Evolution has produced enormous variety in insects. Pictured are some possible shapes of antennae.
A pie chart of described eukaryote species, showing just over half of these to be insects
Insects with population trends documented by the International Union for Conservation of Nature, for orders Collembola, Hymenoptera, Lepidoptera, Odonata, and Orthoptera. Of 203 insect species that had such documented population trends in 2013, 33% were in decline.
Stylized diagram of insect digestive tract showing malpighian tubule, from an insect of the order Orthoptera
Bumblebee defecating. Note the contraction of the abdomen to provide internal pressure
The tube-like heart (green) of the mosquito Anopheles gambiae extends horizontally across the body, interlinked with the diamond-shaped wing muscles (also green) and surrounded by pericardial cells (red). Blue depicts cell nuclei.
The different forms of the male (top) and female (bottom) tussock moth Orgyia recens is an example of sexual dimorphism in insects.
Gulf fritillary life cycle, an example of holometabolism.
Most insects have compound eyes and two antennae.
A cathedral mound created by termites (Isoptera).
White-lined sphinx moth feeding in flight
The backswimmer Notonecta glauca underwater, showing its paddle-like hindleg adaptation
Perhaps one of the most well-known examples of mimicry, the viceroy butterfly (top) appears very similar to the monarch butterfly (bottom).
European honey bee carrying pollen in a pollen basket back to the hive
Aedes aegypti, a parasite, is the vector of dengue fever and yellow fever
Because they help flowering plants to cross-pollinate, some insects are critical to agriculture. This European honey bee is gathering nectar while pollen collects on its body.
A robberfly with its prey, a hoverfly. Insectivorous relationships such as these help control insect populations.
The common fruit fly Drosophila melanogaster is one of the most widely used organisms in biological research.

Insects (from Latin insectum) are pancrustacean hexapod invertebrates of the class Insecta.

- Insect
Evolution has produced enormous variety in insects. Pictured are some possible shapes of antennae.

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Parts of an adult butterfly
A – head, B – thorax, C – abdomen,
1 – prothoracic shield,
2 – spiracle,
3 – true legs,
4 – midabdominal prolegs,
5 – anal proleg,
6 – anal plate,
7 – tentacle,
a – eye,
b – stemmata (ocelli),
c – antenna,
d – mandible,
e – labrum, 
f – frontal triangle.
Face of a caterpillar with the mouthparts showing
Caterpillar prolegs on Papilio machaon
Wing scales form the color and pattern on wings. The scales shown here are lamellar. The pedicel can be seen attached to a few loose scales.
Internal morphology of adult male in the family Nymphalidae, showing most of the major organ systems, with characteristic reduced forelegs of that family: The corpora include the corpus allatum and the corpus cardiaca.
Sexually dimorphic bagworm moths (Thyridopteryx ephemeraeformis) mating: The female is flightless.
The Heliconius butterflies from the tropics of the Western Hemisphere are the classical model for Müllerian mimicry.
Mating pair of Laothoe populi (poplar hawk-moth) showing two different color variants
The four stages of the life cycle of an anise swallowtail
Larval form typically lives and feeds on plants
Long exposure image of flying moths, attracted to the floodlights
Monarch butterflies, seen in a cluster in Santa Cruz, California, where the western population migrates for the winter
Group of Melitaea athalia near Warka, Poland
Papilio machaon caterpillar showing the osmeterium, which emits unpleasant smells to ward off predators
A day-flying hummingbird hawk-moth drinking nectar from a species of Dianthus
Tobacco hornworm caterpillar (Manduca sexta) parasitized by Braconidae wasp larvae
Parasitoid larva exits from the fox moth caterpillar
Lepidoptera collection in Cherni Osam Natural Sciences Museum, Troyan, Bulgaria
1887 engraving of Prodryas persephone, a fossil lepidopteran from the Eocene.
Phylogenetic hypothesis of major lepidopteran lineages superimposed on the geologic time scale. Radiation of angiosperms spans from their earliest forms to domination of vegetation.
Death's-head hawkmoth (Acherontia lachesis), an old bleached specimen still showing the classical skull pattern on the thorax
Beondegi, silkworm pupae steamed or boiled and seasoned for taste, for sale by a street vendor in South Korea

Lepidoptera is an order of insects that includes butterflies and moths (both are called lepidopterans).


Arthropods (, (gen.

Arthropods (, (gen.

Structure of a biramous appendage.
Alignment of anterior body segments and appendages across various arthropod taxa, based on the observations until mid 2010s. Head regions in black.
Illustration of an idealized arthropod exoskeleton.
Cicada climbing out of its exoskeleton while attached to tree
Arthropod eyes
Head of a wasp with three ocelli (center), and compound eyes at the left and right
Compsobuthus werneri female with young (white)
The nauplius larva of a penaeid shrimp
Marrella, one of the puzzling arthropods from the Burgess Shale
The velvet worm (Onychophora) is closely related to arthropods
Insects and scorpions on sale in a food stall in Bangkok, Thailand

One arthropod sub-group, insects, is the most species-rich member of all ecological guilds in land and freshwater environments.


Coleoptera at the Staatliches Museum für Naturkunde Karlsruhe, Germany
Fossil and life restoration of Moravocoleus permianus (Tshekardocoleidae) from the Early Permian of the Czech Republic, representative of the morphology of early beetles
Beetle genera were mainly saprophages (detritivores) in the Permian and Triassic. During the Jurassic, herbivorous and then carnivorous genera became more common. In the Cenozoic, genera at all three trophic levels became far more numerous.
Fossil buprestid beetle from the Eocene (50 mya) Messel pit, which retains its structural color
Beetle body structure, using cockchafer.
A: head, B: thorax, C: abdomen.
1: antenna, 2: compound eye, 3: femur, 4: elytron (wing cover), 5: tibia, 6: tarsus, 7: claws, 8: mouthparts, 9: prothorax, 10: mesothorax, 11: metathorax, 12: abdominal sternites, 13: pygidium.
Front view of the head of Lamia textor
Polyphylla fullo has distinctive fan-like antennae, one of several distinct forms for the appendages among beetles.
Acilius sulcatus, a diving beetle with hind legs adapted as swimming limbs
Checkered beetle Trichodes alvearius taking off, showing the hard elytra (forewings adapted as wing-cases) held stiffly away from the flight wings
A beetle's body systems
Punctate flower chafers (Neorrhina punctata, Scarabaeidae) mating
The life cycle of the stag beetle includes three instars.
Scarabaeiform larva of Hercules beetle
The ivory-marked beetle, Eburia quadrigeminata, may live up to 40 years inside the hardwoods on which the larva feeds.
Photinus pyralis, firefly, in flight
A dung beetle rolling dung
Hycleus sp. (Meloidae) feeding on the petals of Ipomoea carnea
A camouflaged longhorn beetle, Ecyrus dasycerus
Clytus arietis (Cerambycidae), a Batesian mimic of wasps
Blister beetles such as Hycleus have brilliant aposematic coloration, warning of their toxicity.
An Israeli Copper Flower-Chafer (Protaetia cuprea ignicollis) on a crown daisy (Glebionis coronaria)
1: Adult ambrosia beetle burrows into wood and lays eggs, carrying fungal spores in its mycangia. 
2: Larva feeds on fungus, which digests wood, removing toxins, to mutual benefit. 
3: Larva pupates.
Tenebrionid beetle in the Thar Desert
The fogstand beetle of the Namib Desert, Stenocara gracilipes, is able to survive by collecting water from fog on its back.
A scarab in the Valley of the Kings
Cotton boll weevil
Larvae of the Colorado potato beetle, Leptinotarsa decemlineata, a serious crop pest
Coccinella septempunctata, a predatory beetle beneficial to agriculture
Mealworms in a bowl for human consumption
Zopheridae in jewellery at the Texas A&M University Insect Collection
"Remarkable Beetles Found at Simunjon, Borneo". A few of the 2,000 species of beetle collected by Alfred Russel Wallace in Borneo
Titan beetle, Titanus giganteus, a tropical longhorn, is one of the largest and heaviest insects in the world.
Scydosella musawasensis, the smallest known beetle: scale bar (right) is 50 μm.
Hercules beetle, Dynastes hercules ecuatorianus, the longest of all beetles
iridescent Protaetia cuprea feeding on thistle
iridescent Protaetia cuprea feeding on thistle

Beetles are insects that form the order Coleoptera, in the superorder Endopterygota.


Fossil planthopper (Fulgoromorpha) from the Early Cretaceous Crato Formation of Brazil, c. 116 mya
Hemipteran mouthparts are distinctive, with mandibles and maxillae modified to form a piercing "stylet" sheathed within a modified labium.
An ant-mimicking predatory bug Myrmecoris gracilis
Aphid giving birth to live female young
Pondskaters are adapted to use surface tension to keep above a freshwater surface.
Adult and nymph Microvelia water bugs using Marangoni propulsion
Leaf galls formed by plant lice (Psyllidae), Chamaesyce celastroides var. stokesii
A twig wilting bug (Coreidae) piercing and sucking sap from a Zinnia
Leafhoppers protected by meat ants
Masked hunter nymph has camouflaged itself with sand grains.
Firebugs, Pyrrhocoris apterus, protect themselves from predators with bright aposematic warning coloration, and by aggregating in a group.
Colony of cottony cushion scale, a pest of citrus fruits
Cochineal scale insects being collected from a prickly pear in Central America. Illustration by José Antonio de Alzate y Ramírez, 1777
Bed bug nymph, Cimex lectularius, engorged with human blood
Deep-fried cicadas, Cryptotympana atrata, in Chinese Shandong cuisine

Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, bed bugs, and shield bugs.


Ants fossilised in Baltic amber
Diagram of a worker ant (Neoponera verenae)
Bull ant showing the powerful mandibles and the relatively large compound eyes that provide excellent vision
Ant head
Seven leafcutter ant workers of various castes (left) and two queens (right)
Meat eater ant nest during swarming
Alate male ant, Prenolepis imparis
Honey ants (Prenolepis imparis) mating
Fertilised meat-eater ant queen beginning to dig a new colony
Two Camponotus sericeus workers communicating through touch and pheromones
A Plectroctena sp. attacks another of its kind to protect its territory.
A weaver ant in fighting position, mandibles wide open
Ant mound holes prevent water from entering the nest during rain.
Two Weaver ants walking in tandem.
Leaf nest of weaver ants, Pamalican, Philippines
Myrmecocystus, honeypot ants, store food to prevent colony famine.
An ant trail
Meat-eater ants feeding on a cicada: social ants cooperate and collectively gather food
A worker Harpegnathos saltator (a jumping ant) engaged in battle with a rival colony's queen (on top)
The spider Myrmarachne plataleoides (female shown) mimics weaver ants to avoid predators.
An ant collects honeydew from an aphid
Ants may obtain nectar from flowers such as the dandelion, but are only rarely known to pollinate flowers.
A meat ant tending a common leafhopper nymph
Spiders (Like this Menemerus jumping spider) sometimes feed on ants
Weaver ants are used as a biological control for citrus cultivation in southern China.
Roasted ants in Colombia
Ant larvae for sale in Isaan, Thailand
The tiny pharaoh ant is a major pest in hospitals and office blocks; it can make nests between sheets of paper.
Camponotus nearcticus workers travelling between two formicaria through connector tubing
Aesop's ants: illustration by Milo Winter, 1888–1956
An ant pictured in the coat of arms of Multia

Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera.

Solitary predator: a polar bear feeds on a bearded seal it has killed.


Animal, actually ->

Animal, actually ->

Solitary predator: a polar bear feeds on a bearded seal it has killed.
Social predators: meat ants cooperate to feed on a cicada far larger than themselves.
Spider wasps paralyse and eventually kill their hosts, but are considered parasitoids, not predators.
Relation of predation to other feeding strategies
Paramecium, a predatory ciliate, feeding on bacteria
A basic foraging cycle for a predator, with some variations indicated
The black-browed albatross regularly flies hundreds of kilometres across the nearly empty ocean to find patches of food.
Seven-spot ladybirds select plants of good quality for their aphid prey.
The chameleon attacks prey by shooting out its tongue.
Wolves, social predators, cooperate to hunt and kill bison.
An electric ray (Torpediniformes) showing location of electric organ and electrocytes stacked within it
Bats use echolocation to hunt moths at night.
Eastern coral snake, itself a predator, is venomous enough to kill predators that attack it, so when they avoid it, this behaviour must be inherited, not learnt.
Riparian willow recovery at Blacktail Creek, Yellowstone National Park, after reintroduction of wolves, the local keystone species and apex predator. Left, in 2002; right, in 2015
Numbers of snowshoe hare (Lepus americanus) (yellow background) and Canada lynx (black line, foreground) furs sold to the Hudson's Bay Company from 1845 to 1935
Predator-prey population cycles in a Lotka-Volterra model
San hunter, Botswana
The Capitoline Wolf suckling Romulus and Remus, the mythical founders of Rome
Skull of brown bear has large pointed canines for killing prey, and self-sharpening carnassial teeth at rear for cutting flesh with a scissor-like action
Large compound eyes, sensitive antennae, and powerful jaws (mandibles) of jack jumper ant
Crab spider, an ambush predator with forward-facing eyes, catching another predator, a field digger wasp
Red-tailed hawk uses sharp hooked claws and beak to kill and tear up its prey
Specialist: a great blue heron with a speared fish
Indian python unhinges its jaw to swallow large prey like this chital
The Cambrian substrate revolution saw life on the sea floor change from minimal burrowing (left) to a diverse burrowing fauna (right), probably to avoid new Cambrian predators.
Mouth of the anomalocaridid Laggania cambria, a Cambrian invertebrate, probably an apex predator
Dunkleosteus, a Devonian placoderm, perhaps the world's first vertebrate superpredator, reconstruction
Meganeura monyi, a predatory Carboniferous insect related to dragonflies, could fly to escape terrestrial predators. Its large size, with a wingspan of {{convert|65|cm|in|-1|abbr=on}}, may reflect the lack of vertebrate aerial predators at that time.
Tyrannosaurus, a large theropod dinosaur of the Cretaceous, reconstruction

Insects developed the ability to fly in the Early Carboniferous or Late Devonian, enabling them among other things to escape from predators.

Pupa of the rose chafer beetle, Cetonia aurata


Pupa of the rose chafer beetle, Cetonia aurata
Tumbler (pupa) of a mosquito. Unlike most pupae, tumblers can swim around actively.
Adult Hercus fontinalis emerging from cocoon
Mating in pierid Catopsilia pyranthe of male with newly emerged female.
Common crow butterfly (Euploea core) chrysalis illustrating the Ancient Greek origin of the term: χρυσός (chrysós) for gold
The tough brown cocoon of an emperor gum moth
Puparium of Eupeodes americanus
Fruit fly (Drosophila melanogaster) pupa
An emperor gum moth caterpillar spinning its cocoon
Luna moth cocoon and pupa
Assortment of Luna moth cocoons
Luna moth emerging from pupa within silk cocoon
Luna moth pupa removed from cocoon
Chrysalis of Gulf fritillary
Pupation of Aglais io
Monarch butterfly chrysalis
Specimen of an eclosing Dryas iulia butterfly
Pupae of Japanagromyza inferna, a gall fly, in gall of Centrosema virginianum
Pupa of cabbage looper
Pupa of Baron Butterfly Euthalia aconthea
thumb|Papilio_polytes_common_Mormon_pupa on curry leaves.

A pupa (pupa, "doll"; plural: pupae) is the life stage of some insects undergoing transformation between immature and mature stages.


Long-tongued bees and long-tubed flowers coevolved, like this Amegilla cingulata (Apidae) on Acanthus ilicifolius.
The lapping mouthparts of a honey bee, showing labium and maxillae
Head-on view of a male carpenter bee, showing antennae, three ocelli, compound eyes, and mouthparts
Willing to die for their sisters: worker honey bees killed defending their hive against yellowjackets, along with a dead yellowjacket. Such altruistic behaviour may be favoured by the haplodiploid sex determination system of bees.
A Western honey bee swarm
Western honey bee nest in the trunk of a spruce
A bumblebee carrying pollen in its pollen baskets (corbiculae)
A leafcutting bee, Megachile rotundata, cutting circles from acacia leaves
A solitary bee, Anthidium florentinum (family Megachilidae), visiting Lantana
The mason bee Osmia cornifrons nests in a hole in dead wood. Bee "hotels" are often sold for this purpose.
Honeybee in flight carrying pollen in pollen basket
Karl von Frisch (1953) discovered that honey bee workers can navigate, indicating the range and direction to food to other workers with a waggle dance.
The bee-fly Bombylius major, a Batesian mimic of bees, taking nectar and pollinating a flower.
Bee orchid lures male bees to attempt to mate with the flower's lip, which resembles a bee perched on a pink flower.
Bombus vestalis, a brood parasite of the bumblebee Bombus terrestris
The bee-eater, Merops apiaster, specialises in feeding on bees; here a male catches a nuptial gift for his mate.
The beewolf Philanthus triangulum paralysing a bee with its sting
Gold plaques embossed with winged bee goddesses. Camiros, Rhodes. 7th century B.C.
Beatrix Potter's illustration of Babbity Bumble in The Tale of Mrs Tittlemouse, 1910
A commercial beekeeper at work
Western honey bee on a honeycomb
Squash bees (Apidae) are important pollinators of squashes and cucumbers.
Bee covered in pollen
Bee larvae as food in the Javanese dish botok tawon
Fried whole bees served in a Ukrainian restaurant
Nest of common carder bumblebee, wax canopy removed to show winged workers and pupae in irregularly placed wax cells
Carpenter bee nests in a cedar wood beam (sawn open)
Honeybees on brood comb with eggs and larvae in cells

Bees are winged insects closely related to wasps and ants, known for their role in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey.


Possibly the original butter-fly. A male brimstone (Gonepteryx rhamni) in flight
Prodryas persephone, a Late Eocene butterfly from the Florissant Fossil Beds, 1887 engraving
Lithopsyche antiqua, an Early Oligocene butterfly from the Bembridge Marls, Isle of Wight, 1889 engraving
The wings of butterflies, here Aglais io, are covered with coloured scales.
Butterfly antennal shapes, mainly clubbed, unlike those of moths. Drawn by C. T. Bingham, 1905
Unlike butterflies, most moths (like Laothoe populi) fly by night and hide by day.
Monarch migration route
Overwintering monarchs cluster on oyamel trees near Angangueo, Mexico.
Life cycle of the monarch butterfly
Mating pair of spotted fritillaries on greater pignut
The male small skipper (Thymelicus sylvestris) has pheromone-releasing "sex brands" (dark line) on the upperside of its forewings.
Eggs of black-veined white (Aporia crataegi) on apple leaf
A butterfly laying eggs underneath the leaf
Aposematic caterpillar of Papilio machaon, in threat pose
Mutualism: ant tending a lycaenid caterpillar, Catapaecilma major
Cryptic countershaded caterpillar of a hawkmoth, Ceratomia amyntor
Chrysalis of gulf fritillary
An adult Parthenos sylvia butterfly
An Australian painted lady feeding on a flowering shrub
Heteronympha merope taking off
Braconid parasitoidal wasp (Apanteles species) cocoons attached to lime butterfly (Papilio demoleus) caterpillar
Heliconius warns off predators with Müllerian mimicry.
Giant swallowtail caterpillar everting its osmeterium in defence; it is also mimetic, resembling a bird dropping.
Eyespots of speckled wood (Pararge aegeria) distract predators from attacking the head. This insect can still fly with a damaged left hindwing.
Ancient Egyptian relief sculpture, 26th dynasty, Thebes. c. 664–525 BC
Butterfly and Chinese wisteria, by Xü Xi. Early Song Dynasty, c. 970
A butterfly in the coat of arms of Perho
Alice meets the caterpillar. Illustration by Sir John Tenniel in Lewis Carroll's Alice in Wonderland, c. 1865
Der Schmetterlingsjäger (The butterfly hunter) painting by Carl Spitzweg, 1840
A serving tray decorated with butterfly wings
Nō robe Japan 1700s. Silk embroidered with silk thread and stenciled with gold foil

Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths.


Forewing of the early Middle Triassic (early Anisian) aphid Vosegus triassicus
An aphid fossilised in Baltic amber (Eocene)
Front view of wheat aphid, Schizaphis graminum, showing the piercing-sucking mouthparts
Soybean aphid alternates between hosts and between asexual and sexual reproduction.
Aphid giving birth to live young: populations are often entirely female.
The life stages of the green apple aphid (Aphis pomi). Drawing by Robert Evans Snodgrass, 1930
An ant guards its aphids
Ants tending aphids
Ant extracting honeydew from an aphid
Aphid secreting defensive fluid from the cornicles
Aphids on plant host
Aphid with honeydew, from the anus, not the cornicles
Parasitoid braconid wasp ovipositing in black bean aphid
Green peach aphid, Myzus persicae, killed by the fungus Pandora neoaphidis (Entomophthorales)

Aphids are small sap-sucking insects and members of the superfamily Aphidoidea.