"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"
"for ""image"". Imago In biology, the imago is the last stage an insect attains during its metamorphosis, its process of growth and development; it also is called the imaginal stage, the stage in which the insect attains maturity. It follows the final ecdysis of the immature instars. In a member of the Ametabola or Hemimetabola, in which metamorphosis is ""incomplete"", the final ecdysis follows the last immature or ""nymphal"" stage. In members of the Holometabola, in which there is a pupal stage, the final ecdysis follows emergence from the pupa, after which the metamorphosis is complete, although there is a"
"Imago In biology, the imago is the last stage an insect attains during its metamorphosis, its process of growth and development; it also is called the imaginal stage, the stage in which the insect attains maturity. It follows the final ecdysis of the immature instars. In a member of the Ametabola or Hemimetabola, in which metamorphosis is ""incomplete"", the final ecdysis follows the last immature or ""nymphal"" stage. In members of the Holometabola, in which there is a pupal stage, the final ecdysis follows emergence from the pupa, after which the metamorphosis is complete, although there is a prolonged period"
"which the insect leaves the chamber as an adult. With favorable weather the entire development lasts four to five months. The oviposition takes place in April or May, so the weevils emerge in August or September, but are not sexually active until after the winter. The imago lives from two to three years, during which it reproduce in following seasons. In colder seasons the larval development is longer and then the whole cycle lasts twelve months, resulting that imagos able to reproduce quickly. Biennial generation it is also common, by which the larvae hatch from eggs laid in May, live"
"Imaginal disc An imaginal disc is one of the parts of a holometabolous insect larva that will become a portion of the outside of the adult insect during the pupal transformation. Contained within the body of the larva, there are pairs of discs that will form, for instance, the wings or legs or antennae or other structures in the adult. The role of the imaginal disc in insect development was first elucidated by Jan Swammerdam. During the pupal stage, many larval structures are broken down, and adult structures, including the discs, undergo rapid development. Each disc everts and elongates, with"
"were probably feeding in this phase of life too as the lines between the instars were much more diffuse and gradual than today). Adult form was reached several moults before maturity. They probably didn't have more instars after becoming fully mature. This way of maturing is how Apterygota do it, which moult even when mature, but not winged insects. Modern mayflies have eliminated all the instars between imago and nymph, except the single instar called subimago, which is still not (at least not in the males) fully sexually mature. The other flying insects with incomplete metamorphosis (Exopterygota) have gone a"
"the insect is the winged adult or imago. The surface of both butterflies and moths is covered by scales, each of which is an outgrowth from a single epidermal cell. The head is small and dominated by the two large compound eyes. These are capable of distinguishing flower shapes or motion but not for clearly viewing distant objects. Colour perception is good, especially in some species in the blue/violet range. The antennae are composed of many segments and have clubbed tips (unlike moths that have tapering or feathery antennae). The sensory receptors are concentrated in the tips and can detect"
"adapt to the best way of living and surviving despite their limitations till the moment came when they could leave them behind. This would be a starting point in the evolution where imago and nymphs started to live in different niches, some more clearly defined than others. Also, a final anatomy, size and maturity reached at once with a single final nymphal stage meant less waste of time and energy, and also made a more complex adult body structure. These strategies obviously became very successful with time. Evolution of insects The most recent understanding of the evolution of insects is"
"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"
"collar and a central, domed nipple region, and the larva weaves salivary ""silk"" threads in a circular pattern in this region. The larva also uses its digestive contents to form smears on the cocoon, leading to hardening of the cocoon and a color change to a dark, red-brown. In this stage, in which the organism becomes classified as an imago, the metabolic rate of the imago declines because it must have enough food to survive the winter. Both the imago's body weight and fat body weight decrease. Male larvae are placed in front of the females within the nest, allowing"
"structures such as cocoons, nests, or shells. The pupal stage follows the larval stage and precedes adulthood (""imago"") in insects with complete metamorphosis. The pupa is a non-feeding, usually sessile stage, or highly active as in mosquitoes. It is during pupation that the adult structures of the insect are formed while the larval structures are broken down. The adult structures grow from imaginal discs. Pupation may last weeks, months, or even years, depending on temperature and the species of insect. For example, pupation lasts eight to fifteen days in monarch butterflies. The pupa may enter dormancy or diapause until the"
"initiates insect molting. Then, the larva puparium, a sclerotized or hardened cuticle of the last larval instar, develops into the pupa. Depending on the species, the pupa may be covered in a silk cocoon, attached to different types of substrates, buried in the ground, or may not be covered at all. Features of the imago are externally recognizable in the pupa. All the appendages on the adult head and thorax are found cased inside the cuticle (antennae, mouthparts, etc.), with the wings wrapped around, adjacent to the antennae. The pupae of some species have functional mandibles, while the pupal mandibles"
"Instar An instar (, from the Latin ""form"", ""likeness"") is a developmental stage of arthropods, such as insects, between each moult (""ecdysis""), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width. After moulting, i.e. shedding their exoskeleton, the juvenile arthropods continue in their life cycle until they either pupate or moult again. The instar period of growth is fixed; however, in some insects, like the salvinia stem-borer"
"subimago that physically resembles the adult, but which is usually sexually immature and duller in colour. The subimago often has partially cloudy wings fringed with minute hairs; its eyes, legs and genitalia are not fully developed. Subimagos are generally poor fliers, and typically lack the colour patterns used to attract mates. After a period, usually lasting one or two days but in some species only a few minutes, the subimago moults to the full adult form, making mayflies the only insects where a winged form undergoes a further moult. Adult mayflies, or imagos, are relatively primitive in structure, exhibiting traits"
"types: obtect, exarate, and coarctate. Obtect pupae are compact, with the legs and other appendages enclosed, such as a butterfly chrysalis. Exarate pupae have their legs and other appendages free and extended. Coarctate pupae develop inside the larval skin. The final stage of holometabolous insect development is the adult, or imago. Most adult insects have wings (excepting where secondarily lost) and functioning reproductive organs. Most adult insects grow very little after eclosion from the pupa. Some adult insects do not feed at all, and focus entirely on mating and reproduction. Around 45% to 60% of all known living species are"
"tympanal apparatus. The adult insect, known as an imago, is in total length in most species, although the largest, the empress cicada (""Megapomponia imperatoria""), has a head-body length of about , and its wingspan is . Cicadas have prominent compound eyes set wide apart on the sides of the head. The short antennae protrude between the eyes or in front of them. They also have three small ocelli located on the top of the head in a triangle between the two large eyes; this distinguishes cicadas from other members of the Hemiptera. The mouthparts form a long sharp rostrum that"
"more during its life. A complex process controlled by hormones, it includes the cuticle of the body wall, the cuticular lining of the tracheae, foregut, hindgut and endoskeletal structures. The stages of molting: Insect physiology Insect physiology includes the physiology and biochemistry of insect organ systems. Although diverse, insects are quite similar in overall design, internally and externally. The insect is made up of three main body regions (tagmata), the head, thorax and abdomen. The head comprises six fused segments with compound eyes, ocelli, antennae and mouthparts, which differ according to the insect's particular diet, e.g. grinding, sucking, lapping and"
"and shape. The new integument still is soft and usually is pale, and it is said to be teneral or callow. It then undergoes a hardening and pigmentation process that might take anything from several minutes to several days, depending on the nature of the animal and the circumstances. Arthropod cuticle The cuticle forms the major part of the integument of the Arthropoda. It includes most of the material of the exoskeleton of the insects, Crustacea, Arachnida, and Myriapoda. In arthropods, the integument, the external ""skin"", or ""shell"", is the product of a single layer of ectodermal epithelium. That layer"
"of metamorphosis: incomplete metamorphosis and complete metamorphosis. Hemimetabolous insects, those with incomplete metamorphosis, change gradually by undergoing a series of molts. An insect molts when it outgrows its exoskeleton, which does not stretch and would otherwise restrict the insect's growth. The molting process begins as the insect's epidermis secretes a new epicuticle inside the old one. After this new epicuticle is secreted, the epidermis releases a mixture of enzymes that digests the endocuticle and thus detaches the old cuticle. When this stage is complete, the insect makes its body swell by taking in a large quantity of water or air,"
"a hard outer layer made mostly of chitin which protects and supports the body. The insect body is divided into three parts: the head, thorax, and abdomen. The head is specialized for sensory input and food intake; the thorax, which is the anchor point for the legs and wings (if present), is specialized for locomotion; and the abdomen for digestion, respiration, excretion, and reproduction. Although the general function of the three body regions is the same across all insect species, there are major differences in basic structure, with wings, legs, antennae, and mouthparts being highly variable from group to group."
"classified by their body type: The larval stage is variously adapted to gaining and accumulating the materials and energy necessary for growth and metamorphosis. Most holometabolous insects pass through several larval stages, or instars, as they grow and develop. The larva must moult to pass from each larval stage. These stages may look very similar and differ mostly in size, or may differ in many characteristics including, behavior, color, hairs, and spines, and even number of legs. Differences between larval stages are especially pronounced in insects with hypermetamorphosis. The final larval stage in some insects is called a prepupa. Prepupae"
"Insect physiology Insect physiology includes the physiology and biochemistry of insect organ systems. Although diverse, insects are quite similar in overall design, internally and externally. The insect is made up of three main body regions (tagmata), the head, thorax and abdomen. The head comprises six fused segments with compound eyes, ocelli, antennae and mouthparts, which differ according to the insect's particular diet, e.g. grinding, sucking, lapping and chewing. The thorax is made up of three segments: the pro, meso and meta thorax, each supporting a pair of legs which may also differ, depending on function, e.g. jumping, digging, swimming and"
"moth, the number of instars depends on early larval nutrition. Some arthropods can continue to moult after sexual maturity, but the stages between these subsequent moults are generally not called instars. For most insect species, an ""instar"" is the developmental stage of the larval forms of holometabolous (complete metamorphism) or nymphal forms of hemimetabolous (incomplete metamorphism) insects, but an instar can be any developmental stage including pupa or imago (the adult, which does not moult in insects). The number of instars an insect undergoes often depends on the species and the environmental conditions, as described for a number of species"
"External morphology of Odonata Odonata (dragonflies and damselflies) are insects with an incomplete metamorphosis (hemimetabolous). The aquatic larva or nymph hatches from an egg, and develops through eight to seventeen instars before leaving the water and emerging as the winged adult or imago. The imago (adult stage) has a large head, well-developed, compound eyes, legs that facilitate catching prey (largely other insects) in flight, two pairs of long, transparent wings that move independently, and an elongated abdomen. Many Odonata are relatively large insects, but wingspans range from 17 mm (some ""Agriocnemis"" damselflies) to 191 mm (helicopter damselfly ""Megaloprepus coerulatus"". The"
"greater differences between the adults and the first instars, instead of just gradually growing bigger as earlier generations had done. This evolutionary trend explains how they went from ametabolous to hemimetabolous insects. Reaching maturity and a fully-grown body became only a part of the development process; gradually a new anatomy and new abilities - only possible in the later stages of life - emerged. The anatomy insects were born and grew up with had limitations which the adults who had learned to fly didn't have. If they couldn't live their early life the way adults did, immature individuals had to"
"stage in most butterflies is one in which there is little movement. However, some butterfly pupae are capable of moving the abdominal segments to produce sounds or to scare away potential predators. Within the chrysalis, growth and differentiation occur. The adult butterfly emerges (ecloses) from this and expands its wings by pumping haemolymph into the wing veins. Although this sudden and rapid change from pupa to imago is often called metamorphosis, metamorphosis is really the whole series of changes that an insect undergoes from egg to adult. When emerging, the butterfly uses a liquid, sometimes called cocoonase, which softens the"
"base and (in most species) held folded back over the abdomen when perched. Dragonfly eyes occupy much of the animal's head, touching (or nearly touching) each other across the face. In damselflies, there is typically a gap in between the eyes. External morphology of Odonata Odonata (dragonflies and damselflies) are insects with an incomplete metamorphosis (hemimetabolous). The aquatic larva or nymph hatches from an egg, and develops through eight to seventeen instars before leaving the water and emerging as the winged adult or imago. The imago (adult stage) has a large head, well-developed, compound eyes, legs that facilitate catching prey"
"of the exoskeleton. Growth of the limbs and other parts normally covered by hard exoskeleton is achieved by transfer of body fluids from soft parts before the new skin hardens. A spider with a small abdomen may be undernourished but more probably has recently undergone ecdysis. Some arthropods, especially large insects with tracheal respiration, expand their new exoskeleton by swallowing or otherwise taking in air. The maturation of the structure and colouration of the new exoskeleton might take days or weeks in a long-lived insect; this can make it difficult to identify an individual if it has recently undergone ecdysis."
"inwardly concave, thus forming a central tube up which moisture is sucked. Suction takes place due to the contraction and expansion of a sac in the head. A specific example of the proboscis being used for feeding is in the species ""Deilephila elpenor"". In this species, the moth hovers in front of the flower and extends its long proboscis to attain its food. A few Lepidoptera species lack mouth parts and therefore do not feed in the imago. Others, such as the family Micropterigidae, have mouth parts of the chewing kind. The study of insect mouthparts was helpful for the"
"development (ametabolism), and the evolution of metamorphosis in insects is thought to have fuelled their dramatic radiation (1,2). Some early ametabolous ""true insects"" are still present today, such as bristletails and silverfish. Hemimetabolous insects include cockroaches, grasshoppers, dragonflies, and true bugs. Phylogenetically, all insects in the Pterygota undergo a marked change in form, texture and physical appearance from immature stage to adult. These insects either have hemimetabolous development, and undergo an incomplete or partial metamorphosis, or holometabolous development, which undergo a complete metamorphosis, including a pupal or resting stage between the larval and adult forms. A number of hypotheses have"
"In common with other members of the superorder Holometabola, Lepidoptera undergo complete metamorphosis, going through a four-stage life cycle: egg, larva / caterpillar, pupa / chrysalis, and imago (plural: ""imagines"") / adult. Lepidopterans range in size from a few millimetres in length, such as in the case of microlepidoptera, to a wingspan of many inches, such as the Atlas moth and the world's largest butterfly Queen Alexandra's birdwing. The body of an adult butterfly or moth (the imago) has three distinct divisions, called tagmata, connected at constrictions; these tagmata are the head, thorax, and abdomen. Adult lepidopterans have four wings:"
"over the abdomen. Their immature stages are aquatic fresh water forms (called ""naiads"" or ""nymphs""), whose presence indicates a clean, unpolluted environment. They are unique among insect orders in having a fully winged terrestrial adult stage, the subimago, which moults into a sexually mature adult, the imago. Mayflies ""hatch"" (emerge as adults) from spring to autumn, not necessarily in May, in enormous numbers. Some hatches attract tourists. Fly fishermen make use of mayfly hatches by choosing artificial fishing flies that resemble the species in question. One of the most famous English mayflies is ""Rhithrogena germanica"", the fisherman's ""March brown mayfly""."
"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"