Acalyptrate
Guides
Afrocamilla
Afrocamilla is a genus of small flies in the family Camillidae, established by Barraclough in 1992. The genus is endemic to Africa, distinguishing it from the primarily Australasian distribution of related camillid genera. As part of the poorly known family Camillidae, Afrocamilla species are minute acalyptrate flies associated with decaying organic matter. The family Camillidae is placed in the superfamily Opomyzoidea within the large suborder Brachycera.
Anthomyza variegata
Anthomyza variegata is a species of small fly in the family Anthomyzidae, a family of acalyptrate Diptera. The species was originally described by Loew in 1863 under the basionym Anthophilina variegata. Anthomyzid flies are generally associated with decaying plant matter and fungi. The specific epithet 'variegata' suggests variable or patterned coloration, though detailed morphological descriptions are sparse in available literature. The family Anthomyzidae is a small group of flies with limited ecological documentation.
Asteiidae
Fine Flies
Asteiidae is a small family of acalyptrate flies comprising approximately 130 species in 10 genera worldwide. Adults are minute to small (1–3 mm), delicate flies with thin bodies and relatively long, transparent wings. The family is rarely collected, likely due to their small size and inconspicuous habits. Most species are found in forested habitats, with adults often observed on flowers, low vegetation, and fungi.
Aulacigaster mcalpinei
Aulacigaster mcalpinei is a small fly species in the family Aulacigastridae, described by Mathis and Freidberg in 1994. The genus Aulacigaster comprises flies associated with sap flows and wounded trees. Aulacigastridae is a small family of acalyptrate Diptera with limited documented natural history.
Braulidae
bee lice, bee louse
Braulidae is a family of highly modified, wingless flies (Diptera) comprising two genera—Braula and Megabraula—with approximately seven to eight described species. These insects are obligate associates of honey bees (Apis spp.), exhibiting a commensal to kleptoparasitic lifestyle. Adults are minute (1.6–3 mm), reddish-brown, and superficially resemble mites or lice due to their reduced morphology. They attach to bee bodies using specialized claw structures and feed by intercepting food during trophallaxis. The family has undergone extensive morphological simplification associated with this specialized host relationship.
Chamaemyiidae
silver flies, aphid flies
Chamaemyiidae is a small family of acalyptrate flies comprising fewer than 200 described species worldwide. Adults are minute (1–5 mm), typically greyish, and morphologically characterized by reduced bristling. Larvae are active predators of Sternorrhyncha, particularly aphids, adelgids, and scale insects, making several species valuable biological control agents. The family has been deployed in classical biological control programs targeting invasive pests such as the hemlock woolly adelgid and pink hibiscus mealybug. Fossil records are sparse but extend to the Eocene.
Chyromyidae
Golden Flies
Chyromyidae are small to minute acalyptrate flies (Diptera: Heleomyzoidea) commonly known as Golden Flies. The family contains approximately 150 described species worldwide, currently classified into four genera, though ongoing research suggests additional generic diversity exists. Adults are characterized by pale yellow body coloration and striking iridescent eyes. The family's biology remains poorly understood, with no complete life histories documented for any species.
Clusiidae
druid flies
A family of small acalyptrate flies (approximately 3.5 mm) commonly known as druid flies. The family comprises 636 species in 14 genera across three subfamilies, with highest diversity in tropical regions. Adults are typically found on tree trunks, while larvae inhabit decaying wood. Several genera exhibit lekking behavior and territorial defense by males.
Diopsoidea
Diopsoidea is a small but diverse superfamily of acalyptrate muscoid flies with cosmopolitan distribution, particularly abundant in tropical regions. The group has experienced taxonomic revision, with Strongylophthalmyiidae and Tanypezidae now placed in Nerioidea. The superfamily includes families such as Diopsidae (stalk-eyed flies), Psilidae, and Syringogastridae.
Glyphidops
cactus flies
Glyphidops is a genus of cactus flies in the family Neriidae, established by Enderlein in 1922. These flies belong to the acalyptrate schizophoran group of Diptera. The genus is characterized by specific morphological features that distinguish it from related genera within Neriidae, particularly in antennal and leg structure. Species-level identification within Glyphidops requires examination of characters such as forecoxae coloration.
Heterocheila
half-bridge flies
Heterocheila is a genus of acalyptrate flies comprising the monotypic family Heterocheilidae. The genus contains two described species: Heterocheila buccata (Palearctic distribution across North America and Eurasia) and Heterocheila hannai (restricted to the northeastern USA and Pacific Northwest coasts). These flies are specialized inhabitants of temperate seashores, where adults and larvae feed on stranded kelp in the wrack zone.
Lauxaniidae
Lauxaniid Flies
Lauxaniidae is a family of acalyptrate flies comprising approximately 1800 described species across 126 genera. Adults are small (2–7 mm), often with large, brightly colored compound eyes and variegated wing patterns. The family has a cosmopolitan distribution with highest diversity in tropical Asia and the Americas; species richness declines markedly toward temperate regions. Adults are typically sedentary, associated with shaded, humid forest environments where they feed on leaf-surface fungi. Larvae are primarily saprophagous, developing in decaying plant matter, leaf litter, rotting wood, and bird nests.
Lonchaeidae
Lance Flies
Lonchaeidae, commonly known as lance flies, is a family of acalyptrate dipteran flies comprising approximately 611 described species across 10 genera. These small, robust flies are characterized by blue-black or metallic bodies and are predominantly associated with wooded habitats worldwide. The family exhibits diverse larval ecology, with most species being phytophagous on damaged plant tissues, though coprophagous, mycophagous, saprophagous, and predatory habits are also documented. Several species are significant agricultural pests, particularly of figs, cassava, and conifer seeds, while others develop in bark beetle tunnels, decaying wood, or fungal fruiting bodies.
Micropeza compar
Micropeza compar is a species of stilt-legged fly (family Micropezidae) described by Cresson in 1938. The genus Micropeza is characterized by extremely long, slender legs and a distinctive elongated body form. Members of this family are commonly known as stilt-legged flies or thread-legged flies due to their remarkable limb proportions. M. compar is one of numerous species within this diverse genus of acalyptrate flies.
Micropezidae
stilt-legged flies
Micropezidae is a family of acalyptrate muscoid flies comprising approximately 500 species in 50 genera and five subfamilies. Commonly called stilt-legged flies, they are distinguished by extraordinarily elongated middle and hind legs, with markedly smaller fore legs. Adults range from 3–16 mm and exhibit remarkable mimicry of ants, wasps, and ichneumonid wasps. The family is most diverse in tropical and subtropical regions, particularly the Neotropics, and is absent from New Zealand and Macquarie Island. Larval biology remains poorly known, with development occurring in decaying vegetation, manure, fungi, and in some species, living plant roots.
Neossos tombstonensis
Neossos tombstonensis is a recently described species of small acalyptrate fly in the family Heleomyzidae, endemic to the Yukon Territory, Canada. It is the fourth described Nearctic species of the rarely collected genus Neossos. The species is extremely small (1.9–2.1 mm) and was described from only two specimens collected by sweeping vegetation in subarctic habitats. Despite the collection method, the species is hypothesized to be an obligate associate of bird nests based on consistent habits documented across other members of the genus.
Opomyzidae
Grass Flies
Opomyzidae is a family of acalyptrate Diptera commonly known as grass flies. Adults are small, slender flies ranging from yellow to brown, reddish, or black. Larvae are stem-borers in grasses (Poaceae), including cereal crops, with some species causing significant agricultural damage. The family is distributed primarily in temperate regions of the boreal hemisphere, with an autumn-spring life cycle adapted to grass phenology.
Pallopteridae
flutter-wing flies, trembling-wing flies, waving-wing flies
Pallopteridae is a small family of acalyptrate flies comprising approximately 70 species across 15 genera, distributed primarily in temperate regions of both Northern and Southern Hemispheres. Adults are recognized by their characteristic wing vibration behavior, which produces the common names flutter-wing, trembling-wing, or waving-wing flies. The family exhibits diverse larval feeding strategies including saprophagy, phytophagy, and occasional zoophagy, with larvae developing in flowerheads, stems, and other plant tissues.
Periscelididae
Dwarf Flies
Periscelididae is a family of small acalyptrate flies commonly known as Dwarf Flies. Adults are typically 3–4 mm in length with a distinctly broad head, broad bulging cheeks, and characteristic bristle patterns on the head and thorax. The family comprises approximately 12 genera in two subfamilies (Periscelidinae and Stenomicrinae), with species distributed across the Palaearctic, Nearctic, and Neotropical regions. At least some species develop in phytotelmata—water-holding plant structures such as those in Araceae.
Platystomatidae
Signal Flies
Platystomatidae, commonly known as signal flies, is a family of acalyptrate Diptera in the superfamily Tephritoidea. The family comprises approximately 1200 species in 127 genera, with highest diversity in tropical regions, particularly the Australasian and Afrotropical realms. Adults are characterized by distinctive wing patterns and often metallic coloration. Many species exhibit elaborate sexual dimorphisms, including extreme head modifications in males used in agonistic interactions. The family is notable for convergent evolution of eyestalks with Diopsidae, though developed through different morphological pathways.
Ropalomeridae
Ropalomeridae is a small family of acalyptrate flies comprising approximately 30 species across 9 genera. The family is predominantly Neotropical in distribution. Members are robust flies measuring 6–12 mm in length, characterized by conspicuously enlarged hind femora and often laterally flattened, broadened hind tibiae. The biology of most species remains poorly known, though they have been associated with rotting wood.
Sciomyzidae
Marsh Flies, Snail-killing Flies
Sciomyzidae is a family of acalyptrate flies in the order Diptera, commonly known as marsh flies or snail-killing flies. The family contains 543 extant species in 63 genera with worldwide distribution, though poorly represented in the Australasian and Oceanian realms. Adults are small to medium-sized flies (2–14 mm) typically found in wet habitats. The larvae are predominantly predators or parasites of freshwater and terrestrial mollusks, particularly snails and slugs, making this family notable for its specialized feeding biology.
Sciomyzoidea
Kelp, Marsh, Thick-headed Flies and Allies
Sciomyzoidea is a superfamily of acalyptrate flies (Diptera: Acalyptratae) comprising at least 11 families, including the well-known Sciomyzidae (snail-killing or marsh flies), Sepsidae (scavenger flies), and Coelopidae (seaweed flies). The superfamily exhibits diverse ecological specializations, with some families associated with marine or coastal habitats and others with freshwater or terrestrial environments. The family Sciomyzidae is particularly notable for its larval predation and parasitism on gastropods.
Senopterina varia
Senopterina varia is a species of signal fly in the family Platystomatidae, first described by Coquillett in 1900. Signal flies are known for their distinctive wing patterns and courtship behaviors involving wing signaling. The genus Senopterina is part of a diverse family of acalyptrate flies found primarily in tropical and subtropical regions.
Tanypeza longimana
Tanypeza longimana is a species of true fly in the family Tanypezidae, a small family of acalyptrate flies. The species was described by Fallén in 1820 and occurs in Europe. Members of this family are characterized by elongated bodies and long legs. The specific epithet "longimana" refers to the long forelegs typical of this species.
Tanypeza picticornis
Tanypeza picticornis is a species of true fly in the family Tanypezidae, described by Knab and Shannon in 1916. The family Tanypezidae is a small group of acalyptrate flies within the order Diptera. Very little is known about the biology or ecology of this species. It is known from a limited number of observations and specimens.
Tanypezidae
Stretched-foot Flies
Tanypezidae is a small family of acalyptrate Diptera containing 28 species in two genera. The family is primarily New World in distribution, with Tanypeza (2 species) occurring in North America and the Palearctic, and Neotanypeza (26 species) restricted to the Neotropics. Species are characterized by their relatively large size, semispherical heads, stout bodies, and notably long, thin legs that give the family its common name. The biology of most species remains poorly known.
Tethininae
Beach Flies
Tethininae is a subfamily of tiny acalyptrate flies within Canacidae, comprising over 115 species across seven genera. Formerly treated as family Tethinidae, the group is now recognized as paraphyletic. These drab-colored flies are strongly associated with maritime habitats, particularly intertidal zones and rotting seaweed accumulations. Despite their global distribution across all zoogeographic regions, many tropical species remain poorly documented.
Traginops irroratus
Traginops irroratus is a species of fly in the family Odiniidae, described by Coquillett in 1900. The genus Traginops belongs to the subfamily Traginopinae, one of the more distinctive lineages within this small family of acalyptrate Diptera. Odiniid flies are generally associated with decomposing wood and sap flows, though specific natural history details for this species remain poorly documented.