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...)
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The bush coconut, or bloodwood apple, is an Australian bush tucker food. It is an insect gall with both plant and animal components: an adult female scale insect and her offspring (of genus Cystococcus) live in a gall induced on a bloodwood eucalypt tree (Corymbia). Bush coconuts can vary from golf ball to tennis ball size. They have a hard and lumpy outer layer. The inner layer is a white flesh that contains the female insect and her offspring. There are three known species of Cystococcus responsible for forming the bush coconut: Cystococcus pomiformis, Cystococcus echiniformis and Cystococcus campanidorsalis. C. pomiformis is the most common species. The bush coconut is found in Western Australia, the Northern Territory, Queensland and New South Wales.
The bush coconut is picked from the host tree and cracked open to allow the flesh and scale insects to be eaten. Both have a high protein content and are used as a food source by humans and other animals. The name ‘bush coconut’ is derived from the white flesh of the inner layer, which is similar in appearance to that of a coconut, and the taste of the flesh has been said to have a coconut flavour. The bush coconut has been depicted in Indigenous Australian dreaming and used as inspiration in their artwork. (Full article...)
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Agelenopsis aperta, also known as the desert grass spider or funnel-web spider, is a species of spider belonging to the family Agelenidae and the genus Agelenopsis. It is found in dry and arid regions across the southern United States and into northwestern Mexico. Their body is about 13–18 mm long and they have relatively long legs in order to run after their prey. Desert grass spiders can withstand very low temperatures even though they do not cold harden. It constructs the characteristic funnel-shaped webs in crevices where the funnel will fit, where they wait in the tube for prey which they can run after using their long legs. They often hunt for their prey at night.
A. aperta is known for its territoriality and will fight intruders to protect their space. A. aperta are mainly monogamous, and the male performs an elaborate courtship ritual that involves swaying his abdomen and releasing pheromones. The male's pheromones induce a cataplectic state in the female, and then once the female is active again, they begin to mate. Desert grass spiders inject venom into their prey which results in rapid paralysis. Bites to humans, however, are not well-studied and are currently considered harmless. The agatoxin present in its venom has been researched extensively and is known to block calcium channels. (Full article...)
Afraflacilla braunsi is a species of jumping spider in the genusAfraflacilla. First found in South Africa, the spider was subsequently observed living in Saudi Arabia, Turkmenistan, the United Arab Emirates and Yemen, although it is likely to have a wider distribution. First described in 1903 by George and Elizabeth Peckham, it was originally allocated to the genus Pseudicius with the name Pseudicius braunsii. After being renamed Icius braunsi in 1987, it was finally given its current name by Jerzy Prószyński in 2017. Pseudicius tripunctatus, now called Afraflacilla tripunctatus, is a synonym.
A small to medium-sized spider, Afraflacilla braunsi has a carapace that is between 1.7 and 1.9 mm (0.07 and 0.07 in) long and an abdomen 2.2 and 3.2 mm (0.09 and 0.13 in) long. The carapace is brown, sometimes with yellow sides. The abdomen is light brown or fawn with lighter yellow patches. It has large brown front legs, the remainder generally yellow and less robust. It makes noises by rubbing its forelegs against small hairs under its eyes. The copulatory organs are distinctive for the species. The male has a characteristically bulbous palpal bulb and a single long projection, or apophysis, extending from the palpal tibia. The female has very long and coiled insemination ducts that lead to large spermathecae. (Full article...)
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Insects are the only group of invertebrates that have evolved wings and flight. Insects first flew in the Carboniferous, some 300 to 350 million years ago, making them the first animals to evolve flight. Wings may have evolved from appendages on the sides of existing limbs, which already had nerves, joints, and muscles used for other purposes. These may initially have been used for sailing on water, or to slow the rate of descent when gliding.
Two insect groups, the dragonflies and the mayflies, have flight muscles attached directly to the wings. In other winged insects, flight muscles attach to the thorax, which make it oscillate in order to induce the wings to beat. Of these insects, some (flies and some beetles) achieve very high wingbeat frequencies through the evolution of an "asynchronous" nervous system, in which the thorax oscillates faster than the rate of nerve impulses.
Portia labiata is a jumping spider (family Salticidae) found in Sri Lanka, India, southern China, Burma (Myanmar), Malaysia, Singapore, Java, Sumatra and the Philippines. In this medium-sized jumping spider, the front part is orange-brown and the back part is brownish. The conspicuous main eyes provide vision more acute than a cat's during the day and 10 times more acute than a dragonfly's, and this is essential in P. labiata′s navigation, hunting and mating.
The genusPortia has been called "eight-legged cats", as their hunting tactics are as versatile and adaptable as a lion's. All members of Portia have instinctive hunting tactics for their most common prey, but often can improvise by trial and error against unfamiliar prey or in unfamiliar situations, and then remember the new approach. While most jumping spiders prey mainly on insects and by active hunting, females of Portia also build webs to catch prey directly and sometimes join their own webs on to those of web-based spiders. Both females and males prefer web spiders as prey, followed by other jumping spiders, and finally insects. In all cases females are more effective predators than males.
Populations from Los Baños and from Sagada, both in the Philippines, have slightly different hunting tactics. In laboratory tests, Los Baños P. labiata relies more on trial and error than Sagada P. labiata in finding ways to vibrate the prey's web and thus lure or distract the prey. Around Los Baños the web-building Scytodes pallida, which preys on jumping spiders, is very abundant, and spits a sticky gum on prey and potential threats. A P. labiata from Los Baños instinctively detours round the back of S. pallida while with plucking the web in a way that makes the prey believe the threat is in front of it. In areas where S. pallida is absent, the local members of P. labiata do not use this combination of deception and detouring for a stab in the back. In a test to explore P. labiata′s ability to solve a novel problem, a miniature lagoon was set up, and the spiders had to find the best way to cross it. Specimens from Sagada, in the mountains, almost always repeated the first option they tried, even when that was unsuccessful. When specimens from Los Baños, beside a lake, were unsuccessful the first time, about three quarters switched to another option. (Full article...)
It had several unique characteristics that differentiated it from many other arthropods, such as its long parabolic (nearly U-shaped) prosoma (head), its elongated first and second segments and the presence of paired "ridges" in the surface of its third to tenth tergites (dorsal halves of the segments). Furthermore, the opisthosoma (the "trunk") of Borchgrevinkium was triangular, and its telson (the posteriormost division of its body), short and wedge-shaped. It was a small animal, approximately 3 centimetres (1.2 inches) long.
The only known specimen of the genus was collected in 1956 and described in 1959 by the Russian paleontologistNestor Ivanovich Novojilov. He determined that it was a eurypterid and classified it in the familyMycteroptidae. However, its classification changed repeatedly over the years, being transferred from Eurypterida to Xiphosura and back to Eurypterida some time later. Borchgrevinkium is tentatively considered as a prosomapod, with more fossil material needed to ensure its current classification. (Full article...)
Horse-flies and deer flies are true flies in the family Tabanidae in the insectorderDiptera. The adults are often large and agile in flight. Only female horseflies bite land vertebrates, including humans, to obtain blood. They prefer to fly in sunlight, avoiding dark and shady areas, and are inactive at night. They are found all over the world except for some islands and the polar regions (Hawaii, Greenland, Iceland). Both horse-flies and botflies (Oestridae) are sometimes referred to as gadflies.
Adult horse-flies feed on nectar and plant exudates; males have weak mouthparts, but females have mouthparts strong enough to bite large animals. This is for the purpose of obtaining enough protein from blood to produce eggs. The mouthparts of females are formed into a stout stabbing organ with two pairs of sharp cutting blades, and a spongelike part used to lap up the blood that flows from the wound. The larvae are predaceous and grow in semiaquatic habitats.
Polistes exclamans, the Guinea paper wasp, is a socialwasp 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...)
Mantises are an order (Mantodea) of insects that contains over 2,400 species in about 460 genera in 33 families. The largest family is the Mantidae ("mantids"). Mantises are distributed worldwide in temperate and tropical habitats. They have triangular heads with bulging eyes supported on flexible necks. Their elongated bodies may or may not have wings, but all Mantodea have forelegs that are greatly enlarged and adapted for catching and gripping prey; their upright posture, while remaining stationary with forearms folded, has led to the common name praying mantis.
The closest relatives of mantises are termites and cockroaches (Blattodea), which are all within the superorderDictyoptera. Mantises are sometimes confused with stick insects (Phasmatodea), other elongated insects such as grasshoppers (Orthoptera), or other more distantly related insects with raptorial forelegs such as mantisflies (Mantispidae). Mantises are mostly ambush predators, but a few ground-dwelling species are found actively pursuing their prey. They normally live for about a year. In cooler climates, the adults lay eggs in autumn, then die. The eggs are protected by their hard capsules and hatch in the spring. Females sometimes practice sexual cannibalism, eating their mates after copulation.
Locusts (derived from the Latinlocusta, locust or lobster) are various species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstances they become more abundant and change their behaviour and habits, becoming gregarious. No taxonomic distinction is made between locust and grasshopper species; the basis for the definition is whether a species forms swarms under intermittently suitable conditions; this has evolved independently in multiple lineages, comprising at least 18 genera in 5 different subfamilies.
Normally, these grasshoppers are innocuous, their numbers are low, and they do not pose a major economic threat to agriculture. However, under suitable conditions of drought followed by rapid vegetation growth, serotonin in their brains triggers dramatic changes: they start to breed abundantly, becoming gregarious and nomadic (loosely described as migratory) when their populations become dense enough. They form bands of wingless nymphs that later become swarms of winged adults. Both the bands and the swarms move around, rapidly strip fields, and damage crops. The adults are powerful fliers; they can travel great distances, consuming most of the green vegetation wherever the swarm settles.
Locusts have formed plagues since prehistory. The ancient Egyptians carved them on their tombs and the insects are mentioned in the Iliad, the Mahabharata, the Bible and Quran. Swarms have devastated crops and have caused famines and human migrations. More recently, changes in agricultural practices and better surveillance of locust breeding grounds have allowed control measures at an early stage. Traditional locust control uses insecticides from the ground or air, but newer biological control methods are proving effective. Swarming behaviour decreased in the 20th century, but despite modern surveillance and control methods, swarms can still form; when suitable weather conditions occur and vigilance lapses, plagues can occur. (Full article...)
Engraving captioned Urania riphaeus from Charles D. d'Orbigny's Dictionnaire universel d'histoire naturelle (1849)
Chrysiridia rhipheus, the Madagascan sunset moth, is a species of day-flying moth of the family Uraniidae. It is considered one of the most impressive and appealing-looking lepidopterans. Famous worldwide, it is featured in most coffee table books on Lepidoptera and is much sought after by collectors, though many older sources misspell the species name as "ripheus". The colours originate from optical interference in the iridescent parts of the wings, while the black parts are pigmented. Adults have a wingspan of 7–9 cm (2.8–3.5 in).
Dru Drury, who described the moth in 1773, placed it in the genus Papilio, considering it a butterfly. 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. Females lay about 80 eggs under the leaves of Omphaleaspp. The caterpillars are whitish yellow with black spots and red feet and are covered in club-ended black setae. Silk spun from the mouth helps the caterpillars hold on to smooth leaves and climb back to the plant when they fall. After completing four instars, the caterpillars spin an open network cocoon. The pupal stage lasts from 17 to 23 days. Chrysiridia rhipheus is the sole specialist herbivore of the four species of Omphalea in Madagascar. Omphalea is toxic: the toxins are sequestered by the feeding caterpillar and retained in the pupal and adult stages. Thousands of these moths migrate between the eastern and western ranges of their host plants. (Full article...)
The orderEmbioptera, commonly known as webspinners or footspinners, are a small group of mostly tropical and subtropicalinsects, classified under the subclassPterygota. The order has also been called Embiodea or Embiidina. More than 400 species in 11 families have been described, the oldest known fossils of the group being from the mid-Jurassic. Species are very similar in appearance, having long, flexible bodies, short legs, and only males having wings.
Webspinners are gregarious, living subsocially in galleries of fine silk which they spin from glands on their forelegs. Members of these colonies are often related females and their offspring; adult males do not feed and die soon after mating. Males of some species have wings and are able to disperse, whereas the females remain near where they were hatched. Newly mated females may vacate the colony and found a new one nearby. Others may emerge to search for a new food source to which the galleries can be extended, but in general, the insects rarely venture from their galleries. (Full article...)
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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Male M. campanulae
Megachile campanulae, known as the bellflower resin bee, is a species of bee in the family Megachilidae. Described in 1903, these solitary bees are native to eastern North America. Studies in 2013 placed them among the first insect species to use synthetic materials for making nests. They are considered mason bees, which is a common descriptor of bees in several families, including Megachilidae. Within the genus Megachile, frequently also referred to as leafcutter bees, M. campanulae is a member of the subgenus Chelostomoides, which do not construct nests from cut leaves, but rather from plant resins and other materials. Females lay eggs in nests constructed with individual cell compartments for each egg. Once hatched, the eggs progress through larval stages and subsequently will overwinter as pupae. The bees are susceptible to parasitism from several other bee species, which act as brood parasites. They are medium-sized bees and the female adults are typically larger than the males. They are important pollinators of numerous native plant species throughout their range. (Full article...)
Image 2Formation 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 4 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 6Mature 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 8Ghost 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 13The house centipedeScutigera 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 14This 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 18Body structure of a typical crustacean – krill (from Crustacean)
Image 19In honeypot antrepletes, 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 23Some 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)
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.
The head and mandibles of an Australianbull 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.
A nest of the tropical Asian giant honey bee, which consists of a single exposed honeycomb, an array of densely packed hexagonal cells made of beeswax. Honeycombs store food (honey and pollen) and house the "brood" (eggs, larvae, and pupae).
The Forest scorpion (Cercophonius squama) is a scorpion native to southeastern Australia and Tasmania. The body is 25 to 40 millimetres (0.98 to 1.57 in) long, and coloured creamy yellow to orange brown with dark brown variegations. The legs are yellow with some dark brown pigment.
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.
The Painted Lady (Vanessa cardui) is a well-known colourful butterfly, found on every continent except Antarctica. It occurs in any temperate zone, including mountains in the tropics. The species is resident only in warmer areas, but migrates in spring, and sometimes again in autumn.
The red rock crab (Grapsus grapsus) is one of the most common crabs along the western coast of the Americas. Adults are quite variable in color, including brownish-red, mottled or spotted brown, pink, yellow, bright orange and red. It feeds on algae primarily, sometimes sampling other plant matter and dead animals.
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.
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).
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.
A female subimago of a March Brown mayfly (Rhithrogena germanica). Mayflies belong to the orderEphemeroptera, and the only insects that have a subimago phase. This stage is a favourite food of many fish, and many fishing flies are modeled to resemble them. They are aquatic insects whose nymph stage usually lasts one year in freshwater. The adults are short-lived, from as little as thirty minutes to a few days depending on the species.
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.
Anthidium florentinum, a species of bee in the family Megachilidae. Bees are flying insects closely related to wasps and ants that are involved in pollination. There are nearly 20,000 known species of bees in seven recognized biological families. Bees are found on every continent except Antarctica, in every habitat on the planet that contains insect-pollinated flowering plants. Bees range in size from tiny stingless bee species whose workers are less than 2 millimetres (0.08 in) long, to Megachile pluto, whose females can attain a length of 39 millimetres (1.54 in).
Compound eyes on a blue bottle fly. Unlike simple eyes, which have a single concave photoreceptive surface, compound eyes consist of a number of individual lenses (called ommatidia) laid out on a convex surface; this means that they point in slightly different directions. Compound eyes provide a wide field of view and can detect fast movement, but have low resolution.
Gonepteryx rhamni, also known as the common brimstone, is a butterfly in the family Pieridae. It lives throughout the Palearctic zone and is commonly found across Europe, Asia and North Africa. The butterfly relies on two species of buckthorn as hosts for its eggs and larvae, which influences its geographic range and distribution as these plants are commonly found in wetlands. After spending the summer feeding, adults travel to woodland areas to spend seven months hibernating. In spring when their host plants have developed, they return to the wetlands to breed and lay eggs. Both the larval and adult forms of the species have protective coloration and behaviour that decreases their chances of being recognised and preyed upon. The adult common brimstone has sexual dichromism in its wing coloration and iridescence; the male (pictured) has yellow wings and iridescence, while females have greenish-white wings and are not iridescent.
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.
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".
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