Subterranean
Guides
Pinodytes
Pinodytes is a genus of small, eyeless beetles in the family Leiodidae, containing at least 40 described species. These beetles are exclusively subterranean, inhabiting soil habitats where they feed on fungal material. The genus was established by Horn in 1880 and belongs to the tribe Catopocerini within the subfamily Catopocerinae. Their eyeless condition reflects complete adaptation to life in darkness.
Pinodytes gibbosus
Pinodytes gibbosus is a small, eyeless soil-dwelling beetle in the family Leiodidae. It inhabits leaf litter in California and feeds on fungi. The species was formally described in 2011, making it a relatively recent addition to the taxonomic literature. Its lack of eyes and subterranean habits reflect adaptations to a life spent primarily in dark, decomposing organic matter.
Pinodytes newelli
Pinodytes newelli is a small, eyeless beetle in the family Leiodidae. It inhabits soil environments and has been observed in Oregon and Washington. The species belongs to a genus specialized for subterranean life, with reduced visual structures.
Pinodytes newtoni
Pinodytes newtoni is an eyeless, soil-dwelling beetle in the family Leiodidae. It is a fungivore, feeding on fungal material in subterranean habitats. The species was described in 2011 and is known from North America.
Pleocoma
rain beetles
Pleocoma is the sole extant genus of Pleocomidae, a family endemic to the Pacific states of North America. These beetles are notable for their extreme subterranean lifestyle, with adults emerging only during fall and winter rains to mate. The genus name derives from Greek words for 'abundant hair,' referring to the dense ventral hair covering. Adults are non-feeding, while larvae are root-feeders with exceptionally long development periods of up to 13 years.
Scarabaeoidearain-beetlessubterraneannon-feeding-adultslong-lived-larvaepheromone-mediated-matingendemicNearcticrelictual-distributionCretaceous-originpest-of-Christmas-treeslamellate-antennaeflightless-femalesrain-triggered-emergenceCalifornia-faunaOregon-faunaWashington-faunaroot-feeding-larvaeextreme-seasonalitylight-attracted-malesPleocomidae
Rain Beetles
Pleocomidae, known as rain beetles, is a family of scarabaeoid beetles found in western North America. The family contains a single extant genus, Pleocoma, with two extinct genera known from the fossil record. Adults emerge in response to rain or snow events, giving the group its common name. The family is considered the sister group to all remaining families of Scarabaeoidea. At least one species, Pleocoma dubitabilis dubitabilis, has been documented as a pest of Christmas trees.
Ponera exotica
Southern Porthole Ant
Ponera exotica is a small ant species in the subfamily Ponerinae, native to North America. Despite its species epithet suggesting foreign origin, it is now interpreted as a native species rather than an introduced exotic. It exhibits a patchy distribution across the conterminous United States and has been collected primarily through subterranean sampling methods.
Porrhomma convexum
Porrhomma convexum is a species of sheetweb spider in the family Linyphiidae, characterized by its small size and association with cave and subterranean habitats. The species was described by Westring in 1851 and has a broad Holarctic distribution spanning North America, Europe, and Asia. Like other members of its genus, it exhibits adaptations to dark environments including reduced pigmentation and eye size. The species constructs sheet webs typical of its family.
Prespelea
Prespelea is a genus of minute rove beetles in the family Staphylinidae, subfamily Pselaphinae. These beetles are troglobitic, meaning they are specialized for life in cave environments. The genus was established by O. Park in 1953 and is classified within the tribe Speleobamini. Members of this genus are eyeless and exhibit morphological adaptations to subterranean habitats.
Prionus geminus
Prionus geminus is a longhorned beetle species in the subfamily Prioninae, described in 2016 from material collected in the Great Plains region of North America. It belongs to the subgenus Homaesthesis, a group of grassland-associated Prionus species whose biology remains poorly documented. The species is part of a genus whose larvae are subterranean root feeders, though specific host associations for P. geminus have not been established.
Proceratium crassicorne
Fat Curltail Ant
Proceratium crassicorne is a rarely encountered ant species described by Emery in 1895. It belongs to the genus Proceratium, a group of specialized predatory ants known for their distinctive elongated petiole and furtive foraging habits. The species epithet 'crassicorne' refers to its notably thick antennae. Like other members of its genus, it is likely a cryptic predator with specific habitat requirements, though detailed biological studies remain limited.
Protaphorura
Protaphorura is a genus of springtails (Collembola) in the family Onychiuridae, established by Absolon in 1901. The genus contains numerous species distributed across the Palearctic region, with particular diversity in southern Siberia and the Far East of Russia. Several species are obligate cave-dwellers (troglobionts), exhibiting specialized adaptations to subterranean environments. The genus is taxonomically well-studied, with identification keys available for over 85 Palearctic species based on morphological characters including pseudocellar formulae, postantennal organ structure, and chaetotaxy.
Pseudanophthalmus cerberus
Pseudanophthalmus cerberus is a species of small ground beetle in the family Carabidae, described by Thomas C. Barr in 1985. It belongs to a genus of troglobitic (cave-dwelling) beetles found in eastern North America. The specific epithet 'cerberus' references the multi-headed guardian of the underworld in Greek mythology, alluding to the species' subterranean habitat.
Pseudanophthalmus cerberus completus
Pseudanophthalmus cerberus completus is a subspecies of small carabid beetle described by Barr in 1985. It belongs to the genus Pseudanophthalmus, a group of troglobitic (cave-dwelling) ground beetles endemic to North America. The subspecies epithet "completus" indicates it represents a fully differentiated form within the P. cerberus species complex. Like other members of this genus, it is likely restricted to subterranean habitats in the eastern United States.
Pseudanophthalmus holsingeri
Holsinger's Cave Beetle
Pseudanophthalmus holsingeri, known as Holsinger's Cave Beetle, is a troglobitic ground beetle endemic to Virginia, United States. The species was described by Thomas C. Barr in 1965. As a member of the genus Pseudanophthalmus, it is adapted to subterranean cave environments.
Pseudanophthalmus nelsoni
Nelson's Cave Beetle
Pseudanophthalmus nelsoni is a small, eyeless ground beetle in the family Carabidae. Described by Barr in 1965, this troglobitic species inhabits cave systems in the United States. Like other members of its genus, it exhibits adaptations to subterranean life including reduced or absent eyes and pale coloration. The species is named in honor of an individual associated with its discovery or study.
Pseudanophthalmus pusio
Ellett Valley Cave Beetle
Pseudanophthalmus pusio is a troglobitic ground beetle endemic to cave systems in the eastern United States. First described by George Henry Horn in 1869, it belongs to a genus of eyeless, pigmentless beetles specialized for subterranean life. The species is known from limited localities in Virginia and represents one of many narrow-range endemics within this genus. Its common name references Ellett Valley in Montgomery County, Virginia, where the type locality is situated.
Pseudanophthalmus robustus
Pseudanophthalmus robustus is a species of small carabid beetle in the tribe Trechini, first described by Valentine in 1931. The genus Pseudanophthalmus comprises eyeless or nearly eyeless ground beetles, many of which are troglobitic (cave-dwelling) species. This species is endemic to the United States, with distribution records limited to North America. Like other members of its genus, it likely inhabits subterranean environments including caves and deep soil habitats.
Pseudanophthalmus tenuis
Blue River cave beetle
Pseudanophthalmus tenuis is a small, eyeless ground beetle endemic to karst cave systems in Indiana, United States. Formerly considered to contain multiple subspecies, these have been elevated to full species status under Pseudanophthalmus stricticollis. The species is part of a genus specialized for subterranean life, with reduced visual structures and elongated appendages adapted to darkness.
Pseudouroctonus reddelli
Texas Cave Scorpion
Pseudouroctonus reddelli, commonly known as the Texas Cave Scorpion, is a troglobitic scorpion species first described in 1972. It belongs to the family Vaejovidae and is endemic to cave systems in Texas. The species exhibits classic cave-adapted traits including reduced pigmentation and elongated appendages. As a specialized cave dweller, it represents an important component of subterranean biodiversity in the karst regions of central Texas.
Psocathropos
Psocathropos is a genus of small, wingless psocids (booklice) in the family Psyllipsocidae. Members of this genus are troglophilic or troglobitic, often found in caves and other subterranean habitats. The genus was established by Ribaga in 1899 and contains species distributed across multiple continents including North America, the Caribbean, and South Asia.
Psyllipsocus
Psyllipsocus is a genus of cave-dwelling barklice comprising more than 50 described species. Members of this genus inhabit dark, humid microhabitats including caves, rock crevices, and similar subterranean environments. The genus was established by Selys-Longchamps in 1872 and represents one of the most species-rich genera within the family Psyllipsocidae.
Pterostichus
Blackclock Ground Beetles
Pterostichus is a large genus of ground beetles (Carabidae) in the subfamily Harpalinae, comprising over 1,200 species with a Holarctic distribution. These beetles are primarily predatory and are commonly found in ground-level habitats, often beneath rocks and debris. The genus exhibits considerable ecological diversity, with species showing varied substrate preferences ranging from sandy soils to subterranean environments.
Ptomaphagus
Ptomaphagus is a genus of small carrion beetles in the family Leiodidae, containing at least 50 described species. Many species are obligately cavernicolous (troglobitic), restricted to cave systems in North America and Eurasia. The genus has been extensively studied as a model system for understanding cave adaptation, speciation, and evolutionary biology. Some species show advanced reproductive isolation, with hybridization experiments demonstrating reduced fecundity and viability between distinct populations.
Pygmarrhopalites
A genus of springtails (Collembola: Symphypleona) in the family Arrhopalitidae. The genus was established by Vargovitsh in 2009. Multiple species have been described, including both epigean and troglobiont (cave-dwelling) forms. Some species exhibit troglomorphies including reduced pigmentation, elongated appendages, and modified foot complex.
Reticulitermes flavipes
Eastern Subterranean Termite
Reticulitermes flavipes, the eastern subterranean termite, is the most common and economically significant termite species in North America. Colonies are large, ranging from 20,000 to 5 million workers, with a primary queen producing 5,000–10,000 eggs annually. The species exhibits complex caste differentiation including workers, soldiers, and multiple reproductive forms. Native to the southeastern United States, it has become invasive in Europe, South America, and other regions through human transport.
Reticulitermes hesperus
western subterranean termite
A subterranean termite species native to the Pacific coast of North America, ranging from British Columbia to Southern California. Recent molecular studies indicate this name may represent a species complex rather than a single biological species, with spring-swarming populations in California now recognized as distinct from fall-winter swarming populations (described as R. rusti). Colonies are eusocial with queens, workers, soldiers, and winged reproductives. This species is a significant structural pest in its native range.
Reticulitermes tibialis
Arid-land Subterranean Termite, Arid Land Subterranean Termite
Reticulitermes tibialis, commonly known as the arid-land subterranean termite, is a native North American termite species adapted to dry environments. It is distinguished from congeneric species primarily by its habitat preferences and genetic characteristics, as morphological differences are minimal. The species occurs across the western and north-central United States, where it serves as an important decomposer of cellulose in arid ecosystems. Unlike some other Reticulitermes species, it causes relatively limited structural damage due to its preference for areas with low human population density.
Rhadine caudata
Rhadine caudata is a brachypterous (flightless) ground beetle in the family Carabidae. It was first described by John Lawrence LeConte in 1863 as Platynus caudatus and later transferred to Rhadine. The species is considered globally Vulnerable by NatureServe, Imperiled in Alabama, and Vulnerable in Virginia. It is widely distributed across the eastern United States but is rare throughout its range, with low dispersal capability.
Rhadine dissecta
Rhadine dissecta is a species of ground beetle in the family Carabidae. It is found in North America. Like other members of the genus Rhadine, it is a cave-associated beetle. The species was described by LeConte in 1863.
Rhadine howdeni
Rhadine howdeni is a species of ground beetle in the family Carabidae, first described by Barr and Lawrence in 1960. It is found in North America, with distribution records from the United States. Like other members of the genus Rhadine, it is likely associated with subterranean or cave habitats, though specific ecological details for this species remain poorly documented. The genus Rhadine includes several federally endangered cave-dwelling species that serve as important indicators of cave ecosystem health.
Rhadine jejuna
Rhadine jejuna is a species of ground beetle in the family Carabidae. It is found in North America. The genus Rhadine includes several cave-dwelling species that are highly specialized for subterranean environments.
Rhadine lanei
Rhadine lanei is a species of ground beetle in the family Carabidae, first described by B.Gray in 1937. It belongs to the genus Rhadine, which contains multiple cave-dwelling species found in Texas. The genus includes several federally endangered species that are ecologically dependent on cave cricket populations.
Rhadine ozarkensis
Rhadine ozarkensis is a species of ground beetle in the family Carabidae, described by Sanderson and Miller in 1941. It is the second species of the genus Rhadine recorded from caves, discovered in the Ozark region. The species possesses morphological adaptations typical of cave-dwelling carabids, including an elongated body and head.
Rhipiceridae
Cicada-Parasite Beetles
Rhipiceridae is a family of beetles specialized as parasitoids of cicada nymphs. Larvae exhibit hypermetamorphosis, with mobile planidial first instars that actively locate and penetrate underground cicada nymphs, developing as endoparasitoids until host death. Adults display pronounced sexual dimorphism: males possess large flabellate antennae with approximately 30,000 sensilla placodea for detecting chemical cues, while females have compact bodies with simple antennae bearing around 100 sensilla. The family comprises seven genera and approximately 100 described species divided into two subfamilies: Rhipicerinae (Australia, New Caledonia, Chile) and Sandalinae (Americas, Africa, Europe, Asia).
Rhopalosiphoninus
Rhopalosiphoninus is a genus of aphids in the family Aphididae. Species in this genus are distributed across Europe, Australia, and North America. The genus includes both above-ground and subterranean-feeding species. At least one species, Rhopalosiphoninus latysiphon, is restricted to potato roots due to climatic intolerance of aerial conditions.
Rhopalosiphoninus latysiphon
bulb-and-potato aphid
Rhopalosiphoninus latysiphon is an aphid species that infests subterranean plant parts, particularly potato roots and bulbs of ornamental plants such as tulip and gladiolus. Its common name reflects its association with both bulb crops and potatoes. The species is distinguished by its preference for cool, damp environments and avoidance of above-ground foliage under normal field conditions. Two subspecies have been described but may be synonyms.
Rhopalosiphum rufiabdominale
rice root aphid, red rice root aphid
Rhopalosiphum rufiabdominale is a globally distributed root-feeding aphid pest with a remarkably broad host range spanning 22 plant families. Native to East Asia, it has established populations across every continent except Antarctica. The species exhibits a heteroecious holocyclic life cycle in its native range, alternating between Prunus species (primary hosts) and herbaceous plant roots (secondary hosts), though asexual reproduction dominates in temperate regions and protected cultivation. Its subterranean habit makes detection difficult and management challenging. The aphid vectors several economically important plant viruses including barley yellow dwarf virus and sugarcane yellow leaf virus, and has emerged as a significant pest of indoor-grown cannabis in North America.
Rogeria
Djirries
Rogeria is a genus of small ants in the subfamily Myrmicinae, distributed primarily in the Neotropical region. The genus contains approximately 40 described species, most of which inhabit leaf litter and soil in tropical forests. Workers are minute to small in size and often exhibit reduced eyes or eyelessness. The genus is distinguished by specialized mandibular structures and reduced pilosity compared to related myrmicine ants.
Scaptocoris castaneus
Scaptocoris castaneus is a burrowing bug species in the family Cydnidae, characterized by fossorial adaptations for subterranean life. The species occurs across North and South America. As a member of the burrowing bug family, it possesses morphological specializations for digging and subterranean existence.
Scaritinae
Pedunculate Ground Beetles
Scaritinae is a large, cosmopolitan subfamily of ground beetles (Carabidae) containing over 2,400 species in more than 140 genera. Members exhibit considerable ecological diversity, with many species adapted to specialized habitats including caves, riverbanks, and deep soil layers. The subfamily includes tribes such as Scaritini, Clivinini, and Salcediini. Several genera show disjunct distributions that have contributed to biogeographic understanding of continental drift and faunal exchange.
Schaefferia
Schaefferia is a genus of springtails (Collembola: Poduromorpha: Hypogastruridae) characterized by troglomorphic adaptations in cave-dwelling species. Recent taxonomic work has described highly specialized subterranean species from Iran and Montenegro that exhibit convergent evolution of eyelessness and elaborated sensory structures. The genus demonstrates significant morphological diversification associated with subterranean habitats.
Sciodrepoides latinotum
Sciodrepoides latinotum is a small carrion beetle in the family Leiodidae, described by Peck & Cook in 2002. It belongs to the subfamily Cholevinae, a group commonly associated with decomposing organic matter and subterranean habitats. The species is known from the eastern and central United States, with records spanning from the Mid-Atlantic to the Great Plains and Gulf Coast.
Serranillus
Serranillus is a genus of small ground beetles in the family Carabidae. The genus was established by Barr in 1995 and contains three described species, all endemic to the United States. These beetles belong to the subtribe Anillina, a group characterized by reduced eyes and elongate bodies adapted to subterranean or soil-dwelling habits. The genus is relatively poorly known, with limited ecological and biological data published.
Siphonophorida
Snout Millipedes
Siphonophorida is an order of millipedes in the subclass Colobognatha containing two families: Siphonophoridae and Siphonorhinidae. These millipedes are characterized by super-elongated, worm-like bodies with up to 190 segments and extreme numbers of legs—up to 750 in Illacme plenipes, the leggiest animal known. They lack eyes and exhibit euanamorphosis, adding segments throughout life even after sexual maturity. The order shows a scattered, disjunct distribution across multiple continents including North America, South America, Africa, Madagascar, India, Southeast Asia, and Australia.
Siphonorhinidae
Siphonorhinidae is a family of millipedes in the order Siphonophorida, characterized by super-elongated trunks with more than 180 diplosegments and leg counts exceeding 710 in some species. The family includes the leggiest animal on Earth, Illacme plenipes, with females possessing up to 750 legs. Members are small, threadlike, slow-moving, unpigmented, and inhabit deep soil microhabitats. The family exhibits a fragmentary, disjunct distribution across California, southern Africa, Madagascar, the Malay Archipelago, Indo-Burma, and now Chile. Siphonorhinidae is represented in the Western Hemisphere solely by the genus Illacme in California and the newly described genus Notorhinus in Chile.
Sitalcina
Sitalcina is a genus of armoured harvestmen (Opiliones) in the family Phalangodidae, established by Nathan Banks in 1911. The genus contains approximately 10 described species, all endemic to western North America, primarily distributed in California and adjacent regions. These harvestmen belong to the suborder Laniatores, a group characterized by relatively short legs and heavily sclerotized body armor. Most species have been described from cave or deep-soil habitats, reflecting a troglomorphic or endogean lifestyle.
Sogdini
Sogdini round fungus beetles
Sogdini is a tribe of small round fungus beetles within the family Leiodidae, comprising approximately 7 genera and at least 20 described species. The tribe was established by Lopatin in 1961. Members are distributed across North and Central America, with species inhabiting northern and mountain forests or sandy habitats. The tribe includes the genera Hydnobius, Kalohydnobius, Macrohydnobius, Platyhydnobius, Sogda, Stereus, and Triarthron.
Speleobama
Speleobama is a genus of rove beetles in the family Staphylinidae, subfamily Pselaphinae. It was described by Orlando Park in 1951 and is the type genus of the tribe Speleobamini. Members of this genus are associated with cave habitats, as indicated by the genus name derived from 'speleo-' (cave) and 'bama' (a suffix used in related genera). The genus contains multiple described species found in North America.
Speleobama vana
Speleobama vana is a species of rove beetle (Staphylinidae: Pselaphinae) described by Orlando Park in 1951. The genus name Speleobama, combining Greek 'speleo' (cave) and 'bama' (step/walk), indicates an association with cave habitats. The species is known from Alabama, USA, and belongs to the tribe Speleobamini within the diverse Pselaphinae subfamily, which contains many small, cryptic beetles often associated with leaf litter, soil, and subterranean environments.