Family: Ephemeridae, Burrowing Mayflies view all from this family

Description These Mayflies are members of the burrowing mayfly family (family Ephemeridae). Many of the largest and most common North American mayflies belong to this family. Some measure more than 1" (25 mm) excluding the 2 or 3 tail filaments, which may be even longer. Adults are distinguished from mayflies in most other families by their 4-segmented tarsi. The spindle-shaped naiads have sharp, tusklike mandibles, fringed gills on abdominal segments 2-7, and fore legs adapted for digging in the muddy bottoms of rivers, lakes, or gently flowing streams. Most North American species are found in the East, usually in water no more than a few yards deep.