Fossorial
Guides
Aegialia cartwrighti
Aegialia cartwrighti is a small dung beetle in the subfamily Aegialiinae, described by Stebnicka in 1977. It belongs to a genus associated with sandy coastal and desert habitats. The species is known from limited records in the southeastern United States.
Ammopelmatus monahansensis
Ammopelmatus monahansensis is a species of Jerusalem cricket in the family Stenopelmatidae, described by Stidham & Stidham in 2001. The genus Ammopelmatus comprises sand dune endemic species found in the southwestern United States. These flightless orthopterans are characterized by their large size, fossorial habits, and nocturnal activity patterns. A. monahansensis is one of several described species within this genus that are restricted to specific sand dune systems.
Ammopelmatus muwu
Point Conception Jerusalem Cricket
Ammopelmatus muwu is a Jerusalem cricket species in the family Stenopelmatidae. It is endemic to a restricted coastal region of central California, specifically parts of San Luis Obispo and Santa Barbara counties. The species was described in 1981 and is one of several sand dune-associated Ammopelmatus species in western North America. Like other members of its genus, it is nocturnal and fossorial.
Ammopelmatus nigrocapitatus
Black-headed Jerusalem Cricket
Ammopelmatus nigrocapitatus is a species of Jerusalem cricket in the family Stenopelmatidae, originally described by Tinkham & Rentz in 1969. It is one of 12 previously named taxa recognized as valid in a comprehensive 2025 revision of the genus. The species is endemic to parts of Southern California and is characterized by its distinctive black head. Like other Ammopelmatus species, it is a large, flightless orthopteran adapted to arid and semi-arid environments.
Ammophila azteca
Aztec Thread-waisted Wasp
Ammophila azteca is a thread-waisted wasp in the family Sphecidae, native to Canada, Mexico, and the continental United States. It ranges from near sea level to over 6,000 feet in elevation. The species exhibits distinctive nesting behavior involving pebble-mediated burrow closures and progressive provisioning of caterpillar prey for its larvae.
Amnestus pusillus
Amnestus pusillus is a species of burrowing bug in the family Cydnidae, characterized by fossorial (burrowing) habits typical of this group. The species is distributed across the Caribbean, Central America, and North America. As a member of the burrowing bug family, it likely inhabits soil-associated environments, though specific ecological details remain poorly documented in published literature.
Amnestus spinifrons
burrowing bug
Amnestus spinifrons is a species of burrowing bug in the family Cydnidae, first described by Thomas Say in 1825. It belongs to the genus Amnestus, which comprises burrowing bugs that live in soil and are associated with plant roots. The species is known from North America. Burrowing bugs in this family are characterized by fossorial (digging) adaptations and are often found in association with host plants.
Anacrabro
Anacrabro is a genus of square-headed wasps in the family Crabronidae containing approximately 15 described species. Two species occur in North America north of Mexico: A. ocellatus, widespread east of the Rocky Mountains, and A. boerhaviae in the extreme southwestern U.S. and Mexico. The genus is distinguished from related crabronine wasps by its concave abdominal underside and, in A. ocellatus, by its specialized predation on plant bugs (Miridae) rather than flies.
Anacrabro ocellatus
square-headed wasp
Anacrabro ocellatus is a small (6-7 mm) fossorial wasp in the family Crabronidae. Unlike most related genera in tribe Crabronini that hunt flies, this species specializes in capturing plant bugs (family Miridae) to provision its subterranean nest cells. It is widespread east of the Rocky Mountains in North America, with three recognized subspecies. The species is notable for its potential role in biological control of agricultural pests.
Andrena dunningi
Dunning's Miner Bee, Dunning's Miner
Andrena dunningi is a solitary mining bee in the family Andrenidae, native to North America. Like other Andrena species, it is a ground-nesting bee that excavates tunnels in soil to provision with pollen and lay eggs. As a spring-flying bee, it contributes to early-season pollination. The species is one of many Andrena bees that form a significant component of native bee diversity in temperate North American habitats.
Andrena levipes
Andrena levipes is a species of mining bee in the family Andrenidae, described by LaBerge in 1967. It is a solitary, ground-nesting bee native to North America. As a member of the large genus Andrena, it shares the characteristic fossorial nesting behavior typical of mining bees, excavating tunnels in soil to provision with pollen and nectar for its larvae. Specific ecological details for this species remain poorly documented.
Andrena sola
Lonely Mining Bee, lonely miner
Andrena sola is a solitary mining bee in the family Andrenidae, commonly known as the Lonely Mining Bee. It is native to Central America and North America. As a member of the large genus Andrena, it exhibits the fossorial nesting behavior typical of mining bees, constructing underground burrows for reproduction. The specific epithet "sola" (Latin for "alone" or "lonely") reflects its solitary nature rather than social behavior.
Antrodiaetus montanus
Mountain Folding-Door Spider
Antrodiaetus montanus is a mygalomorph spider in the family Antrodiaetidae, commonly known as folding-door spiders. The species constructs silk-lined burrows with hinged, trapdoor-like closures made of silk and soil. It is native to mountainous regions of the western United States. Like other antrodiaetids, it exhibits fossorial behavior and is rarely observed above ground except during dispersal events.
Aphonopelma marxi
Grand Canyon Black Tarantula
Aphonopelma marxi is a North American tarantula species in the family Theraphosidae, commonly known as the Grand Canyon Black Tarantula. It is a medium-sized, dark-colored species belonging to the 'Marxi species group' of mainly black, high-elevation tarantulas. The species was first described in 1891 and has undergone taxonomic revision, with two former species (A. behlei and A. vogelae) now recognized as synonyms. It is widely distributed but difficult to observe due to its fossorial habits.
Aptostichus
Aptostichus is a genus of mygalomorph trapdoor spiders in the family Euctenizidae, described by Eugène Simon in 1891. The genus contains 41 described species distributed primarily in southern California, with some species extending into northern California, Mexico, and the Channel Islands. These spiders are notable for constructing silk-lined burrows with thin wafer-like trapdoors, though unlike some related genera, they do not seal side chambers with additional trapdoors. Several species have been named after prominent figures, reflecting both scientific interest and public engagement in arachnology.
Aptostichus atomarius
San Bernardino hills trapdoor spider
Aptostichus atomarius, the San Bernardino hills trapdoor spider, is a wafer-lid trapdoor spider in the family Euctenizidae. First described by Eugène Simon in 1891, this species is native to the United States. Like other members of its genus, it constructs silk-lined burrows with wafer-like trapdoor lids. The species is part of a diverse genus of trapdoor spiders found primarily in California and surrounding regions.
Aptostichus chemehuevi
Chemehuevi Desert Trapdoor Spider
Aptostichus chemehuevi is a species of trapdoor spider in the family Euctenizidae, described by arachnologist Jason Bond in 2012. It belongs to a genus of mygalomorph spiders known for constructing silk-lined burrows with hinged trapdoor lids. The species epithet references the Chemehuevi people, a Native American group whose traditional territory includes parts of the southwestern United States where this spider occurs. Like other Aptostichus species, it is a fossorial predator with limited dispersal capability.
Aptostichus simus
Southern Coastal Dune Trapdoor Spider
Aptostichus simus is a medium-sized mygalomorph trapdoor spider endemic to coastal sand dune habitats of California and Baja California, Mexico. This fossorial species constructs deep, silk-lined burrows with camouflaged trapdoor lids made of sand and silk, typically situated at the base of native dune vegetation. Recent integrative taxonomic research using genomic data has revealed significant cryptic diversity within this species complex, including the description of a new cryptic species, A. ramirezae, from Moss Landing State Beach. The species exhibits deep genetic divergence dating to 2-3 million years ago despite morphological homogeneity, with populations showing extreme habitat specificity that makes them vulnerable to coastal habitat degradation.
Arenivaga
sand cockroaches, desert cockroaches
Arenivaga is a genus of sand cockroaches in the family Corydiidae, comprising approximately 48 species distributed across the southwestern United States, Florida, and Mexico. These insects are highly adapted to arid environments, inhabiting sandy soils and dunes with moisture content below 1%. The genus exhibits extreme sexual dimorphism, with winged males and wingless, fossorial females that 'swim' through sand. A 2014 revision by Heidi Hopkins added 39 new species to the previously known nine, revealing a remarkable radiation in desert habitats.
Arenivaga floridensis
Florida Sand Cockroach
Arenivaga floridensis is a sexually dimorphic, fossorial sand cockroach endemic to Florida scrub ecosystems. It is the most geographically widespread faunal endemic of Florida scrub, documented from 11 peninsular sand ridges. Genetic analysis reveals three major mitochondrial lineages whose divergence corresponds with late Pliocene peninsula insularization, supporting a western origin hypothesis with colonization during the Pliocene or earlier. The species exhibits extreme sexual dimorphism: males possess fully developed wings and engage in low, erratic flight at dusk, while females are completely wingless and remain entirely fossorial throughout life. Its distribution is restricted to friable, sandy soils beneath light leaf litter of sand live oaks (Quercus geminata).
Arenivaga hopkinsorum
desert cockroach, sand cockroach
Arenivaga hopkinsorum is a species of desert cockroach in the family Corydiidae, described by Heidi Hopkins in 2014 as part of a major revision of the genus Arenivaga. Like other Arenivaga species, it exhibits dramatic sexual dimorphism, with females appearing wingless and males possessing fully developed wings. The species inhabits arid environments in the southwestern United States and Mexico, where it contributes to decomposition despite limited plant matter. The specific epithet honors the Hopkins family, particularly referencing the author's father and brother.
Arenivaga investigata
desert cockroach
Arenivaga investigata, the desert cockroach, is a species in the family Corydiidae endemic to the Colorado Desert of California. It is notable for its ability to absorb water vapor from unsaturated air above 82.5% relative humidity, a physiological adaptation that allows survival in one of the most arid environments on Earth. The species exhibits extreme sexual dimorphism, with wingless females and fully winged males. It inhabits sand dunes and is primarily found in subsurface microhabitats where temperature and moisture conditions remain favorable.
Arenophilus
Arenophilus is a genus of soil-dwelling centipedes in the family Geophilidae, order Geophilomorpha. These elongated, multi-legged arthropods inhabit terrestrial environments. The genus was established by Chamberlin in 1912. Members possess the characteristic features of geophilid centipedes, including numerous leg pairs and a fossorial lifestyle adapted to burrowing in soil and leaf litter.
Aspidoglossa
Aspidoglossa is a genus of ground beetles (family Carabidae) established by Putzeys in 1846. The genus comprises approximately 26 described species distributed primarily in the Neotropics, with a single species, Aspidoglossa subangulata, extending into the southern United States. These beetles belong to the subtribe Ardistomina within the tribe Clivinini, a group characterized by fossorial (burrowing) adaptations. The genus has been documented through 629 iNaturalist observations, indicating moderate levels of citizen science engagement.
Astatinae
Astatina wasps
Astatinae is a cosmopolitan subfamily of solitary wasps in the family Crabronidae, comprising approximately 14 species in North America and additional species across Europe and Asia. The subfamily includes two primary genera: Astata and Dryudella. Males are readily distinguished by their holoptic eyes—enormous compound eyes that meet at the top of the head—and exceptionally broad hind wings that enable rapid flight. Females are fossorial, constructing multi-celled nest burrows in soil or sand and provisioning them with paralyzed true bugs (Hemiptera) as food for their larvae.
Atypus
Purse-web Spider, Purseweb Spider
Atypus is a genus of mygalomorph spiders commonly known as purse-web spiders, first described by Latreille in 1804. These spiders construct distinctive silk tubes (purse-webs) that extend from underground burrows vertically along tree bases, fences, or other surfaces. The genus occurs across Eurasia and northern Africa, with 38 described species as of 2025. Atypus species are perennial, with females living 8–10 years, and conduct nearly all life activities—including predation, mating, and egg-laying—within their sealed webs. One Asian species, A. karschi, has been introduced and established in southeastern Pennsylvania, USA.
Bibio articulatus
red-legged march fly
Bibio articulatus is a species of march fly in the family Bibionidae, commonly known as the red-legged march fly. It is distinguished by its dark exoskeleton ranging from black to deep red and its conspicuous red or orange legs. The species exhibits pronounced sexual dimorphism, particularly in eye size and body proportions. It is most active during spring months and is found primarily in the eastern United States.
Bibio rufipes
March fly
Bibio rufipes is a species of march fly in the family Bibionidae. Adults emerge in spring, with males forming conspicuous swarms that blanket ground and low vegetation. Females possess fossorial adaptations including stout, downcurved spurs on the fore tibiae used to excavate soil for egg-laying. The species occurs across northern Europe including Norway and Sweden.
Bicyrtes capnopterus
Bicyrtes capnopterus is a species of sand wasp in the family Crabronidae. It occurs in Central America and North America. Like other members of the genus Bicyrtes, females are fossorial, excavating burrows in soil to provision with prey for their larval offspring. The species is part of a group of wasps known for preying on true bugs, contributing to natural control of pest populations.
Bicyrtes fodiens
Bicyrtes fodiens is a solitary sand wasp in the family Crabronidae, native to North and Middle America. Like other members of its genus, it is a fossorial species that excavates burrows in sandy or coarse soil to provision with paralyzed true bugs for its larval offspring. The species is part of a guild of beneficial predatory wasps that help control pest insect populations, including stink bugs. Adults are nectar-feeders and can often be observed visiting flowers.
Bicyrtes insidiatrix
Bicyrtes insidiatrix is a species of sand wasp in the family Crabronidae. It is found in North America. Like other members of the genus Bicyrtes, it is a solitary, fossorial wasp that nests in sandy or coarse soils. The species is part of a group of wasps known for preying on true bugs (Hemiptera), though specific prey records for this species are not well documented in the available literature.
Bicyrtes quadrifasciatus
Four-banded Stink Bug Wasp, four-banded stink bug hunter wasp
Bicyrtes quadrifasciatus is a sand wasp native to North America, east of the Rocky Mountains. Females construct solitary burrows in sandy soil to provision with paralyzed true bugs, primarily stink bugs (Pentatomidae), as food for their larvae. The species has gained attention for its role as a native biological control agent of the invasive Brown Marmorated Stink Bug (Halyomorpha halys). Adults are nectar-feeders and can be readily observed at flowers.
Bicyrtes variegatus
sand wasp
Bicyrtes variegatus is a sand wasp species in the family Crabronidae, distributed across Central and South America with established populations in the Galápagos Islands. The species exhibits notable behavioral flexibility, having been documented in diverse vegetation zones from littoral to humid habitats and interacting with both native and introduced flora. As a member of the Bembicinae, it shares the subfamily's characteristic fossorial nesting habits and prey specialization on true bugs, though specific ecological details remain incompletely documented across its broad range.
Bicyrtes ventralis
Bicyrtes ventralis is a sand wasp in the family Crabronidae, distributed across Central America and North America. Like other members of the genus Bicyrtes, it is a solitary, fossorial wasp that nests in soil. Females provision underground burrows with paralyzed true bugs as food for their larval offspring. The species is one of approximately eight North American species in the genus Bicyrtes.
Bicyrtes viduatus
Bicyrtes viduatus is a sand wasp in the family Crabronidae, found in Central America. It is characterized by pale yellow coloration and lacks the distinctive thoracic 'smiley face' pattern present in related yellow-colored species B. capnopterus and B. ventralis. The submarginal cell of the wing is clouded while the wings remain largely clear. As a member of the genus Bicyrtes, it shares the family's general biology as a solitary, fossorial wasp that preys on true bugs.
Bolboceratinae
earth-boring scarab beetles
Bolboceratinae is a subfamily of earth-boring scarab beetles within Geotrupidae, containing approximately 8 genera and at least 40 described species. The group exhibits a disjunct global distribution with centers of diversity in Australia, South America, southern Africa, and parts of Eurasia. Some authorities recognize Bolboceratinae as the family Bolboceratidae. Members are characterized by fossorial adaptations and diverse reproductive strategies including egg gigantism in some lineages.
Bolbocerosoma confusum
Bolbocerosoma confusum is an earth-boring scarab beetle in the family Geotrupidae, described by Brown in 1928. It is native to North America, with documented records from Arkansas, Illinois, Iowa, Louisiana, Missouri, Oklahoma, and Texas. As a member of the bolboceratine geotrupids, it exhibits the family's characteristic fossorial adaptations for burrowing in soil.
Brachycistidinae
Brachycistidinae is a subfamily of flower wasps (Tiphiidae) containing 10 genera and 85 species endemic to the Nearctic region. These wasps exhibit extreme sexual dimorphism: females are wingless and ant-like, living primarily underground, while males are winged and nocturnal. The subfamily has historically suffered from "dual taxonomy," where sexes were described as separate species due to their dissimilar appearance. Taxonomic resolution remains challenging due to structural similarities among species and lack of distinctive coloration.
Bradycinetulus
Bradycinetulus is a genus of earth-boring scarab beetles in the family Bolboceratidae, established by Cockerell in 1906. The genus contains at least three described species distributed in the Nearctic region. These beetles are robust, fossorial insects adapted for burrowing in soil. Field observations indicate adults are attracted to lights at night and have been collected from sand dune habitats and pack rat runs.
Bradycinetulus ferrugineus
Bradycinetulus ferrugineus is a species of earth-boring scarab beetle in the family Geotrupidae. It occurs in the southeastern United States, with records from Florida, Mississippi, North Carolina, and South Carolina. The species is associated with rodent burrows, particularly pack rat runs, where adults and larvae have been collected.
Bradycinetulus fossatus
fossate bolboceratine, fossate earth-boring dung beetle
Bradycinetulus fossatus is a large, robust bolboceratine geotrupid beetle found in sand dune and sandy grassland habitats of the south-central United States. The species is characterized by its chunky body form and fossorial (burrowing) adaptations typical of the subfamily. It is attracted to lights at night and has been documented in Oklahoma, New Mexico, and Texas. The species is part of a small genus of North American bolboceratines that are poorly studied relative to their ecological role in sandy ecosystems.
Bradycinetulus rex
earth-boring scarab beetle
Bradycinetulus rex is an earth-boring scarab beetle described by Cartwright in 1953. It belongs to the family Geotrupidae, a group commonly known as earth-boring dung beetles for their habit of digging burrows in soil. The species is known from the Nearctic region, with records from Texas. Like other members of its genus, it likely exhibits the fossorial (burrowing) habits characteristic of the family.
Chanbria
camel spiders, sun spiders
Chanbria is a genus of camel spiders (order Solifugae) established by Martin H. Muma in 1951. It comprises four recognized species endemic to the Sonoran Desert region of the southwestern United States and northwestern Mexico. Adults measure 20–30 mm and possess distinctive fan-shaped malleoli on the hind legs containing approximately 72,000 sensory neurons each. Juveniles exhibit specialized fossorial hunting behavior, using tactile and chemical cues to locate prey beneath sand.
Clivina
A ground beetle in the genus Clivina, family Carabidae, from Stanislaus County, California. Members of this genus are small, fossorial carabid beetles adapted to burrowing in soil. The specific identity of this specimen is not determined beyond genus level.
Clivina californica
Clivina californica is a species of ground beetle in the subfamily Scaritinae, described by Van Dyke in 1925. The genus Clivina comprises small, fossorial ground beetles characterized by their compact, cylindrical body form adapted for burrowing in soil. Species in this genus are morphologically conservative and often difficult to distinguish without detailed examination.
Clivina fossor
Digger Slope-rumped Beetle
Clivina fossor is a ground beetle in the subfamily Scaritinae, described by Linnaeus in 1758. It is the largest species in its subfamily, characterized by fossorial (digging) adaptations including broad tarsal segments on the forelegs. The species exhibits a widespread Palaearctic distribution with introduced populations in North America, and shows flexible habitat use across grasslands, wetlands, woodlands, and agricultural areas. Adults are nocturnal and subterranean by day, while larvae live entirely underground.
Clivina fossor fossor
Clivina fossor fossor is a subspecies of ground beetle in the family Carabidae, first described by Linnaeus in 1758. It belongs to a genus characterized by fossorial (digging) adaptations, with females possessing modified forelegs for excavating burrows in soil. The subspecies has been recorded across parts of North America and Europe, though detailed biological studies remain limited.
Clivina pallida
Pale Slope-rumped Beetle
Clivina pallida is a species of ground beetle in the subfamily Scaritinae, described by Thomas Say in 1823. It belongs to the genus Clivina, a group of small, fossorial carabid beetles commonly known as ant-like stone beetles or slope-rumped beetles. The species epithet "pallida" refers to its pale coloration. Very little specific biological information is documented for this particular species.
Clivina punctigera
Clivina punctigera is a species of ground beetle in the subfamily Scaritinae, described by John Lawrence LeConte in 1857. The genus Clivina comprises small, fossorial ground beetles characterized by their compact bodies and fossorial (burrowing) adaptations. Like other members of Scaritinae, this species likely exhibits morphological traits associated with subterranean or soil-dwelling habits, though specific details for C. punctigera remain poorly documented.
Clivina rufa
Clivina rufa is a ground beetle species in the subfamily Scaritinae, described by John Lawrence LeConte in 1857. The genus Clivina comprises small, fossorial ground beetles commonly known as ant-loving beetles or seedcorn beetles. Members of this genus are typically found in soil and leaf litter habitats. The species epithet 'rufa' refers to reddish coloration.