Hydrobiosidae

Hydrobiosidae can be distinguished from other Rhyacophiloidea families by genitalic and wing venation characters; definitive identification requires examination of adult specimens. Larvae of the family are recognized by their free-living, predatory morphology with well-developed legs and absence of portable cases. Specific genera within the family are distinguished by larval head capsule pigmentation patterns, prosternal sclerite characteristics, and femoral process morphology on chelate forelimbs.

Larvae inhabit lotic freshwater environments including streams and rivers. Species occupy a range of hydraulic conditions from moderate flow to torrential waters. Microdistribution patterns correlate with water velocity, depth, and substrate size; larger larvae tend to occupy faster-flowing microhabitats. Adults are collected near stream environments, often using light traps positioned adjacent to water bodies.

Neotropical region (Brazilian Subregion, Central America, Antilles, southwestern USA), with notable absence from the Chilean Subregion. Australasian region including Australia (south-eastern and south-western), New Zealand (South Island alpine regions), and New Caledonia. Pantepui biogeographical region in Venezuela.

Complete metamorphosis with egg, larval, pupal, and adult stages. Eggs are deposited in plaque-shaped masses attached to the underside of rocks protruding above the water surface. Larvae are aquatic and free-living; last instar larvae described for some species. Adults collected at light traps typically operate from evening hours (6 p.m.) to midnight.

Adults exhibit positive phototaxis to ultraviolet and visible light (360-780 nm spectrum). Larval microdistribution is influenced by hydraulic conditions, with larger individuals showing increased occupancy of high-velocity habitats. Oviposition occurs on emergent rocks with egg masses positioned on undersides to avoid desiccation and predation.

Larvae function as predators in stream ecosystems, contributing to benthic food web dynamics. Density distributions correlate with hydraulic parameters including Froude number, boundary layer Reynolds number, and shear velocity, indicating sensitivity to flow regime. Family serves as a potential model system for studies of aquatic insect ecology and oviposition behavior.

Used as indicator taxa for stream ecosystem health and hydraulic condition assessment. Light-trapping methods for adult collection provide accessible monitoring tools. Some species endemic to restricted regions (e.g., New Caledonian Xanthochorema) may have conservation significance.

• RhyacophilidaeAlso within Rhyacophiloidea and shares free-living, predatory larval habit; distinguished by adult genitalic and larval head capsule characters
• PhilopotamidaeOccurs in similar lotic habitats but larvae construct silken retreats for filter-feeding rather than free-living predation

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• The larva of Hydrobiosis torrentis Ward (Trichoptera: Hydrobiosidae)
• Taxonomy of Atopsyche Banks (Trichoptera: Hydrobiosidae) from Brazil: New species, distributional notes and identification key
• The genus Atopsyche (Trichoptera, Hydrobiosidae) in Peru, with the description of seven new species
• A new species of the New Caledonian endemic genus Xanthochorema Kimmins, 1953 (Insecta: Trichoptera: Hydrobiosidae)
• Four new species and new records of Atopsyche Banks (Trichoptera: Hydrobiosidae) from Pantepui biogeographical region (Venezuela)
• Larval descriptions of the Hydrobiosidae, Philopotamidae, Hydropsychidae and some Ecnomidae (Trichoptera) from South-western Australia, with notes on Biology
• Egg masses of some stream‐dwelling caddisflies (Trichoptera: Hydrobiosidae) from Victoria, Australia
• Effects of hydraulic conditions and larval size on the microdistribution of Hydrobiosidae (Trichoptera) in two New Zealand rivers
• Diversity and distribution of the caddisfly genus Atopsyche Banks, 1905 in Ecuador, with the description of seven new species (Trichoptera: Hydrobiosidae).