Endemic
Guides
Macrobaenetes algodonensis
Algodones Sand Treader Cricket
Macrobaenetes algodonensis, the Algodones Sand Treader Cricket, is a species of camel cricket described by Tinkham in 1962. It belongs to the family Rhaphidophoridae, a group of wingless, hump-backed crickets commonly known as camel or cave crickets. The species is endemic to the Algodones Dunes region of southeastern California, where it inhabits sandy desert environments. As a member of the genus Macrobaenetes, it shares adaptations for life in loose sand with related sand treader crickets.
Macrobaenetes sierrapintae
Sierra Pinta Giant Sand-treader Cricket
Macrobaenetes sierrapintae is a species of camel cricket in the family Rhaphidophoridae, endemic to the Sierra Pinta mountains of southwestern Arizona. Described by Tinkham in 1962, it belongs to a genus specialized for life in sandy desert habitats. The species is among the largest members of the genus Macrobaenetes. Like other members of this genus, it possesses enlarged hind tarsi adapted for locomotion on loose sand.
Macrobaenetes valgum
Coachella giant sand treader cricket
Macrobaenetes valgum, the Coachella giant sand treader cricket, is a species of cave cricket in the family Rhaphidophoridae. It is endemic to the United States and has been recorded from California. Like other members of its genus, it is adapted to arid sandy habitats. The species was described by Strohecker in 1960.
Macrosaccus neomexicanus
Macrosaccus neomexicanus is a minute leaf-mining moth in the family Gracillariidae, described by Davis in 2011. The species is endemic to the southwestern United States, where it is known from Arizona and New Mexico. Its larvae are specialized feeders on New Mexico locust (Robinia neomexicana), creating distinctive tentiform leaf mines. The specific epithet references its host plant rather than its geographic distribution.
Macroscytalus
Macroscytalus is a genus of weevils (family Curculionidae) established by Thomas Broun in 1881. It is native to New Zealand and is part of the diverse Australasian weevil fauna. The genus contains relatively few described species and remains poorly documented in published literature.
Macroscytalus chisosensis
Macroscytalus chisosensis is a species of seed bug in the family Lygaeidae. It is endemic to the Chisos Mountains of Big Bend National Park in Texas, USA. The species is known from a limited number of specimens collected at high elevations in this isolated mountain range. Its restricted distribution makes it a notable example of localized endemism in the Chihuahuan Desert region.
Macrosiphum tuberculaceps
sweet-after-death aphid
Macrosiphum tuberculaceps is an aphid species endemic to the Pacific Northwest region of North America. It is commonly known as the sweet-after-death aphid due to its exclusive association with its host plant, sweet-after-death (Achlys triphylla). The species exhibits distinctive morphological features including antennae longer than its teardrop-shaped body, short siphunculi inflated at the base with blackish tips, and legs longer than the body length. Its highly specialized host relationship makes it a notable example of monophagy among aphids.
Macrotylus tristis
Macrotylus tristis is a species of plant bug in the family Miridae, described by Uhler in 1890. The species is endemic to California, where it has been documented from a small number of observations. As a member of the genus Macrotylus, it belongs to a group of mirids often associated with specific host plants.
Maculamiris insulanus
Maculamiris insulanus is a species of plant bug in the family Miridae, described by Weirauch in 2006. The species is endemic to the Channel Islands of California, specifically Santa Catalina Island and San Clemente Island. As a member of the diverse Miridae family, it belongs to one of the largest families of true bugs, though specific ecological details for this island-endemic species remain poorly documented.
Madoniella chiricahua
Madoniella chiricahua is a species of checkered beetle in the family Cleridae. It is known from the Chiricahua Mountains of southeastern Arizona, a region characterized by high biodiversity and endemism within the Madrean Sky Islands. The species has been documented from a single observation, indicating it is likely rare or poorly sampled. Its specific epithet refers to the Chiricahua Mountains, the type locality.
Magicicada septendecula
Decula Periodical Cicada
Magicicada septendecula is one of three species of 17-year periodical cicadas endemic to the eastern United States. It is typically the rarest of the three species in mixed-species populations and exhibits stronger habitat specificity than its congeners. The species prefers upland woodland habitats dominated by hickories and walnuts, particularly Carya glabra (pignut hickory), and shows a strong association with Juglandaceae host trees. First described in 1962, it has been recorded from Connecticut southward through the eastern states, with the northeastern-most record from Totoket Mountain in North Branford, Connecticut in 2013. M. septendecula is distinguished from M. septendecim by its smaller body size and hind tibial length (less than 6.3 mm versus 6.3 mm or greater). The species exhibits greater susceptibility to delayed emergence compared to other Magicicada species, which may contribute to its comparative rarity.
Mallophora atra
Black Bee-Killer, Black Bee Killer
Mallophora atra, commonly known as the black bee-killer, is a species of robber fly in the family Asilidae. It is found across much of Brazil, with records from 19 states including Amazonas, Pará, São Paulo, and Rio Grande do Sul. As a member of the genus Mallophora, it is a large, powerful predatory fly known for capturing and feeding on bees and other insects. The species was first described by Macquart in 1834.
Marchena minuta
Marchena minuta is a small jumping spider and the sole described species in its genus. It is endemic to western North America, where it inhabits the bark of coniferous trees. The species represents the only North American member of the subfamily Heliophaninae. Its distribution is concentrated along the Pacific coast, with records from California, Washington, and Nevada.
Marinarozelotes lyonneti
Marinarozelotes lyonneti is a ground spider in the family Gnaphosidae, endemic to the Azores archipelago. Originally described by Audouin in 1826 as Drassus lyonnetii, this species was later transferred to the genus Marinarozelotes. It has been recorded from five islands in the central and western Azores. Like other gnaphosids, it is likely a nocturnal, cursorial hunter.
Mectemycor
Mectemycor is a genus of soft-bodied plant beetles comprising three known species, all endemic to California. The genus was established by Majer in 1995 and is currently classified in the family Mauroniscidae, having been historically placed in Melyridae. All three species—M. linearis, M. sericeus, and M. strangulatus—are restricted to western North America.
Megachile davidsoni
Megachile davidsoni is a solitary bee species in the family Megachilidae, first described by Theodore Dru Alison Cockerell in 1902. It belongs to the leafcutter bee genus Megachile, whose members are characterized by cutting leaf pieces to line their nest cavities. The species is known from a restricted geographic range in southwestern California. Like other Megachile species, it is a solitary cavity-nesting bee that carries pollen on the underside of its abdomen rather than on its legs.
Megachile pruina
Hoary Leafcutter Bee
Megachile pruina, commonly known as the Hoary Leafcutter Bee, is a solitary leafcutter bee in the family Megachilidae. It is medium-sized (11–13 mm) and exhibits sexual dichromatism, with females often appearing very dark. The species occurs along coastal habitats from Virginia to Florida and westward to Texas, with an isolated population in Bermuda that represents a genetically distinct evolutionary lineage. Bermuda's population is classified as Vulnerable and is the only arthropod protected under the Bermuda Protected Species Act.
Megacraspedus plutella
Megacraspedus plutella is a small twirler moth (family Gelechiidae) described by V.T. Chambers in 1874. It is the only member of its genus known to occur north of Mexico, with records limited to the southwestern United States. The species is characterized by distinctive forewing coloration with creamy white margins against a dark gray-brown ground color.
Megarthrus pictus
Megarthrus pictus is a rove beetle (Staphylinidae) endemic to western North America. It is distinguished from other Nearctic Megarthrus species by its bicolored elytra and angulate temples. The body is predominantly brownish yellow in coloration. It is the only Nearctic species in its genus exhibiting this combination of traits that is endemic to Western North America.
Megasoma sleeperi
Sleeper's Elephant Beetle
Megasoma sleeperi is a species of rhinoceros beetle in the family Scarabaeidae. It is endemic to the Algodones Dunes of southeastern California and adjacent areas of southwestern Arizona and northwestern Mexico. Like other members of the genus Megasoma, it is among the largest beetles in North America. Males possess prominent horns used in combat with other males. The species was described by Hardy in 1972 and is named in honor of collector R. C. Sleeper.
Megathymus cofaqui
Cofaqui Giant-Skipper
Megathymus cofaqui, the Cofaqui giant-skipper, is a butterfly in the family Hesperiidae. It is endemic to a narrow north–south corridor through central Georgia, United States. The species belongs to the genus Megathymus, a group commonly known as giant-skippers due to their relatively large size among skippers.
Megatibicen
Great Cicadas
Megatibicen is a genus of North American cicadas established in 2016, comprising approximately 10 species previously classified under Tibicen, Neotibicen, Ameritibicen, and Gigatibicen. These are large-bodied cicadas commonly known as 'Great Cicadas,' with males producing distinctive calling songs using tymbal organs. The genus exhibits notable diversity in the south-central and southwestern United States, including a recently described endemic species from the Mescalero-Monahans shinnery sands.
Megatibicen dorsatus
Bush Cicada, Giant Grassland Cicada, Grand Western Cicada, Splendid Prairie Cicada
Megatibicen dorsatus, commonly known as the Bush Cicada or Giant Grassland Cicada, is a large, striking cicada species endemic to the tallgrass and shortgrass prairies of the central United States. Adults are among the largest North American cicadas, measuring approximately 57 mm in length, with distinctive white waxy markings on a dark body. Males produce loud, characteristic songs using internal tymbal organs to attract females. The species has an annual life cycle with staggered emergences, with adults active primarily from July through September. M. dorsatus is frequently found perched on low vegetation in open grassland habitats, where its contrasting coloration provides surprising cryptic protection. Adult males serve as hosts for the acoustically hunting sarcophagid parasitoid Emblemasoma erro.
Megatibicen harenosus
Great Mescalero Cicada
Megatibicen harenosus is a recently described cicada species endemic to the Mescalero-Monahans shinnery sands of New Mexico and Texas. It was formally described in 2017 based on distinct male genital morphology, color pattern, calling song characteristics, and ecological preferences. The species is closely related to M. tremulus, from which it differs significantly in four temporal song characters. Its restricted distribution in sandy habitats represents one of the most southwestern ranges of any Megatibicen species.
Megischus arizonicus
Arizona Crown Wasp
Megischus arizonicus is a species of crown wasp in the family Stephanidae, first described by Townes. Originally known only from Arizona, USA, the species has since been documented in central Mexico, expanding its known range significantly. Like other stephanids, it is a parasitoid wasp associated with wood-boring beetle larvae. The species exhibits the characteristic elongated, crown-like structure on the head that gives the family its common name. Records remain sparse, with only a handful of observations documented in biodiversity databases.
Megobrium
Megobrium is a monotypic genus of longhorn beetles in the family Cerambycidae, containing the single species Megobrium edwardsii. The genus was established by John Lawrence LeConte in 1873. It is endemic to California and classified within the subfamily Cerambycinae and tribe Hyboderini.
Melanderia
Melanderia is a genus of long-legged flies (family Dolichopodidae) endemic to the West Coast of the United States. Members of this genus inhabit the intertidal zone, an unusual habitat for dolichopodid flies. Adults possess modified labellae that resemble mandibles, a distinctive morphological adaptation. The genus comprises four described species divided into two subgenera: Melanderia and Wirthia.
Melanocinclis gnoma
Melanocinclis gnoma is a small moth in the family Cosmopterigidae, described by Ronald Hodges in 1978. It belongs to a genus of microlepidopterans within the superfamily Gelechioidea. The species is known from very limited records.
Melanopleurus fuscosus
Melanopleurus fuscosus is a seed bug in the family Lygaeidae, described by Brailovsky in 1977. The species has been documented from Santa Cruz Island off the coast of California, with 211 observations recorded on iNaturalist. As a member of the Lygaeidae, it belongs to a family of true bugs commonly known as seed bugs, though specific biological details for this species remain limited in published literature.
Melanoplus cameronis
Brownsville Short-wing Grasshopper
Melanoplus cameronis, the Brownsville Short-wing Grasshopper, is a spur-throated grasshopper described by Roberts in 1947. It is endemic to southern Texas, with confirmed records from the Brownsville area. The species belongs to the large genus Melanoplus, which contains many North American grasshoppers of economic and ecological significance. It is considered a short-winged species, suggesting reduced dispersal capability compared to fully winged relatives.
Melanoplus carnegiei
Carnegie Short-wing Grasshopper, Carnegie's Locust
Melanoplus carnegiei is a species of spur-throated grasshopper in the family Acrididae, first described by Morse in 1904. It is commonly known as the Carnegie Short-wing Grasshopper or Carnegie's Locust. The species is endemic to the southeastern United States.
Melanoplus discolor
contrasting spur-throat grasshopper
Melanoplus discolor, known as the contrasting spur-throat grasshopper, is a species of spur-throated grasshopper in the family Acrididae. It is native to North America and has been documented in Colorado, Texas, and northeastern Mexico. The species belongs to the Melanoplus discolor species group, which includes seven newly described flightless grasshopper species from central Texas, highlighting the ecological uniqueness of the Edwards Plateau region.
Melanoplus forcipatus
toothcercus shortwing grasshopper, broad cercus scrub grasshopper
Melanoplus forcipatus is a species of spur-throated grasshopper endemic to a restricted area of central Florida. It is known only from scrub and sandhill habitats in Highlands and Orange counties. The species was described by Hubbell in 1932 and is one of several shortwing grasshoppers in the genus Melanoplus with limited distributions.
Melanoplus indicifer
spinecercus short-wing grasshopper, east coast scrub grasshopper
Melanoplus indicifer is a species of spur-throated grasshopper endemic to a restricted range in Florida. It inhabits scrub habitats on the Atlantic Coastal Ridge in Palm Beach County. The species is characterized by short wings, a trait reflected in one of its common names. Its limited distribution makes it vulnerable to habitat loss from development and fire suppression.
Melanoplus islandicus
island short-wing grasshopper, forest locust, island locust
Melanoplus islandicus is a spur-throated grasshopper in the family Acrididae, found in coastal regions of Alaska, Canada, and the Great Lakes area. Populations have declined due to habitat loss and invasive species, prompting conservation concern. The United States Fish and Wildlife Service proposed it for Endangered Species Act listing in 2003, though it remains unlisted.
Melanoplus nanciae
Ocala clawcercus grasshopper
Melanoplus nanciae, known as the Ocala clawcercus grasshopper, is a species of spur-throated grasshopper described by Deyrup in 1997. It belongs to the diverse genus Melanoplus within the family Acrididae. The species is known from a restricted geographic range in Florida. Published records indicate it is rarely encountered, with limited observational data available.
Melanoplus oklahomae
Oklahoma spur-throat grasshopper
Melanoplus oklahomae is a species of spur-throated grasshopper described by Hebard in 1937. It belongs to the diverse genus Melanoplus, which contains many North American grasshopper species. The species is endemic to Oklahoma and surrounding regions in North America. Like other members of its genus, it possesses the characteristic spur on the prosternum that gives the group its common name.
Melanoplus ordwayae
Trail Ridge Scrub Grasshopper, Ordway Melanoplus Grasshopper
Melanoplus ordwayae is a species of spur-throated grasshopper in the family Acrididae, described by Deyrup in 1997. It is endemic to Florida, specifically associated with the scrub habitat of the Lake Wales Ridge region. The species is known from very few observations and is considered rare and potentially threatened by habitat loss. Its common name references the Trail Ridge, a prominent geologic feature in its range.
Melanoplus oreophilus
Mount Hood Short-wing Grasshopper
Melanoplus oreophilus is a spur-throated grasshopper species endemic to the Mount Hood region of Oregon. The species is characterized by reduced wing development, a trait reflected in its common name. It inhabits high-elevation alpine environments and has a restricted geographic range.
Melanoplus peninsularis
Melanoplus peninsularis is a species of grasshopper in the family Acrididae, described by Hubbell in 1932. The specific epithet "peninsularis" refers to its restricted distribution on the Florida peninsula. It is a member of the large genus Melanoplus, which contains many North American grasshopper species. The species appears to be uncommon, with limited observation records.
Melanoplus tequestae
tequestae scrub grasshopper, tequesta grasshopper
Melanoplus tequestae is a spur-throated grasshopper endemic to Florida scrub habitat. It is restricted to three counties in central Florida and is one of the more narrowly distributed members of the large genus Melanoplus. The species has been studied for its mating behavior, which involves male calling songs and visual courtship displays.
Melanoplus withlacoocheensis
Withlacoochee Grasshopper
Melanoplus withlacoocheensis is a species of spur-throated grasshopper in the family Acrididae, described in 1998 from Florida. It belongs to a large genus of North American grasshoppers that includes many economically significant agricultural pests. The species is named for the Withlacoochee River region of central Florida, where the type specimens were collected. It appears to be a localized endemic with limited distribution records.
Melanotus dichrous
Melanotus dichrous is a click beetle species in the family Elateridae, first described by Erichson in 1841 under the basionym Cratonychus dichrous. The species is known from the Azores archipelago in the North Atlantic, with records from five islands: Faial, Flores, Graciosa, Pico, and São Jorge. As a member of the genus Melanotus, it shares the characteristic click beetle morphology including an elongated body form and the prosternal process that enables the defensive "clicking" mechanism.
Melyrodes floridana
Florida Soft-winged Flower Beetle
Melyrodes floridana is a species of soft-winged flower beetle in the family Melyridae, endemic to Florida. The genus Melyrodes is small and poorly documented, with limited information available on its biology and ecology. This species appears to be rarely encountered, with minimal observational records.
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.
Mesamia divisa
Mesamia divisa is a species of leafhopper in the family Cicadellidae, described by DeLong and Hershberger in 1947. It belongs to the subfamily Deltocephalinae and tribe Platymetopiini. The species is known from multiple states in central and northern Mexico. Like other members of its family, it is presumed to feed on plant sap using piercing-sucking mouthparts.
Meta dolloff
Dolloff Cave Spider
Meta dolloff, commonly known as the Dolloff Cave Spider, is a rare spider species endemic to California. It belongs to the family Tetragnathidae, a group characterized by elongated bodies and long jaws. The species is considered among the rarest spiders in North America, with limited observations documented.
Metanotalia maderensis
Metanotalia maderensis is a species of parasitoid wasp in the family Encyrtidae, originally described by Walker in 1872 as Ectroma maderense. It is endemic to the Madeira archipelago in the North Atlantic Ocean. The genus Metanotalia is a small group within the Encyrtidae, a family known for their role as parasitoids of scale insects and other hemipteran pests. Specimens of this species are held in the University of California, Riverside (UCR) Encyrtidae collection, one of the largest collections of this family globally.
Metasiro sassafrasensis
mite harvestman
Metasiro sassafrasensis is a species of mite harvestman (suborder Cyphophthalmi) in the family Neogoveidae. It was described in 2014 by Clouse and Wheeler. The species is known from a single locality in Grady County, North America. Like other Cyphophthalmi, it is a small, eyeless harvestman adapted to cryptic habitats.
Metepeira pimungan
San Miguel Island Orbweaver
Metepeira pimungan is a species of orb-weaving spider in the family Araneidae, described by Piel in 2001. It is endemic to the United States, specifically known from San Miguel Island off the coast of California. As a member of the labyrinth spider genus Metepeira, it likely constructs the characteristic combination of an orb web with a tangled labyrinthine retreat structure. The species is poorly known, with limited published information beyond its original description.