Bioacoustics of Marthogryllacris erythrocephala

Figs. 3–5 Description. Body large. Fastigium verticis about one and a half times as wide as scape. Face almost smooth, with indistinct dots ( Fig. 3A ). Eyes ovoid. Ocelli distinct, the diameter of median ocellus slightly longer than the lateral ocelli. Anterior margin of pronotum slightly projected in middle, posterior margin nearly straight; lateral lobes longer than deep, with V-shaped furrow, anterior angle widely rounded, posterior angle rounded ( Fig. 3B ). Fore coxae with 1 small spine; fore and middle femora longer than pronotum, unarmed on ventral surfaces; fore and middle tibiae with 5 pairs of spurs on ventral surfaces, the spurs decreasing in size to minute apical ones. Hind femora with 15–17 internal spines and 8–9 external spines on ventral surface; hind tibiae with 5–7 internal spines and 6 external spines on dorsal surface; ventral surface with 1 pair of subapical spurs, apical area with 1 pair of dorsal spines and 2 pairs of ventral spines. Tegmina surpassing the ninth abdominal tergite and slightly reaching the apical third of hind tibiae ( Fig. 5A ). Tegmina ( Fig. 5C–D ): radius with RS branching little after basal third of tegmen, both forked; media anterior free from base; cubitus anterior at base single branched, after divides before basal quarter into two branches, the anterior branch makes a curvature and receives a short connection branch from MA, then divides into MP and CuA1; cubitus posterior undivided, free throughout; with 4 anal veins, the last two with common stem. Second and third abdominal tergites with fine stridulatory pegs ( Fig. 3D ). Eighth abdominal tergite projecting backwards ( Fig. 3F ). Ninth abdominal tergite split along the midline, forming 2 lateral lobes, its basal area roundedly swollen, apical area spine-shaped, crossed each other and directing ventrad and slightly forwards ( Fig. 3E ). Subgenital plate transversal broad, the lateral margins slightly narrowing to apices, basal margin almost straight, posterior margin arched concave; styli stout, cylindrical, longer than the length of subgenital plate, inserted on both sides of subgenital plate near apex ( Fig. 3E ). Female. Body larger than male ( Fig. 5B ). Ovipositor slightly longer than male, dorsal and ventral margins smooth and narrowing to apices, apices obtuse ( Fig. 5B ). Subgenital plate in middle area of anterior margin with 1 pair of copulatory depressions with lateral margins obviously sclerotized ( Fig. 4G ). Coloration. Body yellowish brown. Genae, mandibles and basal area of labrum black. Ocelli yellowish. Pronotum reddish brown with black V shaped stripe, the median area of the stripe with 1 yellowish longitudinal line and 1 pair of reddish spots. Spines of fore and middle tibiae brownish, dorsal spines of hind tibiae black. Measurements (mm). Male: BL 37.0, PL 11.0, TL 48.0, HFL 25.0; Female: BL 40.0, PL 11.0, TL 41.0, HFL 25.0, OvL 26.0.

Discussion. The species is already sufficiently described and its systematic position discussed by Gorochov (2003) and Gorochov et al . (2015). It is recognized by the distinctive color pattern. Head with black genae, labrum and mandibles contrasting with brown vertex, and face and pronotum being black with light anterior spot and posterior margin, in combination with the apical spines of the ninth abdominal tergite male being rather long and narrow, faintly curved with acute tip. The female subgenital plate has at base a transverse groove, which at larger magnification appear to consist of two oval pits. These pits obviously serve as a fix point for the male apical spines of ninth abdominal tergite during copulation, as already supposed by Gorochov (2003) . Additional Description. Medium large species. Head: Face ovoid; forehead in middle with fine riffles, laterally nearly smooth; fastigium verticis wider than scapus; ocelli little distinct; fastigium frontis separated from fastigium verticis by a very fine suture; subocular furrows shallow ( Fig. 48H ). Abdominal tergites two and three with few largely reduced, indistinct stridulatory pegs. Wings surpassing hind knees ( Figs. 46F , 47G ). Tegmen: Radius with two branches, both forked near tip; media anterior arises free from base; cubitus anterior at base with a single branch that forks into two veins, the anterior branch makes a curvature and receives an oblique connection vein from MA and shortly after divides again into two parallel branches, MP and CuA1, while the posterior branch (CuA2) does not divide further; cubitus posterior undivided, free throughout; with 4 anal veins. 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 9–11 external and 8–20 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine; with 3 apical spurs on both sides. Coloration. General color brown; pronotum with a broad transverse black band that can be entire or interrupted; legs light medium brown, tarsi darker. Face red brown, ocelli light yellow; genae, labrum, maxillary palpi and mandibles black; clypeus with 2 irregular black bands. Tegmen semi-transparent yellowish, towards base darker; veins yellow; hind wing semi-transparent ochre, main veins yellow or brown, cross veins dark brown or black adorned on both sides by narrow light or dark brown bands. Male. Eighth abdominal tergite prolonged. Ninth abdominal tergite globular, furrowed in midline, then split and provided at both sides with a large, compressed, curved, acute process, in situ overlapping each other ( Fig. 49D ). Subgenital plate wider than long with diverging lateral margins, surface in middle with a large triangular depression reaching from base to tip, apical margin faintly concave in middle; stout styli almost twice as long as subgenital plate, inserted at apico-lateral angles. Phallus membranous. Female. Seventh abdominal sternite little larger than preceding sternites. Subgenital plate triangular in general outline with all three angles obtuse; in middle of base with 2 small, black, strongly sclerotised, small grooves ( Fig. 51P ). Ovipositor elongate, very slightly curved in basal third, afterwards straight with slightly converging margins; in apical area margins more strongly narrowing but tip obtuse ( Fig. 51Q ). Measurements ( 1 male , 1 female ).—body w/wings: male 46, female 45; body w/o wings: male 36, female 40; pronotum: male 6.7, female 7.5; tegmen: male 35, female 32; tegmen width: male 12, female 11.5; hind femur: male 19, female 19; ovipositor: female 22.5 mm .

Description. Medium sized to large species. Head: Face ovoid; forehead in middle with fine riffles, laterally nearly smooth; fastigium verticis wider than scapus; ocelli distinct; fastigium frontis separated from fastigium verticis by a very fine suture; subocular furrows shallow ( Fig. 48D ). Abdominal tergites two and three without stridulatory pegs. Wings surpassing hind knees ( Fig. 46B ). Tegmen: Radius with RS branching before mid-length of tegmen, both forked near tip; media anterior free from base; media posterior arises at about end of basal third of tegmen from equally strong oblique veins from media anterior and cubitus anterior; cubitus posterior undivided, free throughout; with 4 anal veins. 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 about 10–12 external and 17–20 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine; with 3 apical spurs on both sides. Coloration. General color brown; vertex black; pronotum with a broad transverse black band that can be entire or interrupted; legs light medium brown, tarsi darker. Face: Fastigium verticis dark brown with a black spot in middle and yellow ocelli; frons from antennal scrobae and fastigium frontis downward black except for median ocellus yellow, a pair of large spots below antennal scrobae and an area around clypeo-frontal suture dark red brown, ventral margin and midline of clypeus and very base of labrum yellow; labial palpi yellowish, maxillary palpi black. Tegmen semi-transparent yellowish, towards base darker; veins yellow; hind wing semi-transparent ochre, main veins yellow or brown, cross veins dark brown or black adorned on both sides by narrow light or dark brown bands. Male. Eighth abdominal tergite prolonged. Ninth abdominal tergite globular, furrowed in midline, then split and provided at both sides with a large, compressed, curved, acute process, in situ overlapping each other; the process is little shorter and thicker than in the nominate subspecies. Tenth abdominal tergite present ( Fig. 49C ). Subgenital plate wider than long with diverging lateral margins, apical margin faintly concave in middle; styli stout, almost twice as long as subgenital plate, inserted at apico-lateral angles; without v-shaped depression. Phallus membranous. Female unknown. Measurements ( 3 males ).—body w/wings: 47–49; body w/o wings: 31–40; pronotum: 6.5–7.0; tegmen: 33–35; tegmen width: 12.5; hind femur: 19–20; antenna: 95–100 mm .

Discussion. C. erythrocephala borealis is close to C. martha ( Griffini, 1914a ) . Gorochov et al . (2015) selected a lectotype (male) for the latter species since Griffini's original type is lost. They supposed that Griffini's type (type locality Annam ) must have been from Laos rather than Vietnam . The neotype is from Banday, Laos , and the authors do not expect that species to occur in Vietnam . The specimen from North Vietnam at hand is similar to the neotype of C. martha , it has some distinct differences of color pattern of head and pronotum, the black pattern being more extended in C. martha than in C. borealis , and shape of tegmen (length to greatest width index 2.3 in C. martha , 3.0 in C. borealis ) that makes it unlikely that both specimens belong to the same species. From C. erythrocephala Gorochov, 2003 described from South Vietnam C. borealis differs apart from distinctly larger size by the shape of the female subgenital plate that has the central area elevated especially in posterior area and the lateral areas in basal half depressed and flattened instead of with transverse furrow (or elevation) in C. erythrocephala , the apical margin is straight to little convex instead of faintly notched in middle, and the groove at very base is very small instead of large. Additional Description. Large species. Head: Face ovoid; forehead in middle with fine transverse riffles and scattered impressed dots, laterally nearly smooth; fastigium verticis little wider than scapus; ocelli distinct; fastigium frontis separated from fastigium verticis by a fine suture; subocular furrows indistinct ( Fig. 48I ). Abdominal tergites two and three without stridulatory pegs. Wings surpassing hind knees ( Fig. 46G ). Tegmen: Radius and RS both forked near tip; RS on left tegmen only with a second unforked branch; media anterior arises free from base; cubitus anterior at base with a single branch that forks into two veins, the anterior branch makes a curvature and receives an oblique connection vein from MA and shortly after divides again into two parallel branches, MP and CuA1, while the posterior branch (CuA2) does not divide further; as individual variation the anterior branch remains undivided as MP+CuA1; cubitus posterior undivided, free throughout; with 4 anal veins, the last two with common base. 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. Coloration. General color light brown; pronotum with a broad, curved, black band that not completely reaches the anterior margin and that includes four light dots; rhombic area in front of that band brown, posterior area yellowish brown, rim blackish. Face light brown; genae, mandibles and ventral area of labrum black. Tegmen semi-transparent yellowish, towards base darker; veins yellow or brown, in middle and especially towards base cross-veins bordered by very narrow black bands on both sides; hind wing semi-transparent light brown, towards margin ochre; main veins yellow to brown; cross veins brown near margin, but mostly black and bordered on both sides by brown bands. Male unknown. Female. Seventh abdominal sternite of normal size but in contrast to preceding sternites not setose but surface granular with only few scattered setae. Subgenital plate in middle of anterior margin with a small pit; at base broad with lateral marginal areas angularly upcurved, afterwards with convexly converging margins, apex rounded; surface rugose ( Fig. 51R ). Ovipositor elongate, very slightly curved with little converging margins; before tip margins more strongly narrowing, tip subobtuse ( Fig. 51S ). Measurements ( 1 female ).—body w/wings: 60; body w/o wings: 38; pronotum: 9.5; tegmen: 45; tegmen width: 15; hind femur: 26.5; antenna: 150; ovipositor: 27.5 mm .