Monotypic-genus
Guides
Rhynchus apiculatus
hidden snout weevil
Rhynchus apiculatus is a species of hidden snout weevil in the family Curculionidae, described by Kissinger in 1964. It is the sole member of the monotypic genus Rhynchus. The genus name derives from the Greek ῥύγχος (rhynchos), meaning snout. The species has been recorded from North America.
Rhyzopertha
Grain-borers
Rhyzopertha is a monotypic genus of beetles in the family Bostrichidae (false powderpost beetles). The sole species, Rhyzopertha dominica, is commonly known as the lesser grain borer and is a major worldwide pest of stored cereal grains and peanuts. The genus is characterized by its cylindrical body form and association with dry stored products.
Rifseria
Rifseria is a monotypic genus of gelechiid moths established by Hodges in 1966. The genus contains a single species, Rifseria fuscotaeniaella, distributed across western North America. The larvae are leaf miners specializing on plants in the Asteraceae family.
Rifseria fuscotaeniaella
Rifseria fuscotaeniaella is a small moth and the sole species in the monotypic genus Rifseria, family Gelechiidae. It is endemic to western North America, ranging from the Canadian prairies through the Rocky Mountain region to the Pacific coast. The species was originally described as Gelechia fuscotaeniaella by Chambers in 1878. It is associated with arid and semi-arid habitats including sagebrush steppe and dry open woodlands.
Rilettius socius
Rilettius socius is a small beetle species in the family Anthicidae, described by Abdullah in 1964. Members of this family are commonly known as ant-like flower beetles due to their convergent resemblance to ants. The genus Rilettius is monotypic, containing only this species. Published information on its biology and ecology is extremely limited.
Rileyonymus
minute seed weevils
Rileyonymus is a genus of minute seed weevils in the family Curculionidae. It contains a single described species, R. relictus. The genus was established by W.G. Dietz in 1896.
Ruacodes tela
Ruacodes tela is a moth species in the family Noctuidae, the only member of the monotypic genus Ruacodes. It was first described by John Bernhardt Smith in 1900 and is found in Arizona, United States. The genus was erected by George Hampson in 1908.
Rustleria
Rustleria is a monotypic genus of beetles in the family Teredidae, established by Stephan in 1989. The genus contains a single described species, R. obscura. Teredidae, formerly treated as a subfamily of Tenebrionidae, comprises small to medium-sized beetles often associated with dead wood and fungal habitats.
Sagenosoma elsa
Elsa Sphinx, elsa sphinx moth
Sagenosoma elsa is a monotypic species of sphinx moth in the family Sphingidae, known as the Elsa Sphinx. It is the sole member of its genus and occurs in the southwestern United States and northern Mexico. The species was first described by Strecker in 1878 under the name Sphinx elsa. Like other sphingid moths, adults are likely capable of sustained hovering flight and rapid, agile movement.
Sagotylus
Sagotylus is a genus of leaf-footed bugs in the family Coreidae, established by Mayr in 1865. The genus contains a single described species, S. confluens. Members of this genus are true bugs (Hemiptera) within the suborder Heteroptera.
Saltonia incerta
Rare sheet-web-weaving spider, sole representative of monotypic genus Saltonia. Restricted to salt crusts of intermittent or dry lakes, streams, and rivers in desert southwestern North America. Previously presumed extinct following 1905 flooding of type locality at Salton Sea, but rediscovered in 1990s at multiple sites. Genetic analyses reveal significant population structure with two major clades (New Mexico versus California-northern Baja California) and minimal gene flow among isolated populations in fragmented desert salt flat habitats.
Sarasota plumigerella
Sarasota plumigerella is a species of moth in the family Pyralidae, subfamily Phycitinae, first described by George D. Hulst in 1900. The genus Sarasota is monotypic, containing only this single species. Like other members of the Phycitinae, it is presumed to be a small moth with larvae that likely feed on plant material, though specific life history details remain poorly documented. The species epithet and genus name reference Sarasota, Florida, suggesting a type locality or association with this region.
Schizax senex
Schizax senex is a species of longhorn beetle (Cerambycidae) and the sole member of the monotypic genus Schizax. The species was described by John Lawrence LeConte in 1873. It belongs to the tribe Trachyderini within the subfamily Cerambycinae. Based on distribution records, it occurs in the United States.
Sebaga
Sebaga is a genus of ant-loving beetles in the family Staphylinidae, subfamily Pselaphinae, tribe Jubini. It was established by Raffray in 1891. The genus contains a single described species, Sebaga ocampi. These beetles are myrmecophilous, meaning they live in association with ants.
Seirarctia echo
Echo Moth
Seirarctia echo, the Echo Moth, is a monotypic tiger moth species in the family Erebidae. It is endemic to the southeastern United States, where it inhabits thickets, scrublands, and open areas. The species was first described by James Edward Smith in 1797 based on specimens from Georgia.
Selenacentrus
Selenacentrus is a monotypic genus of treehoppers in the family Membracidae, subfamily Centrotinae, described by Morris and Dietrich in 2016. The genus contains a single species, Selenacentrus wallacei, found in Texas and northern Mexico. The genus was named in honor of Selena Quintanilla-Pérez, the "Queen of Tejano Music." Selenacentrus lacks diagnostic features of currently recognized tribes within Centrotinae, including specific male genital capsule structures and femoral setae patterns, and does not fit into existing tribal classifications based on wing venation.
Selenacentrus wallacei
Selenacentrus wallacei is a treehopper species in the family Membracidae, described by Morris and Dietrich in 2016. It represents the sole species of the monotypic genus Selenacentrus. The species was discovered among mislabeled specimens in multiple museum collections and is known from Texas and northern Mexico. Its taxonomic placement required the establishment of a new genus due to unique morphological characteristics that do not align with any recognized tribes within the subfamily Centrotinae.
Selicanis
Selicanis is a genus of moths in the family Noctuidae, established by Smith in 1900. The genus is monotypic, containing only Selicanis cinereola, described from the same publication. It is placed within the subfamily Noctuinae, one of the largest subfamilies of owlet moths. The genus is poorly known, with minimal published information beyond its original description.
Sericoplaga externalis
Falcate Sericoplaga
Sericoplaga externalis is a moth species in the family Crambidae and the sole member of its genus. It is found in eastern and central North America, ranging from Maryland to Illinois and south to Florida and Texas. The species is commonly known as the Falcate Sericoplaga. It has been documented in 1,479 iNaturalist observations, indicating it is moderately well-recorded but not extensively studied.
Shotwellia isleta
Shotwellia isleta is a rare, monotypic band-winged grasshopper described by Gurney in 1940. Molecular phylogenetic analysis places it as sister to other genera within the Chortophaga genus group of Oedipodinae. The species is a habitat specialist restricted to isolated locations in the Chihuahuan Desert.
Souessa spinifera
Souessa spinifera is a sheet web weaving spider and the sole member of the monotypic genus Souessa. First described by O. Pickard-Cambridge in 1874 and later placed in its current genus by Crosby & Bishop in 1936, this small arachnid belongs to the dwarf spider family Linyphiidae. It has been documented only from the United States, with records from multiple states.
Soulgas
Soulgas is a monotypic genus of sheet web spiders (family Linyphiidae) endemic to the United States. It was established in 1936 by C. R. Crosby and S. C. Bishop and contains a single species, Soulgas corticarius. The genus is known from very few observations and remains poorly documented.
Spanglerogyrus albiventris
Spanglerogyrus albiventris is a whirligig beetle in the family Gyrinidae, described in 1979 from specimens collected in southern Alabama. It is the sole extant species in its genus and the only living member of the subfamily Spanglerogyrinae, which represents the earliest diverging lineage among extant gyrinids. The subfamily also includes the extinct genus Angarogyrus from the Jurassic and Cretaceous of Asia.
Sparkia immacula
Sparkia immacula is a noctuid moth and the sole member of its genus. It is found in the southwestern United States, specifically in Arizona and New Mexico. The genus was established by Augustus Radcliffe Grote in 1883. Very little biological information is available for this species.
Spathilepia
Falcate Skipper
Spathilepia is a monotypic genus of skippers in the family Hesperiidae, subfamily Eudaminae. The sole species, Spathilepia clonius, is known as the Falcate Skipper. The genus was established by Arthur Gardiner Butler in 1870. It is distributed from the southern United States through Central America and into South America.
Spathilepia clonius
Falcate Skipper
Spathilepia clonius, commonly known as the Falcate Skipper, is the sole species in the monotypic genus Spathilepia within the skipper family Hesperiidae. This butterfly ranges from the southern United States through Central America and into South America as far as Argentina. It is a member of the subfamily Eudaminae, a group characterized by their robust bodies and rapid, darting flight patterns. The species has been documented across diverse tropical and subtropical habitats.
Sperchopsis
Sperchopsis is a genus of water scavenger beetles in the family Hydrophilidae. The genus was established by LeConte in 1861. It contains a single described species, Sperchopsis tessellata.
Steffanolampus
Steffanolampus is a monotypic genus of chalcidoid wasps established by Peck in 1974 to accommodate Perilampus salicetum Steffan. The single species has a Nearctic distribution, with records from eastern Canada and the United States extending from Quebec to Maryland and Michigan, plus an isolated western population in Washington State. It is associated with anobiid beetles, though the precise nature of this relationship remains unspecified.
Stenelaphus
Stenelaphus is a monotypic genus of longhorn beetles (Cerambycidae) in the tribe Elaphidiini, containing a single species, Stenelaphus alienus. The genus was established by Linsley in 1936. Based on collection records from Arizona, adults have been observed at ultraviolet lights in montane canyon habitats during summer months, suggesting nocturnal activity patterns typical of many cerambycid beetles.
Stenobaris
Stenobaris is a genus of flower weevils in the family Curculionidae, established by Martin L. Linell in 1897. The genus is monotypic, containing only one described species: Stenobaris avicenniae. As a member of Curculionidae, it possesses the characteristic elongated snout (rostrum) typical of weevils. The genus is poorly documented in scientific literature, with limited biological or ecological information available.
Sternidocinus barbarus
Sternidocinus barbarus is a longhorn beetle (Cerambycidae) and the sole species in its genus. It was described by Van Dyke in 1920 based on specimens from western North America. The species belongs to the subfamily Lamiinae, tribe Acanthocinini, a group characterized by often cryptic coloration and nocturnal habits. Its monotypic genus status makes it taxonomically distinctive within the diverse cerambycid fauna of North America.
Strangalepta abbreviata
Strangalepta Flower Longhorn Beetle
Strangalepta abbreviata is a longhorn beetle and the sole member of its genus. It belongs to the flower longhorn subfamily Lepturinae, a group known for visiting flowers as adults. The species is moderately well-documented across eastern and central North America.
Striacosta
western bean cutworm (for sole species S. albicosta)
Striacosta is a monotypic genus of moths in the family Noctuidae, established by Lafontaine in 2004. The sole species, Striacosta albicosta (western bean cutworm), is an agricultural pest native to North America. The species underwent significant range expansion from the western Great Plains to eastern North America beginning in 1999. Larvae are serious pests of corn and dry bean crops, with documented resistance to Cry1F Bt protein.
Superstitionia
Superstitionia is a monotypic genus of scorpions containing the single species S. donensis. It is the only genus in the family Superstitioniidae. Unlike other members of its family, which are cave-adapted and lack pigmentation and lateral eyes, S. donensis is darkly pigmented and possesses lateral eyes. The genus was established in 1940 based on specimens from the Superstition Mountains of Arizona.
Synaphaeta guexi
Spotted Tree Borer
Synaphaeta guexi is a longhorn beetle and the sole species in its genus. It inhabits the Pacific coastal region of North America, from British Columbia to California. The species develops in hardwood trees and is known by the common name Spotted Tree Borer. It was described by John Lawrence LeConte in 1852.
Synnoma lynosyrana
rabbitbrush webbing moth
Synnoma lynosyrana, the rabbitbrush webbing moth, is the sole species in the monotypic genus Synnoma. It belongs to the subfamily Tortricinae of the family Tortricidae. The species is found in western North America, with records from Arizona. Its common name suggests an association with rabbitbrush (Ericameria/Chrysothamnus species).
Tachopteryx
gray petaltail, Thorey's grayback
Tachopteryx is a monotypic genus of dragonflies in the family Petaluridae, containing only Tachopteryx thoreyi. This species is notable for having a non-burrowing larval stage, unlike most other petalurids. Adults are medium-sized dragonflies with distinctive gray and black coloration.
Taniva albolineana
Spruce Needleminer Moth
Taniva albolineana is a monotypic tortricid moth endemic to North America, commonly known as the spruce needleminer moth. The species is specialized on spruce (Picea spp.) as its host plant, with larvae mining within needles. It is the sole member of the genus Taniva. The moth is primarily documented from the Canadian prairie provinces and adjacent regions.
Tapinesthis
Ivy parchment spider
Tapinesthis is a monotypic genus of goblin spiders (family Oonopidae) containing only Tapinesthis inermis, commonly known as the ivy parchment spider. The genus is characterized by its spineless legs, steeply sloping carapace with a dark net-like pattern, and soft body structure. Originally native to Europe, the species has been introduced to North America and shows synanthropic tendencies, frequently inhabiting human dwellings alongside natural habitats. The genus name reflects its distinctive morphological features within the diverse goblin spider family.
Tapinesthis inermis
Tapinesthis inermis is a minute spider species in the family Oonopidae (dwarf goblin spiders). It is the sole member of its genus, which was established by Simon in 1914 based on specimens originally described as Oonops inermis in 1882. The species is native to Europe and has been introduced to North America (Canada and USA).
Tehama
western lawn moth (for sole species Tehama bonifatella)
Tehama is a monotypic genus of moths in the family Crambidae, established by George D. Hulst in 1888. The genus contains a single species, Tehama bonifatella, commonly known as the western lawn moth. This small moth is distributed across northern North America, including Greenland, Canada, and the western United States, where it inhabits grassland ecosystems. The larvae feed on grasses, making it one of the few crambid moths associated with lawn and turf habitats.
Tehama bonifatella
Western Lawn Moth
Tehama bonifatella, the western lawn moth, is a small grass moth in the family Crambidae. It is the sole species in the monotypic genus Tehama. The species is associated with grassland habitats and has been recorded across western and northern North America, including Greenland.
Tethida
Tethida is a genus of sawflies in the family Tenthredinidae, established by Ross in 1937. The genus contains at least one described species, Tethida barda. As a member of the suborder Symphyta, these insects lack the constricted 'wasp waist' characteristic of many other Hymenoptera.
Thricolema
Thricolema is a monotypic genus of leaf beetles in the subfamily Synetinae, containing only Thricolema anomala. Adults are associated with Calocedrus decurrens (incense-cedar) and have been recorded from California and Oregon. The genus is distinguished from the similar Syneta by tarsal claw morphology in females.
Thrinaphe hargeri
Thrinaphe hargeri is a millipede species and the sole member of the genus Thrinaphe, described by Rowland M. Shelley in 1993. The species is endemic to the Cascade Mountains region along the Washington-Oregon border and the Willamette Valley in the Pacific Northwest of the United States. It belongs to the family Xystodesmidae, a diverse group of flat-backed millipedes.
Thurberiphaga diffusa
Thurberiphaga diffusa is the sole species in the monotypic moth genus Thurberiphaga, placed in the family Noctuidae (subfamily Acontiinae, tribe Chamaecleini). The genus was erected by Harrison Gray Dyar Jr. in 1920, with the species originally described by William Barnes in 1904. This noctuid moth is known from North America, though specific details about its biology and host associations remain poorly documented in available literature.
Thylodrias contractus
Odd Beetle, tissue paper beetle
Thylodrias contractus, commonly known as the odd beetle or tissue paper beetle, is the sole species in the monotypic genus Thylodrias within the family Dermestidae. Native to Asia, it has been introduced and become widespread in North America and parts of South America. The species exhibits pronounced sexual dimorphism, with males and females differing substantially in appearance. It is occasionally reported as a pest.
Timpanoga
Timpanoga is a genus of spiny crawler mayflies in the family Ephemerellidae, established by Needham in 1927. The genus contains a single described species, Timpanoga hecuba, commonly known to fly fishermen as the great red quill. This species is significant in angling communities as a model for artificial fly patterns imitating adult and subimago (dun) forms.
Tomolonus reductus
Tomolonus reductus is the sole species in the monotypic genus Tomolonus, a springtail in the family Tomoceridae. It is distinguished from other Tomoceridae by having only three ocelli in its eyepatch, a reduced number compared to relatives. The species was described in 1949 by H.B. Mills. Very few observations exist, with only three records documented on iNaturalist.
Toonglasa
Toonglasa is a genus of true bugs in the family Blissidae, first described by Distant in 1893. The genus contains a single described species, Toonglasa forficuloides. It is classified within the order Hemiptera, suborder Heteroptera, and infraorder Pentatomomorpha. The family Blissidae comprises seed bugs commonly associated with grasses and sedges.