Odontalgus dongbaiensis Yin and Zhao

Yin, Zi-Wei, Newton, Alfred F. & Zhao, Tie-Xiong, 2016, Odontalgus dongbaiensis sp. n. from eastern China, and a world catalog of Odontalgini (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 4117 (4), pp. 567-579 : 568-572

Odontalgus dongbaiensis Yin and Zhao , new species

Type material. Holotype: Ƌ, CHINA: ‘ China: Zhejiang, Zhuji City, Dongbai Shan, 29°30′21.33″N, 120°26′55.59″E, sifted beneath a pile of straw, alt. ca. 400 m, 06.x.2014, T.-X. Zhao leg. / HOLOTYPE (red) Ƌ, Odontalgus dongbaiensis sp. n., det. Yin & Zhao, 2016’ ( SNUC). Paratype: 1 ♀, CHINA: ‘same label data as the holotype, except for ‘ 17.iv.2016 / PARATYPE (yellow) ♀ ’ ( SNUC)

Diagnosis. Body length 1.51–1.52 mm; antennomeres relatively slender, antennal clubs formed by three apical antennomeres in male, clubs shorter than remaining antennomeres combined; elytra with two discal ridges; protrochanters roundly expanded at ventral margins; aedeagal median lobe slightly asymmetric, lacking sclerotized endophallus.

Description. Male ( Fig. 1 A). Length 1.51 mm; reddish brown, mouthparts and tarsi lighter in color; body surface largely covered with squamous setae. Head ( Fig. 2 A–C) slightly transverse, HL 0.32 mm, HW 0.36 mm, strongly constricted at apical third; distinct antennal tubercles forming prominent frontal rostrum; vertex flat, vertexal foveae ( Figs 2 A, 3B; vf) small, close, situated at dorsal level of midline of eyes, also close to small frontal fovea ( Figs 2 A, 3B; ff); postocular margins short, densely setose posterolaterally; postantennal notches lacking, with large setose lateral postantennal pits ( Fig. 2 B; lpp); eyes large, each compose of about 30 facets; with triangular ocular canthi; maxillary palpi ( Fig. 2 B) with palpomeres I small, II lengthily pedunculate at basal halves, apical halves expanded, III short, roundly triangular, IV basally pedunculate, broadly rounded at apices, with sensory areas oblique dorsal at apices; antennae ( Fig. 3 A) 11-segmented, AnL 1.07 mm, AnCL 0.46 mm, AnCL/ AnL = 0.43; antennomeres I large and broad, about twice as long as II, III–VI each elongate, successively shorter, VII quadrate, as long as wide, VIII small, distinctly transverse, antennal clubs formed by antennomeres IX–XI, IX and X subequal in length, X slightly wider than IX, XI large, about 1.5 times as long as X, nearly oval, length of clubs shorter than combined length of remaining antennomeres; gula slightly concave, gular foveae ( Fig. 2 C; gf) in shared transverse opening, lacking median carina.

Pronotum ( Figs 2 D–F, 3B) transverse, broadest at basal fourth, narrowing apically, PL 0.30 mm, PW 0.36 mm; disc roundly convex, small median antebasal fovea ( Fig. 2 D; maf) and two pairs of lateral antebasal foveae ( Fig. 2 D–E; laf) connected by broad transverse antebasal sulcus; with one pair of mediobasal and two pairs of basolateral foveae ( Fig. 2 D; mbf, iblf, oblf); anterior portion of disc with one pair of anteromedian foveae ( Figs 2 D; amdf) and three pairs of anterolateral foveae ( Figs 2 D–E; aldf), inner pair of anterolateral foveae connected by Vshaped discal sulcus. Prosternite with small, deep, and widely separated lateral procoxal foveae ( Fig. 2 F; lpcf).

Elytra ( Figs 2 G, 3C) wider than long, widest at basal third, EL 0.46 mm, EW 0.67 mm; posterior margin with band of long, thick setae; each elytron with two large setose basal foveae ( Figs 2 G, 3C; bef); with indistinct subbasal fovea; sutural striae ( Fig. 2 G; ss) complete; with four complete discal striae ( Fig. 2 G; 1–4) forming two broad ridges. Metathoracic wings fully developed.

Mesoventrite ( Fig. 2 H) with median foveae ( Fig. 2 H; mmsf) widely separated, large lateral foveae ( Fig. 2 H; lmsf) forked, anterior pair of forks larger than posterior pair; with lateral mesocoxal foveae ( Fig. 2 H; lmcf). Metaventrite ( Fig. 2 H) with median foveae ( Fig. 2 H; mmtf) in transverse oval opening, forked anterolaterally; with pair of posteromedian foveae ( Fig. 2 H; pmmtf) meeting internally at middle; posterior margin nearly straight, lacking notch at middle, metacoxae widely separated.

Legs with femora covered with squamous setae; protrochanters ( Fig. 3 D) roundly projecting at ventral margins; third tarsomeres longer than second tarsomeres; with two claws subequal in length.

Abdomen ( Fig. 3 C) transverse, AL 0.43 mm, AW 0.61 mm. Tergites IV–VII each with complete paratergites; tergite IV (first visible tergite) largest, with broad, deep basal sulcus covered by dense setae, with two basolateral foveae; tergites V–VII subequal in length, each with basal impression and two basolateral foveae. Sternite IV (second visible sternite) with broad basal sulcus, lateral foveae forming large sockets; sternites V–VII each with basal impression and two basolateral foveae.

Aedeagus ( Fig. 3 E–G) well-sclerotized, length 0.19 mm; broad median lobe curved, apex roundly narrowed and leaned slightly leftwards; parameres elongate, broad at basal third and becoming slender apically, each paramere with two long apical setae; lacking endophallus.

Female ( Fig. 1 B). General habitus similar to male, with shorter antennae, less distinct antennal clubs, fewer eye facets, and a broader abdomen. Each eye composed of about 20 facets. Protrochanters roundly projecting ventrally as in male. Measurements: BL 1.52 mm, HL 0.32 mm, HW 0.37 mm, PL 0.31 mm, PW 0.38 mm, EL 0.46 mm, EW 0.66 mm, AL 0.43 mm, AW 0.67 mm, AnL 0.93 mm, AnCL 0.33 mm, AnCL/ AnL = 0.35.

Comparative notes. Six Odontalgus species have been known to occur in Asia, and two of them are from nearby areas of the new species: O. coreanus Löbl from North Korea and O. masaoi Arai & Nomura from Japan. Odontalgus dongbaiensis shares the similar additional foveae on the pronotal disc with O. masaoi , and a more or less similar aedeagus with O. coreanus . The new species can be readily separated from O. masaoi by the relatively much longer antennal clubs, and the aedeagus lacking an sclerotized endophallus which is greatly expanded leftwards in O. masaoi . It can be separated from O. coreanus by the thinner and relatively shorter antennal clubs, and elongate antennomeres II–VI; in O. coreanus , the antennal clubs are as long as the rest antennomeres combined, the antennomeres II and III are only slightly elongate and much broader than those in O. dongbaiensis , and the antennomeres IV–VI are distinctly transverse. Odontalgus dongbaiensis also somewhat resembles O. tuberculatus Raffray from western and eastern Africa and Yemen, the type species of the genus, in general habitus. These two species can be separated by the relatively shorter frontal rostrum, more transverse antennomeres VII, slightly longer antennal clubs, and much less distinct elytral carinae in the new species.

Distribution. Eastern China: Zhejiang.

Etymology. The specific epithet is taken after the type locality of the new species, i.e., Dongbai Mountain.

Figures

FIGURE 1. Dorsal habitus of Odontalgus dongbaiensis. A. male. B. Female. Scale lines: 0.5 mm.

FIGURE 2. Diagnostic features of Odontalgus dongbaiensis, male. A. Head, in dorsal view. B. Same, in lateral view, with maxillary palpomeres numbered. C. same, in ventral view. D. Pronotum. E. Prothorax, in lateral view. F. Prosternite. G. Left elytron. H. Meso- and metaventrite. Abbreviations: 1 – 4 indicate four discal striae, aldf—anterolateral discal foveae, amdfanteromedian discal foveae, bef—basal elytral foveae, ff—frontal fovea, gf—gular foveae, iblf—inner basolateral foveae, laflateral antebasal foveae, lmcf—lateral mesocoxal foveae, lmsf—lateral mesoventral foveae, lpcf—lateral procoxal foveae, lpp—lateral postantennal pits, maf—median antebasal fovea, mbf—mediobasal foveae, mmsf—median mesoventral foveae, mmtf—median metaventral foveae, oblf—outer basolateral foveae, pmmtf—posteromedian metaventral foveae, ss—sutural striae, vf—vertexal foveae. Scale lines: 0.2 mm.

FIGURE 3. Diagnostic features of Odontalgus dongbaiensis, male. A. Right antenna. B. Head dorsum, pronotum, and elytral base. C. Elytra and abdomen, in dorsal view. D. Protrochanter. E. Aedeagus, in dorsal view. F. Same, in lateral view. G. Same, in ventral view. Scale lines: A – C = 0.2 mm, D – G = 0.1 mm.