Apterolarnaca (Bianigryllacris) trigonistis sp. nov.

ssṱoûãșŝ

Figure 1

Description. Female. Body medium. Face ovoid, with impressed scattered dots; fastigium verticis about 2 times as wide as scape; fastigium frontis separated from fastigium verticis by a very fine suture (Fig. 1A). Ocelli indistinct (Fig. 1A).

Anterior margin of pronotum projected in middle, posterior margin faintly concave (Fig. 1B); lateral lobes longer than high, anterior angle widely rounded, posterior angle arched (Fig. 1C).

Fore coxae with 1 spine on each side. Fore tibiae with 4 pairs of ventral spurs and 1 pair of ventro-apical spurs; middle tibiae with 1 dorso-apical spine, 3 pairs of ventral spurs and 1 pair of ventro-apical spurs. Hind femora with 7 8 internal and 3 6 external spines on ventral surface; tibiae with 4 pairs of fine spines on dorsal surface, apices with 1 pair of dorsal spurs and 2 pairs of ventral spurs.

Second and third abdominal tergites with few, very minute stridulatory pegs (Fig. 1D). Seventh abdominal sternite longer than proceeding sterna. Subgenital plate with straight basal margin, lateral margins faintly curved ventrad and narrowing to apex, apex acute (Fig. 1G). Ovipositor short and strongly curved upwards, with dorsal and ventral margins smooth, its apices narrowly rounded (Fig. 1F); with a pair of triangular, lateral lobes at base of ventral valvulae (Fig. 1G).

Male. Unknown.

Coloration. Body yellow-brown. Face with 1 longitudinal black stripe. Front-clypeal sulcus black with 1 pair of black spots (Fig. 1A). Fastigium verticis with narrow transverse black stripe. Internal margins of antennal cavities black (Fig. 1A). Antennae with black rings on each segment. Dorsal surface of head with semicircular black stripe. Dorsal surface of body with narrow longitudinal black band. Pronotum with black margins. Lateral margins of mesonotum and metanotum black.

Measurements (mm). Female: BL 22.53, PL 5.04, HFL10.03, OvL 8.11.

Material examined. Holotype: female, Kengdi, Shouning, Fujian, July 17, 2023, coll. by Fanduo Cai.

Discussion. The new species differs from Apterolarnaca (Bianigryllacris) sicula Zhang & Bian, 2023 by dorsal surface of body with narrow black band along the midline; female subgenital plate with lateral margins curved ventrad and terminating, posterior margin acute; basal area of ovipositor with a triangular lobe on each side (Fig. 1G).

Etymology. The new species is named for the basal area of ovipositor bearing 1 pair of triangular lateral lobes; from Latin trigon.