Is Arthropoda. The animal world's largest one outline. Adult Tiqu separately, chest, abdomen part; head with a pair of antennae, generally with a pair of compound eyes and monocular 3; chest 3, there are three pairs of feet, wing 二 right. Adaptability and multiply rapidly. About four-fifths of the number of animal species. Intimate relationship with humans.
Sections, each separated by two soft, stretch film can be connected to the outer bone so that you can
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Mouthparts
Depending insect feeding methods, mouthparts can be divided into the following types. (1) chewing: the most primitive form of mouthparts, the upper lip, upper jaw, lower jaw, lower lip and tongue, is suitable for feeding to chew solid food, such as cockroaches, locusts mouthparts. It consists of five parts: (1-1) an upper lip, is located in front of the mouthpiece prevents leakage of food from the front. (1-2) palate (large jaw) pair located upper lip after party hard, with cutting teeth and molars, suitable for cutting, chewing food. (1-3) lower jaw (maxillary) pair located palate after the main function is to hold grip food. (1-4) a lower lip, located in the rearmost mouthparts to prevent food from leaking backwards. (1-5) a tongue, floor of the mouth between the jaws of the narrow wall projections, functional food of the Division taste and stirred. (2) sucking: Total called beak, the upper lip, lower lip, tongue, palate and a pair of one pair of jaw components. Can pierce the skin, can be injected into the blood-sucking or pathogens, such as the female mosquito mouthparts. The main suck animal blood and plant sap, requiring both a sucking fluid structure, but also a move to pierce the structure of plant tissues, and the difference between chewing mouthparts as follows: Upper and lower jaws (or a part of the jaw) special needle into an elongated opening; Lower lip extended into the beak; Fresh sinus formation of a strong suction mechanism. (3) lapping mouthparts: the lower jaw have been degraded, developed lower lip, tongue and upper lip package in which the lower end of the disc-shaped lips, licking suitable for food, such as houseflies mouthparts. (4) siphoning mouthparts: Lepidoptera adults possess, with an appearance as a strip of hair can be curled and stretched beak, suitable for deep sucking flower nectar bottom of the tube. (5) scraping mouthparts: specific to Diptera fly larvae (maggots). Features are: mouthparts very degraded, saw only a counterpart hook, use it to scratch food and then absorb the juice and solid debris. All retracted its head chest, the body all the front neck membrane. (6) The catch mouthparts: insect larvae NEUROPTERA of the unique, its most notable feature is the pair of jaw structure are composed of a pair of sucking, so there are double sucking mouthparts he said. (7) file mouthparts: the Thysanoptera thrips insects unique to the asymmetry of the various parts of its notable features. (8) barbed mouthparts lick: 1, long upper lip, pointed ends. 2, palate wider, was bladed, sharp ends can about the activities, together with the upper lip cut through animal or human skin relatively hard. 3, the outer jaw jaw and slender leaves form a hard stylet, which has been up and down tics make open stab wounds open. 4, lower lip hypertrophy soft, ends with a pair of fleshy lips, with a series of leading to the mouth of the lateral grooves on the front lip. 5, the tongue into the mouth of a relatively thin needle.
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Antenna
Wiry tentacles; filiform antennae; beaded antennae; serrated antennae; antennae toothed comb; pinnate (double comb-shaped) antennae; geniculate antennae; aristate antennae; ring hairy tentacles; club-shaped antennae; hammer (heads) antennae; antennae and other cheek like. Growth and development Hard shell so that the growth of insects is limited. To break this insect growth restriction, only in this way by molting. This process is actually the old shell insect faded, replaced by a new larger shell. Insect's life probably molt 5-15 times, its frequency varies due to insects, but they are determined. After faded leather, old housing is faded. But there are many insects, such as locusts, they will eat this one old shell. Adult and larvae appearance will vary greatly. During the deformation it is called metamorphosis. If the adults and larvae of the place is not the same, then the morphological differences between Talia will be very significant, such as dragonflies and mayflies. In contrast, when both the living environment similar, then their difference of form is not so obvious, such as insects and bugs locust Section Division. If the larvae develop into adults directly, it will be called incomplete metamorphosis. On the other hand, if the state between the two activities, there are still a standstill - pupae, then this will be called complete metamorphosis. In this development, the insects go through a cocoon, in a cocoon pupation process. There developmental type insects is almost bound to, such as thrips between the two, its last larval stage that is stationary. Or a snake head and hair winged purpose lacewing insects, their pupa cocoon before the adult is active, but before the last molt, they will find another place. Larval stages of insects, in fact, constantly eating stage, while adults usually only one task is to fertility and reproduction, in many cases no longer eat. Therefore larvae usually longer than the adult stage. The best example is the mayfly, their larval stage for several years, while the adult stage only one day. Beetle larvae for 3 years, adults live less than a few days. Many insect's life cycle is less than a year, but they have _set_ internal regulatory mechanisms, making it the adult in the same season each year appear. This is very important for them, because some insect larvae need to rely on a specific plant, this adjustment mechanism so that they can find their own place in the growth of the same time every year. Such as certain bees, they need to collect some specific flower pollen and nectar, in order to provide their offspring larval development of the necessary nutrients. So for them, the nectar of the flowering synchronization becomes very necessary. Insect resting will undergo a series of structural changes, and the stationary phase can occur at different stages of development. Many bees and bee pupae before 9 months will still close to satiation in a cocoon made good, and so, after a few years can only become pupa metamorphosis into adults. Many insects can alternate between generations in a year. Housefly very successful survival on Earth can even alternate between 15 generations a year. In contrast, some types of grasshoppers and dragonflies, you need five years of development period.
kunchong gang (huashi) Insects are one of the largest number of animal categories, but the fossils are relatively small. Insect fossils main purpose is to study the origin and evolution of all kinds of insects, mainly to explore the origins and the relationship between early insects evolved their different geological era of Modern insects; but can also make use of fossil clarify Palaeogeography for stratigraphic correlation, determine geologic time to provide evidence of ancient climate and depositional environment, so as to solve the production problems that exist in the formation. Morphological characteristics fossil insects body divided into head, chest, abdomen three parts, the head by a number of pieces of bone synthesis, it is the nerve center of parasites and grab food center. The head has one pair of antennae, one pair of upper jaw, one pair of jaws and a pair of lips, 3 pairs mouthparts. Antennae and mouthparts because of different types and adapt to different environments and have different types, which are an important basis for classification. Chest section before, during and after thoracic segments, is the center of the movement, and each section has a chest back, two side panels and a web; three thoracic segments have one pair of feet, before that in After foot; during and after thoracic segments each pair of wings, respectively, said the forewings and hind wings (such as dragonflies), and some hind wings degenerated into a balance bar (such as Diptera), and some completely wingless (eg Wingless subclass). Insect veins mainly by longitudinal veins and cross veins composed of longitudinal veins 6: leading edge pulse (C), Asia leading edge pulse (Sc), diameter veins (R), the pulse (M), cubital vein (Cu) , the caudal vein (A), each pulse can be divided into a number of offshoot (eg M □ ~ M □); cross veins distributed between the longitudinal veins, lowercase letters such as rm, intermediate form wing room. Longitudinal veins split wing surface, forming the leading edge region, Asia leading edge of the area, runoff area, in the vein area, elbow, hip region, the yoke area and so on. Changes in veins and vein zones complexity, evolution obviously become an important basis for classification. Fossil, it is more important. Abdominal segment variation evident from 5 to 12 composition, metabolism and reproduction is central. No intra-abdominal liver, salivary gland and heart there is a typical tracheal breathing animals. Each abdominal segment from the backplane and the web composed of sections of the connection between the film festival; each section on each side of the valve; the last section of the tail section, the anal opening in the ventral; abdominal end male mating, a female There ovipositor; at the end of larval abdominal appendages, after the disappearance of the adult, or the residue of a tail sting. Geohistory distribution of known insect fossil, first appeared in the Late Devonian, Devonian fossils previously found, has not yet been recognized, after all the times in both fossil, found in the base history insect fossils, generally points for the three large prosperous period: ① Late Paleozoic prosperous period (especially in the Carboniferous - Permian) During this period, the global climate was warm, moist, terrestrial plants grow a lot, wooded, rivers, swamps, lakes and large insects with such good natural environment , rapid development. This period is also an important coal-forming period, the coal-bearing strata in the basin or coastal marsh deposits often found abundant fossil insects, such as Asia, Oceania, Europe, North America, South Africa. Middle and Late Carboniferous insects, mainly in ancient fin (flapping wings can not be folded) Insects dominant; Permian insects evolved more by incomplete metamorphosis development of complete metamorphosis, ancient winged insects gradually moving towards a recession, some families, genera and species extinct, followed by the new fin (wings up and down, forward and backward movement, and can be folded affixed to the abdomen) rise insects and prosperous. In recent years, China's Shanxi Xiangning, Chengcheng, Pucheng, Hebei, Anhui and other places have been found in Carboniferous - Permian fossil insects. The extinction of species evolutionary provide evidence. ② Mesozoic prosperous period (in particular, the Late Triassic, early and middle Jurassic, Late Jurassic - Early Cretaceous) in this period, new winged insects is dominated by a wide range of complex changes, basically showing new insects face, and Paleozoic ancient winged insects dominated significantly different nature. Such as Australia and China in the Late Triassic, Liassic of Europe in the early Jurassic Jurassic ancient land of East Asia and the Late Jurassic - Early Cretaceous, it is important prosperous period of the Mesozoic insects. Chinese Mesozoic strata, widely distributed, occupy an important part of the ancient land of East Asia, not only rich in oil, natural gas, oil shale, coal and other minerals, and found a wide variety of insect fossils, including the famous Middle Jurassic World of "Yan Liao insect group" and Late Jurassic - Early Cretaceous, "Rehe insect group", the mass insect originated in northern China, west of Gansu, east of Shandong, Zhejiang, Henan south, to Mongolia Soviet Far East spread. The group common insect fossils have three proposed
Apterygota