Mayfly Species Anafroptilum asperatum (Tiny Sulphur Duns)

Abdominal tergites of male imago semi-hyaline, yellowish with a tinge of brown; one large and two very small protuberances on inner margin of second forceps joint; distal joint very long.

Head and thorax olivaceous brown. Antennae and turbinate eyes yellowish brown. Antero-lateral and postero-lateral margins of mesonotum, a streak anterior to the wing root, and pleural markings, blackish brown; scutellum and a spot on each side of it, yellowish. Median area of metanotum yellowish. Posterior portion of sternum dark brown; a blackish line between this and mesosternum. Legs yellowish white. Wings hyaline, venation pale; 6 to 7 cross veins in stigmatic area, which is not clouded. 2 of these veins are forked near the subcosta, 2 are anastomosed. Hind wing rather wide for its length, much as in C. elsa (now a synonym of Anafroptilum asperatum); 2 longitudinal veins; costal projection rather short but strong (see fig. 165).

Abdominal segments 2-6 semi-hyaline, yellowish; tergites tinged with pale brown, especially along the spiracular area; a faint dark dash over each spiracle, and traces of a narrow broken dark spiracular line. Segments 7-10 opaque, olivaceous brown dorsally, yellowish white ventrally. Tails missing. Forceps somewhat as in C. conturbatum (now a synonym of Anafroptilum conturbatum), but with a single larger median protuberance, beset with minute hairs, on the inner margin of the second joint; near the apex is a minute second protuberance, and a third one near the base (see fig. 166). Third (long) joint distinctly widened toward the apex; a slight protuberance near the base on the inner margin; not bowed. Distal joint relatively longer than in C. conturbatum, being more than half the length of the third joint. Plate between the forceps bases somewhat dome-shaped.

Described as C. elsa

Body length 5 mm, wing length 5-5.5 mm

Abdominal tergites of male imago yellowish with faint brown shading, semi-hyaline; a regularly rounded inward bulge on inner margin of second forceps joint; distal joint long.

Head red-brown; antennae pale, basal joints faintly tinged with red-brown. Turbinate eyes flesh-colored. Thorax red-brown; pleura and anterior portion of mesonotum shaded with yellowish; all sutures, pronotum, posterior portion of mesonotum, small sclerites in pleura below wing, posterior margin of metanotum and most of sternum, darker. Legs pale yellowish white. Wings hyaline, venation pale whitish; pale cloud in stigmatic area. 4 to 5 complete cross veins in this area; between these, several very incomplete ones, sometimes almost horizontal in position. Hind wing quite large, rather wide for its length; costal projection rather small; two longitudinal veins only (see fig. 165).

Abdominal segments 2-6 semi-hyaline; tergites yellowish tinged with brown, especially along the lateral margins; posterior margins scarcely darker than other parts; sternites yellowish white, the basal ones very faintly brown-tinged. Segments 7-10 opaque; tergites pale yellowish brown, the posterior margins very narrowly darker brown; sternites paler, a distinct brownish-red line along the pleural fold on sternite 9. Tails whitish. Plate between the bases of the forceps limbs distinctly convex on its posterior margin. Second joint of forceps with a regularly rounded inward bulge on the inner margin; outer margin distinctly curved, slanting inward at the apex; third (long) joint strongly bowed, widest near apex; distal joint long (see fig. 166).

Head and thorax of nymph light red-brown. Abdomen yellowish; no distinct markings except the reddish brown posterior margins of the segments, most distinct dorsally. Legs yellowish; tarsi and claws tinged with reddish brown. Gills quite large and long; obovate; tracheae not distinct; apparently single on all segments. Tails yellowish, less stout than in the known eastern species, and with no thickened annuli. Middle tail slightly shorter than the laterals. Claws with a few indistinct denticulations; no short spines on lateral margins of segments 8-10, and no postero-lateral spines on any of the abdominal segments.