Xenogryllus maichauensis Gorochov, 1992

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 : 315-323

Xenogryllus maichauensis Gorochov, 1992

( Figs 1 L–O, 3E–F, 4C, 5C, 7L–N, 8D, 9C, 10B, 11E–G, 12A, 13)

Xenogryllus maichauensis Gorochov, 1992: 9 —Kim & Pham 2014: 60; Cigliano et al. 2018 ( Orthoptera Species File Online); Jing et al. 2018: 274.

Xenogryllus transversus — Yin & Liu 1995: 96; Robillard et al. 2007: 1267 (song frequency, wrong identification); He 2018: 516; Cigliano et al. 2018 ( Orthoptera Species File Online) (wrong identification).

Type material. Holotype, ♂, Vietnam: Mai Châu ( ZIN) [examined].

Additional material examined. China: Yunnan , Mengla, E101°33’ N21°28’, 3.ix.1991, Zuyao Liu, Tianqi Wang & Heisheng Yin : 1♂ (14062446), 2♀ (14062547, 14062622) (SIPPE). Mengla Distr. , 12–23.x.2014, coll. Zhang Tao, 14♂, 2♀, ( SNNU) . San Chahe, Mongyang, E98°22’ N25°23’, 31.vii.1995, Xianwei Liu , Weinian Zhang , Xingbao Jin , 1♂ (14062620) ( SIPPE) . Xi Shuang Ban Na, 580 m, 10.ix.1993, Xinyue Chen , 3♂, (14064963, 14064964, 14064966); 2♂, 7.ix.1993 (14064968, no number); 1♂, 5.ix.1993 (14064967) ( SIPPE) . Monglun Xi Shuang Ban Na, E101°15’ N21°56’, 5.ix.1993, Longlong Yang, 2♀, (14064969, 14064971); 7.ix.1993, Xinyae Chen , 1♀ (14064970) ( SIPPE) . Jinhong, E 101°15’ N21°56°, Zuyao Liu, Tianqi Wang , Heisheng Yin : 6.ix.1991, 3♂ (14062619, 14062546, 14062448); 8.ix.1991, 1♂ (14062447) ( SIPPE) . Jinghong, [N22°0'6.97" 100°46'25.07"E], 9.ix.1991, Zuyao Liu, Tianqi Wang , Heisheng Yin , 1♀ (14062449) ( SIPPE) . Mohan Vill. , 950 m, 3-ix.2005, coll. Xue Guoxi, 2♂ ( NWAFU) . Guangdong, Shen zhen, [22°33'59.69"N, 114° 2'25.53"E], 9.x.2012, Zhang Tao [online photograph] . Thailand: Tak, Doi Musoe, 700 m, Agric. Res. Stn at night, 9.x.1990, S. Ingrish : 1♀, 1♂, molecular sample XtrTh, identified Xenogryllus transversus by S. Ingrish ( ZFMK) . Mae Salid, Monkrathing, 17°30' N, 98°5' E, 700 m, 19.ix.1989 – 21.ix.1989, S. Ingrisch , 1♂, mountain forest and agricultural land [day collecting and night collecting following stridulation, Stridulation recorded by S.Ingrisch 0295DXEN.WAV [old ID CIGxentraSW03], identified Xenogryllus transversus by S. Ingrish ( ZFMK) . Umphang, 1–6 km S., 15° 59' N, 98° 50' E, 16.x.1991, S. Ingrisch , 1♂, bamboo forest, along road and trails, stridulation recorded by S. Ingrisch 0510XENO.WAV, identified Xenogryllus transversus by S. Ingrish ( ZFMK) . Chiang Mai, Roadside bw Samoeng and Mae Rim , 18°50'N, 99°0°, 1♂, 11.x.1991, S. Ingrisch , 1♂, stridulation recorded by S. Ingrisch 0502XENO.WAV, [old ID CIGxentraSW05], roadside at night, identified Xenogryllus transversus by S. Ingrish ( ZFMK) . Petchabun, Nam Nao, 16°47'N, 101°27'O, 1000 m, S. Ingrisch; 13.ix.1989 – 14.ix.1989, S. Ingrisch, 1♂, stridulation recorded by S. Ingrisch 0286XENO.WAV [old ID CIGxentraSW01], mixed Oak-Pine forest , grassy undergrowth, Bamboo thicket [day collecting and night collecting following stridulation], identified Xenogryllus transversus by S. Ingrish ( ZFMK) .

Type locality. Mai Châu , Vietnam .

Distribution. Southern China, Northern Vietnam and Northern Thailand.

Emended diagnosis. Species of large size, similar in size, venation and coloration to X. transversus , from which it differs mostly by male genitalia, with pseudepiphallic lophi forming curved elongate hooks widened apically ( Fig. 8D ), while lophi are straight in X. transversus ( Fig. 8I ).

Redescription. In addition to the characters of the genus, X. maichauensis has a large size and a light brown or golden coloration ( Fig. 1 L–O). Fastigium slightly widened apically as in X. ululiu and X. transversus ( Fig. 4C ). Eyes rather small, located on face, restricted to the dorsal third of head in lateral view ( Fig. 3 E–F). Lateral angle of dorsal disc of pronotum not carinated, with a thin yellow band underlined by a thin black line anteriorly. Hind wings tail gray brown, twice as long as pronotum.

Male. Pronotum dorsal disc more rectangular than in X. transversus , with a wide black median longitudinal band, its posterior margin slightly bisinuate. FW venation ( Fig. 5C ): 1A forming a straight angle, with 299 stridulatory teeth (n=1) located on transverse part of 1A. Dark coloration anterior to 1A not including angle of file. Harp wide. Mirror large, well-rounded, its inner limit curved. Apical field forming a triangle longer than wide, with six cell alignments.

Male genitalia ( Fig. 7 L–N): Characteristic Y-shaped pseudepiphallic lophi forming curved elongate hooks, widened apically, with a sharp dorsal preapical expansion ( Fig. 8D ). Rami strong, convergent apically, with a ventral posterior expansion reaching base of pseudepiphallic lateral membranous lobes. Ectophallic apodemes long and thin. Ectophallic fold and endophallic sclerite almost fused, forming a wide sclerotized plate, trifurcate posteriorly; endophallic apodemes made of wide lateral lamellas.

Female: Head slightly wider than pronotum, with strong jaws visible from dorsal view ( Fig. 1 N–O). Dorsal disc of pronotum almost rectangular, its posterior margin slightly bisinuate. FWs light brown, anterior dark spot larger than in X. ululiu , X. transversus and X. marmoratus . Dorsal field with nine strong longitudinal veins. Subgenital plate with a V-shaped apical indentation with rounded edges ( Fig. 9C ). Ovipositor ( Fig. 10B ) as long as FIII.

Female genitalia: Copulatory papilla ( Fig. 11 E–F) conical, its apex rounded and sclerotized.

Life history traits. In Vietnam, the type specimens were found in forest, on leaves of bushes near a stream (A. Gorochov, pers. comm.). According to the information associated with the recordings made by S. Ingrish in Thailand available on the Orthoptera Species Files online under the name X. transversus ( Cigliano et al. 2018) , the species was found in mixed oak-pine forest on grassy undergrowth with bamboo thicket. Males call at night on vegetation.

Calling song. ( Figs 12A , 13 ) X. maichauensis was recorded in Thailand by S. Ingrish ( Cigliano et al. 2018). At 24.5°C, the calling song is made of short echemes quickly repeated and composed of 2–4 long syllables (m = 3.02 ± 0.63), lasting for 179.5 ± 41.6 ms, with a period of 502 ± 42 ms. Within echemes, the first syllable has a lower amplitude than the next ones. Syllables are rather long (duration = 46.5 ± 1.7 ms) with a syllable period of 65.1 ± 1.7 ms (syllable duty cycle = 71%). The frequency spectrum shows a dominant frequency at 4.91 ± 0.07 kHz followed by two powerful harmonics.

Measurements. See Table 4.

Taxonomic discussion. The male genitalia of the specimen from Thailand shows slightly different pseudepiphallic lophi compared to the holotype from Vietnam and examined males from China, with more straight apical branches and less globular apex ( Fig. 7 L–M). Such differences are however based on too few observations to characterize a new species.

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 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 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.

FIGURE 12. Comparison of calling songs, oscillogram of five echemes: (A) Xenogryllus maichauensis; (B) Xenogryllus marmoratus; (C) Xenogryllus mozambicus n. sp.; (D) Xenogryllus transversus; (E) Xenogryllus ululiu. Scale bar: 1 s.

FIGURE 13. Calling song of Xenogryllus maichauensis: (A) oscillogram of 5 echemes; (B) detailed oscillogram (upper panel) and sonogram (lower panel) of 1 echeme; (C) frequency spectrum.