Monotypic
Guides
Pseudanthoecia
Pseudanthoecia is a genus of moths in the family Noctuidae, established by Smith in 1882. The genus contains a single described species, Pseudanthoecia tumida (Grote, 1880). It is classified within the subfamily Noctuinae and tribe Eriopygini. The genus is known from relatively few observations, with limited published information on its biology.
Pseudhapigia
Pseudhapigia is a monotypic moth genus in the family Notodontidae, established by William Schaus in 1901. The genus contains a single species, Pseudhapigia brunnea, which occurs in North America with its type locality in Guadalajara, Mexico. The species is assigned MONA/Hodges number 8029. The genus is classified within the subfamily Hapigiinae.
Pseudiron
crabwalker mayflies
Pseudiron is a monotypic genus of mayflies containing a single described species, Pseudiron centralis. The genus is notable for its specialized psammophilous (sand-dwelling) ecology and predatory lifestyle, which is uncommon among mayflies. Larvae are active epibenthic predators that inhabit sandy substrates in river systems.
Pseudironidae
crabwalker mayflies
Pseudironidae is a monotypic family of mayflies containing a single genus, Pseudiron, with one described species, Pseudiron centralis. These insects are commonly referred to as crabwalker mayflies, a name reflecting their distinctive locomotion. The family represents a rare example of extreme taxonomic reduction in Ephemeroptera, with its entire diversity contained within one species.
Pseudocnemodus
Pseudocnemodus is a monotypic genus of dirt-colored seed bugs in the family Rhyparochromidae. It was established by Barber in 1911. The genus contains a single described species, P. canadensis. Members of this genus are classified within the tribe Myodochini, a group of ground-dwelling seed bugs.
Pseudogalleria
Pseudogalleria is a genus of tortricid moths established by Émile Ragonot in 1884. The genus contains a single described species, Pseudogalleria inimicella (Zeller, 1872). It is classified within the subfamily Olethreutinae and tribe Grapholitini. The genus has been documented through 437 iNaturalist observations.
Pseudopomala
Pseudopomala is a monotypic genus of slant-faced grasshoppers in the family Acrididae, containing a single described species, P. brachyptera. The genus is classified within the subfamily Gomphocerinae and tribe Mermiriini. It is native to North America, with records from the northeastern and north-central United States.
Pseudorypteryx
Pseudorypteryx is a monotypic genus of cave-dwelling barklice in the family Psyllipsocidae, erected by García-Aldrete in 1984. The genus contains a single described species, Pseudorypteryx mexicana. Members of this genus are troglobitic, meaning they are specialized for life in cave environments.
Pseudoschoenobius
Pseudoschoenobius is a monotypic genus of moths in the family Crambidae, established by Fernald in 1891. The sole species, Pseudoschoenobius opalescalis, is restricted to North America. Adults are small moths with a wingspan of approximately 30 mm.
Pseudosphinx
tetrio sphinx, giant gray sphinx, frangipani hornworm, plumeria caterpillar, Rasta caterpillar
Pseudosphinx is a monotypic moth genus in the family Sphingidae, containing only Pseudosphinx tetrio. The genus is notable for its highly specialized herbivory on toxic Apocynaceae plants and its striking aposematic larval coloration. Adults are large brown sphinx moths with 12.7–14 cm wingspans. The caterpillars are among the largest hornworms in the Americas, exceeding 15 cm in length, and are serious defoliators of ornamental Plumeria species throughout the tropical and subtropical Americas.
Pseudothyatira
tufted thyatirid moth
Pseudothyatira is a monotypic moth genus in the family Drepanidae, established by Augustus Radcliffe Grote in 1864. Its sole species, Pseudothyatira cymatophoroides, ranges across North America from Newfoundland to British Columbia and south to California, Kansas, and North Carolina. Adults fly from June to September with wingspans of 38–44 mm.
Pseudothyris
Pseudothyris is a monotypic moth genus in the family Thyrididae, established by Thiele in 1986. The genus contains a single species, Pseudothyris sepulchralis. It was separated from the genus Thyris based on morphological distinctions.
Pteryngium
silken fungus beetles
Pteryngium is a genus of silken fungus beetles in the family Cryptophagidae, established by Reitter in 1887. The genus contains a single described species, Pteryngium crenatum. These beetles belong to a family commonly associated with fungal associations. The genus has been recorded from northern Europe including Denmark, Norway, and Sweden.
Ptycerata
Ptycerata is a monotypic genus of gelechiid moths described by Ely in 1910. The sole species, Ptycerata busckella, is a small North American moth with distinctive forewing patterning. It is named in honor of August Busck, a prominent American entomologist.
Quadrina
Quadrina is a monotypic moth genus in the family Lasiocampidae, established by Augustus Radcliffe Grote in 1881. The genus contains a single species, Quadrina diazoma, also described by Grote in the same year. This genus is endemic to the southwestern United States, specifically recorded from Arizona and New Mexico. As a member of Lasiocampidae, it belongs to a family commonly known as tent caterpillar moths or lappet moths.
Rhodocantha
Rhodocantha is a monotypic genus of moths in the family Crambidae, established by Munroe in 1961. It contains a single species, Rhodocantha diagonalis, known from limited records in the southwestern United States. The genus belongs to the subfamily Odontiinae, a group of small to medium-sized moths often associated with arid and semi-arid habitats.
Rhyphonemognatha
Rhyphonemognatha is a monotypic genus of blister beetles in the family Meloidae, established by Enns in 1956. The genus contains a single described species, Rhyphonemognatha rufa (LeConte, 1856). These beetles belong to the subfamily Nemognathinae, a group characterized by specialized larval biology involving parasitism or predation on bees and their nests.
Sagenosoma
elsa sphinx moth (sole species)
Sagenosoma is a monotypic genus of sphinx moths in the family Sphingidae, established by Jordan in 1946. The sole species, Sagenosoma elsa (elsa sphinx moth), is restricted to arid regions of the south-western United States and northern Mexico. Adults fly during spring and summer months, with larvae recorded feeding on a specific desert shrub.
Saltonia
Saltonia is a monotypic genus of North American cribellate araneomorph spiders containing the single species Saltonia incerta. The genus was first described in 1942 and has undergone several taxonomic revisions, most recently moved to the family Argyronetidae in 2025. It represents a rare relict lineage restricted to hypersaline desert habitats in southwestern North America.
Sarosesthes
Sarosesthes is a monotypic genus of longhorn beetles (family Cerambycidae) containing a single described species, Sarosesthes fulminans. The genus is classified within the tribe Clytini, a group known for wood-boring larvae and often striking adult coloration. The sole species has been documented in eastern North America, where adults have been collected using fermenting bait traps and ultraviolet light traps.
Scaphinus
Scaphinus is a monotypic genus of long-horned beetles (Cerambycidae) established by LeConte in 1851. The genus contains a single described species, Scaphinus muticus. It belongs to the subfamily Spondylidinae and tribe Spondylidini. The genus is represented by limited observational records.
Schizax
Schizax is a genus of longhorn beetles (Cerambycidae) established by LeConte in 1873. It is monotypic, containing only the single species Schizax senex. The genus is placed in the subfamily Cerambycinae and tribe Trachyderini.
Sclerocona
streaked orange moth
Sclerocona is a monotypic genus of crambid moths in the subfamily Pyraustinae, containing only the species Sclerocona acutella. The genus was established by Meyrick in 1890, though it is treated as a synonym of Calamochrous in some taxonomic databases. The sole species, commonly known as the streaked orange moth, has a broad Palearctic distribution and has been introduced to eastern North America.
Seirarctia
echo moth
Seirarctia is a monotypic moth genus in the family Erebidae, subfamily Arctiinae, established by Alpheus Spring Packard in 1864. The genus contains a single species, Seirarctia echo (the echo moth), described by James Edward Smith in 1797. The species is endemic to the southeastern United States and is known for its caterpillars, which have become locally famous at Stetson University in Florida.
Sericoplaga
Sericoplaga is a monotypic moth genus in the family Crambidae, established by William Warren in 1892. The genus contains a single species, Sericoplaga externalis, also described by Warren in the same year. This genus is endemic to North America.
Shipsa
spring stoneflies
Shipsa is a monotypic genus of spring stoneflies in the family Nemouridae, containing the single species Shipsa rotunda. The genus was described by Ricker in 1952. The sole species has an extensive Nearctic distribution across northern North America, with records from multiple Canadian provinces and US states. Morphological studies indicate little variation in reproductive structures across its wide geographic range.
Shotwellia
Shotwellia is a monotypic genus of band-winged grasshoppers in the family Acrididae. The sole described species, Shotwellia isleta, is a rare North American grasshopper known from limited locations in the Chihuahuan Desert. It has historically been difficult to classify phylogenetically due to its unique morphological characteristics. The genus is currently placed within the Chortophaga genus group based on molecular and morphological evidence.
Simanthedon
Simanthedon is a monotypic genus of bees in the family Apidae, described by Zavortink in 1975. It contains a single described species, Simanthedon linsleyi. The genus belongs to the tribe Eucerini, commonly known as long-horned bees. Very little is known about its biology or ecology.
Snowia
Snowia is a monotypic moth genus in the family Geometridae, established by Berthold Neumoegen in 1884. The genus contains a single species, Snowia montanaria, a North American geometrid moth. This genus is classified within the subfamily Ennominae. The species is assigned MONA/Hodges number 6875.
Somotrichus
Somotrichus is a monotypic genus of ground beetles in the family Carabidae, established by Seidlitz in 1887. It contains a single species, Somotrichus unifasciatus, distributed across the Holarctic region. The genus belongs to the subtribe Somotrichina within the tribe Lebiini.
Spanglerogyrus
Spanglerogyrus is a monotypic genus of whirligig beetles (family Gyrinidae) containing the single species S. albiventris. It represents the only living member of the subfamily Spanglerogyrinae, the earliest diverging extant lineage of gyrinid beetles. The genus was described in 1979 from specimens collected in southern Alabama, making it a rare example of a relictual aquatic beetle lineage in North America.
Sparkia
Sparkia is a monotypic genus of moths in the family Noctuidae, established by Nye in 1975. The sole species, Sparkia immacula, is restricted to Arizona and New Mexico in the southwestern United States. Adults are active from mid-June through late August.
Sphindocis
Sphindocis is a monotypic genus of minute tree-fungus beetles in the family Ciidae. The genus contains a single described species, Sphindocis denticollis, described by Fall in 1917. It is classified within the subfamily Sphindociinae, a small lineage of Ciidae. Very few observations of this genus exist, with only two records documented on iNaturalist.
Spinitibia
Spinitibia is a monotypic genus of moths in the family Autostichidae, established by Lee & Brown in 2010. The genus contains a single species, Spinitibia hodgesi, which is distributed across the southeastern and central United States. The genus name refers to the distinctive spiniform setae on the hind tibia, a diagnostic morphological feature.
Stachyocnemus
Stachyocnemus is a genus of broad-headed bugs in the family Alydidae, established by Stål in 1870. The genus contains a single described species, S. apicalis. Members of Alydidae are characterized by their broad, flattened heads and are commonly known as broad-headed bugs. The genus is part of the subfamily Alydinae within the superfamily Coreoidea.
Stenocolus
Stenocolus is a monotypic genus of beetles in the family Eulichadidae. The sole described species, S. scutellaris, is a forest stream beetle found in western North America. The genus belongs to a small family of aquatic or semi-aquatic beetles associated with running water habitats.
Stenotrachelus
false longhorn beetles
Stenotrachelus is a monotypic genus of false longhorn beetles in the family Stenotrachelidae, containing the single described species Stenotrachelus aeneus. The genus was established by Berthold in 1827. Members of this genus belong to the superfamily Tenebrionoidea and are classified within the subfamily Stenotrachelinae. The family Stenotrachelidae is a small group of beetles sometimes referred to as false longhorn beetles due to their superficial resemblance to cerambycids.
Sternidocinus
Sternidocinus is a monotypic genus of longhorn beetles (Cerambycidae) in the subfamily Lamiinae. The genus contains a single species, Sternidocinus barbarus, described by Van Dyke in 1920. The genus itself was established by Dillon in 1956. The sole species is endemic to California.
Sthenaropsidea
Sthenaropsidea is a genus of plant bugs in the family Miridae, established by Henry & Schuh in 2002. The genus is monotypic, containing a single described species, S. mcateei. As a member of Miridae, it belongs to the largest family of true bugs, though specific biological details remain poorly documented.
Sticthippus
Sticthippus is a genus of band-winged grasshoppers in the family Acrididae, established by Scudder in 1892. The genus contains a single described species, S. californicus. It belongs to the tribe Hippiscini within the subfamily Oedipodinae. The genus is endemic to California.
Strangalepta
Strangalepta is a monotypic genus of longhorn beetles in the family Cerambycidae, established by Casey in 1913. The genus contains only one species, Strangalepta abbreviata, which belongs to the subfamily Lepturinae (flower longhorns). Members of this genus are found in North America.
Strongylocassis
Strongylocassis is a monotypic genus of tortoise beetles established by Hincks in 1950. The genus contains a single species, Strongylocassis atripes. It belongs to the subfamily Cassidinae within the leaf beetle family Chrysomelidae. The genus is rarely encountered, with few documented observations.
Stygoparnus
Comal Springs dryopid beetle (for sole species S. comalensis)
Stygoparnus is a monotypic genus of dryopid beetles containing the single species Stygoparnus comalensis, known as the Comal Springs dryopid beetle. The genus is endemic to central Texas spring systems fed by the Edwards Aquifer. Its sole member is a federally endangered, subterranean-obligate aquatic beetle with vestigial eyes and reduced pigmentation. The genus represents the only known aquatic lineage within the family Dryopidae.
Stygoporus
Stygoporus is a monotypic genus of diving beetles (family Dytiscidae) containing the single species Stygoporus oregonensis. The genus was described in 1994 based on specimens collected from an Oregon bathroom in 1984. No additional specimens were reported until 2014–2016, making this one of the most poorly known beetle genera in North America.
Superstitioniidae
Superstitioniidae is a monotypic family of scorpions containing only the genus Superstitionia and its sole species, Superstitionia donensis. The family is endemic to the southwestern United States and northwestern Mexico, where it inhabits rocky desert environments. It was established by Stahnke in 1940 and represents one of the most taxonomically restricted lineages within Scorpiones.
Synnoma
rabbitbrush webbing moth
Synnoma is a monotypic genus of tortricid moths established by Walsingham in 1879. The sole species, Synnoma lynosyrana (rabbitbrush webbing moth), occurs in western North America. The genus is classified within the tribe Sparganothini of subfamily Tortricinae.
Taniva
Taniva is a monotypic moth genus in the family Tortricidae, established by Carl Heinrich in 1926. It contains a single species, Taniva albolineana (spruce needleminer moth), described by William D. Kearfott in 1907. The genus is characterized by small moths with wingspans around 12 mm. It occurs in northern North America where its larvae mine spruce needles.
Tanygona
Tanygona is a monotypic genus of microlepidopteran moths in the family Cosmopterigidae, containing the single species Tanygona lignicolorella. The genus was established by Braun in 1923. Adults are small with a wingspan of approximately 8 mm.
Tanyrhinus
Tanyrhinus is a monotypic genus of rove beetles (Staphylinidae) containing a single species, Tanyrhinus singularis. It is distinguished from most rove beetles by its elongated elytra that nearly cover the entire abdomen. The genus is restricted to western North America, with records from British Columbia, Canada, and several Pacific coast US states. Its closest relative is the genus Trigonodemus.
Tathorhynchus
Tathorhynchus is a monotypic moth genus in the family Erebidae, established by George Hampson in 1894. It contains a single species, Tathorhynchus exsiccata (the Levant blackneck or double-spotted snout), described by Julius Lederer in 1855. The genus has undergone taxonomic revision, having been briefly transferred to Lygephila in 2003 before being restored to Tathorhynchus in 2005. The species exhibits two recognized subspecies with distinct geographic distributions.