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118-410: Physically, some insects move their flight muscles directly, others indirectly. In insects with direct flight, the wing muscles directly attach to the wing base, so that a small downward movement of the wing base lifts the wing itself upward. Those insects with indirect flight have muscles that attach to and deform the thorax, causing the wings to move as well. The wings are present in only one sex (often

236-498: A " stridulation ") by rubbing their wings against each other or their legs, the wings or legs containing rows of corrugated bumps. The tympanum , or ear , is located in the front tibia in crickets, mole crickets , and bush crickets or katydids, and on the first abdominal segment in the grasshoppers and locusts. These organisms use vibrations to locate other individuals. Grasshoppers and other orthopterans are able to fold their wings (i.e. they are members of Neoptera ). The name

354-467: A direct crustacean ancestor and shared genetic mechanisms of limb development. Other theories of the origin of insect wings are the paranotal lobe theory, the gill theory and the dual theory of insect wing evolution. These theories postulate that wings either developed from paranotal lobes, extensions of the thoracic terga ; that they are modifications of movable abdominal gills as found on aquatic naiads of mayflies ; or that insect wings arose from

472-1230: A division into two suborders – Caelifera and Ensifera – occurring 256  million years ago . The Orthoptera are divided into two suborders, Caelifera and Ensifera , that have been shown to be monophyletic . A recent comprehensive phylogeny based on analyses of data from transcriptomes and mitochondrial genomes found the following relationships within Orthoptera. Gryllotalpoidea (mole crickets and ant crickets) Grylloidea ("true crickets", scaly crickets, wood crickets, etc) [REDACTED] Rhaphidophoroidea (cave crickets, camel crickets, spider crickets and sand treaders) [REDACTED] Schizodactyloidea (dune crickets) [REDACTED] Stenopelmatoidea (Jerusalem crickets, king crickets, leaf-rolling crickets and Cooloola monsters) Hagloidea (grigs) Tettigonioidea (katydids or bush crickets) [REDACTED] Tridactyloidea [REDACTED] Tetrigoidea [REDACTED] Eumastacoidea [REDACTED] Proscopioidea Tanaoceroidea Trigonopterygoidea Pneumoroidea [REDACTED] Pyrgomorphoidea [REDACTED] Acridoidea [REDACTED] Taxonomists classify members of

590-446: A given male and female belong to the same species, unless they are captured while mating. In some species, the male carries the smaller female aloft while mating, which is also seen in the related family Thynnidae . As is the case for all aculeates , only female mutillids are capable of inflicting a sting. The stinger is a modified female organ called an ovipositor , which is unusually long and maneuverable in mutillids. In both sexes,

708-589: A known pest in soybean fields and will likely feed on these crops once preferred food sources have become scarce. Most orthopterans are edible, making up 13% of all insects including some 80 species of grasshoppers being regularly consumed worldwide. In Madagascar and Oaxaca , grasshoppers and locusts are usually collected early in the morning when it is cooler as the orthopterans are less mobile due to being cold-blooded . In Thailand, house crickets are commonly reared and eaten; as of 2012, around 20,000 cricket farmers had farms in 53 of their 76 provinces . In

826-444: A large trachea, a cross-section of which is shown in, which represents sections of these parts of the first, second, third and fourth instars respectively. At the same time the tracheoles uncoil, and extend in bundles in the forming vein-cavities of the wing-bud. At the molt that marks the beginning of the pupal stadium stage, they become functional. At the same time, the larval tracheoles degenerate; their function having been replaced by

944-474: A local predator of velvet ants in the black-headed Timulla and tropical mimicry rings. Male mutillids fly in search of females; after mating, the female enters a host insect nest, typically a ground-nesting bee or wasp burrow, and deposits one egg near each larva or pupa . Only a few species are known to parasitize other types of hosts; exceptions include the European velvet ant, Mutilla europaea , one of

1062-431: A membranous basal area, but the articular membrane contains a number of small articular sclerites, collectively known as the pteralia. The pteralia include an anterior humeral plate at the base of the costal vein, a group of axillaries (Ax) associated with the subcostal, radial, and vannal veins, and two less definite median plates (m, m') at the base of the mediocubital area. The axillaries are specifically developed only in

1180-461: A more primitive flight mechanism does not mean they are less able fliers; they are, in certain ways, more agile than anything that has evolved afterward. While the development of wings in insects is clearly defined in those who are members of Endopterygota , which undergo complete metamorphosis ; in these species, the wing develops while in the pupal stage of the insects life cycle. However, insects that undergo incomplete metamorphosis do not have

1298-412: A plethora of impressive defensive strategies in prey species to improve the likelihood of escape. Velvet ants avoid predation using the following defense mechanisms: a venomous sting (if female), aposematic coloration , a stridulatory organ in their abdomen, an alarm secretion from their mandibular gland, and a durable exoskeleton. This array of defenses has contributed to the velvet ants being attributed

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1416-415: A posterior concave branch. Thus the costa and subcosta are regarded as convex and concave branches of a primary first vein, Rs is the concave branch of the radius, posterior media the concave branch of the media, Cu1 and Cu2 are respectively convex and concave, while the primitive Postcubitus and the first vannal have each an anterior convex branch and a posterior concave branch. The convex or concave nature of

1534-407: A pupal stage, therefore they must have a different wing morphogenesis . Insects such as those that are hemimetabolic have wings that start out as buds, which are found underneath the exoskeleton, and do not become exposed until the last instar of the nymph . The first indication of the wing buds is of a thickening of the hypodermis, which can be observed in insect species as early the embryo, and in

1652-404: A radically different coloration from the adults. Through successive moults , the nymphs develop wings until their final moult into a mature adult with fully developed wings. The number of moults varies between species; growth is also very variable and may take a few weeks to some months depending on food availability and weather conditions. This order evolved 300  million years ago with

1770-689: A role in something else, such as mating or protection . Some insects, occupying the biological niches that they do, need to be incredibly maneuverable. They must find their food in tight spaces and be capable of escaping larger predators – or they may themselves be predators, and need to capture prey. Their maneuverability, from an aerodynamic viewpoint, is provided by high lift and thrust forces. Typical insect fliers can attain lift forces up to three times their weight and horizontal thrust forces up to five times their weight. There are two substantially different insect flight mechanisms, and each has its own advantages and disadvantages – just because odonates have

1888-473: A single anal vein. Distally the vannal veins are either simple or branched. Jugal Veins (J) of the jugal lobe of the wing is often occupied by a network of irregular veins, or it may be entirely membranous; but sometimes it contains one or two distinct small veins, the first jugal vein, or vena arcuata, and the second jugal vein, or vena cardinalis (2J). All the veins of the wing are subject to secondary forking and to union by cross-veins. In some orders of insects

2006-402: A single day. Individuals gather in large groups called swarms, these swarms can range up to 80 million individuals that stretch 460 square miles. Grasshoppers can cause major agricultural damage but not to the documented extent as locust historically have. These insects mainly feed on weeds and grasses, however, during times of drought and high population density they will feed on crops. They are

2124-411: A structure called a stridulitrum on the metasoma is used to produce a squeaking or chirping sound when alarmed. Both sexes of mutillids also bear hair-lined grooves on the side of the metasoma called felt lines. Only two other vespoid families ( Bradynobaenidae and Chyphotidae ) have felt lines, but the females of these families have a distinct pronotum , with a transverse suture separating it from

2242-419: A velvet ant it was exposed to. In both cases the velvet ants were exhibiting rapid lateral and vertical movements to ward off an attack. Once the attack occurred the velvet ants would immediately sting the lizards. This sting resulted in the dropping of the ants in both cases and avoidance for the remainder of the trial. The side-blotched lizard was found dead in its tank 24 hours later. The side-blotched lizard

2360-401: A vortex over each wing. This bound vortex then moves across the wing and, in the clap, acts as the starting vortex for the other wing. Circulation and lift are increased, at the price of wear and tear on the wings. Many insects can hover by beating their wings rapidly, requiring sideways stabilization as well as lift. A few insects use gliding flight, without the use of thrust. Sometime in

2478-454: A wingless sister taxa to the winged insects. The earliest fliers were similar to dragonflies with two sets of wings, direct flight muscles, and no ability to fold their wings over their abdomens . Most insects today, which evolved from those first fliers, have simplified to either one pair of wings or two pairs functioning as a single pair and using a system of indirect flight muscles. Natural selection has played an enormous role in refining

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2596-425: Is a natural predator of velvet ants, while the whiptail is not. The aposematic coloration of velvet ants often corresponds to a specific Müllerian mimicry ring consisting of dozens of species. This offers protection because many local predators have learned to avoid prey with this same coloration. To test the aposematic coloration on birds, mealworms were painted to resemble a velvet ant. During these trials, none of

2714-526: Is a strictly aerobic tissue. Per unit protein it consumes fuel and oxygen at rates taking place in a very concentrated and highly organized tissue so that the steady-state rates per unit volume represent an absolute record in biology. The fuel and oxygen rich blood is carried to the muscles through diffusion occurring in large amounts, in order to maintain the high level of energy used during flight. Many wing muscles are large and may be as large as 10 mm in length and 2 mm in width. Moreover, in some Diptera

2832-411: Is at the leading edge, which is associated at its base with the humeral plate. The trachea of the costal vein is perhaps a branch of the subcostal trachea. Located after the costa is the third vein, the subcosta, which branches into two separate veins: the anterior and posterior. The base of the subcosta is associated with the distal end of the neck of the first axillary (see section below). The fourth vein

2950-545: Is bright scarlet or orange, but may also be black, white, silver, or gold. Their bright colors serve as aposematic signals. They are known for their extremely painful stings , (the sting of the species Dasymutilla klugii rated a 3 on the Schmidt pain index and lasts up to 30 minutes ), and has resulted in the common name "cow killer" or "cow ant" being applied to the species Dasymutilla occidentalis . However, mutillids are not aggressive and sting only in defense. In addition,

3068-536: Is derived from the Greek ὀρθός orthos meaning "straight" and πτερόν pteron meaning "wing". Orthopterans have a generally cylindrical body, with elongated hindlegs and musculature adapted for jumping . They have mandibulate mouthparts for biting and chewing and large compound eyes , and may or may not have ocelli , depending on the species. The antennae have multiple joints and filiform type, and are of variable length. The first and third segments on

3186-428: Is not until the butterfly is in its pupal stage that the wing-bud becomes exposed, and shortly after eclosion , the wing begins to expand and form its definitive shape. The development of tracheation of the wings begin before the wing histoblast form, as it is important to note that they develop near a large trachea . During the fourth instar, cells from the epithelium of this trachea become greatly enlarged extend into

3304-438: Is the anterior hinge plate of the wing base. Its anterior part is supported on the anterior notal wing process of the tergum (ANP); its posterior part articulates with the tergal margin. The anterior end of the sclerite is generally produced as a slender arm, the apex of which (e) is always associated with the base of the subcostal vein (Sc), though it is not united with the latter. The body of the sclerite articulates laterally with

3422-413: Is the defining feature ( synapomorphy ) for the infraclass Neoptera . There are two basic aerodynamic models of insect flight. Most insects use a method that creates a spiralling leading edge vortex . Some very small insects use the fling and clap or Weis-Fogh mechanism in which the wings clap together above the insect's body and then fling apart. As they fling open, the air gets sucked in and creates

3540-431: Is the radius (R), which is branched into five separate veins. The radius is generally the strongest vein of the wing. Toward the middle of the wing, it forks into a first undivided branch (R1) and a second branch, called the radial sector (Ra), which subdivides dichotomously into four distal branches (R2, R3, R4, R5). Basally, the radius is flexibly united with the anterior end of the second axillary (2Ax). The fifth vein of

3658-599: Is unusually tough (to the point that some entomologists have reported difficulty piercing them with steel pins when attempting to mount them for display in cabinets). This characteristic allows them to successfully invade the nests of their prey and also helps them retain moisture. Mutillids exhibit extreme sexual dimorphism . As in some related families in the Vespoidea , males have wings, but females are wingless. The males and females are so distinct in their morphology that entomologists often find it very hard to determine whether

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3776-420: Is usually a small plate intervening between the third axillary and the posterior notal wing process and is probably a detached piece of the latter. The median plates (m, m') are also sclerites that are not so definitely differentiated as specific plates as are the three principal axillaries, but nevertheless they are important elements of the flexor apparatus. They lie in the median area of the wing base distal to

3894-543: The Carboniferous Period , some 350 million years ago, when there were only two major land masses, insects began flying. How and why insect wings developed, however, is not well understood, largely due to the scarcity of appropriate fossils from the period of their development in the Lower Carboniferous. Three main theories on the origins of insect flight are that wings developed from paranotal lobes, extensions of

4012-529: The aphids , migratory phases of locusts and polymorphic butterflies . At rest, the wings may be held flat, or folded a number of times along specific patterns; most typically, it is the hindwings which are folded, but in a few groups such as the vespid wasps , it is the forewings. The evolutionary origin of the insect wing is debated. During the 19th century, the question of insect wing evolution originally rested on two main positions. One position postulated insect wings evolved from pre-existing structures, while

4130-427: The grasshoppers , locusts , and crickets , including closely related insects, such as the bush crickets or katydids and wētā . The order is subdivided into two suborders: Caelifera – grasshoppers, locusts, and close relatives; and Ensifera – crickets and close relatives. More than 20,000 species are distributed worldwide. The insects in the order have incomplete metamorphosis , and produce sound (known as

4248-410: The histoblast become more prominent, which now form a pocket-like structure. As of the third and fourth instars, the histoblast become more elongated. This greatly extended and evaginated, or protruding, part is what becomes the wing. By the close of the last instar, or fifth, the wing is pushed out of the wing-pocket, although continues to lie under the old larval cuticle while in its prepupal stage. It

4366-498: The mesonotum ; in female mutillids, these two thoracic segments are completely fused. Members of the family Myrmosidae , formerly classified as a subfamily of mutillids, also have a distinct pronotum in females, but lack felt lines in both sexes. Adult mutillids feed on nectar . Although some species are strictly nocturnal, females are often active during the day. Females of Tricholabiodes thisbe are sometimes active up to two hours before sunset. Guido Nonveiller (1963) hypothesized

4484-554: The thoracic terga ; that they are modifications of movable abdominal gills as found on aquatic naiads of mayflies ; or that they developed from thoracic protrusions used as radiators . Fossils from the Devonian (400 million years ago) are all wingless, but by the Carboniferous (320 million years ago), more than 10 different genera of insects had fully functional wings. There is little preservation of transitional forms between

4602-421: The thorax are larger, while the second segment is much smaller. They have two pairs of wings , which are held overlapping the abdomen at rest. The forewings, or tegmina , are narrower than the hindwings and hardened at the base, while the hindwings are membranous, with straight veins and numerous cross-veins. At rest, the hindwings are held folded fan-like under the forewings. The final two to three segments of

4720-469: The Caelifera and Ensifera into infraorders and superfamilies as follows: Several species of Orthoptera are considered pests of crops and rangelands or seeking warmth in homes by humans. The two groups of Orthoptera that cause the most damage are grasshoppers and locusts . Locust are historically known for wiping out fields of crops in a day. Locust have the ability to eat up to their own body weight in

4838-519: The Ephemerida, according to present interpretations of the wing venation, both branches of the media are retained, while in Odonata the persisting media is the primitive anterior branch. The stem of the media is often united with the radius, but when it occurs as a distinct vein its base is associated with the distal median plate (m') or is continuously sclerotized with the latter. The cubitus, the sixth vein of

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4956-470: The Mutillidae are generally stenothermic and thermophilic ; they may not avoid light, but rather are active during temperatures that usually occur only after sunset. Predation is one of the strongest forces natural selection uses to drive the evolution of an organism's morphology, physiology, and behavior. During this coevolution, the prey either being consumed by the predator or escaping has resulted in

5074-462: The Odonata ( dragonflies and damselflies ) have the flight muscles attached directly to their wings; the wings can beat no faster than the rate at which nerves can send impulses to command the muscles to beat. All other living winged insects fly using a different mechanism, involving indirect flight muscles which cause the thorax to vibrate; the wings can beat faster than the rate at which the muscles receive nerve impulses. This mechanism evolved once, and

5192-461: The Permian and all are amphibious . Their prototypes are the oldest winged fossils, go back to the Devonian , and are different from other wings in every way. Their prototypes may have had the beginnings of many modern attributes even by late Carboniferous and it is possible that they even captured small vertebrates, for some species had a wing span of 71 cm. The earliest beetle-like species during

5310-522: The Permian had pointed, leather like forewings with cells and pits. Hemiptera , or true bugs had appeared in the form of Arctiniscytina and Paraknightia having forewings with unusual venation, possibly diverging from Blattoptera . A single large wing from a species of Diptera in the Triassic (10 mm instead of usual 2–6 mm) was found in Australia (Mt. Crosby).This family Tilliardipteridae, despite

5428-461: The Postcubitus is always associated proximally with the cubitus and is never intimately connected with the flexor sclerite (3Ax) of the wing base. In Neuroptera, Mecoptera, and Trichoptera the postcubitus may be more closely associated with the vannal veins, but its base is always free from the latter. The postcubitus is usually unbranched; it is primitively two branched. The vannal veins (lV to nV) are

5546-438: The abdomen are reduced, and have single-segmented cerci . Orthopterans have a paurometabolous lifecycle or incomplete metamorphosis . The use of sound is generally crucial in courtship, and most species have distinct songs. Most grasshoppers lay their eggs in the ground or on vegetation. The eggs hatch and the young nymphs resemble adults, but lack wings and at this stage are often called 'hoppers'. They may often also have

5664-432: The abdomen is contracted. This mechanism is an auditory cue warning predators that are about to attack to stay away. In one experiment, every time a shrew got within 1 meter of a velvet ant, the velvet ant would begin stridulating. Stridulations became more frequent as the predator moved closer to the velvet ant, and the shrew never attempted to attack the velvet ant. However, different scenarios with shrews have shown that

5782-634: The actual toxicity of their venom is much lower than that of honey bees or harvester ants . Unlike true ants , they are solitary, and lack complex social systems. Mutillidae can be found worldwide with about 230 genera or subgenera and around 8,000 species worldwide. Over 400 species occur in the North American Southwest. North American Mutillidae have eight phenotypically distinct and geographically limited Müllerian mimicry rings (Desert, Eastern, Madrean, Texan, Red-headed Timulla , Black-headed Timulla , Tropical, and Western) making up one of

5900-414: The aerodynamic efficiency of flight by joining the forewing and hindwing into one bigger wing. The most common coupling mechanism (e.g., Hymenoptera and Trichoptera ) is a row of small hooks on the forward margin of the hindwing, or " hamuli ", which lock onto the forewing, keeping them held together (hamulate coupling). In some other insect species (e.g., Mecoptera , Lepidoptera , and some Trichoptera )

6018-415: The anal area can be folded like a fan. There are about four different fields found on the insect wings: Most veins and crossveins occur in the anterior area of the remigium , which is responsible for most of the flight, powered by the thoracic muscles. The posterior portion of the remigium is sometimes called the clavus ; the two other posterior fields are the anal and jugal ares . When the vannal fold has

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6136-401: The anal area of the wing membrane behind the single vannal vein sets off a proximal alar lobe distal to the outer squama of the alula. The various movements of the wings, especially in insects that flex the wings horizontally over the back when at rest, demand a more complicated articular structure at the wing base than a mere hinge of the wing with the body. Each wing is attached to the body by

6254-410: The anal veins that are immediately associated with the third axillary, and which are directly affected by the movement of this sclerite that brings about the flexion of the wings. In number the vannal veins vary. from 1 to 12, according to the expansion of the vannal area of the wing. The vannal tracheae usually arise from a common tracheal stem in nymphal insects, and the veins are regarded as branches of

6372-500: The archedictyon contained 6–8 longitudinal veins. These veins (and their branches) are named according to a system devised by John Comstock and George Needham—the Comstock–Needham system : The costa (C) is the leading marginal vein on most insects. Sometimes, there is a small vein above the costa called the precosta, although in almost all extant insects, the precosta is fused with the costa. The costa rarely ever branches because it

6490-407: The articular membrane often forms an ample lobe between the wing and the body, and its margin is generally thickened and corrugated, giving the appearance of a ligament, the so-called axillary cord, continuous mesally with the posterior marginal scutellar fold of the tergal plate bearing the wing. The articular sclerites, or pteralia, of the wing base of the wing-flexing insects and their relations to

6608-433: The axillary sclerites has in general the form of a scalene triangle. The base of the triangle (a-b) is the hinge of the wing with the body; the apex (c) is the distal end of the third axillary sclerite; the longer side is anterior to the apex. The point d on the anterior side of the triangle marks the articulation of the radial vein with the second axillary sclerite. The line between d and c is the plica basalis (bf), or fold of

6726-525: The base of the forewings of Tettigonioidea and Acridoidea (katydids and grasshoppers respectively). The archedictyon is the name given to a hypothetical scheme of wing venation proposed for the very first winged insect. It is based on a combination of speculation and fossil data. Since all winged insects are believed to have evolved from a common ancestor, the archedictyon represents the "template" that has been modified (and streamlined) by natural selection for 200 million years. According to current dogma,

6844-416: The base of the mediocubital field of the wing. When the veins of this region are distinct at their bases, they are associated with the outer median plate. The muscles that control flight in insects can take up to 10% to 30% of the total body mass. The muscles that control flight vary with the two types of flight found in insects: indirect and direct. Insects that use first, indirect, have the muscles attach to

6962-429: The base of the wing. The subalar and basilar muscles have ligament attachments to the subalar and basilar sclerites. Here resilin, a highly elastic material, forms the ligaments connecting flight muscles to the wing apparatus. In more derived orders of insects, such as Diptera (flies) and Hymenoptera (wasp), the indirect muscles occupy the greatest volume of the pterothorax and function as the primary source of power for

7080-502: The body and the wing veins, shown diagrammatically, are as follows: The humeral plate is usually a small sclerite on the anterior margin of the wing base, movable and articulated with the base of the costal vein. Odonata have their humeral plate greatly enlarged, with two muscles arising from the episternum inserted into the Humeral plates and two from the edge of the epimeron inserted into the axillary plate. The first axillary sclerite (lAx)

7198-416: The cavity of the wing bud, with each cell having developed a closely coiled tracheole . Each trachcole is of unicellular origin, and is at first intracellular in position; while tracheae are of multicellular origin and the lumen of each is intercellular in position. The development of tracheoles, each coiled within a single cell of the epithelium of a trachea, and the subsequent opening of communication between

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7316-454: The cicada the vannal fold lies immediately behind the first vannal vein (lV). These small variations in the actual position of the vannal fold, however, do not affect the unity of action of the vannal veins, controlled by the flexor sclerite (3Ax), in the flexion of the wing. In the hindwings of most Orthoptera a secondary vena dividens forms a rib in the vannal fold. The vannus is usually triangular in shape, and its veins typically spread out from

7434-407: The claval furrow and jugal fold are probably homologous in different species, the vannal fold varies in position in different taxa. Folding is produced by a muscle arising on the pleuron and inserted into the third axillary sclerite in such a way that, when it contracts, the sclerite pivots about its points of articulation with the posterior notal process and the second axillary sclerite. As a result,

7552-403: The cross-veins are so numerous that the whole venational pattern becomes a close network of branching veins and cross-veins. Ordinarily, however, there is a definite number of cross-veins having specific locations. The more constant cross-veins are the humeral cross-vein (h) between costa and subcosta, the radial cross-vein (r) between R and the first fork of Rs, the sectorial cross-vein (s) between

7670-429: The distal arm of the third axillary sclerite rotates upwards and inwards, so that finally its position is completely reversed. The anal veins are articulated with this sclerite in such a way that when it moves they are carried with it and become flexed over the back of the insect. Activity of the same muscle in flight affects the power output of the wing and so it is also important in flight control. In orthopteroid insects,

7788-407: The earliest stages of the life cycle. During the development of morphological features while in the embryo, or embryogenesis , a cluster of cells grow underneath the ectoderm which later in development, after the lateral ectoderm has grown dorsally to form wind imaginal disc. An example of wing bud development in the larvae, can be seen in those of White butterflies ( Pieris ). In the second instar

7906-484: The elasticity of the cuticle causes the vannal area of the wing to fold along the veins. Consequently, energy is expended in unfolding this region when the wings are moved to the flight position. In general, wing extension probably results from the contraction of muscles attached to the basilar sclerite or, in some insects, to the subalar sclerite. Two groups of relatively large insects, the Ephemeroptera ( mayflies ) and

8024-409: The family Mutillidae contained one subfamily that was unrelated to the remainder, and this subfamily was removed to form a separate family Myrmosidae . Orthoptera Suborder Ensifera Suborder Caelifera Orthoptera (from Ancient Greek ὀρθός ( orthós )  'straight' and πτερά ( pterá )  'wings') is an order of insects that comprises

8142-428: The fibres are of giant dimensions. For instance, in the very active Rutilia , the cross-section is 1800 μm long and more than 500 μm wide. The transport of fuel and oxygen from the surroundings to the sites of consumption and the reverse transport of carbon dioxide therefore represent a challenge to the biologist both in relation to transport in the liquid phase and in the intricate system of air tubes, i.e. in

8260-422: The flexion lines. Though fold lines may be transverse, as in the hindwings of beetles and earwigs, they are normally radial to the base of the wing, allowing adjacent sections of a wing to be folded over or under each other. The commonest fold line is the jugal fold, situated just behind the third anal vein, although, most Neoptera have a jugal fold just behind vein 3A on the forewings. It is sometimes also present on

8378-401: The fold-lines is often blurred, as fold-lines may permit some flexibility or vice versa. Two constants that are found in nearly all insect wings are the claval (a flexion-line) and jugal folds (or fold line); forming variable and unsatisfactory boundaries. Wing foldings can be very complicated, with transverse folding occurring in the hindwings of Dermaptera and Coleoptera , and in some insects

8496-431: The fracture of a velvet ant's exoskeleton, a total of 4 times resulted in the death of that velvet ant within 24 hours. Aside from protection from predators, the exoskeleton also helps control moisture. Due to these strong defense mechanisms, local predators generally avoid the velvet ants, so it has been difficult to determine their predators. One study found tropical and subtropical iguanian lizards ( Dactyloidae ) to be

8614-450: The fulcral wing process of the pleuron. The second axillary, therefore, is the pivotal sclerite of the wing base, and it specifically manipulates the radial vein. The third axillary sclerite (3Ax) lies in the posterior part of the articular region of the wing. Its form is highly variable and often irregular, but the third axillary is the sclerite on which is inserted the flexor muscle of the wing (D). Mesally it articulates anteriorly (f) with

8732-419: The fusion of pre-existing endite and exite structures each with pre-existing articulation and tracheation. Each of the wings consists of a thin membrane supported by a system of veins. The membrane is formed by two layers of integument closely apposed, while the veins are formed where the two layers remain separate; sometimes the lower cuticle is thicker and more heavily sclerotized under a vein. Within each of

8850-418: The hindwings. Where the anal area of the hindwing is large, as in Orthoptera and Blattodea, the whole of this part may be folded under the anterior part of the wing along a vannal fold a little posterior to the claval furrow. In addition, in Orthoptera and Blattodea, the anal area is folded like a fan along the veins, the anal veins being convex, at the crests of the folds, and the accessory veins concave. Whereas

8968-452: The jugal area of the forewing is developed as a free lobe, it projects beneath the humeral angle of the hindwing and thus serves to yoke the two wings together. In the Jugatae group of Lepidoptera it bears a long finger-like lobe. The jugal region was termed the neala ("new wing") because it is evidently a secondary and recently developed part of the wing. The axillary region is region containing

9086-399: The jugal lobe of other insects (A, D); the larger inner squama (d) arises from the posterior scutellar margin of the tergum of the wing-bearing segment and forms a protective, hoodlike canopy over the haltere. In the flexed wing the outer squama of the alula is turned upside down above the inner squama, the latter not being affected by the movement of the wing. In many Diptera a deep incision of

9204-470: The jugal lobe of the forewing covers a portion of the hindwing (jugal coupling), or the margins of the forewing and hindwing overlap broadly (amplexiform coupling), or the hindwing bristles, or frenulum, hook under the retaining structure or retinaculum on the forewing. When at rest, the wings are held over the back in most insects, which may involve longitudinal folding of the wing membrane and sometimes also transverse folding. Folding may sometimes occur along

9322-416: The largest Müllerian mimicry complexes on the planet. These mimicry rings are the result of repeated convergent evolution of aposematic traits between co-occurring velvet ant species, rather than shared phylogenetic history. Through the evolution of aposematic traits in velvet ant species in the same ring, local predators have learned to avoid these well-defended wasps. The exoskeleton of all velvet ants

9440-472: The main stem of the cubitus is associated with the distal median plate (m') of the wing base. Postcubitus (Pcu) is the first anal of the Comstock–Needham system. The postcubitus, however, has the status of an independent wing vein and should be recognized as such. In nymphal wings, its trachea arises between the cubital trachea and the group of vannal tracheae. In the mature wings of more generalized insect

9558-420: The major veins there is a nerve and a trachea , and, since the cavities of the veins are connected with the hemocoel , hemolymph can flow into the wings. As the wing develops, the dorsal and ventral integumental layers become closely apposed over most of their area forming the wing membrane. The remaining areas form channels, the future veins, in which the nerves and tracheae may occur. The cuticle surrounding

9676-410: The male) in some groups such as velvet ants and Strepsiptera , or are selectively lost in "workers" of social insects such as ants and termites . Rarely, the female is winged but the male not, as in fig wasps . In some cases, wings are produced only at particular times in the life cycle, such as in the dispersal phase of aphids . Wing structure and colouration often vary with morphs , such as in

9794-495: The numerous 'tipuloid' features, should be included in Psychodomorpha sensu Hennig on account of loss of the convex distal 1A reaching wing margin and formation of the anal loop. Suggestions have been made that wings may have evolved initially for sailing on the surface of water as seen in some stoneflies . An alternative idea is that it derives from directed aerial gliding descent—a preflight phenomena found in some apterygote ,

9912-471: The only species that attacks social bees (e.g., Bombus ), and the genus Pappognatha , whose hosts are tree-dwelling orchid bees . The mutillid larvae then develop as idiobiont ectoparasitoids , eventually killing their immobile larval/pupal hosts within a week or two. Velvet ants exhibit haplodiploid sex determination, as do other members of the superfamily Vespoidea . Recent classifications of Vespoidea sensu lato (beginning in 2008) concluded that

10030-448: The opposite position between the two branches. A concave vein will fork into two concave veins (with the interpolated vein being convex) and the regular alteration of the veins is preserved. The veins of the wing appear to fall into an undulating pattern according to whether they have a tendency to fold up or down when the wing is relaxed. The basal shafts of the veins are convex, but each vein forks distally into an anterior convex branch and

10148-434: The origin of insect wings. Among these include: gills, respiratory appendages of legs, and lateral (paranotal) and posterolateral projections of the thorax to name a few. According to more current literature, possible candidates include gill-like structures, the paranotal lobe, and the crustacean tergal plate. The latter is based on recent insect genetic research which indicates that insects are pan-crustacean arthropods with

10266-433: The painfulness of the sting of Dasymutilla klugii outscored 58 other species of stinging insects tested; the only species this researcher rated as having a more painful sting were Paraponera clavata (bullet ant), Synoeca septentrionalis (warrior wasp), and Pepsis and Hemipepsis spp. ( tarantula hawks ). In an experimental setting, only two lizard species (one whiptail and one side-blotched lizard ) attacked

10384-441: The painted mealworms were consumed, while all the control mealworms were consumed immediately. However, the painted mealworms were attacked by the birds, but the birds immediately ceased the attack. These experiments provide evidence that the aposematic coloration of velvet ants causes their predators to hesitate, acting as a visual defense mechanism. The stridulatory organ that velvet ants possess produces an audible squeaking when

10502-399: The posterior end of the second axillary, and posteriorly (b) with the posterior wing process of the tergum (PNP), or with a small fourth axillary when the latter is present. Distally the third axillary is prolonged in a process which is always associated with the bases of the group of veins in the anal region of the wing here termed the vannal veins (V). The third axillary, therefore, is usually

10620-413: The posterior hinge plate of the wing base and is the active sclerite of the flexor mechanism, which directly manipulates the vannal veins. The contraction of the flexor muscle (D) revolves the third axillary on its mesal articulations (b, f) and thereby lifts its distal arm; this movement produces the flexion of the wing. The Fourth Axillary sclerite is not a constant element of the wing base. When present it

10738-418: The second and third axillaries and are separated from each other by an oblique line (bf) which forms a prominent convex fold during flexion of the wing. The proximal plate (m) is usually attached to the distal arm of the third axillary and perhaps should be regarded as a part of the latter. The distal plate (m') is less constantly present as a distinct sclerite and may be represented by a general sclerotization of

10856-432: The second axillary. The second axillary sclerite (2Ax) is more variable in form than the first axillary, but its mechanical relations are no less definite. It is obliquely hinged to the outer margin of the body of the first axillary, and the radial vein (R) is always flexibly attached to its anterior end (d). The second axillary presents both a dorsal and a ventral sclerotization in the wing base; its ventral surface rests upon

10974-637: The second century BCE in Ancient Greece , Diodorus Siculus is known to have called people from Ethiopia Acridophagi , meaning "eaters of locusts." In Judaism , the Orthoptera include the only insects considered kosher . The list of dietary laws in the book of Leviticus forbids all flying insects that walk, but makes an exception for certain locusts . The Torah states the only kosher flying insects with four walking legs have knees that extend above their feet so that they hop. With new research showing promise in locating alternative biofuel sources in

11092-451: The second proposed insect wings were entirely novel formations. The “novel” hypothesis suggested that insect wings did not form from pre-existing ancestral appendages but rather as outgrowths from the insect body wall. Long since, research on insect wing origins has built on the “pre-existing structures” position that was originally proposed in the 19th century. Recent literature has pointed to several ancestral structures as being important to

11210-453: The subcosta and part of the radius are present. Conversely, an increase in venation may occur by the branching of existing veins to produce accessory veins or by the development of additional, intercalary veins between the original ones, as in the wings of Orthoptera (grasshoppers and crickets). Large numbers of cross-veins are present in some insects, and they may form a reticulum as in the wings of Odonata (dragonflies and damselflies) and at

11328-452: The tergum instead of the wings, as the name suggests. As the muscles contract, the thoracic box becomes distorted, transferring the energy to the wing. There are two "bundles" of muscles, those that span parallel to the tergum, the dorsolongitudinals, and those that are attached to the tegum and extend to the sternum, the dorsoventrals. In direct muscle, the connection is directly from the pleuron (thoracic wall) to individual sclerites located at

11446-477: The third axillary like the ribs of a fan. Some of the vannal veins may be branched, and secondary veins may alternate with the primary veins. The vannal region is usually best developed in the hindwing, in which it may be enlarged to form a sustaining surface, as in Plecoptera and Orthoptera. The great fanlike expansions of the hindwings of Acrididae are clearly the vannal regions, since their veins are all supported on

11564-528: The third axillary sclerites on the wing bases, though Martynov (1925) ascribes most of the fan areas in Acrididae to the jugal regions of the wings. The true jugum of the acridid wing is represented only by the small membrane (Ju) mesad of the last vannal vein. The jugum is more highly developed in some other Polyneoptera, as in the Mantidae. In most of the higher insects with narrow wings the vannus becomes reduced, and

11682-444: The title of "the indestructible insect." This title was bestowed on them after experimental interactions between velvet ants and their potential predators that resulted in the survival of the ant and the ultimate avoidance by the predator. The venom that velvet ants inject through their stinger has been investigated for five species of Dasymutilla , revealing that they are composed primarily of peptides. According to one researcher,

11800-421: The tracheal system. Several types of sensory neurons are found on insect wings: gustatory bristles , mechanosensory bristles, campaniform sensilla , and chordotonal organs . These sensors provide the nervous system with both external and internal proprioceptive feedback necessary for effective flight and grooming. In many insect species, the forewing and hindwing can be coupled together, which improves

11918-402: The tracheoles and the lumen of the trachea, and the uncoiling and stretching out of the tracheoles, so that they reach all parts of the wing. In the earlier stages of its development, the wing-bud is not provided with special organs of respiration such as tracheation, as it resembles in this respect the other portions of the hypodermis of which it is still a part. The histoblast is developed near

12036-412: The two forks of R8, the median cross-vein (m–m) between M2 and M3, and the mediocubital cross-vein (m-cu) between media and cubitus. The veins of insect wings are characterized by a convex-concave placement, such as those seen in mayflies (i.e., concave is "down" and convex is "up") which alternate regularly and by its triadic type of branching; whenever a vein forks there is always an interpolated vein of

12154-525: The two periods. The earliest winged insects are from this time period ( Pterygota ), including the Blattoptera , Caloneurodea , primitive stem-group Ephemeropterans , Orthoptera and Palaeodictyopteroidea . Very early Blattopterans (during the Carboniferous) had a very large discoid pronotum and coriaceous forewings with a distinct CuP vein (an unbranched wing vein, lying near the claval fold and reaching

12272-417: The usual position anterior to the group of anal veins, the remigium contains the costal, subcostal, radial, medial, cubital, and postcubital veins. In the flexed wing the remigiumturns posteriorly on the flexible basal connection of the radius with the second axillary, and the base of the mediocubital field is folded medially on the axillary region along the plica basalis (bf) between the median plates (m, m') of

12390-432: The vannal fold is lost, but even in such cases the flexed wing may bend along a line between the postcubitus and the first vannal vein. The Jugal Region, or Neala, is a region of the wing that is usually a small membranous area proximal to the base of the vannus strengthened by a few small, irregular veinlike thickenings; but when well developed it is a distinct section of the wing and may contain one or two jugal veins. When

12508-464: The veins becomes thickened and more heavily sclerotized to provide strength and rigidity to the wing. Two types of hair may occur on the wings: microtrichia, which are small and irregularly scattered, and macrotrichia, which are larger, socketed, and may be restricted to veins. The scales of Lepidoptera and Trichoptera are highly modified macrotrichia. In some very small insects, the venation may be greatly reduced. In chalcidoid wasps , for instance, only

12626-408: The veins has been used as evidence in determining the identities of the persisting distal branches of the veins of modern insects, but it has not been demonstrated to be consistent for all wings. Wing areas are delimited and subdivided by fold-lines along which the wing can fold, and flexion-lines along which the wing can flex during flight. The fundamental distinction between the flexion-lines and

12744-432: The veins in such a way that the cross-section of the wings approximates an airfoil . Thus, the wing's basic shape already is capable of generating a small amount of lift at zero angle of attack . Most insects control their wings by adjusting tilt, stiffness , and flapping frequency of the wings with tiny muscles in the thorax (below). Some insects evolved other wing features that are not advantageous for flight, but play

12862-421: The velvet ant would also stridulate after the shrew attacked it. Every time this occurred the shrew dropped the wasp. The exoskeleton of the velvet ant is remarkably strong. It required 11 times more force to crush than that of the honeybee. As well as being durable, the exoskeleton is also round, making it more difficult for predators to pierce it with attempted stings or bites. During all the trials that led to

12980-428: The wing at the base of the mediocubital field. The termen is the outer margin of the wing, between apex and hind or anal angle. At the posterior angle of the wing base in some Diptera there is a pair of membranous lobes (squamae, or calypteres) known as the alula. The alula is well developed in the house fly. The outer squama (c) arises from the wing base behind the third axillary sclerite (3Ax) and evidently represents

13098-423: The wing base. The vannus is bordered by the vannal fold, which typically occurs between the postcubitus and the first vannal vein. In Orthoptera it usually has this position. In the forewing of Blattidae, however, the only fold in this part of the wing lies immediately before the postcubitus. In Plecoptera the vannal fold is posterior to the postcubitus, but proximally it crosses the base of the first vannal vein. In

13216-410: The wing is the media. In the archetype pattern (A), the media forks into two main branches: a media anterior (MA), which divides into two distal branches (MA1, MA2), and a median sector, or media posterior (MP), which has four terminal branches (M1, M2, M3, M4). In most modern insects the media anterior has been lost, and the usual "media" is the four-branched media posterior with the common basal stem. In

13334-575: The wing posterior margin). Even though the oldest possible insect fossil is the Devonian Rhyniognatha hirsti , estimated at 396–407 million years old, it possessed dicondylic mandibles, a feature associated with winged insects, although it is later considered as possible myriapod . During the Permian , the dragonflies ( Odonata ) were the dominant aerial predator and probably dominated terrestrial insect predation as well. True Odonata appeared in

13452-414: The wing tracheae. Velvet ant Mutillinae Myrmillinae Pseudophotopsidinae Rhopalomutillinae Sphaeropthalminae Ticoplinae Velvet ants ( Mutillidae ) are a family of more than 7,000 species of wasps whose wingless females resemble large, hairy ants . Their common name velvet ant refers to their resemblance to an ant , and their dense pile of hair, which most often

13570-473: The wing, is primarily two-branched. The primary forking of the takes place near the base of the wing, forming the two principal branches (Cu1, Cu2). The anterior branch may break up into a number of secondary branches, but commonly it forks into two distal branches. The second branch of the cubitus (Cu2) in Hymenoptera, Trichoptera, and Lepidoptera was mistaken by Comstock and Needham for the first anal. Proximally

13688-411: The wing-flexing insects, where they constitute the flexor mechanism of the wing operated by the flexor muscle arising on the pleuron. Characteristic of the wing base is also a small lobe on the anterior margin of the articular area proximal to the humeral plate, which, in the forewing of some insects, is developed into a large, flat, scale-like flap, the tegula, overlapping the base of the wing. Posteriorly

13806-447: The wings, control and sensory systems , and anything else that affects aerodynamics or kinematics . One noteworthy trait is wing twist. Most insect wings are twisted, as are helicopter blades, with a higher angle of attack at the base. The twist generally is between 10 and 20 degrees. In addition to this twist, the wing surfaces are not necessarily flat or featureless; most larger insects have wing membranes distorted and angled between

13924-423: The wingstroke. Contraction of the dorsolongitudinal muscles causes the severe arching of the notum which depresses the wing while contraction of the dorsoventral muscles causes opposite motion of notum. The most primitive extant flying insects, Ephemeroptera (mayflies) and Odonata (dragonflies), use direct muscles that are responsible for developing the needed power for the up and down strokes. Insect wing muscle

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