Cryptic
Guides
Formicoxenus hirticornis
Dogwood Guest Ant
Formicoxenus hirticornis is a small myrmicine ant species in the genus Formicoxenus, commonly known as the Dogwood Guest Ant. Species in this genus are specialized social parasites that inhabit nests of larger host ant species, particularly those in the genus Myrmica. The specific epithet 'hirticornis' refers to hairy antennae. This species is rarely encountered and poorly documented in scientific literature.
Furcula cinerea
Gray Furcula Moth
Furcula cinerea, the gray furcula moth, is a notodontid moth species first described by Francis Walker in 1865. It is found across the United States, southern Canada, and the Northwest Territories. Adults have a wingspan of 33–45 mm and are active from spring through late summer, with two generations per year in southern populations and one in northern populations. The species overwinters as pupae.
Gehringiinae
Gehringiinae is a small subfamily of ground beetles (Carabidae) containing approximately 20 described species across two genera: Gehringia and Zuphioides. Members are minute to small beetles, generally less than 3 mm in length, adapted to specialized microhabitats. The subfamily was established to accommodate taxa with distinctive morphological features that separate them from other carabid lineages. They are among the smallest carabid beetles and are rarely encountered due to their cryptic habits.
Gelastocoris oculatus
Big-eyed Toad Bug
Gelastocoris oculatus, commonly known as the big-eyed toad bug, is a riparian predator in the family Gelastocoridae. It inhabits freshwater margins across North and Central America, where its cryptic coloration and hopping locomotion resemble small toads. The species captures smaller insects by leaping onto them and subduing them with piercing-sucking mouthparts. Both adults and nymphs are predatory, with females depositing eggs under rocks or in sand or mud.
Gelastocoris rotundatus
toad bug
Gelastocoris rotundatus is a species of toad bug in the family Gelastocoridae, first described by Champion in 1901. It is one of two Gelastocoris species known from North America, where it occurs in the southwestern United States and southward through Central America. Like other toad bugs, it is a predator associated with aquatic margins.
Glaresis inducta
Glaresis inducta is a small scarab beetle in the family Glaresidae, a group sometimes called "enigmatic scarab beetles" due to their uncertain phylogenetic placement. The species was described by Horn in 1885 and is known from western and central North America, with records spanning from the southwestern United States through the Great Plains and into the upper Midwest. Glaresidae are among the smallest scarab beetles and are rarely encountered due to their cryptic habits and small size.
Glyptocombus saltator
Glyptocombus saltator is a minute true bug in the family Schizopteridae, described by Heidemann in 1906. It belongs to the infraorder Dipsocoromorpha, a group of small predatory or cryptic heteropterans often found in leaf litter and other concealed microhabitats. The species epithet "saltator" suggests jumping ability, a trait common in this group. Very little is known about its specific biology due to its small size and cryptic habits.
Gryllita
Gryllita is a genus of crickets in the family Gryllidae, subfamily Gryllinae, established by Hebard in 1935. The genus contains at least 26 described species, with most described by Otte & Perez-Gelabert in 2009. Species are distributed in the southwestern United States and Mexico, with some Caribbean records. The type species is Gryllita arizonae, commonly known as the Arizona cricket.
Hahnia
comb-tailed spiders, dwarf sheet spiders
Hahnia is the most species-rich genus of the comb-tailed spider family Hahniidae, with approximately 102 valid species distributed worldwide. These spiders are small, cryptic arachnids characterized by their distinctive spinneret arrangement. Most species are under 4 mm in body length as adults. The genus was established by C. L. Koch in 1841 and was formerly classified within Agelenidae until recognized as a distinct family. Species occur across diverse habitats including caves, forest litter, and under bark.
Hahnia cinerea
Ash Hahniid Spider
Hahnia cinerea is a small true spider in the family Hahniidae, commonly known as the Ash Hahniid Spider. It belongs to the subfamily Hahniinae, whose members are characterized by having all six spinnerets arranged in a single transverse row across the back of the abdomen, resembling the teeth of a comb—hence the common name 'comb-tailed spiders.' The species was described by Emerton in 1890 and occurs in North America.
Hallomenus
polypore fungus beetles
Hallomenus is a genus of small beetles in the family Tetratomidae, commonly referred to as polypore fungus beetles. The genus was established by Panzer in 1793 and contains approximately nine described species. Members of this genus are associated with fungi, particularly polypore bracket fungi, which serve as their primary habitat and food source. The genus is distributed across northern regions of Europe and North America.
Heliastus benjamini
Arroyo Grasshopper
Heliastus benjamini, commonly known as the arroyo grasshopper, is a band-winged grasshopper in the family Acrididae. It is native to North America, with confirmed records from Arizona and broader distribution in the southwestern United States. The species inhabits desert environments, particularly canyon and arroyo systems.
Heteraphorura
Heteraphorura is a genus of springtails in the family Onychiuridae, first described by Bagnall in 1948. As a member of the tribe Hymenaphorurini, it belongs to a group of euedaphic (deep soil-dwelling) Collembola characterized by reduced or absent eyes and elongated body forms. The genus has been recorded across multiple continents including Europe, Mediterranean regions, northern Eurasia, and parts of North America.
Hubbardia belkini
Belkin's Short-tailed Whipscorpion
Hubbardia belkini is a species of short-tailed whipscorpion in the family Hubbardiidae. It is one of several species in the genus Hubbardia, which is endemic to the southwestern United States and Mexico. The species was described in 1957 and is known from limited collection records. Short-tailed whipscorpions are small, cryptic arachnids that inhabit moist microhabitats in arid and semi-arid regions.
Hypoponera opacior
Common Crypt Ant, ponerine ant
Hypoponera opacior is a small ponerine ant known for its unusual wing polymorphism in both sexes. Unlike most ant species, it produces both winged and wingless morphs in males and queens, with each morph associated with distinct reproductive behaviors and seasonal timing. The species has been extensively studied for its genetic architecture, which notably lacks the supergene-linked determination found in many other ants with similar reproductive polymorphisms. Males are particularly distinctive, appearing worker-like and wingless in some morphs, with translucent heads that cause frequent misidentification as wasps or braconid parasitoids.
Iralunelus politus
Iralunelus politus is a species of flat bug in the family Aradidae, order Hemiptera. Originally described as Aneurus politus by Thomas Say in 1832, this species has been reclassified into the genus Iralunelus. Aradidae, commonly known as flat bugs or bark bugs, are a family of true bugs characterized by their dorsoventrally flattened bodies adapted for living under bark and in other tight spaces. The family is primarily tropical in distribution, though some species extend into temperate regions of North America.
Isarthrus
Isarthrus is a genus of beetles in the family Eucnemidae (false click beetles), established by LeConte in 1852. Members of this genus are small to medium-sized beetles characterized by their association with decaying wood. The genus is poorly documented in scientific literature, with only eight observations recorded on iNaturalist as of the data cutoff. Isarthrus belongs to a family whose larvae are primarily wood-borers in dead or dying hardwoods.
Jacobsoniidae
Jacobson's beetles
Jacobsoniidae is a small family of minute beetles within the superfamily Staphylinoidea, comprising three extant genera (Derolathrus, Sarothrias, Saphophagus) and approximately 28 described species. Adults and larvae inhabit cryptic microhabitats including leaf litter, rotting wood, fungal fruiting bodies, bat guano, and caves. The family exhibits remarkable morphological stasis since the Cretaceous, with fossil records from Cretaceous amber of Myanmar and France, Eocene Baltic amber, and Holocene copal. Members are among the smallest beetles, measuring 0.7–2.1 mm, and are exceptionally rare in collections.
Larinia
Grass Orb-web Spiders
Larinia is a genus of orb-weaving spiders (family Araneidae) comprising 69 species as of 2026. These medium-sized spiders are characterized by their elongated, straw-coloured bodies and association with grassland habitats. They construct loosely woven orb-webs in vegetation, typically at heights matching surrounding plants. The genus has a cosmopolitan distribution with species documented across multiple continents including Asia, Africa, Europe, the Americas, and Australia.
Lathropus rhabdophloeoides
Lathropus rhabdophloeoides is a species of small, flattened beetle in the family Laemophloeidae, commonly known as lined flat bark beetles. Species in this genus are associated with dead or decaying wood and bark, where they inhabit the concealed spaces beneath bark surfaces. The specific epithet 'rhabdophloeoides' suggests a resemblance to the genus Rhabdophloeus, a related laemophloeid genus. Like other members of Laemophloeidae, this species is likely cryptic in habit and difficult to detect without specialized collecting methods.
Latridiidae
minute brown scavenger beetles, fungus beetles
Latridiidae is a cosmopolitan family of minute beetles containing approximately 1,050 described species in 29 genera, though true diversity is likely much higher. Adults range from 1.2 to 2 mm in length and are uniformly brown to black in coloration. The family is divided into two subfamilies: Latridiinae (glabrous, heavily sculptured dorsal surface, smooth pronotal margin) and Corticariinae (finely pubescent, lightly sculptured, serrate pronotal margin). Both adults and larvae are obligate mycetophages, feeding exclusively on fungal hyphae and spores.
Litaneutria obscura
obscure ground mantis
Litaneutria obscura is a small ground-dwelling mantid native to the desert southwest of North America. Unlike most mantids that employ ambush predation from vegetation, this species is cursorial, actively running down prey on the ground. It is one of two Litaneutria species in the United States, with a more restricted range than its congener L. minor. The species is currently treated as a synonym of L. ocularis by some taxonomic authorities.
Liturgusa
Lichen Mantises, Bark Mantises
Liturgusa is a genus of Neotropical bark mantises comprising more than twenty species. Unlike typical mantises, Liturgusa species are exceptionally fast runners that actively pursue prey rather than ambush it. They inhabit tree trunks and branches, where their flattened bodies and cryptic coloration provide effective camouflage against bark, moss, and lichen. The genus was revised in 2014, revealing substantially greater diversity than previously recognized.
Liturgusa maya
Mayan Lichen Mantis
Liturgusa maya is a Neotropical bark mantis species first described in 1894. It inhabits tree trunks and branches in tropical forests, exhibiting exceptional speed and flattened body morphology adapted for crypsis among bark, moss, and lichen. The species has demonstrated notable geographic expansion through human-mediated introduction, with established non-native populations in Florida (USA) and the Galápagos Islands. In its native range, it has been documented as a frequent inhabitant of cacao agroecosystems in Peru. The species is parthenogenetic in at least some introduced populations.
Loricerinae
Loricerinae is a subfamily of ground beetles in Carabidae, established by Bonelli in 1810. It is monogeneric, containing only the genus Loricera. These beetles are recognized for their distinctive flattened, shield-like body form and association with moist habitats. The subfamily is relatively small in species diversity but has a broad geographic distribution.
Loxosceles
Recluse Spiders, Brown Spiders, Fiddle-backs, Violin Spiders, Reapers
Loxosceles is a genus of venomous spiders in the family Sicariidae, comprising approximately 149 species of cryptic, reclusive, nocturnal arachnids. These spiders are characterized by their six eyes arranged in three pairs, a distinctive violin-shaped marking on the cephalothorax in many species, and cytotoxic venom that can cause necrotic lesions in some bite victims. The genus has a primarily neotropical distribution, with significant diversity in Brazil and the southwestern United States, though some species have been introduced to other regions through human activity.
Loxosceles apachea
Apache Recluse
Loxosceles apachea, the Apache recluse, is a species of recluse spider in the family Sicariidae. It is found in the southwestern United States and Mexico. Like other recluse spiders, it possesses cytotoxic venom that can cause necrotic lesions in rare cases, though bites are uncommon and typically occur only when the spider is trapped against skin. The species is poorly studied compared to the more widespread brown recluse (L. reclusa).
Megaphasma
giant walkingstick
Megaphasma is a genus of giant walkingsticks in the family Diapheromeridae, containing at least two described species. The genus includes Megaphasma denticrus, recognized as the longest insect species in North America, with females reaching 150+ mm in body length. Members of this genus are characterized by their exceptional size, cryptic stick-like appearance, and distinctive morphological features including toothed mesofemora. The genus is primarily distributed in the south-central United States.
Megaphasma denticrus
Giant Walkingstick
Megaphasma denticrus, the giant walkingstick, is the longest insect species native to North America, with females reaching over 150 mm (6+ inches) in body length. This phasmid inhabits wooded areas across the south-central United States and parts of Mexico, where it feeds nocturnally on foliage of trees and shrubs. The species exhibits sexual dimorphism, with females substantially larger than males, and possesses distinctive rows of teeth on the underside of the middle femora that aid in identification. Both sexual and asexual reproduction have been documented, though the resulting ploidy of parthenogenetic offspring remains poorly understood.
Merope tuber
forcepfly, earwigfly
Merope tuber is the sole species in the genus Merope and the only living member of the family Meropeidae in North America. The species occurs in eastern North America from Ontario to Georgia and west to Kansas, with recent records from Florida. Adults are nocturnal and secretive, rarely encountered due to their ground-dwelling habits. The species is notable for the large genital forceps present on male abdomens, which resemble the cerci of earwigs. Immature stages remain unknown, and much of the species' biology is poorly understood.
Metajapyx
Metajapyx is a genus of forcepstails (japygids) in the family Japygidae, first described by Silvestri in 1932. The genus contains more than 30 described species. Members are small, soil-dwelling hexapods characterized by their distinctive pincer-like cerci at the abdomen tip. Like other japygids, they are predatory and primarily inhabit moist soil and leaf litter environments.
Mezira froeschneri
Mezira froeschneri is a species of flat bug in the family Aradidae, described in 1996 from North American specimens. Like other aradids, it has a highly flattened body adapted for living in tight spaces under bark. The species is known from only a handful of observations, reflecting the cryptic habits and difficulty of sampling this group.
Mezira pacifica
Mezira pacifica is a species of flat bug in the family Aradidae, described by Usinger in 1936. The species is found in western North America. Flat bugs (Aradidae) are characterized by their extremely flattened bodies and are typically associated with dead wood or bark habitats. As with other members of this family, M. pacifica likely feeds on fungal hyphae through its piercing-sucking mouthparts.
Mezira vanduzeei
Mezira vanduzeei is a species of flat bug in the family Aradidae, described by Usinger in 1936. The species belongs to a family of true bugs known for their extremely flattened bodies, an adaptation for living in narrow spaces under bark and in decaying wood. Like other aradids, this species likely feeds on fungal hyphae in its concealed microhabitats. Records indicate presence in North America, though detailed biological information remains sparse.
Microcentrum minus
Texas Angle-wing Katydid, Texas Anglewing
Microcentrum minus, commonly known as the Texas Angle-wing Katydid, is the smallest species in the genus Microcentrum. It is a leaf-mimicking katydid found only in extreme south Texas, making it the most geographically restricted member of its genus in the United States. Like other angle-wing katydids, it exhibits cryptic green coloration and produces sound through stridulation.
Microcerberidea
Cerberuses and Pillslaters
Microcerberidea is a suborder of minute isopod crustaceans established by Lang in 1961. Members are among the smallest isopods, measuring less than 2 mm in length. They inhabit interstitial spaces in marine sediments across tropical and subtropical coastal regions.
Microcoryphia
bristletails
Microcoryphia is an order of wingless hexapods commonly known as bristletails, representing one of the two extant orders of apterygote insects. They retain numerous ancestral characteristics that make them significant for understanding early insect evolution, including monocondylic mandibles and the ability to molt throughout their entire life. The group is distinguished by their laterally compressed bodies, large compound eyes, and three long caudal filaments. Approximately 500 species have been described worldwide, with new species continuing to be discovered in diverse habitats including leaf litter, rocky areas, and caves.
Microweisea minuta
Pinpoint Lady Beetle
Microweisea minuta is an exceptionally small lady beetle (family Coccinellidae) native to Texas. Adults measure under 1 mm in length, making it one of the smallest members of its family. The species has a dark, piceous-colored body with a dark brown ventral surface. Like other members of the genus Microweisea, it is associated with scale insects and likely serves as a predator of these pests in its habitat.
Murricia uva
Murricia uva is a species of hersiliid spider described by Foord in 2008. It belongs to the family Hersiliidae, commonly known as tree trunk spiders, recognized for their elongated spinnerets and cryptic bark-dwelling habits. The species is documented from Central Africa, with confirmed records spanning Cameroon to Uganda. Like other hersiliids, it likely exhibits the family's characteristic morphology and behavior, though species-specific details remain limited.
Myriapoda
myriapods
Myriapoda is a subphylum of terrestrial arthropods comprising approximately 13,000–16,000 described species across four extant classes: Chilopoda (centipedes), Diplopoda (millipedes), Pauropoda, and Symphyla. All myriapods are obligate terrestrial, characterized by elongated bodies with numerous segments bearing legs. The group represents one of the earliest arthropod lineages to colonize land, with fossil evidence dating to the Late Silurian–Early Devonian boundary. Myriapods exhibit diverse ecological roles: centipedes are primarily nocturnal predators using venomous forcipules, while millipedes, pauropods, and symphylans function predominantly as detritivores in soil and leaf litter ecosystems.
Myrmechixenini
Myrmechixenini is a tribe of darkling beetles (family Tenebrionidae) established by Jacquelin du Val in 1858. The tribe belongs to the subfamily Diaperinae within the speciose family Tenebrionidae, one of the largest families of beetles. Members of this tribe are characterized by their association with ant colonies, reflecting the etymology of the name (from Greek myrmex, ant, and xenia, hospitality). The tribe contains relatively few described species and is poorly represented in collections, with only 13 observations recorded on iNaturalist.
Myrmecophilus nebrascensis
Nebraska ant cricket
Myrmecophilus nebrascensis, the Nebraska ant cricket, is a species of ant cricket in the family Myrmecophilidae. It is found in North America, with confirmed records from Arizona, Kansas, Nebraska, Nevada, and New Mexico. Like other members of its family, it is an obligate myrmecophile, living in association with ant colonies. The species was described by Lugger in 1898.
Nannaria
Twisted-Claw Millipedes
Nannaria is a genus of small-bodied millipedes in the family Xystodesmidae, commonly known as twisted-claw millipedes. First described by Ralph Chamberlin in 1918, it is now the largest genus in its family with 78 described species following major revisions in 2022. The genus comprises two monophyletic species groups: the widespread minor group found throughout eastern North America, and the wilsoni group restricted to the Appalachian Mountains. Unlike many colorful, flat-backed xystodesmids, Nannaria species are cryptic in appearance and exhibit subterranean behavior that makes them difficult to collect.
Nannaria cingulata
Swamp-Dwelling Twisted-Claw Millipede
Nannaria cingulata is a species of twisted-claw millipede in the family Xystodesmidae, described in 2021 from the Appalachian Mountains of the eastern United States. The species belongs to a genus of small, soil-dwelling millipedes that are cryptic and difficult to collect. Like other members of its genus, it plays a role as a decomposer in forest ecosystems. The specific epithet refers to a banded or girdled appearance.
Nannaria hardeni
Curt Harden's Twisted-Claw Millipede
Nannaria hardeni is a species of twisted-claw millipede described in 2021 from the Appalachian Mountains of the eastern United States. It belongs to the genus Nannaria, a group of forest-dwelling millipedes characterized by males having small, twisted and flattened claws on their anterior legs. The species was named in honor of Curt Harden, a millipede researcher who contributed significantly to the study of Appalachian xystodesmid millipedes. Like other members of its genus, N. hardeni plays a role as a decomposer in forest ecosystems.
Nannaria terricola
Loam-dwelling Twisted-Claw
Nannaria terricola is a flat-backed millipede in the family Xystodesmida, characterized by its loam-dwelling habits and the distinctive twisted, flattened claws on the anterior legs of males. The species is found in the Great Lakes region of the United States. Like other members of the genus Nannaria, it plays a role as a decomposer in forest ecosystems. The species was originally described as Fontaria terricola by Williams & Hefner in 1928 before being transferred to Nannaria.
Nehalennia pallidula
Everglades Sprite
A small damselfly endemic to the southeastern United States, restricted to Florida and Texas. It inhabits swamps and freshwater marshes, where its preference for dense vegetation and diminutive size make it difficult to detect. The species faces significant threats from habitat loss due to water diversion, peat fires, and invasive species.
Neoantistea
dwarf sheet spiders
Neoantistea is a genus of dwarf sheet spiders in the family Hahniidae, established by Willis J. Gertsch in 1934. The genus contains approximately 25 species distributed across North America, Mexico, and parts of Asia. These spiders are characterized by their small size, with most adults under 4 mm in body length. Neoantistea is notable within the Hahniinae for being one of the few genera that constructs webs, unlike related genera such as Hahnia and Antistea.
Neoproxius
Neoproxius is a genus of flat bugs (Hemiptera: Aradidae) established by Usinger and Matsuda in 1959. The genus belongs to the family Aradidae, a group of true bugs characterized by their dorsoventrally flattened bodies adapted for living in confined spaces such as under bark or in decaying wood. As of current records, the genus contains multiple species distributed in specific regional contexts, though detailed biological information remains limited in published literature.
Neotama mexicana
Mexican Two-tailed Spider, Long-spinneret Spider
Neotama mexicana is a species of tree trunk spider in the family Hersiliidae, commonly known as the Mexican two-tailed spider or long-spinneret spider. It is distinguished by its elongated posterior spinnerets, which extend conspicuously beyond the abdomen. The species has been documented from the southern United States through Central America to northern South America, including Peru and Guyana. It is an arboreal species associated with tree trunks and bark habitats.