Carnoidea

Identification to superfamily level relies on male genitalia characters, particularly the flexible, unsclerotized, microtrichose phallus, and exclinate uppermost fronto-orbital bristles. Family assignment requires examination of additional characters: Braulidae are recognized by their association with honey bees and reduced wing venation; Canacidae by their presence in wave-swept marine habitats with characteristic chaetotaxy; Chloropidae by their often yellowish coloration and reduced wing venation; Carnidae by small size and association with decaying matter. Inbiomyiidae are distinguished by their extremely shortened head morphology and unique genitalic structures. The superfamily is most readily separated from other acalyptrate superfamilies by the combination of head bristle orientation and male genitalia structure, though these characters require microscopic examination.

Members of Carnoidea are small flies, generally not exceeding a few millimeters in body length. Diagnostic features include: uppermost fronto-orbital bristle(s) of the head exclinate (directed outward); male phallus flexible, unsclerotized, simple, elongate, and covered with microtrichia. Family-level variation is substantial: Inbiomyiidae possess an extremely shortened head with nonfunctional ptilinum, reduced chaetotaxy, shortened first flagellomere with elongate dorsoapically inserted arista, proboscis with separate labellar lobes pointing in different directions, mid tibia lacking apicoventral bristle, and large, extremely flattened eggs.

Habitats vary extensively by family. Canacidae and Australimyzidae are primarily intertidal and seashore-associated, found on beaches, estuarine tidal flats, wave-swept rocks, and mangroves. Inbiomyiidae occur in primary lowland rain forest, often associated with decaying foliage of fallen trees. Carnidae occupy diverse terrestrial habitats including decaying plant matter, animal dung, carrion, and vertebrate nests. Milichiidae occur in general habitats with some species restricted to ant nests, bee nests, or bat dung in caves. Braulidae are exclusively associated with honey bee colonies.

Cosmopolitan distribution with family-level variation. Inbiomyiidae are Neotropical, ranging from Guatemala south to French Guiana and Bolivia. Australimyzidae are Australasian. Canacidae are primarily coastal and occur in marine intertidal zones worldwide. Carnidae, Chloropidae, and Milichiidae have broad distributions. The superfamily as a whole has been documented across all major biogeographic regions.

Feeding habits are family-specific and highly variable. Canacidae adults and larvae feed primarily on algae in the intertidal zone. Carnidae and Milichiidae are scavengers, feeding on decaying organic matter including plant material, dung, and carrion. Braulidae adults feed from bee mouthparts. Inbiomyiidae adults are microbial grazers, consuming fungal, algal, and bacterial material; their larvae are undescribed. Chloropidae larvae exhibit diverse habits: scavenging, herbivory in plant shoots and stems (possibly bacterial feeding), hematophagy on frogs, and predation on insect or spider eggs.

• Apis (honey bees) - associateBraulidae: larvae develop in beeswax, adults attach to bees and feed from mouthparts
• Formicidae (ants) - associateSome Milichiidae restricted to ant nests
• Chiroptera (bats) - associateSome Milichiidae restricted to bat dung in caves
• Anura (frogs) - parasiteSome Chloropidae larvae feed on frog blood

Life cycle details vary by family and are incompletely known for several groups. Braulidae larvae develop in beeswax within honey bee colonies. Canacidae and Australimyzidae larvae are believed to feed in intertidal zones and decaying plant matter respectively, though detailed developmental data are lacking. Inbiomyiidae larvae remain undescribed. Carnidae and Milichiidae larvae develop in decaying organic substrates. Chloropidae exhibit the most diverse larval ecology, with development in plant tissues, as predators, or as parasites.

Braulidae adults exhibit phoretic behavior, attaching to honey bees. Canacidae adults are active in wave-swept marine habitats. Carnidae and Milichiidae are attracted to decaying organic matter. Some Milichiidae and Chloropidae display kleptoparasitic or commensal behaviors at spider or insect predation sites. Inbiomyiidae adults are associated with decaying foliage in rain forest habitats.

Carnoidea occupies multiple ecological roles across its constituent families. Canacidae and Australimyzidae contribute to nutrient cycling in coastal and intertidal ecosystems through algal and detrital processing. Carnidae and Milichiidae function as decomposers in terrestrial systems. Braulidae represent commensals or mild pests of pollinators. Chloropidae include herbivores, predators, and parasites, contributing to plant tissue herbivory, arthropod egg predation, and vertebrate parasitism. Some Chloropidae are significant agricultural pests of cereal crops.

Chloropidae includes several economically important pest species, particularly frit flies that damage cereal crops including wheat, barley, and oats. Braulidae are minor pests of honey bee colonies, though their economic impact is generally considered limited. Carnidae occasionally occur in stored products and domestic environments associated with decaying organic matter. The superfamily otherwise has limited direct interaction with humans.

• EphydroideaBraulidae have been suggested by molecular analysis to be more closely related to Drosophilidae (Ephydroidea) than to other Carnoidea, challenging superfamily boundaries
• OpomyzoideaSome Carnoidea families have been historically associated with or confused with Opomyzoidea due to similar small size and reduced wing venation in acalyptrate flies

The monophyly of Carnoidea has been repeatedly questioned. Early synapomorphies proposed in 1989 were largely challenged, and subsequent molecular analyses suggest the superfamily may be polyphyletic. The tentative acceptance of monophyly based on male genitalia characters remains subject to ongoing phylogenetic investigation.

• Diptera
• Acalyptratae
• Schizophora
• small flies
• decomposers
• intertidal
• scavengers

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Inbiomyiidae (Diptera, Carnoidea)
• A catalog of the Milichiidae of Chile (Diptera: Carnoidea)
• A new family and genus of acalypterate flies from the Neotropical region, with a phylogenetic analysis of Carnoidea family relationships (Diptera, Schizophora)