Genus Nemopterella Banks, 1910

Synonymy

Eretmoptera Navás, 1910: 359 (Preoccupied by Eretmoptera Kellogg, 1900, Diptera)

Nemopterella Banks, 1910: 390; Navás 1911: 226.

Nemeva Navás, 1915: 35; Tjeder 1967: 454 (synonymy).

Type species. Nemopteryx africana Leach, 1815, by original designation.

Diagnosis. Medium to large species that can be distinguished by: (1) tip segment of antennae in the males as well as females terminates in an acute tooth (Fig. 8); (2) vertex of head broad with a pair of yellow or dark transverse spots along the postfrontal suture on the frons above antennae (Fig. 9); (3) forewings with a whitish pterostigma (Fig. 7a); (4) anal area tinged brown or dark brown (Fig. 7b); (5) number of costal cells between 23–37; (6) the entire hind wing from base to the apical whitish area bears black setae (Fig. 10); (7) fifth abdominal tergite with a pair of pleuritocavae on each side (Fig. 3); (8) thorax and abdomen with distinct brown to dark brown longitudinal mid and lateral-stripes; (9) costal crossveins (Cx) and area between the Cx tinged brown to light brown.

Size (mm). Male: body length 7–12.7; forewing 20.5–32.2; hind wing 42.4–73.1; antenna 14.3–37.2; Female: body length 8.7–15.1; forewing 17.5–28.7; hind wing 34.5–62.3; antenna 13.2–20.2.

Redescription. Head. Large with long rostrum (Fig. 9). Vertex broad with dark midline along epicranial suture and a pair of yellow or dark sub-triangular transverse spots along postfrontal suture on frons above antennae. Frons above antennae markedly elevated. Eyes large, widely separated. Antennae in males show intraspecific variation, some not reaching pterostigma others reaching just beyond pterostigma, while some extend beyond the wing (Figs 11–13). Tip segment ends in an acute tooth (Fig. 8). In females, antennae are short not reaching pterostigma and ending in acute tooth on the tip segment. In some species, the head bears distinct very sparse short black hairs over vertex and genae.

Thorax. Pruinose, with distinct longitudinal brown or dark brown mid and two lateral stripes. Pronotum short, narrow, elevated in the middle bending downwards laterally with saddle-like shape and elevated fore margin with upwardly reflexed hind margin. Mesonotum broad, metanotum shorter narrower than pronotum. Pubescence differs between sexes being longer, denser and softer in males than in females.

Forewings. Hyaline. Differing between sexes, slender in males and broader in females. Male forewings with an acute or sub-acute apex combined with a slight or shallow emargination before the apex or in some species with a rounded apex without distinct emargination. In females, forewings have a rounded apex without emargination. Pterostigma is mainly white (Fig. 7 (a)). Area between costa (C) and subcosta (SC), as well as anal area tinged brown. In most species, the subcostal and radial areas tinged brown with adjacent costal cells beyond pterostigma tinged greyish brown. Costal crossveins (or costals) (Cx) vary from 23–37. Hind wings very narrow, ribbon-like, with four distinct portions: the proximal portion near wing base pale or fuscous in colour, the portion before the dark area pale whitish, the dark area brown or dark brown, apical portion white. Setation black from wing bases to apical white portion (Fig. 10). Legs slender, covered with black setae, in some species the coxae covered with white setae; femora and tarsi either with or without tinged tips Tarsal segment 1 longer than segments 2–5 combined.

Abdomen. Cylindrical with short segments and very distinct brown or dark brown mid and lateral stripes (Fig. 3). In males, tergite 5 has short folds at hind margin with a pair of spongy structures, pleuritocavae, that open between tergites 5 and 6 (Fig. 1 (a)). Fore margin of tergite 6 is much larger than fore-margins of other abdominal tergites. These structures are absent from females. Setation of abdomen different in sexes, always longer and denser in males than females.

Genital structures of males and females are similar in the different species with no significant differences observed, so are of little value in distinguishing between species. In males, the gonarcus bears a long mediuncus and the gonolatus and gonosetae are present. Parameres long, fused apically (Figs 4, 5). Females with short gonapophyses laterales.