Ept
Guides
Isonychia intermedia
Isonychia intermedia is a species of mayfly in the family Isonychiidae. Like other members of its genus, it is an aquatic insect with a life cycle consisting of an extended nymphal stage in freshwater habitats followed by a brief adult stage. The species is found in North America and is part of the EPT (Ephemeroptera-Plecoptera-Trichoptera) assemblage used in water quality biomonitoring. Adults are known to anglers as 'slate drakes' due to their dark wing coloration.