Mydidae
Guides
Asiloidea
asiloid flies
Asiloidea is a large superfamily of true flies (Diptera: Brachycera) with cosmopolitan distribution. It comprises approximately 11 families including the well-known Asilidae (robber/assassin flies), Bombyliidae (bee flies), Therevidae (stiletto flies), Mydidae (mydas flies), and Scenopinidae (window flies). Adult morphology is characterized by antennae with no more than 4 flagellomeres, leg empodium usually setiform or absent, and wing venation featuring an elongate cell cup with vein CuA2 ending freely or meeting A1 near the wing margin. Larval synapomorphies include posterior spiracles arising dorsally from the penultimate abdominal segment and, in most families except Bombyliidae and Hilarimorphidae, a modified cranium forming a hinged metacephalic rod.
DipteraBrachyceraAsiloidearobber-fliesbee-fliesstiletto-fliesmydas-flieswindow-fliescosmopolitanarid-habitatspredatory-larvaeflower-visitorsparasitoidsbiological-controlAsilidaeBombyliidaeTherevidaeMydidaeScenopinidaeApioceridaeApsilocephalidaeApystomyiidaeEvocoidaeHilarimorphidaeMythicomyiidaeProtapioceridaephylogenysystematicsvenomouspredatorymystaxmetacephalic-roddichopticholopticJurassicCretaceoustherevoid-cladeNamib-DesertCanary-IslandsSaudi-ArabiaDominicaChileGermanyfossilcybertaxonomyopen-accessZooKeysBohart-MuseumWorld-Robber-Fly-DayLeptomydinae
Mydas flies
Leptomydinae is a subfamily of mydas flies (family Mydidae) containing at least 6 genera and more than 50 described species. Members are primarily distributed in the Northern Hemisphere. The subfamily includes the genera Eremomidas, Hessemydas, Leptomydas, Nemomydas, Plyomydas, and Pseudonomoneura. Leptomydas, the type genus, was established by Gerstaecker in 1868.
Messiasia
Messiasia is a genus of mydas flies (family Mydidae) established by Andretta in 1951. The genus contains 16 described species distributed primarily in the Americas, with species known from the western United States, Central America, and South America. These flies are among the largest in Diptera and are characterized by their elongate bodies and wasp-like appearance.
Mydas
Mydas flies
Mydas is a genus of flies in the family Mydidae, established by Fabricius in 1794. These are among the largest flies in North America, with some species reaching substantial body lengths. The genus is characterized by elongate clubbed antennae and wasp-mimicking coloration, typically featuring black bodies with orange or red markings. Mydas flies are often mistaken for large wasps or robber flies by observers due to their impressive size and similar appearance to hymenopteran mimics.
Mydas clavatus
Clubbed Mydas Fly
Mydas clavatus is a large, striking mydas fly native to temperate eastern North America. Adults are notable Batesian mimics of spider wasps, displaying bold behavior enabled by their wasp-like appearance. The species is distinguished by a prominent orange to red abdominal marking and clubbed antennae—a trait shared across the genus. Adults are active in mid-summer and have been documented visiting diverse flowering plants for nectar.
Batesian-mimicrywasp-mimicpollinatorwoodboring-predatorMydidaeDipteraeastern-North-Americamid-summernectar-feederscarab-beetle-predatorclubbed-antennaeorange-abdominal-markingspider-wasp-mimicharmlessconspicuousbold-behaviormock-stinging-displayheart-rot-habitatOsmoderma-predatorflowering-plant-visitorlarge-flyglabrate-bodytemperate-forestmeadowgarden-visitordeciduous-woodlandMydas floridensis
Mydas floridensis is a species of mydas fly (family Mydidae) described in 1989. The genus Mydas contains some of the largest flies in North America. Members of this family are often Batesian mimics of spider wasps (Pompilidae), displaying bold black and orange or red coloration that allows them to fly conspicuously in open habitats. The specific epithet 'floridensis' indicates a type locality or primary distribution in Florida.
Mydas fulvifrons
Mydas fulvifrons is a species of mydas fly (family Mydidae), a group of large, wasp-mimicking flies related to robber flies. The genus Mydas contains some of the largest flies in North America. Like other mydas flies, adults are presumed to be nectar feeders, while larvae are believed to be predators of woodboring beetle larvae. The specific epithet 'fulvifrons' refers to the tawny or yellowish-brown frontal region of the head.
Mydas tibialis
Golden-legged Mydas Fly, golden legged mydas fly
Mydas tibialis, commonly known as the golden-legged mydas fly, is a large, striking mydas fly in the family Mydidae. The species is notable for its impressive size and distinctive golden-orange coloration on the legs, from which its common name derives. It occurs in North America, where adults have been observed visiting flowers, particularly those of Eryngium yuccifolium (rattlesnake master). The family Mydidae contains some of the largest flies in North America, and M. tibialis exemplifies this characteristic with its robust build.
Mydas xanthopterus
Mydas xanthopterus is a species of mydas fly in the family Mydidae. It occurs in North America, specifically in Mexico and the United States. The species is notable for its resemblance to red-winged Pepsis spider wasps, suggesting possible Batesian mimicry. It occurs in sympatry with Pepsis grossa, a large spider wasp species.
Mydinae
mydas flies
Mydinae is a subfamily of mydas flies within the family Mydidae, comprising approximately 12 genera and over 120 described species. The subfamily includes four tribes: Dolichogastrini, Messiasiini, Mydini, and Phyllomydini. Members of this subfamily are found primarily in the Neotropical region, with some genera exhibiting restricted geographic distributions. The genus Mapinguari, previously considered monotypic and rare, has been shown to have broader distribution than previously known.
Nemomydas
mydas flies
Nemomydas is a genus of large mydas flies (Diptera: Mydidae) comprising at least 23 described species distributed primarily in the Americas, with one species (N. gruenbergi) recorded from East Asia. The genus was established by Curran in 1934. Species exhibit considerable diversity in distribution, ranging from the southwestern United States through Central America to the Caribbean and South America.
Nemomydas brachyrhynchus
Nemomydas brachyrhynchus is a species of mydas fly in the family Mydidae, a group of large, robust flies known for their striking appearance and relatively uncommon occurrence. The species was described by Osten Sacken in 1886 and was originally placed in the genus Leptomidas. It is known from Mexico, though specific details about its biology remain poorly documented. Like other mydas flies, it likely has a complex life cycle involving soil-dwelling larval stages.
Nemomydas desideratus
Nemomydas desideratus is a species of mydas fly in the family Mydidae, described by Johnson in 1912. Members of this genus are among the largest flies in North America. The species is known from a small number of observations, suggesting it may be uncommon or have restricted habitat requirements. Mydidae are generally associated with arid and semi-arid environments.
Nemomydas melanopogon
Nemomydas melanopogon is a species of mydas fly in the family Mydidae, a group of large, predatory flies. It is endemic to Florida scrub habitat, a rare and threatened ecosystem type. The species was described by Steyskal in 1956. Like other mydas flies, it likely has a long larval development period in sandy soils.
Nemomydas venosus
Nemomydas venosus is a species of mydas fly (family Mydidae) described by Loew in 1866. The species is known from the United States. Mydas flies are among the largest flies in North America, though specific details for this species remain limited in published literature.
Opomydas limbatus
Opomydas limbatus is a species of mydas fly in the family Mydidae. Mydas flies are among the largest flies in North America and are characterized by their elongate bodies and wasp-mimicking appearance. This species occurs in the southwestern United States and Mexico. Like other mydas flies, adults are likely nectar feeders at flowers.
Opomydas townsendi
Opomydas townsendi is a species of mydas fly (family Mydidae), a group of large, predatory flies known for their elongated bodies and distinctive wing venation. The species was originally described as Ectyphus townsendi by Williston in 1898 and later transferred to the genus Opomydas. It is endemic to New Mexico, where it inhabits arid and semi-arid environments. Like other mydas flies, adults are likely predatory or nectar-feeding, though specific behavioral details remain poorly documented.
Phyllomydas
Phyllomydas is a genus of mydas flies (family Mydidae) established by Bigot in 1880. The genus contains seven described species distributed primarily in the Neotropical region. Members of this genus are among the larger dipterans, though specific ecological and biological details remain poorly documented in scientific literature.
Phyllomydas bruesii
Phyllomydas bruesii is a species of mydas fly in the family Mydidae, described by Johnson in 1926. The species is known from a small number of observations and limited published records. Like other members of the genus Phyllomydas, it is a large-bodied fly with distinctive morphology characteristic of the Mydidae family.
Phyllomydas parvulus
Phyllomydas parvulus is a species of mydas fly (family Mydidae) in the order Diptera. The species was originally described as Midas parvulus by Westwood in 1841 before being transferred to the genus Phyllomydas. It is known from Florida. Mydas flies are generally among the largest flies in North America, though specific size information for this species is not documented in available sources.
Pseudonomoneura
Pseudonomoneura is a genus of mydas flies (family Mydidae) comprising seven described species distributed in western North America, particularly in arid and semi-arid regions of the southwestern United States and northwestern Mexico. The genus was established by Bequaert in 1961 to accommodate species previously placed in related genera. Adults are generally robust, moderately sized flies with distinctive wing venation characteristic of the family.
Rhaphiomidas
flower-loving flies
Rhaphiomidas is a genus of mydid flies comprising fewer than 30 species and subspecies restricted to desert regions of the southwestern United States and northwestern Mexico. Adults are active for brief periods in spring or fall, with multiple species in the same dune system often separated by seasonal timing. Several taxa are critically endangered due to habitat loss from development and recreational disturbance.
Rhaphiomidas acton
Rhaphiomidas acton is a species of mydas fly (family Mydidae) found in southern California. It is one of three recognized species in the genus Rhaphiomidas. The species comprises three subspecies: R. a. acton, R. a. maculatus, and R. a. maehleri. Members of this genus are among the largest flies in North America and are of conservation concern due to habitat loss.
Rhaphiomidas hasbroucki
Rhaphiomidas hasbroucki is a species of mydas fly described by Cazier in 1985. It belongs to the family Mydidae, a group of large, robust flies often mistaken for wasps. The genus Rhaphiomidas is restricted to western North America and includes several species of conservation concern. This species is one of the lesser-known members of the genus with limited published biological data.
Rhaphiomidas terminatus
flower-loving fly
Rhaphiomidas terminatus is a species of mydas fly endemic to California. It belongs to the family Mydidae, a group of large, predatory or nectar-feeding flies. The species is commonly known as the flower-loving fly, reflecting its association with flowers. It is among the least-documented members of a poorly studied family in North America.
Stratiomydas
Stratiomydas is a genus of mydas flies (family Mydidae) established in 1989. The genus contains four described species distributed in Mexico, with records from Colima and Nayarit states. Species in this genus were previously classified under other genera before being separated based on morphological characteristics. Like other mydid flies, members are likely large-bodied and robust, though specific ecological data remain limited.