Ocellarnaca fusca Ingrisch 2018, sp. nov.

Ocellarnaca fusca sp. nov.

Figs. 21 C–D, 22C–F, 24C–D

Material examined. Holotype (female): Vietnam: Hanoi prov., BaVi N.P., (21°4'4''N, 105°21'30''E), 25– 29.vi.2015, coll. J. Constant & J. Bresseel (I.G.: 33.092)—(Brussels RBINS).

Other specimens: same data as holotype— 1 female (Brussels RBINS).

Diagnosis. The new species is similar to O. disjuncta sp. nov. in general appearance and with regard to the female abdominal apex. It differs by the apico-lateral projections of the seventh sternite that are shorter and more roundly projecting than in O. disjuncta and especially by the subgenital plate that is provided with a distinct basal groove, by the apical lobes that are in top view rounded at tip not truncate, and in lateral view the subgenital plate is in basal area bulgy then strongly narrowed and slightly curved while in O. disjuncta it is in lateral view about equally elevated, strongly curved before apical margin that terminates in a lateral angle. The coloration of the wings of O. fusca sp. nov. is similar to that of O. wolffi (Krausze, 1906). But O. fusca has a short and upcurved instead of a long ovipositor and less strongly reduced wings with larger surface of the hind wings. Moreover, the shape of the seventh abdominal sternite of female and the shape of the subgenital plate are quite unique in new species.

Description. Rather short and stout species. Head: Face ovoid; forehead with transverse furrows and fine riffles and scattered impressed dots; fastigium verticis distinctly wider than scapus, separated by a transverse suture from fastigium frontis; ocelli very distinct, whitish; median ocellus very large; with week, indistinct subocular furrows (Figs. 22 C–D). Abdominal tergites two and three with very small stridulatory pegs.

Wings about reaching hind knee (Figs. 21 C–D). Tegmen: Radius with two branches; RS arises in apical third and forks once more near tip; media anterior has a common stem with radius, arising as first posterior branch of R in about mid-length of tegmen; media posterior absent; cubitus anterior undivided; cubitus posterior undivided, free throughout; with 6 anal veins, the last vein shortened.

Legs: Fore coxa with a spine at fore margin; fore and mid femora unarmed; fore and mid tibiae with four pairs of large ventral spines and one pair of smaller ventral spurs; hind femur with 5–9 external and 10–12 internal spines on ventral margins, the basal spines very small; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine; with 3 apical spurs on both sides.

Coloration (holotype): General color light medium brown with femora except for baso-dorsal area and tibiae of all legs black. Face dark maroon brown except for light ocelli, towards genae and mandibles darker; ventral area of clypeus yellowish. Tegmen with veins, veinlets and immediately bordering areas white; cells dark brown, towards anterior and apical margins paler; hind wing dark brown, lighter towards tip; main veins blackish brown, lighter towards anterior margin and tip; cross-veins bordered on both sides by white bands. Ovipositor in basal area black, except for light ventral surface, afterwards yellowish brown.

Coloration (second female): General color light to medium brown without distinct pattern except for wings; legs medium to dark brown. Face uniformly reddish brown except for light ocelli; ventral and lateral margins of clypeus yellowish, mandibles dark brown. Tegmen semi-transparent whitish, towards middle and base yellowish, with greyish or yellow veins and veinlets, cells with pale brown, towards base dark brown spots in middle; hind wing semi-transparent greyish with yellowish brown main veins and grey cross-veins, cells with grey spots in middle.

Male unknown.

Female. Seventh abdominal sternite longer than preceding sternite; with medial furrow; widening apically with greatly rounded apico-lateral angles and wide, faintly concave apical margin; surface black or blackish brown except for pale apical and apico-lateral margins (Fig. 24D). Subgenital plate wide-bilobate with a large and deep transverse basal groove; surface black, only bottom of groove yellowish; in lateral view bulbous in more than basal half, narrow and curved in apical area (Fig. 22F, 24C). Ovipositor in subbasal area strongly upcurved, afterwards only faintly curved, lateral surface with longitudinal furrow; margins approaching till about middle of upcurved area then diverging again; tip subobtuse (Fig. 22F).

Measurements (2 females).—body w/wings: 25–27; body w/o wings: 22; pronotum: 5.5–6.5; tegmen: 17–19; tegmen width: 6.5–8.9; hind femur: 13–15; antenna: 80–120; ovipositor: 9 mm.

Discussion. Apart from the holotype there was a second female collected at the same place and time that had not been fully hardened after final molt. In that female the subgenital plate is distorted with the lateral parts are flat and flipped mediad. It is also of much lighter color than the holotype.

Etymology. The new species is named for the dark brown coloration; from Latin fuscus (brown, dark).