Xestia
Encyclopedia
Xestia is a genus of noctuid moths (family
Noctuidae). They are the type genus
of the tribe
Xestiini in subfamily Noctuinae
, though some authors merge this tribe with the Noctuini. Species
in this genus are commonly known as "clay", "dart" or "rustic
", but such names are commonplace among Noctuidae. Xestia moths have a wide distribution, though they most prominently occur in the Holarctic
.
With almost 200 species included at one time, Xestia was something of a "wastebin genus". But almost half of the traditional species are nowadays placed elsewhere (see below), and some of the remaining ones are liable to be assigned to another genus also. On the other hand, new moths that probably in fact belong into this genus are still being discovered regularly or so (e.g. X. hypographa
, which led to the 2002 transfer of X. ornata
from Eugraphe
to here). Thus, unless there are drastic taxonomic changes in the future, Xestia is likely to remain one of the larger noctuine genera.
while at rest however, with unmarked pale or dull brownish hindwings; they do not have metallic hues and few species possess obvious eyespots
.
This genus includes many species living at high latitude
s and altitudes, in tundra
and taiga
ecosystem
s. Some have two-year (semivoltine) life-cycle
s and only occur as adults every other year; typically the caterpillar
larva overwinters to pupa
te in spring, with the moths flying around midsummer, but some species eclose later, their moths flying from late summer into autumn. Xestia caterpillar
s are generally stout and cryptically
colored; in some species they have quite prominent dark lengthwise spots, but may e.g. be entirely green or whatever else gives best camouflage.
Some species' larvae are notoriously polyphagous, e.g. those the Setaceous Hebrew Character
(X. c-nigrum) whose food includes all sorts of core eudicots – including Solanaceae
and others which are poisonous to many herbivore
s – as well as some monocots. The latter are mainly Poaceae
however, and few other monocots are utilized by Xestia larvae in general. Ericaceae
, as well as Betulaceae
and Poaceae, are key foodplants for many of the high-latitude species. Gymnosperm
s are foodplants of secondary importance in this genus, but Pinaceae
form the mainstay or exclusive food of some species which occasionally become more than nuisance pests. Altogether, Xestia moths are only known as major pests within limited areas or in regard to specific plants, in which cases damage can be economically significant though.
Even though the larval foodplants of many Xestia species are not or insufficiently known, those on record are from all major lineages of core eudicots. Among the basal core eudicots, Caryophyllales
(especially Polygonaceae
) are particularly significant, of the asterids
the Asterales
(especially Asteraceae
), Ericales
(especially Ericaceae) and Lamiales
(especially Plantaginaceae
), and of the rosids
the Malpighiales
(numerous families) and Rosales
(especially Rosaceae
). Less important asterid order
s among Xestia foodplants are for example Dipsacales
, Gentianales
and Solanales
, of the rosids e.g. Fabales
, Fagales
, Malvales
, Myrtales
and Sapindales
. More basal (mes
)angiosperms do not seem to be significant as Xestia foodplants, at least not in temperate
and cooler regions.
As far as is known, Xestia adults are nocturnal or crepuscular
(except of course the high-latitude species
), but often attracted to lights at night. They general feed on flowers with relatively short or no corolla, and will also drink other sugary liquids.
and Pseudohermonassa
; whether other genera are accepted varies among authors; Estimata
, Hemigraphiphora and Perinaenia
are provisionally considered distinct here. "Xestia" versuta does not seem to belong in the present genus; it may be an aberrant member of Goniographa
, but until this is resolved it is here treated under its original name Eugraphe versuta.
Furthermore, a case for separation has in particular been made for Amathes (possibly including Agrotiphila), Lytaea, Megasema (possibly including Megarhomba), Segetia and Schoyenia (with Archanarta occasionally also separate), but these are here included in Xestia. Some of them are, however, recognized as subgenera, and if the genus is split further would be first to become elevated in rank again. There is no real good justification for either treatment, except that the lengthy process of a thorough revision of noctuine systematics
and taxonomy
has only progressed so far. H. Beck in 1996 published a comprehensive taxonomic catalogue, introducing
generic names for most European groups of (presumably) related species. While few of these seem to stand any chance ever to be widely recognized as distinct genera, this step is likely to have made available a generic name for any taxa that are eventually split from Xestia sensu stricto.
es. Some of these would presumably warrant recognition as subgenera if the present-day subgenera are split off; the subgeneric names that would apply are given (if known) in the addition to the species-group names.
About one-third of the species here included in Xestia are incertae sedis
(of unclear assignment). Among this group are a few species which are extremely little-known, having been described long ago but studied only once or twice since then.
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...
Noctuidae). They are 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...
of the tribe
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...
Xestiini in subfamily Noctuinae
Noctuinae
Noctuinae is a subfamily of the family Noctuidae. The larvae of many species feed on roots or stems of various grasses. Some are generalist feeders which makes them potential pests....
, though some authors merge this tribe with the Noctuini. 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...
in this genus are commonly known as "clay", "dart" or "rustic
Rustic
Rustic can refer to:*rural*pastoralIn zoology:* Rustic moths, various noctuid moths of subfamilies Hadeninae and Noctuinae, including** The Rustic, * The Rustic , a brush-footed butterfly...
", but such names are commonplace among Noctuidae. Xestia moths have a wide distribution, though they most prominently occur in the Holarctic
Holarctic
The Holarctic ecozone refers to the habitats found throughout the northern continents of the world as a whole. This region is divided into the Palearctic, consisting of Northern Africa and all of Eurasia, with the exception of Southeast Asia and the Indian subcontinent, and the Nearctic,...
.
With almost 200 species included at one time, Xestia was something of a "wastebin genus". But almost half of the traditional species are nowadays placed elsewhere (see below), and some of the remaining ones are liable to be assigned to another genus also. On the other hand, new moths that probably in fact belong into this genus are still being discovered regularly or so (e.g. X. hypographa
Xestia hypographa
Xestia hypographa is a moth of the Noctuidae family. It is only known from the north-western part of the Tien-Shan Mountains.The wingspan is 32-34 mm.-External links:*...
, which led to the 2002 transfer of X. ornata
Xestia ornata
Xestia ornata is a moth of the Noctuidae family. It is found from the northern Tien-Shan Mountains through the Pamirs and Hissar-Darwaz system to eastern Afghanistan .The wingspan is 32-37 mm.-External links:*...
from Eugraphe
Eugraphe
Eugraphe is a genus of noctuid moths . They belong to the tribe Xestiini of the typical noctuid subfamily Noctuinae, though some do not separate this tribe and include the genus in the Noctuini. It is closely related to Anagnorisma, Coenophila and Eugnorisma, and as it seems most closely to the...
to here). Thus, unless there are drastic taxonomic changes in the future, Xestia is likely to remain one of the larger noctuine genera.
Ecology
Xestia adults are usually of medium size and robust build, with stout hairy bodies and strong wings. Some are quite colorful moths, with bold lighter markings and hindwings in delicate yellowish, reddish or bluish hues. Generally, they are crypticCrypsis
In ecology, crypsis is the ability of an organism to avoid observation or detection by other organisms. It may be either a predation strategy or an antipredator adaptation, and methods include camouflage, nocturnality, subterranean lifestyle, transparency, and mimicry...
while at rest however, with unmarked pale or dull brownish hindwings; they do not have metallic hues and few species possess obvious eyespots
Eyespot (mimicry)
An eyespot is an eye-like marking. They are found on butterflies, reptiles, birds and fish. In members of the Felidae family , the white circular markings on the backs of the ears are termed ocelli, and they are functionally similar to eyespots in other animals.Eyespots may be a form of...
.
This genus includes many species living at high latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
s and altitudes, in tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
and taiga
Taiga
Taiga , also known as the boreal forest, is a biome characterized by coniferous forests.Taiga is the world's largest terrestrial biome. In North America it covers most of inland Canada and Alaska as well as parts of the extreme northern continental United States and is known as the Northwoods...
ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
s. Some have two-year (semivoltine) life-cycle
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
s and only occur as adults every other year; typically the caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
larva overwinters to 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...
te in spring, with the moths flying around midsummer, but some species eclose later, their moths flying from late summer into autumn. Xestia caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s are generally stout and cryptically
Crypsis
In ecology, crypsis is the ability of an organism to avoid observation or detection by other organisms. It may be either a predation strategy or an antipredator adaptation, and methods include camouflage, nocturnality, subterranean lifestyle, transparency, and mimicry...
colored; in some species they have quite prominent dark lengthwise spots, but may e.g. be entirely green or whatever else gives best camouflage.
Some species' larvae are notoriously polyphagous, e.g. those the Setaceous Hebrew Character
Setaceous Hebrew Character
The Setaceous Hebrew Character is a moth of the family Noctuidae. It is found in the Palearctic ecozone. It is a common species throughout Europe. It is also found in North America, from coast to coast across Canada and the northern United States to western Alaska. It occurs in the Rocky Mountains...
(X. c-nigrum) whose food includes all sorts of core eudicots – including Solanaceae
Solanaceae
Solanaceae are a family of flowering plants that include a number of important agricultural crops as well as many toxic plants. The name of the family comes from the Latin Solanum "the nightshade plant", but the further etymology of that word is unclear...
and others which are poisonous to many herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
s – as well as some monocots. The latter are mainly Poaceae
Poaceae
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
however, and few other monocots are utilized by Xestia larvae in general. Ericaceae
Ericaceae
The Ericaceae, commonly known as the heath or heather family, is a group of mostly calcifuge flowering plants. The family is large, with roughly 4000 species spread across 126 genera, making it the 14th most speciose family of flowering plants...
, as well as Betulaceae
Betulaceae
Betulaceae, or the Birch Family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams and hop-hornbeams, numbering about 130 species...
and Poaceae, are key foodplants for many of the high-latitude species. Gymnosperm
Gymnosperm
The gymnosperms are a group of seed-bearing plants that includes conifers, cycads, Ginkgo, and Gnetales. The term "gymnosperm" comes from the Greek word gymnospermos , meaning "naked seeds", after the unenclosed condition of their seeds...
s are foodplants of secondary importance in this genus, but Pinaceae
Pinaceae
Pinaceae are trees or shrubs, including many of the well-known conifers of commercial importance such as cedars, firs, hemlocks, larches, pines and spruces. The family is included in the order Pinales, formerly known as Coniferales. Pinaceae are supported as monophyletic by its protein-type sieve...
form the mainstay or exclusive food of some species which occasionally become more than nuisance pests. Altogether, Xestia moths are only known as major pests within limited areas or in regard to specific plants, in which cases damage can be economically significant though.
Even though the larval foodplants of many Xestia species are not or insufficiently known, those on record are from all major lineages of core eudicots. Among the basal core eudicots, Caryophyllales
Caryophyllales
Caryophyllales is an order of flowering plants that includes the cacti, carnations, amaranths, ice plants, and many carnivorous plants. Many members are succulent, having fleshy stems or leaves.-Description:...
(especially Polygonaceae
Polygonaceae
Polygonaceae is a family of flowering plants known informally as the "knotweed family" or "smartweed family"— "buckwheat family" in the United States. The name is based on the genus Polygonum and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name refers...
) are particularly significant, of the asterids
Asterids
In the APG II system for the classification of flowering plants, the name asterids refers to a clade .Most of the taxa belonging to this clade had been referred to the Asteridae in the Cronquist system and to the Sympetalae in earlier systems...
the Asterales
Asterales
Asterales is an order of dicotyledonous flowering plants that includes the composite family and its related families.The order is a cosmopolite, and includes mostly herbaceous species, although a small number of trees and shrubs are also present.The Asterales can be characterized on the...
(especially Asteraceae
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
), Ericales
Ericales
The Ericales are a large and diverse order of dicotyledons, including for example tea, persimmon, blueberry, Brazil nut, and azalea. The order includes trees and bushes, lianas and herbaceous plants. Together with ordinary autophytic plants, the Ericales include chlorophyll-deficient...
(especially Ericaceae) and Lamiales
Lamiales
Lamiales is an order in the asterid group of dicotyledonous flowering plants. It includes approximately 11,000 species divided into about 20 families...
(especially Plantaginaceae
Plantaginaceae
Plantaginaceae Juss. or plantain family, are a family of flowering plants in the order Lamiales. The type genus is Plantago L..In older classifications it used to be the only family of the order Plantaginales, but numerous phylogenetic studies, summarized by the Angiosperm Phylogeny Group, have...
), and of the rosids
Rosids
The rosids are members of a large clade of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms. The clade is divided into 16 to 20 orders, depending upon circumscription and classification. These orders, in turn, together comprise about 140 families...
the Malpighiales
Malpighiales
Malpighiales is one of the largest orders of flowering plants, containing about 16000 species, approximately 7.8% of the eudicots. The order is very diverse and hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification systems that are based only on...
(numerous families) and Rosales
Rosales
Rosales is an order of flowering plants. It is one of the four orders in the nitrogen fixing clade of the fabids and is sister to a clade consisting of Fagales and Cucurbitales. It contains about 7700 species, distributed into about 260 genera. Rosales comprises nine families, the type family...
(especially Rosaceae
Rosaceae
Rosaceae are a medium-sized family of flowering plants, including about 2830 species in 95 genera. The name is derived from the type genus Rosa. Among the largest genera are Alchemilla , Sorbus , Crataegus , Cotoneaster , and Rubus...
). Less important asterid 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...
s among Xestia foodplants are for example Dipsacales
Dipsacales
The Dipsacales are an order of flowering plants, included within the asterid group of dicotyledons.Under the Cronquist system, the order included Adoxaceae, Caprifoliaceae, Dipsacaceae, and Valerianaceae. Under the more recent Angiosperm Phylogeny Group system, the circumscription of the order is...
, Gentianales
Gentianales
Gentianales are an order of flowering plants, included within the asterid group of dicotyledons.The circumscription of Gentiales in the Cronquist system included a broadly defined Loganiaceae , Retziaceae, Gentianaceae, Saccifoliaceae, Apocynaceae, and Asclepiadaceae...
and Solanales
Solanales
The Solanales are an order of flowering plants, included in the asterid group of dicotyledons. Some older sources used the name Polemoniales for this order....
, of the rosids e.g. Fabales
Fabales
Fabales is an order of flowering plants. It is included in the rosid group of the eudicots in the Angiosperm Phylogeny Group II classification system...
, Fagales
Fagales
The Fagales are an order of flowering plants, including some of the best known trees. The order name is derived from genus Fagus, Beeches. They belong among the rosid group of dicotyledons...
, Malvales
Malvales
Malvales are an order of flowering plants. As circumscribed by APG II-system, it includes about 6000 species within nine families. The order is placed in the eurosids II, which are part of the eudicots....
, Myrtales
Myrtales
The Myrtales are an order of flowering plants placed as a basal group within the rosid group of dicotyledons...
and Sapindales
Sapindales
Sapindales is a botanical name for an order of flowering plants. Well-known members of Sapindales include citrus; maples, horse-chestnuts, lychees and rambutans; mangos and cashews; frankincense and myrrh; mahogany and neem....
. More basal (mes
Mesangiospermae
Mesangiospermae is a group of flowering plants, informally called "mesangiosperms". They are one of four clades of angiosperms. There are about 350,000 species of mesangiosperms...
)angiosperms do not seem to be significant as Xestia foodplants, at least not in 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...
and cooler regions.
As far as is known, Xestia adults are nocturnal or crepuscular
Crepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...
(except of course the high-latitude species
Midnight sun
The midnight sun is a natural phenomenon occurring in summer months at latitudes north and nearby to the south of the Arctic Circle, and south and nearby to the north of the Antarctic Circle where the sun remains visible at the local midnight. Given fair weather, the sun is visible for a continuous...
), but often attracted to lights at night. They general feed on flowers with relatively short or no corolla, and will also drink other sugary liquids.
Systematics and taxonomy
Several species formerly placed here are now in AgnorismaAgnorisma
Agnorisma is a genus of moths of the Noctuidae family. Agnorisma species were formerly included in the genus Xestia.-Species:*Agnorisma badinodis *Agnorisma bollii...
and Pseudohermonassa
Pseudohermonassa
Pseudohermonassa is a genus of moths of the Noctuidae family. Some species were formerly placed in Xestia.-Species:*Pseudohermonassa bicarnea *Pseudohermonassa flavotincta Pseudohermonassa is a genus of moths of the Noctuidae family. Some species were formerly placed in...
; whether other genera are accepted varies among authors; Estimata
Estimata
Estimata is a genus of moths of the Noctuidae family.-References:*...
, Hemigraphiphora and Perinaenia
Perinaenia
Perinaenia is a monotypic genus of moths of the Noctuidae family. It is here provisionally treated as separate from Xestia, though it seems closely related. Containing only the single species P...
are provisionally considered distinct here. "Xestia" versuta does not seem to belong in the present genus; it may be an aberrant member of Goniographa
Goniographa
Goniographa is a genus of noctuid moths . They belong to the tribe Xestiini of the typical noctuid subfamily Noctuinae, though some do not separate this tribe and include the genus in the Noctuini....
, but until this is resolved it is here treated under its original name Eugraphe versuta.
Furthermore, a case for separation has in particular been made for Amathes (possibly including Agrotiphila), Lytaea, Megasema (possibly including Megarhomba), Segetia and Schoyenia (with Archanarta occasionally also separate), but these are here included in Xestia. Some of them are, however, recognized as subgenera, and if the genus is split further would be first to become elevated in rank again. There is no real good justification for either treatment, except that the lengthy process of a thorough revision of noctuine systematics
Systematics
Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...
and taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
has only progressed so far. H. Beck in 1996 published a comprehensive taxonomic catalogue, introducing
Nomenclature
Nomenclature is a term that applies to either a list of names or terms, or to the system of principles, procedures and terms related to naming - which is the assigning of a word or phrase to a particular object or property...
generic names for most European groups of (presumably) related species. While few of these seem to stand any chance ever to be widely recognized as distinct genera, this step is likely to have made available a generic name for any taxa that are eventually split from Xestia sensu stricto.
Synonyms
Junior synonyms and other obsolete generic names for Xestia moths are:Species
The 110 or so species here placed in Xestia are divided among 5 subgenera. Two of these are further divided into groups, which are based on phenetic similarity however and may or may not form clades and/or species complexSpecies complex
A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...
es. Some of these would presumably warrant recognition as subgenera if the present-day subgenera are split off; the subgeneric names that would apply are given (if known) in the addition to the species-group names.
About one-third of the species here included in Xestia are 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...
(of unclear assignment). Among this group are a few species which are extremely little-known, having been described long ago but studied only once or twice since then.