Piesmatidae is a small family

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...

, commonly called ash-grey leaf bugs. It contains a mere three living genera

Genera

Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

 with over 40 described 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...

 altogether. The Piesmatidae are distributed mostly in the temperate

Temperate

In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 Northern Hemisphere

Northern Hemisphere

The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

, with some occurring in Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

. A common species found throughout the Americas

Americas

The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

 is Piesma cinereum.

Ash-grey leaf bugs are small insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s, some 2-4 mm overall. The head, thorax

Thorax

The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...

 and the firm part of the wings are extensively dimpled. This resembles the similar pattern of the Tingidae

Tingidae

Tingidae is a family of very small [2-10 mm] insects in the order Hemiptera that are commonly referred to as lace bugs. This group is distributed worldwide with about 2,000 described species....

 of the infraorder Cimicomorpha

Cimicomorpha

Cimicomorpha is an infraorder of insects containing bugs....

, and was initially taken to signify a close relationship. It is due to convergent evolution

Convergent evolution

Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...

 however.

They feed on plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 sap, mostly of Chenopodiaceae

Chenopodiaceae

Chenopodiaceae were a family of flowering plants, also called the Goosefoot Family. They are now included within family Amaranthaceae. The vast majority of Chenopods are weeds, and many are salt and drought tolerant. A few food crops also belong to the family: spinach, beets, chard, quinoa, and...

 and Caryophyllaceae

Caryophyllaceae

The Caryophyllaceae, commonly called the pink family or carnation family, is a family of flowering plants. It is included in the dicotyledon order Caryophyllales in the APG III system, alongside 33 other families, including Amaranthaceae, Cactaceae and Polygonaceae...

. Piesma linnavouri' have been found on Acacia

Acacia

Acacia is a genus of shrubs and trees belonging to the subfamily Mimosoideae of the family Fabaceae, first described in Africa by the Swedish botanist Carl Linnaeus in 1773. Many non-Australian species tend to be thorny, whereas the majority of Australian acacias are not...

(Fabaceae

Fabaceae

The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...

. Mcateella' have been found on many host plants but mostly Acacia

Acacia

Acacia is a genus of shrubs and trees belonging to the subfamily Mimosoideae of the family Fabaceae, first described in Africa by the Swedish botanist Carl Linnaeus in 1773. Many non-Australian species tend to be thorny, whereas the majority of Australian acacias are not...

and Proteaceae

Proteaceae

Proteaceae is a family of flowering plants distributed in the Southern Hemisphere. The family comprises about 80 genera with about 1600 species. Together with the Platanaceae and Nelumbonaceae they make up the order Proteales. Well known genera include Protea, Banksia, Embothrium, Grevillea,...

. The host plants of Miespa remain unknown.

Systematics

There are only 3 unequivocally accepted extant genera

Genera

Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

 of Piesmatidae:

• Mcateella
• Miespa
• Piesma

Most of the approximately 40 named species are in the type genus

Type genus

In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...

 Piesma, from which the subgenera

Subgenus

In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...

 Afropiesma and Parapiesma are sometimes split off. The genus Thaicoris was for some time placed here, but it has more recently been suggested that it is a member of the Thaumastocoridae.

There are two fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 genera. Eopiesma from the earliest Eocene (about 55 mya) is still a very basal member of the family. Heissiana, found in Baltic

Baltic region

The terms Baltic region, Baltic Rim countries, and Baltic Rim refer to slightly different combinations of countries in the general area surrounding the Baltic Sea.- Etymology :...

 amber

Amber

Amber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...

 from the Eocene

Eocene

The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

 might be a northern relative of Mcateella and Miespa but given its distribution it might more comfortably be considered closely related to the ancestor of Eopiesma. From 2007-2009 Cretopiesma was placed within the family. Cretopiesma was found in mid-Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 amber

Amber

Amber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...

 from Myanmar

Myanmar

Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....

 and lived about 100 mya (million years ago) and was initially considered to be a promitive piesmatid but this has since been rejected.

The closest relatives of the Piesmatidae remain rather insufficiently determined. After the ash-grey leaf bugs were recognized as Pentatomomorpha, they were most often placed in the Lygaeoidea

Lygaeoidea

The Lygaeoidea are a sizeable superfamily of true bugs, containing the seed bugs and allies. The ash-gray leaf bug family , usually placed herein, might be closer to the Aradoidea....

 based on cladistic analysis, with their relatives variously presumed to be the Berytidae

Berytidae

Berytidae is a family of bugs, commonly called stilt bugs.One common genus in this family is Neides....

, Colobathristidae and Malcidae, or the peculiar, 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...

-like Psamminae, a subfamily of the Lygaeidae. For some time, the Psamminae were even included in the Piesmatidae.

Alternatively, the ash-grey leaf bugs were considered Pentatomomorpha incertae sedis

Incertae sedis

, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...

or placed in a monotypic

Monotypic

In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 superfamily Piesmatoidea with the discovery of Cretopiesma. However a cladistic analysis by Cassis ans Schuh rejected Cretopiesma from Piesmatidae and placed the genus in the family Aradoidea

Aradoidea

Aradoidea is a superfamily of true bugs. The Piesmatidae, usually placed in the Lygaeoidea, might also belong here....

.