Xenogryllus ululiu Gorochov, 1990

(Figs 2 I–L, 3M–N, 4G, 5H, 7Q–R, 8H, 9E, 11K–L, 12E, 18)

Xenogryllus ululiu Gorochov, 1990: 14 — Gorochov 1992: 10; Kim & Pham 2014: 60; Robillard et al. 2007: 1267 (song frequency); Cigliano et al. 2018 ( Orthoptera Species File Online) Jing et al. 2018: 274.

Type material. Holotype, ♂, Vietnam: Gia Lai, Kannack, A.V. Gorochov (ZIN) [not examined] . Paratype (16), Vietnam: Gia Lai, Kannack, A.V. Gorochov: 8–16. ii.1988, 1 ♂ (MNHN-EO-ENSIF2809) [examined] .

Additional material examined. Vietnam: Gia Lai, 2.ii.1993, 1♀, identified Xenogryllus ululiu by A.V. Gorochov, molecular sample XulV (MNHN-EO-ENSIF2810); 7. XI.1993, 1 ♂, molecular sample XulV2, A.V. Gorochov. Thailand: 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 0291XENO.WAV, mixed Oak-Pine forest, grassy undergrowth, Bamboo thicket [day collecting and night collecting following stridulation], identified Xenogryllus ululiu by S. Ingrish, molecular sample XulTh (ZFMK) . Loei, NamNao NP at night, 13(14.ix.1989, S. Ingrisch, 1♂, identified Xenogryllus ululiu by S. Ingrish, molecular sample XulTh (ZFMK) . Cambodia: Kampong Spoe, northern part of Elefan mts [Dâmrei Mountains], Kiri-Rom National Park, 130 km NNE Sihanoukville, 300–500m, 27.ix–1.x.2003, A. Gorochov, M. Berezin, 1♂, molecular sample X21 - XulCam 2, 1♀ (ZIN) . Kaoh Kong, central part of Elefan mountains [Dâmrei Mountains], vill. Styeng-Chkhral (100 km NE of Sihanoukville), 300–500m, 27.viii–6.ix.2003, A. Gorochov, L. Anisyutkin, 1♂, molecular sample X20 - XulCam 1 (MNHN-EO-ENSIF4385), 1♂ (ZIN) . Campot, environs of Sihanoukville (= Kampong Som), 14–21.ii.1998, A.V. Gorochov, 1♀ (ZIN) . Sihanoukville, citi near Siam bay, environs, 22–26.VIII.2003, A. Gorochov, L. Anisyutkin, 1♂, molecular sample X19 - XulSi (ZIN) . China: Guangdong, Shenzhen District, Wutongshan Mt., 21.ix.2014, coll. Zhang Tao, 5♂, 3♀, (SNNU) .

Type locality. Vietnam, Gia Lai, Kannack .

Distribution. Vietnam, Thailand, Cambodia, Southern China.

Emended diagnosis. Species of average to large size, close to X. transversus and X. maichauensis in terms of shape and coloration, from which it differs by smaller size, mirror slightly wider than long (less rounded than in in X. transversus and X. maichauensis), and male genitalia looking like a stockier version of that of X. transversus, with pseudepiphallic lophi basally fused together (Fig. 8H), with a sharp posterior apex and a strong dorsal hooklike expansion. In females, head larger than in other species, wider in dorsal view than rest of body.

Redescription. In addition to the characters of the genus, X. ululiu has an average size and a light brown or golden brown coloration (Fig. 2 I–L). Head (Fig. 3 M–N): Fastigium slightly widened apically, as in X. transversus and X. maichauensis (Fig. 4G); eyes rather small, restricted to the dorsal third of head in lateral view (Fig. 3N). Pronotum dorsal disc with a wide median black longitudinal band, its lateral angles not carinated, with a thin yellow band underlined by a black line ventrally. Hind wings tail gray brown, near twice as long a pronotum.

Male. FW venation (Fig. 5H): 1A forming a straight angle. Dark coloration anterior to 1A not including angle of file. Harp wide, with one short incomplete oblique vein and two complete ones slightly bisinuate. Mirror large, slightly wider than long, less rounded than in X. maichauensis and X. transversus, its inner margin curved as in these species. Apical field forming a triangle longer than wide, with 6–7 (n = 5) cell alignments.

Male genitalia (Fig. 7 Q–R): Pseudepiphallic lophi stocky, basally fused together, with a sharp apex and a strong dorsal preapical expansion (Fig. 8H). Rami strong, convergent apically. Ectophallic apodemes strong, lamellate apically. Ectophallic fold and endophallic sclerite almost fused, forming a long ventral gutter, trifurcate posteriorly and extended anteriorly between rami. Endophallic apodemes made of anterior lateral lamellas.

Female. Head larger than in male (Fig. 2 K–L), wider than rest of body in dorsal view. Dorsal disc of pronotum almost rectangular, its posterior margin slightly bisinuate. FWs light brown, anterior dark spot small. Dorsal field with nine strong longitudinal veins. Subgenital plate with a wide, apical U-shaped indentation with sharp edges (Fig. 9E). Ovipositor as long as FIII.

Female genitalia: Copulatory papilla small, conical, its apex rounded and sclerotized (Fig. 11 K–L).

Life history traits. According to S. Ingrish who recorded the species’ call in Thailand, males of X. ululiu sing at night in grassy undergrowth of mixed Oak-Pine forest or bamboo thicket (Cigliano et al. 2018).

Calling song (Figs 12E, 18). One male from Thailand was recorded by S. Ingrish at 21°C. The song consists of echemes during 566 ± 57 ms, with a period of 2041 ± 358 ms. Echemes are made of 4 or 5 syllables (m=5), with syllable duration = 108 ± 3.8 ms and syllable period = 120.3 ± 3 ms. Within echemes, the three starting syllables have a lower amplitude than the final 1–2 syllables. Dominant frequency is 4.8 ± 0.4 kHz and corresponds to the fundamental frequency of the spectrum.

Measurements. See Table 9.