Mayfly Species Procloeon fragile (Tiny Sulphur Duns)

Abdominal tergites 2-6 of male imago whitish hyaline, slightly brown-tinged, the posterior margins faintly brown.

Turbinate eyes large, narrowly oval, rather kidney-shaped; pale yellow-brown in living insect, bright red in dried specimen. Face yellowish; antennae pale smoky, the bases white. In dried specimen, the face appears dark grey. Thorax shiny blackish brown; pale markings on the scutellum and adjoining areas; pleura brown, with pale markings near the wing bases. Legs white. Wings hyaline. Abdominal segments 2-6 hyaline whitish, slightly tinged with brown, the posterior margins faintly brown; slightly streaked with black, especially in the spiracular area. Tergites 7-10 rather bright brown; sternites opaque white. Second joint of forceps without a conspicuous inward bulge (see fig. 166).

This species may be distinguished from the allied C. ozburni (now a synonym of Procloeon ozburni) by the bright red eyes in dried specimens (blackish brown, in ozburni), and the absence of dark posterior markings on the middle sternites.