Concavocorona gen. n.

(Figs 1 –21)

Type species: C. supercilia sp. n.

Description. Medium-sized leafhoppers measuring 7.5–8.8 mm in length (including tegmen), dorsal coloration dark brown or black. Head, thorax and forewing with sparse, short, whitish setae. Head (Figs 1, 3, 11, 13) triangularly produced in dorsal view; crown shorter than half distance between eyes, and shorter than pronotum; median longitudinal carina simple, lateral carina and marginal carina distinct and combined in the front of corresponding ocellus, transverse carina indistinct in forepart of crown; lateral carina higher than median longitudinal carina horizontally; area between two lateral carinae concave, with abundant rugae, with round elevated structure at both sides of median longitudinal carina. Ocelli (Figs 3, 13) located at side of lateral carina, closer to corresponding eye than to apex of crown. Face (Figs 4, 14), including eyes, longer than wide, mostly blackish puce; frontoclypeus with median longitudinal carina and oblique lateral striations distinct, with transverse beige patch on anterior margin; lorum shagreen, small, narrow, reaching slightly beyond midlength of clypellus. Pronotum (Figs 3, 13) broad, wider than head, black, with fine transverse striations. Scuto-scutellar suture distinct. Forewing (Fig. 5) with veins slightly prominent, dark brown, R1a present. Front femur with setae AM1 and AV1 enlarged; intercalary row with 6–7 setae; row AV with 11 setae; row AM with short to long dense setae from base to apex, irregularly arranged; rows AD and PD with 12 and 22 shorter setae, respectively; row PV undeveloped. Front tibia with about 50 and 55 setae in rows AD and AV respectively, irregularly arranged; row PV with numerous shorter setae, irregularly arranged; row PD with 25 setae with more distal setae progressively larger. Hind femur macrosetal formula 2+1+1; tibia with ca. 17, 11, 15, and 48 setae in rows PD, AD, AV, and PV, respectively; tarsus elongate, tarsomere I longer than II and III combined, with pair of dorsoapical setae, one posteroapical and 3 longitudinal rows of plantar setae; pecten of tarsomeres I and II with 4 and 5 tapered setae, respectively.

Male pygofer (Figs 8, 9, 15, 17) with long, slender ventral process arising near base, slender proceeding along lower of pygofer and slightly exceeding caudodorsal margin. Subgenital plate (Figs 10, 20) weakly segmented at base, elongate, row of elongate fine setae along interior submargin and numerous long, fine setae sparsely distributed over surface laterad of macrosetae. Style (Figs 7, 16) with footlike apex of apophysis having elongated lateral angle, apodeme apex acute. Connective (Figs 7, 16) Y-shaped, stem much longer than arms. Aedeagus (Figs 6, 7, 18, 19) with bilobed, lamellate apodeme arising from atrium and extended dorsolaterad; with lamellate ventral apophysis; shaft short, recurved dorsally; gonopore apical on dorsal surface.

Etymology. The genus name, a combination of concavo, meaning concaved, and corona, meaning crown, refers to the concave disc of crown.

Distrubution. China, Thailand

Remarks. This genus differs from all other known genera of Evacanthini in having the disc of the crown concave, rugose and with sharp anterior margins, the median longitudinal carina simple, and the lateral and marginal carinae distinct.

Concavocorona gen. n. is similar to Evacanthus Le Peletier & Serville but may be distinguished as follows: 1) The new genus has the disc of the crown concave and rugose; in Evacanthus the disc of the crown is also concave but with a depressed area on either side of the median carina and the surface is smooth. 2) The anterior margin of the crown is rounded in Evacanthus whereas it is triangular in the new genus. 3) A transverse preapical carina on the crown, as an important character of Evacanthus, but this carina is absent in Concavocorona gen. n. 4) Frontoclypeus with depressed compartment on either side of median carina in Evacanthus, but frontoclypeus less strongly convex in Concavocorona gen. n. 5) Ventral process of male pygofer is thick in Evacanthus, but slender in this new genus. 6) In Concavocorona gen. n., the apical macrosetae of hind femur are enlarged and well differentiated, and without any other preapical setae in the apex of hind femur (fig. 21). But the apical macrosetae are small and there are many other preapical setae in Evacanthus .