Ocellarnaca nigrofemora Shi & Zhu 2021, sp. nov.

2 Ocellarnaca nigrofemora sp. nov.

(Figs 2, 4)

Description. Body medium. Face ovoid, frons smooth. Fastigium verticis broad, width as about two times that of antennal scapus. Eyes ovoid, comparatively small, protruding outwards. Median ocellus large; lateral ocelli small. Pronotum short and broad, anterior margin lightly protruding forward, posterior margin slightly concave. Second and third abdominal tergites each with two rows of stridulatory pegs.

Wings comparatively long, reaching apex of postfemur. Tegmina: Radius with two branches: media anterior has a common stem with radius, arising after end of basal half; media posterior absent; cubitus anterior undivided; cubitus posterior undivided, free throughout; with 4 anal veins plus a short and weak incomplete vein at hind margin of tegmen. Hindwings shorter than tegmina.

Legs. Procoxa with a spine at anterior margin, profemur and mesofemur unarmed on ventral surfaces, protibia and mesotibia with four pairs of long spines and a pair of short apical spurs on ventral surfaces. Postfemur with 7 inner spines and 5 outer spines on ventral surface; posttibia with 5–6 spines on both sides on dorsal surface separately, apex with a pair of dorsal spurs and two pairs of ventral spurs.

Coloration. Head and pronotum yellowish brown, labrum reddish brown, mandible brown. Eyes brown. Median ocellus yellowish white, lateral ocelli light yellow. Profemur and protibia black, spines and spurs on ventral surface light. Mesotibia is similar to protibia, but dorsal surface on mesofemur grey. Postfemur with dorsal surface grey; posttibia black. Veins light, cells brown. Male eighth and ninth abdominal tergites black, projections of ninth abdominal tergite black including the appendages.

Male. Ninth abdominal tergite shorter, subapex of ventral surface with one pair of short conical projections, distance between which wide, apices rounded; ventral surface of every projection with a robust and short process. Cerci long conical, apices rounded. Subgenital plate broad and short, posterior margin concave. Styli medium length, cylindrical, apices rounded, inserted on lateral sides of subapex of subgenital plate.

Female. Unknown.

Specimen examined. Holotype: male, Bingzhongluo, Gongshan, Yunnan, China, 11 August, 2018, collected by Kai Sun and Zhi-Peng Li.

Measurement (mm). Body: ♂ 21.0; pronotum: ♂ 4.9; tegmen: ♂ 15.5; postfemur: ♂ 12.0.

Discussion. The new species is different from known species of the congener in: male ninth abdominal tergite with one pair of short conical projections on subapex of ventral surface, distance between wide, apices rounded; ventral surface of every projection with a robust and short conical process; legs black.

Etymology. The new species is named for black femora; from Latin nigr - (black) and femor -(femora).