Psychodomorpha

Psychodomorpha is distinguished from other nematoceran infraorders by wing venation patterns and larval morphology. Adults typically possess broad, hairy wings held roof-like over the body; Psychodidae species often appear moth-like due to dense wing scaling. Blephariceridae have distinctive reduced mouthparts and specialized larval attachment organs. Tanyderidae are larger and more elongate with relatively simple wing venation. Scatopsoidea families are minute with reduced wing venation and short antennae compared to Psychodidae.

Larval habitats vary considerably across constituent families. Psychodidae larvae occur in moist organic matter including decaying vegetation, sewage, and aquatic margins; some species inhabit caves. Blephariceridae larvae are specialized for torrential mountain streams, using sucking discs to attach to rocks in fast-flowing water. Tanyderidae larvae have been found in moist forest soils and decaying wood. Scatopsoidea larvae inhabit decaying organic matter, fungi, and dung.

Cosmopolitan distribution with family-level variation. Psychodidae are worldwide in distribution. Blephariceridae are primarily found in mountainous regions of the Northern Hemisphere and parts of the Southern Hemisphere including South America and New Zealand. Tanyderidae have disjunct distributions in South America, Australia, and New Zealand. Scatopsoidea are widespread but poorly documented in many regions.

Complete metamorphosis with egg, larval, pupal, and adult stages. Larval development is aquatic or semi-aquatic for most families, with duration varying by habitat conditions. Blephariceridae have specialized larval stages adapted to torrential stream environments. Pupation occurs in or near the larval habitat; adults are generally short-lived and do not feed extensively.

Adults are generally weak fliers with crepuscular or nocturnal activity patterns. Many Psychodidae are attracted to light. Blephariceridae adults are rarely encountered, reflecting their brief adult lifespan and specialized habitat requirements. Mating behavior is poorly documented for most families.

Larvae contribute to decomposition and nutrient cycling in aquatic and terrestrial ecosystems. Blephariceridae larvae serve as bioindicators of high-quality, oxygen-rich stream environments. Some Psychodidae species are medically significant as vectors of leishmaniasis (Phlebotominae subfamily).

Certain Psychodidae (sand flies, genus Phlebotomus and related genera) are vectors of Leishmania parasites causing leishmaniasis in humans and animals. Moth flies (Psychodidae) are common nuisance pests in bathrooms and drains. The group otherwise has minimal direct economic impact.

• CulicomorphaBoth are nematoceran infraorders with aquatic larvae, but Culicomorpha (mosquitoes, midges, black flies) have scaled wings in only specific families, distinct larval mouthpart structures, and generally more slender adult bodies with longer legs relative to body size.
• BibionomorphaAnother nematoceran infraorder with broad wings, but Bibionomorpha typically have shorter, stouter antennae and larvae that are primarily terrestrial or in decaying wood rather than the specialized aquatic habitats of many Psychodomorpha.

The name is sometimes misspelled as 'Psychomorpha,' which is actually a genus of noctuid moths, not a dipteran taxon.

• nematocera
• flies
• aquatic larvae
• medical entomology
• bioindicators

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Beyond the Valdivian Forest: expanding the distribution of the vulnerable Tanyderus pictus (Diptera: Psychodomorpha: Tanyderidae) to the endangered Maulino Forest ecosystem