Hemiptera (; ) is an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

s, commonly called true bugs, comprising over 80,000

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

within groups such as the cicadas, aphids, planthoppers,

leafhopper A leafhopper is the common name for any species from the family Cicadellidae. These minute insects, colloquially known as hoppers, are plant feeders that suck plant sap from grass, shrubs, or trees. Their hind legs are modified for jumping, and ...

assassin bugs The Reduviidae are a large cosmopolitan family of the order Hemiptera (true bugs). Among the Hemiptera and together with the Nabidae almost all species are terrestrial ambush predators: most other predatory Hemiptera are aquatic. The main examp ...

bed bug Bed bugs are insects from the genus ''Cimex'' that feed on blood, usually at night. Their bites can result in a number of health impacts including skin rashes, psychological effects, and allergic symptoms. Bed bug bites may lead to skin changes ...

s, and shield bugs. They range in size from to around , and share a common arrangement of piercing-sucking

mouthparts Mouthparts may refer to: * The parts of a mouth ** Arthropod mouthparts The mouthparts of arthropods have evolved into a number of forms, each adapted to a different style or mode of feeding. Most mouthparts represent modified, paired append ...

. The name "true bugs" is often limited to the suborder Heteroptera. Entomologists reserve the term ''bug'' for Hemiptera or Heteroptera,Gilbert Waldbauer. ''The Handy Bug Answer Book.'' Visible Ink, 1998
p. 1.
which does not include other arthropods or insects of other orders such as ants,

bees Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfam ...

beetles Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describe ...

, or

butterflies Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises ...

. In some variations of English, all terrestrial

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

s (including non-insect arachnids, and myriapods) also fall under the

colloquial Colloquialism (), also called colloquial language, everyday language or general parlance, is the linguistic style used for casual (informal) communication. It is the most common functional style of speech, the idiom normally employed in conve ...

understanding of ''bug''. Many insects with "bug" in their

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

, especially in

American English American English, sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. English is the most widely spoken language in the United States and in most circumstances ...

, belong to other orders; for example, the

lovebug The lovebug (''Plecia nearctica'') is a species of march fly found in parts of Central America and the southeastern United States, especially along the Gulf Coast. It is also known as the honeymoon fly or double-headed bug. During and after mat ...

is a

fly Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...

and the Maybug and

ladybug Coccinellidae () is a widespread family of small beetles ranging in size from . They are commonly known as ladybugs in North America and ladybirds in Great Britain. Some entomologists prefer the names ladybird beetles or lady beetles as th ...

are

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

s. The term is also occasionally extended to colloquial names for freshwater or marine

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean g ...

(e.g. Balmain bug, Moreton Bay bug, mudbug) and used by physicians and bacteriologists for disease-causing germs (e.g.

superbug Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. P ...

s). Most hemipterans feed on plants, using their sucking and piercing mouthparts to extract plant sap. Some are bloodsucking, or hematophagous, while others are predators that feed on other insects or small

invertebrates Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordat ...

. They live in a wide variety of habitats, generally terrestrial, though some are adapted to life in or on the surface of fresh water (e.g. pondskaters, water boatmen, giant water bugs). Hemipterans are hemimetabolous, with young nymphs that somewhat resemble adults. Many aphids are capable of

parthenogenesis Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and developmen ...

, producing young from unfertilised eggs; this helps them to reproduce extremely rapidly in favourable conditions. Humans have interacted with the Hemiptera for millennia. Some species, including many aphids, are significant

agricultural pests A pest is any animal or plant harmful to humans or human concerns. The term is particularly used for creatures that damage crops, livestock, and forestry or cause a nuisance to people, especially in their homes. Humans have modified the environ ...

, damaging crops by the direct action of sucking sap, but also harming them indirectly by being the vectors of serious viral diseases. Other species have been used for biological control of insect pests or of invasive plants. A few hemipterans have been cultivated for the extraction of dyestuffs such as

cochineal The cochineal ( , ; ''Dactylopius coccus'') is a scale insect in the suborder Sternorrhyncha, from which the natural dye carmine is derived. A primarily sessile parasite native to tropical and subtropical South America through North America ...

and

carmine Carmine ()also called cochineal (when it is extracted from the cochineal insect), cochineal extract, crimson lake, or carmine lake is a pigment of a bright-red color obtained from the aluminium complex derived from carminic acid. Specific code ...

, and for shellac. The

is a persistent parasite of humans, and some kissing bugs can transmit

Chagas disease Chagas disease, also known as American trypanosomiasis, is a tropical parasitic disease caused by ''Trypanosoma cruzi''. It is spread mostly by insects in the subfamily '' Triatominae'', known as "kissing bugs". The symptoms change over the co ...

. Cicadas have been used as food, and have appeared in literature since the ''

Iliad The ''Iliad'' (; grc, Ἰλιάς, Iliás, ; "a poem about Ilium") is one of two major ancient Greek epic poems attributed to Homer. It is one of the oldest extant works of literature still widely read by modern audiences. As with the ''Ody ...

'' in

Ancient Greece Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cu ...

Diversity

Hemiptera is the largest order of hemimetabolous insects (not undergoing complete metamorphosis; though some examples such as male

scale insects Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than t ...

do undergo a form of complete metamorphosis ), containing over 95,000 named species. Other insect orders with more species are all holometabolous, meaning they have a

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...

l stage and undergo complete

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

. The majority of species are terrestrial, including a number of important agricultural pests, but some are found in freshwater habitats. These include the water boatmen, backswimmers, pond skaters, and giant water bugs.

Taxonomy and phylogeny

Hemiptera belong to the

superorder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

Paraneoptera, which includes lice (

Psocodea Psocodea is a taxonomic group of insects comprising the bark lice, book lice and parasitic lice. It was formerly considered a superorder, but is now generally considered by entomologists as an order. Despite the greatly differing appearance of ...

), thrips ( Thysanoptera), and the true bugs of Hemiptera. Within Paraneoptera, Hemiptera is most closely related to the

sister clade In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

Thysanoptera. Fulgoroidea Crato Formation Brazil

The fossil record of hemipterans goes back to the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferou ...

(

Moscovian Moscovian may refer to: *An inhabitant of Moscow, the capital of Russia *Something of, from, or related to Moscow * Moscovian (Carboniferous), a stage of the Carboniferous in the ICS geologic timescale

As human parasites and disease vectors

is a modern-day tropical disease caused by ''Trypanosoma cruzi'' and transmitted by Triatominae, kissing bugs, so-called because they suck human blood from around the lips while a person sleeps. The

, ''Cimex lectularius'', is an external parasite of humans. It lives in bedding and is mainly active at night, feeding on human blood, generally without being noticed. Bed bugs Mating, mate by traumatic insemination; the male pierces the female's abdomen and injects his sperm into a secondary genital structure, the spermalege. The sperm travel in the female's blood (haemolymph) to female sperm storage, sperm storage structures (seminal conceptacles); they are released from there to fertilise her eggs inside her ovaries.Carayon, J. 1959 Insémination par "spermalège" et cordon conducteur de spermatozoids chez Stricticimex brevispinosus Usinger (Heteroptera, Cimicidae). Rev. Zool. Bot. Afr. 60, 81–104.

As food

Some larger hemipterans such as cicadas are used as food in Asian countries such as China, and they are much esteemed in Malawi and other African countries. Insects have a high protein content and good food conversion ratios, but most hemipterans are too small to be a useful component of the human diet. At least nine species of Hemiptera are eaten worldwide.

In art and literature

Cicadas have featured in literature since the time of Homer's ''

'', and as motifs in decorative art from the Chinese Shang dynasty (1766–1122 B.C.). They are described by Aristotle in his ''History of Animals'' and by Pliny the Elder in his ''Natural History (Pliny), Natural History''; their mechanism of sound production is mentioned by Hesiod in his poem ''Works and Days'' "when the Skolymus flowers, and the tuneful ''Tettix'' sitting on his tree in the weary summer season pours forth from under his wings his shrill song".

In mythology and folklore

Among the bugs, cicadas in particular have been used as money, in folk medicine, to forecast the weather, to provide song (in China), and in folklore and myths around the world.

Threats

Large-scale cultivation of the oil palm ''Elaeis guineensis'' in the Amazon basin damages freshwater habitats and reduces the diversity of aquatic and semi-aquatic Heteroptera. Climate change may be affecting the global migration of hemipterans including the potato leafhopper, ''Empoasca fabae''. Warming is correlated with the severity of potato leafhopper infestation, so increased warming may worsen infestations in future.

Notes

References

External links

Cladogram of Hemiptera at Tree of Life Project
{{Authority control Hemiptera, Insect orders Extant Pennsylvanian first appearances Taxa named by Carl Linnaeus Condylognatha