Nearctic
Guides
Metacyrba punctata
Metacyrba punctata is a species of jumping spider in the family Salticidae. The species is distributed across a broad range from the southern United States through Middle America to Ecuador. As a member of Salticidae, it possesses the characteristic large anterior median eyes that provide acute vision for hunting. The genus Metacyrba comprises small to medium-sized jumping spiders, though specific morphological details for M. punctata remain limited in published sources.
Metanema
Metanema is a genus of moths in the family Geometridae, subfamily Ennominae. The genus was erected by Achille Guenée in 1857 (published 1858) and currently contains approximately 14 described species distributed primarily in the Americas. Species within this genus are part of the diverse geometrid moth fauna, commonly known as inchworm or geometer moths due to the characteristic looping locomotion of their larvae.
Metopoloba
Metopoloba is a genus of darkling beetles (family Tenebrionidae) described by Casey in 1907. The genus is endemic to the Nearctic region, with 244 observations recorded on iNaturalist. As a member of Tenebrionidae, it belongs to a large and diverse family of beetles primarily associated with arid and semi-arid environments. Species-level taxonomy within this genus remains poorly documented in public sources.
Metretopus borealis
Metretopus borealis is a mayfly species in the family Metretopodidae, originally described as Heptagenia borealis by Eaton in 1871. It is distributed across the Nearctic and Palearctic regions, with confirmed presence in North America. The species belongs to a small family of mayflies whose members are typically associated with cool, flowing waters.
Metrobates artus
Metrobates artus is a water strider species in the family Gerridae, first described by Anderson in 1932. It belongs to the subfamily Trepobatinae, a group of gerrids adapted to life on flowing water surfaces. The genus Metrobates is primarily Nearctic in distribution. This species has been recorded from both Middle America and North America.
Mexicomiris
Mexicomiris is a genus of plant bugs in the family Miridae, containing seven described species. The genus was established by Carvalho & Schaffner in 1974. Species are distributed in Mexico and the southern United States, with several species names suggesting associations with oak (Quercus). The genus is part of the diverse mirid fauna of the Nearctic and Neotropical regions.
Mexiweckelia hardeni
Mexiweckelia hardeni is a species of amphipod crustacean in the family Hadziidae, first described by Holsinger in 1992. The genus Mexiweckelia is part of a group of amphipods adapted to subterranean or aquatic habitats. As a member of Hadziidae, it likely inhabits groundwater or cave systems, though specific ecological details remain poorly documented. The species is known from limited collection records in the Nearctic region.
Mexoleon
Mexoleon is a genus of antlions (family Myrmeleontidae) containing at least two described species: M. mixtecus and M. papago. The genus was established by Stange in 1994. Like other antlions, adults are neuropteran insects with large, transparent wings, while larvae are predatory and construct pit traps in sandy substrates.
Mezira granulata
Mezira granulata is a species of flat bug in the family Aradidae, characterized by its dorsoventrally flattened body form. The species is distributed across the Caribbean, Central America, and North America. Like other members of Aradidae, it is associated with decaying wood and fungal habitats. The specific epithet 'granulata' refers to a granular or roughened body surface texture.
Micaria rossica
Micaria rossica is a ground spider in the family Gnaphosidae, first described by Thorell in 1875. It belongs to the infraorder Araneomorphae, the 'true spiders' characterized by modern respiratory and silk-producing systems. The species has a notably broad distribution spanning the Holarctic and extending into Central Asia.
Micraegialia pusilla
Micraegialia pusilla is a small scarab beetle in the subfamily Aegialiinae, first described by Horn in 1887. The species occurs in northern North America, with records from Alaska, Washington, Minnesota, North Dakota, and Canadian provinces including Alberta, British Columbia, and Manitoba. As a member of the tribe Aegialiini, it belongs to a group commonly known as sand-loving scarabs.
Micrargus
dwarf spiders
Micrargus is a genus of dwarf spiders (family Linyphiidae) described by Friedrich Dahl in 1886. The genus contains seventeen recognized species distributed across Europe, Asia, North America, and Africa. Several species form a distinct species group centered on M. herbigradus, characterized by specific male palpal and female epigynal structures. The genus exhibits considerable habitat flexibility, with species ranging from lowland forests to alpine meadows and caves.
Micrasema charonis
humbless casemaker caddisfly
Micrasema charonis is a species of caddisfly in the family Brachycentridae, described by Banks in 1914. It belongs to the group commonly known as humpless casemaker caddisflies, distinguishing it from other caddisfly families by its case construction behavior. The species is documented from North America.
Micrisotoma achromata
Micrisotoma achromata is a species of springtail in the family Isotomidae, described by P.F. Bellinger in 1952. It belongs to a genus characterized by small body size and reduced pigmentation. The species has been recorded across multiple continents including North America, Eurasia, and Malaysia, suggesting either a broad natural distribution or potential cryptic species complexity. Like other isotomids, it inhabits soil and leaf litter environments.
Microcentrus lynx
Microcentrus lynx is a treehopper species in the family Membracidae, subfamily Stegaspidinae, described by Ball in 1933. It belongs to the tribe Microcentrini, a group characterized by distinctive pronotal modifications. The species has been recorded from the southwestern United States (Arizona, Colorado) and several Mexican states (Durango, Hidalgo, Michoacán). Like other treehoppers, it possesses an enlarged pronotum that extends over the thorax, though specific morphological details for this species remain limited in published sources.
Microcentrus perditus
Microcentrus perditus is a treehopper species in the family Membracidae, subfamily Stegaspidinae. It is native to the Nearctic region, with confirmed records from Texas, USA. The species was described by Amyot and Audinet-Serville in 1843 and belongs to the tribe Microcentrini, which is characterized by distinctive pronotal modifications typical of this group of treehoppers.
Microcentrus solussidus
Microcentrus solussidus is a treehopper species described in 2004 from Texas. It belongs to the tribe Microcentrini, characterized by pronotal modifications that extend over the body. The genus Microcentrus is part of the subfamily Stegaspidinae, a group of treehoppers found in the Nearctic region. This species was described relatively recently compared to many congeners, reflecting ongoing taxonomic work in this morphologically diverse family.
Microcylloepus
Microcylloepus is a genus of riffle beetles (family Elmidae) established by Hinton in 1935. The genus contains approximately nine described species distributed primarily in the Americas, with records from the United States to Colombia. These beetles are aquatic and inhabit flowing water environments, particularly springs and spring-runs. One species, Microcylloepus pusillus, has been studied in detail at Comal Springs, Texas, where it coexists with the endangered beetle Heterelmis comalensis.
Microedus
Microedus is a genus of small rove beetles in the family Staphylinidae, subfamily Omaliinae, tribe Anthophagini. The genus was historically known only from North America but was expanded to the Palaearctic Region following taxonomic revision in 2022, which synonymized two Palaearctic genera (Altaiodromicus and Liophilydrodes) with Microedus. The genus currently contains 16 species: seven in the Nearctic Region and nine in the Palaearctic Region. Members of this genus belong to the Hygrogeus group of omaliine rove beetles.
Microedus austinianus
Nearctic rove beetle and type species of the genus Microedus. First illustration of mouthparts and aedeagus provided in 2022 taxonomic revision. One of seven Nearctic species in a genus now recognized as transcontinental.
Micromes
Micromes is a genus of darkling beetles in the family Tenebrionidae, described by Casey in 1907. The genus is native to the Nearctic region. As a member of Tenebrionidae, it belongs to a large and diverse family of beetles commonly associated with arid and semi-arid environments. Specific information about the species within this genus and their biology remains poorly documented.
Micropeplus neotomae
Micropeplus neotomae is a species of rove beetle in the subfamily Micropeplinae, described by Campbell in 1968. The species epithet 'neotomae' suggests an association with the rodent genus Neotoma (woodrats/packrats). It is known from California and Oregon in the western United States. As a member of the Staphylinidae, it possesses the characteristic short elytra that expose most of the abdomen.
Microphor
Microphor is a genus of small to very small flies in the family Dolichopodidae, subfamily Microphorinae. The genus contains at least 16 extant species distributed across the Palaearctic, Oriental, Nearctic, and potentially Neotropical realms. Females exhibit kleptoparasitic behavior, stealing tiny prey from spider webs. The genus is characterized by specific morphological traits including eyes without ommatrichia, a scutellum with three or more pairs of setae, and distinctive wing venation.
Microvelia albonotata
Microvelia albonotata is a small water strider species in the family Veliidae, first described by Champion in 1898. It belongs to a genus of minute semiaquatic bugs commonly found on the water surface film. The species has been documented across a broad Neotropical and Nearctic range including the Caribbean, Middle America, North America, and South America. Like other Microvelia species, it is adapted to life at the air-water interface.
Mimobarathra
Mimobarathra is a genus of noctuid moths erected by William Barnes and James Halliday McDunnough in 1915. The genus is monotypic, containing only the single species Mimobarathra antonito, which was described by Barnes in 1907. It is endemic to Arizona in the southwestern United States. The genus belongs to the tribe Eriopygini within the subfamily Noctuinae.
Mimoceps insignis
Mimoceps insignis is a small plant bug in the family Miridae, first described by Uhler in 1890. The species is characterized by its distinctive coloration and moderate size among mirid bugs. It occurs in grasslands and open field habitats across parts of North America.
Mimophobetron
Mimophobetron is a monotypic moth genus in the family Crambidae, established by Eugene G. Munroe in 1950. The genus contains a single species, Mimophobetron pyropsalis, originally described by George Hampson in 1904. It is found in parts of Central America, the Caribbean, and the southeastern United States.
Ministrymon
ministreaks
Ministrymon is a genus of small butterflies in the family Lycaenidae, commonly known as ministreaks. The genus was established by Clench in 1961 and contains approximately 20 described species distributed across the Nearctic and Neotropical realms. Species are diminutive, typically about the size of a thumbnail. The genus includes Ministrymon janevicroy (Vicroy's Ministreak), a recently described species from Texas distinguished by its distinctive olive-green eyes.
Ministrymon azia
Gray Ministreak
Ministrymon azia, commonly known as the gray ministreak, is a small butterfly in the family Lycaenidae. It ranges from the southern United States through Central America to southern Brazil, Paraguay, and Argentina. The species occupies diverse lowland habitats including deserts and rainforests. Adults are active year-round in tropical regions and from March to September in Florida and Texas.
Mischocyttarus
Long-waisted Paper Wasps
Mischocyttarus is the largest genus of social wasps, containing over 260 species primarily distributed in the Neotropics. It is the sole member of the tribe Mischocyttarini, distinguished from related tribes by asymmetrical tarsal lobes. These wasps construct simple, single-comb paper nests and exhibit greater social and reproductive flexibility than the related genus Polistes. A few species extend into the Nearctic region, including three in the United States and southwest Canada.
Mocis disseverans
Yellow Mocis Moth
Mocis disseverans, commonly known as the Yellow Mocis Moth, is a nocturnal moth in the family Erebidae. It occurs in the Caribbean and the southern United States, with documented populations in Florida, Texas, and Mississippi. The species has a wingspan of approximately 40 mm. Like other members of the genus Mocis, it is likely associated with grassland and open habitats.
Momar fumidus
Momar fumidus 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. The species has been documented in the southwestern United States and northwestern Mexico. Like other achilid planthoppers, it is associated with fungal hosts.
Mompha definitella
A small moth in the family Momphidae, first described by Zeller in 1873. This species is known from limited observations in western Canada. Like other Momphidae, it likely has narrow wings and a compact body form. The specific epithet 'definitella' refers to its original description under the genus Laverna.
Monomacra
Monomacra is a genus of flea beetles in the family Chrysomelidae, tribe Alticini. The genus comprises approximately 17 to 120 described species, with sources varying on the exact number. Species are distributed across the Nearctic and Neotropical regions, including North America, Central America, and tropical South America. As members of the Alticini, they possess the enlarged hind femora characteristic of flea beetles, enabling jumping locomotion.
Multareoides bifurcatus
Multareoides bifurcatus is a treehopper species (Membracidae) described by Cook in 1953. The species is characterized by its bifurcated pronotal structure, as suggested by its specific epithet. It belongs to the tribe Centrodontini within the subfamily Centrotinae. The genus Multareoides is a small group of treehoppers with limited published biological information.
Mycetaeidae
Mycetaeidae is a small family of beetles in the superfamily Coccinelloidea, established as distinct from Endomychidae based on morphological and molecular evidence. The family contains three genera: Agaricophilus (one species, Europe), Mycetaea (two species, North America, Europe, South Africa, and Canary Islands), and Afromycetaea (seven species, sub-Saharan Africa and Madagascar). The family is confirmed as monophyletic and sister to Cerasommatidiidae. Members of the genus Mycetaea are known to be mycophagous, feeding on molds.
Mycotrupes cartwrighti
Cartwright's Mycotrupes
Mycotrupes cartwrighti is an earth-boring scarab beetle in the family Geotrupidae, described by Olson and Hubbell in 1954. The species is endemic to the southeastern United States, with confirmed records from Florida and Georgia. Like other members of its genus, it is a fossorial beetle adapted to burrowing in sandy soils. The common name honors American entomologist John B. Cartwright.
Myllaena
Myllaena is a genus of rove beetles in the family Staphylinidae, subfamily Aleocharinae, and tribe Myllaenini. The genus contains more than 60 described species distributed across the Nearctic and Palearctic regions. A taxonomic revision of Nearctic species recognized 20 species arranged into four species groups: Cuneata, Insomnis, Potawatomi, and Seminole.
Myolepta nigra
Black Pegleg
Myolepta nigra, commonly known as the Black Pegleg, is a syrphid fly species found in the eastern and central United States and eastern Canada. Adults are flower-visiting hoverflies that feed on nectar and pollen. The larvae develop in rot holes of deciduous trees, making this species dependent on mature forest habitats with suitable tree cavities. It is considered uncommon throughout its range.
Myrmecoblatta wheeleri
Wheeler's Ant Cockroach
Myrmecoblatta wheeleri is a small, myrmecophilous cockroach species known for its obligate association with ant colonies. First described by Hebard in 1917, this species inhabits the nest chambers of host ants, where it has been observed in Costa Rica, Guatemala, and Florida. The species represents one of the few documented cases of true myrmecophily in cockroaches, having evolved specialized adaptations for life within ant societies. Its common name honors the American entomologist William Morton Wheeler, who conducted pioneering studies on ant ecology and myrmecophilous organisms.
Myrmecotypus lineatus
Myrmecotypus lineatus is a species of true spider in the family Corinnidae, subfamily Castianeirinae. It is the only species in the genus Myrmecotypus with a documented occurrence in the United States, making its distribution atypical compared to congeners which are otherwise restricted to the Neotropical region (Mexico to Panamá). The species was described by Emerton in 1909. Very few observations of this spider exist in public databases.
Myrmoecia lauta
Myrmoecia lauta is a rove beetle in the family Staphylinidae, subfamily Aleocharinae. The species was described by Casey in 1893. It belongs to the tribe Lomechusini, a group known for myrmecophilous (ant-associated) associations. Records indicate presence in northeastern North America with some questionable reports from China.
Myrmosula
Myrmosula is a genus of small parasitic wasps in the family Myrmosidae (sometimes historically placed in Mutillidae). These insects are part of a poorly studied group of velvet ant relatives, with winged males and wingless females. The genus was established by Bradley in 1917 and remains taxonomically challenging due to limited specimen availability and morphological convergence with other myrmosid genera.
Mystacides alafimbriatus
long-horned caddisfly
Mystacides alafimbriatus is a species of long-horned caddisfly in the family Leptoceridae, described by Hill-Griffin in 1912. It is one of approximately 20 species in the genus Mystacides. The species is known from the Nearctic region, with records from North America. As with other Leptoceridae, adults are characterized by antennae that are notably longer than the body.
Myxosargus
soldier flies
Myxosargus is a genus of soldier flies in the family Stratiomyidae, containing approximately 13-15 described species distributed primarily in the Americas. The genus was established by Brauer in 1882 and includes species ranging from the southwestern United States through Central America to South America. Most species were described in the early-to-mid 20th century, with several added by Maurice James in 1979.
Nannocyrtopogon
Nannocyrtopogon is a genus of robber flies (family Asilidae) comprising at least 20 described species. Members of this genus are aerial predators that capture other insects in flight. The genus was established by Wilcox and Martin in 1936 and is classified within the subfamily Brachyrhopalinae and tribe Ceraturgini. These flies are found in the Nearctic and Neotropical regions.
Nanularia pygmaea
Nanularia pygmaea is a small metallic wood-boring beetle in the family Buprestidae. The species was described by Knull in 1941 and is known from North America. It belongs to the Nanularia genus group within the subfamily Chrysochroinae.
Naphrys acerba
Naphrys acerba is a jumping spider species in the family Salticidae, distributed across the United States and Mexico. It was first described by the Peckhams in 1909 and represents one of the more southerly distributed members of the genus Naphrys. The species has been documented with precise locality records in northeastern Mexican states including Nuevo León and Tamaulipas, extending the known range of the genus beyond the Nearctic region.
Nascia
Nascia is a genus of grass moths in the family Crambidae, subfamily Pyraustinae. The genus was established by John Curtis in 1835 and contains three recognized species distributed across parts of Europe and North America. These are small to medium-sized moths associated with grassland habitats.
Neacreotrichus
Neacreotrichus is a genus of bee flies (Bombyliidae) comprising approximately 13 described species. The genus was established by Theodore Dru Alison Cockerell in 1917. Species are found in the southwestern United States and Mexico. Members are small-bodied bee flies that have been documented in arid and semi-arid environments.