Clidicus yingjiangus, Cheng & Yin, 2019

Cheng, Zhi-Fei & Yin, Zi-Wei, 2019, Two new species of Clidicus Laporte, 1832 (Coleoptera: Staphylinidae: Scydmaeninae) from Yunnan, China, Zootaxa 4623 (2), pp. 321-330 : 326-329

Clidicus yingjiangus sp. nov.

( Figs 5–7 )

Type material (1 ex.). Holotype: CHINA: ♂, ‘ China: Yunnan, Yingjiang County (Ḇữƃ), Nabang Town (Ḅẉ Oi), 24°42′14.61″N, 97°35′17.56″E, in decomposing log, 669 m, 21.vi.2017, Bi Wen-Xuan leg. / HOLOTYPE (red) ♂, C. yingjiangus sp. nov., det. Cheng & Yin, 2019, SNUC’ (in SNUC) .

Diagnosis. Body size less than 5.0 mm. Anterior margin of frons nearly flat. Anterior margin of labrum with deep, triangular emargination at middle. Maxillary palpomeres 2–3 relatively long in relation to palpomere 4. Antennomeres 2–11 each distinctly elongate. Aedeagus markedly elongate, broadest at apical 1/4; parameres symmetric.

Description. Male, BL 4.67 mm, body ( Fig. 5A ) slender, with flattened head and strongly convex pronotum and elytra, covered with fine and dense setae, reddish-brown, tarsi slightly paler.

Head ( Fig. 5B ) subrectangular and transverse, broadest near middle, HL 0.89 mm, HW 1.11 mm; tempora 2.52× as long as eyes in dorsal view, evenly rounded; vertex with broad, subtriangular posteromedian impression; frons near each antennal insertion slightly impressed, both frons and vertex with narrow and deep longitudinal groove along midline; clypeus transverse and convex, demarcated from frons by deep and distinct fronto-clypeal groove; supraanternnal tubercles small but distinctly elevated. Eyes small, nearly round, not projecting laterally from the head silhouette, with fine facets. Punctures on vertex and frons small and indistinct; setae on head moderately long, sparse and suberect. Antennae ( Fig. 5C ) slender, all antennomeres distinctly elongate, relative lengths of the antennomeres I–XI: 3.44: 1.0:1.16: 1.28: 1.16: 1.16: 1.33: 1.09: 1.09: 1.05: 1.27; AnL 3.59 mm.

Labrum ( Fig. 5D ) subrectangular in dorsal view, with large, deep triangular emargination at middle of anterior margin; apical margin with six pairs of long and erect setae. Mandible ( Fig. 5E ) subtriangular, with broad and curved distal tooth; teeth slender; prostheca with short and dense setae from base to nearly middle of mandible. Maxilla ( Fig. 5F ) with triangular stipes and subtriangular palpifer with long setae on external margin, elongate galea and broad lacinia with short and dense setae. Maxillary palpus with dense short setae and additionally several long thick setae; palpomere 1 minute and elongate; palpomere 2 long and slender, broadened distally and slightly curved; palpomere 3 long and broadened, broadest near apex; palpomere 4 short, nearly subconical. Labium ( Fig. 5G ) elongate, with rectangular mentum nearly 2.5× as wide as long; prementum moderately large, with anterior surface flattened and divided by longitudinal groove, with several moderately long setae; labial palpus with several long setae, palpomere 1 short and broad, slightly longer than wide, with one long seta on antero-mesal margin; palpomere 2 strongly elongate, narrowed at base and broadening apically, with truncate apex, palpomere 3 subconical with pointed apex, much shorter and narrower than palpomere 2; lateral lobes of hypopharynx long, with dense microtrichia.

Pronotum in dorsal view inversely subtrapezoidal, broadest near anterior 1/4, PL 1.22 mm, PWb 0.83 mm, PWm 1.11 mm; disc convex, sharply demarcated from narrow posterior ‘collar’ by narrow transverse groove with small, slightly unevenly distributed pits. Punctures and setae on disc similar to those on head.

Comparative notes. The new species is most similar to C. chinensis Zhou & Li from Hainan, southern China, in a slender habitus and maxillary palpi, a symmetric aedeagus, a form of the sperm pump, a flat anterior margin of the frons, and a deep median emargination at the anterior margin of the clypeus. These two species can be readily separated by differences in the parameral apices, the relatively longer and slenderer flagellum of the aedeagus, as well as the relatively longer distance between the basal and the distal funnels of the sperm pump of the new species.

Comments. The single adult was found within a decomposing log, of which the habitat is similar to that of C. chinensis .

Distribution. Southern China: Yunnan ( Fig. 7 ).

Etymology. The new species is named after its type locality, i. e., Yingjiang County.

Figures

FIGURE 5. Diagnostic features of Clidicus yingjiangus male. A. Habitus. B. Head dorsum. C. Right antenna. D. Labrum. E. Right mandible. F. Left maxilla. G. Labium. Scale bars: 2 mm in A; 1 mm in C; 0.5 mm in B; 0.2 mm in D–G.

FIGURE 7. Distribution of extant species of Clidicus.