Sinotrisus nomurai Yin, Li & Zhao, 2010 (by original monotypy).

Head trapezoidal; frontal rostrum low, antennal tubercles moderately raised. Pronotum with median and lateral longitudinal sulci; small antebasal spines present, lacking lateral spines; median longitudinal sulcus broadened posteriorly to form longitudinal impression, usually lacking median antebasal fovea in impression. Elytra with three basal fovea, discal striae shallow, extending to half elytral length. Tergite IV longest, with thick triangular ridge formed by inner and outer marginal carinae.

Length 3.0–3.3. Reddish brown. Head trapezoidal; with frontal rostrum low, antennal tubercles moderately prominent; with nude, deep vertexal foveae; occipital margins usually carinate; postocular margins narrowing toward head base; with eleven antennomeres, clubs weakly to distinctly indicated by apical three antennomeres, ocular-mandibular carinae present; eyes roundly prominent; maxillary palpomeres III triangular, IV narrowed to base in basal half; gular carina present; foveae close in large pit.

Pronotum with distinct lateral longitudinal sulci, median longitudinal sulcus ending posteriorly as broader longitudinal antebasal impression, then followed by short median carina; lateral antebasal foveae distinct; antebasal spines minute or absent, small spines variably present along discal ridges; lateral margins lacking spines; with both inner and outer pair of basolateral foveae present; paranotal carinae at least extending anteriorly to half prosternal length; lateral procoxal foveae present.

Each elytron with three distinct basal foveae, shallow discal stria extending to half elytral length; with complete sutural and marginal striae. Thorax with lateral mesoventral foveae forked, median mesoventral foveae with openings touching, into shared transverse cavity; with large mesocoxal foveae; lateral metaventral foveae present; metaventrite with narrow posteromedian notch. Legs with second and third tarsomeres subsequent in length.

Tergite IV longer than subsequent one, with inner marginal carinae extending entire tergal length, together with outer marginal carinae forming thick triangular ridge; mediobasal sulcus deep between mediobasal foveae, sulcus bracketed by short, tuberculate discal carinae; lateral foveae at mesal and lateral margins of short, deep basolateral sulci; tergite V with thin marginal carinae, punctiform mediobasal and basolateral foveae present; VI with marginal carinae indistinct, mediobasal and inner pair of basolateral foveae as shallow trace; VII with one pair of basolateral foveae and minute lateral tubercles. Sternite IV about twice length of V at midline, with large mediobasal and two pairs of small basolateral foveae; sternites V–VII each with one pair of basolateral foveae. Foveae of abdominal segments V–VII often overlapped by previous segment.

Males with vertex, apices of mesotibiae and metatrochanters modified. Aedeagus with basal bulb greatly constricted basally; paramere fused to median lobe to form ventral lobe; articulated dorsal lobe offset to right side.

The genus ismorphologically similar to Batrisodes Reitter of the Batrisus genus-group, but does not fit any subgeneric concept sensu Park (1951). Sinotrisus is here placed as a member of Tribasodes group by the males having protuberant metatrochanters and the aedeagus with an articulated dorsal lobe (genus-groups sensu Nomura and Idris 2003). The large genus Batrisodes holds many Asian species described by Raffray (1894) and Jeannel (1958), but at least some of these need to be re-examined and likely will be moved to other genera of the Tribasodes group (Nomura and Idris 2003; Nomura 2007). Sinotrisus shares with Intestinarius Kurbatov, Dendrolasiophilus Nomura and Majappia Nomura of the Tribasodes group the lack of the pronotal lateral spines. Intestinarius was included in the genus Batrisodes, but was later treated as a separate genus (Kurbatov 2007). Members of this genus have the head bearing three longitudinal sulci and the pronotum bearing five similar sulci, and have the aedeagus with numerous hairs at the apex of the ventral lobe. Dendrolasiophilus and Majappia seem to form a smaller group by the derived loss of characters, specifically the absence of sulci on the pronotum and the frequent loss of basal elytral foveae. Dendrolasiophilus has one basal elytral fovea, and lacks elytral discal striae; Majappia has the vertexal foveae connected by a transverse sulcus, and completely lacks basal foveae on the elytra. Sinotrisus also shares with Hingstoniella the constriction of the basal portion of the aedeagus and the similar placement of the male sexual features, but the broadly triangular pronotum lacking antebasal tubercles and foveae, the presence of a large basal elytral fovea, and the lack of carinae on the margins of tergites V–VI in Hingstoniella readily separate it from Sinotrisus.

Holotype, male, labeled ‘Huangmaogeng Yakou / (2, 710 m). Tianxi Xiang / Meigu Xian // [Sichuan, China] / [same locality data in Chinese] / 5.x.1997, T. kishimoto // HOLOTYPE [red] / Sinotrisus kishimotoi sp. n. / Yin and Nomura / det. 2012, NSMT’. Paratypes, 3 females, same label data as holotype, all bearing the following label: ‘PARATYPE [yellow] / Sinotrisus kishimotoi sp. n. / Yin and Nomura / det. 2012, NSMT’.

Vertex strongly modified in male. Antennomeres VII slightly elongate. Pronotum with minute spines along discal ridges; basolateral foveae small. Mesotibiae with apical spur longer than first tarsomeres.

Male (Fig. 1A). Length 3.07. Head (Fig. 2A) slightly wider than long, HL 0.58, HW 0.65; vertex with deep cavity surrounding median triangular rostrum, anterior margin of cavity and posterior margin of rostrum edged by thickened ridge, cavity with tufts of setae at anterolateral margins, surface of rostrum densely setose, rostrum followed by short median carina; each eye composed of about 60 facets; lacking obvious occipital carinae; postocular margins evenly narrowed toward head base; antennomeres IV (Fig. 2B) subequal in length to VI, IX–XI enlarged to form distinct club. Pronotum about as long as wide, PL 0.64, PW 0.63; small median antebasal fovea in fusiform mediobasal impression; paranotal carinae extending half length of prosternum. Elytra slightly wider than long, EL 1.01, EW 1.16; slightly angulate at humeri. Mesotrochanters (Fig. 2C) with short, thick ventral spine; mesotibiae with apical spur (Fig. 2D) longer than first tarsomeres; metatrochanters (Fig. 2E) with broad, blunt elongate protuberance at ventral side. Abdomen wider than long, AL 0.84, AW 1.03; sternites IV with small triangular mediobasal ridge, V–VII with such ridge successively smaller. Aedeagus (Figs 2F–I) well-sclerotized, length 0.38.

Female (Fig. 1B). Similar to male in general, vertex and legs not modified. BL 3.05–3.12, HL 0.59–0.60, HW 0.67–0.68, PL 0.66–0.67, PW 0.64–0.66, EL 0.97–0.99, EW 1.16–1.18, AL 0.83–0.86, AW 1.07–1.10. Each eye composed of about 55 facets. Genital complex well-sclerotized (Figs 2J–K).

SouthwestChina: Sichuan.

Formica sp.

Named after the collector of the holotype, T. kishimoto.

Holotype, male, labeled ‘China: Zhejiang Prov. / W. Tianmushan Mt. / firebreak / 01.v.2009, 1, 400 m / Xiao-Bing SONG leg. // HOLOTYPE [red] / Sinotrisus nomurai sp. n. / Yin and Li / det. 2010, SNUC’. Paratype, male, same label data as holotype, with the following label: ‘PARATYPE [yellow] / Sinotrisus nomurai sp. n. / Yin and Li / det. 2012, SNUC’.

Vertex modified in the male. Antennomeres VII transverse. Pronotum lacking spines along discal ridges; basolateral foveae broad. Mesotibiae with one tiny and one long apical spur.

Male. Length 3.30. Head (Fig. 3A) wider than long, HL 0.57, HW 0.71; surface convex anterior and posterior to vertexal foveae, forming median angulate projection; with distinct occipital carinae; postocular margins evenly narrowed toward head base; antennomeres IV (Fig. 3B) smaller than VI, IX–X transverse, XI nearly oval, clubs indistinct. Pronotum about as long as wide, PL 0.66, PW 0.68; mediobasal impression longitudinally oval, lacking median antebasal fovea; paranotal carinae extending through length of prosternum. Elytra slightly wider than long, EL 1.06, EW 1.18; angulate at humeri. Mesotrochanters (Fig. 3C) with long ventral spine slightly curved toward base in apical half; mesotibiae with apical spur (Fig. 3D) longer than first tarsomeres; metatrochanters (Fig. 3E) with blunt triangular tubercle and large elongate protuberance at ventral side. Abdomen slightly wider than long, AL 0.96, AW 1.08; tergites and sternites V–VII with basolateral ridges successively shorter and thinner. Aedeagus (Figs 3F–I) well-sclerotized, length 0.42.

Female. Unknown.

East China: Zhejiang.

Lasius sp.

Holotype, male, labeled ‘Majiagou (3, 140 m) / Kangding Xian / [Sichuan, China] / [same locality data in Chinese] / 9.ix.1998 / Toshio Kishimoto leg. // HOLOTYPE [red] / Sinotrisus sinensis sp. n. / Yin and Nomura / det. 2012, NSMT’.

Vertex modified in male. Antennomeres VII elongate. Pronotum with indistinct spines along discal ridges; basolateral foveae punctiform. Mesotibiae with one tiny and another larger apical spur, larger spur shorter than first tarsomeres.

Male (Fig. 4A). Length 3.20. Head (Fig. 5A) wider than long, HL 0.61, HW 0.66; vertex with foveae in broad median ‘∞’-shaped cavity, cavity densely setose at anterior margin; lacking occipital carinae; postocular margins parallel for short distance beneath eyes, then evenly narrowed toward head base; antennomeres IV (Fig. 5B) slightly shorter than VI, clubs formed by apical three antennomeres, IX–X nearly quadrate, XI elongate, narrowed toward apex in apical half. Pronotum slightly longer than wide, PL 0.65, PW 0.62; median longitudinal sulcus slightly widened to form oval antebasal impression, lacking median antebasal fovea; paranotal carinae extending through length of prosternum. Elytra slightly wider than long, EL 1.02, EW 1.17; slightly angulate at humeri. Mesotrochanters (Fig. 5C) with thick, short ventral spine; mesotibiae with apical spur (Fig. 5D) shorter than first tarsomeres; metatrochanters (Fig. 5E) with large elongate ventral projection. Abdomen slightly wider than long, AL 0.92, AW 1.05; sternites IV–VI with triangular mediobasal and basolateral ridges successively shorter and thinner. Aedeagus (Figs 5F–I) well-sclerotized, length 0.41.

Female. Unknown.

Southwest China: Sichuan.

Formica sp.

Named after the country where the type locality lies.

Holotype, male, labeled ‘Mt. Phang Si Pang (moss: / 2, 000 m). Lai Chau Prov. / [N. VIETNAM] / 17.v.2003, S. Nomura leg. // HOLOTYPE [red] / Sinotrisus vietnamensis sp. n. / Yin and Nomura / det. 2012, NSMT’.

Vertex modified in male. Antennomeres VII greatly transverse. Pronotum lacking spines along discal ridges; basolateral foveae small. Mesotibiae with apical spur about as long as first tarsomeres.

Male (Fig. 4B). Length 3.00. Head (Fig. 6A) distinctly wider than long, HL 0.57, HW 0.71; frons convex medially, extending posteriorly to anterior margin of vertexal cavity; shallow transverse cavity with large foveae, area posterior to cavity strongly raised medially to form rostrum, densely covered with setae; with distinct occipital carinae; postocular margins evenly narrowed toward head base; antennomeres IV (Fig. 6B) about same length as VI, clubs formed by apical three antennomeres, IX strongly transverse, X slightly longer than IX, XI nearly oval, narrowed toward apex in apical half. Pronotum about as long as wide, PL 0.63, PW 0.65; median longitudinal sulcus slightly widened posteriorly to form shallow oval antebasal impression, lacking median antebasal fovea; paranotal carinae extending through length of prosternum. Elytra slightly wider than long, EL 0.92, EW 1.13; barely angulate at humeri. Mesotrochanters (Fig. 6C) with long basoventral spine; mesotibiae with apical spur (Fig. 5D) about same length of first tarsomeres; metatrochanters (Fig. 6E) broadly expanded ventrally, with small blunt tubercle at ventral margin. Abdomen slightly wider than long, AL 0.88, AW 1.10; segments lacking basal ridges. Aedeagus (Figs 6F–I) well-sclerotized, length 0.39.

Female. Unknown.

Vietnam: Lai Chau.

The individual was collected from a pile of moist moss.

Named after the country where the type locality lies.