Genus Nacolus Jacobi

Nacolus Jacobi 1914: 381; Schumacher 1915: 97; Evans 1946: 46; Esaki and Ito 1954: 26; Kuoh 1966: 111; Zhang 1990: 40. Type species: Nacolus gavialis Jacobi, a junior synonym of Prolepta (?) tuberculatus Walker 1858 (here synonymized).

Ahenobarbus Distant 1918: 28; Evans 1946: 48. Synonym of Nacolus Jacobi 1914 . Type species: Ahenobarbus assamensis Distant.

Mellia Schmidt, 1920b: 127 . Type species: Mellia granulata Schmidt.

Melliola Hedicke 1923: 72 . nom. nov. pro Mellia Schmidt 1920b . syn. n.

Diagnosis. This genus can be easily distinguished from other genera of Hylicinae by the oar-shaped head with length at least 3.0x longer than width.

Description. Medium to large leafhoppers (body length 11.3–19.8 mm), female usually larger than male. Yellow brown to dark and densely covered with tiny setae, male usually darker than female. Crown (Figs. 1, 3, 12, 14, 22–23, 27–31, 37–43) produced forward in front of eyes, about 3–6.0x longer than width, female usually slightly longer than male, median longitudinal carina through crown with terminal half slightly sinuate and with several small tubercles, lateral carina extended outward and downward and then narrowing forward and curved upward, joined with median longitudinal carina at apex, one pair of submedial ovoid depressions without setae between eyes near posterior margin, eyes reniform, ocelli located slightly anterad of eyes on small tubercles near lateral margin. Face (Figs. 2, 13, 32–36) long and narrow, frontoclypeus slightly concave in profile, obviously longer than anteclypeus, anteclypeus apex extended slightly beyond lower margin of gena, lorum narrow and short, well separated from gena, gena exposing long and narrow proepisternum, rostrum extended beyond front coxae but not reaching middle coxae. Pronotum (Figs. 1, 3, 12, 14, 22–23, 27–31, 37–43) trapezoidal with lateral margin carinate and slightly concave in middle, surface granulose and transversely rugulose, median length slightly shorter than width of posterior margin, anterior margin slightly produced, posterior margin extended backward with middle concave, elevated posterad and sloping laterally. Exposed part of mesonotum and scutellum (Fig. 5) with surface granulose, and as long as or slightly longer than pronotum. Forewing (Fig. 4) granulose and with somewhat prominent veins, yellow brown and usually brownish on center of upper half tinged or with pair of brunet longitudinal bands, many brunet hair clusters dispersed over surface or not, claval suture obviously folded downward. Abdomen (Figs. 15, 16) yellow brown to dark, with one round protuberance on sternite III center, lateral margins extended only slightly laterad of forewings at rest, nearly parallel-sided and slightly broadened posteriorly, tergites V, VI yellowish, tergite VIII (Fig. 6) with pair of rearward extending protuberances. Front and middle legs generally yellowish brown with some blackish spots, front tibia dilated and compressed, hind legs black with tibia strongly spinulose, all tarsi yellowish.

Male genitalia. (Figs. 7–11, 17–21, 24–26) Pygofer (Figs. 7, 17, 24 (A–E)) base short, separated from lobe by vertical membranous cleft, lobe with many scales, separated into two parts in dorsal view, parallelogram-shaped in lateral view, with many stout short setae on ventral margin. Anal tube (Fig. 8) with pair of long apodemes. Subgenital plate (Figs. 9, 19, 24 (A1-3–F)) with lateral margin evenly convex, gradually narrowing posteriorly and terminating in blunt angle, with scattered scales on ventral surface, valve reduced and fused with base of subgenital plate. Connective (Figs. 25, 26) quadrangular with length about 3.0–4.0x width, lateral margins vertically expanded into keeled process. Style (Figs. 25, 26) with apodeme long, apophysis reduced, lobelike, with many slender setae on ventral apex. Aedeagus (Figs. 25, 26) symmetrical and curved dorsad, preatrium well devleoped, shaft tubular.

Female. Sternite VII (Fig. 44) strongly protruded in an arc backward and overlapping base of ovipositor, tergite VIII (Fig. 46) with two pairs of posterior protuberances, sternite VIII reduced to membrane. Pygofer (Figs. 45, 46) slightly emarginate dorsoapically rather than deeply bifid. Ovipositor (Fig. 45) not reaching pygofer apex. First valvulae (Fig. 47) symmetrical and with base bifurcate, dorsal sculpture area densely strigate. Second valvulae (Figs. 48, 49) blade-like. Second valvifer (Fig. 50) with about twenty sensory setae near point of articulation. Third valvulae (Fig. 51) sheath-shaped with few small setae near ventral margin.

Distribution. China, India (Assam), Japan.