Mayfly Species Procloeon rufostrigatum (Tiny Sulphur Duns)

Abdominal tergites of male imago pale yellowish white, each with a row of four minute red transverse dashes on the posterior margin on each side.

Face and thorax deep blackish brown. Thoracic sternum deep black brown; posterior margin of mesonotum and pleural sutures tinged with pale yellowish brown. Legs pale yellowish white. Wings hyaline. Hind wing long and narrow, two longitudinal veins (see fig. 165). Abdominal segments 2-6 pale yellowish white; each tergite with a lateral row of four minute red transverse dashes on each side, these dashes situated on the posterior margin of the tergite. Tergites 7-10 deep chocolate brown, sternites alabaster white; the pleural fold forms a sharp division between these two colors. A faint slightly curved hair-line of black marks the spiracular area, on the pale segments. Forceps and tails white. Inner margin of second joint of the forceps with a poorly developed inward bulge, much less apparent than in C. caliginosum (now a synonym of Procloeon caliginosum) (see fig. 166).

From the allied C. caliginosum, this species may be separated by the smaller size, and the lesser development of the bulge on the second forceps joint. The much narrower hind wing distinguishes it from C. bifurcatum (now a synonym of Anafroptilum bifurcatum).