Insect wing is an adult plant of an insect ecosystem that allows flying insects. They are found in the second and third thoracic segments (mesothorax and metathorax), and two pairs are often referred to as forewings and hindwings , respectively, although some insects have no hindwings, even rudiments. The wings are reinforced by a number of longitudinal veins, which often have cross-connections that form a "cell" enclosed in the membrane (extreme examples include dragonflies and lacewings). Patterns resulting from fusion and cross-connections of wing veins are often diagnostic for different evolution lines and can be used for identification to families or even genera levels in many insect orders.
Physically, some insects move their flight muscles directly, others indirectly. In the insect with direct flight, the wing muscle is directly attached to the base of the wing, so a small downward movement of the wing base lifts the wing itself upward. The insects with indirect flight have muscles that attach and damage the thorax, causing the wings to move as well.
Wings exist only one sex (often male) in groups such as velvet ants and Strepsiptera, or are selectively lost in social worker "workers" such as ants and termites. Rare, winged females but no males, as in fig wasps. In some cases, the wings are produced only at certain times in the life cycle, as in the aphid dispersal phase. Wings and color structures often vary with morphs, such as in aphids, migratory locusts and polymorphic butterflies. At rest, the wings can be held flat, or folded several times along a certain pattern; Most often, it is the hindwings that are folded, but in some groups like the vespid wasps, it is the forewings.
How and why the wings of insects evolved is not well understood and there has been a long debate about their origins. During the 19th century, the question of the evolution of the wings of insects initially rested on two main positions. One position of the insect's wing postulated is evolved from an existing structure, while the second proposed insect wing is entirely a new formation. The "new" hypothesis shows that the wings of insects are not formed from ancestral ancestors that exist but as a result of insect body walls.
Since then, research on the origins of insect insects has been built on the position of "pre-existing structures" originally proposed in the 19th century. Recent literature refers to some ancestral structures as an important part of the wings of insects. Among these include: gills, leg breathing appendages, and lateral (paranotal) and posterolateral thorax projections to name a few. According to more recent literature, gill-like structures and paranotal lobes are still visible among the most important ancestral structures for insect origin.
Today, there are three main theories about the origin of the flight of insects. These theories are referred to as paranotal lobe theory, gill theory and the dual theory of the evolution of the insect wings. These theories postulate that the wings develop well from the paranotal lobes, the extension of the thorax; that they modified the stomach gill move as found in the water naiad of the dragonflies; or that the wings of insects arise from a combination of existing endite and excite structures, each with pre-existing articulations and traits.
Video Insect wing
Morfologi
Internal
Each wing consists of a thin membrane supported by the venous system. The membrane is formed by two adjacent layers of the integument, while the vein is formed in which the two layers remain separate; sometimes the lower cuticle is thicker and more sclerotization under the veins. In each of the large blood vessels there are nerves and trachea, and, because of the cavity of the veins connected to the hemocoel, hemolymph can flow to the wings.
As the wings develop, the dorsal and ventral integral layers become very close in most of their regions forming the wing membranes. The remaining area forms a channel, a vein in the future, where nerves and trachea can occur. The cuticle around the vein becomes thickened and heavier sclerotized to give strength and stiffness to the wings. Two types of hair can occur on the wings: microtrichia, small and dispersed irregularly, and macrotrichia, larger, pockets, and may be confined to the veins. The scales of Lepidoptera and Trichoptera are highly modified macrotrichia.
Venacy
In some very small insects, the venation may be greatly reduced. In Chalcidoidea (Chalcid wasps), for example, only subcosta and part of the radius are present. On the contrary, an increase in venation may occur by branching existing blood vessels to produce additional veins or by the development of additional veins, between the original arteries, such as the Orthoptera wings (grasshoppers and crickets). A large number of cross-veins exist in some insects, and they can form reticulum as in Odonata wings (dragonflies and damselflies) and at the base of forewings Tettigonioidea and Acridoidea (katydids and grasshoppers).
Archedictyon is the name given to the hypothetical scheme of the proposed wing venation for the first winged insect. It is based on a combination of speculation and fossil data. Because all the winged insects are believed to have evolved from the same ancestor, archedictyon represents "templates" that have been modified (and simplified) by natural selection for 200 million years. According to the current dogma, archedictyon contains 6-8 longitudinal veins. These veins (and their branches) are named according to the system created by John Comstock and George Needham - the Comstock-Needham system:
- Subcosta (Sc) - second longitudinal vein (behind costa), usually not branched
- Radius (R) - the third longitudinal vein, one to five branches reaching the wing limit
- Medium (M) - the fourth longitudinal vein, one to four branches reaching the wing limit
- Cubitus (Cu) - the fifth longitudinal vein, one to three branches reaching the wing limit
- Anal vein (A1, A2, A3) - unbranched veins behind cubitus
Costa (C) is the main marginal vein in most insects, although sometimes there is a small vein above the costa called precosta, although in almost all the remaining insects precursions converge to costa; Costa rarely branched off from being on the cutting edge, which is basically linked with the humerus plate. The trachea of ​​the costal vein may be a branch of the subcostal trachea. Located after the costa is the third vein, subcosta, which branches into two separate veins: anterior and posterior. The subcostal base is associated with the distal end of the first axillary neck (see below). The fourth vein is radius (R), which branches into five separate blood vessels. His fingers are generally the strongest wings of the wings. To the center of the wing, the fork becomes the first undivided branch (R1) and the second branch, called the radial sector (Ra), which divides dichotomically into four distal branches (R2, R3, R4, R5). Basically, the fingers are flexibly united with the second axillary anterior end (2Ax).
The fifth vein of wings is media. In the archetype pattern A, the media fork becomes the two main branches: the anterior medium (MA), which is divided into two distal branches (MA1, MA2), and the median sector, or the posterior medium (MP), which has four terminal branches ( M1, M2, M3, M4). In most modern insects, anterior media has disappeared, and the usual "medium" is a posterior four-pronged medium with a common basal trunk. In Ephemerida, according to the present interpretation of wing venation, the two branches of the media are maintained, while in Odonata the surviving medium is the primitive anterior branch. The media rod is often put together with the fingers, but when it occurs as a different vein the base is related to the distal median plate (m ') or continues sclerotized with the latter. The cubitus, the sixth vein of the wings, mainly bifurcated. Major perforations occur near the base of the wing, forming two main branches (Cu1, Cu2). The anterior branches can split into several secondary branches, but usually the branch becomes two distal branches. The second branch of cubitus (Cu2) in Hymenoptera, Trichoptera, and Lepidoptera was misinterpreted by Comstock and Needham for the first anal. The proximal cubitus main trunk is associated with the distal median plate (m ') of the wing base.
Postcubitus (Pcu) is the first anal of the Comstock-Needham system. However, postcubitus has an independent wing vein status and should be recognized as such. In the nymph wings, the trachea emerges between the cubital trachea and the tracheal vannal group. In the more mature wings of the more common insects, Postcubitus is always associated proximal to the cubitus and has never been inextricably connected with the flexor sclerite (3Ax) of the wing base. In Neuroptera, Mecoptera, and Trichoptera, postcubitus may be more closely related to the vannal vein, but the base is always free of the latter. Postcubitus is usually not branched; it's a two branched primitive. The vannal vein (lV to nV) is the anal vein immediately associated with the third axilla, and which is directly affected by this sclerite movement that causes wing flexion. In the number of veins varies. from 1 to 12, according to the expansion of wing vannal area. Vannal trachea usually arises from a common tracheal trunk in nymphal insects, and the vein is considered a branch of a single anal vein. Suddenly the venous veins are either simple or branched. The jugal vein (J) of the wing lobe is often occupied by irregular venous tissue, or may be completely membrane; but sometimes containing one or two different veins, the first jugal vein, or the arcuate vein, and the second jugal vein, or the cardinal vein (2J).
- R cross-vein - run between branches of adjacent radius
- R-M cross-veins - runs between radius and media M-Cu cross-veins - run between media and cubitus
All wing veins are applied for secondary forking and association by cross-veins. In some insect orders, the veins are so numerous that all the venational patterns become tissues adjacent to the branched veins and veins. Usually, however, there is a definite number of cross-veins that have specific locations. A more constant cross-vein is a cross-vein (h) humerus between costa and subcosta, radial cross-vein (r) between R and Rs first fork, cross-vein (s) between both R8 fork, median cross- ) between M2 and M3, and mediocubital cross-vein (m-cu) between medium and cubite.
The blood vessels of the wings of insects are characterized by the placement of concave, as seen in the dragonflies (ie, concave is "down" and convex is "up") which alternates regularly and with triadic branching types; every time a venous fork there is always an interpolated vein from the opposite position between the two branches. The concave vein will branch off into two concave veins (with interpolated veins being convex) and regular vein changes are maintained. The wing veins seem to fall into a wavy pattern according to whether they have a tendency to fold up or down when the wings are relaxed. The basal shaft of the convex vein, but each fork is distal to the anterior convex branch and the posterior concave branch. Thus the costa and subcosta are considered as the convex and concave branches of the first primary vein, Rs is the concave branch of the radius, the posterior medium of the concave branch of the media, Cu1 and Cu2 each convex and concave, while the primitive Postcubitus and the first vannal have convex branches anterior and posterior sunken branches. The convex or concave nature of blood vessels has been used as evidence in determining the identity of the remaining distal branches of the modern insect vein, but has not been consistently proven for all wings.
Columns
The wing area is restricted and divided by folded lines as long as the wings can fold, and the flex-line along the wings can flex during the flight. The fundamental difference between line-flexion and fold-line is often blurred, because the fold-line may allow for flexibility or otherwise. Two constants found in almost all insect wings are claval (flexural line) and jugal fold (or fold line); forming variable limits and unsatisfactory. Wing folding can be very complicated, with transverse folding occurs at Dermaptera and Coleoptera locusts, and on some insects the anal area can be folded like a fan. There are about four different areas found on the wings of insects:
- Remigium
- Anal area (vannus)
- Save spaces
- Axillary area
- Alula
Most of the veins and crossveins occur in the anterior area of ​​the remigium, which is responsible for most flights, supported by the thoracic muscle. The posterior part of the remigium is sometimes called the clavus; the other two posterior areas are anal and frugal. When the vannal folds have an anterior position in the anal vein group, the remigium contains the costal, subcostal, radial, medial, cubital, and postcubital veins. In the flexed wing, posterior remigiumturns on the flexible basal connections of the radius with the second axillary, and the medocial base mediocubital folded in the axillary region along the basal plica (bf) between the median (m, m ') plate of the wing base.
Vannus is limited by the vannal fold, which usually occurs between postcubitus and the first vannal vein. In Orthoptera usually have this position. However, in Blattidae, the only folds in this wing section are located just before postcubitus. In Plecoptera the posterior vannal folds into postcubitus, but proximal across the venous base of the first vein. In a vocal folding cricket is located just behind the first venous vein (lV). Small variations in the actual position of the vannal fold, however, do not affect the unity of vannal vein action, controlled by the flexor sclerite (3Ax), in wing flexion. In most hindwings the Orthoptera vein of secondary dividens forms the ribs in the vannal folds. Vannus is usually triangular, and its blood vessels usually spread from the third axilla like a fan rib. Some venous veins can be branched, and the secondary vein may alternate with the primary veins. The vannal area is usually best developed in hindwing, where it can be enlarged to form a supporting surface, as in Plecoptera and Orthoptera. A large fan-like expansion on the back of Acrididae is clearly a vannal area, because their veins are all supported on the third axillary sclerite on the wing base, although Martynov (1925) considers most of the fan areas in Acrididae to the jugal area of ​​the wing. The true jugum acridid ​​wing is represented only by the small membrane (Ju) mesad of the last vein vein. The jugum is more developed in some other Polyneoptera, such as in Mantidae. In most of the higher insects with narrow wings, the vannus becomes reduced, and the vannal fold is lost, but even in such cases the bent wings may bend along the line between postcubitus and the first venous vein.
The Jugal Region, or Neala, is a wing area that is usually a small proximal membranous region to the base of the vannus reinforced by some small, irregular vein thickening; but when it develops well it is a different part of the wings and may contain one or two blood vessels. When the jugal region of the front wing is developed as a free lobe, it projects under the humerial angle of hindwing and thus serves to unite the two wings together. In the Jugatae group of Lepidoptera, it has a long lobe like a finger. The region of jugal is called neala ("new wing") because it is clearly a secondary and newly developed part of the wing.
The axillary region is an area containing axillary sclerite having a common form of an unequal side triangle. The base of the triangle (a-b) is the wing hinge with the body; apex (c) is the distal end of the third axillary sclerite; the longer side of the anterior to the top. The d point 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 basal plica (bf), or the wing folds at the base of the mediocubital plane.
At the posterior angle of the wing base in some Diptera there are a pair of membranous lobes (squamae, or calypteres) known as alula. Alula develops well in house flies. The outer squash (c) emerges from the base of the wing behind the third axillary sclerite (3Ax) and apparently represents the frugal lobe of another insect (A, D); (d) emerging from the posterior scutellar margin of the digested portion of the wings and forming a protective, canopy-like shell on the dumbbell. In the bent wing, the outer skuama of alula is reversed over the inner skuama, the latter unaffected by the wing movement. In many Diptera, a deep incision from the anus area of ​​the wing membrane behind a single vannal vein triggers the distal proximal alpha lobe to the outside of the alula.
Joints
Various wing movements, especially on insects that flex the wings horizontally over their backs during breaks, require a more complex articular structure at the base of the wing rather than just the wing hinges with the body. Each wing is attached to the body by the membranous basal region, but the articular membrane contains a number of small articular sclerites, collectively known as pteralia. The pteryia includes the anterior humerus plate at the base of the costal vein, a group of armpits (Ax) associated with the subcostal, radial, and vannal veins, and two undetermined median plates (m, m ') at the base of the mediocubital region. Axilla is specifically developed only on wing-flexing insects, where they are the flexor mechanism of the wing operated by flexor muscles arising in the pleuron. Characteristics of the wing base is also a small lobe on the anterior edge of the proximal articular region to the humerus plate, which, in the prohibition of some insects, develops into a large, flat flap, such as scale, tegula, overlap of the wing base. Posterior articular membranes often form considerable lobes between the wing and body, and their margins are generally thickened and wavy, giving the appearance of ligaments, called axillary aksilaris, mesial continuously with posterior marginal scutellar folds of the wing plate's unveiled plate.
The articular sclerites, or pteralia, from the wing-base of the wing-stretch insects and their relationship with the wing body and veins, shown diagrams, are as follows:
- The humerus plate
- First Axillary
- Second Axillary
- Third Axillary
- Fourth Root
- Median plates ( m , m ')
The humerus plate is usually a small sclerite on the anterior edge of the wing base, can be moved and articulated with the base of the costal veins. Odonates have their humerus plate enlarged, with two muscles arising from the episternum inserted into the Humeral plate and two from the edge of the epimeron inserted into the axilla plate.
The first axillary sclerite (lAx) is the anterior hinge plate of the wing base. The anterior portion is supported on the anterior process of the wing notes of the bergum (ANP); the posterior part articulates with the margin of the obstruction. The antler end of the sclerite is generally produced as a slender arm, the apex which (e) is always associated with the subcostal vein base (Sc), though not united with the latter. The scleritic body articulates laterally with a second axillary. The second axillary sclerite (2Ax) is more variable in shape than the first axilla, but its mechanical relationship is no less certain. It is tilted hinge to the outer edge of the first axillary body, and the radial (R) vein is always flexibly attached to the anterior end (d). The second axilla presents the dorsal and ventral sclerotization at the base of the wing; Its ventral surface rests on the pleural fulcral wing process. Therefore, the second axillary is the most important sclerite of the wing base, and specifically manipulates the radial vein.
The third axillary sclerite (3Ax) is located in the posterior part of the articular area of ​​the wing. The shape is highly variable and often irregular, but the third axillary is the sclerite which is inserted by the flexor muscle of the wing (D). Mesally it articulates anteriorly (f) with the posterior end of the second axillary, and posterior (b) with the posterior wing process of the bonded (PNP), or with the fourth axillary when the latter is present. The third axillary distal is extended in a process always associated with the base of the venous group in the anal region of the wing here called venous vein (V). Therefore, the third axis is usually the posterior hinge plate of the base of the wing and is the active sclerit of the flexor mechanism, which directly manipulates the vannal vein. The flexor muscle contraction (D) rotates the third axle at its articulation (b, f) and thereby raises its distal arms; this movement produces wing flexion. The fourth axillary sclerite is not a constant element of wing base. When present usually a small plate intervenes between the axillary third and the posterior wing process of the notepo and may be a separate part of the latter.
The median plates (m, m ') are also sclerites that are not so clearly distinguished as special plates such as the three major axes, but they are, after all, an essential element of the flexor apparatus. They are located in the median region of the distal wing base to the second and third axilla and are separated from each other by a slash (bf) that forms a prominent prominent crease during wing flexion. The proximal plate (m) is usually attached to the third distal arm of the armpit and may be considered part of the last. The distal plate (m ') is less always present as a distinct sclerite and can be represented by a generalized sclerotization of the base of the wing mediocubital plane. When blood vessels in these areas differ at their base, they are associated with the outer median plate.
Muscle
The muscles that control the fly on insects can reach up to 10% to 30% of the total body mass. The muscles that control the flight vary with the two types of flight found on insects: indirect and direct. Insects that use first, indirectly, have muscles attached to the non-winged column, as the name implies. When the muscles contract, the thoracic box becomes distorted, transferring energy to the wing. There are two "bundles" of muscles, which stretch parallel to the dummies, dorsolongitudinal, and which attach to the tegum and extend to the sternum, dorsoventral. In direct muscle, the direct connection of the pleuron (thoracic wall) to the individual sclerites located at the base of the wing. Subalar and basalar muscles have ligaments in the subalar and basalar sclerite. Here resilin, a very elastic material, forms a ligament that connects the flying muscles to the wing instrument.
In more sequences of insects, such as Diptera (fly) and Hymenoptera (wasps), the muscle does not directly occupy the largest volume of pterothorax and serves as the main source of force for wing style. Contraction of the dorsolongitudinal muscle causes a severe arch of the notum that compresses the wing while contraction of the dorsoventral muscle causes the opposite movement of the notes. Other more primitive insects, such as Orthoptera (grasshoppers), Coleoptera (beetles), and Odonata (dragonflies) use direct muscles responsible for developing the forces required for up and down motion.
Insect wing muscle is a very aerobic tissue. As per the protein unit it consumes fuel and oxygen at a rate that occurs in highly concentrated and highly organized networks so that the steady-state level per unit volume is an absolute record in biology. Blood rich in fuel and oxygen is brought into the muscle through the diffusion that occurs in large quantities, to keep the high energy levels used during flight. Many wing muscles are large and may be 10 mm long and 2 mm wide. In addition, in some Diptera the fibers have a gigantic dimension. For example, in highly active Rutilia , the cross section is 1800Ã,Âμm in length and over 500 Ã,Âμm in width. The transport of fuel and oxygen from the surrounding environment to places of consumption and carbon dioxide transport is therefore a challenge for biologists both in relation to transport in the liquid phase and in the complex air tube system, ie in the trachea. system.
Merge, fold and other features
In many species of insects, the front and rear wings are combined together, which increases the aerodynamic efficiency of the flight. The most common coupling mechanisms (eg, Hymenoptera and Trichoptera) are small hooks on the hindwing front margin, or "hamuli", which lock forward, keeping them together (hamulate coupling). In some other insect species (eg, Mecoptera, Lepidoptera, and some Trichoptera) the frugal lobes of the introduction include a portion of the hindwing (thin clutch), or a wider overlapping margin of wings (amplexiform coupling), or feather feathers rear, or frenulum, hooks under the retaining structure or retinaculum on the front wing.
At rest, the wing is held behind in most insects, which may involve longitudinal longitudinal wings folding and sometimes also transverse. Folding sometimes occurs along the line of flexion. Although folded lines can be transverse, such as on the back of beetles and earwigs, they usually co-exist with the wing base, allowing adjacent wing sections to be folded above or below each other. The most common fold line is the jugal crease, located just behind the third anal vein, though, most Neoptera have jugal folds just behind the 3A vein on the front wing. Sometimes also present in hindwings. Where the anal area of ​​a large hindwing, as in Orthoptera and Blattodea, this whole section can be folded beneath the anterior portion of the wing along the vannal folds slightly in posterior to the claval strain. In addition, in Orthoptera and Blattodea, the anus area is folded like a fan along the veins, the anal veins become convex, at the top of the folds, and the concave access basin. Whereas claval and jugal fold indentations may be homologous in different species, vannal folds vary in positions in different taxa. The folding is produced by the muscle that arises in the pleuron and is inserted into the third axillary sclerite such that, when contracting, sclerite pivots about its articulation point with the process of posterior notation and second axillary sclerite.
As a result, the third axle third sclerital distal arm rotates upward and inwards, so that the position is completely reversed. The anal veins are articulated with this sclerite in such a way that when moving they are carried with it and become bent over the backs of insects. The same muscle activity in flight affects the power output of the wings and is therefore also important in flight control. In orthopteroid insects, the elasticity of the cuticle causes the vannal area of ​​the wings to fold along the vein. As a result, energy is spent to open up this area when the wings are moved into flight positions. In general, wing extensions may result from muscle contractions attached to basalar sclerite or, to some insects, to the subalar sclerite.
Maps Insect wing
Flights
Flight mechanism
Two relatively large groups of insects, Ephemeroptera (dragonflies) and Odonata (dragonflies and damselflies) have flying muscles attached directly to their wings; wings can beat no faster than the speed at which nerves can send impulses to command the muscles to beat. All flying winged insects use different mechanisms, involving the indirect flight muscles that cause the thorax to vibrate; wings can beat faster than the speed at which muscles receive nerve impulses. This mechanism evolves once, and is a defining feature (synapomorphy) for Neoptera infraklass.
Aerodynamics
There are two basic aerodynamic models of insect flight. Most insects use methods that create the latest eddies. Some very small insects use a fling and clap or Weis-Fogh mechanism in which the wings clap together above the insect body and then part ways. When they open, the air gets sucked in and creates a vortex on each wing. This bound Vortex then moves across the wings and, in a pat, acts as an early whirl for another wing. Circulation and elevators are increasing, with prices worn and torn on the wings.
Many insects can hover by hitting their wings quickly, requiring side stabilization as well as lifting.
Some insects use airplanes, without using thrust. It is found in several species of arboreal ants, known as gliding ants.
Evolution
Once in the Carboniferous Age, some 350 million years ago, when there were only two large landmasses, insects began to fly. How and why the wings of insects develop, however, are not well understood, largely because of the appropriate fossil scarcity of their developmental period in the Lower Carboniferous. The three main theories about the origin of flying insects are that the wings develop from the paranotal lobes, the extension of the thorax; that they modified the stomach gill move as found in the water naiad of the dragonflies; or that they develop from the thoracic bulge used as a radiator.
Fossils
The fossils from Devonian (400 million years ago) are all without wings, but by Carboniferous (320 million years ago), more than 10 different genera have fully functional wings. There is little preservation of transitional forms between two periods. The earliest winged insects date from this time period (Pterygota), including Blattoptera, Caloneurodea, Ephemeropteran primitive stem groups, Orthoptera and Palaeodictyopteroidea. The very early blotting (during Carbon) has a very large discoid pronotum and foring coriacea with different CuP vein (unbranched wing vein, located near the claval fold and reaching the posterior margin). Although the oldest oldest insect fossil is the Devonian Rhyniognatha hirsti, estimated to be 396-407 million years old, it has the highest mandible, a feature associated with winged insects.
During the Permian, dragonflies Odonata are predominant air predators and may dominate predation of terrestrial insects as well. True Odonata appears in Permian and all are amphibians. Their prototype is the oldest winged fossil, back to Devonian, and different from the other wings in every way. Their prototype may have the beginnings of many modern attributes even by the late Carbon and perhaps they even capture small vertebrates, since some species have a wingspan of 71 cm. The earliest beetle species during the Permian has been pointed, skin like forewings with cells and holes. Hemiptera, or actual bugs have appeared in the form of Arctiniscytina and Paraknightia have forewings with unusual venation, possibly deviate from Blattoptera.
One large wing of the Diptera species in Triass (10 mm instead of 2-6 mm) is found in Australia (Mount Crosby). This family Tilliardipteridae, despite its many typhoid features, should be included in Psychodomorpha sensu Hennig because the loss of distal 1A reaches the wing limit and the formation of the anal loop.
Hypothesis
- Paranotal hypothesis : This hypothesis shows that the wings of insects evolved from the paranotal lobes, preadaptation found in fossil insects believed to have helped stabilize when jumping or falling. Supporting this hypothesis is the tendency of most insects, when shocked when climbing in branches, to escape by dropping to the ground. Such lobes will serve as parachutes and allow insects to land softer. This theory shows that these lobes gradually grow larger and in later stages develop joints with thorax. Even later will appear the muscles to move this rough wing. This model implies a progressive increase in wing effectiveness, starting with parachuting, then sliding and finally an active flight. However, the lack of substantial fossil evidence from the development of wing and muscle joints poses great difficulties for theory, as well as the seemingly spontaneous development of articulation and venation, and it has been rejected by experts in this field.
- Epicocal hypothesis : This theory suggests that the possible origin for the wings of insects is the found abdominal gills found in many water insects, such as the naiad of the dragonflies. According to this theory, these tracheal gills, which began their journey as a way out of the respiratory system and over time converted into locomotive goals, eventually evolved into wings. Trachea gills are equipped with small wings that continue to vibrate and have their own small straight muscles.
- Endite-exite hypothesis : The hypothesis with perhaps the strongest evidence is derived from the adaptation of endites and exites, complementary to the inner and outer aspects of each member of the primitive arthropod body. This was advanced by Trueman based on a research by Goldschmidt in 1945 on Drosophila melanogaster , where variations of
show mutations that transform the normal wings into what is interpreted as triple-setting foot jointed with some additional but less tarsus additions, where the costal wing will usually be. These mutations are reinterpreted as strong evidence for the dalal focal and endite fusion, rather than the legs, with complementary fits much better with this hypothesis. The innervation, articulation and muscles needed for wing evolution are already present in the podomeres.
- Paranota plus foot gene recruitment hypothesis : Coxoplectoptera larvae fossils provide important new clues to the contentious question about the origin of the evolution of insect wings. Prior to the discovery of larval fossils, the paranotal hypothesis and the hypothesis-leg-exite have been regarded as incompatible alternative explanations, both of which are supported by a series of evidence from fossil records, comparative morphology, developmental biology and genetics. The expression of leg genes in the ontogeny of insect wings has been universally regarded as conclusive evidence in favor of the exit-foot hypothesis, which suggests that the wings of insects are derived from complementary mobile legs (exites). However, Coxoplectoptera larvae show that the gills of the dragonfly fly and their ancestors, which are generally regarded as suitable structures for the wings of insects, are articulated in dorsal dipite plates. This can not be seen in modern dragonfly larvae, because their merging and sternit stomach merges with the ring, with no traces left behind even in embryonic development. If the gills and wings of the corresponding larvae ("homologous serial" structures) and thus have the same evolutionary origins, the new results of Coxoplectoptera show that also the wings are of origin, as proposed by the classical paranotal hypothesis. Staniczek, Bechly & amp; Godunko (2011) therefore suggests a new hypothesis that can reconcile seemingly contradictory evidence from paleontology and developmental genetics: the first wing originated as a stronger outcome than the paranotal plate (paranota), and only later in evolution became mobile, complementary articulated through recruiting secondary leg genes.
Suggestions have been made that the wings may have evolved initially to sail on the surface of the water as seen in some stone flies. An alternative notion is that it pushes from geared sliding glide air - a preflight phenomenon found in some apterygote, a winged taxi sister to a winged insect. The earliest pilots were similar to dragonflies with two pairs of wings, direct flight muscles, and no ability to fold their wings above their bellies. Most of today's insects, which evolved from the first leaflets, have been simplified into a pair of wings or two pairs that serve as a single pair and use indirect flight muscle systems.
Natural selection has played a huge role in perfecting the wings, controls and sensory systems, and anything that affects aerodynamics or kinematics. One important feature is the rotating wing. Most insect wings are twisted, as do helicopter blades, with a higher angle of attack at the base. The winding is generally between 10 and 20 degrees. In addition to this winding, the wing surface is not always flat or without properties; the largest insect has a distorted and angular wing membrane between the veins in such a way that the wing cross section approaches the airfoil. Thus, the wing base form is capable of generating a small amount of lift at the zero angle of attack. Most insects control their wings by adjusting the tilt, stiffness, and flapping of the wing frequency with the small muscles in the chest (below). Some insects develop other wing features that are unfavorable to fly, but play a role in other things, such as mating or protection.
Some insects, which occupy their biological niches, must be highly maneuverable. They must find their food in a narrow place and able to escape from larger predators - or they themselves are predators, and need to catch prey. Their maneuverability, from an aerodynamic point of view, is provided by high lift and thrust. Typical insect insects can achieve lift up to three times their weight and horizontal thrust force up to five times their weight. There are two substantially different insect flight mechanisms, each with its own advantages and disadvantages - just because odonates have a more primitive flight mechanism does not mean they are less capable of flying; they are, by certain means, more agile than anything that has developed afterwards.
Morphogenesis
While the development of the wings on insects is clearly defined in those who are members of Endopterygota, who undergo complete metamorphosis; in this species, the wings develop temporarily in the cocoon stage of the insect life cycle. However, insects with incomplete metamorphoses do not have a cocoon stage, therefore they must have different wing morphogenesis. Insects like those who are hemimetabolic have wings that start as buds, which are found under the exoskeleton, and do not become open until the last instar of the nymph.
The first indication of wing buds is hypodermic thickening, which can be observed in insect species as early embryos, and in the early stages of the life cycle. During the development of morphological features while in embryo, or embryogenesis, a group of cells grows under the ectoderm which is later in progression, after the lateral ectoderm has grown dorsally to form the imaginal wind discs. Examples of wingspan development in larvae can be seen in white butterflies ( Pieris ). In the second instar the histoblast becomes more prominent, which now forms a bag-like structure. In the third and fourth instars, the histoblast becomes more elongated. A very broad and revealing, or prominent part, this is the wing. At the last instar closing, or fifth, the wings are pushed out of the wing-pocket, although they remain below the old larval cuticle while in the preparation stage. Not until the butterfly is in the stage of its cocoon so that the wing buds open, and shortly after the eclosion, the wings begin to expand and form its definitive shape.
The development of wing tracheation begins before the wing histoblasts are formed, as it is important to note that they develop near the large trachea. During the fourth instar, the cells of the tracheal epithelium become very enlarged up to the wing bud's cavity, with each cell having developed a tightly coiled tracheole. Each trachcole is of unicellular origin, and in the first intracellular position; while the trachea is derived from multicellular and each lumen has an intercellular position. The development of tracheoles, each circular within a single cell of the tracheal epithelium, and the opening of communication between the tracheoles and the tracheal lumen, and the opening and stretching out of the tracheoles, so that they reach all the parts. of the wings.
In the early stages of development, wing buds are not equipped with special respiratory organs such as tracheation, as it resembles in this other part of the hypodermis that is still part of it. It should be noted, however, that histoblast is developed near the large trachea, the cross-section shown in, which is part of the parts of the first, second, third and fourth instars respectively. At the same time tracheoles unroll, and extend in bundles in the vein-forming cavities of wing buds. In the turmoil that marked the beginning of the stage of the cocoon stadium, they became functional. At the same time, tracheoles of larvae degenerate; Their function has been replaced by the wing trachea.
Nomenclature
Most of the order nomenclature of insects is based on the Ancient Greek word for wings, ?????? ( pteron ), as -ptera suffix.
Adaptations
Variations
The wings of insects are very important in identifying and classifying species because no other structure in the study of insects is more significant. Each order and family of insects has a distinctive wing shape and features. In many cases, even species can be distinguished from each other by different colors and patterns. For example, only with one's position can identify species, albeit at a much lower level. Although most insects fold their wings while resting, dragonflies and some damselflies rest with their wings spread horizontally, while groups such as caddisflies, stonefly, fly flies, and lacewings hold their wings sloping like a roof over their backs. Some moths wrap their wings around their bodies, while many flies and large butterflies cover their wings together straight up over the back.
Often the shape of the wing is correlated with the type of insect flight. The best flying insects tend to have long, slender wings. In many species of Sphingidae (sphinx moths), the large and sharp front wings point, forming with small, triangular hindwings that are suggestive of fast wings, modern planes. Another possible correlation is the size and strength of muscles with the speed and power of flight. On a flying insect, its wings are best suited for aerial pressure and aerodynamics. The blood vessels are thicker, stronger, and closer to the leading edge (or "leading edge") and are thinner but flexible toward the rear edge (or "trailing edge"). This makes the wing of the insect into an airfoil that is made very well, able to mobilize the driving force and lift while minimizing the obstacles.
Wing impact variations can also occur, not only among different species, but even among individuals at different times. In general, the frequency depends on the ratio between the strength of the wing muscle and the load resistance. Large, light-bodied butterflies may have 4-20 rhythms of wings per second while smallish flies, heavy-bodied flies and bees defeat their wings more than 100 times per second and mosquitoes can hit up to 988-1046 times. Just a moment. The same applies to aviation; although it is generally difficult to estimate the speed of insects in flight, most insects may fly faster in nature than they do in controlled trials.
Coleoptera
In Coleoptera species (beetles), the only functional wings are hindwings. The hinge is longer than elytra, folded longitudinally and transverse under elytra. The wings are turned forward essentially into flight positions. This action spreads the wings and stretches longitudinally and transversely. There is a spring mechanism in the wing structure, sometimes with the help of abdominal motion, to keep the wings in folded position. The beetle wing fusion is reduced and modified due to folding structures, which include:
- Costa (C) , Subcostial posterior (ScP) - at the margin of the leading wing, fused for most of the length.
- The anterior radius (RA) - is divided into two branches outside the center of the wing.
- Posterior radius (RP) - basal connection is lost.
- Posterior media (MP) - branches, long and strong veins.
- anterior cubitus (CuA)
- Anal veins (AA, AP) - veins behind the cubitus, separated by anal creases.
In most species of beetles, a pair of front wings are modified and scratched to form elytra and they protect the smooth, folded hindwings underneath. Elitra connected to pterathorax; called like that because it is where the wing is connected ( pteron meaning "wing" in Greek). Elytra is not used for flights, but tends to cover the back of the body and protect the second pair of wings ( alae ). Elytra should be raised to move the rear flight wing. The flying wing of a beetle is crossed with veins and folded after landing, often along these veins, and kept under elytra. In some beetles, the ability to fly has been lost. These include some ground beetles (Carabidae family) and some "real beetles" (the Curculionidae family), but also some species that live in deserts and caves in other families. Many of these species have two elytra joined together, forming a solid shield on the abdomen. In some families, the ability to fly and elytra have disappeared, with the most famous example being the worm-glow of the family Phengodidae, in which larviform females throughout their lifetime.
Lepidoptera
Two pairs of wings are found in the middle and third segments, or mesothorax and metathorax respectively. In newer genera, the second segment wings are much more prominent, but some more primitive forms have the same-sized wings of both segments. The wings are covered with scales arranged like shingles, forming an extraordinary variation seen in color. Mesothorax evolved to have stronger muscles to drive moths or butterflies through the air, with the segment's wings having a stronger vein structure. The largest superfamily, Noctuidae, has wings that are modified to act as Tympanal or hearing organs. Modifications in wing venation include: Costa
The wings, the head of the thorax and the belly of Lepidoptera are covered with small scales, from which the order 'Lepidoptera' takes its name, the word "lepteron" in Ancient Greek which means 'scale'. Most scales are flat-shaped, or like blades and attached with pedicels, while other forms may be hair-like or special as secondary sexual characteristics. Lumen or lamella surface, has a complicated structure. It gives good color because of the color of the pigment contained within or because of the three-dimensional structure. The scales provide a number of functions, including isolation, thermoregulation, aiding in flight, among others, the most important of which is the large diversity of clear or unclear patterns they provide that help the organism protect itself by camouflage, mimicry,.
Odonata
Odonata species (Damselflies and dragonflies) both have two pairs of wings that are approximately the same in size and shape and are clear in color. There are five, if R M is counted as 1, the main vein comes from dragonflies and wings damselfly, and the wing veins coalesce in their base and the wings can not be folded above the body at rest, which also includes:
- Costa (C) - at the leading edge of the wing, strong and marginal, extending to the apex of the wing.
- Subcosta (Sc) - a second longitudinal vein, unbranched, joining C at the node.
- Radius and Medium (RM) - the third and fourth longitudinal veins, the strongest veins on the wings, with branches, R1 -R4, reach wing limit, anterior media (MA) also reach the wing limit. IR2 and IR3 are the anterior veins behind R2 and R3.
- Cubitus (Cu) - the fifth longitudinal vein, posterior cubitus (CuP) is not branched and reaches the wing limit.
- Anal vein (A1) - unbranched veins behind the cubitus.
- A node is formed in which the second main vein meets the leading edge of the wing. The black pterostigma was brought near the wingtips.
The main vein and crossveins form a wing pattern of venation. The pattern of the vein differs in different species. There may be a lot of crossovers or fewer. Australia's Flatwing Damselfly wing is one of the few vein patterns. The pattern of venation is useful for species identification. Almost all Anisoptera silence with the wings lifted to the side or slightly down, but most of the Zygoptera settle with the wings united, the dorsal surface visible. The thorax of Zygoptera is so tilted that when held in this manner the wings fit in the upper part of the abdomen. They do not look perpendicular like butterflies or dragonflies. In some zygopteran families, the wings are held horizontally at rest, and in one genus anisopteran (eg Cordulephya, Corduliidae) the wings are held in a distinctive resting position. The adult species has two pairs of equal or equal wings. Apparently there are only five main vein rods. A node is formed in which the second major vein (subcosta) meets the leading wing. In most families, a striking pterostigma is brought near the wingtips. Identification as Odonata can be based on venation. The only confusion is with some lacewings (order Neuroptera) which has a lot of crossveins on the wings. Until the early years of the 20th century, Odonata was often thought to be linked to lacewing and given the ordinal name of Paraneuroptera, but the similarity between these two orders is completely superficial. At Anisoptera, hindwing is wider than the front wing and on both wings, a cross-sect divides the disco cell into Triangle and Supertriangle.
Orthoptera
Orthoptera species (grasshoppers and crickets) have a hard, narrow forked forewings that normally cover the hindwings and abdomen at rest. The hindwings are membranous boards and folded in a fan-like manner, which includes the following venations:
- Costa (C) - at the foremost marginal of the front and rear wings, not branched.
- Subcosta (Sc) - a second longitudinal vein, not branched.
- Radius (R) - a third longitudinal vein, bifurcated to Rs in forewing and hindwing.
- The anterior media (MA) - the fourth longitudinal vein, branched in the basal section as the Posterior Media (MP).
- Cubitus (Cu) - the fifth longitudinal vein, on the front and rear wings that splits near the wing base to the branched CuA, and CuP is not branched.
- Anal veins (A) - the vein behind the cubitus, unbranched, two on the front, much behind.
Phasmatodea
- Costa (C) - at the front marginal at the back, unbranched, not present at the beginning.
- Subcosta (Sc) - a second longitudinal vein, not branched.
- Radius (R) - a third longitudinal vein, branching out to Rs in hindwing, not branched in forewing.
- The anterior media (MA) - the fourth longitudinal vein, branched in the basal section as the Posterior Media (MP).
- Cubitus (Cu) - the fifth longitudinal vein, not branched.
- Anal veins (A) - the vein behind the cubitus, not branched, two on the front, many behind 1A-7A in one group and the rest in another group.
Stick insect has a formidable forewings, opaque, short, and just cover the base of the hindwings at rest. Hindwing from costa to Cubitus is difficult and opaque like the front wing. Large anal areas are membranous and folded in a fan-like manner. There is no or very little branching in the wing vein of a stick insect.
Dermaptera
Other commands such as Dermaptera (earwigs), Orthoptera (grasshopper, crickets), Mantodea (worship mantis) and Blattodea (cockroaches) have rigidly rigid loudspeakers that do not flap when flying, sometimes called tegmen . tegmina ), elytra , or pseudoelytron .
Hemiptera
In Hemiptera (the real bug), forewings may harden, albeit at a lower level than in beetles. For example, the anterior portion of the front wing of the odor insects is hardened, while the posterior part is the membrane. They are called hemelytron (pl. hemelytra ). They are only found in the Heteroptera suborder; Homoptera wings, like crickets, are usually completely membranes. Both the forewings and the hindwings of Cicada are membranous, most of the glass-like species though some are opaque. Cicadas is not a good aviator and most fly only a few seconds. When flying, the front wing and rear wing are connected together by a curved clutch along the rear costa and front wing. Most species have a basic venation as shown in the following figure.
- Costa (C) - at the leading margin of the wings, the prefix extends to the node and lies close to Sc R.
- Radius (Sc R) - at the beginning of Sc and R fused together into the node. The radial sector (Rs) appears near the node and is not branched.
- The anterior radius (RA)
- Posterior radius (RP)
- Media (M) - branches to M1 to M4.
- anterior cubitus (CuA) - branched off to CuA1 and CuA2.
- Positive cubitus (CuP) - not branched.
- Anal veins (A) - the vein behind the cubitus, 1A and 2A fused on the front, CuP and 2A folded.
Also notice there is an ambient vein and a peripheral membrane on the second margin of the wing.
Diptera
In Diptera (true fly), there are only a pair of functional wings, with a pair of posterior wings reduced to a dumbbell, which helps flies to sense their orientation and movement, and to improve balance by acting similarly to a gyroscope. In Calyptratae, the rearmost part of the wing is modified into a kind of thick fold called the calypters that cover the halteres.
- Costa (C) - not found on Diptera.
- Subcosta (Sc) - becomes the leading wing vein, not branched.
- Radius (R) - branched off to R1-R5.
- Media (M) - branched off to M1-M4.
- anterior cubitus (CuA) - not branched, CuP decreases in Diptera. Some CuA and 1A species are separated, some species meet when reaching the wing limit, some species converge.
- Anal veins (A) - only two anal vein 1A and 2A are present, 2A is not different in some species.
- Discal Cell (dc) - well defined in most species. Blattodea
- Costa (C) - at the forefront of the wing.
- Subcosta (Sc) - a second longitudinal vein, relatively short.
- Radius (R) - a third longitudinal vein, with many pectinic branches.
- Medium (M) - the fourth longitudinal vein, reaching the wing limit.
- anterior cubitus (CuA) - the fifth longitudinal vein, with the dichotomous branch occupying most of the tegmen.
- Posterior cubitus (CuP) - unbranched, curved and reaches the wing limit.
- Anal vein (A) - the vein behind the cubitus.
- Subcosta (Sc) - not branched.
- Radius (R) - branched off to R1-R5.
- Medium (M) - M is not branched, at the beginning M is combined with Rs for its length.
- Cubitus (CuA) - unbranched, CuP is not in Hymenoptera.
- Anal veins (A) - only two anal vein 1A and 2A are present, 2A is not different in some species.
- Wing-coupling - Rows of hooks on the front end of hindwing involve the rear margin of the front wing, deeply paired with in-flight wings.
- Wings folding line - Some species, including Vespidae, are folded longitudinally along the 'wing fold' during breaks.
- Pterostigma - is present for some species.
The Blattodea species (cockroach) have forewing, also known as tegmen, which are more or less sclerotized. It is used in flight as well as a form of protection from membranous hindwings. The blood vessels of hindwing are almost identical to the front wings but with large anal lobes folded at rest between CuP and 1A. The anal lobe is usually folded in a fan-like manner.
Hymenoptera
Hymenoptera adults, including flies, wasps, bees and ants that do not work, all of which have two pairs of membranous wings. Costa
The forward margin of hindwing contains a number of bent feathers, or "hamuli", which lock forward, keeping them together. Smaller species may have only two or three hamuli on each side, but the largest wasps may have a sizeable number, keeping the wings firmly fixed, especially very closely. Hymenopteran wings have relatively few veins compared to many other insects, especially in smaller species.
Other families
Termites are relatively poor and easy to blow against wind in wind speeds of less than 2 km/h, spilling their wings soon after landing in an acceptable place, where they are paired and trying to form a nest in wood or wet soil. Most termite wings have three heavy veins along the basal portion of the front edge of the front wing and crossveins near the tip of the inclined wing, making the trapezoidal cells. Although the subterranean termite wings have only two large veins along the front edge of the front wing and the veins of the cross toward the wingtips perpendicular to these veins, making the cells square and rectangular.
Spesies Thysanoptera (thrip
Source of the article : Wikipedia
0 Comments