Angustocera plana, Ingrisch, 2023

Ingrisch, Sigfrid, 2023, New and little-known genera and species of Agraeciini (Orthoptera: Tettigoniidae: Conocephalinae) from New Guinea, Zootaxa 5249 (2), pp. 190-212 : 209-212

Angustocera plana sp. nov.

Figs 10–11

Holotype (male): Indonesia: Papua, Paniai District (Wissel Lakes), Wisselmaren, Enarotadi , elev. 1900–2000 m (- 3.91667, 136.35000), 2.vii.–2.xi.1962, coll. J.L. Gressitt (depository: Honolulu, BPBM).

Other specimen studied: Indonesia: Papua, S. Geelvink Bay, Nabire , elev. 3 m (-3.366667, 135.483333), 2– 9.vii.1962, coll. J.L. Gressitt — 1 female (allotype; Honolulu, BPBM) .

Diagnosis. As described under genus.

Description. Small, but long and narrow species. Head elongate, dorsal surface with a shallow impression in posterior half; vertex prolonged, anterior margin in lateral view curved ventrad and then terminating into a long and acute, projecting fastigium verticis with curved, acute tip. Face narrow conical, prolonged, dark brown but in middle with a large pale triangular spot; surface faintly rugose but shining. Pronotum elongate, fore and hind margins concave, rim distinct but very narrow, transverse furrows indistinct, along midline with a faint medial furrow that is replaced by a faint carina in apical area; lateral lobes very narrow (low) with nearly straight ventral margin; auditory swellings only faintly expressed but forming roundly projecting lobes at about beginning of apical third of lobes. Tegmina reduced to small oval flaps, hind wings absent. Prosternum smooth, without spines; mesoand metasternal lobes rounded. Abdomen elongate and narrow. Femur of fore legs compressed but except at end doso-ventrally widened, in basal area with only one ventral margin that afterwards forms the anterior margin which carries one small and two distinct spines while the posterior margin is rounded and smooth; mid femur less strongly dorso-ventrally widened with anterior margin provided with four ventral spines around mid-length: the central two moderately large, while the anterior and posterior spines very small; posterior margin only indicated, nearly absent; hind femur with basal area rather stout and widened, with two ventral margins that are fused in the compressed apical half of the femur to a single ventral margin except just before hind knee lobe, anterior ventral margin with six spines, hind knee lobes with one spine each. Anterior tibia with tympanal area swollen but tympanal openings reduced to small narrow slits on both sides. Hind tibia with angles rounded, on dorsal side with 8 anterior (external) and 9–10 posterior (internal), markedly large, black spines sitting on black spots; on ventral margin with 6 thin anterior spines; on both sides with three apical spurs. Apical area of hind tibiae loosely setose. Femora with the following number of spines on ventral margins: fore femur 2–3 anterior, 0–3 minute posterior; mid femur 3–4 anterior, 0 posterior; hind femur 4–6 anterior, 0 posterior. Hind knee lobes with one spine on both sides.

Male. Wings reduced to stridulatory apparatus, in situ hidden under pronotum. Stridulatory file on underside of left tegmen 0.83 mm long with 57 teeth; area with distinct, countable teeth 0.65 mm with 39 teeth. Tenth abdominal tergite wider than long; apical margin extended into a pair of rounded-triangular lobes. Cerci short and wide; along internal margin somewhat depressed but in about posterior half triangularly projecting with a small spine at tip; end of cercus stem obtuse. Subgenital plate wide and convex with upcurved lateral margins; apical margin truncate with lateral angles extended into triangular, re-curved projections with acute tip; ventral surface of plate strengthened along midline by a stout bulging ridge. After closed by a pair of vaulted sclerotized plates of about rectangular appearance. Phallus largely membranous, with a pair of about vertically inserted, roughly rectangular and balloonlike inflated, but somewhat compressed packs that are stiffened but not sclerotized, with granular surface and bilobate end.

Female. Last abdominal tergite with a medial furrow, and with a little projecting apical lobe on both sides of that furrow; cerci conical. Subgenital plate separated from preceding sternite by a prolonged membranous area which is collapsed to a compressed projection in specimen at hand; subgenital plate proper rhombic and also little roofshaped, at base on both sides with an oval groove with sclerotized surface, afterward with little converging lateral margins, apical margin substraight or slightly convex but on both lateral angles provided with a conical projection; surface of subgenital plate and apical cones but also base of ovipositor provided with scattered, distinct hairs. Ovipositor with basal area swollen, afterwards narrow, curved, with subobtuse tip.

Measurements (1 male, 1 female).—body: male 16.5, female 18; pronotum: male 5, female 4.25; tegmen: male 1.5, female 1; hind femur: male 7.7, female 7.7; ovipositor: female 7.5 mm.

Etymology. The new species is named for the flat shape of the body when seen in lateral view; from Latin planus, plana flat.

Figures

FIGURE 10. Angustocera plana sp. nov. male holotype: A–D, Habitus in lateral (A), ventral (B), dorsal view (C), and in greater detail (D); E, hind tibia; F, pronotum in oblique and tegmina in dorsal view; G, stridulatory file; H, end of abdomen in oblique dorsal view; I, phallus with titillators and subgenital plate from behind.—Scales: 10 mm (A–C), 5 mm (D), 1 mm (F–I).—Abbreviations: 10t tenth abdominal tergite, ac anus cover, ce cercus, sa supra anal plate, ti titillator, vr ventral rim on underside of subgenital plate.

FIGURE 11. Angustocera plana sp. nov. female allotype:A–C, Habitus in lateral (A), dorsal (B), and ventral view (C); D, head, pronotum and tegmen; E, face and fore legs; F–G, subgenital plate in lateral (F) and ventral view (G).—Scales: 10 mm (A–B), 5 mm (C), 1 mm (E–G).