Monotypic-genus
Guides
Trabeops aurantiacus
Trabeops aurantiacus is a wolf spider (family Lycosidae) and the sole species in the genus Trabeops. First described by Emerton in 1885 and later placed in its own genus by Roewer in 1959, this spider occurs in the United States and Canada. It represents a monotypic genus within the diverse wolf spider family.
Trichastylopsis albidus
Trichastylopsis albidus is a species of longhorn beetle in the family Cerambycidae, subfamily Lamiinae. It is the sole member of the monotypic genus Trichastylopsis. The species was described by John Lawrence LeConte in 1852. It is known from North America, with records from Mexico and the United States.
Trichinorhipis
Trichinorhipis is a monotypic genus of jewel beetles (Buprestidae) endemic to southern California. The sole species, Trichinorhipis knulli, measures under 4 mm and exhibits distinctive sexual dimorphism in antennae: males possess fan-like (flabellate) antennae adapted for detecting female sex pheromones, while females have unmodified serrate antennae. The genus is placed in its own subtribe (Trichinorphidina) within the tribe Xenorhipidini due to unique morphological characters distinguishing it from related genera Hesperorhipis and Xenorhipis.
Trichinorhipis knulli
Knull's Metallic Wood-boring Beetle
Trichinorhipis knulli is a minute jewel beetle (family Buprestidae) endemic to southern California, where it occurs in Riverside and Imperial Counties. It is the sole member of its monotypic genus, distinguished from related genera by its entire elytra covering the full abdomen and broadly rounded pronotum lacking lateral margins. Males exhibit highly modified flabellate antennae with expanded lamellae bearing numerous olfactory sensillae, an adaptation for detecting female sex pheromones. The species is rarely encountered in the field; most specimens have been reared from dead branches of jojoba (Simmondsia chinensis). At 3.6 mm, it is among the smallest buprestids.
Trichocanonura linearis
Trichocanonura linearis is a species of longhorn beetle in the subfamily Lamiinae, and the sole member of its monotypic genus. It was described by Skinner in 1905 based on specimens from Mexico. The species is characterized by its elongated, linear body form typical of many lamiine cerambycids. It is distributed in Mexico and the southern United States.
Tricholepidion
Tricholepidion
Tricholepidion is a genus of wingless insects in the order Zygentoma, containing a single described species, T. gertschi. It is endemic to the northern coast of California and represents the sole living member of the family Lepidotrichidae, with fossil relatives known from Eocene amber. Its taxonomic position is uncertain; molecular studies have sometimes recovered it as more distantly related to Pterygota than other Zygentoma, which would render Zygentoma paraphyletic. The genus is considered a 'living fossil' due to its isolated phylogenetic position and the extinction of all other family members.
Trimiomelba
Trimiomelba is a genus of myrmecophilous (ant-loving) rove beetles in the family Staphylinidae, subfamily Pselaphinae. The genus was established by Casey in 1897 and contains a single described species, T. dubia. These beetles belong to the tribe Trichonychini, a diverse group of small beetles often associated with ant colonies.
Tristyla alboplagiata
Tristyla alboplagiata is the sole species in the monotypic moth genus Tristyla, family Noctuidae. The species was described by John Bernhardt Smith in 1893. It is restricted to the southwestern United States.
Tropidarnis tectigera
Tropidarnis tectigera is a treehopper species in the family Membracidae, subfamily Smiliinae. It is the sole species in its genus. The species was described by Fowler in 1895. It is known from limited observations in the southwestern United States and parts of Central America.
Tropidolophus formosus
Great Crested Grasshopper
Tropidolophus formosus, the Great Crested Grasshopper, is the sole species in the monotypic genus Tropidolophus. This band-winged grasshopper is native to North America and has been reported in southeastern Wyoming and Colorado. The species is distinguished by a prominent crest on the pronotum, which gives rise to both its scientific and common names. It belongs to the subfamily Oedipodinae, a group characterized by enlarged hind wings often with dark bands.
Trudestra hadeniformis
Trudestra hadeniformis is a moth species in the family Noctuidae, described by Smith in 1894. It is the sole member of the genus Trudestra, which belongs to the tribe Hadenini within the subfamily Noctuinae. The species is known from North America, though detailed biological information remains limited. Its specific epithet 'hadeniformis' suggests resemblance to moths of the related genus Hada (formerly part of Hadenini).
Tsugaea
Tsugaea is a genus of tachinid flies in the family Tachinidae, subfamily Exoristinae, and tribe Eryciini. The genus was established by Hall in 1939 and contains a single described species, Tsugaea nox. These flies are distributed across North America, including Canada, the United States, and Mexico. As tachinid flies, members of this genus are likely parasitoids, though specific host associations remain undocumented in the available literature.
Tylcus
Tylcus is a monotypic genus of longhorn beetles (family Cerambycidae) containing a single species, Tylcus hartwegii. The genus was established by Casey in 1912 and is classified within the tribe Clytini of the subfamily Cerambycinae. As the sole representative of its genus, Tylcus hartwegii serves as the type species and defines the morphological characteristics of this otherwise poorly documented group.
Uhleriola
Uhleriola is a genus of dirt-colored seed bugs in the family Rhyparochromidae, containing a single described species, U. floralis. The genus was established by Horváth in 1908. Members of this genus belong to the diverse assemblage of true bugs commonly referred to as seed bugs or ground bugs.
Uhleriola floralis
Uhleriola floralis is a dirt-colored seed bug in the family Rhyparochromidae, the sole described species in its genus. It is native to North America, with confirmed records from the United States. Like other members of Rhyparochromidae, it belongs to the true bug infraorder Pentatomomorpha and possesses the piercing-sucking mouthparts characteristic of Hemiptera.
Uropodella
Uropodella is a genus of mites in the family Uropodellidae, established by Berlese in 1888. The genus contains a single described species, Uropodella laciniata. These mites belong to the order Mesostigmata, a group of predatory or parasitic mites with diverse ecological roles.
Valenus inornatus
Valenus inornatus is a species of longhorn beetle in the subfamily Lamiinae, and the sole member of its genus. It was described by Thomas L. Casey in 1891. The species is distributed in Mexico and the United States. As the only species in Valenus, it represents a monotypic genus within the tribe Acanthocinini.
Vandykea tuberculata
Serpentine Cypress Long-horned Beetle
Vandykea tuberculata is a species of longhorn beetle (family Cerambycidae) and the sole representative of its genus. It was described by Linsley in 1932 and is known from serpentine cypress habitats in western North America. The species is classified in the subfamily Cerambycinae and tribe Oemini.
Viridemas galena
Viridemas galena is a noctuid moth and the sole species in the monotypic genus Viridemas. First described by John Bernhardt Smith in 1908, this species is endemic to Arizona. The genus and species were established based on specimens collected in the southwestern United States, representing a distinct lineage within the subfamily Noctuinae.
Walterella ocellata
Walterella ocellata is the sole species in the monotypic moth genus Walterella, described by Barnes and McDunnough in 1910. The genus was erected by Harrison Gray Dyar Jr. in 1921. This noctuid moth is known from Arizona, with 35 observations recorded on iNaturalist. As a member of the family Noctuidae, it belongs to one of the largest families of Lepidoptera.
Xenomelanophila
Xenomelanophila is a monotypic genus of jewel beetles (Buprestidae) established by Sloop in 1937. The sole species, X. miranda, exhibits a highly specialized ecological association with forest fires. Females possess infrared-sensing organs that allow detection of smoldering wood for oviposition, making this genus one of the few known examples of pyrophilic beetles with confirmed thermosensory adaptations.
Xenotemna pallorana
Pallid Leafroller Moth
Xenotemna pallorana is a small tortricid moth and the sole member of its genus. It is widely distributed across North America from Alaska and western Canada to Florida and eastern Canada. The species is commonly known as the Pallid Leafroller Moth, reflecting its characteristic pale coloration and the leaf-rolling behavior typical of many tortricid larvae. Adults are active during the growing season, with larvae feeding on various deciduous trees and shrubs.
Xerociris wilsonii
Wilson's Wood-nymph Moth
Xerociris wilsonii, commonly known as Wilson's Wood-nymph Moth, is a monotypic species in the family Noctuidae, subfamily Agaristinae. The genus was erected by Theodore Dru Alison Cockerell in 1904, with the species originally described by Augustus Radcliffe Grote in 1863. It is found in the US state of Texas and has been recorded in North America.
Xyloterinus
Xyloterinus is a monotypic genus of ambrosia beetles in the family Curculionidae, containing the single species Xyloterinus politus. Native to eastern North America, this beetle infests both hardwood and softwood trees, particularly recently fallen or cut timber. The species cultivates fungal gardens in wood galleries and has been extensively studied for its symbiotic relationships with yeasts and other fungi.
Xyloterinus politus
Polished Bark Beetle
Xyloterinus politus is a North American ambrosia beetle in the family Curculionidae, historically placed in Scolytidae. It is the sole species in the monotypic genus Xyloterinus. The species exhibits obligate mutualism with cultivated fungi, excavating galleries in hardwood and softwood trees where it grows and feeds on ambrosial fungi rather than wood tissue. Females initiate gallery construction and maintain fungal gardens; males do not excavate galleries and are excluded from active attacks. The beetle overwinters as an adult in old galleries and cradles.
Xystopeplus
Xystopeplus is a genus of moths in the family Noctuidae, established by Franclemont in 1937. The genus contains a single recognized species, Xystopeplus rufago. These moths belong to the tribe Xylenini within the subfamily Noctuinae. The genus is documented in North American fauna and is represented in natural history collections and citizen science observations.
Zacotus matthewsii
Zacotus matthewsii is a ground beetle and the sole species in its genus. It belongs to the subfamily Broscinae within Carabidae. The species is endemic to western North America, with records from Alaska, Canada, and the contiguous United States. Its monotypic genus status makes it taxonomically distinctive among North American carabids.
Zelicodes linearis
Dusty-winged Tan
Zelicodes linearis is the sole species in the monotypic moth genus Zelicodes, family Erebidae. It was first described by Augustus Radcliffe Grote in 1883 (originally as Litognatha linearis), with the genus established in 1896. The species is known from Arizona, USA, and is commonly called the Dusty-winged Tan. As a member of subfamily Calpinae, it belongs to a group of moths often associated with fruit-feeding behaviors, though specific biological details for this species remain limited.
Zoniagrion exclamationis
Exclamation Damsel
Zoniagrion exclamationis, commonly known as the Exclamation Damsel, is a species of damselfly in the family Coenagrionidae. It is the sole species in its genus and is endemic to western North America. The species was first described by Selys in 1876 and is recognized by its distinctive coloration and patterning. It is a relatively well-documented damselfly with over 300 observations recorded on citizen science platforms.
Zotheca
elder moth
Zotheca is a monotypic genus of moths in the family Noctuidae, containing a single species, Zotheca tranquilla (the elder moth). The genus is restricted to western North America, where adults are active during summer months. The common name derives from the larval host plant, elderberry (Sambucus).
Zygobarinus
Zygobarinus is a genus of flower weevils in the family Curculionidae, established by W.D. Pierce in 1907. The genus contains a single described species, Zygobarinus coelestinus. As a member of the Curculionidae, it possesses the characteristic rostrum (snout) typical of weevils. The genus is classified within the suborder Polyphaga and infraorder Cucujiformia.