Rare
Guides
Fitchiella robertsonii
ball-nosed planthopper
Fitchiella robertsonii is a rare, diminutive planthopper historically known from fewer than 20 collection sites across North America. The species was considered potentially extinct until its rediscovery in Iowa tallgrass prairie in 2008, with subsequent 12-year research yielding 219 specimens—representing 90% of all known collections. Adults measure less than 5 mm but can leap 35 inches in a single jump, roughly 250 times their body length. The species exhibits both brachypterous (short-winged, flightless) and macropterous (long-winged) forms.
Flexamia huroni
Huron River Leafhopper
Flexamia huroni is a leafhopper species in the family Cicadellidae, described by Bess & Hamilton in 1999. It belongs to the genus Flexamia, a group of leafhoppers known for their specialized host plant associations with grasses. The species is named after the Huron River in Michigan, where it was first collected. Like other members of the genus, it likely exhibits strong ecological dependence on specific grass host plants.
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lobal-biodiversity-information-facilityesbiodiversity-image-portalspanish-collectionstype-specimenlichenantarcticabernensisliyellowstoneFloridacris mariona
Floridacris mariona is a species of grasshopper in the family Acrididae, first described by Daniel Otte in 2014. It is endemic to Florida and belongs to a genus with limited species diversity. The species is known from very few observations, reflecting either genuine rarity or restricted habitat specificity.
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.
Franclemontia interrogans
Franclemont's Switch Cane Borer Moth
Franclemontia interrogans is a noctuid moth species found in North America. The species is known by the common name Franclemont's Switch Cane Borer Moth. It belongs to a small genus named after the lepidopterist John G. Franclemont. Published records for this species are extremely limited, with only three observations documented on iNaturalist as of the knowledge cutoff.
Gambrinus olentangyi
Olentangy River Beetle
Gambrinus olentangyi is a species of metallic wood-boring beetle in the family Buprestidae. It was described from the Olentangy River region in Ohio and is associated with riparian habitats. The species is rarely encountered in collections and remains poorly known biologically.
Gastrodynerus vanduzeei
Gastrodynerus vanduzeei is a species of potter wasp in the subfamily Eumeninae, described by Bohart in 1948. The genus Gastrodynerus is a small group within the Vespidae, and this species is among the least documented members of the family. Very few observations or collections have been recorded, with iNaturalist showing only four observations total. The specific epithet honors the entomologist Edward P. Van Duzee.
Geocolus
Geocolus is a monotypic genus of clown beetles (family Histeridae) containing a single described species, G. caecus. The genus is notable for its highly specialized subterranean ecology. The sole species exhibits extreme morphological adaptations for underground life, including near-complete eye reduction and depigmentation.
Geomysaprinus xerobatis
Geomysaprinus xerobatis is a species of clown beetle in the family Histeridae. It belongs to the genus Geomysaprinus, a group specialized for association with fossorial mammals. The species epithet "xerobatis" references its documented association with desert-dwelling pocket gophers.
Geopsammodius morrisi
Geopsammodius morrisi is a small scarab beetle in the subfamily Aphodiinae, described by Paul Skelley in 2006. It belongs to a genus of psammophilic (sand-dwelling) beetles within the tribe Psammodiini. The species is known from a limited number of records in Florida, USA. Like other members of its genus, it is likely associated with sandy habitats, though specific ecological details remain poorly documented.
Geopsammodius relictillus
relictual tiny sand-loving scarab
Geopsammodius relictillus is a small aphodiine dung beetle in the family Scarabaeidae, described from Florida in 1991. The species epithet "relictillus" refers to its relictual status, suggesting it may represent a remnant population of a formerly more widespread group. It belongs to the tribe Psammodiini, whose members are commonly known as sand-loving scarabs due to their association with sandy habitats.
Gnathonaroides
Gnathonaroides is a monotypic genus of sheet-web weaving spiders (family Linyphiidae) containing the single species Gnathonaroides pedalis. It was described in 1938 by arachnologists S. C. Bishop and C. R. Crosby. The genus is known only from Canada and the United States, with extremely limited observational records.
Gomphurus gonzalezi
Tamaulipan Clubtail
Gomphurus gonzalezi, commonly known as the Tamaulipan clubtail, is a dragonfly species in the family Gomphidae. It is restricted to a narrow geographic range along the lower Rio Grande, occurring in Texas, USA and San Luis Potosí, Mexico. The species was originally described by Dunkle in 1992. The genus Gomphurus was elevated from subgenus to genus rank in 2017, reclassifying this species from Gomphus.
Goniusa
Goniusa is a genus of rove beetles in the family Staphylinidae, subfamily Aleocharinae, and tribe Athetini. The genus was established by Casey in 1906 and contains at least three described species. Members of this genus are small beetles with the characteristic short elytra of rove beetles, leaving most of the abdomen exposed.
Grotellaforma lactea
Grotellaforma lactea is a small noctuid moth described by Stretch in 1885. The species was originally placed in the genus Cisthene before being transferred to the monotypic genus Grotellaforma. It is known from arid regions of the southwestern United States, with type specimens collected in California and Arizona. The specific epithet 'lactea' refers to the milk-white coloration of the adult.
Grylloblatta chirurgica
Mount Saint Helens Grylloblattid, Mount Saint Helens grylloblatid
Grylloblatta chirurgica is a species of ice crawler endemic to southwestern Washington state, specifically associated with high-elevation habitats and ice caves near Mount St. Helens in Skamania County. Described by Gurney in 1961, it is one of the rarest and most geographically restricted members of the relict order Notoptera (Grylloblattodea). The species persists in cold, stable microhabitats including glacial ice fields and subterranean ice formations. Its extremely limited distribution and specialized habitat requirements make it vulnerable to environmental change.
Hadromychus
handsome fungus beetles
Hadromychus is a genus of handsome fungus beetles in the family Endomychidae, established by Bousquet & Leschen in 2002. The genus is monotypic, containing only one described species, Hadromychus chandleri. As members of Endomychidae, these beetles are associated with fungal substrates. The genus is poorly known due to its rarity and limited collection records.
Hebardacris
Mount Whitney grasshopper (for H. albida)
Hebardacris is a genus of spur-throated grasshoppers in the family Acrididae, established by Rehn in 1952. The genus contains at least three described species: H. albida (Mount Whitney grasshopper), H. excelsa, and H. mono. These species are native to western North America, with records concentrated in California. The genus belongs to the tribe Podismini within the subfamily Melanoplinae.
Hebata ruficeps
Hebata ruficeps is a species of leafhopper in the family Cicadellidae, first described by Van Duzee in 1917. The species is known from California, with very few documented observations. Like other members of the family, it likely feeds on plant sap using piercing-sucking mouthparts. Data on its biology and ecology remain limited due to its rarity in collections and observations.
Heimbra
A small genus of chalcidoid wasps in the family Eurytomidae, subfamily Heimbrinae. Species of Heimbra are poorly represented in entomological collections and have been documented from Mexico, Argentina, Paraguay, and Brazil. At least three species are recognized: H. bicolor, H. dioneae, and H. pulchra. The genus is characterized by morphological features typical of Heimbrinae, though detailed biological information remains limited.
Hemigrotella
Hemigrotella is a monotypic moth genus in the family Noctuidae, containing the single species Hemigrotella argenteostriata. The genus was described in 1918 by William Barnes and James Halliday McDunnough. It is endemic to southern California. The genus belongs to the tribe Psaphidini within the subfamily Amphipyrinae.
Hesperoboreus
Hesperoboreus is a genus of snow scorpionflies (Mecoptera: Boreidae) established by Norman Penny in 1977. Members of this genus are small, wingless insects adapted to cold environments. The genus is distinguished from the related Boreus by morphological features of the male genitalia. Very few observations exist, with only three records documented on iNaturalist as of the knowledge cutoff.
Hexatoma sculleni
Hexatoma sculleni is a crane fly species in the family Limoniidae, described by Charles Paul Alexander in 1943. It belongs to a genus of small to medium-sized crane flies characterized by reduced wing venation and relatively short legs compared to true crane flies (Tipulidae). The species is known from a limited geographic range in the western United States. Very few observations exist, suggesting it is either genuinely rare or underreported.
Hexepeolini
Hexepeolini is a monotypic tribe of cuckoo bees within the subfamily Nomadinae (family Apidae). The tribe contains a single genus, Hexepeolus, which in turn contains only one species, Hexepeolus rhodogyne. As cuckoo bees, members of this tribe are brood parasites that do not construct nests or collect pollen. The extreme rarity of this tribe—represented by only two observations on iNaturalist—reflects its narrow geographic distribution and specialized ecological requirements.
Hexepeolus
Hexepeolus is a monotypic genus of cuckoo bees in the family Apidae, established by Linsley and Michener in 1937. It represents the sole genus within the tribe Hexepeolini and contains only one described species, Hexepeolus rhodogyne. As a member of the subfamily Nomadinae, these bees exhibit kleptoparasitic behavior, laying eggs in the nests of other bee species. The genus is rarely encountered, with minimal observational records.
Hilarimorphidae
hilarimorphid flies
Hilarimorphidae is a small family of flies (Diptera) with uncertain phylogenetic placement. They have been variously associated with Acroceridae or Bombyliidae within the superfamily Asiloidea. The family is primarily Nearctic in distribution and includes both extant and fossil species.
Hodophylax tolandi
Hodophylax tolandi is a species of robber fly (family Asilidae) described by Wilcox in 1961. Robber flies are predatory dipterans characterized by their stout bodies, strong legs, and piercing mouthparts used to capture and subdue prey. This species belongs to the genus Hodophylax, a small group within the diverse Asilidae family. Published records indicate this species is known from limited observations, with iNaturalist documenting only four observations as of the source date.
Holopleurini
Holopleurini is a monotypic tribe of longhorn beetles (Cerambycidae) containing a single genus, Holopleura, and a single species, Holopleura marginata. The tribe is classified within the subfamily Cerambycinae. Information on this group is extremely limited due to its rarity and restricted distribution. The species appears to be endemic to a narrow geographic range in western North America.
Homocerynea cleoriformis
Homocerynea cleoriformis is the sole species in the monotypic moth genus Homocerynea. The species was described by William Barnes and James Halliday McDunnough in 1913 from material collected in Arizona. It belongs to the family Erebidae (formerly classified in Noctuidae). No observations have been recorded in iNaturalist, indicating extreme rarity or possible extinction.
Homorthodes carneola
Homorthodes carneola is a species of owlet moth in the family Noctuidae, described by James Halliday McDunnough in 1943. It belongs to the genus Homorthodes, a group of small to medium-sized noctuid moths found primarily in North America. Very few observations of this species have been documented, suggesting it is either rare, cryptic, or restricted to specific habitats. The species epithet 'carneola' derives from Latin, referencing a flesh-colored or pinkish appearance.
Horologion
Horologion is one of the rarest and most enigmatic carabid beetle genera, containing two known species of troglomorphic ground beetles endemic to the middle Appalachian Mountains. The genus remained monotypic for over 60 years after its description in 1932, with a second species discovered in Virginia in 1991 and described in 2024. Phylogenetic analysis places Horologion in supertribe Trechitae as sister to the Gondwanan tribe Bembidarenini, making tribe Horologionini a relict lineage with no close relatives in the Northern Hemisphere.
Hubbellia
Hubbellia is a monotypic genus of shield-backed katydids in the family Tettigoniidae, established by Hebard in 1927. The sole described species, H. marginifera, is among the rarest katydids in the United States, with approximately 40 specimens collected despite over a century of entomological work. Its extreme rarity and arboreal habits have made it a notable subject for orthopteran researchers.
Hydrochara rickseckeri
Ricksecker's Water Scavenger Beetle
Hydrochara rickseckeri is a rare, California-endemic water scavenger beetle in the family Hydrophilidae. It is one of the few Hydrochara species native to North America. The species was described by Horn in 1895 and remains poorly known due to its limited distribution and scarcity of observations.
Hylaeus graenicheri
Graenicher's Masked Bee, Graenicher's Yellow-faced Bee
Hylaeus graenicheri is a species of masked bee in the family Colletidae, endemic to southern Florida. It is one of only five Colletidae species restricted entirely to Florida. Like other members of the genus Hylaeus, it is nearly hairless and wasp-like in appearance, with yellow or white facial markings. The species is poorly known due to its restricted range and limited study.
Hylocrinus
Hylocrinus is a genus of darkling beetles (Tenebrionidae) established by Thomas L. Casey in 1907. The genus is represented by very few observations, with only 14 records on iNaturalist, suggesting it is either genuinely rare, cryptic, or poorly sampled. It occurs in the Nearctic and Neotropical regions. Little is known about its biology due to its obscurity.
Hylogomphus apomyius
Banner Clubtail
Hylogomphus apomyius, commonly known as the Banner Clubtail, is a dragonfly species in the family Gomphidae. It is one of several small clubtail species within the genus Hylogomphus, characterized by relatively modest abdominal clubbing compared to larger gomphids. The species was described by Donnelly in 1966 and occurs in eastern North America. It is associated with riverine habitats and is considered uncommon throughout its range.
Hypochilus bernardino
A rare spider species in the family Hypochilidae, described by Catley in 1994. The specific epithet "bernardino" references the San Bernardino Mountains of southern California, where the species was first discovered. Hypochilidae is a small family of spiders with distinctive morphological features and limited geographic distribution.
Hypothyce
May beetles, Junebugs
Hypothyce is a genus of scarab beetles in the subfamily Melolonthinae, containing four described species in the United States. All species are restricted to isolated sandhill habitats along the North American Coastal Plain. The genus exhibits pronounced geographic isolation, with each species known from a single state: Texas, Georgia, or Alabama. Several species remain poorly known, with females undescribed for three of four species.
Hystrichophora loricana
Coppery Orbexilum
Hystrichophora loricana is a rare tortricid moth species endemic to the United States. It belongs to the leafroller moth family, with caterpillars that construct shelters by rolling leaves. The species has a highly specialized diet, feeding exclusively on Orbexilum onobrychis. It is poorly documented in scientific literature and field observations.
Idiostatus wymorei
Wymore's Shieldback
Idiostatus wymorei is a shieldback katydid described by Caudell in 1934. It belongs to the genus Idiostatus, a group of flightless katydids characterized by reduced wing pads and shield-like pronota. The species is known from California and is among the least documented members of its genus, with very few observations recorded.
Illinoia crystleae
Pale-streaked Honeysuckle Aphid
Illinoia crystleae is a species of aphid in the family Aphididae, commonly known as the Pale-streaked Honeysuckle Aphid. It belongs to the genus Illinoia, which comprises aphids primarily associated with woody shrubs and trees. The species was described by Smith and Knowlton in 1939. Very few observations of this species have been documented, with only three records in iNaturalist, indicating it is either genuinely rare, underreported, or restricted to specific host plants or geographic regions.
Inopsis funerea
Inopsis funerea is a moth species in the family Erebidae, first described by Augustus Radcliffe Grote in 1883. The species is known from very few records in North America, specifically Arizona and South Carolina, indicating a disjunct or poorly sampled distribution. Adults have been documented in June, suggesting a restricted seasonal flight period. The genus Inopsis belongs to the tribe Lithosiini, a group of lichen moths typically characterized by muted coloration and cryptic patterning.
Ischnura gemina
San Francisco Forktail
Ischnura gemina is a small damselfly endemic to the San Francisco Bay Area of California, with a total range of less than 500 square miles. It is considered one of the rarest odonates in the United States. The species inhabits coastal wetland ecosystems and has been observed to have an unusually long adult lifespan for a damselfly, likely an adaptation to the region's foggy climate. Populations have declined due to urbanization and habitat destruction, though the species shows some resilience to certain forms of habitat degradation.
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.
Juniperella
Juniperella is a monotypic genus of beetles in the family Buprestidae, containing only the single species Juniperella mirabilis. The genus was established by Knull in 1947. It belongs to the subfamily Buprestinae and tribe Melanophilini. Knowledge of this genus is extremely limited due to its rarity and the scarcity of observations.
Juniperthia indella
Juniperthia indella is a species of planthopper in the family Achilidae, first described by Ball in 1933. It belongs to the tribe Plectoderini within the subfamily Myconinae. Records indicate this species occurs in the southwestern United States.
Keltonia rubrofemorata
Keltonia rubrofemorata is a species of plant bug in the family Miridae, described by Knight in 1966. It belongs to the genus Keltonia, a small group of mirid bugs. The species is known from limited records in Florida, USA. Very little published information exists regarding its biology or ecology.
Knowltonia atrifasciata
Knowltonia atrifasciata is a rarely encountered species of metallic wood-boring beetle in the family Buprestidae. The genus Knowltonia is small and poorly known, with K. atrifasciata being one of the most uncommon members. Field observations indicate an association with Atriplex (saltbush) species, particularly Atriplex canescens (fourwing saltbush). Adults display the characteristic metallic coloration of buprestids and are active in late spring. The species has been documented from the Rio Bosque Wetland Park in El Paso, Texas, and likely occurs more broadly in the Chihuahuan Desert region.
Lariversius tibialis
Lariversius tibialis is the sole species in the monotypic genus Lariversius, a genus of darkling beetles in the family Tenebrionidae. Described by Blaisdell in 1947, this species is known from limited collection records. The genus name honors L. Rivers, and the specific epithet refers to the tibial structure.
Lepidomyia micheneri
Michner's Scaleback
Lepidomyia micheneri is a species of hoverfly (family Syrphidae) described by Fluke in 1953. It belongs to the tribe Brachyopini within the subfamily Eristalinae. The species is known from very few observations, with only two records documented on iNaturalist. It is commonly referred to as "Michner's Scaleback."