Prosopogryllacris silacea, 2018

Ingrisch, Sigfrid, 2018, New taxa and records of Gryllacrididae (Orthoptera, Stenopelmatoidea) from South East Asia and New Guinea with a key to the genera, Zootaxa 4510 (1), pp. 1-278 : 89-90

Prosopogryllacris silacea sp. nov.

Figs. 27 A–I

Material examined. Holotype (male): East Malaysia: Sabah, Mt. Kinabalu, Poring , elev. 500–700 m (6°5'N, 116°33'E), 26.ii.1996, leg. A. Floren (D Apo)—(Bonn ZFMK).

Other specimens: same locality as holotype: 12.ii.1993, leg. A. Floren (tree nr. 9)— 1 female (paratype) (Bonn ZFMK) ; same locality, 19.iii.1993, leg. A. Floren (tree nr. 70)— 1 female (paratype) (Bonn ZFMK) ; same locality, 7.xi.1996, leg. A. Floren— 2 females (paratypes) (Bonn ZFMK) .

Diagnosis. The general habitus of the new species, the large median ocellus, and the arming of the male ninth abdominal tergite are typical for Prosopogryllacris , while the yellowish coloration of the hind wings with distinct dark brown oval maculae along the cross veins resembles that of Xanthogryllacris . With regard to the shape of the male ninth abdominal tergite with a pair of globular swellings above hind margin, P. silacea sp. nov. resembles X. p. aurantiaca Brunner. It differs however by the shape of the projections below those swellings that are styliform, slightly sinuate and with acute tip while in X. p. aurantiaca they form short, dorso-ventrally compressed subacute teeth. The transverse subgenital plate with slightly bilobate apical margin is also similar between both species. Females can be recognized by the seventh abdominal sternite that is distinctly wider than long and is provided with a broad but short projection from hind margin just reaching the tip of the ovipositor. The moderately curved, elongate ovipositor is characteristic for a shallow but distinct excision of the dorsal margin just before subapical widening ( Fig. 27H ). From X. punctata sp. nov. and X. lineata sp. nov., both also found in Sabah, P. silacea differs by the black face with the fastigium frontis not markedly outlined as in both other species, by the oval spots along the cross-veins of the hind wings, and by the distinct swellings above hind margin of male ninth abdominal tergite with styliform projections instead of compressed teeth.

Description. Medium sized species. Head: Face robust but not particularly large; in frontal view ovoid; forehead nearly smooth, with scattered but rather large impressed dots; fastigium verticis little wider than scapus; median ocellus distinct and large, lateral ocelli small; fastigium frontis separated from fastigium verticis by a fine transverse suture ( Figs. 27C ). Abdominal tergites two and three each with two rows of very weak stridulatory pegs (0–1, 4–5; 4–8, 7–12; n = 1 male, 3 females; Fig. 27I ).

Wings reaching or little surpassing tip of hind femur ( Fig. 27 A–B). Tegmen: Radius with two branches, dividing before mid-length of tegmen, both forked near tip; media anterior fused in about basal quarter with radius, afterwards single-branched; media posterior absent; cubitus anterior forks into two veins between end of basal quarter and half-length of tegmen; cubitus posterior undivided, free throughout; with 3 anal veins.

Legs: Fore coxa with small spine at fore margin; fore and mid femora unarmed; fore and mid tibiae with 4 pairs of long ventral spines and 1 pair of smaller ventral spurs; hind femur with 6–9 external and 5–12 internal spines on ventral margins, little increasing in size towards posterior end (on external side only in apical half); hind tibia with spaced spines on both dorsal margins, both ventral margins with a pre-apical spine; with 3 apical spurs on both sides.

Coloration. General color yellowish brown (body, wings) to reddish (pronotum, legs). Face black; fastigium, median ocellus, basal segments of antennae and labrum pink or dark reddish brown; clypeus along lateral and ventral margins whitish. Tegmen yellowish transparent, veins yellow; hind wing yellowish transparent, only at very base brown, cross veins blackish brown and encircled by oval blackish brown spots.

Male. Eighth abdominal tergite prolonged, at least twice as long as preceding tergites. Ninth abdominal tergite curved down and faintly furrowed in midline except in basal area, in apical area forming a pair of strongly swollen semi-globes with rounded apical margin. Below the semi-globes with a pair of narrow projections, that are in basal areas pale, moveable and largely hidden under the semi-globes; in midline between semi-globes curved dorsad and darkened, slightly sinuate and with subacute tip ( Figs. 27 E–F). Subgenital plate rather short; apical margin wide bilobate; with a pair of moderately long, conical styli ( Fig. 27D ). Phallus membranous.

Female. Seventh abdominal sternite transverse, strongly setose, hind margin in middle with a roughly semicircular projection to base of subgenital plate. Subgenital plate at base membranous and striated, otherwise about triangular with tip divided into two angular, obtuse lobes ( Figs. 27G ). Ovipositor elongate, regularly curved dorsad, with lateral furrow ending before apical area; subapical area narrowed followed by apical widening of dorsal margin; tip obliquely acute ( Fig. 27H ).

Measurements (1 male, 4 females).—body w/wings: male 27, female 24–25; body w/o wings: male 21, female 18–22; pronotum: male 4.5, female 4.5; tegmen: male 19, female 17–19; tegmen width: male 6.8, female 6; hind femur: male 12, female 12–14; antenna: male 90, female 80–120; ovipositor: female 14 mm.

Etymology. The new species is named for the ochre coloration of the hind wings with oval dark spots around the cross veins; from Latin silaceus (ochre).

Figures

FIGURE 27. Genus Prosopogryllacris: A–I, P. silacea sp. nov.; J–M, P. nigra sp. nov.—Habitus dorsal view (A–B, J), face (C, K), male abdominal apex in ventral (D), apical (E), and oblique lateral view (F), female abdominal apex with base of ovipositor in ventral view (G, L), ovipositor (H, M), stridulatory pegs on second and third abdominal tergites, front is left (I).— Male holotype (A, C–G); female paratypes (B, H–K). Scales 10 mm (habitus, ovipositor), 1 mm (face).