Scutelleridae
Encyclopedia
Scutelleridae is a family
of true bugs
. They are commonly known as jewel bugs or metallic shield bugs due to their often brilliant coloration. They are also known as shield-backed bugs due to the enlargement of the last section of their thorax into a continuous shield over the abdomen and wings. This latter characteristic distinguishes them from most other families within Heteroptera
, and may lead to misidentification as a beetle
rather than a bug
. These insects feed on plant juices from a variety of different species, including some commercial crops. Closely related to stink bugs, they may also produce an offensive odour when disturbed. There are around 450 species
worldwide.
) because the shield-like enlarged last section of their thorax
(known as the scutellum, Latin
for "little shield") completely covers the abdomen
and the wings.
Despite their resemblance to beetle
s, jewel bugs are hemiptera
ns or true bugs. The scutellum is an extension of the thorax, unlike the elytra of beetles which are hardened forewings. As such, jewel bugs have four membranous wings underneath the scutellum in contrast to two in beetles. The scutellum in jewel bugs also does not have a division in the middle and thus does not 'split open' when they take flight like in beetles.
The heads of jewel bugs are triangular and the antennae have three to five segments. Like all heteropterans, jewel bugs are characterized by a segmented beak-like mouthpart (known as the rostrum). During feeding, jewel bugs inject proteolytic enzymes
in their saliva
into plants, digesting plant matter into a liquid form which they then suck up. The tarsus has three segments (tarsomeres).
. The colors often change or become duller when the specimens are dried, due to the topmost chitinous layer becoming opaque and obscuring the colors of the bottom layer. The colors can be restored by moistening the surfaces with water.
Iridescence
(or goniochromism) in jewel bugs like Poecilocoris lewisi are the result of structural coloration. Instead of pigments, the colors are caused by the interference, diffraction, or scattering of light by numerous tiny structures.
In Poecilocoris lewisi, multiple tiny conical protuberances around 900 nm in height and averaging at a diameter of 360 nm are scattered on the epicuticle
. These structures affect light passing through them, producing their oily-looking blue sheen (known as the Tyndall effect
or Mie scattering).
In other species like the African shield bug (Calidea panaethiopica), the dorsal cuticle
is dotted with tiny regularly spaced hemispherical cavities. The depressions act like Bragg mirrors
. When light hits the pitted surface, it gives off multiple relfections resulting in the distinctive two tone yellow-blue iridescence.
The colors and patterns on jewel bugs can vary significantly between instar
s and even within adults of a species.
Jewel bugs are also known to mimic the colors, patterns, and shape of other organisms for defensive purposes. An example is the yellow-spotted black Steganocerus multipunctatus which exhibits Müllerian mimicry
with the tortoise beetle
Chiridopsis suffriani.
The eggs are laid in compact clusters. They may be round or barrel-shaped with a lid or a cap at the top (known as the operculum). They also contain a ring of small protuberances near the cap called micropylar processes. They permit the passage of sperm into the egg for fertilization and enable gaseous exchange from within the egg and the outside world for the embryos. The eggs are white or cream colored when freshly laid but can change color as the embryo matures. When hatching, the prolarva (the advanced embryo) exit the egg by opening the lid through peristaltic movements
and with the help of a T-shaped internal structure in the egg (known as the egg burster).
Like all hemipterans, jewel bugs undergo incomplete metamorphosis
(hemimetaboly) and do not possess larva
l and pupa
l stages. Instead the adults develop from several stages (instar
s) of nymphs
(usually five) through successive moltings (ecdysis
). Nymphs resemble the adults except for size and the absence of wings. They can be of different coloration or patterns from adults.
Some species are known to exhibit parental care
of eggs and nymph
s. Notable examples of which are Cantao parentum, Pachycoris klugii, Pachycoris stalii, Pachycoris torridus, and Tectocoris diophthalmus
.
from dorsal abdominal or sternal exocrine gland
s are used to attract mates by certain species of jewel bugs. In certain genera (like Tectocoris, Psacasta, Odontoscelis, and Irochrotus), males possess special unicellular
gland
s in the abdomen known as the androconia (singular: androconium). They release sex pheromones when ruptured.
Females possess a spermatheca
, an ectodermal gland which opens into the oviduct
. These serve as storage for sperm
deposited by males. It contains glands which can nourish the spermatozoa until they can be released to fertilize eggs.
Male jewel bugs of the genus Hotea possess an unusually large, spiky, and heavily sclerotized
genitalia. They are used in a mating practice known as traumatic insemination
, a result of evolutionary sexual conflict
. Male Hotea bugs tear through the female reproductive ducts to deposit sperm, inflicting substantial damage to the female in the process.
s, aldehyde
s, and ester
s. Nymphs and adults often exhibit clustering behavior, being found in large numbers close to each other. This behavior is thought to have an evolutionary advantage. The more individuals present in an area, the stronger the odor of the chemicals released when the bugs are threatened. If this fails, stink bugs will react to threat by flying away or dropping to the ground.
zoologist William Elford Leach
in 1815.
Scutelleridae belongs to the order
Hemiptera
(true bugs), under the suborder Heteroptera
and infraorder Pentatomomorpha
. They are classified under the superfamily
Pentatomoidea. They were formerly classified as a subfamily of Pentatomidae
by George Willis Kirkaldy
in 1909. The earliest attempt to restore them to family status was in 1917 by Edward Payson Van Duzee
. Most authorities today regard it as a valid family group.
The family is composed of about 81 genera
and around 450 species worldwide. While the tribal
and subfamilial classifications remain unclear, they are divided into eight subfamilies sensu lato: Elvisurinae, Eurygastrinae, Hoteinae (sometimes classified under Pachycorinae), Odontoscelinae, Odontotarsinae, Pachycorinae, Scutellerinae, and Tectocorinae.
In phylogenetic
studies in 2008 by Grazia et al., Scutelleridae was shown to be consistently monophyletic
, basal
to Acanthosomatidae
, and distal to Plataspididae
and Parastrachiidae. Below is the morphological
unweighted tree
of the superfamily Pentatomoidea after Grazia et al. (2008).
s (also spelled as senn, soun, or shüne pests) or wheat bugs. The most economically important species of which are members of the genus Eurygaster.
Eurygaster integriceps
, in particular, is a very destructive pest of cereal
crops in North Africa
, the Balkans
, and western and central Asia
. Other scutellerids known under the name 'sunn pest' include Ventocoris fischeri and members of the genus Odontotarsus, among others. Methods of control for sunn pests have included biological pest control
, using wasp
s of the family Scelionidae
from the genera Trissolcus and Ooencyrtus.
The cotton harlequin bug (Tectocoris diophthalmus
) is also an important pest of cotton
crops and Hibiscus
.
fly
which preys on hemipterans, Trichopoda pennipes
was introduced to Hawaii
to control the invasive species
Nezara viridula
, the southern green stink bug. The fly now threatens native species of bugs in Hawaii as well, particularly the Koa bug (Coleotichus blackburniae, a jewel bug species notable for not possessing stink glands) which has now become rare.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of true bugs
Hemiptera
Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...
. They are commonly known as jewel bugs or metallic shield bugs due to their often brilliant coloration. They are also known as shield-backed bugs due to the enlargement of the last section of their thorax into a continuous shield over the abdomen and wings. This latter characteristic distinguishes them from most other families within Heteroptera
Heteroptera
Heteroptera is a group of about 40,000 species of insects in the Hemiptera. Sometimes called "true bugs", that name more commonly refers to Hemiptera as a whole, and "typical bugs" might be used as a more unequivocal alternative since among the Hemiptera the heteropterans are most consistently and...
, and may lead to misidentification as a beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
rather than a bug
Hemiptera
Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...
. These insects feed on plant juices from a variety of different species, including some commercial crops. Closely related to stink bugs, they may also produce an offensive odour when disturbed. There are around 450 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
worldwide.
Description
Jewel bugs are small to medium-sized oval-shaped bugs with a body length averaging at 5 to 20 mm (0.196850393700787 to 0.78740157480315 in). They can easily be distinguished from stink bugs (PentatomidaePentatomidae
Pentatomidae, Greek pente meaning five and tomos meaning section, is a family of insects belonging to order hemiptera that includes some of the stink bugs and shield bugs. Their antennae are 5-segmented, which gives the family its scientific name. Their bodies are usually shield-shaped...
) because the shield-like enlarged last section of their thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
(known as the scutellum, Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "little shield") completely covers the abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
and the wings.
Despite their resemblance to beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, jewel bugs are hemiptera
Hemiptera
Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...
ns or true bugs. The scutellum is an extension of the thorax, unlike the elytra of beetles which are hardened forewings. As such, jewel bugs have four membranous wings underneath the scutellum in contrast to two in beetles. The scutellum in jewel bugs also does not have a division in the middle and thus does not 'split open' when they take flight like in beetles.
The heads of jewel bugs are triangular and the antennae have three to five segments. Like all heteropterans, jewel bugs are characterized by a segmented beak-like mouthpart (known as the rostrum). During feeding, jewel bugs inject proteolytic enzymes
Protease
A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....
in their saliva
Saliva
Saliva , referred to in various contexts as spit, spittle, drivel, drool, or slobber, is the watery substance produced in the mouths of humans and most other animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands,...
into plants, digesting plant matter into a liquid form which they then suck up. The tarsus has three segments (tarsomeres).
Colors
Though some species are quite drab, the most conspicuous jewel bugs are often brilliantly colored, exhibiting a wide range of iridescent metallic hues that change with the view angle. The colors are the result of a combination of factors. Some species like Chrsyocoris stockerus and Scutellera nobilis display colors from multiple thin layers of pigmented chitinChitin
Chitin n is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world...
. The colors often change or become duller when the specimens are dried, due to the topmost chitinous layer becoming opaque and obscuring the colors of the bottom layer. The colors can be restored by moistening the surfaces with water.
Iridescence
Iridescence
Iridescence is generally known as the property of certain surfaces which appear to change color as the angle of view or the angle of illumination changes...
(or goniochromism) in jewel bugs like Poecilocoris lewisi are the result of structural coloration. Instead of pigments, the colors are caused by the interference, diffraction, or scattering of light by numerous tiny structures.
In Poecilocoris lewisi, multiple tiny conical protuberances around 900 nm in height and averaging at a diameter of 360 nm are scattered on the epicuticle
Arthropod cuticle
The cuticle forms the outer skeleton of arthropods, including insects.-Anatomy:The cuticle is made up of two layers; the epicuticle which is a thin and waxy water resistant outer layer and contains no chitin, and another layer under it called the procuticle...
. These structures affect light passing through them, producing their oily-looking blue sheen (known as the Tyndall effect
Tyndall effect
The Tyndall effect, also known as Tyndall scattering, is light scattering by particles in a colloid or particles in a fine suspension. It is named after the 19th century physicist John Tyndall. It is similar to Rayleigh scattering, in that the intensity of the scattered light depends on the fourth...
or Mie scattering).
In other species like the African shield bug (Calidea panaethiopica), the dorsal cuticle
Cuticle
A cuticle , or cuticula, is a term used for any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticles" are non-homologous; differing in their origin, structure, function, and chemical composition...
is dotted with tiny regularly spaced hemispherical cavities. The depressions act like Bragg mirrors
Distributed Bragg reflector
A distributed Bragg reflector is a reflector used in waveguides, such as optical fibers. It is a structure formed from multiple layers of alternating materials with varying refractive index, or by periodic variation of some characteristic of a dielectric waveguide, resulting in periodic variation...
. When light hits the pitted surface, it gives off multiple relfections resulting in the distinctive two tone yellow-blue iridescence.
The colors and patterns on jewel bugs can vary significantly between instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
s and even within adults of a species.
Jewel bugs are also known to mimic the colors, patterns, and shape of other organisms for defensive purposes. An example is the yellow-spotted black Steganocerus multipunctatus which exhibits Müllerian mimicry
Müllerian mimicry
Müllerian mimicry is a natural phenomenon when two or more harmful species, that may or may not be closely related and share one or more common predators, have come to mimic each other's warning signals...
with the tortoise beetle
Tortoise beetle
The tortoise beetles are an artificial grouping of tribes within the leaf beetle subfamily Hispinae. In past classifications, they have been variously placed as a family or a subfamily ; when it was recognized that this group was not monophyletic, it was split and the resulting tribes were...
Chiridopsis suffriani.
Ecology and life cycle
All jewel bugs feed on plants (phytophagous).The eggs are laid in compact clusters. They may be round or barrel-shaped with a lid or a cap at the top (known as the operculum). They also contain a ring of small protuberances near the cap called micropylar processes. They permit the passage of sperm into the egg for fertilization and enable gaseous exchange from within the egg and the outside world for the embryos. The eggs are white or cream colored when freshly laid but can change color as the embryo matures. When hatching, the prolarva (the advanced embryo) exit the egg by opening the lid through peristaltic movements
Peristalsis
Peristalsis is a radially symmetrical contraction and relaxation of muscles which propagates in a wave down the muscular tube, in an anterograde fashion. In humans, peristalsis is found in the contraction of smooth muscles to propel contents through the digestive tract. Earthworms use a similar...
and with the help of a T-shaped internal structure in the egg (known as the egg burster).
Like all hemipterans, jewel bugs undergo incomplete metamorphosis
Hemimetabolism
Hemimetabolism or hemimetaboly, also called incomplete metamorphosis, is a term used to describe the mode of development of certain insects that includes three distinct stages: the egg, nymph, and the adult stage, or imago. These groups go through gradual changes; there is no pupal stage...
(hemimetaboly) and do not possess larva
Larva
A larva 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 and pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
l stages. Instead the adults develop from several stages (instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
s) of nymphs
Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...
(usually five) through successive moltings (ecdysis
Ecdysis
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...
). Nymphs resemble the adults except for size and the absence of wings. They can be of different coloration or patterns from adults.
Some species are known to exhibit parental care
Parental investment
In evolutionary biology, parental investment is any parental expenditure that benefits one offspring at a cost to parents' ability to invest in other components of fitness...
of eggs and nymph
Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...
s. Notable examples of which are Cantao parentum, Pachycoris klugii, Pachycoris stalii, Pachycoris torridus, and Tectocoris diophthalmus
Tectocoris diophthalmus
Tectocoris diophthalmus, commonly known as the Hibiscus Harlequin Bug or Cotton Harlequin Bug, is a brightly coloured convex and rounded shield-shaped bug with a metallic sheen that grows to about 20 mm. Adult females are mostly orange and males are both blue and red or orange. The colours are...
.
Reproduction
Chemical secretionsPheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
from dorsal abdominal or sternal exocrine gland
Exocrine gland
Exocrine glands are a type of ductal glands that secrete their products into ducts that lead directly into the external environment...
s are used to attract mates by certain species of jewel bugs. In certain genera (like Tectocoris, Psacasta, Odontoscelis, and Irochrotus), males possess special unicellular
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
gland
Gland
A gland is an organ in an animal's body that synthesizes a substance for release of substances such as hormones or breast milk, often into the bloodstream or into cavities inside the body or its outer surface .- Types :...
s in the abdomen known as the androconia (singular: androconium). They release sex pheromones when ruptured.
Females possess a spermatheca
Spermatheca
The spermatheca , also called receptaculum seminis , is an organ of the female reproductive tract in insects, some molluscs, oligochaeta worms and certain other invertebrates and vertebrates...
, an ectodermal gland which opens into the oviduct
Oviduct
In non-mammalian vertebrates, the passageway from the ovaries to the outside of the body is known as the oviduct. The eggs travel along the oviduct. These eggs will either be fertilized by sperm to become a zygote, or will degenerate in the body...
. These serve as storage for sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
deposited by males. It contains glands which can nourish the spermatozoa until they can be released to fertilize eggs.
Male jewel bugs of the genus Hotea possess an unusually large, spiky, and heavily sclerotized
Sclerite
A sclerite is a hardened body part. The term is used in various branches of biology for various structures including hardened portions of sponges, but it is most commonly used for the hardened portions of arthropod exoskeletons....
genitalia. They are used in a mating practice known as traumatic insemination
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 penis and injects his sperm through the wound into her abdominal cavity . The sperm diffuse through the female's hemolymph,...
, a result of evolutionary sexual conflict
Sexual conflict
Sexual conflict occurs when the two sexes have conflicting optimal fitness strategies concerning reproduction, particularly the mode and frequency of mating, leading to an evolutionary arms race between males and females. The conflict encompasses the actions and behaviors of both sexes to influence...
. Male Hotea bugs tear through the female reproductive ducts to deposit sperm, inflicting substantial damage to the female in the process.
Defenses
Like stink bugs, a vast majority of jewel bugs, both adults and nymphs, are also capable of releasing pungent defensive chemicals from glands located on the sides of the thorax. Typical compounds exuded by jewel bugs include alcoholAlcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s, aldehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
s, and ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s. Nymphs and adults often exhibit clustering behavior, being found in large numbers close to each other. This behavior is thought to have an evolutionary advantage. The more individuals present in an area, the stronger the odor of the chemicals released when the bugs are threatened. If this fails, stink bugs will react to threat by flying away or dropping to the ground.
Classification and evolution
Scutellerids were first described by the EnglishEnglish people
The English are a nation and ethnic group native to England, who speak English. The English identity is of early mediaeval origin, when they were known in Old English as the Anglecynn. England is now a country of the United Kingdom, and the majority of English people in England are British Citizens...
zoologist William Elford Leach
William Elford Leach
William Elford Leach FRS was an English zoologist and marine biologist.Leach was born at Hoe Gate, Plymouth, the son of a solicitor. At the age of twelve he went to school in Exeter, studying anatomy and chemistry. By this time he was already collecting marine samples from Plymouth Sound and along...
in 1815.
Scutelleridae belongs to the order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Hemiptera
Hemiptera
Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...
(true bugs), under the suborder Heteroptera
Heteroptera
Heteroptera is a group of about 40,000 species of insects in the Hemiptera. Sometimes called "true bugs", that name more commonly refers to Hemiptera as a whole, and "typical bugs" might be used as a more unequivocal alternative since among the Hemiptera the heteropterans are most consistently and...
and infraorder Pentatomomorpha
Pentatomomorpha
Pentatomomorpha is an infraorder of insects in the true bug order . It unites such animals as the plant bugs , stink bugs , flat bugs , seed bugs , etc. They are closely related to the Cimicomorpha.-Systematics:5 superfamilies are usually placed in the Pentatomomorpha...
. They are classified under the superfamily
Superfamily
The term superfamily is used to describe several different concepts in different scientific fields:* Superfamily and Superfamily : a level of biological classification; redirects to Taxonomic rank...
Pentatomoidea. They were formerly classified as a subfamily of Pentatomidae
Pentatomidae
Pentatomidae, Greek pente meaning five and tomos meaning section, is a family of insects belonging to order hemiptera that includes some of the stink bugs and shield bugs. Their antennae are 5-segmented, which gives the family its scientific name. Their bodies are usually shield-shaped...
by George Willis Kirkaldy
George Willis Kirkaldy
George Willis Kirkaldy was an English, entomologist who specialised on Hemiptera. He was a Fellow of the Royal Entomological Society....
in 1909. The earliest attempt to restore them to family status was in 1917 by Edward Payson Van Duzee
Edward Payson Van Duzee
Edward Payson Van Duzee was an American entomologist noted for his work on Hemiptera. As of 1885, he was a librarian at Grosvenor Library of Buffalo New York for 28 years, and then relocated to California in 1912 where he took a position at Scripps Institute in La Jolla...
. Most authorities today regard it as a valid family group.
The family is composed of about 81 genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
and around 450 species worldwide. While the tribal
Tribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...
and subfamilial classifications remain unclear, they are divided into eight subfamilies sensu lato: Elvisurinae, Eurygastrinae, Hoteinae (sometimes classified under Pachycorinae), Odontoscelinae, Odontotarsinae, Pachycorinae, Scutellerinae, and Tectocorinae.
In phylogenetic
Phylogenetics
In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...
studies in 2008 by Grazia et al., Scutelleridae was shown to be consistently monophyletic
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
, basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
to Acanthosomatidae
Acanthosomatidae
Acanthosomatidae is a family of Hemiptera, commonly named “shield bugs,” for which Kumar in hisWorld revision recognizes 47 genera; now this number is 54 genera, with about 200 species,and is one of the least diversified families within Pentatomoidea.-Genera:...
, and distal to Plataspididae
Plataspididae
Plataspididae are a family of shield bugs native to the Eastern Hemisphere. One species, Megacopta cribraria, has recently become introduced and established in the southeastern United States, where it is a pest of soybeans....
and Parastrachiidae. Below is the morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
unweighted tree
Phylogenetic tree
A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics...
of the superfamily Pentatomoidea after Grazia et al. (2008).
Economic significance
Though most jewel bugs do little harm to crop plants, a few members of Scutelleridae are considered major agricultural pests. Together with some species of stink bugs, they are collectively known as sunn pestSunn pest
A sunn pest is an insect belonging to a group representing several genera of the 'shield bug' and 'stink bug' Families, with the species Eurygaster integriceps being the most economically important...
s (also spelled as senn, soun, or shüne pests) or wheat bugs. The most economically important species of which are members of the genus Eurygaster.
Eurygaster integriceps
Eurygaster integriceps
Eurygaster integriceps is a species of shield bug in the family Pentatomidae, commonly known as the sunn pest or corn bug. It is native to much of northern Africa, the Balkans and western and central Asia. It is a major pest of cereal crops especially wheat, barley and oats.-Morphology and...
, in particular, is a very destructive pest of cereal
Cereal
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...
crops in North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
, the Balkans
Balkans
The Balkans is a geopolitical and cultural region of southeastern Europe...
, and western and central Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. Other scutellerids known under the name 'sunn pest' include Ventocoris fischeri and members of the genus Odontotarsus, among others. Methods of control for sunn pests have included biological pest control
Biological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
, using wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
s of the family Scelionidae
Scelionidae
The Hymenopteran family Scelionidae is a very large cosmopolitan group of exclusively parasitoid wasps, mostly small , often black, often highly sculptured, with elbowed antennae that have an 9- or 10-segmented flagellum...
from the genera Trissolcus and Ooencyrtus.
The cotton harlequin bug (Tectocoris diophthalmus
Tectocoris diophthalmus
Tectocoris diophthalmus, commonly known as the Hibiscus Harlequin Bug or Cotton Harlequin Bug, is a brightly coloured convex and rounded shield-shaped bug with a metallic sheen that grows to about 20 mm. Adult females are mostly orange and males are both blue and red or orange. The colours are...
) is also an important pest of cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
crops and Hibiscus
Hibiscus
Hibiscus is a genus of flowering plants in the mallow family, Malvaceae. It is quite large, containing several hundred species that are native to warm-temperate, subtropical and tropical regions throughout the world...
.
Conservation
Biological methods of pest control have sometimes backfired. A parasitoidParasitoid
A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship that is in essence parasitic; unlike a true parasite, however, it ultimately sterilises or kills, and sometimes consumes, the host...
fly
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
which preys on hemipterans, Trichopoda pennipes
Trichopoda pennipes
Trichopoda pennipes is a fly in the family Tachinidae. The larvae are parasitoids of several true bugs, particularly squash bugs and leaf-footed bugs in the family Coreidae and stinkbugs in the familye Pentatomidae and it is used as a biological control agents for these agricultural pests...
was introduced to Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
to control the invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
Nezara viridula
Nezara viridula
Nezara viridula, commonly known as the southern green stink bug or green vegetable bug , is a plant-feeding stink bug. Although believed to have originated in Ethiopia, it can now be found around the world...
, the southern green stink bug. The fly now threatens native species of bugs in Hawaii as well, particularly the Koa bug (Coleotichus blackburniae, a jewel bug species notable for not possessing stink glands) which has now become rare.
See also
- Sunn pestSunn pestA sunn pest is an insect belonging to a group representing several genera of the 'shield bug' and 'stink bug' Families, with the species Eurygaster integriceps being the most economically important...