Mayfly Species Drunella longicornis

A species of the fuscata (now a synonym of Drunella walkeri) group; a very close ally of E. cornuta (now a synonym of Drunella cornuta). Hind femur rather longer relatively than in cornuta; tarsi and tails darker; pleural fold rather widely pale.

Head largely brown. Thorax dark olive brown dorsally. A round pale spot on each side of the median line of the pronotum, which is also pale laterally. A greyish streak anterior to the wing roots; pleura with paler markings. Fore femur yellowish brown, shaded with dark brown; tibia and tarsus dark brown, last tarsal joint paler brown. Femora and tibiae of middle and hind legs yellow margined with brown; tarsi dark brown, paler on the distal joints. Hind femur as long as tibia and tarsus combined. Wings hyaline, longitudinal veins pale yellowish brown; a brown spot at base of fore wing. Abdomen dark reddish brown dorsally; a pale submedian spot on each side of the mid-dorsal line, on the anterior margins of the middle tergites. Pleural fold rather widely pale. Tergites darker brown next to the pleural fold and on the posterior margins. Light yellowish brown ventrally; on each sternite a dark brown lateral streak lies next to the pleural fold. Postero-lateral spine on segment 9 longer than that of cornuta. Tails purplish brown. Third joint of forceps relatively shorter, and second joint less strongly bowed, than in E. cornuta; penes spread more widely at apex (see fig. 153).

Nymph distinguished from cornuta by the longer frontal horns and the longer and more curving tibial spine.

Nymph quite similar to that of E. cornuta. Light reddish in color, the thorax often checkered and mottled with contrasting light and dark areas. Abdomen rather lighter in color than thorax. Frontal horns very long and relatively straight; their length is more than half the width of the space between them (see fig. 151 b). Prominent spines on the anterior margin of the fore femur; its posterior margin almost straight. The ‘thumb’ of the fore tibia is longer than in cornuta, extending beyond the middle of the tarsus; it likewise curves outward sharply in its distal portion (see fig. 154). Postero-lateral spines of the abdominal segments are somewhat longer than in cornuta. Abdomen yellow ventrally, with a row of dark marks on each side, near the pleural fold. Sternites 2-8 hairy, also the posterior margins of the legs. Legs yellowish with indistinct reddish bands.