"of vision known as the mosaic vision with more sensitivity but less resolution, being common during night, hence called nocturnal vision.), and is a very active night insect that shuns light. American cockroach nymphs are capable of limb regeneration. The American cockroach shows a characteristic insect morphology with its body bearing divisions as head, trunk, and abdomen. The trunk, or thorax, is divisible into prothorax, mesothorax and metathorax. Each thoracic segment gives rise to a pair of walking appendages (known as cursorial legs). The organism bears two pairs of wings. The fore wings, known as tegmina, arise from mesothorax, and"
"Its proximal end forms a more or less distinct head bent toward the femur, a device allowing the tibia to be flexed close against the under surface of the femur. The terms profemur, mesofemur and metafemur refer to the femora of the front, middle and hind legs of an insect, respectively. Similarly protibia, mesotibia and metatibia refer to the tibiae of the front, middle and hind legs. The tarsus of insects corresponds to the penultimate segment of a generalized arthropod limb, which is the segment called the propodite in Crustacea. adult insects it is commonly subdivided into from two to"
"Mesothorax The mesothorax is the middle of the three segments in the thorax of an insect, and bears the second pair of legs. Its principal sclerites (exoskeletal plates) are the mesonotum (dorsal), the mesosternum (ventral), and the mesopleuron (lateral) on each side. The mesothorax is the segment that bears the forewings in all winged insects, though sometimes these may be reduced or modified, as in beetles (Coleoptera) or Dermaptera, in which they are sclerotized to form the elytra (""wing covers""), and the Strepsiptera, in which they are reduced to form halteres. All adult insects possess legs on the mesothorax. In"
"Metathorax The metathorax is the posterior of the three segments in the thorax of an insect, and bears the third pair of legs. Its principal sclerites (exoskeletal plates) are the metanotum (dorsal), the metasternum (ventral), and the metapleuron (lateral) on each side. The metathorax is the segment that bears the hindwings in most winged insects, though sometimes these may be reduced or modified, as in Diptera, in which they are reduced to form halteres, or flightless beetles (Coleoptera), in which they may be completely absent even though forewings are still present. All adult insects possess legs on the metathorax. In"
"most groups of insects, the metanotum is reduced relative to the mesonotum. In the suborder Apocrita of the Hymenoptera, the first abdominal segment is fused to the metathorax, and is then called the propodeum. Metathorax The metathorax is the posterior of the three segments in the thorax of an insect, and bears the third pair of legs. Its principal sclerites (exoskeletal plates) are the metanotum (dorsal), the metasternum (ventral), and the metapleuron (lateral) on each side. The metathorax is the segment that bears the hindwings in most winged insects, though sometimes these may be reduced or modified, as in Diptera,"
"Mesosoma The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings. In hymenopterans of the suborder Apocrita (wasps, bees and ants), it consists of the three thoracic segments and the first abdominal segment (the propodeum). For historical reasons, in ants it is commonly referred to by the alternative name alitrunk. In scorpions, it is composed of six segments and forms the first part of the abdomen, containing all"
"Metasoma The metasoma is the posterior part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the mesosoma. In insects, it contains most of the digestive tract, respiratory system, and circulatory system, and the apical segments are typically modified to form genitalia. In a few of the most primitive insects (the Archaeognatha), the metasomal segments bear small, articulated appendages called ""styli"", which are often considered to be vestigial. There are also pre-apical appendages in most insect orders, called cerci, which may be multi-segmented and almost resembling a posterior"
"may or may not be visible, usually as a small triangular plate between the elytral bases, thus similar in position to the Hemipteran scutellum. In Diptera and Hymenoptera the mesothoracic scutellum is also distinct, but much smaller than the mesoscutum. Mesothorax The mesothorax is the middle of the three segments in the thorax of an insect, and bears the second pair of legs. Its principal sclerites (exoskeletal plates) are the mesonotum (dorsal), the mesosternum (ventral), and the mesopleuron (lateral) on each side. The mesothorax is the segment that bears the forewings in all winged insects, though sometimes these may be"
"Insect wing Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments (the mesothorax and metathorax), and the two pairs are often referred to as the forewings and hindwings, respectively, though a few insects lack hindwings, even rudiments. The wings are strengthened by a number of longitudinal veins, which often have cross-connections that form closed ""cells"" in the membrane (extreme examples include the dragonflies and lacewings). The patterns resulting from the fusion and cross-connection of the wing veins are often diagnostic for different evolutionary lineages and"
"while the internal branch is known as the endopod or endopodite. Other structures aside from the latter two are termed exites (outer structures) and endites (inner structures). Exopodites can be easily distinguished from exites by the possession of internal musculature. The exopodites can sometimes be missing in some crustacean groups (amphipods and isopods), and they are completely absent in insects. The legs of insects and myriapods are uniramous. In crustaceans, the first antennae are uniramous, but the second antennae are biramous, as are the legs in most species. For a time, possession of uniramous limbs was believed to be a"
"Corium (entomology) The corium is the thickened, leathery, basal portion of an insect forewing or hemelytron in the order hemiptera. Specifically the inner cell of the basal portion is the corium. The forewings of the winged aquatic bugs are modified into hemelytra (singular, hemelytron), in which the basal part is thickened and leathery and the apical part is membranous. The thickened region is divided into a corium and clavus. The membranous region has veins and the venation is of taxonomic importance. However, in many families, the distinction between the leathery and membranous regions of the hemelytron is not pronounced, and"
"have been lost or become vestigial through evolutionary adaptation, adult insects have six legs, one pair attached to each of the three segments of the thorax. They do also have paired appendages on some other segments, in particular, mouthparts, Antennae and cerci, all of which are suspected to be derived from paired legs on each segment of some common ancestor. Some larval insects do however have extra walking legs on their abdominal segments; these extra legs are called prolegs. They are found most frequently on the larvae of moths and sawflies. Prolegs do not have the same structure as modern"
"the wing tends to be more fully sclerotized (e.g., Pleidae) or more fully membranous (e.g., winged Gerridae). The hind wings are fully membranous and held beneath the hemelytra when at rest. Many adult aquatic bugs are brachypterous, micropterous, or apterous, having reduced wings or none at all. However, it is common that entomologists refer to the entire basal portion of the wing as the corium. Corium (entomology) The corium is the thickened, leathery, basal portion of an insect forewing or hemelytron in the order hemiptera. Specifically the inner cell of the basal portion is the corium. The forewings of the"
"the fusion of terga or terga and sterna to form continuous dorsal or ventral shields or a conical tube. Some insects bear a sclerite in the pleural area called a laterotergite. Ventral sclerites are sometimes called laterosternites. During the embryonic stage of many insects and the postembryonic stage of primitive insects, 11 abdominal segments are present. In modern insects there is a tendency toward reduction in the number of the abdominal segments, but the primitive number of 11 is maintained during embryogenesis.Variation in abdominal segment number is considerable. If the Apterygota are considered to be indicative of the ground plan"
"region when the wings are moved to the flight position. In general, wing extension probably results from the contraction of muscles attached to the basalar sclerite or, in some insects, to the subalar sclerite. The typical and usual segments of the insect leg are divided into the coxa, one trochanter, the femur, the tibia, the tarsus, and the pretarsus. The coxa in its more symmetrical form, has the shape of a short cylinder or truncate cone, though commonly it is ovate and may be almost spherical. The proximal end of the coxa is girdled by a submarginal basicostal suture that"
"insects are those whose nymphs, called naiads, occupy aquatic habitats while the adults are terrestrial. This includes all members of the orders Plecoptera, Ephemeroptera, and Odonata. Aquatic entomologists use this categorization because it specifies whether the adult will occupy an aquatic or semi aquatic habitat, or will be terrestrial. This classification system is similar to previously used nomenclature in terrestrial entomology. Hemimetabolism Hemimetabolism or hemimetaboly, also called incomplete metamorphosis and paurometabolism, is the mode of development of certain insects that includes three distinct stages: the egg, nymph, and the adult stage, or imago. These groups go through gradual changes; there"
"are two types of scolopidia, one whose distal end (the cap end) is contained within the body wall of the insect (subintegumental) or one whose distal end is free (integumental). For example, the integumental type is found in the subgenual organ (also known as the supratympanal organ) while the subintegumental type is found in the crista acustica and the intermediate organ. The subgenual organ ('organ below the knee') is found in all insects legs, and the probably an evolutionary artifact of prior insect body-types which used their legs to detect vibrations from the substrate (viz., treehoppers). The intermediate organ and"
"Hemimetabolism Hemimetabolism or hemimetaboly, also called incomplete metamorphosis and paurometabolism, is the mode of development of certain insects that includes three distinct stages: the egg, nymph, and the adult stage, or imago. These groups go through gradual changes; there is no pupal stage. The nymph often somewhat resembles the adult stage but lacks wings and functional reproductive organs. The Orders that contain hemimetabolous insects are: In aquatic entomology, different terminology is used when categorizing insects with incomplete metamorphosis. Paurometabolism refers to insects whose nymphs occupy the same environment as the adults, as in the family Gerridae of Hemiptera. The hemimetabolous"
"nudibranchs. In entomology, the notum is the dorsal portion of an insect's thoracic segment. The pterothoracic nota (comprising the meso- and metathoracic segments) have two main divisions - the anterior wing-bearing alinotum and the posterior phragma-bearing postnotom. The phragma, or endotergite, is a transverse infolding of the intersegmental sclerite, and its main function is to provide a reinforcing basis of attachment for the dorsal longitudinal muscles. Accordingly, phragmata tend to be best developed in actively flying insect species. In most winged insects, the structure of each successive notum is quite variable; in the Neoptera, the main flight muscles insert on"
"Elytron An elytron (; from Greek ἔλυτρον ""sheath, cover""; plural: elytra ) is a modified, hardened forewing of certain insect orders, notably beetles (Coleoptera) and a few of the true bugs (Hemiptera); in most true bugs, the forewings are instead called hemelytra (sometimes alternatively spelled as ""hemielytra""), as only the basal half is thickened while the apex is membranous. An elytron is sometimes also referred to as a shard. The elytra primarily serve as protective wing-cases for the hindwings underneath, which are used for flying. To fly, a beetle typically opens the elytra and then extends the hindwings, flying while"
"and sequestering its material for the new cuticle. When the new cuticle has formed sufficiently, the epicuticle and reduced exocuticle are shed in ecdysis. The four principal regions of an insect body segment are: tergum or dorsal, sternum or ventral and the two pleura or laterals. Hardened plates in the exoskeleton are called sclerites, which are subdivisions of the major regions - tergites, sternites and pleurites, for the respective regions tergum, sternum, and pleuron. The head in most insects is enclosed in a hard, heavily sclerotized, exoskeletal head capsule'. The main exception is in those species whose larvae are not"
"Tegmen A tegmen (plural: ""tegmina"") designates the modified leathery front wing on an insect particularly in the orders Dermaptera (earwigs), Orthoptera (grasshoppers, crickets and similar families), Mantodea (praying mantis), Phasmatodea (stick and leaf insects) and Blattodea (cockroaches). It is also a term used in botany to describe the delicate inner protective layer of a seed. In anatomy it denotes a plate of thin bone forming the roof of the middle ear. The term ""tegmen"" refers to a miscellaneous and arbitrary group of organs in various orders of insects; they certainly are homologous in the sense that they all are derived"
"with chitinous plates on the upper surface by the tergites and on the lower surface by the sternites. In scorpions, the metasoma is the tail. In other chelicerates, such as spiders, the mesosoma is fused with the metasoma to form the opisthosoma. Metasoma The metasoma is the posterior part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the mesosoma. In insects, it contains most of the digestive tract, respiratory system, and circulatory system, and the apical segments are typically modified to form genitalia. In a few of"
"Endopterygota Endopterygota, also known as Holometabola, is a superorder of insects within the infraclass Neoptera that go through distinctive larval, pupal, and adult stages. They undergo a radical metamorphosis, with the larval and adult stages differing considerably in their structure and behaviour. This is called holometabolism, or complete metamorphism. The Endopterygota are among the most diverse insect superorders, with about 850,000 living species divided between 11 orders, containing insects such as butterflies, flies, fleas, bees, ants, and beetles. They are distinguished from the Exopterygota (or Hemipterodea) by the way in which their wings develop. Endopterygota (meaning literally ""internal winged forms"")"
"Mandible (insect mouthpart) Insect mandibles are a pair of appendages near the insect’s mouth, and the most anterior of the three pairs of oral appendages (the labrum is more anterior, but is a single fused structure). Their function is typically to grasp, crush, or cut the insect’s food, or to defend against predators or rivals. Insect mandibles, which appear to be evolutionarily derived from legs, move in the horizontal plane unlike those of vertebrates, which appear to be derived from gill arches and move vertically. The mouthparts of orthopteran insects are often used as a basic example of mandibulate (chewing)"
"pair in males may be reduced to tiny hooks or stubs, while in others the first pair may be enlarged. Insects and their relatives are hexapods, having six legs, connected to the thorax, each with five components. In order from the body they are the coxa, trochanter, femur, tibia, and tarsus. Each is a single segment, except the tarsus which can be from three to seven segments, each referred to as a ""tarsomere"". A representative insect leg, such as that of a housefly or cockroach, has the following parts, in sequence from most proximal to most distal: Associated with the"
"turn composed of multiple segments. It is the area where the wings and legs attach in insects, or an area of multiple articulating plates in trilobites. In most insects, the thorax itself is composed of three segments; the prothorax, the mesothorax, and the metathorax. In extant insects, the prothorax never has wings, though legs are always present in adults; wings (when present) are restricted to at least the mesothorax, and typically also the metathorax, though the wings may be reduced or modified on either or both segments. In the Apocritan Hymenoptera, the first abdominal segment is fused to the metathorax,"
"remain inside the exoskeleton of the final larval instar and this last larval ""shell"" is called a puparium (plural, puparia). Flies of the group Muscomorpha have puparia, as do members of the order Strepsiptera, and the Hemipteran family Aleyrodidae. Pupa A pupa (, ""doll""; plural: ""pūpae"") is the life stage of some insects undergoing transformation between immature and mature stages. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, with four life stages: egg, larva, pupa, and imago. The processes of entering and completing the pupal stage are controlled by the insect's hormones, especially"
"hard plate called the pronotum, which is only the front part of the thorax; the back part of the thorax is concealed by the beetle's wings. This further segmentation is usually best seen on the abdomen. The multisegmented legs end in two to five small segments called tarsi. Like many other insect orders, beetles have claws, usually one pair, on the end of the last tarsal segment of each leg. While most beetles use their legs for walking, legs have been variously adapted for other uses. Aquatic beetles including the Dytiscidae (diving beetles), Haliplidae, and many species of Hydrophilidae, the"
"of legs. The meso- and metathoracic segments may each have a pair of wings, depending on the insect. The abdomen consists of eleven segments, though in a few species of insects, these segments may be fused together or reduced in size. The abdomen also contains most of the digestive, respiratory, excretory and reproductive internal structures. Considerable variation and many adaptations in the body parts of insects occur, especially wings, legs, antenna and mouthparts. The head is enclosed in a hard, heavily sclerotized, unsegmented, exoskeletal head capsule, or epicranium, which contains most of the sensing organs, including the antennae, ocellus or"
"Heteroptera The Heteroptera are a group of about 40,000 species of insects in the order Hemiptera. They are sometimes called ""true bugs"", though that name more commonly refers to the Hemiptera as a whole. ""Typical bugs"" might be used as a more unequivocal alternative, since the heteropterans are most consistently and universally termed ""bugs"" among the Hemiptera. ""Heteroptera"" is Greek for ""different wings"": most species have forewings with both membranous and hardened portions (called hemelytra); members of the primitive sub-group Enicocephalomorpha have completely membranous wings. The name ""Heteroptera"" is used in two very different ways in modern classifications. In Linnean"
"of maturation in some species. The imago is the only stage during which the insect is sexually mature and, if it is a winged species, has functional wings. The imago often is referred to as the adult stage. Members of the order Ephemeroptera (mayflies) do not have a pupal stage, but they briefly pass through an extra winged stage called the subimago. Insects at this stage have functional wings but are not yet sexually mature. The Latin plural of ""imago"" is ""imagines"", and this is the term generally used by entomologists – however, ""imagoes"" is also acceptable. ""Imago"" is Latin"
"arthropods, insects possess no legs on the abdomen in adult form, though the Protura do have rudimentary leg-like appendages on the first three abdominal segments, and Archaeognatha possess small, articulated ""styli"" which are sometimes considered to be rudimentary appendages. Many larval insects including the Lepidoptera and the Symphyta (Sawflies) have fleshy appendages called prolegs on their abdominal segments (as well as their more familiar thoracic legs), which allow them to grip onto the edges of plant leaves as they walk around. In arachnids (spiders, scorpions and relatives), the term ""abdomen"" is used interchangeably with ""opisthosoma"" (""hind body""), which is the"