Mayfly Species Ameletus validus (Brown Duns)

A pinkish brown species, with faint clouds on the fore wing and without dark ganglionic marks on the venter of the abdomen.

Head brownish. Thorax deep blackish brown, the mesothorax light brown on the anterior sutures and around the scutellum. Fore leg deep blackish brown; middle legs pinkish brown. Wings hyaline, veins dark; faintly clouded with light umber brown; palest along outer margin.

Abdomen pinkish brown. Segments 1-6 semi-transparent, the sutures narrowly opaque; segments 7-10 opaque, segment 9 shaded laterally with smoky brown. Forceps base brown, with paler lateral margins and a yellow median area; posterior margin strongly excavated between the forceps; the tubercles on the apical margin well developed. Penes long and slender, curving outward near the tips.

Wing of female lacks the brown clouds. Subanal plate of female larger than in the allied species, Ameletus similior, and reaching nearly to the posterior margin of the tenth segment.