Pseudophanias yaimensis Inoue, Nomura & Yin, 2020

Inoue, Shota, Nomura, Shuhei & Yin, Zi-Wei, 2020, Three new species of Pseudophanias Raffray from Japan and Taiwan Island, and synonymy of Chandleriella Hlavac with Pseudophanias (Coleoptera, Staphylinidae, Pselaphinae), ZooKeys 987, pp. 135-156 : 135

Pseudophanias yaimensis Inoue, Nomura & Yin sp. nov. Figs 1 , 2 , 3 , 4 [Japanese name: Yaima-tsumugata-arizukamushi]

Type material.

Holotype (NSMT): ♂, "Japan: [ Ryûkyû], Ishigaki- / jima, Takeda-rindô 23 X 2007, Teruaki Ban leg. // HOLOTYPE (red) /♂, Pseudophanias yaimensis sp. nov., / det. Inoue, Nomura & Yin, 2020" Paratypes: Japan: 1 ♀, [ Ryûkyû], Okinawa ken, Ishigaki-jima Is., Mt. Omoto-dake, 16 VIII 1991, K. Ogata leg. (NSMT); 1 ♂, Ishigaki-jima Is., Mt. Omoto-dake, (FIT), 14-20 V 2002, S. Hori leg. (NSMT); 1 ♂, 1 ♀, China: Taiwan, Taichung Co. (台中县), Guguan (谷关), 1238 m, 24.180691N, 120.944213E, 29 III 2015, local collector, nest of Nasutitermes parvonasutus (SNUC). Each paratype pinned with the following label: "PARATYPE (yellow) / ♂ (or ♀), Pseudophanias yaimensis sp. nov., / det. Inoue, Nomura & Yin, 2020".

Diagnosis.

Pseudophanias yaimensis is most similar to the Sumatran P. robustus Raffray, 1904, but can be distinguished by the distinctly smaller body size (3.00-3.20 mm in P. robustus ), the angulate antennomere 11 at anterolateral margins in the male, the finely punctate head and pronotum, and the shorter discal carinae on tergite IV.

Description.

Male (Figs 1A , 2A ). Body length 2.16-2.32 mm. Dorsal surface polished and weakly shining, with dense setae. Head (Fig. 3A ) about as long as wide, HL 0.46 mm, HW 0.42-0.44 mm, same size as pronotum, nearly hexagonal, with dense setae; frontal rostrum with short longitudinal sulcus including large fovea; antennal tubercles prominent, with dense punctures which gradually disappear towards vertex; vertex polished, finely punctate, with pair of foveae; frontal, vertexal foveae glabrous; eyes prominent; postocular margins three times longer than length of eyes. Maxillary palpi (Fig. 3B ) symmetrical; palpomere 1 minute; palpomere 2 elongate, narrowed in basal half; palpomere 3 small, widest at apices; palpomere 4 fusiform. Antennae (Fig. 2B ) elongate, 1.42 mm in length; antennal club formed by apical antennomere alone; antennomere 1 thick, elongate, 1.5 times longer than 2; 2 slightly longer than wide; 3-11 successively widened towards apices; 3-7 each slightly elongate; 8-10 quadrate; 11 enlarged, roundly broadened towards apices in inner margin, straightened towards apices in outer margin; each apical half of outer margin distinctly carinate, with angulate spine at anterolateral part. Pronotum (Fig. 3C ) slightly longer than wide, PL 0.48 mm, PW 0.46 mm; widest at anterior one-third, weakly constricted from widest point towards base, polished, with coarse punctures along posterior margin, with a median and pair of lateral antebasal foveae, with distinct conical spine just anterior of median fovea. Metaventrite (Figs 2D , 3D ) finely punctate, moderately convex, but area just above metaventral apex impressed; that impression nearly trapezoidal, half as long as metaventral length, occupying 1/4 metaventral width; anterior margin of that impression straight, distinct. Elytra (Fig. 3E ) nearly trapezoidal, widest near posterior 1/4 much wider than long, EL 0.60-0.62 mm, EW 0.85-0.94 mm; dorsal surface polished, with thin, long setae, finely punctate; each elytron with two basal foveae; discal stria shallow, extending from basal fovea placed middle to posterior half. Legs. All legs elongate and slender; femora each broadest near middle; tibiae each slightly broadened to apex, with dense yellow setae at apex; protibiae and mesotibiae nearly straight; metatibiae longest; tarsi each elongate, with tarsomeres 2 about as long as tarsomeres 3; mesotarsi (Fig. 3G ) modified, broadest; tarsomeres 3 each with projection of 2/3 length of entire tarsomere; tarsal claws (Fig. 3H ) each asymmetrical; posterior claws thin, short. Abdomen (Fig. 3F ) wider than long, widest at tergite IV, AL 0.62-0.76 mm, AW 0.85-0.90 mm; tergite IV longest, twice as long as tergite V, with pair of short longitudinal carinae about one-fifth as long as tergal length, with setose depression at base. Tergite and sternite VIII as in Fig. 4D, E . Aedeagus (Fig. 4A-C ) 0.39-0.40 mm in length, well-sclerotized, asymmetrical; parameres elongate, reaching near apex of median lobe; each paramere with three setae at apex; median lobe strongly widened towards apex in dorso-ventral view, constricted at median part in lateral view; ventral side of apical part asymmetrical, weakly sclerotized, nearly formed three pronged fork; medioapical part bended laterally; dorsal side of apical part asymmetrical, bifurcate from median part; endophallus indistinct.

Female (Fig. 1B ). BL 2.20-2.32 mm; HL 0.40-0.52 mm; HW 0.42-0.45 mm; PL 0.46-0.49 mm; PW 0.44-0.46 mm; EL 0.58-0.63 mm; EW 0.78-0.89 mm; AL 0.70-0.76 mm; AW 0.86-0.90 mm. Antennae (Fig. 2C ) with antennomeres 11 unmodified, each ovoid, without carina and angulate spine; eyes smaller than male; mesotarsi without projection.

Etymology.

Ishigaki Island, where the type locality of this species was discovered, is a part of the Yaeyama Islands. This specific epithet refers to Yaima which is a local dialect of the Yaeyama Islands.

Distribution.

Japan ( Ryûkyû: Ishigaki-jima Is.), China (Taiwan).

Biology.

Two paratypes from Taiwan were collected with the termite Nasutitermes parvonasutus Nawa, 1911. In Japan, one paratype was collected using a Flight Interception Trap (FIT).

Remarks.

This species is distributed in Yaeyama-shotô Islands, Japan and Taiwan, China. The two localities are close to each other and shared the same fauna for some insect groups. The two populations show slight difference in the morphology of the aedeagus. The lateral projections of the median lobe of the population of Taiwan are relatively longer and narrower than those of the population of Yaeyama. But the general appearance and especially the male sexual characters are otherwise almost identical. Therefore, we treat such a difference as interspecific variation.

The Taiwanese specimens were collected from a nest of the Nasutitermes parvonasutus termite. However, the Japanese specimens were collected from leaf litter samples or by FIT. Some pselaphine species are known to live under the bark and rotten wood with termites. Thus, more information is needed to recognize the possible termitophyly of the new species.

Figures

Figure 1. Dorsal habitus of Pseudophanias yaimensis A male B female. Scale bar: 1.0 mm.

Figure 2. Morphological details of Pseudophanias yaimensis A habitus in lateral view B male antenna C female antenna D male metaventrite. Scale bars: 1.0 mm (A); 0.5 mm (D); 0.2 mm (B, C).

Figure 3. SEM images of Pseudophanias yaimensis, male A head B maxillary palp C pronotum D metaventrite E elytra F abdomen G mesotarsus H mesotarsal claws. Scale bars: 0.2 mm (A, C-G); 0.1 mm (B); 0.05 mm (H).

Figure 4. Male genitalia of Pseudophanias yaimensis A ventral view B lateral view C dorsal view D tergite VIII E sternite VIII. Scale bars: 0.1 mm.