Definition: Members of the Hingstoniella group have a more-or-less-developed modified vertex in the male, and share a strongly constricted base of the aedeagus, this type of aedeagus seems to be unique in Batrisitae.

Included taxa: Hingstoniella, Sinotrisus, and Besuchetaceus gen. n.

Hingstoniella Jeannel, 1960: 410. Type species: Hingstoniella lata Jeannel (original monotypy).

Hingstoniella: Newton & Chandler, 1989: 37 (catalog); Yin, Li & Zhao, 2011: 390 (diagnosis, redescription, illustrations).

Diagnosis: Head triangular; frontal rostrum low; with punctiform vertexal foveae; antennomeres XI elongate and conical. Pronotum transversely octagonal, with only punctiform lateral antebasal foveae; lacking antebasal spines. Elytra each with one large basal fovea and shallow discal stria. Abdomen with lateral margins of tergite IV edged by marginal carinae; tergite IV longest.

Redescription: General body form robust; Length 3.09-3.56 mm. Head triangular (Fig. 1A); with low frontal rostrum, antennal tubercles low; vertexal foveae small and punctiform, connected by indistinct U-shaped vertexal sulcus; antennae with 11 antennomeres, clubs formed by apical three antennomeres, antennomeres XI elongate and conical; ocular-mandibular carinae faint; eyes reniform (Fig. 1B); maxillary palpi with palpomeres III transverse and triangular, IV fusiform; with gular foveae merged into single opening (Fig. 1C). Pronotum (Fig. 1D) transversely octagonal; lateral antebasal foveae punctiform, lacking median antebasal fovea and antebasal spines; disc only slightly convex; lacking basolateral foveae; lacking paranotal carinae; lateral procoxal foveae (Fig. 1E) present. Each elytron (Fig. 1F) with one large basal fovea, discal striae shallow, sutural striae complete; lacking subhumeral foveae, marginal stria present from basal one-fourth toward posterior margin; lateroapical notch indistinct. Thorax (Fig. 2A) with small median and lateral mesoventral foveae; with lateral mesocoxal foveae; prepectal foveae present; lateral metaventral foveae punctiform, metacoxae narrowly separated; posterior margin with narrow median notch. Abdomen (Fig. 2B-D) has tergites IV-VI (first to third visible tergites) with marginal carinae extending through tergal length; tergite IV longest, V-VII slightly shorter and subequal in length; tergite IV with basolateral foveae at lateral ends of sulcus, lacking mediobasal foveae and discal carinae, V-VII each with one pair of basolateral foveae. Sternite IV (second visible ventrite) twice length of V at midlength, with one pair of mediobasal foveae and three pairs of basolateral foveae, lacking basal sulcus, V-VII lacking foveae. Legs short, second and third tarsomeres subequal in length.

Male (Fig. 3A-B) with vertex modified. Aedeagus with paramere fused to median lobe to form elongate ventral lobe; articulated dorsal lobe present; basal capsule with strongly constricted base.

1 Vertexal modification composed of indistinct punctiform protuberance (Fig. 4A); each eye with more than 60 facets; protibiae with mesal margins angularly expanded near apex (Fig. 4C). Distribution: Nepal, Tibet, northern India (Fig. 12) H. lata Jeannel

– Vertexal modification composed of distinct triangular bump (Fig. 7A); each eye with about 40 facets; protibiae with mesal margins less expanded (Fig. 7C). Distribution: Nepal (Fig. 12) H. trigona sp. n.

Comparative notes: The genus up on which the Hingstoniella group is based. Members of the group share a modified vertex in the male, and a strongly constricted base of the aedeagal basal capsule. Hingstoniella can be quickly separated from Sinotrisus and Besuchetaceus gen. n. by the transversely octagonal pronotum, and each elytron with single basal fovea, while both latter genera have the pronotum slightly transverse or slightly longer than wide, and have three basal foveae on each elytron.

Hingstoniella lata Jeannel, 1960: 410. Type locality: Sikkim, Lachen, alt. 3000 m.

Hingstoniella lata. – Yin et al., 2011: 395 (description, new locality, host record).

Material examined: (23 ♂♂, 23 ♀♀). CHINA (in SNUC): 3 ♂♂, 1 ♀, labeled ‘China: Xizang A. R., Neilamu Co., Quxiang (曲乡), alt. 3300 m, nest of Myrmica sp. under rock, 20.vii.2010, Wen-Xuan Bi leg. [1 ex Myrmica each pinned under two males]’. – 1 ♂, 1 ♀, labeled ‘China: Xizang A. R., Yadong Co., Xiayadong (下亚东), alt., 3400 m, nest of Myrmica sp. under rock, 9.viii.2010, Wen-Xuan Bi leg. [1 ex Myrmica pinned under a male]’. – 2 ♂♂, 2 ♀♀, same locality, except 8.viii.2010, 2800 m [1 ex Myrmica pinned under a male]’. – NEPAL (in MHNG): 1 ♂, labeled ‘Thodung via, Those 3100 m, 29.-31.5.1976 / Nepal, W. Wittmer, C. Baroni Urbani / comparé au type / Hingstoniella lata Jeann. Cl. Besuchet dét. XII. 1977’. – 1 ♀, labeled ‘Pokhara 820 m, 15.-18.6.1976 / Nepal, W. Wittmer, C. Baroni Urbani / Hingstoniella lata Jeann. Cl. Besuchet dét. XII. 1977’. – 1 ♂, labeled ‘NEPAL (Pro. Bagmati), Ridge betw. Mere Dara and Thare Pati, 3500 m, Löbl & Smetana, 9.IV.81 [2 ex. Myrmica pinned under specimen]’. – 1 ♂, labeled ‘Umg, Alm Dugdinma, b. Lughla, 3000-4000 m, Khumbu, Nepal, lg. Franz [Pa263, overleaf] / Hingstoniella, det. D. S. Chandler’. – 5 ♀♀ [on three pins, each pin also with 2x Myrmica], labeled ‘NEPAL (Prov. Bagmati), below Jangtang Ridge, NE Barahbise, 3150 m, Löbl & Smetana, 4.V.81 / Hingstoniella’. – 1 ♀, labeled ‘NEPAL, Khumbu, Periche 4350 m, 29.vi.1963, leg. G. Ebert’. – 1 ♀, labeled ‘NEPAL: Bagmati, Pokhare NE Barahbise, 2800 m, 3.5.81, Löbl - Smetana’. – 3 ♂♂, 2 ♀♀, labeled ‘NEPAL, 9.x.84, Gairi, L. Deharveng’ [according to pers. comm. with L. Deharveng, detail collection data of this material is as following: ‘Nepal: Trekking of Namche Bazar from le Tomba-Kosi: Massif of Hanumante Danda above Jiri. Lieu-dit Gairi, 09/10/84, forest, litter, by hand, Louis Deharveng leg (NEP84-04)’]. – 1 ♀, labeled ‘Gufa-Gorza, 2800-2100 m, 4.VI.1985 / E-Nepal, Koshi, M. Brancucci’. – 1 ♀, labeled ‘E-NEPAL, Dhankuta, Arun Valley, SE des Makalu, Tashigaon, 13.-14.6.1980, leg. C. Holzschuh, 2100 m / 195’. – 3 ♂♂, labeled ‘E Nepal, Koshi, Chauki, 2700 m, Holzschuh, 2.vi.85’ [1 ex Myrmica each pinned under 2 males, 2 ex Myrmica under the other male]. – 2 ♂♂, 2 ♀♀, labeled ‘“Bakan” W of Tashigaon 3200 m, 6.IV.1982, A. & Z. Smetana / NEPAL, Khandbari District’ [1 ex Myrmica each pinned under a male and a female]. – INDIA (in MHNG): 4 ♂♂, 4 ♀♀, labeled ‘INDIA: Darjeeling distr., Tongli, 3100 m, 16.x.1978, I, Löbl, Bes., nr. 16a, under stones’ [1 ex Myrmica each pinned under two males and one female]. – 2 ♂♂, 1 ♀, labeled ‘INDIA - West Bengal Distr. Darjeeling, Tonglu, 16.X.78, Besuchet- Löbl’.

Each of the above specimens bears an identification label as ‘Hingstoniella lata Jeannel, 1960, det. Yin & Li, 2014’.

Description: Male (Fig. 3A). BL 3.20-3.41 mm. Body reddish brown; most part of dorsal surface densely hairy.

Head (Fig. 4A) distinctly transverse, HL 0.55-0.59 mm, HW 0.74-0.84 mm; vertex slightly convex, modification composed of indistinct punctiform protuberance, foveae located below level of posterior margins of eyes; each eye with about 65 small facets; antennal clubs formed by apical three enlarged antennomeres (Fig. 4B). Pronotum transversely octagonal, PL 0.65-0.74 mm, PW 1.02-1.09 mm, median longitudinal sulcus weakly developed. Elytra wider than long, EL 1.02-1.03 mm, EW 1.28-1.31 mm; shallow discal striae extending to 3/4 of elytral length. Metathoracic wings fully developed. Protibiae (Fig. 4C) triangularly projected at mesal margins near apices; mesotrochanters (Fig. 4D) with small protuberance at ventral margin; metatrochanters (Fig. 4E) with ventral margin protruding to form strong projection. Abdomen wider than long, AL 0.98-1.05 mm, AW 1.17-1.20 mm. Aedeagus (Fig. 4F-I) asymmetric, length 0.49-0.52 mm. Female. Similar to male in general appearance, protibiae, mesotrochanters, and metatrochanters lacking protuberance or projection. Each eye with about 45 facets. Tergite VIII (Fig. 4J) and sternite VIII (Fig. 4K) transverse. Genital complex (Fig. 4L) transverse, width 0.37 mm. Measurements: BL 3.09-3.29 mm, HL 0.52-0.55 mm, HW 0.75-0.81 mm, PL 0.66-0.72 mm, PW 1.06-1.08 mm, EL 0.93-1.00 mm, EW 1.06-1.20 mm, AL 0.98-1.02 mm, AW 1.15-1.17 mm.

Differential diagnosis: Hingstoniella lata can be separated from H. trigona sp. n. described below only by the male vertexal modification with an indistinct punctiform protuberance; in contrast, the male of H. trigona has the vertexal modification represented by a much larger, triangular bump.

Intraspecific variation: While the male vertexal modification and other characters on legs are stable, the form of aedeagus of populations from different localities vary distinctly, especially the dorsal lobe in axial view. When available, at least one male from each locality was dissected to illustrate the intraspecific variation (Figs 4F-I, 5, 6).

Biology: Adults of this species were frequently collected from nests of Myrmica ants nesting under rocks.

Distribution: Nepal: Gandaki, Bagmati, Janakpur, Sagarmatha, Koshi; India: Sikkim, West Bengal; China: Xizang (Fig. 12).

Holotype: Holotype ♂, NEPAL: labeled ‘Taksanggeb., b. Tukche, Takola [Pa327-327a, overleaf] / Zentral-Nepal, Sept.-Okt. 1971, lg. H. Franz / n. sp. / HOLOTYPE [red], ♂, Hingstoniella trigona sp. n., det. Yin & Li, 2014, MHNG’; in MHNG, without accession number.

Paratypes: NEPAL, 1 ♂, labeled ‘NEPAL, Kali Gandaki, vall., Nilgiri Himal. upp., Titigaon vill., 3000-3200 m NN, 21.V.2002, leg. J. Schmidt’. – 1 ♀, labeled ‘NEPAL, Annapurna Reg., Umg. Ghorepani, 2800 m, 28°24′15″N, 83°42′01″E, 22.IV.2000, leg. A. Weigel’. – 1 ♀, labeled ‘Zentral - Nepal, Annapurna - SW, 16.4.82, 4500 m, Baum / COLL. PANKOW [1 ex Myrmica pinned under specimen]’; in MHNG, without accession number. Each paratype bears a type label similar to that of holotype except ‘Paratype [yellow], ♂ [or ♀]’.

Description: Male (Fig. 3B). BL 3.36-3.44 mm. Body reddish brown; most part of dorsal surface densely hairy.

Head (Fig. 7A) distinctly transverse, HL 0.58-0.60 mm, HW 0.85-0.86 mm; vertex slightly convex, modification composed of distinct triangular bump, foveae located below level of posterior margins of eyes; each eye with about 40 small facets; antennal clubs formed by apical three enlarged antennomeres (Fig. 7B). Pronotum transversely octagonal, PL 0.70-0.73 mm, PW 1.04-1.06 mm, median longitudinal sulcus moderately developed. Elytra wider than long, EL 1.02-1.04 mm, EW 1.26-1.30 mm; shallow discal striae extending to half of elytral length. Metathoracic wings fully developed. Protibiae (Fig. 7C) slightly projected at mesal margins near apices; mesotrochanters (Fig. 7D) with small denticle at ventral margin; metatrochanters (Fig. 7E) with ventral margin protruding to form long projection. Abdomen wider than long, AL 1.04-1.09 mm, AW 1.17-1.18 mm. Aedeagus (Fig. 7F-I) asymmetric, length 0.50-0.51 mm.

Female. Similar to male in general appearance, protibiae, mesotrochanters, and metatrochanters lacking protuberance or projection. Each eye with about 35 facets. Tergite VIII (Fig. 7J) and sternite VIII (Fig. 7K) transverse. Genital complex (Fig. 7L) transverse, width 0.40 mm. Measurements: BL 3.48-3.56 mm, HL 0.58-0.59 mm, HW 0.87-0.88 mm, PL 0.76-0.77 mm, PW 1.14-1.15 mm, EL 1.03-1.07 mm, EW 1.33-1.35 mm, AL 1.07-1.17 mm, AW 1.20-1.26 mm.

Differential diagnosis: The new species can be separated from H. lata by the male possessing a different form of the vertexal modification, as well as the less projected apical portion of the protibiae, and the longer ventral projection of the metatrochanters.

Biology: One Myrmica ant is pinned under the female paratype from Annapurna, indicating that the new species probably represents a similar myrmecophily as H. lata.

Distribution: Nepal: Daulagiri (Fig. 12).

Type species: Besuchetaceus nepalensis sp. n.

Diagnosis: Head nearly triangular; frontal rostrum low; with distinct vertexal foveae; antennomeres XI elongate and conical. Pronotum transverse, with big lateral antebasal foveae; antebasal spines present; lateral margins spinose. Each elytron with three basal foveae, shallow and short discal striae present. Abdomen with lateral margins of tergite IV edged by marginal carinae; tergite IV longest.

Description: General body form elongate; Length 3.74-3.93 mm. Head nearly triangular (Fig. 8A); with low frontal rostrum, antennal tubercles slightly prominent; large vertexal foveae connected by broad U-shaped vertexal sulcus; antennae with 11 antennomeres, clubs loosely formed by apical three antennomeres, antennomeres XI elongate and conical; ocular-mandibular carinae distinct; eyes reniform (Fig. 8B); maxillary palpi with palpomeres III transverse and triangular, IV fusiform; with gular foveae merged into single opening (Fig. 8C). Pronotum (Fig. 8D) transverse; lateral antebasal foveae distinct, lateral margins spinose, lacking median antebasal fovea, with median and lateral longitudinal sulci, antebasal spines present; disc moderately convex; lacking basolateral foveae; lacking paranotal carinae; lateral procoxal foveae (Fig. 8E) present. Each elytron (Fig. 8F) with three distinct basal foveae, discal striae short and shallow, sutural striae complete; with subhumeral foveae, marginal stria present from fovea toward posterior margin; lateroapical notch small. Thorax (Fig. 9A) with small median and lateral mesoventral foveae; with lateral mesocoxal foveae; lacking prepectal foveae; lateral metaventral foveae small, metacoxae narrowly separated; posterior margin with narrow median notch. Abdomen (Fig. 9B-D) with tergites IV (first visible tergite), V, and VII bearing marginal carinae extending through whole tergal length; tergite IV longest, V-VII successively shorter; tergite IV with basolateral foveae at lateral ends of sulcus, lacking mediobasal foveae and discal carinae, V-VII each with one pair of basolateral foveae. Sternite IV (second visible ventrite) twice length of V at midlength, with one pair of mediobasal foveae and three pairs of basolateral foveae, basal sulcus between each mediobasal fovea and first pair of basolateral fovea, sternites V-VII lacking fovea. Legs slender, second and third tarsomeres subequal in length.

Male with vertex modified. Aedeagus with paramere fused to median lobe to form elongate ventral lobe; articulated dorsal lobe present; basal capsule with strongly constricted base.

Comparative notes: This new genus is placed as a member of the Hingstoniella group by the shared modified male vertex and the unique type of aedeagus. Besuchetaceus is most close to Sinotrisus by the similar general appearance, and each elytron possessing three basal foveae. The two genera can be separated by the spinose pronotal lateral margins, the shallow, complete basal sulcus, and the lack of discal carinae on tergite IV in Besuchetaceus, and the pronotum is generally more transverse. Sinotrisus has the pronotal lateral margins lacking spines or denticles, the pronotum is much less transverse, and tergite VI bears a deep basal sulcus interrupted by discal carinae or ridges. Besuchetaceus can be separated from Hingstoniella by the less robust habitus, the quite different shape of the pronotum, and the presence of three basal foveae on each elytron.

Etymology: The new genus is named after Claude Besuchet (Geneva, Switzerland), who firstly recognized this as a new genus placed near Hingstoniella, and added an identification label. Gender is masculine.

Holotype: ♂, NEPAL: labeled ‘Ost-Nepal, Rolwaling Himal / oberh. Simigaon, 2700-2800 m, 31.05.2000, leg. A. Kleeberg / gen. n. aff. Hingstoniella, Cl. Besuchet dét 2005 / HOLOTYPE [red], ♂, Besuchetaceus nepalensis sp. n., det. Yin & Li, 2014, MHNG’; in MHNG, without accession number.

Paratype: 1 ♀, labeled ‘Zentral-Nepal, Sept.-Okt. 1971, lg. H. Franz [Pa160, overleaf; according to Franz's dairy, the detailed collection data related to this number is: Thare-Pati, low Rhododendron-Juniperus forest, 8.10.1971, small sifting sample from litter, moss and humus (Schillhammer, per. comm.)] / Tare-Pati / PARATYPE [yellow], ♀, Besuchetaceus nepalensis sp. n., det. Yin & Li, 2014, MHNG’; in MHNG, without accession number.

Description: Male (Fig. 10A). BL 3.93 mm. Body reddish brown; most part of dorsal surface densely hairy.

Head (Fig. 11A) transverse, HL 0.69 mm, HW 0.79 mm; vertex convex at middle, modification composed of triangular bump covered with dense setae, foveae below level of posterior margins of eyes; each eye with about 60 small facets; antennal clubs formed by apical three enlarged antennomeres (Fig. 11B). Pronotum transverse, PL 0.76 mm, PW 0.93 mm, median longitudinal sulcus deep, lateral longitudinal sulci less developed. Elytra wider than long, EL 1.22 mm, EW 1.42 mm; shallow discal striae extending to basal 1/4 of elytral length. Metathoracic wings fully developed. Protibiae simple; mesotrochanters (Fig. 11C) with small, sharp spine at ventral margin, mesotibiae (Fig. 11D) with small apical spine; metatrochanters (Fig. 11E) with ventral margin protruding to form broad projection. Abdomen wider than long, AL 1.26 mm, AW 1.28 mm. Aedeagus (Fig. 11F-I) asymmetric, length 0.50 mm.

Female (Fig. 10B). Similar to male in general appearance, mesotrochanters, mesotibiae, and metatrochanters lacking protuberance or projection. Each eye with about 45 facets. Tergite VIII (Fig. 11J) and sternite VIII (Fig. 11K) transverse. Genital complex (Fig. 11L) transverse, width 0.45 mm. Measurements: BL 3.74 mm, HL 0.63 mm, HW 0.74 mm, PL 0.65 mm, PW 0.84 mm, EL 1.11 mm, EW 1.44 mm, AL 1.35 mm, AW 1.31 mm.

Differential diagnosis: Same as the genus, when combined with the form of the male modified vertex and leg characters, Besuchetaceus nepalensis can be readily separated from all other batrisine species.

Biology: The female paratype was sifted from a litter, moss and humus sample in a low Rhododendron-Juniperus forest on 10th October.

Distribution: Nepal: Bagmati, Janakpur (Fig. 12).

Etymology: The specific epithet refers to Nepal, the country where the type locality of the new species lies.