Mayfly Species Ephemerella needhami (Little Dark Hendricksons)

A rather small, dusky species, having a brownish area at the base of the fore wing; venation faint smoky, brownish at base; no spines on penes.

Head dark reddish brown; frons yellowish; antennae reddish brown; eyes bright orange-red. Thorax deep red-brown, the pronotum largely black; mesonotum brownish black. Sternum somewhat paler, tinged with yellowish. Fore leg smoky brown, the femur slightly paler than tibia and tarsus, and with a small reddish apical spot. Tibia about twice as long as the femur. Middle and hind legs yellowish, the femora usually with a longitudinal ruddy streak and a reddish apical spot. Wings hyaline; a brownish spot at the base of the fore wing; longitudinal veins faintly smoky; Sc and R of the fore wing brownish at extreme base. Stigmatic area opaque whitish; cross veins anastomosed near the costal margin.

Abdomen deep reddish to blackish brown dorsally, usually tinged with wine-red. Posterior margins of tergites blackish brown. Traces of pale brownish submedian streaks on each side of the dark median line may be present. Pleural fold blackish brown. Venter usually, but not always, distinctly tinged with wine-red. Dark markings consist of two short oblique submedian streaks at the anterior margin, and two small dark dots nearer the center of each sternite. Genitalia light reddish brown. Second joint of the forceps not swollen at the apex. Penes separated apically by a wide rather V-shaped notch; no spines are present (see fig. 155). Tails deep smoky brown; joinings not distinct.

The nymphs are rather variable in color pattern, ranging from dark reddish brown to almost black; usually but not always, a broad pale median line is present on thorax and abdomen. Within this pale stripe may be a dark median line; the pale stripe itself is bordered by darker stripes. The prothorax is pale on the lateral margins; on the mesothorax, between the wing buds, are often two small pale rounded spots. Head and thorax smooth. Tergites 2-8 each bear erect dorsal spines, shortest on tergite 2, where the spines are also closest together. On the following tergites the spines are roughly parallel, not diverging as in E. hystrix (Now a synonym of Caudatella hystrix). Each spine bears several minute spinules on its upper surface. Lateral extensions of the abdomen only moderately developed, and with short postero-lateral spines. Venter marked as in the imago, with dark submedian oblique streaks at the anterior margin and two dark dots nearer the center of each sternite. Tails pale yellowish, with one or two dark bands at the base and apex only.