Eulithoxenus emeljanovi Mishchenko, 1968, New record for China 埃氏优岩ỡ

Figs. 1, 10–15

Eulithoxenus emeljanovi Mishchenko, 1968: 295

Redescription. General. Body small. Head frons flat, slightly oblique (Fig. 10A). Fastigium of vertex distinctly wider than scape of antenna. Eyes broadly round and projecting outward. Disc of pronotum both sides with a broadly obtuse concavity on middle part, anterior and posterior margin of pronotum slightly concaved, median carina and posterior transvers sulcus obscure, central transvers sulcus distinctly Chinese characters “八”-shaped, lateral carina faintly indicated; lateral lobes longer than high, with weakly humeral sinus (Fig. 10 BC). Prosternum unarmed (Fig. 10D). Mesosternum with a pair of obtuse triangular lobe-shaped processes, wider than long (Fig. 10D). Metasternum with a pair of obtuse triangular lobe-shaped processes, wider than long (Fig. 10D). Dorsal surface of fore coxae with 1 long spine; length of fore femora about 0.87–0.97 times shorter than pronotum, dorsally and ventrally unarmed, genicular lobes with 0–2 internal spinules and 0–1 external spinules; fore tibiae both sides with a crackshape tympana, dorsally with 3 externally spines and internally unarmed, ventrally with 6 pair of spines, a pair at the apical. Middle femora dorsally and ventrally unarmed, genicular lobes with 1–2 spinules on both sides; middle tibiae dorsally with 4 internal spines and 1–2 external spines, ventrally with 6 pair of spines, a pair at the apical. Hind femora dorsally and ventrally unarmed, genicular lobes with 0–1 spinules on both sides; hind tibiae dorsally with 24–27 spines on both sides and 1 pair of apical spurs, ventrally with 6–10 spines on both sides and 2 pair of apical spurs.

Male. Tegmina brachypterous, about 0.6–0.7 times shorter than pronotum, extending to 2 th abdominal tergite middle part. Left tegmina ventrally with stridulatory file about 35 teeth (Fig. 10J). Right tegmina ventrally with vestigial stridulatory file about 30 teeth (Fig. 10L). Mirror on right tegmina pentagonal, slight longer than wide (Fig. 10 KL). Hind wings rudimentary (Fig. 10F). Middle part of 10 th abdominal tergite with a pair of obtuse lobes on posterior margin, furrow between lobes narrowly. Epiproct hidden under 10 th abdominal tergite lobes. Cercus hirsute, broad and flat, subbasal part with a raised ruffle; apex short and obtuse; inner margin most part with a broad inner tooth; inner tooth lager and wide, strongly recurved; inner margin near straight, outer margin arcuate; apical part suddenly narrow with an acute apex. Subgenital plate length slightly shorter than width, with lateral carinae, middle part of posterior margin with a triangular excision, styli short (Fig. 11C). Titillators broad at basal arms; apical arms outer margin bearing two rows denticles, with obtuse apex (Fig. 11E).

Female. Tegmina brachypterous, extending to 1 th abdominal tergite anterior margin, almost invisible in dorsal view (Fig. 10 GH). Cercus conical and pileous. Posterior margin of 10 th abdominal tergite with a median narrow notch (Fig. 11F). 7 th abdominal sternite with a strong round hump. Subgenital plate wider than length, with a median hourglass hump, middle of posterior margin with a deep angle concave (Fig. 11G). Ovipositor shorter than hind femora, distinctly upcurved (Fig. 11H).

Coloration. Body laterally and dorsally generally whitish gray and yellowish, with dark brown or black marmoration, ventrally whitish. Eyes white with dark brown spots. Lower and hind margin of pronotum lateral lobes whitish gray with dark brown spots. Tegmina orange with dark brown spots. Spines of fore and middle leg black, hind leg spines black at apex, hind femora middle part with a black spot on both sides. Male cercus inner tooth black. Ovipositor apical part black.

Variations. Very few individual bodies laterally and dorsally generally reddish orange, except the black spot on hind femora middle part, without distinctly spots.

Measurements(mm). Body (from head to tip of abdomen): ♂ 17.43–18.55, ♀ 20.54; pronotum: ♂ 4.50–4.78, ♀ 5.15; tegmina: ♂ 2.90–3.37, ♀ 0.88; mirror of right tegmina (from fore to hind): ♂ 1.93; fore femora: ♂ 4.00–4.30, ♀ 4.50; middle femora: ♂ 4.76–5.12, ♀ 5.50; hind femora: ♂ 16.74, ♀ 18.28; fore tibiae: ♂ 5.15–5.40, ♀ 6.12; middle tibiae: ♂ 5.60–6.50, ♀ 6.73; hind tibiae: ♂ 15.20–15.76, ♀ 17.11; male titillators (straight-line distance from base to end): 0.88; ovipositor: 12.88.

Material examined. 2♂ 1♀, Beiwudang National Park, Dawukou District, Shizuishan city, Ningxia Hui Autonomous Region, China (106°19'52.70"E, 39°3'7.48"N, alt. 1223m), 7-vii-2020, leg. Tong Lou.

Remarks. Eulithoxenus emeljanovi differs from Eulithoxenus mongolica (Uvarov, 1928) by: posterior margin of male 10 th abdominal tergite with a pair of obtuse lobes, which have an extremely narrow furrow; male cercus broad and flat, apex short and obtuse, inner margin most part with a broad inner tooth; posterior margin of female 7 th abdominal sternite without notch. Based on the photos of type specimen in OSF and description of E. mongolica (Cigliano et al. 2021; Storozhenko 2004; Uvarov 1928), male 10 th abdominal tergite concave widely and without lobes; male cercus slightly incurved, inner tooth near the apex, short and acute, directed obliquely towards the base; posterior margin of female 7 th abdominal sternite with a notch. We concluded that the two species may not belong to the same genus, and furthermore specimens need to be checked to find out their relationships.

Songs. The adults make calling songs at night. The song consists of echemes with syllables. Each echeme consist two syllables, echeme duration for 80–100 ms, echeme interval for 240–300 ms. Each syllable duration for 30–50 ms, syllables interval for 10–20 ms.

Distribution. Mongolia; Tuva; China (Ningxia).