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72-835: Stenurothripidae is a family of thrips belonging to the suborder Terebrantia in the order Thysanoptera . The oldest genera of this group are known from the Early Cretaceous Lebanese and Spanish San Just amber . Genera: Thrips Terebrantia Tubulifera Physopoda Thrips ( order Thysanoptera ) are minute (mostly 1 mm (0.039 in) long or less), slender insects with fringed wings and unique asymmetrical mouthparts. Entomologists have described approximately 7,700 species. They fly only weakly and their feathery wings are unsuitable for conventional flight; instead, thrips exploit an unusual mechanism, clap and fling , to create lift using an unsteady circulation pattern with transient vortices near

144-456: A distinctive silvery or bronze scarring on the surfaces of the stems or leaves where the thrips have fed. The mouthparts of thrips have been described as “rasping-sucking”, “punching and sucking”, or, simply just a specific type of “piercing-sucking” mouthparts. Thysanoptera is divided into two suborders, Terebrantia and Tubulifera; these can be distinguished by morphological, behavioral, and developmental characteristics. Tubulifera consists of

216-440: A dozen of the described species are known to vector tospoviruses. These enveloped viruses are considered among some of the most damaging of emerging plant pathogens around the world, with those vector species having an outsized impact on human agriculture. Virus members include the tomato spotted wilt virus and the impatiens necrotic spot viruses. The western flower thrips, Frankliniella occidentalis , has spread until it now has

288-407: A fringe of bristles. The wings are folded back over the body at rest. Their legs usually end in two tarsal segments with a bladder-like structure known as an "arolium" at the pretarsus. This structure can be everted by means of hemolymph pressure, enabling the insect to walk on vertical surfaces. They have compound eyes consisting of a small number of ommatidia and three ocelli or simple eyes on

360-695: A fungus-feeding ancestor during the Mesozoic, and many groups still feed upon and inadvertently redistribute fungal spores. These live among leaf litter or on dead wood and are important members of the ecosystem , their diet often being supplemented with pollen . Other species are primitively eusocial and form plant galls and still others are predatory on mites and other thrips. Two species of Aulacothrips , A. tenuis and A. levinotus , have been found to be ectoparasites on aetalionid and membracid plant-hoppers in Brazil. Akainothrips francisi of Australia

432-424: A median bristle or empodium , meaning the meeting place of the pulvilli. On the underside of the tarsal segments, there frequently are pulvillus-like organs or plantulae . The arolium, plantulae and pulvilli are adhesive organs enabling their possessors to climb smooth or steep surfaces. They all are outgrowths of the exoskeleton and their cavities contain blood. Their structures are covered with tubular tenent hairs,

504-591: A phylogeny based on ribosomal DNA and three proteins in 2012, supports the monophyly of the two suborders, Tubulifera and Terebrantia. In Terebrantia, Melanothripidae may be sister to all other families, but other relationships remain unclear. In Tubulifera, the Phlaeothripidae and its subfamily Idolothripinae are monophyletic. The two largest thrips subfamilies, Phlaeothripinae and Thripinae, are paraphyletic and need further work to determine their structure. The internal relationships from these analyses are shown in

576-401: A shared, derived character , so uniramous arthropods were grouped into a taxon called Uniramia . It is now believed that several groups of arthropods evolved uniramous limbs independently from ancestors with biramous limbs, so this taxon is no longer used. Arachnid legs differ from those of insects by the addition of two segments on either side of the tibia, the patella between the femur and

648-404: A single family, Phlaeothripidae ; members can be identified by their characteristic tube-shaped apical abdominal segment, egg-laying atop the surface of leaves, and three "pupal" stages. In the Phlaeothripidae, the males are often larger than females and a range of sizes may be found within a population. The largest recorded phlaeothripid species is about 14 mm long. Females of the eight families of

720-508: A single series of segments attached end-to-end. A biramous limb, however, branches into two, and each branch consists of a series of segments attached end-to-end. The external branch (ramus) of the appendages of crustaceans is known as the exopod or exopodite , while the internal branch is known as the endopod or endopodite . Other structures aside from the latter two are termed exites (outer structures) and endites (inner structures). Exopodites can be easily distinguished from exites by

792-479: A single thrips. Other common names for thrips include thunderflies, thunderbugs, storm flies, thunderblights, storm bugs, corn fleas, corn flies, corn lice, freckle bugs, harvest bugs, and physopods. The older group name "physopoda" references the bladder-like tips to the tarsi of the legs. The name of the order, Thysanoptera , is constructed from the ancient Greek words θύσανος , thysanos , "tassel or fringe", and πτερόν , pteron , "wing", with reference to

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864-422: A tarsal claw. Myriapod legs show a variety of modifications in different groups. In all centipedes, the first pair of legs is modified into a pair of venomous fangs called forcipules. In most millipedes, one or two pairs of walking legs in adult males are modified into sperm-transferring structures called gonopods . In some millipedes, the first leg pair in males may be reduced to tiny hooks or stubs, while in others

936-462: A worldwide distribution, and is the primary vector of plant diseases caused by tospoviruses. Other viruses that they spread include the genera Ilarvirus , (Alpha |Beta |Gamma)carmovirus , Sobemovirus and Machlomovirus . Their small size and predisposition towards enclosed places makes them difficult to detect by phytosanitary inspection , while their eggs, laid inside plant tissue, are well-protected from pesticide sprays. When coupled with

1008-588: Is a factor that affects the reproductive mode. Several normally bisexual species have become established in the United States with only females present. Many thrips are pests of commercial crops due to the damage they cause by feeding on developing flowers or vegetables, causing discoloration, deformities, and reduced marketability of the crop. Some thrips serve as vectors for plant diseases, such as tospoviruses . Over 20 plant-infecting viruses are known to be transmitted by thrips, but perversely, less than

1080-424: Is a parasite within the colonies of another thrips species Dunatothrips aneurae that makes silken nests or domiciles on Acacia trees. A number of thrips in the subfamily Phlaeothripinae that specialize on Acacia hosts produce silk with which they glue together phyllodes to form domiciles inside which their semi-social colonies live. Mirothrips arbiter has been found in paper wasp nests in Brazil. The eggs of

1152-407: Is adapted for running ( cursorial ), rather than for digging, leaping, swimming, predation, or other similar activities. The legs of most cockroaches are good examples. However, there are many specialized adaptations, including: The embryonic body segments ( somites ) of different arthropods taxa have diverged from a simple body plan with many similar appendages which are serially homologous, into

1224-497: Is considerable breadth in host affinity across the order, and even within a species, varying degrees of fidelity to a host. Family Thripidae in particular is notorious for members with broad host ranges, and the majority of pest thrips come from this family. For example, Thrips tabaci damages crops of onions , potatoes , tobacco , and cotton . Some species of thrips create galls , almost always in leaf tissue. These may occur as curls, rolls or folds, or as alterations to

1296-424: Is not uncommon for some species (e.g., Frankliniella tritici and Limothrips cerealium ) to "bite" humans under such circumstances. Although no species feed on blood and no known animal disease is transmitted by thrips, some skin irritation has been described. Thrips develop resistance to insecticides easily and there is constant research on how to control them. This makes thrips ideal as models for testing

1368-491: Is the fourth section of the typical insect leg. As a rule, the tibia of an insect is slender in comparison to the femur, but it generally is at least as long and often longer. Near the distal end, there is generally a tibial spur, often two or more. In the Apocrita , the tibia of the foreleg bears a large apical spur that fits over a semicircular gap in the first segment of the tarsus. The gap is lined with comb-like bristles, and

1440-428: Is the possibility of being trapped by water. Thrips have non-wetting bodies and have the ability to ascend a meniscus by arching their bodies and working their way head-first and upwards along the water surface in order to escape. Thrips lay extremely small eggs, about 0.2 mm long. Females of the suborder Terebrantia cut slits in plant tissue with their ovipositor, and insert their eggs, one per slit. Females of

1512-558: Is the sole pollinator of Wilkiea huegeliana , a small, unisexual annually flowering tree or shrub in the rainforests of eastern Australia. T. setipennis serves as an obligate pollinator for other Australian rainforest plant species, including Myrsine howittiana and M. variabilis . The genus Cycadothrips is a specialist pollinator of cycads , which are normally wind pollinated but some species of Macrozamia are able to attract thrips to male cones at some times and repel them so that they move to female cones. Thrips are likewise

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1584-465: The Apterygota , the legs of immature specimens are in effect smaller versions of the adult legs. A representative insect leg, such as that of a housefly or cockroach , has the following parts, in sequence from most proximal to most distal : Associated with the leg itself there are various sclerites around its base. Their functions are articular and have to do with how the leg attaches to

1656-519: The Cerylonidae have four tarsomeres on each tarsus. The distal segment of the typical insect leg is the pretarsus. In the Collembola , Protura and many insect larvae, the pretarsus is a single claw. On the pretarsus most insects have a pair of claws ( ungues , singular unguis ). Between the ungues, a median unguitractor plate supports the pretarsus. The plate is attached to the apodeme of

1728-847: The Eulophidae and the Trichogrammatidae . Other biocontrol agents of adults and larvae include anthocorid bugs of genus Orius , and phytoseiid mites. Biological insecticides such as the fungi Beauveria bassiana and Verticillium lecanii can kill thrips at all life-cycle stages. Insecticidal soap spray is effective against thrips. It is commercially available or can be made of certain types of household soap. Scientists in Japan report that significant reductions in larva and adult melon thrips occur when plants are illuminated with red light. Arthropod leg Homologies of leg segments between groups are difficult to prove and are

1800-594: The Ginkgoales as early as 110-105 Mya, in the Cretaceous. Cenomanithrips primus , Didymothrips abdominalis and Parallelothrips separatus are known from Myanmar amber of the Cenomanian age. Thrips are generally considered to be the sister group to Hemiptera (bugs). The phylogeny of thrips families has been little studied. A preliminary analysis in 2013 of 37 species using 3 genes, as well as

1872-563: The Permian Permothrips longipennis , although it probably not a member of this group. By the Early Cretaceous , true thrips became much more abundant. The extant family Merothripidae most resembles these ancestral Thysanoptera, and is probably basal to the order. There are currently over six thousand species of thrips recognized, grouped into 777 extant and sixty fossil genera. Some thrips were pollinators of

1944-623: The Scarabaeidae and Dytiscidae have thoracic legs, but no prolegs. Some insects that exhibit hypermetamorphosis begin their metamorphosis as planidia , specialised, active, legged larvae, but they end their larval stage as legless maggots, for example the Acroceridae . Among the Exopterygota , the legs of larvae tend to resemble those of the adults in general, except in adaptations to their respective modes of life. For example,

2016-473: The tarsal organ . The situation is identical in scorpions , but with the addition of a pre-tarsus beyond the tarsus. The claws of the scorpion are not truly legs, but are pedipalps , a different kind of appendage that is also found in spiders and is specialised for predation and mating. In Limulus , there are no metatarsi or pretarsi, leaving six segments per leg. The legs of crustaceans are divided primitively into seven segments, which do not follow

2088-490: The 17th century, and a sketch was made by Philippo Bonanni, a Catholic priest, in 1691. Swedish entomologist Baron Charles De Geer described two species in the genus Physapus in 1744, and Linnaeus in 1746 added a third species and named this group of insects Thrips . In 1836 the Irish entomologist Alexander Henry Haliday described 41 species in 11 genera and proposed the order name of Thysanoptera. The first monograph on

2160-470: The Odonata. In parasitic Hymenoptera, the base of the femur has the appearance of a second trochanter. In most insects, the femur is the largest region of the leg; it is especially conspicuous in many insects with saltatorial legs because the typical leaping mechanism is to straighten the joint between the femur and the tibia, and the femur contains the necessary massive bipennate musculature. The tibia

2232-459: The Terebrantia all possess the eponymous saw-like (see terebra ) ovipositor on the anteapical abdominal segment, lay eggs singly within plant tissue, and have two "pupal" stages. In most Terebrantia, the males are smaller than females. The family Uzelothripidae has a single species and it is unique in having a whip-like terminal antennal segment. The earliest fossils of thrips date back to

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2304-517: The adult form. The first two instars , called larvae or nymphs, are like small wingless adults (often confused with springtails ) without genitalia; these feed on plant tissue. In the Terebrantia, the third and fourth instars, and in the Tubulifera also a fifth instar, are non-feeding resting stages similar to pupae : in these stages, the body's organs are reshaped, and wing-buds and genitalia are formed. The larvae of some species produce silk from

2376-445: The apices of which are moistened by a glandular secretion. The organs are adapted to apply the hairs closely to a smooth surface so that adhesion occurs through surface molecular forces. Insects control the ungues through muscle tension on a long tendon, the "retractor unguis" or "long tendon". In insect models of locomotion and motor control, such as Drosophila ( Diptera ), locusts ( Acrididae ), or stick insects ( Phasmatodea ),

2448-400: The bark. In Casuarina in the same country, some species have invaded stems, creating long-lasting woody galls. While poorly documented, chemical communication is believed to be important to the group. Anal secretions are produced in the hindgut, and released along the posterior setae as predator deterrents In Australia, aggregations of male common blossom thrips have been observed on

2520-494: The chloroplasts harvested from the outer layer of plant epidermal and mesophyll cells. They prefer tender parts of the plant, such as buds, flowers and new leaves. Besides feeding on plant tissues, the common blossom thrips feeds on pollen grains and on the eggs of mites. When the larva supplements its diet in this way, its development time and mortality is reduced, and adult females that consume mite eggs increase their fecundity and longevity. Some flower-feeding thrips pollinate

2592-482: The cladogram. Melanthripidae other Terebrantia Phlaeothripidae The following families are (2013) recognized: The identification of thrips to species is challenging as types are maintained as slide preparations of varying quality over time. There is also considerable variability leading to many species being misidentified. Molecular sequence based approaches have increasingly been applied to their identification. Thrips are believed to have descended from

2664-518: The coxa has two lobes where it articulates with the pleuron. The posterior lobe is the meron which is usually the larger part of the coxa. A meron is well developed in Periplaneta, the Isoptera, Neuroptera and Lepidoptera. The trochanter articulates with the coxa but usually is attached rigidly to the femur. In some insects, its appearance may be confusing; for example it has two subsegments in

2736-437: The effectiveness of new pesticides and methods. Due to their small sizes and high rates of reproduction, thrips are difficult to control using classical biological control . Suitable predators must be small and slender enough to penetrate the crevices where thrips hide while feeding, and they must also prey extensively on eggs and larvae to be effective. Only two families of parasitoid Hymenoptera parasitize eggs and larvae,

2808-547: The expansion of tissues causing distortion to leaf blades. More complex examples cause rosettes, pouches and horns. Most of these species occur in the tropics and sub-tropics, and the structures of the galls are diagnostic of the species involved. A radiation of thrips species seems to have taken place on Acacia trees in Australia; some of these species cause galls in the petioles , sometimes fixing two leaf stalks together, while other species live in every available crevice in

2880-511: The first pair may be enlarged. Insects and their relatives are hexapods, having six legs, connected to the thorax , each with five components. In order from the body they are the coxa, trochanter, femur, tibia, and tarsus. Each is a single segment, except the tarsus which can be from three to seven segments, each referred to as a tarsomere . Except in species in which legs have been lost or become vestigial through evolutionary adaptation, adult insects have six legs, one pair attached to each of

2952-475: The flexor muscle of the ungues. In the Neoptera , the parempodia are a symmetrical pair of structures arising from the outside (distal) surface of the unguitractor plate between the claws. It is present in many Hemiptera and almost all Heteroptera . Usually, the parempodia are bristly (setiform), but in a few species they are fleshy. Sometimes the parempodia are reduced in size so as to almost disappear. Above

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3024-581: The flowers they are feeding on, and some authors suspect that they may have been among the first insects to evolve a pollinating relationship with their host plants. Amber fossils of Gymnopollisthrips from the Early Cretaceous show them to be coated in Cycadopites -like pollen. Scirtothrips dorsalis carries pollen of commercially important chili peppers . Darwin found that thrips could not be kept out by any netting when he conducted experiments by keeping away larger pollinators. Thrips setipennis

3096-555: The group was published in 1895 by Heinrich Uzel , who is regarded by Fedor et al. as the father of Thysanoptera studies. The generic and English name thrips is a direct transliteration of the Ancient Greek word θρίψ , thrips , meaning " woodworm ". Like some other animal-names (such as sheep , deer , and moose ) in English the word "thrips" expresses both the singular and plural , so there may be many thrips or

3168-515: The head. Thrips have asymmetrical mouthparts unique to the group. Unlike the Hemiptera (true bugs), the right mandible of thrips is reduced and vestigial – and in some species completely absent. The left mandible is used briefly to cut into the food plant; saliva is injected and the maxillary stylets, which form a tube, are then inserted and the semi-digested food pumped from ruptured cells. This process leaves cells destroyed or collapsed, and

3240-441: The hosts including Mischocyttarus atramentarius , Mischocyttarus cassununga and Polistes versicolor are eaten by the thrips. Thrips, especially in the family Aeolothripidae , are also predators, and are considered beneficial in the management of pests like the codling moths . Most research has focused on thrips species that feed on economically significant crops. Some species are predatory, but most of them feed on pollen and

3312-416: The increasing globalization of trade and the growth of greenhouse agriculture, thrips, unsurprisingly, are among the fastest growing group of invasive species in the world. Examples include F. occidentalis , Thrips simplex , and Thrips palmi . Flower-feeding thrips are routinely attracted to bright floral colors (including white, blue, and especially yellow), and will land and attempt to feed. It

3384-567: The insect cleans its antennae by drawing them through. The ancestral tarsus was a single segment and in the extant Protura , Diplura and certain insect larvae the tarsus also is single-segmented. Most modern insects have tarsi divided into subsegments (tarsomeres), usually about five. The actual number varies with the taxon , which may be useful for diagnostic purposes. For example, the Pterogeniidae characteristically have 5-segmented fore- and mid-tarsi, but 4-segmented hind tarsi, whereas

3456-402: The insects' fringed wings. Thrips are small hemimetabolic insects with a distinctive cigar-shaped body plan . They are elongated with transversely constricted bodies. They range in size from 0.5 to 14 mm (0.02 to 0.55 in) in length for the larger predatory thrips, but most thrips are about 1 mm in length. Flight-capable thrips have two similar, strap-like pairs of wings with

3528-742: The larger males are busy fighting. In the Merothripidae and in the Aeolothripidae, males are again polymorphic with large and small forms, and probably also compete for mates, so the strategy may well be ancestral among the Thysanoptera. Many thrips form galls on plants when feeding or laying their eggs. Some of the gall-forming Phlaeothripidae , such as genera Kladothrips and Oncothrips , form eusocial groups similar to ant colonies, with reproductive queens and nonreproductive soldier castes. Most insects create lift by

3600-425: The leg segments articulates with the next segment in a hinge joint and may only bend in one plane. This means that a greater number of segments is required to achieve the same kinds of movements that are possible in vertebrate animals, which have rotational ball-and-socket joints at the base of the fore and hind limbs. The appendages of arthropods may be either biramous or uniramous . A uniramous limb comprises

3672-471: The legs of larval insects, particularly in the Endopterygota , vary more than in the adults. As mentioned, some have prolegs as well as "true" thoracic legs. Some have no externally visible legs at all (though they have internal rudiments that emerge as adult legs at the final ecdysis ). Examples include the maggots of flies or grubs of weevils . In contrast, the larvae of other Coleoptera , such as

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3744-470: The legs of most immature Ephemeroptera are adapted to scuttling beneath underwater stones and the like, whereas the adults have more gracile legs that are less of a burden during flight. Again, the young of the Coccoidea are called "crawlers" and they crawl around looking for a good place to feed, where they settle down and stay for life. Their later instars have no functional legs in most species. Among

3816-408: The long tendon courses through the tarsus and tibia before reaching the femur. Tension on the long tendon is controlled by two muscles, one in the femur and one in the tibia, which can operate differently depending on how the leg is bent. Tension on the long tendon controls the claw, but also bends the tarsus and likely affects its stiffness during walking. The typical thoracic leg of an adult insect

3888-476: The main exoskeleton of the insect. Such sclerites differ considerably between unrelated insects. The coxa is the proximal segment and functional base of the leg. It articulates with the pleuron and associated sclerites of its thoracic segment, and in some species it articulates with the edge of the sternite as well. The homologies of the various basal sclerites are open to debate. Some authorities suggest that they derive from an ancestral subcoxa. In many species,

3960-572: The naming system used in the other groups. They are: coxa, basis, ischium, merus, carpus, propodus, and dactylus. In some groups, some of the limb segments may be fused together. The claw ( chela ) of a lobster or crab is formed by the articulation of the dactylus against an outgrowth of the propodus. Crustacean limbs also differ in being biramous, whereas all other extant arthropods have uniramous limbs. Myriapods ( millipedes , centipedes and their relatives) have seven-segmented walking legs, comprising coxa, trochanter, prefemur, femur, tibia, tarsus, and

4032-438: The petals of Hibiscus rosa-sinensis and Gossypium hirsutum ; females were attracted to these groups so it seems likely that the males were producing pheromones . In the phlaeothripids that feed on fungi, males compete to protect and mate with females, and then defend the egg-mass. Males fight by flicking their rivals away with their abdomen, and may kill with their foretarsal teeth. Small males may sneak in to mate while

4104-595: The population late in the summer. Thrips can survive the winter as adults or through egg or pupal diapause . Thrips are haplodiploid with haploid males (from unfertilised eggs, as in Hymenoptera ) and diploid females capable of parthenogenesis (reproducing without fertilisation), many species using arrhenotoky , a few using thelytoky . In Pezothrips kellyanus females hatch from larger eggs than males, possibly because they are more likely to be fertilized. The sex-determining bacterial endosymbiont Wolbachia

4176-417: The possession of internal musculature. The exopodites can sometimes be missing in some crustacean groups ( amphipods and isopods ), and they are completely absent in insects. The legs of insects and myriapods are uniramous. In crustaceans, the first antennae are uniramous, but the second antennae are biramous, as are the legs in most species. For a time, possession of uniramous limbs was believed to be

4248-428: The primary pollinators of heathers in the family Ericaceae , and play a significant role in the pollination of pointleaf manzanita . Electron microscopy has shown thrips carrying pollen grains adhering to their backs, and their fringed wings are perfectly capable of allowing them to fly from plant to plant. Thrips can cause damage during feeding. This impact may fall across a broad selection of prey items, as there

4320-400: The right conditions, such as in greenhouses, invasive species can exponentially increase in population size and form large swarms because of a lack of natural predators coupled with their ability to reproduce asexually, making them destructive to crops. Their identification to species by standard morphological characteristics is often challenging. The first recorded mention of thrips dates from

4392-507: The same structure as modern adult insect legs, and there has been a great deal of debate as to whether they are homologous with them. Current evidence suggests that they are indeed homologous up to a very primitive stage in their embryological development, but that their emergence in modern insects was not homologous between the Lepidoptera and Symphyta . Such concepts are pervasive in current interpretations of phylogeny. In general,

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4464-410: The source of much argument. Some authors posit up to eleven segments per leg for the most recent common ancestor of extant arthropods but modern arthropods have eight or fewer. It has been argued that the ancestral leg need not have been so complex, and that other events, such as successive loss of function of a Hox -gene , could result in parallel gains of leg segments. In arthropods, each of

4536-525: The stiff-winged mechanism of insect flight with steady state aerodynamics ; this creates a leading edge vortex continuously as the wing moves. The feathery wings of thrips, however, generate lift by clap and fling , a mechanism discovered by the Danish zoologist Torkel Weis-Fogh in 1973. In the clap part of the cycle, the wings approach each other over the insect's back, creating a circulation of air which sets up vortices and generates useful forces on

4608-420: The suborder Tubulifera lay their eggs singly or in small groups on the outside surfaces of plants. Some thrips such as Elaphothrips tuberculatus are known to be facultatively ovoviviparous, retaining the eggs internally and giving birth to male offspring. Females in many species guard the eggs against cannibalism by other females as well as predators. Thrips are hemimetabolous , metamorphosing gradually to

4680-415: The terminal abdominal segment which is used to line the cell or form a cocoon within which they pupate. The adult stage can be reached in around 8–15 days; adults can live for around 45 days. Adults have both winged and wingless forms; in the grass thrips Anaphothrips obscurus , for example, the winged form makes up 90% of the population in spring (in temperate zones), while the wingless form makes up 98% of

4752-438: The three segments of the thorax. They have paired appendages on some other segments, in particular, mouthparts , antennae and cerci , all of which are derived from paired legs on each segment of some common ancestor . Some larval insects do however have extra walking legs on their abdominal segments; these extra legs are called prolegs . They are found most frequently on the larvae of moths and sawflies. Prolegs do not have

4824-418: The tibia, and the metatarsus (sometimes called basitarsus) between the tibia and the tarsus (sometimes called telotarsus), making a total of seven segments. The tarsus of spiders have claws at the end as well as a hook that helps with web-spinning. Spider legs can also serve sensory functions, with hairs that serve as touch receptors, as well as an organ on the tarsus that serves as a humidity receptor, known as

4896-427: The tips of plants to leap and catch air current. Wind-aided dispersal of species has been recorded over 1600 km of sea between Australia and South Island of New Zealand. It has been suggested that some bird species may also be involved in the dispersal of thrips. Thrips are picked up along with grass in the nests of birds and can be transported by the birds. A hazard of flight for very small insects such as thrips

4968-497: The unguitractor plate, the pretarsus expands forward into a median lobe, the arolium . Webspinners ( Embioptera ) have an enlarged basal tarsomere on each of the front legs, containing the silk -producing glands. Under their pretarsi, members of the Diptera generally have paired lobes or pulvilli, meaning "little cushions". There is a single pulvillus below each unguis. The pulvilli often have an arolium between them or otherwise

5040-484: The wings. Thrips are a functionally diverse group; many of the known species are fungivorous . A small proportion of the species are serious pests of commercially important crops. Some of these serve as vectors for over 20 viruses that cause plant disease , especially the Tospoviruses . Many flower-dwelling species bring benefits as pollinators, with some predatory thrips feeding on small insects or mites . In

5112-419: The wings. The leading edges of the wings touch, and the wings rotate around their leading edges, bringing them together in the "clap". The wings close, expelling air from between them, giving more useful thrust. The wings rotate around their trailing edges to begin the "fling", creating useful forces. The leading edges move apart, making air rush in between them and setting up new vortices, generating more force on

5184-516: The wings. The trailing edge vortices, however, cancel each other out with opposing flows. Weis-Fogh suggested that this cancellation might help the circulation of air to grow more rapidly, by shutting down the Wagner effect which would otherwise counteract the growth of the circulation. Apart from active flight, thrips, even wingless ones, can also be picked up by winds and transferred long distances. During warm and humid weather, adults may climb to

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