Nipponobythus flamma, Zhang & Yin, 2025

Zhang, Yong-Qin & Yin, Zi-Wei, 2025, The ant-like litter beetle fauna from the Wumenshan National Nature Reserve, China, with description of eight new species (Staphylinidae: Pselaphinae), European Journal of Taxonomy 1007, pp. 133-162 : 153-156

Nipponobythus flamma sp. nov.

Chinese common name: AE奇首ü甲 urn:lsid:zoobank.org:act:24B0200D-389D-4FDC-A5FC-7F39E7068EA8 Fig. 7

Diagnosis

Male

Body length approximately 1.6 mm. Head truncate at base, approximately as wide as pronotum, vertex lacking foveae, with relatively short mediobasal carina; apical part of vertex projected to form ‘shield-like’ structure, anterior margin of projection with tufts of long, flame-like setae, with relatively short mediobasal carina; frons with broad cavity at middle, anteriorly with complex tubercle at middle; antenna simple, antennomeres more or less transverse, with indistinct club. Pronotum lacking foveae, area posterior to antebasal sulcus roughened, with distinct impressions; posterior corners angularly tuberculate. Legs simple, unmodified. Tergite 1 (IV) with short, broadly separated discal carinae, each carina extending posteriorly to less than ⅓ of tergal length. Aedeagus moderately elongate, each paramere each with five macrosetae at apex and mesal margin, respectively, endophallus armature composed of two elongate sclerites at middle and spine-like structures at apical half.

Female

Body length approximately 1.7 mm. Vertex lacking modifications. Compound eyes much smaller.

Etymology

The species epithet is a Latin noun meaning ‘flame’ or ‘fire’, indicating the unique cephalic structure of this species. The name is a noun in apposition.

Type material

Holotype

CHINA • ♂; Yunnan, Zhaotong City, Wumengshan Conservation Area, Miaoshan , Xiaocaoba ; 27°29′33″ N, 104°10′19″ E; 1709–1800 m a.s.l.; 20 Jul. 2022; Wei leg.; Ǖ南昭ª市乌®山小ẽữ, 魏 ǡ豪*; SNUC.

Paratypes

CHINA • 1 ♂, 1 ♀; same data as for holotype; SNUC .

Description

Male

BODY ( Fig. 7A ). Length 1.56–1.65 mm; colour reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body covered with relatively dense pubescence.

HEAD ( Fig. 7B ). Roundly rectangular, broadly truncate at base, much wider than long, length 0.32– 0.34 mm, width 0.43 mm; apical portion of vertex raised to form broad ‘shield-like’ projection, anterior margin of projection with tufts of long, curved setae, flame-like, lacking foveae (dorsal tentorial pits) due to modification, vertex laterally roundly expanded and coarsely punctate on expansions, mediobasal carina relatively short, extending from head base anteriorly to projection, postocular carinae complete; tempora slightly longer than eyes; frons greatly and broadly excavated, anteriorly with complex tubercle at middle; clypeus smooth, short, sharply descending, with anterior margin carinate and moderately raised; ocular-mandibular carinae thin, complete. Venter with coarse surface; small gular foveae (posterior tentorial pits) narrowly separated, in shared impression, lacking median carina. Compound eyes weakly protruding from outline of head, each composed of approximately 40 ommatidia. Antenna relatively elongate, length 0.66–0.68 mm, unmodified, with indistinct club; antennomere 1 thick, subcylindrical, enlarged, 2 subquadrate, 3 much smaller than 2, 4–9 each submoniliform, 10 distinctly transverse, subconical, 11 largest, longer than 9 and 10 combined (17:10), conical.

PRONOTUM ( Fig. 7B ). Wider than long, length 0.34–0.35 mm, width 0.39–0.41 mm, widest anterior to middle, posterior corners angularly protruding; lateral margins rounded, convergent anteriorly and posteriorly; both anterior and posterior margins smoothly curved; disc weakly convex, finely punctate, lacking foveae, with distinct transverse antebasal sulcus demarcating disc from basal collar, basal collar roughened and with two pairs of oval impressions. Prosternum with basisternal (precoxal)

portion approximately as long as procoxal rests, with small, narrowly separated lateral procoxal foveae; hypomeral grooves complete; hypomeral ridges adjacent to margins of coxal cavities.

ELYTRA. Much wider than long, length 0.46–0.53 mm, width 0.71–0.72 mm; each elytron with two moderately large, asetose basal foveae; disc lacking striae; humeral denticles absent, humeri weakly prominent, lacking subhumeral foveae or marginal stria; posterolateral margin with narrow cleft. Metathoracic wings fully developed.

MESOVENTRITE. Short, laterally fused with metaventrite; median mesoventral foveae moderately separated, originating from shared oval impression, lateral mesoventral foveae forked internally, prepectus massive, collar-shaped; with short, apically blunt mesoventral process; with complete marginal striae. Metaventrite moderately raised admesally, with small, asetose lateral mesocoxal and two tiny lateral metaventral foveae, metaventral intercoxal process with broad emargination at middle.

LEGS. Moderately elongate, lacking modification; tibiae each with row of dense setae on mesal margin at apex.

ABDOMEN. Widest at lateral margins of tergite 1 (IV), length 0.48–0.51 mm, width 0.66–0.68 mm; paratergites well-developed. Tergite 1 (IV) at middle longer than 2 (V) to 4 (VII) combined and approximately 3.8× as long as 2, basal sulcus broad and moderately deep, with pair of small mediobasal foveae, discal carinae ( Fig. 7C ) moderately broadly separated, short, extending posteriorly to less than ⅓ of tergal length; tergites 2 and 3 subequal in midlength, 4 slightly longer, 2–4 each with thin basal sulcus and lacking fovea; tergite 5 (VIII) greatly transverse, posterior margin evenly rounded. Sternite 2 (IV) at middle longer than 3–5 (V–VII) combined, with markedly short mediobasal carina, with one pair of basolateral foveae and one pair of basolateral sockets; sternites 3–5 at middle gradually shorter, lacking foveae, sternite 6 (VIII) ( Fig. 7D ) transverse, with pair of lateral and one median projection, median projection much shorter than lateral ones, sternite 7 (IX) ( Fig. 7E ) composed of pair of weakly sclerotized, elongate sclerites.

AEDEAGUS ( Fig. 7F–G ) 0.38 mm long, moderately elongate, dorso-ventrally symmetric; median lobe moderately sclerotized; endophallus armature composed of complex of sclerites at middle, and with spine-like structures at apical half; each paramere each with five macrosetae at apex and along mesal margin.

Female

Similar to male in external appearance. Vertex lacking modifications. Antenna approximately as long as that of male. Each compound eye composed of 10 ommatidia. Base of elytra slightly constricted. Metathoracic wings absent. Measurements (as for male): body length 1.74 mm; length/width of head 0.35/ 0.44 mm, pronotum 0.34/ 0.40 mm, elytra 0.48/ 0.71 mm; abdomen 0.65/ 0.70 mm; length of antenna 0.64 mm.

Remarks

The diversity of Nipponobythus in China remains largely underexplored, with numerous species awaiting formal description (ZWY’s personal observation). Many of these species, including the new species described here, exhibit distinct cephalic modifications. One recently described species, N. alienoceps Yin, 2020 , from a cave in Guizhou, possesses a significantly modified head in males (Yin 2020). However, all species known to the authors can be readily identified by their unique male sexual characters, and through careful examination of the aedeagal structure, which is species-characteristic.

Distribution

Southwest China: Yunnan.

Figures

Fig. 7. Nipponobythus flamma sp. nov., holotype, ♂ (SNUC). A. Dorsal habitus. B. Head and pronotum. C. Tergite 1 (IV). D. Sternite 6 (VIII). E. Sternite 7 (IX). F–G. Aedeagus, ventral views. Scale bars: A = 0.5 mm; B = 0.3 mm; C = 0.2 mm; D–G = 0.1 mm.