Insects Fossil range: Early Devonian[1] (but see text) - Recent
Western honey bee (Order Hymenoptera)
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Subphylum: Hexapoda Class: Insecta Linnaeus, 1758

Insect anatomy
A- Head   B- Thorax   C- Abdomen

1. The Devonian is a geologic period and system of the Paleozoic era spanning from to  million years ago. Hymenoptera is one of the larger orders of Insects comprising the sawflies, Wasps Bees and Ants The name refers to Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " The subphylum Hexapoda (from the Greek for six legs) constitutes the largest (in terms of number of species grouping of Arthropods and includes the Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as, May 23 new style (13 May old style 1707 who laid the foundations for The book Systema Naturae was one of the major works of the Swedish doctor of medicine Carolus Linnaeus. antenna
2. Antennae (singular antenna) are paired Appendages connected to the front-most segments of Arthropods In Crustaceans they are ocelli (lower)
3. An ocellus (plural ocelli) is a type of Photoreceptor organ in animals ocelli (upper)
4. compound eye
5. brain (cerebral ganglia)
6. In Anatomy, a ganglion (pl ganglia) is a tissue mass. Neurology In neurological contexts ganglia are composed mainly of prothorax
7. The prothorax is the foremost of the three segments in the Thorax of an Insect, and bears the first pair of legs dorsal blood vessel
8. tracheal tubes (trunk with spiracle)
9. Many terrestrial Arthropods have evolved a closed Respiratory system composed of Spiracles, tracheae and Tracheoles to transport metabolic Spiracles are small openings on the surface of some Animals that usually lead to Respiratory systems In Elasmobranchs ( Sharks and mesothorax
10. The mesothorax is the middle of the three segments in the Thorax of an Insect, and bears the second pair of legs metathorax
11. The metathorax is the posterior of the three segments in the Thorax of an Insect, and bears the third pair of legs. forewing
12. Insect wings are outgrowths of the Insect Exoskeleton that enable insects to fly. hindwing
13. Insect wings are outgrowths of the Insect Exoskeleton that enable insects to fly. mid-gut (stomach)
14. dorsal blood vessel ("aorta")
15. ovary
16. hind-gut (intestine, rectum & anus)
17. The Hindgut (or epigaster) is the Posterior ( Caudal) part of the Alimentary canal. anus
18. oviduct
19. nerve chord (abdominal ganglia)
20. Malpighian tubes
21. The Malpighian tubule system is a type of Excretory and osmoregulatory system found in some Uniramia ( Insects and Myriapoda) tarsal pads
22. claws
23. tarsus
24. The arthropod leg is a form of jointed Appendage of Arthropods usually used for Walking. tibia
25. The arthropod leg is a form of jointed Appendage of Arthropods usually used for Walking. femur
26. The arthropod leg is a form of jointed Appendage of Arthropods usually used for Walking. trochanter
27. The arthropod leg is a form of jointed Appendage of Arthropods usually used for Walking. fore-gut (crop, gizzard)
28. thoracic ganglion
29. coxa
30. The arthropod leg is a form of jointed Appendage of Arthropods usually used for Walking. salivary gland
31. subesophageal ganglion
32. Insects The subesophageal ganglion of insects is composed of three pairs of fused Ganglia. mouthparts

Insects (Class Insecta) are a major group of arthropods and the most diverse group of animals on the Earth, with over a million described species—more than half of all known living organisms^[2][3]—with estimates of undescribed species as high as 30 million, thus potentially representing over 90% of the differing life forms on the planet. A class is the Taxonomic rank in the Biological classification of organisms in Biology below phylum and above order. Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. ^[4] Insects may be found in nearly all environments on the planet, although only a small number of species occur in the oceans, a habitat dominated by the other arthropod group of crustaceans. An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting

There are approximately 5,000 dragonfly species, 2,000 praying mantis, 20,000 grasshopper, 170,000 butterfly and moth, 120,000 fly, 82,000 true bug, 360,000 beetle, and 110,000 bee, wasp and ant species described to date. Odonata is an order of Insects encompassing dragonflies (Anisoptera and damselflies (Zygoptera The Insect order Mantodea or mantises consists of approximately 2000 species worldwide in Temperate and Tropical habitats of The Orthoptera (from the Greek ορθός orthos = "straight" and πτεрόν pteron = "wing" are an order of Insects Lepidoptera is an order of Insect that includes Moths and butterflies. True flies are Insects of the Order Diptera ( Greek: di = two and pteron = wing possessing a single pair of Hemiptera is an order of Insects comprising around 80000 Species of Cicadas Aphids Planthoppers Leafhoppers Beetles are the group of Insects with the largest number of known Species. Hymenoptera is one of the larger orders of Insects comprising the sawflies, Wasps Bees and Ants The name refers to Estimates of the total number of current species, including those not yet known to science, range from two million to fifty million, with newer studies favouring a lower figure of about six to ten million. ^[2][5][6] Adult modern insects range in size from a 0. 139 mm (0. 00547 in) fairyfly (Dicopomorpha echmepterygis) to a 55. Inches redirects here To see the Les Savy Fav album see Inches. Fairy flies are tiny egg parasites and there family Mymaridae is the family of the Alpatus Magnimius(0 Dicopomorpha echmepterygis is a parasitic wasp in the family Mymaridae. 5 cm (21. 9 in) long stick insect (Phobaeticus serratipes). "Phasmid" redirects here For the cloning vector used in genetics see Phagemid. The Stick insect Phobaeticus serratipes (formerly known as Pharnacia serratipes) is the longest known insect with one female specimen recorded ^[7] The heaviest documented insect was a Giant Weta of 70 g (2½ oz), but other possible candidates include the Goliath beetles Goliathus goliatus, Goliathus regius and Cerambycid beetles such as Titanus giganteus, though no one is certain which is truly the heaviest. Giant wetas are species of Weta in the genus Deinacrida of the family Anostostomatidae. For other uses of the words gram or gramme see Gram (disambiguation. This article is about the unit of mass For the unit of force see Pound-force. The Goliath beetles are among the largest insects on Earth, if measured in terms of size bulk and weight The Goliath beetles are among the largest insects on Earth, if measured in terms of size bulk and weight The Goliath beetles are among the largest insects on Earth, if measured in terms of size bulk and weight The longhorn beetles ( Cerambycidae; also known as long-horned beetles or more archaically longicorns) are a cosmopolitan family of Beetles The Titan beetle ( Titanus giganteus) is the largest known Beetle in the Amazon rainforest and one of the largest insect species in the world ^[7]

The study of insects (from Latin insectus, meaning "cut into sections") is called entomology, from the Greek εντομον, also meaning "cut into sections". Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Entomology (from Greek grc ἔντομος entomos, "that which is cut in pieces or engraved/segmented" hence "insect" and grc -λογία Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly ^[8]

Body structure

Insects possess segmented bodies supported by an exoskeleton, a hard outer covering made mostly of chitin. An exoskeleton is an external Skeleton that supports and protects an animal's body in contrast to the internal Endoskeleton of for example a Human. Chitin ( C 8 H 13 O 5 N)n (ˈkaɪtən is a long-chain Polymer of a N-acetylglucosamine The segments of the body are organized into three distinctive but interconnected units, or tagmata; a head, a thorax, and an abdomen. In Invertebrate Biology, a tagma (plural tagmata) is a specialized grouping of Arthropodan segments such as the The thorax is a division of an Animal 's body that lies between the head and the Abdomen. In Vertebrates such as Mammals the abdomen (belly constitutes the part of the body between the Thorax (chest and Pelvis. The head supports a pair of sensory antennae, a pair of compound eyes, one to three simple eyes ("ocelli") and three sets of variously modified appendages that form the mouthparts. Antennae (singular antenna) are paired Appendages connected to the front-most segments of Arthropods In Crustaceans they are An ocellus (plural ocelli) is a type of Photoreceptor organ in animals The mouthparts of Arthropods have evolved into a number of forms each adapted to a different style or mode of feeding The thorax has six segmented legs (one pair each for the prothorax, mesothorax and the metathorax segments making up the thorax) and two or four wings (if present in the species). In mathematics Six is the second smallest Composite number, its proper Divisors being 1, 2 and 3. The arthropod leg is a form of jointed Appendage of Arthropods usually used for Walking. Insect wings are outgrowths of the Insect Exoskeleton that enable insects to fly. The abdomen (made up of eleven segments some of which may be reduced or fused) has most of the digestive, respiratory, excretory and reproductive internal structures. Digestion is the breaking down of chemicals in the body into a form that can be absorbed In Animal physiology, respiration is the transport of Oxygen from the outside air to the cells within tissues and the transport of Carbon dioxide Excretion is the process of eliminating waste products of Metabolism and other non-useful materials

Nervous system

Their nervous system can be divided into a brain and a ventral nerve cord. The nervous system is a Network of specialized cells that communicate information about an animal's surroundings and itself The ventral nerve cords make up the Nervous system of some phyla of the Invertebrates particularly within the Nematodes Annelids and The head capsule (made up of six fused segments) has six pairs of ganglia. In Anatomy, a ganglion (pl ganglia) is a tissue mass. Neurology In neurological contexts ganglia are composed mainly of The first three pairs are fused into the brain, while the three following pairs are fused into a structure called the subesophageal ganglion. Insects The subesophageal ganglion of insects is composed of three pairs of fused Ganglia.

The thoracic segments have one ganglion on each side, which are connected into a pair, one pair per segment. This arrangement is also seen in the abdomen but only in the first eight segments. Many species of insects have reduced numbers of ganglia due to fusion or reduction. Some cockroaches have just six ganglia in the abdomen, whereas the wasp Vespa crabro has only two in the thorax and three in the abdomen. The European hornet Vespa crabro, commonly known simply as the " Hornet " is the largest European eusocial Wasp. And some, like the house fly Musca domestica, have all the body ganglia fused into a single large thoracic ganglion. The housefly (also house fly, house-fly or common housefly) Musca domestica, is the most common of all Flies

Respiration and circulation

Insect respiration is accomplished without lungs, using a system of internal tubes and sacs through which gases either diffuse or are actively pumped, delivering oxygen directly to the adjoining body tissues (see Invertebrate trachea). lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive Many terrestrial Arthropods have evolved a closed Respiratory system composed of Spiracles, tracheae and Tracheoles to transport metabolic Since oxygen is delivered directly, the circulatory system is not used to carry oxygen, and is therefore greatly reduced; it has no closed vessels (i. e. , no veins or arteries), consisting of little more than a single, perforated dorsal tube which pulses peristaltically, and in doing so helps circulate the hemolymph inside the body cavity. In the Circulatory system, a vein is a Blood vessel that carries Blood back toward the Heart (as opposed to Artery, a blood vessel Arteries are Blood vessels that carry blood away from the Heart. In the Esophagus After food is chewed into a bolus it is swallowed to move it into the esophagus Hemolymph or haemolymph is the Blood analogue used by all Arthropods and most Mollusks that have an Open circulatory system. Air is taken in through spiracles, openings on the sides of the abdomen. Spiracles are small openings on the surface of some Animals that usually lead to Respiratory systems In Elasmobranchs ( Sharks and

Exoskeleton

Most higher insects have two pairs of wings located on the second and third thoracic segments. Insect wings are outgrowths of the Insect Exoskeleton that enable insects to fly. Insects are the only invertebrates to have developed flight, and this has played an important part in their success. An invertebrate is an Animal lacking a Vertebral column. The group includes 98% of all animal Species — all animals except those in the Chordate Insects are the only group of Invertebrates known to have evolved flight The winged insects, and their wingless relatives, make up the subclass Pterygota. Pterygota is a subclass of Insects that includes the winged insects Insect flight is not very well understood, relying heavily on turbulent aerodynamic effects. Insects are the only group of Invertebrates known to have evolved flight The primitive insect groups use muscles that act directly on the wing structure. The more advanced groups making up the Neoptera have foldable wings and their muscles act on the thorax wall and power the wings indirectly. Neoptera is a classification group that includes almost all the winged Insects specifically those that can flex their wings over their abdomens These muscles are able to contract multiple times for each single nerve impulse, allowing the wings to beat faster than would ordinarily be possible (see insect flight). Insects are the only group of Invertebrates known to have evolved flight

Their outer skeleton, the cuticle, is made up of two layers; the epicuticle which is a thin and waxy water resistant outer layer and contains no chitin, and another layer under it called the procuticle. The epicuticle is the outermost portion of the Exoskeleton of an Insect (and various other Arthropods; its exact composition and structure may differ somewhat The procuticle is the major portion of the Exoskeleton of an Insect (and various other Arthropods; its exact composition and structure may differ somewhat This is chitinous and much thicker than the epicuticle and has two layers, the outer being the exocuticle while the inner is the endocuticle. The tough and flexible endocuticle is built from numerous layers of fibrous chitin and proteins, criss-crossing each others in a sandwich pattern, while the exocuticle is rigid and sclerotized. A sclerite ( Greek skleros meaning " hard " is a hardened body part The exocuticle is greatly reduced in many soft-bodied insects, especially the larval stages (e. A larva ( Latin; plural larvae) is a juvenile form of Animal with indirect development, undergoing Metamorphosis (for example g. , caterpillars). Caterpillars are the Larval form of a member of the order Lepidoptera (the Insect order comprising butterflies and Moths

Development

Hoverflies mating in flight

Most insects hatch from eggs, but some are ovoviviparous or viviparous, and all undergo a series of moults as they develop and grow in size. In most Birds and Reptiles an egg ( Latin ovum) is the Zygote, resulting from Fertilization of the Ovum. Ovoviviparous Animals develop within eggs that remain within the mother's body up until they hatch or are about to hatch A viviparous Animal is an animal employing vivipary: the embryo develops inside the body of the mother as opposed to outside in an egg ( Ovipary Ecdysis is the Molting of the Cuticula in Arthropods and related groups ( Ecdysozoa) This manner of growth is necessitated by the inelastic exoskeleton. Moulting is a process by which the individual escapes the confines of the exoskeleton in order to increase in size, then grows a new and larger outer covering. In some insects, the young are called nymphs and are similar in form to the adult except that the wings are not developed until the adult stage. This is called incomplete metamorphosis and insects showing this are termed hemimetabolous. Metamorphosis is a Biological process by which an Animal physically develops after Birth or hatching involving a conspicuous and relatively Hemimetabolism or hemimetaboly, also called incomplete metamorphosis, is a term used to describe the mode of development of certain insects that includes Holometabolous insects show complete metamorphosis, which distinguishes the Endopterygota and includes many of the most successful insect groups. Holometabolism, also called complete metamorphism, is a term applied to insect groups to describe the specific kind of insect development which includes four The Endopterygota, also known as Holometabola, are Insects of the subclass Pterygota which go through distinctive Larval Pupal In these species, an egg hatches to produce a larva, which is generally worm-like in form, and can be divided into five different forms; eruciform (caterpillar-like), scarabaeiform (grublike), campodeiform (elongated, flattened, and active), elateriform (wireworm-like) and vermiform (maggot-like). A larva ( Latin; plural larvae) is a juvenile form of Animal with indirect development, undergoing Metamorphosis (for example The larva grows and eventually becomes a pupa, a stage marked by reduced movement and foten sealed within a cocoon. A pupa ( Latin pupa for doll pl pupae or pupas) is the life stage of some Insects undergoing transformation A pupa ( Latin pupa for doll pl pupae or pupas) is the life stage of some Insects undergoing transformation There are three types of pupae; obtect (the pupa is compact with the legs and other appendages enclosed), exarate (where the pupa has the legs and other appendages free and extended) and coarctate (where the pupa develops inside the larval skin). In the pupal stage, the insect undergoes considerable change in form to emerge as an adult, or imago. In Biology, the imago is the last stage of development of an Insect, after the last Ecdysis of an incomplete metamorphosis, or after emergence Butterflies are an example of an insect that undergoes complete metamorphosis. Some insects have even evolved hypermetamorphosis. Hypermetamorphosis is a kind of complete metamorphosis in which the different Larval Instars represent two or more different forms of larva

Some insects (parastic wasps) show polyembryony where a single fertilized egg can divide into many and in some cases thousands of separate embryos. Polyembryony is the phenomenon of two or more Embryos developing from a single fertilized egg (in humans Identical twins) Other developmental and reproductive variations include haplodiploidy, polymorphism, paedomorphosis (metathetely and prothetely), sexual dimorphism, parthenogenesis and more rarely hermaphroditism. The haplodiploid sex-determination system determines the sex of the offspring of many Hymenopterans ( Bees Ants and Wasps, and coleopterans ( Polymorphism in biology occurs when two or more clearly different Phenotypes exist in the same population of a species — in other words the occurrence of more than one In Developmental biology, pedomorphosis (also spelled paedomorphosis) or juvenification is a phenotypic and/or genotypic change in Sexual dimorphism is the systematic difference in form between individuals of different Sex in the same Species. Parthenogenesis (from the Greek παρθένος parthenos, "virgin" + γένεσις genesis, "creation" is an asexual form A hermaphrodite is an organism having both male and female reproductive organs

Senses and communication

A robberfly with its prey, a hoverfly

Many insects possess very sensitive and/or specialized organs of perception. Insects in the Diptera family Asilidae are commonly called robber flies. Flies in the Diptera family Syrphidae are commonly known as hoverflies, flower flies, or Syrphid flies. Senses are the physiological methods of Perception. The senses and their operation classification and theory are overlapping topics studied by a variety of fields Some insects such as bees can perceive ultraviolet wavelengths, or detect polarized light, while the antennae of male moths can detect the pheromones of female moths over distances of many kilometres. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Polarization ( ''Brit'' polarisation) is a property of Waves that describes the orientation of their oscillations Antennae (singular antenna) are paired Appendages connected to the front-most segments of Arthropods In Crustaceans they are A pheromone (from Greek φέρω phero "to bear" + ‘ορμόνη " Hormone " is a Chemical that triggers a natural There is a pronounced tendency for there to be a trade-off between visual acuity and chemical or tactile acuity, such that most insects with well-developed eyes have reduced or simple antennae, and vice-versa. There are a variety of different mechanisms by which insects perceive sound, and it is by no means universal; the general pattern, however, is that if an insect can produce sound, then it can also hear sound, though the range of frequencies they can hear is often quite narrow (and may in fact be limited to only the frequency that they themselves produce). Some nocturnal moths can perceive the ultrasonic emissions of bats, a mechanism which helps them avoid predation. Certain predatory and parasitic insects can detect the characteristic sounds made by their prey/hosts. Bloodsucking insects have special sensory structures that can detect infrared emissions, and use them to home in on their hosts. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of

Sensillae: sensory structures on insects

A few such insects also have a well-developed number sense, among the solitary wasps that provision with a single species of prey. The mother wasp lays her eggs in individual cells and provides each egg with a number of live caterpillars on which the young feed when hatched. Some species of wasp always provide five, others twelve, and others as high as twenty-four caterpillars per cell. The number of caterpillars is different among species, but it is always the same for each sex of larvae. The male solitary wasp in the genus Eumenes is smaller than the female, so the mother of one species supplies him with only five caterpillars; the larger female receives ten caterpillars in her cell. Eumenes is the Type genus of the subfamily Eumeninae (" Potter wasps quot of Vespidae. She can in other words distinguish between both the numbers five and ten in the caterpillars she is providing and which cell contains a male or a female.

Light production and vision

A few insects, such as members of the families Poduridae and Onychiuridae (Collembola), Mycetophilidae (Diptera), and the beetle families Lampyridae, Phengodidae, Elateridae and Staphylinidae are bioluminescent. Mycetophilidae is a family of very small flies, forming the bulk of those species known as Fungus gnats There are approximately 3000 described species in 150 genera FireFly is the second single by Essex Alternative rock band InMe. The Beetle family Phengodidae is known also as glowworm beetles, whose Larvae are known as Glowworms. The family Elateridae is commony called click beetles (or "typical click beetles" to distinguish them form the related Cerophytidae and The rove beetles are a large family ( Staphylinidae) of Beetles primarily distinguished by their short Elytra that leave more than half of their Bioluminescence' is the production and emission of Light by a living Organism as the result of a chemical reaction during which chemical energy is converted The most familiar group are the fireflies, beetles of the family Lampyridae. Some species are able to control this light generation to produce flashes. The function varies with some species using them to attract mates, while others use them to lure prey. Cave dwelling larvae of Arachnocampa (Mycetophilidae, Fungus gnats) glow to lure small flying insects into sticky strands of silk. Arachnocampa is a genus of four Fungus gnat species which are in their Larval stage Glowworms They are found mostly in New Zealand ^[9] Some fireflies of the genus Photuris mimic the flashing of female Photinus species to attract males of that species, which are then capture and devoured. Biological mimicry occurs when a group of organisms the mimics, have This article is about the 4th century bishop Photinus For the Firefly Beetle Genus, see Photinus (beetle. ^[10] The colours of emitted light vary from dull blue (Orfelia fultoni, Mycetophilidae) to the familiar greens and the rare reds (Phrixothrix tiemanni, Phengodidae). ^[11]

Most insects except some species of cave dwelling crickets are able to perceive light and dark. Many species have acute vision capable of detecting minute movements. The eyes include simple eyes or ocelli as well as compound eyes of varying sizes. An ocellus (plural ocelli) is a type of Photoreceptor organ in animals Many species are able to detect light in the infrared, ultraviolet as well as the visible light wavelengths. Colour vision has been demonstrated in many species.

Bottle flies are considered "pests"

Sound production and hearing

Insects were the earliest organisms to produce sounds and to sense them. Soundmaking in insects is achieved mostly by mechanical action of appendages. In the grasshoppers and crickets this is achieved by stridulation. Grasshoppers are Insects of the suborder Caelifera in the order Orthoptera. Stridulation is the act of producing Sound by rubbing together certain body parts The cicadas have the loudest sounds among the insects and have special modifications to their body and musculature to produce and amplify sounds. A cicada is an Insect of the order Hemiptera, suborder Auchenorrhyncha, in the superfamily Cicadoidea, with large eyes wide apart on the Some species such as the African cicada, Brevisana brevis have been measured at 106. A cicada is an Insect of the order Hemiptera, suborder Auchenorrhyncha, in the superfamily Cicadoidea, with large eyes wide apart on the 7 decibels at a distance of 50 cm (20 in). The decibel ( dB) is a logarithmic unit of measurement that expresses the magnitude of a physical quantity (usually power or intensity relative to ^[7] Some insects, such as the hawk moths and Hedylid butterflies, can hear ultrasound and take evasive action when they sense detection by bats. For a complete species list of this family see the Sphingidae species list. Hedylidae, the "American moth-butterflies" is a family of Insects in the Lepidopteran order representing the superfamily Some moths produce ultrasound clicks and these were earlier thought to have a role in jamming the bat echolocation, but it was subsequently found that these are produced mostly by unpalatable moths to warn bats, just as warning colourations are used against predators that hunt by sight. ^[12] These calls are also made by other moths involved in mimicry. Biological mimicry occurs when a group of organisms the mimics, have ^[13]

Very low sounds are also produced in various species of Neuroptera, Lepidoptera (butterflies and moths), Coleoptera and Hymenoptera produced by the mechanical actions of movement often aided by special microscopic stridulatory structures. Lepidoptera is an order of Insect that includes Moths and butterflies. A butterfly is an Insect of the order Lepidoptera. Like all Lepidoptera butterflies are notable for their unusual life cycle with a Beetles are the group of Insects with the largest number of known Species. Hymenoptera is one of the larger orders of Insects comprising the sawflies, Wasps Bees and Ants The name refers to

Most sound-making insects also have tympanal organs that can perceive airborne sounds. A Tympanal organ is a hearing organ in Insects, consisting of a membrane ( tympanum) stretched across a frame backed by an air sac Most insects are also able to sense vibrations transmitted by the substrate. Communication using substrate-borne vibrational signals is more widespread among insects because of the size constraints in producing air-borne sounds. Vibration refers to mechanical Oscillations about an equilibrium point. ^[14] Insects cannot effectively produce low-frequency sounds, and high-frequency sounds tend to disperse more in a dense environment (such as foliage), so insects living in such environments communicate primarily using substrate-borne vibrations. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. ^[15] The mechanisms of production of vibrational signals are just as diverse as those for producing sound in insects.

Some species use vibrations for communicating within members of the same species, such as to attract mates as in the songs of the shield bug Nezara viridula^[16] while it can also be used to communicate between entirely different species, such as between ants and myrmecophilous lycaenid caterpillars. Shield bug and Stink bug (or shieldbug and stinkbug) are common names applied to various insects of the Hemiptera order (the ^[17]

The Madagascar hissing cockroach has the ability to press air through the spiracles to make a hissing noise, and the Death's-head Hawkmoth makes a squeaking noise by forcing air out of their pharynx. The Madagascar hissing cockroach ( Gromphadorhina portentosa) also known as Hissing roach or simply Hisser, is one of the largest species of Cockroach The name Death's-head Hawkmoth refers to any one of the three species ( A The pharynx (plural pharynges) is the part of the Neck and Throat situated immediately Posterior to (behind the Mouth and Nasal

Chemical communication

In addition to the use of sound for communication, a wide range of insects have evolved chemical means for communication. These chemicals, termed semiochemicals, are often derived from plant metabolites include those meant to attract, repel and provide other kinds of information. A semiochemical (semeon means a signal in Greek is a generic term used for a chemical substance or mixture that carries a message While some chemicals are targeted at individuals of the same species, others are used for communication across species. The use of scents is especially well known to have developed in social insects.

Social behaviour

A termite mound made by the cathedral termite

Social insects, such as the termites, ants and many bees and wasps, are the most familiar species of eusocial animal. Eusociality ( Greek eu: "good" + "social" is a term used for the highest level of social organization in a hierarchical classification The termites are a group of Social Insects usually classified at the taxonomic rank of order Isoptera (but see also taxonomy Ants are social Insects of the family Formicidae and along with the related families of Wasps and Bees belong to the order Bees are flying Insects closely related to Wasps and Ants Bees are a Monophyletic lineage within the superfamily Apoidea A wasp is any Insect of the order Hymenoptera and suborder Apocrita that is neither a Bee nor Ant. Eusociality ( Greek eu: "good" + "social" is a term used for the highest level of social organization in a hierarchical classification They live together in large well-organized colonies that may be so tightly integrated and genetically similar that the colonies of some species are sometimes considered superorganisms. A superorganism is an Organism consisting of many organisms This is usually meant to be a Social unit of eusocial animals where Division of labour It is sometimes argued that the various species of honey bee are the only invertebrates (and indeed one of the few non-human groups) to have evolved a system of abstract symbolic communication (i. This article refers collectively to all true honey bees for the "common" domesticated honey bee see European honey bee Honey bees e. , where a behaviour is used to represent and convey specific information about something in the environment), called the "dance language" - the angle at which a bee dances represents a direction relative to the sun, and the length of the dance represents the distance to be flown. Honey bees learn and communicate in order to find food sources and for other means

Only those insects which live in nests or colonies demonstrate any true capacity for fine-scale spatial orientation or "homing" - this can be quite sophisticated, however, and allow an insect to return unerringly to a single hole a few millimetres in diameter among a mass of thousands of apparently identical holes all clustered together, after a trip of up to several kilometres' distance, and (in cases where an insect hibernates) as long as a year after last viewing the area (a phenomenon known as philopatry). For the ability of certain operating systems see Hibernate (OS feature Hibernation is a state of inactivity and metabolic depression In Animal Behaviour philopatry is the tendency of a migrating animal to return to a specific location in order to breed or feed A few insects migrate, but this is a larger-scale form of navigation, and often involves only large, general regions (e. Insect migration is the seasonal movement of Insects particularly those by species of dragonflies, Beetles butterflies and Moths Navigation is the process of reading and controlling the movement of a craft or vehicle from one place to another g. , the overwintering areas of the Monarch butterfly). The monarch ( Danaus plexippus) is a Milkweed butterfly ( Subfamily Danainae in the family Nymphalidae.

Care of young

Most insects lead short lives as adults, and rarely interact with one another except to mate, or compete for mates. A small number exhibit some form of parental care, where they will at least guard their eggs, and sometimes continue guarding their offspring until adulthood, and possibly even actively feeding them. Parenting is the process of raising and educating a Child from birth, or before until Adulthood In the case of humans it is usually Another simple form of parental care is to construct a nest (a burrow or an actual construction, either of which may be simple or complex), store provisions in it, and lay an egg upon those provisions. The adult does not contact the growing offspring, but it nonetheless does provide food. This sort of care is typical of bees and various types of wasps.

Locomotion

Flight

Main article: Insect flight

Insects are the only group of invertebrates to have developed flight. Insects are the only group of Invertebrates known to have evolved flight The evolution of insect wings has been a subject of debate. Some proponents suggest that the wings are para-notal in origin while others have suggested they are modified gills. In the Carboniferous age, some of the Meganeura dragonflies had as much as a 50 cm (20 in) wide wingspan. The appearance of gigantic insects has been found to be consistent with high atmospheric oxygen. The percentage of oxygen in the atmosphere found from ice core-samples was as high as 35% compared to the current 21%. The respiratory system of insects constrains their size, however the high oxygen in the atmosphere allowed larger sizes. ^[18] The largest flying insects today are much smaller and include several moth species such as the Atlas moth and the White Witch (Thysania agrippina). The Atlas moth ( Attacus atlas) is a large saturniid moth found in the tropical and subtropical forests of Southeast Asia, southern China, common

Insect flight has been a topic of great interest in aerodynamics due partly to the inability of steady-state theories to explain the lift generated by the tiny wings of insects.

In addition to powered flight, many of the smaller insects are also dispersed by winds. These include the aphids which are often transported long distances by low-level jet streams. ^[19]

Walking

Many adult insects use six legs for walking and have adopted a tripedal gait. Tripedal (from the Latin tri = three + ped = foot is the term used for (or would be used for any Animal that stands on Three The tripedal gait allows for rapid walking whilst always having a stable stance and has been studied extensively in cockroaches. Cockroaches (or simply "roaches" are Insects of the order Blattaria. The legs are used in alternate triangles touching the ground. For the first step the middle right leg and the front and rear left legs are in contact with the ground and move the insect forward, whilst the front and rear right leg and the middle left leg are lifted and moved forward to a new position. When they touch the ground to form a new stable triangle the other legs can be lifted and brought forward in turn and so on.

The purest form of the tripedal gait is seen in insects moving at speed. However, this type of locomotion is not rigid and insects can adapt a variety of gaits; for example, when moving slowly, turning, or avoiding obstacles, four or more feet may be touching the ground. Insects can also adapt their gait to cope with the loss of one or more limbs.

Cockroaches are amongst the fastest insect runners and at full speed actually adopt a bipedal run to reach a high velocity in proportion to their body size. Cockroaches (or simply "roaches" are Insects of the order Blattaria. As Cockroaches move extremely rapidly, they need recording at several hundred frames per second to reveal their gait. Cockroaches (or simply "roaches" are Insects of the order Blattaria. More sedate locomotion is also studied by scientists in stick insects Phasmatodea. "Phasmid" redirects here For the cloning vector used in genetics see Phagemid.

A few insects have evolved to walk on the surface of the water, especially the bugs of the family, Gerridae, also known as water striders. The family Gerridae contains insects commonly known as water striders, water bugs, magic bugs, pond skaters, skaters, skimmers A few species of ocean-skaters in the genus Halobates even live on the surface of open oceans, a habitat that has few insect species.

Insect walking is of particular interest as an alternative form of locomotion to the use of wheels for robots (Robot locomotion). Robot locomotion is the study of how to design Robot appendages and control mechanisms to allow robots to move fluidly and efficiently

Swimming

The backswimmer Notonecta glauca underwater, showing the paddle like hindleg adaptation

A large number of insects live either parts or the whole of their lives underwater. Notonectidae is a cosmopolitan family of aquatic insects in the order Hemiptera, commonly called backswimmers because they swim upside down In many of the more primitive orders the immature stages are aquatic while some other groups have aquatic adults as well. ^[20]

Many of these species have adaptations to help in locomotion under water. The water beetles and water bugs have legs adapted into paddle like structures. Dragonfly naiads, use jet propulsion, forcibly expelling water out of the rectal chamber. ^[21]

Some species like the water striders are capable of walking on the surface of water. The family Gerridae contains insects commonly known as water striders, water bugs, magic bugs, pond skaters, skaters, skimmers They can do this because their claws are not at the tips of the legs as in most insects, but recessed in a special groove further up the leg; this prevents the claws from piercing the water's surface film. ^[20] Other insects such as the Rove beetle Stenus are known to emit salivary secretions that reduce surface tension making it possible for them to move on the surface of water by Marangoni propulsion (also known by the German term Entspannungsschwimmen). The rove beetles are a large family ( Staphylinidae) of Beetles primarily distinguished by their short Elytra that leave more than half of their The Marangoni effect (sometimes also called the Gibbs-Marangoni effect) is the mass transfer on or in a liquid layer due to Surface tension differences ^[22][23]

Species that are submerged also have adaptations to aid in respiration. Many larval forms have gills that can extract oxygen dissolved in water, while others need to rise to the water surface to replenish air supplies which may be held or trapped in special structures. ^[20]

Evolution

Main article: Insect evolution

The relationships of insects to other animal groups remain unclear. The relationships of Insects to other animal groups remain unclear Although more traditionally grouped with millipedes and centipedes, evidence has emerged favoring closer evolutionary ties with the crustaceans. eVolution is the third Album by eLDee, it was due to be released in 2008 In the Pancrustacea theory insects, together with Remipedia and Malacostraca, make up a natural clade. Pancrustacea is a proposed Taxon, comprising all Crustaceans and hexapods   Remipedia is a class of blind Crustaceans found in deep caves connected to salt water in Australia and the Caribbean Sea. The Malacostraca (Greek "soft shell" are the largest class of Crustaceans and include most of the animals that non-experts recognize as crustaceans including A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor

Other terrestrial arthropods, such as centipedes, millipedes, scorpions and spiders, are sometimes confused with insects since their body plans can appear similar, sharing (as do all arthropods) a jointed exoskeleton. Centipedes (from Latin prefix centi-, "hundred" and Greek ποδός podos, " Foot " are Millipedes (Class Diplopoda, previously also known as Chilognatha are Arthropods that have two pairs of legs per segment (except for the first segment behind Scorpions are eight-legged Carnivorous Arthropods They are members of the order Scorpiones within the class Arachnida. Spiders are Predatory Invertebrate Animals that have two body segments, eight legs no chewing mouth parts and no wings However upon closer examination their features differ significantly; most noticeably they do not have the six legs characteristic of adult insects.

The higher level phylogeny of the arthropods continues to be a matter of debate and research.

The oldest definitive insect fossil is the Devonian Rhyniognatha hirsti, from the 396 million year old^[25] Rhynie chert. The Devonian is a geologic period and system of the Paleozoic era spanning from to  million years ago. The Rhynie chert is an Early Devonian Lagerstätte found near the village of Rhynie, Aberdeenshire, Scotland, containing exceptionally This species already possessed dicondylic mandibles, a feature associated with winged insects, suggesting that wings may already have evolved at this time. Thus, the first insects probably appeared earlier, in the Silurian period. The Silurian is a geologic period and system that extends from the end of the Ordovician period about 443 ^[1]

The origins of insect flight remain obscure, since the earliest winged insects currently known appear to have been capable fliers. Insects are the only group of Invertebrates known to have evolved flight Some extinct insects had an additional pair of winglets attaching to the first segment of the thorax, for a total of three pairs. So far, there is nothing that suggests that the insects were a particularly successful group of animals before they got their wings.

Late Carboniferous and Early Permian insect orders include both several current very long-lived groups and a number of Paleozoic forms. The Pennsylvanian is a subperiod of the Carboniferous period lasting from roughly   to  Ma (million years ago During this era, some giant dragonfly-like forms reached wingspans of 55 to 70 cm, (22-28 in) making them far larger than any living insect. This gigantism may have been due to higher atmospheric oxygen levels that allowed increased respiratory efficiency relative to today. The lack of flying vertebrates could have been another factor.

Most extant orders of insects developed during the Permian era that began around 270 million years ago. The Permian is a geologic period and system that extends from 299 Many of the early groups became extinct during the Permian-Triassic extinction event, the largest mass extinction in the history of the Earth, around 252 million years ago. The Permian–Triassic (P–Tr extinction event, informally known as the Great Dying, was an Extinction event that occurred, and 70 percent of terrestrial

The remarkably successful Hymenopterans appeared in the Cretaceous but achieved their diversity more recently, in the Cenozoic. The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of The Cenozoic (also Caenozoic or Cainozoic) Era (ˌsiːnəˈzoʊɪk/ /ˌsɛn- (meaning "new life" ( Greek ( kainos) "new" A number of highly-successful insect groups evolved in conjunction with flowering plants, a powerful illustration of co-evolution. The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group In a broad sense biological co-evolution is "the change of a biological object triggered by the change of a related object"

Many modern insect genera developed during the Cenozoic; insects from this period on are often found preserved in amber, often in perfect condition. The Cenozoic (also Caenozoic or Cainozoic) Era (ˌsiːnəˈzoʊɪk/ /ˌsɛn- (meaning "new life" ( Greek ( kainos) "new" Amber is Fossil tree Resin, which is appreciated for its color and beauty Such specimens are easily compared with modern species. The study of fossilized insects is called paleoentomology.

Coevolution

See also: Coevolution

Insects were among the earliest terrestrial herbivores and acted as major selection agents on plants. In a broad sense biological co-evolution is "the change of a biological object triggered by the change of a related object" Plants evolved chemical defenses against this herbivory and the insects in turn evolved mechanisms to deal with plant toxins. Plant defense against herbivory or host-plant resistance (HPR includes a range of Adaptations evolved Many insects make use of these toxins to protect themselves from their predators. And such insects advertise their toxicity using warning colours. This successful evolutionary pattern has also been utilized by mimics. Biological mimicry occurs when a group of organisms the mimics, have Over time, this has led to complex groups of co-evolved species. In a broad sense biological co-evolution is "the change of a biological object triggered by the change of a related object" Conversely, some interactions between plants and insects are beneficial (see pollination), and coevolution has led to the development of very specific mutualisms in such systems. Pollination in angiosperms and Gymnosperms is the process that transfers pollen grains, which contain the male Gametes (sperm to where the female Mutualism is a Biological interaction between individuals of two different Species, where both individuals derive a fitness benefit for example increased

Classification

Traditional morphology-based systematics has included in the subphylum Hexapoda four groups - Insects (Ectognatha), springtails (Collembola), Protura and Diplura, the latter three being grouped together as Entognatha on the basis of internalized mouthparts. In life a subphylum is a Taxonomic rank intermediate between phylum and superclass. The subphylum Hexapoda (from the Greek for six legs) constitutes the largest (in terms of number of species grouping of Arthropods and includes the Springtails ( Collembola) form the largest of the three lineages of modern hexapods that are no longer considered Insects (the other two are the The Protura, or proturans, and sometimes nicknamed coneheads are an order of hexapods previously regarded as insects and sometimes treated as The order Diplura is one of the four groups of hexapods, alongside Insects Springtails and Protura. The Entognatha is a class of Ametabolous Arthropods which together with Insects makes up the hexapods. Supraordinal relationships have undergone numerous changes with the advent of cladistic methods and genetic data. Cladistics is the hierarchical classification of Species based on evolutionary ancestry A recent hypothesis is that Hexapoda is polyphyletic, with the entognath classes having separate evolutionary histories from Insecta.

As many of the traditional morphology-based taxa have been shown to be paraphyletic, it is best to avoid using terms such as subclass, superorder and infraorder and instead focus on monophyletic groupings. This article is about the taxonomic rank for the sequence of species in a taxonomic list see Taxonomic order In scientific classification used This article is about the taxonomic rank for the sequence of species in a taxonomic list see Taxonomic order In scientific classification used The following list represents the best supported monophyletic groupings for the Insecta.

† signifies an extinct taxon.

Apterygota

• Monura †

Monocondylia

• Archaeognatha=Microcoryphia (bristletails)

Dicondylia

• Thysanura=Zygentoma (silverfish)

Pterygota

Paleoptera

• Ephemeroptera (mayflies)
• Palaeodictyoptera †
• Megasecoptera †
• Archodonata †
• Diaphanopterodea †
• Protodonata=Meganisoptera †
• Protanisoptera †
• Triadophlebioptera †
• Protozygoptera=Archizygoptera †
• Odonata (dragonflies, damselflies)

Orthetrum caledonicum, the Blue Skimmer dragonfly

Neoptera

Polyneoptera

• Caloneurodea †
• Titanoptera †
• Protorthoptera †
• Plecoptera (stoneflies)
• Embiidina=Embioptera (webspinners)
• Zoraptera (angel insects)
• Dermaptera (earwigs)
• Orthoptera (grasshoppers, crickets, katydids)
• Phasmatodea (stick insects)
• Notoptera (ice-crawlers & gladiators)
• Blattaria (cockroaches)

• Isoptera (termites - included in Blattaria)

• Mantodea (mantids)

A Chinese Mantis. The name Apterygota is sometimes applied to a subclass of small agile Insects distinguished from other insects by their lack of wings in the present and in their Archaeognatha is an order of wingless Insects also known as jumping bristletails. The insects of the order Thysanura, usually referred to as Silverfish, may also be called bristletails, from their three long caudal filaments Pterygota is a subclass of Insects that includes the winged insects The name Palaeoptera has been traditionally applied to those primitive groups of Winged insects (most of them extinct that lacked the ability to fold the wings back over Mayflies are Insects which belong to the Order Ephemeroptera (from the Greek ephemeros = "short-lived" pteron The Palaeodictyoptera are an extinct order of medium-sized to very large primitive Palaeozoic paleopterous insects characterised by beak-like mouthparts similarity between Megasecoptera is a paleozoic Insect order There were 22 families of megasecopterans with only about 35 known genera The Diaphanopterodea or Paramegasecoptera are an extinct order of moderate to large-sized Palaeozoic insects The Protodonata or Meganisoptera are an extinct order of very large to gigantic Palaeozoic ( Late Carboniferous to Late Permian) insects similar in appearance Odonata is an order of Insects encompassing dragonflies (Anisoptera and damselflies (Zygoptera The Blue Skimmer, Orthetrum caledonicum, is a common Australian Dragonfly. Neoptera is a classification group that includes almost all the winged Insects specifically those that can flex their wings over their abdomens The Protorthoptera are an extinct order of Palaeozoic insects and represent a Wastebasket taxon and Paraphyletic assemblage of basal Neoptera Plecoptera are an order of Insects commonly known as stoneflies. Webspinners or embiids ( order Embioptera) are a small group of mostly Tropical and Subtropical Insects classified The Insect order Zoraptera contains one family ( Zorotypidae) which in turn contains one extant Genus, Zorotypus Earwigs is the common name given to the Insect order Dermaptera characterized by membranous wings folded underneath short leathery forewings The Orthoptera (from the Greek ορθός orthos = "straight" and πτεрόν pteron = "wing" are an order of Insects "Phasmid" redirects here For the cloning vector used in genetics see Phagemid. The insect order Notoptera, a group first proposed in 1915 has been largely unused since its original conception but in the most recent classification of the lineage of insects that Cockroaches (or simply "roaches" are Insects of the order Blattaria. The termites are a group of Social Insects usually classified at the taxonomic rank of order Isoptera (but see also taxonomy The Insect order Mantodea or mantises consists of approximately 2000 species worldwide in Temperate and Tropical habitats of The Chinese mantis ( Tenodera sinensis) is a species of Praying mantis.

Paraneoptera

• Psocodea (booklice, barklice)

• Mallophaga (chewing lice - in Psocodea)
• Anoplura (sucking lice - in Psocodea)

• Thysanoptera (thrips)
• Hemiptera (true bugs, aphids, cicadas)

A Yellowjacket wasp. Chewing lice ( Mallophaga) have nearly 3000 species and represent the larger of the two traditional suborders of Lice (cf Sucking lice ( Anoplura) have around 500 Species and represent the smaller of the two traditional suborders of Lice. Hemiptera is an order of Insects comprising around 80000 Species of Cicadas Aphids Planthoppers Leafhoppers Yellowjacket or yellow-jacket is the Common name in North America for predatory Wasps of the genera Vespula and

Endopterygota=Holometabola

• Glosselytrodea †
• Miomoptera †
• Hymenoptera (wasps, bees, ants)
• Coleoptera (beetles)
• Strepsiptera (twisted-winged parasites)

Neuropterida

• Raphidioptera (snakeflies)
• Megaloptera (alderflies, dobsonflies)
• Neuroptera (lacewings, antlions)

Antliophora/Mecopteroidea

• Mecoptera (scorpionflies, hangingflies)

• Siphonaptera (fleas - in Mecoptera)

A Syrphid fly on a Grape hyacinth

• Diptera (true flies)
• Protodiptera †

Amphiesmenoptera

• Trichoptera (caddisflies)
• Lepidoptera (butterflies, moths, skippers)

Insects can be divided into two groups, historically treated as subclasses: Apterygota (wingless) and Pterygota (winged). The Endopterygota, also known as Holometabola, are Insects of the subclass Pterygota which go through distinctive Larval Pupal Glosselytrodea is an Extinct order of insects Miomoptera is an extinct order of insects It is considered to be a common ancestor of all Holometabolous insects but because there is no known smooth transition Hymenoptera is one of the larger orders of Insects comprising the sawflies, Wasps Bees and Ants The name refers to Beetles are the group of Insects with the largest number of known Species. The Strepsiptera (known in older literature as twisted-winged parasites) are an order of Insects with nine families making up about 600 species The Neuropterida are a Clade of Holometabolous Insects Well-known members are the Lacewings Antlions and Dobsonflies Snakeflies are a group of Insects in the order Raphidioptera, consisting of about 150 Species. Megaloptera is an order of Insects It contains the alderflies, Dobsonflies and fishflies, and there are about 300 known For the obsolete concept of the Neuroptera including Alderflies, Dobsonflies, Fishflies and Snakeflies, see Neuropterida. Mecoptera (from the Greek: meco- = "long" -ptera = "wings" are an order of Insects with about 550 species in nine families Flea is the Common name for any of the small wingless Insects of the order Siphonaptera (some authorities use the name Aphaniptera Flies in the Diptera family Syrphidae are commonly known as hoverflies, flower flies, or Syrphid flies. Grape hyacinths are a group of plants in the Genus Muscari of Plants native to Eurasia that produce spikes of blue Flowers resembling True flies are Insects of the Order Diptera ( Greek: di = two and pteron = wing possessing a single pair of Protodiptera is an extinct order of insects Amphiesmenoptera is an Insect Superorder, established by Willi Hennig in his revision of insect taxonomy for two sister orders Lepidoptera Caddisflies, sedge-flies or rail flies (Order Trichoptera, from Greek trich, "hair" and ptera, "wings" Lepidoptera is an order of Insect that includes Moths and butterflies. The Apterygota consists of two primitively wingless orders - Archaeognatha (bristletails) and Thysanura (silverfish). Archaeognatha makes up the Monocondylia (based on mandibular morphology) while Thysanura and Pterygota are grouped together as Dicondylia. It is possible that the Thysanura itself is not monophyletic, with the family Lepidotrichidae a sister group to the Dicondylia (Pterygota + the remaining Thysanura). A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor Lepidotrichidae is a family of basal Insects belonging to the order Thysanura. Cladistics is the hierarchical classification of Species based on evolutionary ancestry

Paleoptera and Neoptera are the winged orders of insects, separated by the presence of sclerites and musculature that allow for folding of the wings flat over the abdomen in the latter group. Neoptera can further be divided into hemimetabolous (Polyneoptera & Paraneoptera) and Holometabolous groups. It has proven particularly difficult to elucidate interordinal relationships within Polyneoptera. Phasmatodea and Embiidina have been suggested to form Eukinolabia. ^[27] Mantodea, Blattodea & Isoptera are thought to form a monophyletic group termed Dictyoptera. Dictyoptera includes three groups of polyneopterous insects - cockroaches ( Blattaria) termites ( Isoptera) and mantids ( Mantodea) ^[28] Paraneoptera has turned out to be more closely related to Endopterygota than to the rest of the Exopterygota. The recent molecular finding that the traditional louse orders Mallophaga and Anoplura are derived from within Psocoptera has led to the new taxon Psocodea. Chewing lice ( Mallophaga) have nearly 3000 species and represent the larger of the two traditional suborders of Lice (cf Sucking lice ( Anoplura) have around 500 Species and represent the smaller of the two traditional suborders of Lice. Psocoptera are an order of Insects that are commonly known as booklice, barklice or barkflies. ^[29]

It is quite likely that Exopterygota is paraphyletic in regards to Endopterygota. In Phylogenetics, a group of organisms is said to be paraphyletic if the group contains its most recent common ancestor but does not contain all Contentious matters include Strepsiptera and Diptera grouped together as Halteria based on a reduction of one of the wing pairs - a position not well-supported in the entomological community. ^[30] The Neuropterida are often "lumped" or "split" on the whims of the taxonomist. Fleas are now thought to be closely related to boreid mecopterans. ^[31] Many questions remain to be answered when it comes to basal relationships amongst endopterygote orders, particularly Hymenoptera.

Relationship to humans

Aedes aegypti, a parasite, and vector of dengue fever and yellow fever

Many insects are considered pests by humans. The yellow fever mosquito, Stegomyia aegypti (= Aedes aegypti, = Aedes (Stegomyia aegypti) is a Mosquito Yellow fever (also called yellow jack, black vomit or sometimes American Plague) is an acute viral disease Insects commonly regarded as pests include those that are parasitic (mosquitoes, lice, bed bugs), transmit diseases (mosquitoes, flies), damage structures (termites), or destroy agricultural goods (locusts, weevils). Mosquitoes are insects in the family Culicidae. They have a pair of scaled wings a pair of Halteres, a slender body and long legs Lice (singular louse) ( order Phthiraptera) are an order of over 3000 Species of wingless Insects three of which are classified A bedbug (or bed bug) is a small nocturnal Insect of the family Cimicidae that lives by Hematophagy, or by feeding on the Blood Mosquitoes are insects in the family Culicidae. They have a pair of scaled wings a pair of Halteres, a slender body and long legs True flies are Insects of the Order Diptera ( Greek: di = two and pteron = wing possessing a single pair of The termites are a group of Social Insects usually classified at the taxonomic rank of order Isoptera (but see also taxonomy Locust is the Swarming phase of short-horned Grasshoppers of the family Acrididae. A weevil is any Beetle from the Curculionoidea Superfamily. They are usually small less than 6  mm (¼  Inch) and herbivorous Many entomologists are involved in various forms of pest control, often using insecticides, but more and more relying on methods of biocontrol. Entomology (from Greek grc ἔντομος entomos, "that which is cut in pieces or engraved/segmented" hence "insect" and grc -λογία A pest is an organism which has characteristics that are regarded by Humans as injurious or unwanted An insecticide is a Pesticide used against Insects in all developmental forms Biological control of pests in Agriculture is a method of controlling pests (including Insects Mites Weeds and plant diseases

Although pest insects attract the most attention, many insects are beneficial to the environment and to humans. See also Natural environment The '''biophysical''' environment is the symbiosis between the physical environment and the Biological Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus Some pollinate flowering plants (for example wasps, bees, butterflies, ants). Pollination in angiosperms and Gymnosperms is the process that transfers pollen grains, which contain the male Gametes (sperm to where the female The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group A wasp is any Insect of the order Hymenoptera and suborder Apocrita that is neither a Bee nor Ant. Bees are flying Insects closely related to Wasps and Ants Bees are a Monophyletic lineage within the superfamily Apoidea A butterfly is an Insect of the order Lepidoptera. Like all Lepidoptera butterflies are notable for their unusual life cycle with a Ants are social Insects of the family Formicidae and along with the related families of Wasps and Bees belong to the order Pollination is a trade between plants that need to reproduce, and pollinators that receive rewards of nectar and pollen. Nectar is a Sugar -rich liquid produced by plants It is produced either by the Flowers in which it attracts pollinating animals or by extrafloral Pollen is a fine to coarse powder consisting of microgametophytes ( pollen grains) which produce the male Gametes (sperm cells of A serious environmental problem today is the decline of populations of pollinator insects, and a number of species of insects are now cultured primarily for pollination management in order to have sufficient pollinators in the field, orchard or greenhouse at bloom time. The term Pollinator decline refers to the reduction in abundance of Pollinators in many Ecosystems worldwide during the end of the twentieth century Pollination Management is the label for horticultural practices that accomplish or enhance Pollination of a crop to improve yield or quality by understanding of the particular An orchard is an intentional planting of Trees or Shrubs maintained for Food production. A greenhouse (also called a glasshouse or hothouse) is a building where plants are cultivated

Insects also produce useful substances such as honey, wax, lacquer and silk. Honey is a sweet and Viscous fluid produced by Honey bees (and some other species and derived from the nectar of Flowers According to the Wax has traditionally referred to a substance that is secreted by Bees ( Beeswax) and used by them in constructing their In a general sense lacquer is a clear or coloured Varnish, that dries by solvent evaporation and often a curing process as well that produces a hard durable finish in any Silk is a natural Protein Fiber, some forms of which can be woven into Textiles The best-known type of silk is obtained from cocoons Honey bees have been cultured by humans for thousands of years for honey, although contracting for crop pollination is becoming more significant for beekeepers. This article refers collectively to all true honey bees for the "common" domesticated honey bee see European honey bee Honey bees A beekeeper is a person who keeps Honey bees for the purposes of securing commodities such as Honey, Beeswax, Pollen; pollinating The silkworm has greatly affected human history, as silk-driven trade established relationships between China and the rest of the world. The Silk Road, or Silk Routes, are an extensive interconnected network of Trade routes across the Asian continent connecting East South and Western Asia with the Fly larvae (maggots) were formerly used to treat wounds to prevent or stop gangrene, as they would only consume dead flesh. True flies are Insects of the Order Diptera ( Greek: di = two and pteron = wing possessing a single pair of Maggot is the common name of the Larval phase of development in insects of the order Diptera (flies Maggot therapy (also known as maggot debridement therapy (MDT larval therapy larva therapy larvae therapy biodebridement or biosurgery is a type of Biotherapy involving Please do not add warnings to this page about the pictures Wikipedia is not censored for taste and has a guideline preventing such warnings - WikipediaNo disclaimers in articles This treatment is finding modern usage in some hospitals. Adult insects such as crickets, and insect larvae of various kinds are also commonly used as fishing bait.

Chorthippus biguttulus, a grasshopper

In some parts of the world, insects are used for human food ("Entomophagy"), while being a taboo in other places. Entomophagy (from Greek ἔντομος éntomos, "insect(ed" and φᾰγεῖν phăgein, "to eat" which together A taboo is a strong Social prohibition (or ban) against words objects actions or discussions that are considered undesirable or offensive by a group culture There are proponents of developing this use to provide a major source of protein in human nutrition. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Nutrition (also called nourishment or aliment) is the provision to cells and Organisms of the materials necessary (in the form of food to support Since it is impossible to entirely eliminate pest insects from the human food chain, insects already are present in many foods, especially grains. Most people do not realize that food safety laws in many countries do not prohibit insect parts in food, but rather limit the quantity. Food safety is a scientific discipline describing handling preparation, and storage of Food in ways that prevent Foodborne illness. According to cultural materialist anthropologist Marvin Harris, the eating of insects is taboo in cultures that have protein sources that require less work, like farm birds or cattle. Marvin Harris ( August 18, 1927 &ndash October 25, 2001) was an American Anthropologist.

Many insects, especially beetles, are scavengers, feeding on dead animals and fallen trees, recycling the biological materials into forms found useful by other organisms, and insects are responsible for much of the process by which topsoil is created. Beetles are the group of Insects with the largest number of known Species. Scavenging, or necrophagy, is a Carnivorous Feeding behaviour in which a predator consumes Corpses or Carrion that were killed Recycling involves processing used materials into new products in order to prevent the waste of potentially useful materials reduce the consumption of fresh raw materials reduce Topsoil is the upper outermost layer of soil usually the top 2 to 8 inches The ancient Egyptian religion adored dung beetles and represented them as beetle-shaped amulets, or scarabs. Ancient Egyptian religion encompasses the various religious beliefs and rituals practiced in Ancient Egypt from the predynastic period until the adoption of Christianity Dung beetles are beetles which feed partly or exclusively on Feces. An amulet ( the Elder|Pliny]] meaning "an object that protects a person from trouble" a close cousin of the talisman (from Arabic

The most useful of all insects are insectivores, those that feed on other insects. An insectivore is a type of carnivore with a diet that consists chiefly of Insects and similar small creatures Many insects can potentially reproduce so quickly that if all of their offspring were to survive, they could literally bury the earth in a single season. However, for any given insect one can name, whether it is considered a pest or not, there will be one to hundreds of species of insects that are either parasitoids or predators upon it, and play a significant role in controlling it. A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host Organism which it ultimately kills This role in ecology is usually assumed to be primarily one of birds, but insects, though less glamorous, are much more significant. Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs.

Human attempts to control pests by insecticides can backfire, because important but unrecognised insects already helping to control pest populations are also killed by the poison, leading eventually to population explosions of the pest species.

Quotations

• "Something in the insect seems to be alien to the habits, morals, and psychology of this world, as if it had come from some other planet: more monstrous, more energetic, more insensate, more atrocious, more infernal than our own. "

—Maurice Maeterlinck (1862–1949)

• When asked what can be learned about the Creator by examining His work, J.B.S. Haldane said "an inordinate fondness for beetles. Maurice Polydore Marie Bernard Count Maeterlinck ( August 29, 1862 - May 6, 1949) was a Belgian Poet, Playwright, John Burdon Sanderson Haldane FRS ( 5 November 1892 &ndash 1 December 1964) known as Jack (but who used 'J "

• "To understand the success of insects is to appreciate our own shortcomings" —Thomas Eisner

See also

• Animal
• Flying and gliding animals
• Entomology
• Invertebrate
• Prehistoric insect
• Insect flight
• Insect ecology
• Category:Insect-borne diseases

References

Further reading

• Davidson, E. (ed. ) 1981. Pathogenesis of Invertebrate Micorobial Diseases. Allanheld, Osmun & Co. Publishers, Inc. , Totowa, New Jersey, USA. 562 pages.
• Davidson, E. 2006. Big Fleas Have Little Fleas: How Discoveries of Invertebrate Diseases Are Advancing Modern Science University of Arizona Press, Tucson, 208 pages, ISBN 0-8165-2544-7
• Davidson, RH and William F. Lyon. 1979 Insect Pests of Farm, Garden, and Orchard. John Wiley & Sons. , New York. 596 pages, ISBN 0-471-86314-9.
• Grimaldi, D. and Engel, M.S. (2005). David A Grimaldi (born September 22, 1957) is an entomologist and Curator of Invertebrate Zoology at the American Museum of Natural History in Michael S Engel (born 24 September 1971 in Creve Coeur Missouri) is a Paleontologist and Entomologist. Evolution of the Insects. Cambridge University Press. Cambridge University Press (known colloquially as CUP is a Publisher given a Royal Charter by Henry VIII in 1534 ISBN 0-521-82149-5.  
• Reimer, N. J. , J. W. Beardsley, and G. C. Jahn 1990. Pest ants in the Hawaiian Islands. In R. Vander Meer, K. Jaffe, and A. Cedena [eds. ], "Applied Myrmecology: a world perspective. " Westview Press, Oxford, 40-50.
• Triplehorn, Charles A. and Norman F. Johnson (2005-05-19). Borror and DeLong's Introduction to the Study of Insects, 7th edition, Thomas Brooks/Cole. ISBN 0-03-096835-6. — a classic textbook in North America
• Grimaldi, D. and Engel, M.S. (2005). David A Grimaldi (born September 22, 1957) is an entomologist and Curator of Invertebrate Zoology at the American Museum of Natural History in Michael S Engel (born 24 September 1971 in Creve Coeur Missouri) is a Paleontologist and Entomologist. Evolution of the Insects. Cambridge University Press. Cambridge University Press (known colloquially as CUP is a Publisher given a Royal Charter by Henry VIII in 1534 ISBN 0-521-82149-5.   — an up to date review of the evolutionary history of the insects
• Rasnitsyn, A.P. and Quicke, D. Alexandr (Alex P Rasnitsyn (born 24 September 1936 in Moscow) is one of the world's leading experts in Palaeoentomology. L. J. (2002). History of Insects. Kluwer Academic Publishers. Springer Science+Business Media or Springer (ˈʃpʁɪŋɐ is a worldwide Publishing company based in Germany, which publishes textbooks academic ISBN 1-4020-0026-X.   — detail coverage of various aspects of the evolutionary history of the insects
• Biewener, Andrew A. (2003). Animal Locomotion. Oxford University Press. ISBN 0-19-850022-X.  
• Merritt, RW, KW Cummins, and MB Berg (2007). An Introduction To The Aquatic Insects Of North America. Kendall Hunt Publishing Company. ISBN 0-7575-4128-3.  

External links

• Tree of Life Project – Insecta, Insecta Movies
• Insect Morphology Overview of insect external and internal anatomy
• Let's Talk About Insects For students ages 9-11 years, learn how insects grow and develop (metamorphosis), and learn the importance of insects in our environment. (Also in Spanish)
• Meganeura Insect evolution and fossil record.
• IPS International Palaeoentological Society.
• UF Book of Insect Records Insect records
• Insect Walking Research into Insect Locomotion at the University of Illinois
• Press Release 2002 on research into polypodal locomotion
• Insectclopedia Insect research portal
• Insects as Food Insects as a food resource.
• Insects and human culture
• Information on keeping, breeding and rearing Insects and invertebrates.
• Bug Bytes Reference library of digitized insect sounds.
• INSECTS .org Insect appreciation.
• The Unexpected Apocalypse. Entomologist May Berenbaum about a world without insects.
• Pentagon plans cyber-insect army
• Introduction to the Natural History and Classification of Insects in a Series of Familiar Letters with Engravings, Priscilla Wakefield, 1816 A free to read book
• Earthlife Web - Insect Morphology and Anatomy
• Featured Creatures Hundreds of species and groups
• WoodyBug S. E. U. S. woody ornamental pests and beneficials
• Public Health Pest Control - EPA national manual on public health arthropods
• Video: Life Cycle of a Honeybee

Image resources

• BugGuide Photographs, life history and identification of North American arthropods, especially insects
• LiveScience: Insects Insect information and user-submitted insect pictures
• ESALQ Entomological Museum 6000 insect pictures. Brazilian collection (ESALQ/USP).
• North American Insects 4,000 large format insect pictures. Creative Commons licensed
• Pictures of Florida insects
• InsectImages.org 24,000 high resolution insect photographs. Free for non-profit educational uses.