Periphyton
Guides
Epeorus longimanus
flatheaded mayfly
Epeorus longimanus is a flatheaded mayfly species in the family Heptageniidae. Nymphs inhabit stream riffles and show specific microhabitat preferences, being more abundant in areas with smaller sediment sizes, higher live periphyton biomass, and lower densities of invertebrate predators. The species is distributed across western North America from Alaska through the western United States to southwestern and northern Canada.
Helicopsyche borealis
Spectacled Snail-case Caddisfly
Helicopsyche borealis is a caddisfly species in the family Helicopsychidae, notable as one of only two Helicopsyche species to colonize temperate North America from a predominantly tropical genus. Larvae construct distinctive spiral, snail-like cases from sand grains cemented with silk. The species inhabits running waters across North America and plays a role as a collector-gatherer and scraper in stream ecosystems. Adults emerge in spring, and the life cycle is univoltine with egg diapause through summer.
Molanna uniophila
Molanna uniophila is a caddisfly species in the family Molannidae. Larvae inhabit shallow, sand-bottomed lake margins and construct portable cases from sand grains and organic debris. They exhibit distinctive diel foraging behavior, migrating from sandy substrates to hard surfaces (rocks, wood, macrophytes) during evening and night to feed on periphyton, then returning to sandy areas by day. Adults display sex-dependent antennal dimorphism associated with asymmetric pheromone communication, where only females produce volatiles.