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 ...
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 appropriate s ...
within groups such as the
cicada
The cicadas () are a superfamily, the Cicadoidea, of insects in the order Hemiptera (true bugs). They are in the suborder Auchenorrhyncha, along with smaller jumping bugs such as leafhoppers and froghoppers. The superfamily is divided into tw ...
s,
aphid
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...
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 exam ...
,
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 bug
The Pentatomoidea are a superfamily of insects in the Heteroptera suborder of the Hemiptera order. As Hemiptera, they share a common arrangement of sucking mouthparts. The roughly 7000 species under Pentatomoidea are divided into 21 families (16 ...
s. They range in size from to around , and share a common arrangement of piercing-sucking mouthparts. 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
Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Creta ...
terrestrial
Terrestrial refers to things related to land or the planet Earth.
Terrestrial may also refer to:
* Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...
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
arachnid
Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegar ...
s, and
myriapod
Myriapods () are the members of subphylum Myriapoda, containing arthropods such as millipedes and centipedes. The group contains about 13,000 species, all of them terrestrial.
The fossil record of myriapods reaches back into the late Silurian, ...
s) also fall under the
colloquial
Colloquialism (), also called colloquial language, everyday language or general parlance, is the style (sociolinguistics), linguistic style used for casual (informal) communication. It is the most common functional style of speech, the idiom norm ...
understanding of ''bug''.
Many insects with "bug" in their common name, 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 i ...
, 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 ...
Maybug
The cockchafer, colloquially called Maybug, Maybeetle, or doodlebug, is the name given to any of the European beetles of the genus ''Melolontha'', in the family Scarabaeidae.
Once abundant throughout Europe and a major pest in the periodical ...
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 they ...
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 gro ...
(e.g.
Balmain bug Balmain may refer to:
Places
* Balmain, New South Wales, a suburb of Sydney, Australia
* Electoral district of Balmain, an electoral division in New South Wales, Australia
* Balmain East, New South Wales, a suburb of Sydney, Australia
* Balmain Ho ...
,
Moreton Bay bug
''Thenus orientalis'' is a species of slipper lobster from the Indian and Pacific oceans.
''T. orientalis'' is known by a number of common names. The United Nations Food and Agriculture Organization prefers the name flathead lobster, while t ...
,
mudbug
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...
) and used by physicians and bacteriologists for disease-causing germs (e.g. superbugs).
Most hemipterans feed on plants, using their sucking and piercing mouthparts to extract
plant sap
Sap is a fluid transported in xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant.
Sap is distinct from latex, resin, or cell sap; it is a se ...
. Some are bloodsucking, or
hematophagous
Hematophagy (sometimes spelled haematophagy or hematophagia) is the practice by certain animals of feeding on blood (from the Greek words αἷμα ' "blood" and φαγεῖν ' "to eat"). Since blood is a fluid tissue rich in nutritious p ...
, while others are
predators
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
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
Hemimetabolism or hemimetaboly, also called incomplete metamorphosis and paurometabolism,McGavin, George C. ''Essential Entomology: An Order-by-Order Introduction''. Oxford: Oxford University Press, 2001. pp. 20. is the mode of development of certa ...
, with young
nymphs
A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ...
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
Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also i ...
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 Americ ...
shellac
Shellac () is a resin secreted by the female lac bug on trees in the forests of India and Thailand. It is processed and sold as dry flakes and dissolved in alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and ...
. The
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 ...
is a persistent parasite of humans, and some
kissing bug
The members of the Triatominae , a subfamily of the Reduviidae, are also known as conenose bugs, kissing bugs (so-called from their habit of feeding from around the mouths of people), or vampire bugs. Other local names for them used in The Ameri ...
Cicada
The cicadas () are a superfamily, the Cicadoidea, of insects in the order Hemiptera (true bugs). They are in the suborder Auchenorrhyncha, along with smaller jumping bugs such as leafhoppers and froghoppers. The superfamily is divided into tw ...
s 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 '' Odys ...
'' in
Ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean Sea, Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of Classical Antiquity, classical antiquity ( AD 600), th ...
.
Diversity
Hemiptera is the largest order of
hemimetabolous
Hemimetabolism or hemimetaboly, also called incomplete metamorphosis and paurometabolism,McGavin, George C. ''Essential Entomology: An Order-by-Order Introduction''. Oxford: Oxford University Press, 2001. pp. 20. is the mode of development of certa ...
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
Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago (or adult). Holometabolism is a synapomorphic trait of all insects in the superorder Endopterygota. ...
, 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 ...
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 ...
Paraneoptera
Paraneoptera or Acercaria is a superorder of insects which includes lice (bark lice and true lice), thrips, and hemipterans, the true bugs. It also includes the extinct order Permopsocida, known from fossils dating from the Early Permian to the ...
, 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
Thrips (order Thysanoptera) are minute (mostly long or less), slender insects with fringed wings and unique asymmetrical mouthparts. Different thrips species feed mostly on plants by puncturing and sucking up the contents, although a few are ...
), 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 t ...
Thysanoptera.
The
fossil record
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
of hemipterans goes back to the Carboniferous ( Moscovian). The oldest fossils are of the
Archescytinidae
Archescytinidae is an extinct family of fungus-feeding thrips belonging to the order Thysanoptera that was first defined by Robert John Tillyard in 1926. Tillyard, R. J. (1926). ''Kansas Permian Insects, Part 9: The Order Hemiptera.'' American J ...
from the
Lower Permian
The Cisuralian is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan an ...
and are thought to be basal to the
Auchenorrhyncha
The Auchenorrhyncha suborder of the Hemiptera contains most of the familiar members of what was called the "Homoptera" – groups such as cicadas, leafhoppers, treehoppers, planthoppers, and spittlebugs. The aphids and scale insects are the othe ...
Cicadomorpha
Cicadomorpha is an infraorder of the insect order Hemiptera which contains the cicadas, leafhoppers, treehoppers, and spittlebugs. There are approximately 35,000 described species worldwide. Distributed worldwide, all members of this group ar ...
appear in the
Upper Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...
, as do
Sternorrhyncha
The Sternorrhyncha suborder of the Hemiptera contains the aphids, whiteflies, and scale insects, groups which were traditionally included in the now-obsolete order "Homoptera". "Sternorrhyncha" refers to the rearward position of the mouthparts re ...
Aphids
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...
Triassic
The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...
. The
Coleorrhyncha
Coleorrhyncha or Peloridiomorpha, also known as moss bugs or beetle bugs, are a suborder of Hemiptera and represent an ancient lineage of moss-feeding insects. They show some similarities to the Heteroptera but have been considered distinct. It ha ...
extend back to the
Lower Jurassic
The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma&nb ...
Triassic
The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...
.
The present members of the order Hemiptera (sometimes referred to as Rhynchota) were historically placed into two orders, the so-called Homoptera and Heteroptera/Hemiptera, based on differences in wing structure and the position of the
rostrum
Rostrum may refer to:
* Any kind of a platform for a speaker:
**dais
**pulpit
* Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects
* Rostrum (ship), a form of bow on naval ships
* Ros ...
. The order is now divided into four suborders, after the "Homoptera" were established as paraphyletic (now the
Auchenorrhyncha
The Auchenorrhyncha suborder of the Hemiptera contains most of the familiar members of what was called the "Homoptera" – groups such as cicadas, leafhoppers, treehoppers, planthoppers, and spittlebugs. The aphids and scale insects are the othe ...
and the
Sternorrhyncha
The Sternorrhyncha suborder of the Hemiptera contains the aphids, whiteflies, and scale insects, groups which were traditionally included in the now-obsolete order "Homoptera". "Sternorrhyncha" refers to the rearward position of the mouthparts re ...
).
The below
cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...
shows Hemiptera's placement within
Paraneoptera
Paraneoptera or Acercaria is a superorder of insects which includes lice (bark lice and true lice), thrips, and hemipterans, the true bugs. It also includes the extinct order Permopsocida, known from fossils dating from the Early Permian to the ...
, as well as how Hemiptera's four suborders are related. English names are given in parentheses where possible.
Biology
Mouthparts
The defining feature of hemipterans is their "beak" in which the modified
mandibles
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...
and
maxillae
The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...
form a "stylet" which is sheathed within a modified labium. The stylet is capable of piercing tissues and sucking liquids, while the labium supports it. The stylet contains a channel for the outward movement of saliva and another for the inward movement of liquid food. A salivary pump drives saliva into the prey; a cibarial pump extracts liquid from the prey. Both pumps are powered by substantial dilator muscles in the head. The beak is usually folded under the body when not in use. The diet is typically
plant sap
Sap is a fluid transported in xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant.
Sap is distinct from latex, resin, or cell sap; it is a se ...
, but some hemipterans such as
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 exam ...
are
predators
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
.
Both herbivorous and predatory hemipterans inject
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
s to begin digestion extra-orally (before the food is taken into the body). These enzymes include
amylase
An amylase () is an enzyme that catalyses the hydrolysis of starch (Latin ') into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of ...
polygalacturonase
Endo-polygalacturonase (EC 3.2.1.15, pectin depolymerase, pectolase, pectin hydrolase, and poly-α-1,4-galacturonide glycanohydrolase; systematic name (1→4)-α-D-galacturonan glycanohydrolase (endo-cleaving)) is an enzyme that hydrolyzes the α- ...
proteinase
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalysis, catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurri ...
s to break down proteins.
Although the Hemiptera vary widely in their overall form, their mouthparts form a distinctive "rostrum". Other insect orders with mouthparts modified into anything like the rostrum and stylets of the Hemiptera include some
Phthiraptera
Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a result of ...
, but for other reasons they generally are easy to recognize as non-hemipteran. Similarly, the mouthparts of Siphonaptera, some Diptera and
Thysanoptera
Thrips (order Thysanoptera) are minute (mostly long or less), slender insects with fringed wings and unique asymmetrical mouthparts. Different thrips species feed mostly on plants by puncturing and sucking up the contents, although a few are ...
superficially resemble the rostrum of the Hemiptera, but on closer inspection the differences are considerable. Aside from the mouthparts, various other insects can be confused with Hemiptera, but they all have biting mandibles and maxillae instead of the rostrum. Examples include
cockroach
Cockroaches (or roaches) are a Paraphyly, paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are we ...
es and psocids, both of which have longer, many-segmented antennae, and some
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, but these have fully hardened forewings which do not overlap.
Wing structure
The
forewings
Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments (the mesothorax and metathorax), and the two pairs are often referred to as the forewings and hindwi ...
of Hemiptera are either entirely membranous, as in the
Sternorrhyncha
The Sternorrhyncha suborder of the Hemiptera contains the aphids, whiteflies, and scale insects, groups which were traditionally included in the now-obsolete order "Homoptera". "Sternorrhyncha" refers to the rearward position of the mouthparts re ...
and
Auchenorrhyncha
The Auchenorrhyncha suborder of the Hemiptera contains most of the familiar members of what was called the "Homoptera" – groups such as cicadas, leafhoppers, treehoppers, planthoppers, and spittlebugs. The aphids and scale insects are the othe ...
, or partially hardened, as in most Heteroptera. The name "Hemiptera" is from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
('; "half") and ('; "wing"), referring to the forewings of many heteropterans which are hardened near the base, but membranous at the ends. Wings modified in this manner are termed ''hemelytra'' (singular: ''hemelytron''), by analogy with the completely hardened
elytra
An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alterna ...
of
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, and occur only in the suborder Heteroptera. In all suborders, the hindwings – if present at all – are entirely membranous and usually shorter than the forewings. The forewings may be held "roofwise" over the body (typical of
Sternorrhyncha
The Sternorrhyncha suborder of the Hemiptera contains the aphids, whiteflies, and scale insects, groups which were traditionally included in the now-obsolete order "Homoptera". "Sternorrhyncha" refers to the rearward position of the mouthparts re ...
and
Auchenorrhyncha
The Auchenorrhyncha suborder of the Hemiptera contains most of the familiar members of what was called the "Homoptera" – groups such as cicadas, leafhoppers, treehoppers, planthoppers, and spittlebugs. The aphids and scale insects are the othe ...
), or held flat on the back, with the ends overlapping (typical of Heteroptera). The antennae in Hemiptera typically consist of four or five segments, although they can still be quite long, and the tarsi of the
legs
A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ...
have two or three segments.
Sound production
Many hemipterans can produce sound for communication. The "song" of male cicadas, the loudest of any insect, is produced by
tymbal
The tymbal (or timbal) is the corrugated exoskeletal structure used to produce sounds in insects. In male cicadas, the tymbals are membranes in the abdomen, responsible for the characteristic sound produced by the insect. In tiger moths, the t ...
organs on the underside of the abdomen, and is used to attract mates. The tymbals are drumlike disks of cuticle, which are clicked in and out repeatedly, making a sound in the same way as popping the metal lid of a jam jar in and out.
Stridulatory sounds are produced among the aquatic Corixidae and
Notonectidae
Notonectidae is a cosmopolitan family of aquatic insects in the order Hemiptera, commonly called backswimmers because they swim "upside down" (inverted). They are all predators and typically range from in length. They are similar in appearance t ...
(backswimmers) using tibial combs rubbed across rostral ridges.
Life cycle
Hemipterans are
hemimetabolous
Hemimetabolism or hemimetaboly, also called incomplete metamorphosis and paurometabolism,McGavin, George C. ''Essential Entomology: An Order-by-Order Introduction''. Oxford: Oxford University Press, 2001. pp. 20. is the mode of development of certa ...
, meaning that they do not undergo metamorphosis, the complete change of form between a
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
...
l phase and an adult phase. Instead, their young are called
nymphs
A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ...
, and resemble the adults to a greater or lesser degree. The nymphs moult several times as they grow, and each
instar
An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...
resembles the adult more than the previous one. Wing buds grow in later stage nymphs; the final transformation involves little more than the development of functional wings (if they are present at all) and functioning sexual organs, with no intervening
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 as in
holometabolous
Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago (or adult). Holometabolism is a synapomorphic trait of all insects in the superorder Endopterygota. ...
insects.
Parthenogenesis and viviparity
Many
aphid
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...
s are
parthenogenetic
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 ...
during part of the life cycle, such that females can produce unfertilized eggs, which are
clones
Clone or Clones or Cloning or Cloned or The Clone may refer to:
Places
* Clones, County Fermanagh
* Clones, County Monaghan, a town in Ireland
Biology
* Clone (B-cell), a lymphocyte clone, the massive presence of which may indicate a pathologi ...
of their mother. All such young are females (
thelytoky
Thelytoky (from the Greek ''thēlys'' "female" and ''tokos'' "birth") is a type of parthenogenesis in which females are produced from unfertilized eggs, as for example in aphids. Thelytokous parthenogenesis is rare among animals and reported in a ...
), so 100% of the population at these times can produce more offspring. Many species of aphid are also
viviparous
Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the ...
: the young are born live rather than laid as eggs. These adaptations enable aphids to reproduce extremely rapidly when conditions are suitable.
Locomotion
Hemipterans make use of a variety of modes of
locomotion
Locomotion means the act or ability of something to transport or move itself from place to place.
Locomotion may refer to:
Motion
* Motion (physics)
* Robot locomotion, of man-made devices
By environment
* Aquatic locomotion
* Flight
* Locomo ...
including swimming, skating on a water surface and jumping, as well as walking and flying like other insects.
Swimming and skating
Several families of Heteroptera are ''water bugs'', adapted to an aquatic lifestyle, such as the water boatmen (Corixidae), water scorpions (Nepidae), and backswimmers (Notonectidae). They are mostly predatory, and have legs adapted as
paddle
A paddle is a handheld tool with an elongated handle and a flat, widened distal end (i.e. the ''blade''), used as a lever to apply force onto the bladed end. It most commonly describes a completely handheld tool used to propel a human-powered w ...
s to help the animal move through the water. The pondskaters or water striders (Gerridae) are also associated with water, but use the surface tension of standing water to keep them above the surface; they include the sea skaters in the genus '' Halobates'', the only truly marine group of insects.
Marangoni propulsion
Marangoni effect
The Marangoni effect (also called the Gibbs–Marangoni effect) is the mass transfer along an interface between two phases due to a gradient of the surface tension. In the case of temperature dependence, this phenomenon may be called thermo-capill ...
propulsion exploits the change in surface tension when a soap-like surfactant is released on to a water surface, in the same way that a toy soap boat propels itself. Water bugs in the genus ''
Microvelia
''Microvelia'' is a genus of aquatic bugs in the family Veliidae
Veliidae is a family of gregarious predatory insects in the suborder Heteroptera. They are commonly known as riffle bugs, small water striders, or broad-shouldered water stri ...
'' (
Veliidae
Veliidae is a family of gregarious predatory insects in the suborder Heteroptera. They are commonly known as riffle bugs, small water striders, or broad-shouldered water striders because the segment immediately behind the head is wider than the ...
) can travel at up to 17 cm/s, twice as fast as they can walk, by this means.
Flight
Flight is well developed in the Hemiptera although mostly used for short distance movement and dispersal. Wing development is sometimes related to environmental conditions. In some groups of Hemiptera, there are variations of winged, short-winged, and wingless forms within a single species. This kind of polymorphism tends to be helpful when habitats are temporary with more energy put into reproduction when food is available and into dispersal through flight when food becomes scarce. In aphids, both winged and wingless forms occur with winged forms produced in greater numbers when food resources are depleted. Aphids and whiteflies can sometimes be transported very long distances by atmospheric updrafts and high altitude winds. Wing-length polymorphism is notably rare in tree-living Hemiptera.
Jumping
Many Auchenorrhyncha including representatives of the cicadas, leafhoppers, treehoppers, planthoppers, and froghoppers are adapted for jumping (saltation). Treehoppers, for example, jump by rapidly depressing their hind legs. Before jumping, the hind legs are raised and the femora are pressed tightly into curved indentations in the coxae. Treehoppers can attain a take-off velocity of up to 2.7 metres per second and an acceleration of up to 250 g. The instantaneous power output is much greater than that of normal muscle, implying that energy is stored and released to catapult the insect into the air. Cicadas, which are much larger, extend their hind legs for a jump in under a millisecond, again implying elastic storage of energy for sudden release.
Sedentary
Instead of relying on any form of locomotion, most Sternorrhyncha females are
sedentary
Sedentary lifestyle is a lifestyle type, in which one is physically inactive and does little or no physical movement and or exercise. A person living a sedentary lifestyle is often sitting or lying down while engaged in an activity like soci ...
or completely sessile, attached to their host plants by their thin feeding stylets which cannot be taken out of the plant quickly.
Ecological roles
Feeding modes
Herbivores
Most hemipterans are phytophagous, using their sucking and piercing mouthparts to feed on plant sap. These include cicadas, leafhoppers, treehoppers, planthoppers, froghoppers, aphids, whiteflies, scale insects, and some other groups. Some are monophages, being host specific and only found on one plant taxon, others are oligophages, feeding on a few plant groups, while others again are less discriminating polyphages and feed on many species of plant. The relationship between hemipterans and plants appears to be ancient, with piercing and sucking of plants evident in the
Early Devonian
The Early Devonian is the first of three epochs comprising the Devonian period, corresponding to the Lower Devonian series. It lasted from and began with the Lochkovian Stage , which was followed by the Pragian from and then by the Emsian, ...
period.
Hemipterans can dramatically cut the mass of affected plants, especially in major outbreaks. They sometimes also change the mix of plants by predation on seeds or feeding on roots of certain species. Some sap-suckers move from one host to another at different times of year. Many aphids spend the winter as eggs on a woody host plant and the summer as parthogenetically reproducing females on a herbaceous plant.
Phloem
Phloem (, ) is the living tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This transport process is c ...
sap, which has a higher concentration of sugars and nitrogen, is under positive pressure unlike the more dilute
xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...
sap. Most of the Sternorrhyncha and a number of Auchenorrhynchan groups feed on phloem. Phloem feeding is common in the Fulgoromorpha, most Cicadellidae and in the Heteroptera.
The Typhlocybine Cicadellids specialize in feeding on non-vascular
mesophyll tissue
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...
of leaves, which is more nutritious than the leaf epidermis. Most Heteroptera also feed on mesophyll tissue where they are more likely to encounter defensive secondary plant metabolites which often leads to the evolution of host specificity.
Obligate xylem feeding is a special habit that is found in the Auchenorrhyncha among Cicadoidea, Cercopoidea and in Cicadelline Cicadellids. Some phloem feeders may take to xylem sap facultatively, especially when facing dehydration. Xylem feeders tend to be polyphagous; to overcome the negative pressure of xylem requires a special cibarial pump.
Phloem feeding hemiptera typically have symbiotic micro-organisms in their gut that help to convert
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha a ...
s. Phloem feeders produce honeydew from their anus. A variety of organisms that feed on honeydew form symbiotic associations with phloem-feeders. Phloem sap is a sugary liquid low in amino acids, so insects have to process large quantities to meet their nutritional requirements. Xylem sap is even lower in amino acids and contains monosaccharides rather than sucrose, as well as organic acids and minerals. No digestion is required (except for the hydrolysis of sucrose) and 90% of the nutrients in the xylem sap can be utilised. Some phloem sap feeders selectively mix phloem and xylem sap to control the osmotic potential of the liquid consumed.
A striking adaptation to a very dilute diet is found in many hemipterans: a filter chamber, a part of the gut looped back on itself as a countercurrent exchanger, which permits nutrients to be separated from excess water. The residue, mostly water with sugars and amino acids, is quickly excreted as sticky "honey dew", notably from aphids but also from other Auchenorrhycha and Sternorrhyncha.
Some Sternorrhyncha including Psyllids and some aphids are gall formers. These sap-sucking hemipterans inject fluids containing plant hormones into the plant tissues inducing the production of tissue that covers to protects the insect and also act as sinks for nutrition that they feed on. The hackleberry gall psyllid for example, causes a woody gall on the leaf petioles of the hackleberry tree it infests, and the nymph of another psyllid produces a protective lerp out of hardened honeydew.
Predators
Most other hemipterans are
predatory
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
, feeding on other insects, or even small vertebrates. This is true of many aquatic species which are predatory, either as nymphs or adults. The predatory shield bug for example stabs caterpillars with its beak and sucks out the body fluids. The saliva of predatory heteropterans contains
digestive enzyme
Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption into the cells of the body. Digestive enzymes are found in the digestive tracts of anima ...
s such as
proteinase
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalysis, catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurri ...
and
phospholipase
A phospholipase is an enzyme that hydrolyzes phospholipids into fatty acids and other lipophilic substances. Acids trigger the release of bound calcium from cellular stores and the consequent increase in free cytosolic Ca2+, an essential step in ...
, and in some species also
amylase
An amylase () is an enzyme that catalyses the hydrolysis of starch (Latin ') into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of ...
. The mouthparts of these insects are adapted for predation. There are toothed stylets on the mandibles able to cut into and abrade tissues of their prey. There are further stylets on the maxillae, adapted as tubular canals to inject saliva and to extract the pre-digested and liquified contents of the prey.
Some species attack pest insects and are used in biological control. One of these is the spined soldier bug (''Podisus maculiventris'') that sucks body fluids from larvae of the
Colorado beetle
The Colorado potato beetle (''Leptinotarsa decemlineata''), also known as the Colorado beetle, the ten-striped spearman, the ten-lined potato beetle, or the potato bug, is a major pest of potato crops. It is about long, with a bright yellow/o ...
and the
Mexican bean beetle
The Mexican bean beetle (''Epilachna varivestis'') is a species of lady beetle that can be an agricultural pest. It is one of the few North American lady beetles that feed on plants rather than other insects. It is found throughout Mexico and ...
.
Haematophagic "parasites"
A few hemipterans are haematophagic (often described as "
parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
s"), feeding on the blood of larger animals. These include bedbugs and the triatomine
kissing bug
The members of the Triatominae , a subfamily of the Reduviidae, are also known as conenose bugs, kissing bugs (so-called from their habit of feeding from around the mouths of people), or vampire bugs. Other local names for them used in The Ameri ...
s of the assassin bug family
Reduviidae
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 exampl ...
, which can transmit the dangerous '' Chagas disease''. The first known hemipteran to feed in this way on vertebrates was the extinct assassin bug '' Triatoma dominicana'' found fossilized in
amber
Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In ...
and dating back about twenty million years. Faecal pellets fossilised beside it show that it transmitted a disease-causing ''
Trypanosoma
''Trypanosoma'' is a genus of kinetoplastids (class Trypanosomatidae), a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Sarcomastigophora. The name is derived from the Greek ''trypano-'' ( ...
'' and the amber included hairs of the likely host, a
bat
Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most ...
.
As symbionts
Some species of
ant
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...
protect and farm aphids (Sternorrhyncha) and other sap-sucking hemipterans, gathering and eating the honeydew that these hemipterans secrete. The relationship is mutualistic, as both ant and aphid benefit. Ants such as the yellow anthill ant, '' Lasius flavus'', breed aphids of at least four species, ''Geoica utricularia'', ''Tetraneura ulmi'', ''Forda marginata'' and ''Forda formicaria'', taking eggs with them when they found a new colony; in return, these aphids are obligately associated with the ant, breeding mainly or wholly asexually inside anthills. Ants may also protect the plant bugs from their natural enemies, removing the eggs of predatory beetles and preventing access by parasitic wasps.
Some leafhoppers (Auchenorrhyncha) are similarly "milked" by ants. In the Corcovado rain forest of Costa Rica, wasps compete with ants to protect and milk leafhoppers; the leafhoppers preferentially give more honeydew, more often, to the wasps, which are larger and may offer better protection.
As prey: defences against predators and parasites
Hemiptera form prey to predators including vertebrates, such as birds, and other invertebrates such as ladybirds. In response, hemipterans have evolved
antipredator adaptation
Anti-predator adaptations are mechanisms developed through evolution that assist prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, namely by avo ...
s. ''
Ranatra
''Ranatra'' is a genus of slender predatory insects of the family Nepidae, known as water scorpions or water stick-insects. There are around 100 ''Ranatra'' species found in freshwater habitats around the world, both in warm and temperate regions ...
'' may feign death (
thanatosis
Apparent death, colloquially known as playing dead, feigning death, or playing possum, is a behavior in which animals take on the appearance of being dead. It is an immobile state most often triggered by a predatory attack and can be found in a ...
toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...
fluids to ward off arthropod predators; some Pentatomidae such as '' Dolycoris'' are able to direct these fluids at an attacker. Toxic
cardenolide
A cardenolide is a type of steroid. Many plants contain derivatives, collectively known as cardenolides, including many in the form of cardenolide glycosides (cardenolides that contain structural groups derived from sugars). Cardenolide glycoside ...
compounds are accumulated by the heteropteran ''
Oncopeltus fasciatus
''Oncopeltus fasciatus'', known as the large milkweed bug, is a medium-sized hemipteran (true bug) of the family Lygaeidae.Attisano, A. (2013)
Oosorption and migratory strategy of the milkweed bug,''Oncopeltus fasciatus. Animal Behaviour 86(3):65 ...
'' when it consumes
milkweeds
''Asclepias'' is a genus of herbaceous, perennial, flowering plants known as milkweeds, named for their latex, a milky substance containing cardiac glycosides termed cardenolides, exuded where cells are damaged. Most species are toxic to humans ...
, while the coreid stinkbug '' Amorbus rubiginosus'' acquires 2- hexenal from its food plant, ''Eucalyptus''. Some long-legged bugs
mimic
MIMIC, known in capitalized form only, is a former simulation computer language developed 1964 by H. E. Petersen, F. J. Sansom and L. M. Warshawsky of Systems Engineering Group within the Air Force Materiel Command at the Wright-Patterson AFB in ...
twigs, rocking to and fro to simulate the motion of a plant part in the wind. The nymph of the Masked hunter bug camouflages itself with sand grains, using its hind legs and tarsal fan to form a double layer of grains, coarser on the outside. The Amazon rain forest cicada '' Hemisciera maculipennis'' displays bright red
deimatic
Deimatic behaviour or startle display means any pattern of bluffing behaviour in an animal that lacks strong defences, such as suddenly displaying conspicuous eyespots, to scare off or momentarily distract a predator, thus giving the prey anim ...
flash coloration on its hindwings when threatened; the sudden contrast helps to startle predators, giving the cicada time to escape. The coloured patch on the hindwing is concealed at rest by an olive green patch of the same size on the forewing, enabling the insect to switch rapidly from cryptic to deimatic behaviour.
Some hemipterans such as firebugs have bold
aposematic
Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste o ...
warning coloration, often red and black, which appear to deter
passerine
A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...
birds. Many hemipterans including aphids, scale insects and especially the planthoppers secrete wax to protect themselves from threats such as fungi, parasitoidal insects and predators, as well as abiotic factors like desiccation. Hard waxy coverings are especially important in the sedentary Sternorrhyncha such as scale insects, which have no means of escaping from predators; other Sternorrhyncha evade detection and attack by creating and living inside plant galls. Nymphal Cicadoidea and Cercopoidea have glands attached to the
Malpighian tubule
The Malpighian tubule system is a type of excretory and osmoregulatory system found in some insects, myriapods, arachnids and tardigrades.
The system consists of branching tubules extending from the alimentary canal that absorbs solutes, water, ...
s in their proximal segment that produce mucopolysaccharides, which form the froth around spittlebugs, offering a measure of protection.
Parental care is found in many species of Hemiptera especially in members of the Membracidae and numerous Heteroptera. In many species of shield bug, females stand guard over their egg clusters to protect them from egg parasitoids and predators. In the aquatic Belostomatidae, females lay their eggs on the back of the male which guards the eggs. Protection provided by ants is common in the Auchenorrhyncha.
Interaction with humans
As pests
Although many species of Hemiptera are significant pests of crops and garden plants, including many species of
aphid
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...
and scale insects, other species are harmless. The damage done is often not so much the deprivation of the plant of its sap, but the fact that they transmit serious viral diseases between plants. They often produce copious amounts of honeydew which encourages the growth of
sooty mould
Sooty mold (also spelled sooty mould) is a collective term for different Ascomycete fungi, which includes many genera, commonly ''Cladosporium'' and ''Alternaria''. It grows on plants and their fruit, but also environmental objects, like fences, ...
citrus
''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is native to ...
fruit trees, the green peach aphid and other aphids which attack crops worldwide and transmit diseases, and jumping plant lice which are often host plant-specific and transmit diseases.
For pest control
Members of the families
Reduviidae
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 exampl ...
Nabidae
The insect family Nabidae contains the damsel bugs. There are over 500 species in 20 genera. They are soft-bodied, elongate, winged terrestrial predators. Many damsel bugs catch and hold prey with their forelegs, similar to mantids. They are c ...
are obligate predators. Some predatory species are used in biological pest control; these include various nabids, and even some members of families that are primarily phytophagous, such as the genus ''
Geocoris
''Geocoris'' is a genus of insects in the family Geocoridae (although in the past the geocorids were subsumed as a subfamily under the family " Lygaeidae"). Commonly known as big-eyed bugs, the species in ''Geocoris'' are beneficial predators, b ...
'' in the family
Lygaeidae
The Lygaeidae are a family in the Hemiptera (true bugs), with more than 110 genera in four subfamilies. The family is commonly referred to as seed bugs, and less commonly, milkweed bugs, or ground bugs. However, while many of the species feed on ...
. Other hemipterans are omnivores, alternating between a plant-based and an animal-based diet. For example, ''
Dicyphus hesperus
''Dicyphus hesperus'' is a species of true bug in the family Miridae. It is a generalist predator of other insects and also feeds on plant tissues. It is native to North America and has been used there in biological control of agricultural pest ...
'' is used to control
whitefly
Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described.
Description and taxonomy
The ...
on
tomato
The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...
es but also sucks sap, and if deprived of plant tissues will die even if in the presence of whiteflies.
Insect products
Other hemipterans have positive uses for humans, such as in the production of the dyestuff carmine (
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 Americ ...
). The FDA has created guidelines for how to declare when it has been added to a product. The scale insect ''
Dactylopius coccus
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 ( ...
'' produces the brilliant red-coloured carminic acid to deter predators. Up to 100,000 scale insects need to be collected and processed to make a kilogram (2.2 lbs) of cochineal dye. A similar number of lac bugs are needed to make a kilogram of
shellac
Shellac () is a resin secreted by the female lac bug on trees in the forests of India and Thailand. It is processed and sold as dry flakes and dissolved in alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and ...
, a brush-on colourant and wood finish. Additional uses of this traditional product include the waxing of citrus fruits to extend their shelf-life, and the coating of pills to moisture-proof them, provide slow-release or mask the taste of bitter ingredients.
As human parasites and disease vectors
Chagas disease is a modern-day tropical disease caused by ''
Trypanosoma cruzi
''Trypanosoma cruzi'' is a species of parasitic euglenoids. Among the protozoa, the trypanosomes characteristically bore tissue in another organism and feed on blood (primarily) and also lymph. This behaviour causes disease or the likelihood o ...
'' and transmitted by kissing bugs, so-called because they suck human blood from around the lips while a person sleeps.
The
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 ...
, ''Cimex lectularius'', is an external
parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
of humans. It lives in bedding and is mainly active at night, feeding on human blood, generally without being noticed. Bed bugs mate by
traumatic insemination
Traumatic insemination, also known as hypodermic insemination, is the mating practice in some species of invertebrates in which the male pierces the female's abdomen with his aedeagus and injects his sperm through the wound into her abdominal cav ...
; the male pierces the female's abdomen and injects his sperm into a secondary genital structure, the
spermalege
The spermalege (also known as the organ of BerleseSiva-Jothy, M. T. (2006) "Trauma, disease and collateral damage: conflict in cimicids," ''Philosophical Transactions of the Royal Society B,'' 361, 269–275.) is a special-purpose organ found in fe ...
. The sperm travel in the female's blood (
haemolymph
Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod (invertebrate) body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which ...
) to sperm storage structures (seminal conceptacles); they are released from there to fertilise her eggs inside her
ovaries
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...
.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
cicada
The cicadas () are a superfamily, the Cicadoidea, of insects in the order Hemiptera (true bugs). They are in the suborder Auchenorrhyncha, along with smaller jumping bugs such as leafhoppers and froghoppers. The superfamily is divided into tw ...
s 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
Homer (; grc, Ὅμηρος , ''Hómēros'') (born ) was a Greek poet who is credited as the author of the ''Iliad'' and the ''Odyssey'', two epic poems that are foundational works of ancient Greek literature. Homer is considered one of the ...
's ''
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 '' Odys ...
'', and as motifs in decorative art from the Chinese
Shang dynasty
The Shang dynasty (), also known as the Yin dynasty (), was a Chinese royal dynasty founded by Tang of Shang (Cheng Tang) that ruled in the Yellow River valley in the second millennium BC, traditionally succeeding the Xia dynasty and ...
(1766–1122 B.C.). They are described by
Aristotle
Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of ph ...
in his ''
History of Animals
''History of Animals'' ( grc-gre, Τῶν περὶ τὰ ζῷα ἱστοριῶν, ''Ton peri ta zoia historion'', "Inquiries on Animals"; la, Historia Animalium, "History of Animals") is one of the major texts on biology by the ancient Gr ...
'' and by
Pliny the Elder
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic ' ...
in his '' Natural History''; their mechanism of sound production is mentioned by
Hesiod
Hesiod (; grc-gre, Ἡσίοδος ''Hēsíodos'') was an ancient Greek poet generally thought to have been active between 750 and 650 BC, around the same time as Homer. He is generally regarded by western authors as 'the first written poet ...
in his poem ''
Works and Days
''Works and Days'' ( grc, Ἔργα καὶ Ἡμέραι, Érga kaì Hēmérai)The ''Works and Days'' is sometimes called by the Latin translation of the title, ''Opera et Dies''. Common abbreviations are ''WD'' and ''Op''. for ''Opera''. is a ...
'' "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
''Elaeis guineensis'' is a species of palm commonly just called oil palm but also sometimes African oil palm or macaw-fat. It is the principal source of palm oil. It is native to west and southwest Africa, specifically the area between Angola a ...
'' 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
''Empoasca fabae'' belongs to family Cicadellidae and genus Empoasca within order Hemiptera.”Lamp, W., D., Miranda, L., Culler & Alexander, L. (2011) “Host Suitability and Gas Exchange Response of Grapevines to Potato Leafhopper (Hemiptera: ...
''. Warming is correlated with the severity of potato leafhopper infestation, so increased warming may worsen infestations in future.