Terrestrial-isopod
Guides
Alloniscus mirabilis
Wonderful Wracklouse
Alloniscus mirabilis is a terrestrial isopod (woodlouse) in the family Alloniscidae. The species epithet "mirabilis" (Latin for "wonderful" or "extraordinary") reflects its distinctive characteristics. As a member of the suborder Oniscidea, it is a fully terrestrial crustacean adapted to life on land. The species has been documented in North America with 81 observations recorded on iNaturalist.
Alloniscus perconvexus
Commando Isopod
Alloniscus perconvexus is a terrestrial isopod in the family Alloniscidae, commonly known as the Commando Isopod. It is a North American endemic with documented observations across the continent. The species belongs to a family of relatively large, robust woodlice that exhibit specialized adaptations for arid and semi-arid environments.
Androniscus
Androniscus is a genus of small woodlice in the family Trichoniscidae, established by Verhoeff in 1908. The genus includes the well-known species Androniscus dentiger, commonly called the rosy or pink woodlouse. Members of this genus are characterized by their small size, distinctive coloration, and association with calcareous environments. Some populations show cave-adapted ecology, particularly in the southern part of their range.
Armadillidium vulgare
common pill-bug, common pill woodlouse, roly-poly, potato bug, doodle bug, carpenter
Armadillidium vulgare is a terrestrial isopod native to Mediterranean Europe that has become one of the most widespread woodlouse species globally through human-mediated dispersal. It is the most extensively studied terrestrial isopod and serves as a model organism for research on mitochondrial genome evolution, desiccation resistance, and conglobation behavior. The species exhibits remarkable morphological plasticity, including numerous color morphs maintained through selective breeding in the pet trade.
Chaetophiloscia
Chaetophiloscia is a genus of small terrestrial isopods in the family Philosciidae, established by Verhoeff in 1908. The genus is native to the northern Mediterranean region, with at least two species documented: C. sicula, which has become invasive in North America and parts of Europe, and C. elongata, studied in North African coastal habitats. Species in this genus are characterized by their association with moist, anthropogenic, and coastal environments, and their capacity for rapid range expansion through human-mediated transport.
Cylisticus convexus
Curly Woodlouse
Cylisticus convexus, commonly known as the curly woodlouse, is a small terrestrial isopod first described by Charles De Geer in 1778. Native to Europe and Asia, it has been introduced to North Africa, North America, and South America. The species is notable for its ability to conglobate (roll into a ball) while retaining protruding antennae and uropods, and for possessing five pairs of pleopodal lungs—features that distinguish it from similar pillbugs.
Detonella papillicornis
woodlouse
Detonella papillicornis is a species of terrestrial isopod (woodlouse) in the family Detonidae. The species was first described by Richardson in 1904. It is one of relatively few documented species in the genus Detonella, a group of woodlice characterized by specific morphological features within the family Detonidae.
Ligidium blueridgensis
Ligidium blueridgensis is a terrestrial isopod species in the family Ligiidae, described in 1964 from specimens collected in the southern Blue Ridge Mountains. The species exhibits a disjunct distribution across multiple biogeographical barriers in Georgia, North Carolina, South Carolina, and Tennessee, with deeply divergent mitochondrial lineages suggesting long-term persistence and diversification in the region. It is one of several morphologically similar Ligidium species in the southern Appalachians.
Ligidium elrodii
Eastern Rockslater, rock slater
Ligidium elrodii is a terrestrial isopod species in the family Ligiidae, commonly known as the Eastern Rockslater. It is native to North America, with documented presence in both the United States and Canada. The species includes five recognized subspecies, described by Schultz in 1970 from various geographic locations. It belongs to a family of rock-dwelling woodlice adapted to moist, rocky microhabitats.
Miktoniscus medcofi
Small Alabama Sowbug
A small terrestrial isopod in the family Trichoniscidae, found in both North America and South America. This species belongs to a genus characterized by reduced body pigmentation and small size. It inhabits moist microhabitats in forested environments. The common name 'Small Alabama Sowbug' reflects its documented occurrence in the southeastern United States.
Niambia capensis
African Cape Isopod
Niambia capensis is a species of woodlouse in the family Platyarthridae, first described by Dollfus in 1895. It is native to Africa, with records from South Africa and Namibia, and has been introduced to North America. This terrestrial isopod belongs to the suborder Oniscidea, which contains the familiar pillbugs and sowbugs. The species represents one of the few documented cases of transoceanic dispersal in terrestrial isopods, likely through human-mediated transport.
Oniscidea
Woodlice, Pillbugs, Rock Slaters
Oniscidea is the suborder of terrestrial isopod crustaceans commonly known as woodlice, pillbugs, and rock slaters. This diverse group comprises over 5,000 described species that have successfully colonized land from ancestral marine isopod stock. They are characterized by a dorsoventrally flattened, segmented exoskeleton with seven pairs of walking legs, and occupy a wide range of habitats from forests and grasslands to caves and urban environments. Most species are nocturnal detritivores that play important roles in decomposition and nutrient cycling.
Oniscus
woodlice
Oniscus is a genus of terrestrial isopods (woodlice) in the family Oniscidae. The genus comprises five species with restricted distributions: three species are endemic to northwestern Iberia (O. ancarensis, O. galicianus, O. lusitanicus), one to the Pyrenees (O. simonii), and one species, O. asellus, is widespread across Europe and has been introduced to the Americas. O. asellus has been studied for its ability to fragment weathered polystyrene plastic into microplastics in laboratory settings.
Philoscia muscorum
Common Striped Woodlouse, Fast Woodlouse
Philoscia muscorum is a common European woodlouse notable for its rapid movement and distinctive appearance. It exhibits a unique life history strategy called year class splitting, where individuals from the same reproductive cohort diverge into two developmental pathways: faster-growing individuals mature and reproduce in their first year, while slower-growing individuals delay maturation until their second year. This species has successfully established introduced populations in eastern North America, including New England, the mid-Atlantic states, and the Pacific Northwest.
Philosciidae
Philosciid Woodlice
Philosciidae is a family of terrestrial isopod crustaceans commonly known as woodlice. The family exhibits a cosmopolitan distribution with strong representation in tropical and subtropical regions, particularly in the Americas, Africa, and Oceania. Species diversity is highest in the Neotropics, with numerous genera and species described from Brazil alone. Several species have adapted to cave environments (troglobitic), including notable examples in the genera Benthana and Benthanoides from iron-ore caves in the Amazon biome. The family is less diverse in the Holarctic realm, where only a few species occur.
Porcellionides
woodlice
Porcellionides is a genus of terrestrial isopods (woodlice) in the family Porcellionidae, characterized by cosmopolitan distribution and ecological adaptability. Species within this genus exhibit notable intraspecific variation in reproductive strategies, with some populations showing seasonal reproduction and others continuous breeding activity. The genus has been extensively studied for its population dynamics, behavioral ecology, and sensitivity to environmental stressors, making it a valuable model organism for soil health assessment.
Porcellionides pruinosus
Powderblues, powder blue woodlouse
Porcellionides pruinosus is a cosmopolitan terrestrial isopod (woodlouse) native to Europe that has achieved global distribution through human-mediated dispersal. The species is detritivorous and occupies diverse terrestrial habitats from agricultural fields to desert margins. It is suspected to represent a cryptic species complex, with ten subspecies currently recognized and significant morphological and reproductive variation documented across populations. The species carries Wolbachia endosymbionts that can induce feminization of males and cytoplasmic incompatibility, affecting population sex ratios. P. pruinosus has become popular in the pet trade, with numerous color morphs selectively bred.
Porcellionides virgatus
Oak Woodlouse
Porcellionides virgatus is a terrestrial isopod commonly known as the Oak Woodlouse. It is a member of the family Porcellionidae and has been documented across North America including the United States and Mexico. The species is frequently recorded in citizen science observations.
Rhyscotus texensis
Texas Woodlouse
Rhyscotus texensis is a terrestrial isopod endemic to Texas, commonly known as the Texas Woodlouse. It belongs to the family Rhyscotidae, a small group of woodlice restricted to the Americas. The species was first described by Richardson in 1905. It is one of the few endemic woodlice species with a well-documented restricted range in North America.
Trachelipus rathkii
Rathke's Woodlouse
Trachelipus rathkii is a medium-sized European woodlouse introduced to North America, where it has established populations across the northern United States and southern Canada. It is distinguished by its tolerance for flooding and poorly drained habitats, often dominating riverside and floodplain communities. The species serves as a documented host for the nematode Caenorhabditis remanei, which associates with it as dauer larvae on its dorsal plates and ventral appendages.
Trichoniscus pygmaeus
Least Pygmy Woodlouse
Trichoniscus pygmaeus is a minute terrestrial isopod commonly known as the Least Pygmy Woodlouse. It is native to Britain and Ireland, with a limited introduced distribution in the United States. The species is among the smallest woodlice in its native range, measuring approximately 2.5 mm in length. Its translucent, pinkish-yellow coloration and diminutive size distinguish it from other European woodlice.
Venezillo microphthalmus
Small-eyed Venezillo Pill Woodlouse
Venezillo microphthalmus is a small terrestrial isopod in the family Armadillidae, endemic to California. The species exhibits the characteristic conglobation (pill-forming) behavior typical of its family, rolling into a defensive ball when disturbed. It is considered rare on the mainland and has documented populations on the Channel Islands. The species is believed to be declining in the San Francisco Bay Area due to competition from introduced woodlouse species.
Venezillo parvus
Little Pill Woodlouse
Venezillo parvus is a small terrestrial isopod commonly known as the Little Pill Woodlouse. It belongs to the family Armadillidae, a group characterized by their ability to conglobate (roll into a complete ball). The species has been documented in both North America and Europe, with its native range presumed to be European and North American populations representing introduced populations. It is a detritivore that contributes to decomposition processes in terrestrial ecosystems.