A woodlouse (plural woodlice) is an

isopod Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, an ...

crustacean from the

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...

The current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their name from often being found in old wood. The first woodlice were

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

isopods which are presumed to have colonised land in the

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

, though the oldest known fossils are from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

period. They have many

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

s and although often referred to as terrestrial isopods, some species live

semiterrestrial In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semiaquatic animals include: * Verte ...

ly or have recolonised aquatic environments. Woodlice in the families

Armadillidae Armadillidae is a family of woodlice (Oniscidea; terrestrial crustaceans), comprising around 80 genera and 700 species. It is the largest family of Oniscidea, and one of the most species-rich families of the entire Isopoda. Armadillids genera ...

Armadillidiidae Armadillidiidae is a family of woodlice, a terrestrial crustacean group in the order Isopoda. Unlike members of some other woodlice families, members of this family can roll into a ball, an ability they share with the outwardly similar but unre ...

Eubelidae Eubelidae is a family of isopods belonging to the order Isopoda. It contains the following genera: *'' Aethiopopactes'' Ferrara & Taiti, 1982 *'' Ambounia'' Dollfus, 1895 *'' Angaribia'' Barnard, 1932 *'' Ankaratridium'' Paulian de Félice, 1950 ...

Tylidae Tylidae is a family of woodlice. It contains approximately 27 species, all but one in the genus ''Tylos'', the other being ''Helleria brevicornis''. Together with the family Ligiidae Ligiidae is a family (biology), family of woodlouse, woodl ...

and some other genera can roll up into a roughly spherical shape ( conglobate) as a defensive mechanism; others have partial rolling ability, but most cannot conglobate at all. Woodlice have a basic

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

of a segmented, dorso-ventrally flattened body with seven pairs of

jointed legs The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip (anat ...

, specialised

appendage An appendage (or outgrowth) is an external body part, or natural prolongation, that protrudes from an organism's body. In arthropods, an appendage refers to any of the homologous body parts that may extend from a body segment, including anten ...

s for

respiration Respiration may refer to: Biology * Cellular respiration, the process in which nutrients are converted into useful energy in a cell ** Anaerobic respiration, cellular respiration without oxygen ** Maintenance respiration, the amount of cellula ...

and like other peracarids, females carry fertilised eggs in their marsupium, through which they provide developing

embryo An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

s with water, oxygen and nutrients. The immature young hatch as

manca The manca (plural: ''mancae'') is the post- larval juvenile in some crustaceans. The manca stage is the defining characteristic of a clade called Mancoida which comprises all the member of the Peracarida except the Amphipoda. Mancae closely resem ...

e and receive further maternal care in some species. Juveniles then go through a series of moults before reaching maturity. Oniscidea all

While the broader

phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

of the Oniscideans has not been settled, eleven

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

sections Section, Sectioning or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sig ...

are agreed on with 3,937 species validated in

scientific literature : ''For a broader class of literature, see Academic publishing.'' Scientific literature comprises scholarly publications that report original empirical and theoretical work in the natural and social sciences. Within an academic field, scient ...

in 2004 and 3,710 species in 2014 out of an estimated total of 5,000–7,000 species

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

worldwide. Key adaptations to

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 ...

life have led to a highly diverse set of animals; from the marine

littoral zone The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...

and subterranean lakes to arid deserts and desert slopes above sea-level, woodlice have established themselves in most terrestrial

biome A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...

s and represent the full range of transitional forms and

behaviours Behavior (American English) or behaviour (British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as well ...

for living on land. Woodlice are widely studied in the contexts of

evolutionary biology Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life fo ...

behavioural ecology Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when ...

and

nutrient cycling A nutrient cycle (or ecological recycling) is the movement and exchange of inorganic and organic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cycli ...

. They are popular as

terrarium A terrarium (plural: terraria or terrariums) is usually a sealable glass container containing soil and plants that can be opened for maintenance to access the plants inside; however, terraria can also be open to the atmosphere. Terraria are ofte ...

pet A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive appearances, intelligence, ...

s because of their varied colour and texture forms, conglobating ability and ease of care.

Common names

Common names for woodlice vary throughout the English-speaking world. A number of common names make reference to the fact that some species of woodlice can roll up into a ball. Other names compare the woodlouse to a pig. The collective noun is a quabble of woodlice. Common names include: *armadillo bug *billy baker (

South Somerset South Somerset is a local government district in Somerset, England. The South Somerset district covers an area of ranging from the borders with Devon, Wiltshire and Dorset to the edge of the Somerset Levels. It has a population of approximat ...

) *billy button (Dorset) *boat-builder (

Newfoundland Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

, Canada) *butcher boy or butchy boy (Australia, mostly around

Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...

) *carpenter or cafner (

Newfoundland and Labrador Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

, Canada) *carpet shrimp (Ryedale) *charlie pig (Norfolk, England) *cheeselog (

Reading Reading is the process of taking in the sense or meaning of Letter (alphabet), letters, symbols, etc., especially by Visual perception, sight or Somatosensory system, touch. For educators and researchers, reading is a multifaceted process invo ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

) *cheesey wig *cheesy bobs (

Guildford Guildford () is a town in west Surrey, around southwest of central London. As of the 2011 census, the town has a population of about 77,000 and is the seat of the wider Borough of Guildford, which had around inhabitants in . The name "Guildf ...

) *cheesy bug (

North West Kent North West Kent is a geographical area in Kent, a county in south-east England. The term North West Kent may refer to one or both of two distinct areas; one is entirely within the modern boundaries of Kent, whereas the other also contains parts of ...

, Gravesend, England) *cheesy lou (

Suffolk Suffolk () is a ceremonial county of England in East Anglia. It borders Norfolk to the north, Cambridgeshire to the west and Essex to the south; the North Sea lies to the east. The county town is Ipswich; other important towns include Lowes ...

) *cheesy papa (

Essex Essex () is a county in the East of England. One of the home counties, it borders Suffolk and Cambridgeshire to the north, the North Sea to the east, Hertfordshire to the west, Kent across the estuary of the River Thames to the south, and G ...

) *chiggy pig (

Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is ...

) *chisel pig *chucky pig (

Gloucestershire Gloucestershire ( abbreviated Glos) is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn and the entire Forest of Dean. The county town is the city of Gl ...

Herefordshire Herefordshire () is a county in the West Midlands of England, governed by Herefordshire Council. It is bordered by Shropshire to the north, Worcestershire to the east, Gloucestershire to the south-east, and the Welsh counties of Monmouthshire ...

) *chuggy pig *crawley baker (

Dorset Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset (unitary authority), Dors ...

) *daddy grampher (

North Somerset North Somerset is a unitary authorities of England, unitary district in Somerset, South West England. Whilst its area covers part of the Ceremonial counties of England, ceremonial county of Somerset, it is administered independently of the non ...

) *damp beetle (North East England) *doodlebug (also used for the larva of an

antlion The antlions are a group of about 2,000 species of insect in the neuropteran family Myrmeleontidae. They are known for the predatory habits of their larvae, which mostly dig pits to trap passing ants or other prey. In North America, the larvae ...

and for the

cockchafer 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 ye ...

) *fat pigs (

Cork Cork or CORK may refer to: Materials * Cork (material), an impermeable buoyant plant product ** Cork (plug), a cylindrical or conical object used to seal a container ***Wine cork Places Ireland * Cork (city) ** Metropolitan Cork, also known as G ...

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

), *gramersow (

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

) *granny grey (Wales) *granny grunter (Isle of Man) *grumper-pig (Bermuda) *hardback (Humberside, England) *hobbling Andrew (Oxfordshire, England) *hobby horse (Isle of Purbeck, Dorset, England) *hog-louse *horton bug (Deal, Kent, England) *humidity bug (Ontario, Canada) *jomits (Cloneganna) *menace (

Plymouth, Devon Plymouth () is a port city and unitary authority in South West England. It is located on the south coast of Devon, approximately south-west of Exeter and south-west of London. It is bordered by Cornwall to the west and south-west. Plymouth' ...

) *mochyn coed (tree pig), pryf lludw (ash bug), granny grey in

Wales Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...

*monkey-peas (

Kent Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces ...

, England) *pea bug (

Medway Medway is a unitary authority district and conurbation in Kent, South East England. It had a population of 278,016 in 2019. The unitary authority was formed in 1998 when Rochester-upon-Medway amalgamated with the Borough of Gillingham to for ...

, England) *peasie-bug (

, England) *pennysow (

Pembrokeshire Pembrokeshire ( ; cy, Sir Benfro ) is a Local government in Wales#Principal areas, county in the South West Wales, south-west of Wales. It is bordered by Carmarthenshire to the east, Ceredigion to the northeast, and the rest by sea. The count ...

, Wales) *piggy wig *pill bug (usually applied only to the genus ''Armadillidium'') *potato bug *roll up bug *roly-poly *saw bug (Dingwall, Nova Scotia) *scuttlebug (New Zealand) *slater (

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

Ulster Ulster (; ga, Ulaidh or ''Cúige Uladh'' ; sco, label= Ulster Scots, Ulstèr or ''Ulster'') is one of the four traditional Irish provinces. It is made up of nine counties: six of these constitute Northern Ireland (a part of the United King ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

and

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

) *sour bug (Cambridgeshire) *sow bug *water bug *wood bug (

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, Canada) *wood-louse

Description and life cycle

The woodlouse has a

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard ou ...

-like

exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the ...

, which it must progressively shed as it grows. The

moult In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...

takes place in two stages; the back half is lost first, followed two or three days later by the front. This method of moulting is different from that of most arthropods, which shed their cuticle in a single process. A female woodlouse will keep

fertilised Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...

eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

in a marsupium on the underside of her body, which covers the under surface of the thorax and is formed by overlapping plates attached to the bases of the first five pairs of legs. They hatch into offspring that look like small white woodlice curled up in balls, although initially without the last pair of legs. The mother then appears to "give birth" to her offspring. Females are also capable of reproducing asexually."How Now, Sow Bug?," Discover, August 1999, 68. Despite being

crustacean 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 group ...

s like

lobster Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ...

s or

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

s, woodlice are said to have an unpleasant taste similar to "strong urine".

Pillbugs and pill millipedes

Pillbugs (woodlice of the family

, also known as pill woodlice) can be confused with

pill millipede Pill millipedes are any members of two living (and one extinct) orders of millipedes, often grouped together into a single superorder, Oniscomorpha. The name Oniscomorpha refers to the millipedes' resemblance to certain woodlice (Oniscidea), also ...

s of the order

Glomerida Glomerida is an order of pill-millipedes found primarily in the Northern Hemisphere. They superficially resemble pill-bugs or woodlice, and can enroll into a protective ball. They have twelve body segments, 17 to 19 pairs of legs, and males hav ...

. Both of these groups of terrestrial segmented arthropods are about the same size. They live in very similar habitats, and they can both roll up into a ball. Pill millipedes and pillbugs appear superficially similar to the naked eye. This is an example of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

. Pill millipedes can be distinguished from woodlice on the basis of having two pairs of legs per body segment instead of one pair like all isopods. Pill millipedes have 12 to 13 body segments and about 18 pairs of legs, whereas woodlice have 11 segments and only seven pairs of legs. In addition, pill millipedes are smoother, and resemble normal millipedes in overall colouring and the shape of the segments. Gråsuggor (Isopoda) - Ystad-2020

Ecology

Many members of Oniscidea live in terrestrial, non-aquatic environments, breathing through

trachea The trachea, also known as the windpipe, is a Cartilage, cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends ...

-like lungs in their paddle-shaped hind legs (pleopods), called

pleopodal lungs Pleopodal lungs are an anatomical feature of terrestrial isopods and a component of their respiratory system. They are ancestrally derived from pleopodal gills, and they facilitate gas exchange on land. They perform a similar function as spiracl ...

. Woodlice need moisture because they rapidly lose water by

excretion Excretion is a process in which metabolic waste is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys, and skin. This is in contrast with secretion, where the substance may have specific tasks after lea ...

and through their

cuticle A cuticle (), or cuticula, is 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 "cuticle" are non- homologous, differing in their origin, structu ...

, and so are usually found in damp, dark places, such as under rocks and logs, although one species, the desert dwelling ''

Hemilepistus reaumuri ''Hemilepistus reaumuri'' is a species of woodlouse that lives in and around the deserts of North Africa and the Middle East, "the driest habitat conquered by any species of crustacean". It reaches a length of and a width of up to , and has sev ...

'', inhabits "the driest habitat conquered by any species of crustacean". They are usually

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

and are

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...

s, feeding mostly on dead plant matter. A few woodlice have returned to water. Evolutionary ancient species are amphibious, such as the marine-intertidal sea slater (''

Ligia oceanica ''Ligia oceanica'', the sea slater, common sea slater, or sea roach, is a littoral zone woodlouse, living on rocky seashores of the European North Sea and Atlantic coastlines. ''L. oceanica'' is oval, twice as long as broad, and may reach up to ...

''), which belongs to family Ligiidae. Other examples include some '' Haloniscus'' species from

(family

Scyphacidae Scyphacidae is a family of woodlice in the order Isopoda Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs ...

), and in the northern hemisphere several species of

Trichoniscidae Trichoniscidae are a family of isopod Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven ...

and '' Thailandoniscus annae'' (family Styloniscidae). Species for which aquatic life is assumed include '' Typhlotricholigoides aquaticus'' (Mexico) and '' Cantabroniscus primitivus'' (Spain). Dysdera crocata

Woodlice are eaten by a wide range of

insectivore A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores wer ...

s, including spiders of the genus ''

Dysdera ''Dysdera'' is a genus of woodlouse hunting spiders that was first described by Pierre André Latreille in 1804. They originated from Central Asia to Central Europe. The family has gained many common names from their individual species, includi ...

'', such as the

woodlouse spider The woodlouse spider (''Dysdera crocata'') is a species of spider that preys primarily upon woodlice. Other common names refer to variations on the common name of its prey, including woodlouse hunter, sowbug hunter, sowbug killer, pillbug hunter ...

''Dysdera crocata'', and

land planarian Geoplanidae is a family of flatworms known commonly as land planarians or land flatworms. These flatworms are mainly predators of other invertebrates, which they hunt, attack and capture using physical force and the adhesive and digestive proper ...

s of the genus ''

Luteostriata ''Luteostriata'' is a genus of land planarians from Brazil characterized by a yellow body with dark longitudinal stripes. Description The genus ''Luteostriata'' is characterized by the presence of a cephalic retractor muscle, which allows thos ...

'', such as ''

Luteostriata abundans ''Luteostriata abundans'' is a species of Brazilian land planarian in the subfamily Geoplaninae. It is a common species in human-disturbed areas in Brazil's southernmost state, Rio Grande do Sul. Description ''Luteostriata abundans'' is a ...

''. Woodlice are sensitive to agricultural

pesticide Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...

s, but can tolerate some

toxic heavy metal A toxic heavy metal is any relatively dense metal or metalloid that is noted for its potential toxicity, especially in environmental contexts. The term has particular application to cadmium, mercury and lead, all of which appear in the World He ...

s, which they accumulate in the

hepatopancreas The hepatopancreas, digestive gland or midgut gland is an organ of the digestive tract of arthropods and molluscs. It provides the functions which in mammals are provided separately by the liver and pancreas, including the production of digestive ...

. Thus they can be used as

bioindicator A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...

s of heavy metal pollution.

Evolutionary history

The oldest fossils of woodlice are known from the mid-Cretaceous around 100 million years ago, from amber deposits found in Spain, France and Myanmar, These include a specimen of living genus ''

Ligia ''Ligia'' is a genus of isopods, commonly known as rock lice or sea slaters. Most ''Ligia'' species live in tidal zone cliffs and rocky beaches, but there are several fully terrestrial species which occur in high-humidity environments. Ecolo ...

'' from the Charentese amber of France, the genus '' Myanmariscus'' from the

Burmese amber Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. The ...

of Myanmar, which belongs to the Synocheta and likely the

Styloniscidae Styloniscidae is a family of woodlice A woodlouse (plural woodlice) is an isopod crustacean from the polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their ...

, '' Eoligiiscus tarraconensis'' which belongs to the family

Ligiidae Ligiidae is a family (biology), family of woodlouse, woodlice, the only family in the infraorder Diplocheta. Its members are common on rocky shores, in similar habitats to those inhabited by species of the bristletail ''Petrobius'' and the crab ...

, '' Autrigoniscus resinicola'' which belongs to the family

, and ''

Heraclitus helenae Heraclitus of Ephesus (; grc-gre, Ἡράκλειτος , "Glory of Hera"; ) was an ancient Greek pre-Socratic philosopher from the city of Ephesus, which was then part of the Persian Empire. Little is known of Heraclitus's life. He wrote a ...

'' which possibly belongs to

Detonidae Detonidae is a family of woodlice in the order Isopoda. There are at least 3 genera and more than 30 described species in Detonidae. Genera These three genera belong to the family Detonidae: * ''Armadilloniscus'' Uljanin, 1875 * '' Deto'' Guéri ...

all from

Spanish amber Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Cana ...

, and indeterminate specimens Charentese amber. The widespread distribution and diversification apparent of woodlice in the mid-Cretaceous implies that the origin of woodlice predates the breakup of

Pangaea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...

, likely during the

As pests

Although woodlice, like

earthworms An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. Th ...

, are generally considered beneficial in gardens for their role in controlling certain pests, producing compost and overturning the soil, they have also been known to feed on cultivated plants, such as ripening

strawberries The garden strawberry (or simply strawberry; ''Fragaria × ananassa'') is a widely grown hybrid species of the genus '' Fragaria'', collectively known as the strawberries, which are cultivated worldwide for their fruit. The fruit is widely ap ...

and tender seedlings. Woodlice can also invade homes en masse in search of moisture and their presence can indicate dampness problems. They are not generally regarded as a serious household pest as they do not spread malady and do not damage sound wood or structures. They can be easily removed with the help of vacuum cleaners, chemical sprays, insect repellents, and insect killers, or by removing the damp.

As pets

Woodlice have become a popular, low-maintenance household pet for children as well as a hobby for invertebrate and insect enthusiasts or collectors.

Porcellionidae Porcellionidae is a terrestrial family of the order Isopoda. This family contains 530 species, found on every continent except Antarctica. The ventral plate of the thoracic exoskeleton flare out slightly over the legs. This "flare" is called t ...

(sowbugs) and

(pillbugs) are seen often as they are the most common terrestrial isopods in Europe and North America. The isopod community has many resources for the care of the species. Many sites sell isopods for starting a colony, and to keep a bioactive

vivarium A vivarium (Latin, literally for "place of life"; plural: ''vivaria'' or ''vivariums'') is an area, usually enclosed, for keeping and raising animals or plants for observation or research. Water-based vivaria may have open tops providing they a ...

clean. Isopods are also a popular species at reptile or invertebrate conventions either sold as pets or micro-feeders.

Morphs and varieties

Amongst those who keep woodlice as pets, many species are bred for a certain coloration or variety of a species and are often recognized by a nickname that corresponds with their variety. Popular varieties include Dalmatian (''

Porcellio scaber ''Porcellio scaber'' (otherwise known as the common rough woodlouse or simply rough woodlouse), is a species of woodlouse native to Europe but with a cosmopolitan distribution. They are often found in large numbers in most regions, with many spe ...

''), Dairy Cow (''

Porcellio laevis ''Porcellio laevis'' (Common name, commonly called the swift woodlouse, dairy cow isopod, or smooth slater in Australia) is a species of woodlouse in the genus ''Porcellio''. As the species epithet ''laevis'' as well as the vernacular name "swift ...

''), Montenegro (''

Armadillidium klugii ''Armadillidium klugii'' is a lesser-known, rare Balkan, Dalmatia-based species of woodlouse, most distinguished by its colouration which resembles the red markings of the Mediterranean black widow ''Latrodectus tredecimguttatus''. This is probab ...

''), Zebra (''Armadillidium maculatum''), Magic Potion (''

Armadillidium vulgare ''Armadillidium vulgare'', the common pill-bug, potato bug, common pill woodlouse, roly-poly, slater, doodle bug, or carpenter, is a widespread European species of woodlouse. It is the most extensively investigated terrestrial isopod species. ...

''), Powder Blue ''( Porcellionides pruinosus)'', Panda King and Rubber Ducky (''

Cubaris ''Cubaris'' is a genus of woodlouse, woodlice in the family Armadillidae. There are more than 100 described species in ''Cubaris''. Cubaris species have in average lower reproduction rates and higher lifespans than other genera of isopod. As p ...

'' sp.), Tricolor (''Merulanella'' sp.). The Rubber Ducky variety is currently to be one of the most desired and yet most expensive pillbug isopod to date, with a purchase of 6 individual specimens costing over one-hundred dollars. This popularity is likely due to its rarity and cute or innocent appearance of a duck face, having yellow bands across the back and front of its body; all ''

'' species have this duck-billed shape on the head, but the Rubber Ducky variety has a coincidental coloring that lines up perfectly with this shape. Many varieties also have sub-varieties that are even more rare or uncommon, such as the orange mutation or variant of Orange Dalmatian (Dalmatian), Powder Orange (Powder Blue), Pink Ducky (Rubber Ducky), and Orange Koi (Koi) which could be bred with by combining their solid orange variants with the variants in the parentheticals. Other sub-varieties include the Japanese line of Magic Potion, White Ducky, Champagne and Yellow versions of Zebra, Albinos and T-albinos, and many more. There are some terrestrial isopods, though very few, that have been known to be

parthenogenic 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 development ...

. More specifically, dwarf whites, but it is unclear whether other varieties such as dwarf purple produce the same. Because of this parthenogenesis, they reproduce quickly and can be great for use as pets or feeders in vivariums. Some coloration descriptions can be used to identify multiple species, such as Orange Dalmatian, a color-pattern combination seen in both ''

'' and ''

''. Orange Vigor or Tangerine (''

''), Peach (''

Armadillidium nasatum ''Armadillidium nasatum'' is a large, Western European-based species of woodlouse that has been introduced to North America, along with ''Armadillidium vulgare'' also found in other parts of Europe. Description ''Armadillidium nasatum'' can ...

''), Orange (''

''), Orange (''Armadillidium werneri''), Orange ('' Porcellio expansus''), Orange, Orange Ember, or Spanish Orange (''

''), Maple Orange (''

Oniscus asellus ''Oniscus asellus'', the common woodlouse, is one of the largest and most common species of woodlouse in the British Isles and Western and Northern Europe, growing to lengths of 16 mm and widths of 6 mm. Distribution The common woodlou ...

''), Kumquat (''Agabiformius lentus''), and Persimmon ('' Venezillo parvus'') are all simply orange varieties of their species, and when combined with other varieties of their species can make even more uncommon colorations unique to them. Some unique species of woodlouse include the spiny isopods, though not much is known about them and there are only a few of them easily accessible for purchase online. These occasionally include ''Cristarmadillidium muricatum'' and a species from Thailand often referred to as simply "Thailand Spiny".

In the British Isles

Classification

*Infraorder/Section Diplocheta **

*Infraorder Holoverticata *Section:

Tylida Tylidae is a family of woodlice. It contains approximately 27 species, all but one in the genus ''Tylos'', the other being ''Helleria brevicornis''. Together with the family Ligiidae Ligiidae is a family (biology), family of woodlouse, woodl ...

*Section:

Microcheta ''Mesoniscus'' is a genus of woodlice, placed in its own family, Mesoniscidae, and section, Microcheta. It contains two species – ''Mesoniscus alpicolus'' and ''Mesoniscus graniger'' – that live in Central and Eastern Europe, mostly in and a ...

** Mesoniscidae *Section: Synocheta **

Buddelundiellidae Trichoniscidae are a family of isopods (woodlice), including the most abundant British woodlouse, ''Trichoniscus pusillus''. Most species of woodlice that have returned to an aquatic or amphibian way of life belong to this family. Several species ...

** Schoebliidae **

** Titaniidae **

Turanoniscidae ''Turanoniscus'' is a monotypic genus of crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, kr ...

*Section: Crinocheta ** Agnaridae **

Alloniscidae ''Alloniscus'' is the sole genus in the woodlice family Alloniscidae. There are more than 20 described species in ''Alloniscus''. Species These 23 species belong to the genus ''Alloniscus'': * '' Alloniscus allspachi'' Nunomura, 2001 * '' Allon ...

Balloniscidae Balloniscidae is a family of crustaceans belonging to the order Isopoda. Genera: * ''Balloniscus'' Budde-Lund, 1908 * ''Plataoniscus'' Leistikow, 2001 * ''Plataoniscus'' Vandel, 1963 References

{{Taxonbar, from=Q10425528 Isopoda ...

** Bathytropidae ** Berytoniscidae **

Cylisticidae Cylisticidae is a family of woodlice in the order Isopoda. There are at least 4 genera and more than 60 described species in Cylisticidae. Genera These four genera belong to the family Cylisticidae: * '' Cylisticus'' Schnitzler, 1853 (53 specie ...

Delatorreiidae Delatorreidae is a family of woodlice A woodlouse (plural woodlice) is an isopod crustacean from the polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their ...

** Halophilosciidae ** Olibrinidae **

Oniscidae Oniscidae is a family of woodlice, including the common woodlouse '' Oniscus asellus''. Six genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hie ...

** Philosciidae ** Platyarthridae **

** Pudeoniscidae ** Rhyscotidae **

Scleropactidae Scleropactidae is a family (biology), family of woodlouse, woodlice, with a predominantly Gondwanan distribution. It contains the following genera: *''Adinda'' Budde-Lund, 1904 (18 species) *''Amazoniscus'' Lemos de Castro, 1967 (6 species) *''A ...

Spelaeoniscidae Spelaeoniscidae is a family of 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, am ...

** Stenoniscidae **

Tendosphaeridae Tendosphaeridae is a family of 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, am ...

** Trachelipodidae

Notes

References

Paul T. Harding & Stephen L. Sutton (1985). Woodlice in Britain and Ireland: distribution and habitat (PDF). Abbots Ripton, Huntingdon, Institute of Terrestrial Ecology. p. 151. ISBN 0-904282-85-6. accessed through the NERC Open Access Research Archive (NORA)

External links

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