Bolitobius lilizheni Yin and Hu, 2022

Yin (殷子为), Zi-Wei & Hu (胡佳耀), Jia-Yao, 2022, A New Tibetan Species of Bolitobius Leach (Coleoptera: Staphylinidae: Mycetoporinae), The Coleopterists Bulletin 76 (3), pp. 381-385 : 382-384

Bolitobius lilizheni Yin and Hu , new species zoobank.org/ urn:lsid:zoobank.org:act:781A9130-A10D-4B56-A440-E867E5CE10AD ( Figs. 1 , 2 ) Chinese common name: ḞKffiãDOiffl

Type Material. HOLOTYPE: CHINA: ♂, “China: Xizang, Nyingchi City, Tongmai Town , pass nr. 102 Tunnel , 30°04′15′′ N, 95°08′07′′ E, 2150–2400 m, 12.vii.2021, Peng, Yin & Zhang, ĦflDz9 102 Ŀfi ” ( SNUC).

Diagnosis. Male. Total body length approximately 7.0 mm, forebody length 3.8 mm; head, pronotum, elytral disc, and abdomen except for posterior margin of tergite VII uniformly black; head, pronotum, and elytra lacking microsculpture, abdomen with only segment IX with observable transverse microsculpture; antennomere 11 approximately 1.67 times as long as wide; elytron with large, light yellowish macula posterior to humeral angle; sternite VII with eight short bristles at middle of posterior margin, sternite VIII angularly protruding at middle of posterior margin, fields of bristles fusing at base; aedeagus with median lobe bulged at apex, parameres surpassing median lobe by approximately half their length, endophallus with pair of elongate sclerites at apex and with group of irregular sclerites at base. Female. Unknown.

Description. Male. Coloration. Head and pronotum black; antennomeres 1 and 2 yellowish-brown, 3–10 black, 11 yellowish-white; elytra including scutellar shield black, with large pale-yellowish humeral maculae; legs black, with dark reddish-brown tarsi; abdomen black, posterior margin of tergite VII and apex of segment X pale in color.

Measurements. Total body length (from anterior margin of clypeus to apex of abdomen) 7.1 mm; forebody length (from anterior margin of clypeus to apex of elytra) 3.8 mm; midlength of head (from anterior margin of clypeus to anterior margin of pronotum) 0.92 mm, maximum width of head (across eyes) 0.87 mm; midlength of pronotum 1.23 mm, maximum width of pronotum 1.60 mm; length of scutellar shield 0.13 mm; length of elytra along suture 1.46 mm, along humerus (from humeral angle to posterior margin) 1.86 mm, maximum width of elytra 1.86 mm; length of abdomen 3.32 mm, maximum width of abdomen (at base of tergite III) 1.55 mm; length of antenna 2.22 mm, length of antennomere 11 (excluding basal stalk) 0.35 mm, maximum width 0.21 mm, relative lengths of antennomeres 1–11: 30:17:20:17:17:18:17:17: 17:18:34; length of aedeagus including parameres 1.63 mm, length of median lobe 1.11 mm.

Microsculpture.Head, pronotum, and elytra lacking microsculpture, abdomen with only segment IX bearing distinct transversely meshed microsculpture.

Habitus elongate, fusiform. Head slightly longer than wide; eyes convex, roundly protruding from outline of head; temples subparallel posterior to eyes and forming “neck” region, slightly shorter than eyes (ratio 0.7:1.0); anterolateral margin of clypeus with three macrosetae, posteromesal margin of antennal fossa with one macroseta, and area mesal to posterior margin of eye with one macroseta. Antennae elongate, covered by short pubescence and long setae, surpassing posterior margin of pronotum when extending posteriorly; antennomeres 1–3 distinctly elongate, 4–10 much broader, roundly quadrate, 11 approximately as long as 9 and 10 combined, elongate-suboval, distinctly longer than wide, ratio 1.68:1, truncate at base and rounded at apex.

Pronotum moderately transverse, ratio of maximum width to midlength 1.3:1, slightly more than 1.8 times as broad as head, broadest posterior to middle, strongly narrowing from broadest point anteriorly, less so posteriorly; anterolateral corner roundly angulate, anterior margin roundly convex at middle, posterior corner broadly and obtusely rounded, posterior margin slightly arched; anterior, lateral, and posterior margin each with four macrosetae.

Elytra along suture slightly shorter than combined width (ratio 0.78:1) and along humerus as long as wide (1:1), slightly broadening posteriorly, broadest at approximately posterior 1/4; each elytron with large, sub-rounded macula posterior to humeral angle; sutural, discal, lateral, and posterior row of bristles distinct, each composed of 8 (sutural), 8 (discal 1), 6 (discal 2), 7 (discal 3), 6 (discal 4), 9 (discal 5), 8 (lateral), and 5 (posterior) bristles, epipleuron with approximately 20 shorter, smaller bristles.

Legs slender; protarsus slightly dilated, protarsomeres 1 to 5 successively narrower; meso- and metatibiae with long spines, tarsomeres elongate, tarsomeres 1 to 4 successively shorter, 5 much longer than 4.

Abdomen elongate, tapering posteriorly. Tergites III to VI each with row of long bristles along posterior margin, IV to VI also with short setae at bases, tergite III at middle with broad area lacking punctures, IV to VI with similar but successively smaller asetose area at middle, tergite VII trapezoidal, with short setae at base and long bristles on disc, VIII tapering from base towards apex, with exceptionally long bristles along lateral and posterior margins, tergite IX lacking bristles, X with long bristles covering whole surface; sternite VII with posterior margin medially broadly emarginate, with 8 short bristles at middle. Sternite VIII with posterior margin angularly protruding at middle, preceded by basally-fused fields with dense bristles; sternite X with basal half slightly wider than apical half, posterior margin with 9–10 long bristles and many shorter setae.

Aedeagus with short median lobe with bulged apex; endophallus with complex of irregular sclerites at base and pair of elongate sclerites at apex; parameres elongate, surpassing median lobe by half of their lengths, each paramere broadened at level of base of apical bulge of median lobe, with dense row of 8–9 short setae, roundly broadened at apex, with two preapical setae and two additional setae at approximately apical 1/5 along mesal margin.

Female. Unknown.

Comparative Notes. Following Schülke (1993), this species is placed as a member of the B. setiger group. It resembles B. emeishanus from Sichuan by the similar form of the aedeagus which has a bulged apex of the median lobe. Bolitobius lilizheni differs from B. emeishanus by the black elytra lacking a yellowish posterior margin, the elytral maculae not reaching the elytral bases, the fields of bristles of male sternite VIII fused at the base (bristles arranged in two clearly separated fields in B. emeishanus and in all other species of the B. setiger group), and the different structure of the endophallus of the aedeagus.

Distribution and Habitat. SW China: Tibet (Xizang). The single male was collected by sifting leaf litter in a mixed forest at an altitude of 2,150 – 2,400 m. The new find fills a large geographical gap between Nepal and Sichuan, China, where no Bolitobius had been previously reported.Additional Tibetan species of Bolitobius are expected to be determined by future collecting efforts in this poorly explored area harboring an evidently high diversity of rove beetles (e.g., Yin 2022).

Etymology. This species is named after our former supervisor Li-Zhen Li, who has made a significant contribution to the Asian Mycetoporinae and Tachyporinae fauna.

Remarks. One female collected at the same day and location with B. lilizheni has yellow posterior margins of the elytra, and three other females collected from Zhêntang Town (27°54–55′N, 87°29– 32′E) have a dark brown antennomere 11. Each of these populations may represent different species.

Figures

Fig. 1. Bolitobius lilizheni, new species, male. A) Dorsal habitus, B) Right elytron, showing form of macula and position of bristles, dorsal view, C) Sternite VII, ventral view, D) Sternite VIII, ventral view, E) Fields of bristles of sternite VIII, enlarged, ventral view, F) Sternite X, ventral view. Scale bars: 2.0 mm in A; 0.5 mm in B–D, F; 0.2 mm in E.

Fig. 2. Bolitobius lilizheni, new species, male. A–C) Aedeagus, dorsal (A), lateral (B) and ventral (C), with endophallus in dorsal view and parameres in lateral and ventral view outlined, D) Apex of left paramere (dorsal view), enlarged, showing position of setae. Scale bars: 0.5 mm in A–C; 0.1 mm in D.