Xenogryllus Bolívar, 1890

Jaiswara, Ranjana, Dong, Jiajia, Ma, Libin, Yin, Haisheng & Robillard, Tony, 2019, Taxonomic revision of the genus Xenogryllus Bolívar, 1890 (Orthoptera, Gryllidae, Eneopterinae, Xenogryllini), Zootaxa 4545 (3), pp. 301-338 : 304-306

Xenogryllus Bolívar, 1890

Type species: Xenogryllus eneopteroides Bolívar, 1890 . Xenogryllus Bolívar, 1890: 232 ; Kirby 1906: 106; Chopard 1968: 349; 1969: 307; Vasanth 1993: 130; Robillard & Desutter- Grandcolas 2008: 67; Cigliano et al. 2018 ( Orthoptera Species File Online); Jing et al. 2018: 274 (Chinese Xenogryllus ).

Synonym names:

Dindymus Kirby, 1906: 88 —incorrect spelling of Dionymus .

Dionymus Brunner von Wattenwyl, 1893: 213 — Chopard 1968: 349.

Emended diagnosis. Genus of average to large size, differing from Pseudolebinthus by FWs as long or longer than abdomen in both sexes (shorter in Pseudolebinthus ), hind wings longer than FWs, forming a short tail posterior to FWs. Eyes small and little prominent, located on face. Face with a whitish or yellowish mask with dark spots. FIII long and thin. Male. Dorsal disc of pronotum forming a wide trapezoid. FWs almost completely overlapping, widened basally, usually forming a characteristic box around abdomen, twice as wide as abdomen. FW cells with thin longitudinal wrinkles, including harp and mirror, absent in Pseudolebinthus . Left and right FWs similar in sclerotization and coloration (asymmetrical in Pseudolebinthus ). Male genitalia: Pseudepiphallic sclerite longer than rami; lophi long and sclerotized (shorter in Pseudolebinthus ). Lophi with apical hook-like inner expansions. Pseudepiphallic sclerite with lateral membranous lobes. Rami strong and short, their apex convergent and hooklike. Female. Dorsal disc of pronotum almost rectangular. FWs as long as in male, not widened, reaching apex of abdomen. Ovipositor flattened longitudinally as in other eneopterine genera, its apex rounded and smooth. Female Copulatory papilla long, thin and conical.

Redescription. Genus of average to large size ( Figs 1–2 ), generally light brown to ochre, with a few dark patterns on FWs. Vertex with five wide longitudinal dark bands ( Fig. 4 ), including a wide median one prolonged on fastigium, two lateral bands more or less marked, made of aggregates of brown dots, and two thin stripes posterior to eyes. Eyes rather small, little prominent, ornamented with thin dorso-ventral dark stripes. Fastigium forming a wide rectangular rostrum slightly prominent on face. Scapes yellow with brown patterns, antennae light brown. Face with a whitish mask with dark spots ( Fig. 3 ). Lateral part of head and lateral lobes of pronotum almost homogeneously brown. Legs brown. TI with two tympana; inner tympanum covered by a sclerotized expansion, its membrane visible along a small longitudinal slit only; outer tympanum oval in shape, its surface smooth. TI with three apical spurs; outer dorsal apical spur absent. TII with four apical spurs (two dorsal and two ventral). FIII long and thin; TIII with four outer and four inner sub-apical spurs.

Male. Dorsal disc of pronotum forming a wide trapezoid. FWs almost completely overlapping, widened basally, forming a wide box around abdomen ( Fig. 5 ), with glandular structures on metanotum ( Fig. 6 ). FW cells with thin longitudinal wrinkles. Left and right FWs similar in sclerotization and coloration. FWs light brown, translucent, with the following pattern of black spots on dorsal field: wide black transverse band anterior to transverse part of 1A, including file angle in some species; four corners or mirror and median area of chords with faint dark markings ( Fig. 5 ). Harp with two complete parallel oblique veins and one incomplete oblique vein between diagonal vein and first complete oblique; harp distal angle concave. Mirror large and rounded, separated in two sub-equal parts by a sinuous accessory vein. Cell d2 crescent-like, thin and underlying mirror. Cell e1 very long and curved, underlying posterior margin of mirror. Apical field well developed, triangular, including 4–5 cell alignments. Lateral field crossed by numerous parallel branches of Sc.

Male genitalia ( Fig.7 ): Pseudepiphallic sclerite longer than rami; pseudepiphallic lophi very long and sclerotized, with apical hook-like inner expansions ( Fig. 8 ). Pseudepiphallic sclerite with lateral membranous lobes. Membrane at bases of pseudepiphallus forming a sclerotized plate; basal margin with a ventral reinforcement. Rami usually strong with convergent hook-like apex; most often with a ventral posterior expansion reaching base of pseudepiphallic membranous lateral lobes. Pseudepiphallic parameres with one strong rectangular ventral lobe covered with scale-like reliefs, with a basal lobe mostly membranous. Ectophallic arc nearly membranous. Ectophallic apodemes usually strong. Ectophallic ventral expansions well developed and sclerotized. Ectophallic fold entirely sclerotized ventrally, its lateral expansions partly fused with lateral arms of endophallic sclerite. Endophallic sclerite forming a flat plate with long latero-posterior arms and a short medio-posterior triangular expansion. Endophallic apodeme with two wide lateral lamellas and no dorsal crest.

Female. Pronotum dorsal disc almost rectangular. FWs as long as in male, reaching apex of abdomen or slightly longer, not widened as in male; light brown with a dark spot of variable size between veins CuP and CuA, near lateral angle, at ¼ of FW length; with strong longitudinal veins and faint transverse ones. Lateral field crossed by numerous parallel branches of Sc; area between R and Sc most often with a thin dark brown band. Subgenital plate variably indented apically ( Fig. 9 ). Ovipositor flattened longitudinally, its apex rounded and smooth ( Fig. 10 ). Female copulatory papilla: long, thin and conical, its sclerotization variable ( Fig. 11 ).

Distribution. Japan, Southern China, Taiwan, India, Sri Lanka, Thailand, Myanmar, Vietnam, Bangladesh and Sub-Saharan Africa.

Natural history. Xenogryllus species live in open areas, in grassland and savannah. Males sing at night from low bushy vegetation.

Figures

FIGURE 1. (A–C) Xenogryllus eneopteroides: male in dorsal (A) and lateral (B) views, female in dorsal view (C); (D–G) Xenogryllus marmoratus: male in dorsal (D) and lateral (E) views, female in dorsal (F) and lateral (G) views; (H–I) Xenogryllus lamottei n. sp.: male holotype in dorsal (H) and lateral (I) views; (J–K) Xenogryllus maniema n. sp.: male paratype in dorsal (J) and lateral (K) views; (L–O) Xenogryllus maichauensis: male in dorsal (L) and lateral (M) views, female in dorsal (N) and lateral (O) views. Scale bar: 1 cm.

FIGURE 2. (A–D) Xenogryllus mozambicus n. sp.: male in dorsal (A) and lateral (B) views, female in dorsal (C) and lateral (D) views; (E–H) Xenogryllus transversus: male in dorsal (E) and lateral (F) views, female in dorsal (G) and lateral (H) views; (I–L) Xenogryllus ululiu: male in dorsal (I) and lateral (J) views, female in dorsal (K) and lateral (L) views. Scale bar: 1 cm.

FIGURE 3. Heads of Xenogryllus in facial (left panel) and lateral views (right panel): (A–B) Xenogryllus eneopteroides; (C–D) Xenogryllus lamottei n. sp.; (E–F) Xenogryllus maichauensis; (G–H) Xenogryllus maniema n. sp.; (I–J) Xenogryllus marmoratus. (K–L); Xenogryllus mozambicus n. sp.; (M–N) Xenogryllus ululiu; (O–P) Xenogryllus transversus. Scale bar: 1 mm.

FIGURE 4. Heads of Xenogryllus in dorsal views: (A) Xenogryllus eneopteroides; (B) Xenogryllus lamottei n. sp.; (C) Xenogryllus maichauensis; (D) Xenogryllus maniema n. sp.; (E) Xenogryllus marmoratus; (F) Xenogryllus transversus; (G) Xenogryllus ululiu; (H) Xenogryllus mozambicus n. sp. Scale bar: 1 mm.

FIGURE 5. Male FW venation in dorsal view: (A) Xenogryllus eneopteroides; (B) Xenogryllus lamottei n. sp.; (C) Xenogryllus maichauensis; (D) Xenogryllus maniema n. sp.; (E) Xenogryllus marmoratus; (F) Xenogryllus mozambicus n. sp.; (G) Xenogryllus transversus; (H) Xenogryllus ululiu. Scale bar: 5 mm.

FIGURE 6. Male metanotal glandular structures in Xenogryllus eneopteroides: (A) glandular pit (drawing by G. Hodebert (MNHN) modified from Robillard & Desutter-Grandcolas 2004b), (B–C), SEM view of glandular pores on scutum. Scale bars: 1 mm (A), 10 µm (B), 1 µm (C).

FIGURE 7. Male genitalia: (A–C) Xenogryllus eneopteroides, dorsal (A), ventral (B) and lateral (C) views; (D–E) Xenogryllus lamottei n. sp., ventral (D), lateral (E) views; (F–G) Xenogryllus maniema n. sp., ventral (F), lateral (G) views; (H–I) Xenogryllus marmoratus, ventral (H), lateral (I) views; (J–K) Xenogryllus mozambicus n. sp., ventral (J), lateral (K) views; (L– N) Xenogryllus maichauensis, pseudepiphallic lophi in ventral (L–M) and lateral (N) views, male from South China (L), male from Thailand (M, N); (O–P) Xenogryllus transversus, dorsal (O), ventral (P) views; (Q–R) Xenogryllus ululiu, pseudepiphallic lophi in dorsal (Q) and ventral (R) views. Scale bar: 1 mm.

FIGURE 8. Right pseudepiphallic lophi of male genitalia in dorsal view: (A–B) Xenogryllus eneopteroides, male from Central African Republic (A), male from Ivory Coast (B); (C) Xenogryllus lamottei n. sp.; (D) Xenogryllus maichauensis; (E) Xenogryllus maniema n. sp.; (F) Xenogryllus mozambicus n. sp.; (G) Xenogryllus marmoratus; (H) Xenogryllus ululiu; (I) Xenogryllus transversus. Symbols: Preapical hook-like expansion figured in gray or with a black arrow; dotted parts represent membranous areas; thin lines represent folds and reliefs in sclerites. Scale bar: 1 mm.

FIGURE 9. Apex of female subgenital plate and base of ovipositor in ventral view: (A) Xenogryllus eneopteroides; (B) Xenogryllus marmoratus; (C) Xenogryllus maichauensis; (D) Xenogryllus mozambicus; (E) Xenogryllus transversus; (F) Xenogryllus ululiu. Scale bar: 1 mm.

FIGURE 10. Apex of female ovipositor: (A) Xenogryllus eneopteroides; (B) Xenogryllus maichauensis. Scale bar: 1 mm.

FIGURE 11. Female copulatory papilla: (A–B) Xenogryllus eneopteroides, in ventral (A) and lateral (B) views; (C–D) Xenogryllus marmoratus, in ventral (C) and lateral (D) views; (E–G) Xenogryllus maichauensis, in ventral (E), dorsal (F) and lateral (G) views; (H–J) Xenogryllus mozambicus n. sp., in ventral (H), dorsal (I) and lateral (J) views; (K–L) Xenogryllus ululiu, in ventral (K) and lateral (L) views; (M–O) Xenogryllus transversus, in ventral (M), dorsal (N) and lateral (O) views. Scale bar: 0.5 mm.