, such as insecticides and fertilizers, as well as a variety of naturally-occurring chemicals from plants, such as ethanol resulting from the fermentation of organic material. Intoxication in bees can result from exposure to ethanol from fermented nectar, ripe fruits, and man-made and natural chemicals in the environment.
The effects of alcohol on bees are sufficiently similar to the effects of alcohol on humans that honey bees have been used as models of human ethanol intoxication. However, the metabolism of bees and humans is sufficiently different that bees can safely collect nectar from plants that contain compounds toxic to humans. The honey produced by bees from these toxic nectars can be poisonous if consumed by humans. Many humans have eaten toxic honey and become quite ill as a result. Natural processes can also introduce toxic substances into nontoxic honey produced from nontoxic nectar. Microorganisms in honey can convert some of the sugars in honey to the toxic compound ethanol. This process of ethanol fermentation is intentionally harnessed to produce the alcoholic beverage mead from fermented honey. (Full article...)
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Ants (Iridomyrmex purpureus pictured) are eusocial insects of the family Formicidae and, along with the related families of wasps and bees, belong to the order Hymenoptera. They are a diverse group of more than 12,000 species in around 160 genera, with a higher diversity in the tropics. They are known for their highly organised colonies and nests, which sometimes consist of millions of individuals. Individuals are divided into sub-fertile, and more commonly sterile, females ("workers", "soldiers", and other castes), fertile males ("drones"), and fertile females ("queens"). Colonies can occupy and use a wide area of land to support themselves. Ant colonies are sometimes described as superorganisms because the colony appears to operate as a unified entity.
Ants have colonised almost every landmass on Earth. The only places lacking indigenous ant species are Antarctica, Greenland, Iceland, parts of Polynesia, the Hawaiian Islands, and other remote or inhospitable islands. When all their individual contributions are added up, they may constitute up to 15% to 25% of the total terrestrial animal biomass. (Full article...)
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Crustaceans are a large group of arthropods, comprising approximately 52,000 described species, and are usually treated as the subphylum Crustacea. They include various familiar animals, such as lobsters, crabs, shrimp, crayfish and barnacles. The majority are aquatic, living in either fresh water or marine environments, but a few groups have adapted to terrestrial life, such as land crabs, terrestrial hermit crabs and woodlice. Most crustaceans are motile, moving about independently, although a few taxa are parasitic and live attached to their hosts (including sea lice, fish lice, whale lice, tongue worms, and Cymothoa exigua, all of which may be referred to as "crustacean lice"), and adult barnacles live a sessile life – they are attached head-first to the substrate and cannot move independently.
The scientific study of crustaceans is known as carcinology. Other names for carcinology are malacostracology, crustaceology and crustalogy, and a scientist who works in carcinology is a carcinologist, crustaceologist or crustalogist. (Full article...)
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The Cape lobster, Homarinus capensis, is a species of small lobster that lives off the coast of South Africa, from Dassen Island to Haga Haga. Only a few dozen specimens are known, mostly regurgitated by reef-dwelling fish. It lives in rocky reefs, and is thought to lay large eggs that have a short larval phase, or that hatch directly as a juvenile. The species grows to a total length of 10 cm (3.9 in), and resembles a small European or American lobster; it was previously included in the same genus, Homarus, although it is not very closely related to those species, and is now considered to form a separate, monotypic genus – Homarinus. Its closest relatives are the genera Thymops and Thymopides. (Full article...)
Selected article 6
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The Madagascan sunset moth or simply sunset moth, Chrysiridia rhipheus, is a day-flying moth of the Uraniidae family. It is considered to be one of the most impressive and beautiful Lepidoptera. Famous worldwide, it is featured in most coffee table books on the Lepidoptera and is much sought after by collectors. It is very colourful, though the iridescent parts of the wings do not have pigment; rather the colours originate from optical interference. Adult moths have a wingspan of 7–9 centimetres (2.8–3.5 in).
The moth was considered to be a butterfly by Dru Drury, who described it in 1773 and placed it in the genus Papilio. Jacob Hübner placed it in the moth genus Chrysiridia in 1823. Later redescriptions led to junior synonyms such as Chrysiridia madagascariensis (Lesson, 1831). At first the moth was thought to be from China or Bengal, but was later found to be endemic to Madagascar. It is found throughout the year in most parts of the island, with peak populations between March and August, and smallest numbers between October and December. (Full article...)
Selected article 7
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Abantiades latipennis, known as the Pindi moth, is a species of moth in the Hepialidae family. Endemic to Australia and identified in 1932, it is most populous in temperate rainforest where eucalypts are prevalent, as the larvae feed primarily on their roots. Females lay eggs during flight in a scattering fashion. The larvae live for over eighteen months underground, while adult moths survive for approximately one week, as they have no mouthparts with which to feed. The moths are preyed upon by a number of predators, including bats and owls. Brown in colour overall, males are paler and the identifying silver bars of the male's wings are more prominent than those of the females, with dark margins. Male adults are generally smaller.
Established clearfelling practices have been shown to favour the Pindi moth, and could lead to it being considered a pest due to opportunistic proliferation of the species. The resulting damage caused to the trees on which it feeds may be considered significant. (Full article...)
Selected article 8
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The California spiny lobster, Panulirus interruptus, is a species of spiny lobster found in the eastern Pacific Ocean from Monterey Bay, California to the Gulf of Tehuantepec, Mexico. It typically grows to a length of 30 cm (12 in) and is a reddish-brown color with stripes along the legs, and has a pair of enlarged antennae but no claws. The interrupted grooves across the tail are characteristic for the species.
Females can carry up to 680,000 eggs, which hatch after 10 weeks into flat phyllosoma larvae. These feed on plankton before the metamorphosis into the juvenile state. Adults are nocturnal and migratory, living among rocks at depths of up to 65 m (213 ft), and feeding on sea urchins, clams, mussels and worms. The spiny lobster is eaten by various fish, octopuses and sea otters, but can defend itself with a loud noise produced by its antennae. The California spiny lobster is the subject of both commercial and recreational fishery in both Mexico and the United States, with sport fishermen using hoop nets and commercial fishermen using lobster traps. (Full article...)
Selected article 9
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Cancer pagurus, commonly known as the edible crab or brown crab, is a species of crab found in the North Sea, North Atlantic Ocean and perhaps in the Mediterranean Sea. It is a robust crab of a reddish-brown colour, having an oval carapace with a characteristic "pie crust" edge and black tips to the claws. A mature adult may have a carapace width of up to 25 cm (10 in) and weigh up to 3 kg (6.6 lb). C. pagurus is a nocturnal predator, targeting a range of molluscs and crustaceans. It is the subject of the largest crab fishery in Western Europe, centred around the coasts of the British Isles, with more than 60,000 tonnes caught annually. Around one third of the weight of an adult edible crab is meat, of which one third is white meat from the claws, and two thirds is brown meat from the body. (Full article...)
Selected article 10
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Carcinus maenas is a common littoral crab, and an important invasive species, listed among the 100 "world's worst alien invasive species". Although native to the Baltic Sea, North Sea and north-east Atlantic Ocean, it has since become established on both east and west coasts of North America, in Argentina, South Africa and Australia. C. maenas is a predator feeding on many organisms, particularly bivalve molluscs (such as clams, oysters, and mussels), polychaetes and small crustaceans. It is primarily nocturnal, although activity also depends on the tide, and crabs can be active at any time of day. C. maenas is known by different names around the world. In the British Isles, it is generally referred to simply as the shore crab. In North America and South Africa, it bears the name green crab or European green crab. In Australia and New Zealand, it is referred to as either the European green crab or European shore crab. (Full article...)
Selected article 11
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Throughout history, there have been many depictions of spiders in popular culture, mythology and symbolism. From Greek mythology to African folklore, the spider has been used in human culture to represent many varied things and indeed endures on into the present day with characters such as Shelob from The Lord of the Rings and Spider-Man from the eponymous comic series. The spider has symbolised patience due to its hunting technique of setting webs and waiting for prey, as well as mischief and malice for its poison and the slow death it causes, its venom often seen as a curse.
Although not all spiders spin webs to hunt prey, they have been attributed by numerous cultures with the origination of basket-weaving, knotwork, weaving, spinning and net making. Web-spinning also caused the association of the spider with creation myths as they seem to have the ability to excrete their own artistic worlds. Spiders have been the focus of fears, stories and mythologies of various cultures for centuries. (Full article...)
Selected article 12
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Earwigs make up the insect order Dermaptera, found throughout the Americas, Eurasia and Australia. It is one of the smaller insect orders, with only 1,800 recorded species in 12 families. Typical earwigs have characteristic cerci, a pair of forceps-like pincers on their abdomen, and membranous wings folded underneath short forewings, hence the scientific name for the order, which translates literally as "skin wings". Some groups within the earwig order are tiny parasites on mammals and lack the typical pincers. Earwigs rarely fly, even though they are capable of flight.
Earwigs are nocturnal; they 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 are commonly blamed on earwigs, especially the common earwig Forficula auricularia. Earwigs undergo an average of 5 moults over the course of a year, their average life expectancy, before they become adults. Many earwig species display maternal care, which is uncommon among insects. (Full article...)
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Homarus gammarus, known as the European lobster or common lobster, is a species of clawed lobster from the eastern Atlantic Ocean, Mediterranean Sea and parts of the Black Sea. It is closely related to the American lobster, H. americanus. It may grow to a length of 60 cm (24 in) and a mass of 6 kilograms (13 lb), and bears a conspicuous pair of claws. In life, the lobsters are blue, only becoming "lobster red" on cooking. Mating occurs in the summer, producing eggs which are carried by the females for up to a year before hatching into planktonic larvae. Homarus gammarus is a highly esteemed food, and is widely caught using lobster pots, mostly around the British Isles.
Attempts have been made to introduce H. gammarus to New Zealand, alongside other European species such as the edible crab, Cancer pagurus. Between 1904 and 1914, one million lobster larvae were released from hatcheries in Dunedin, but the species did not become established there. (Full article...)
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Insects (from Latin insectum, a calque of Greek ἔντομον [éntomon], "cut into sections") are a class within the arthropods that have a chitinous exoskeleton, a three-part body (head, thorax, and abdomen), three pairs of jointed legs, compound eyes, and two antennae. They are among the most diverse group of animals on the planet and include more than a million described species and represent more than half of all known living organisms. The number of extant species is estimated at between six and ten million, and potentially represent over 90% of the differing metazoan life forms on Earth.
Insects typically move about by walking, flying or occasionally swimming. Because it allows for rapid yet stable movement, many insects adopt a tripedal gait in which they walk with their legs touching the ground in alternating triangles. Insects are the only invertebrates to have evolved flight. Many insects spend at least part of their life underwater, with larval adaptations that include gills and some adult insects are aquatic and have adaptations for swimming. Some species, like water striders, are capable of walking on the surface of water. (Full article...)
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The katipo, Latrodectus katipo, is an endangered species of spider native to New Zealand. A member of the genus Latrodectus, it is related to the Australian redback spider, and the North American black widow spiders. The species is venomous to humans, capable of delivering a dangerous spider bite. Katipo is a Māori name and means "night-stinger". It is a small to medium-sized spider with the female having a distinctive black body with a white bordered red stripe on its back. North of 39° 15' S females do not have a red stripe and are all black. The male is much smaller than the female and quite different in appearance, being white with black stripes and red diamond shaped markings. Katipo have a narrow habitat, being only found living in sand dunes close to the seashore. They range throughout most of coastal New Zealand, but are not found at the southernmost regions. Spinning an irregular tangled web amongst dune plants or other debris, they feed mainly on ground dwelling insects. (Full article...)
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The Lulworth Skipper, Thymelicus acteon, is a butterfly of the Hesperiidae family. Its name is derived from Lulworth Cove in the county of Dorset, where the first specimens in Great Britain were collected in 1832 by English naturalist James Charles Dale.
The species occurs locally across Central Europe, Asia Minor and North Africa, where its population is considered stable. Its numbers have declined in Northern Europe, leading to its European status of 'vulnerable'. Its range in Britain is restricted to the south coast of Dorset, however it is locally abundant and its numbers currently are perhaps at their greatest since its discovery there.
With a wingspan of 24–28 millimetres (0.9–1.1 in), females being larger than males, the Lulworth Skipper is a small butterfly, the smallest member of the Thymelicus genus in Europe and among the smallest butterflies in Britain. Aside from the size difference, the sexes are distinguished by females having a distinct circle of golden marks on each forewing. Due to their likeness to the rays around the eye of a peacock's feather, these are often known as 'sun-ray' markings, and they can faintly appear on males. (Full article...)
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Scyllarides latus, the Mediterranean slipper lobster, is a species of slipper lobster found in the Mediterranean Sea and in the eastern Atlantic Ocean. It is edible and highly regarded as food, but is now rare over much of its range due to overfishing. S. latus can grow to a total body length about 45 centimetres (18 in), although rarely more than 30 cm (12 in). An individual may weigh as much as 1.5 kilograms (3.3 lb). As in all slipper lobsters, the second pair of antennae are enlarged and flattened into "shovels" or "flippers". They have no claws, and rely on camouflaged and their tough exoskeleton for protection. They are nocturnal, emerging from caves and other shelters during the night to feed on molluscs.
As well as being eaten by humans, S. latus is also preyed upon by a variety of bony fish. Its closest relative is S. herklotsii, which occurs off the Atlantic coast of West Africa; other species of Scyllarides occur in the western Atlantic Ocean and the Indo-Pacific. The larvae and young animals are largely unknown. (Full article...)
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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 is the only population of freshwater crabs to occur in the middle of a large city, and may have been brought there before the founding of the Roman Empire.
Potamon fluviatile has a generalist diet, feeding on vegetable debris, scraping algae from surfaces, or preying on frogs, tadpoles, and various invertebrates, such as insect larvae, snails or worms. No predator seems to specialise on P. fluviatile, but a number of animals take it opportunistically, including rats, foxes, weasels, birds of prey and jays. The most significant predator may be mankind, with individual prospectors able to catch 3,000 to 10,000 in one season. (Full article...)
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Zygoballus sexpunctatus is a species of jumping spider which occurs in the southeastern United States where it can be found in a variety of grassy habitats, including old fields, river terrace forests, flatwoods, Florida Sand Pine scrub, Slash Pine forests, Appalachian grass balds and rice fields. The range of the species extends from New Jersey to Florida and west to Texas, although it is most commonly found in the southern states. The specific name is derived from the Latin sex meaning "six" and punctum meaning "spot", in reference to the six spots that typically occur on the abdomen of the male.
Adult spiders measure 3–4.5 mm long. The cephalothorax and abdomen are bronze to black in colour, with reddish brown or yellowish legs. The male has distinctive enlarged chelicerae (the mouthparts used for grasping prey) and front femora (the third, and typically largest, leg segments). Like many jumping spiders, Z. sexpunctatus males exhibit ritualised courtship and agonistic behaviour. (Full article...)
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Spiders (order Araneae) are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms. Approximately 40,000 spider species, and 109 families have been recorded by taxonomists.
Anatomically, spiders differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax and abdomen, and joined by a small, cylindrical pedicel. Unlike insects, spiders do not have antennae. In all except the most primitive group, the Mesothelae, spiders have the most centralized nervous systems of all arthropods, as all their ganglia are fused into one mass in the cephalothorax. Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend them by hydraulic pressure. Their abdomens bear appendages that have been modified into spinnerets that extrude silk from up to six types of silk glands within their abdomen. (Full article...)
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Polish cochineal (Porphyrophora polonica), also known as Polish carmine scales, 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 growing on the sandy soils of Central Europe and other parts of Eurasia. Its primary host plant is the perennial knawel (Scleranthus perennis), but it has also been known to feed on plants of 20 other genera, including mouse-ear hawkweed (Hieracium pilosella), bladder campion (Silene vulgaris), velvet bent (Agrostis canina), Caragana, smooth rupturewort (Herniaria glabra), strawberry (Fragaria), and cinquefoil (Potentilla).
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. Polish cochineal was widely traded in Europe during the Middle Ages and the Renaissance. In the 15th and 16th centuries, along with grain, timber, and salt, it was one of Poland's and Lithuania's chief exports, mainly to southern Germany and northern Italy as well as to France, England, the Ottoman Empire, and Armenia. (Full article...)
Selected article 22
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Colony collapse disorder (CCD) is a phenomenon in which worker bees from a beehive or European honey bee colony abruptly disappear. While such disappearances have occurred throughout the history of apiculture, the term colony collapse disorder was first applied to a drastic rise in the number of disappearances of Western honey bee colonies in North America in late 2006. Colony collapse is economically significant because many agricultural crops worldwide are pollinated by bees.
The cause or causes of the syndrome are not yet fully understood. In 2007 some authorities attributed the problem to biotic factors such as Varroa mites and insect diseases (i.e., pathogens including Nosema apis and Israel acute paralysis virus). Other proposed causes include environmental change-related stresses, malnutrition, pesticides (e.g.. neonicotinoids such as clothianidin and imidacloprid), and migratory beekeeping. (Full article...)
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Nephrops norvegicus, known variously as the Norway lobster, Dublin Bay prawn, langoustine (compare langostino) or scampi, is a slim, orange-pink lobster which 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. In December 1995, the commensal Symbion pandora was discovered attached to the mouthparts of Nephrops norvegicus, and was found to be the first member of a new phylum, Cycliophora, a finding described by Simon Conway Morris as "the zoological highlight of the decade" (Full article...)
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The subphylum Chelicerata constitutes one of the major subdivisions of the phylum Arthropoda, and includes horseshoe crabs, scorpions, spiders and mites. They originated as marine animals, possibly in the Cambrian period, but the first confirmed chelicerate fossils, eurypterids, date from 445 million years ago in the Late Ordovician period. Few species now live in the sea (only the horseshoe crabs, and the sea-spiders if they are considered chelicerates), while more than 77,000 species live on land. The chelicerate bauplan consists of two tagmata – the cephalothorax and the abdomen – although the division between these sections is not apparent in Acari. The chelicerae, which give the group its name, are the only appendages that appear before the mouth. In most sub-groups they are modest pincers used in feeding, but spiders' chelicerae form fangs which are used to inject venom into their prey. (Full article...)
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The external morphology of Lepidoptera is the physiological structure of the bodies of insects belonging to the order Lepidoptera, also known as butterflies and moths. Lepidoptera are distinguished from other orders principally by the presence of scales on the external parts of the body and appendages, especially the wings. Butterflies and moths vary in size from microlepidoptera only a few millimetres long, to conspicuous animals with a wingspan of many inches, such as the Monarch butterfly and Atlas moth.
The larvae – caterpillars – have a toughened (sclerotised) head capsule, chewing mouthparts, and a soft body, that may have hair-like or other projections, 3 pairs of true legs, and up to 5 pairs of prolegs.
Adults have a hardened exoskeleton, except for the abdomen which is less sclerotised. Their mouthparts include a prominent proboscis formed from maxillary galeae, and are adapted for sucking nectar. They have two immobile, multi-faceted compound eyes, and only two simple eyes or ocelli. Antennae are prominent and besides the faculty of smell, act as olfactory radar, and also aid navigation, orientation and balance during flight. (Full article...)
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Lepidoptera is a large order of insects, comprising an estimated 174,250 species in 126 families and 46 superfamilies. It is one of the most widely-recognisable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skippers, and moth-butterflies.
The term "Lepidoptera" was coined by Carl Linnaeus in 1735 and is derived from the Ancient Greek words λεπίδος (scale) and πτερόν (wing). Lepidopteran species are characterised by more than 20 derived features, some of the most apparent being the scales covering their bodies and wings, and a proboscis. The scales are modified, flattened "hairs", and give butterflies and moths their extraordinary variety of colours and patterns. Butterflies and moths are holometabolous, meaning they undergo complete metamorphosis. Mating and the laying of eggs are normally carried out on or near the larval host plants. The larvae are commonly called caterpillars, and are markedly different from their adult moth or butterfly form, having a cylindrical body with a well developed head, mandible mouthparts, and 0–11 (usually 8) pairs of prolegs. (Full article...)
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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...)
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Hemilepistus reaumuri is a species of woodlouse that lives in and around the deserts of North Africa and the Middle East, "the driest habitat conquered by any species of crustacean". It reaches a length of 22 mm (0.87 in) and a width of up to 12 mm (0.47 in), and has seven pairs of legs which hold its body unusually high off the ground. H. reaumuri occurs at great population densities and fills an important niche in the desert ecosystem. It feeds on plant leaves, obtains most of its water from moisture in the air and sand, and is in turn an important prey item for the scorpion Scorpio maurus. H. reaumuri is only able to survive in such arid conditions because it has developed parental care of its offspring. Adults dig burrows which are inhabited by family groups, which are recognised using pheromones. The burrows are 40–50 cm (16–20 in) deep, and the woodlice retreat to the relatively cool and moist conditions of the burrow when surface conditions are unfavourable. The territorial limit of each colony is marked with a faecal embankment. (Full article...)
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Henry Edwards (August 27, 1827 – June 9, 1891), known as "Harry", was an English-born stage actor, writer and entomologist who gained fame in Australia, San Francisco and New York City for his theatre work. He was drawn to theatre early in life and appeared in amateur productions in London. After sailing to Australia, Edwards appeared professionally in Shakespearean plays and light comedies. Throughout his time in England and Australia, he collected insects, and the National Museum of Victoria used the results of his Australian fieldwork as part of the genesis of their collection.
Edwards was a founding member of the Bohemian Club in San Francisco and, after writing a series of influential studies on Pacific coast Lepidoptera, he was elected life member of the California Academy of Sciences. He gained further theatrical renown in New York City, where he also edited three volumes of the journal Papilio and published a major work on butterflies. His large collection of specimens laid the foundation of the American Museum of Natural History's Lepidoptera studies. Edwards' appreciation of Shakespeare was expressed in the designation of new insect species, favouring female character names from Shakespeare's plays. (Full article...)
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Sphecius grandis, also called the western cicada killer, is a colony-forming species of wasp in the genus Sphecius (cicada killer wasps). It shares the same nesting biology as its congener the eastern cicada killer, S. speciosus. S. grandis, like all other species in the genus, mainly provides cicadas for their offspring. It is colonial, mating brooding once a year, in July and early August. Adults are typically 3–5 cm (1.2–2.0 in) long, and amber-yellow with yellow rings on the abdomen.
Members of the genus Sphecius are not habitually aggressive and save their venom for cicadas which they paralyse and take back to their nests. The female catches around four or more cicadas for provisioning, places them in her brood cells and then proceeds to lay eggs in her cells. The species is endemic to Central America and the Western United States, and is found at a higher mean altitude than other species of Sphecius. The males emerge earlier than females, but generally die after only a couple of days. (Full article...)
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Maevia inclemens is a relatively common and colourful jumping spider found in North America. Males exist in two forms – a "tufted" morph with a black body and pedipalps, three black tufts across its head, and pale legs, and a "grey" morph with black and white stripes on the body and legs, orange palps, and no tufts. The two forms also use different courting displays. Each form accounts for 50% of the adult males, and they are equally successful in mating. Females of Maevia inclemens are 6.5 to 8.0 millimetres (0.26 to 0.31 in) long, while males are 4.75 to 6.5 millimetres (0.19 to 0.26 in) long.
M. inclemens is one of 11 species in genus Maevia. It was originally called Attus inclemens, and other names have been used. The two male forms look and behave so differently that they were originally considered two distinct species. The species is found in southwestern Canada and its distribution in the United States forms a crescent from the northern Midwest through New England and south to Florida. M. inclemens has been able to establish itself in man-made structures such as outbuildings or fences. (Full article...)
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Johngarthia lagostoma is a species of terrestrial crab that lives on Ascension Island and three other islands in the South Atlantic. It grows to a carapace width of 110 mm (4.3 in) on Ascension Island, where it is the largest native land animal. It exists in two distinct colour morphs, one yellow and one purple, with few intermediates. The yellow morph dominates on Ascension Island, while the purple morph is more frequent on Atol das Rocas. The species differs from other Johngarthia species by the form of the third maxilliped.
J. lagostoma lives in burrows among vegetation, at altitudes of up to 400 m (1,300 ft), emerging at night to feed on plant matter and occasionally on animals. From January to March there is an annual migration to the sea to release the planktonic larvae. The species was first described (as Gecarcinus lagostoma) by Henri Milne-Edwards in 1837 from material sent to him by the naturalists Jean René Constant Quoy and Joseph Paul Gaimard, collected by the French ship Astrolabe. (Full article...)
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The coconut crab, Birgus latro, is a species of terrestrial hermit crab, also known as the "robber crab" or "palm thief". It is the largest land-living arthropod in the world, and is probably at the upper size limit of terrestrial animals with exoskeletons in today's atmosphere at a weight of up to 4.1 kg (9.0 lb). It is found on islands across the Indian Ocean and parts of the Pacific Ocean as far east as the Gambier Islands, mirroring the distribution of the coconut palm. Adults develop a tough exoskeleton on their abdomen and stop carrying a shell. They cannot swim, and will drown if immersed in water for long. Sexual maturity is reached after about 5 years, and the total lifespan may be over 60 years.
Adult coconut crabs feed on fruits, nuts, seeds, and the pith of fallen trees, but will eat carrion and other organic matter opportunistically. The species is popularly associated with the coconut, and has been widely reported to climb trees to pick coconuts, which it then opens to eat the flesh. While coconut crabs can climb trees, and can eventually open a coconut collectively, coconuts are not a significant part of their diet. Coconut crabs are hunted wherever they come into contact with humans, and are subject to legal protection in some areas. In the absence of precise information, the IUCN lists the species as Data Deficient. (Full article...)
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Seychellum alluaudi is a species of freshwater crab endemic to the Seychelles, and the only true freshwater crab in that country. It lives in rainforest streams on the archipelago's granitic high islands. Although it may be abundant, little is known about its biology, and it is currently listed as Least Concern on the IUCN Red List. Adults are dark yellow to brown in colour, and have a quadrangular carapace with a width of around 50 mm (2 in). The claws are unequal in size.
S. alluaudi was described as a species of Deckenia in 1893 and 1894, and later split off into the monotypic segregate genus Seychellum. Its closest relatives are the two species currently in Deckenia, both of which are found in East Africa. Several hypotheses have been published to explain how Seychellum reached its isolated location; some means of transport across the open ocean is considered the most likely explanation. Seychellum differs from Deckenia in a number of characters, including the lengths of the legs and antennae, and the fact that Deckenia species have flattened legs, compared to those of Seychellum. (Full article...)
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Caprella mutica, commonly known as the Japanese skeleton shrimp, is a species of skeleton shrimp. It is a relatively large caprellids, reaching a maximum length of 50 mm (2.0 in). The species is sexually dimorphic, with the males usually being much larger than the females. It is characterised by their "hairy" first and second thoracic segments and the rows of spines on their bodies. Body colour ranges from green to red to blue, depending on the environment. It is an omnivorous, highly adaptable, opportunistic feeder. In turn, it provides a valuable food source for fish, crabs, and other larger predators. C. mutica is usually found in dense colonies attached to submerged man-made structures, floating seaweed, and other organisms.
C. mutica is native to shallow protected bodies of water in the Sea of Japan. In as little as 40 years, it has become an invasive species in the North Atlantic, North Pacific, and along the coasts of New Zealand. It is believed to have been accidentally introduced to these areas through the global maritime traffic and aquaculture. Outside of its native range, C. mutica is often exclusively synanthropic, being found in large numbers in and around areas of human activity. Its ecological and economic impact as an invasive species is unknown, but it poses a serious threat to native populations of skeleton shrimp in the affected areas. (Full article...)
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Waptia fieldensis is an extinct species of arthropod from the Middle Cambrian Burgess Shale Lagerstätte of Canada. It grew to a length of about 8 cm (3 in) and resembled modern shrimp in both morphology and habit. It had a large bivalved carapace and a segmented body terminating into a pair of tail flaps. It was an active swimmer, feeding on organic particles it gathers from the seafloor substrate.
Based on the number of individuals, Waptia fieldensis is the third most abundant arthropod from the Burgess Shale Formation, with thousands of specimens collected. It was among the first fossils found by the American paleontologist Charles D. Walcott in 1909. He described it in 1912 and named it after two mountains near the discovery site – Wapta Mountain and Mount Field.
Waptia fieldensis is the only species classified under the genus Waptia. Although it bears a remarkable resemblance to modern crustaceans, its taxonomic affinities remain unclear. It is currently classified as a stem group crustacean and tentatively included in the clade Crustaceomorpha. (Full article...)
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Metanephrops challengeri (commonly known as the New Zealand lobster or New Zealand scampi) is a species of slim, pink lobster that lives around the coast of New Zealand. It is typically 13–18 cm (5–7 in) long and weighs around 100 g (3.5 oz). The carapace and abdomen are smooth, and adults are white with pink and brown markings and a conspicuous pair of long, slim claws. M. challengeri lives in burrows at depths of 140–640 m (460–2,100 ft) in a variety of sediments. Although individuals can live for up to 15 years, the species shows low fecundity, where small numbers of larvae hatch at an advanced stage.
M. challengeri is a significant prey item for ling, as well as being an important fishery species for human consumption; trawlers catch around 1,000 t (2,200,000 lb) per year under the limitations of New Zealand's Quota Management System. The species was first collected by the Challenger expedition of 1872–1876, but only described as separate from related species by Heinrich Balss in 1914. Although originally classified in the genus Nephrops, it was moved in 1972 to a new genus, Metanephrops, along with most other species then classified in Nephrops. (Full article...)
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Dyspanopeus sayi is a species of mud crab that is native to the Atlantic coast of North America. It has also become established outside its native range, living in Swansea Docks since 1960, the Mediterranean Sea since the 1970s, the North Sea since 2007 and the Black Sea since 2010. It can reach a carapace width of 20 mm (0.8 in), and has black tips to its unequal claws. It feeds on bivalves and barnacles, and is in turn eaten by predators including the Atlantic blue crab, Callinectes sapidus. Eggs are produced from spring to autumn, the offspring reach sexual maturity the following summer, and individuals can live for up to two years. The closest relative of D. sayi is D. texanus, which lives in the Gulf of Mexico; the two species differ in subtle features of the genitalia and the last pair of walking legs. (Full article...)
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The Sirex woodwasp, Sirex noctilio, is a species of horntail, native to Europe, Asia and northern Africa. Adults vary in length from 9 to 36 millimetres (0.4 to 1.4 in). It is an invasive species in many parts of the world including Australia, New Zealand, North America, South America and South Africa, where it has become a significant economic pest of pine trees. It can attack a wide variety of pine species, although some species seem to be more susceptible than others, and it is often stressed trees that are attacked.
During oviposition, the female wasp lays two eggs with or without a mucoid substance and a symbiotic fungus for the larvae to feed on once they hatch. The mucoid substance is toxic to trees and aids in tree decline. The ascospores from the symbiotic fungus Amylostereum areolatum are also pathogenic. (Full article...)
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Opabinia is an extinct stem-arthropod genus found in Cambrian fossil deposits. The only known species, O. regalis, is known from the Middle Cambrian Burgess Shale Lagerstätte of British Columbia, Canada. Fewer than twenty good specimens have been described; 3 specimens of Opabinia are known from the Greater Phyllopod bed, where they comprise less than 0.1% of the community. Opabinia was a soft-bodied animal of modest size, and its segmented body had lobes along the sides and a fan-shaped tail. The head shows unusual features: five eyes, a mouth under the head and facing backwards, and a proboscis that probably passed food to the mouth. Opabinia probably lived on the seafloor, using the proboscis to seek out small, soft food.
When the first thorough examination of Opabinia in 1975 revealed its unusual features, it was thought to be unrelated to any known phylum, although possibly related to a hypothetical ancestor of arthropods and of annelid worms. However other finds, most notably Anomalocaris, suggested that it belonged to a group of animals that were closely related to the ancestors of arthropods and of which the living animals onychophorans and tardigrades may also be members. (Full article...)