Meligethes macrofemoratus, Liu, Meike, Yang, Xingke, Huang, Min, Jelínek, Josef & Audisio, Paolo, 2016

Liu, Meike, Yang, Xingke, Huang, Min, Jelínek, Josef & Audisio, Paolo, 2016, Four new species of Meligethes Stephens from China and additional data on other species of the genus (Coleoptera: Nitidulidae: Meligethinae), Zootaxa 4121 (2), pp. 101-116 : 102-105

Meligethes (s.str.) macrofemoratus sp. nov.

( Figs. 1–2 , 21, 23 –27)

Diagnosis. Meligethes macrofemoratus sp. nov. is a member of the M. binotatus-auripilis group (as delimited by Audisio et al. 2015), where it appears to be related to M. argentithorax Audisio, Sabatelli & Jelínek, 2015 , to M. auripilis Reitter, 1889 , and M. clinei Audisio, Sabatelli & Jelínek, 2015 , these four species share a uniformly blackish to dark-brown body coloration, combined with piceous-brown to orange legs and antennae, with dark antennal club and only somewhat paler (dark brown to brown) or blackish pronotal sides. The new species can be easily differentiated by the peculiarly shaped male genitalia ( Figs. 1–2 ), the tegmen being large, wide, and exhibiting a relatively deep, pear-shaped distal excision [the aedeagus being also large, widest at its basal fifth, with pre-distally abruptly narrowed and distally widened spatulate apex, a condition superficially recalling that of the widespread Palearctic M. (s.str.) flavimanus Stephens, 1830, which otherwise belongs to the M. (s.str.) atratus group]. Other significant differences occur in its exceptionally developed male metafemora, which when extended, protrude outwards beyond the elytral lateral edge more than in all other known species of the genus. The ratio between the protrusion of distal apex of male metafemora beyond elytral lateral edge is more than 0.33× the head width (HWEA: Figs. 26–27). This character state is combined with peculiarly curved and sinuate male meso- and metatibiae ( Figs. 23 , 26–27), which are slightly modified even in females ( Fig. 24 ). Female genitalia of M. argentithorax , auripilis and macrofemoratus spp. nov. are also different, with distinctive combined apices of the ovipositor ( Fig. 21 ; Figs. 15 l, m in Audisio et al. 2015), although being rather similar in size and general shape (those of M. clinei are unknown). The vaguely similar general shape of the median lobe of the aedeagus also suggests a possible relationship with M. transmissus Kirejtshuk, 1988 (from Sichuan and Yunnan), the latter being otherwise quite different in most other characters, including coloration, tegmen, and female genitalia.

Description (male holotype). Size: Length 3.8 mm, width 1.9 mm.

Body color and pubescence: External habitus and coloration as figured (Figs. 26–27); dorsal and ventral body surface uniformly blackish to dark castaneous, including pronotum; pronotal and elytral sides typically same color as disc. Antennae pale brown to castaneous, with darker antennal club; profemora reddish-brown, but meso- and metatibiae, and meso- and metafemora, with mesal and distal portions darker, blackish-brown. Pubescence on pronotum with peculiarly long and recumbent setae, silvery-golden and dense, obscuring dorsal surface at least in posterior half and towards sides, shorter on pronotal disc; elytral pubescence shorter and finer than on pronotum and usually uniformly dispersed, never obscuring dorsal surface.

Dorsal habitus: body rather convex, wide and oval (Fig. 26). Ratio LPR1/LELY = 0.58; ratio WPR1/LPR1 = 1.72; ratio WPR2/LPR1 = 1.76; ratio WPR2/WPR1 = 1.01; ratio LELY/WELY = 0.96; ratio WPR1/WPRA = 1.73; ratio WPR1/WELY = 0.93; ratio WPR2/WELY = 0.94.

Anterior margin of clypeus almost truncate, slightly emarginate; pronotum with blunt but distinct posterior angles (Fig. 26), distinctly projecting backwards. Frons and pronotum with punctures nearly of same size as eye facets, separated by <1 diameter. Elytral punctures markedly finer, shallower and more dense than those on pronotum, smaller than eye facets, oval, separated by <1 diameter, with traces of fine transverse strigosity, more marked around scutellum. Interspaces between punctures on head and pronotum more or less shining; interspaces between elytral punctures more distinctly reticulate and duller. Pygidium with rather dense flatly granular punctures, apex markedly obtusely angulate, prolonged into a distinct, moderately acute process (Fig. 27).

Ventral habitus (Fig. 27): Prosternal process ( Fig. 25 ) subparallel-sided, narrow, roundly pointed distad. Metaventrite exhibiting a marked and deep mediolongitudinal impression, widened behind midlength, markedly convex, densely punctate, shining, at sides duller, without tufts of erect setae (Fig. 27).

Appendages: antennae (Fig. 27) rather long and slender, exhibiting ratio ANLE/HWEA = 1.09; ratio CLLE/ W10J = 1.50; ratio L03J/W03J = 3.00; ratio L03J/L02J = 1.35; ratio L03J/L04J =1.45. Protarsal plates (Fig. 27) moderately wide, ratio WFTA/LFTA = 0.35; protibiae with minute rather sharp teeth on apical third of outer margin (Fig. 27), exhibiting a ratio LETI/WITI ≈ 3.0. Male metafemora exceptionally developed, overtaking elytral sides more than in all other known species of the genus [the ratio between the distal metafemoral portion protruding beyond elytral lateral edge, and head width (HWEA) being more than 0.33× (Figs. 26–27)]; this character state is combined with peculiarly curved and sinuate meso- and metatibiae along their inner edge ( Figs. 23 , 26–27). Metatibiae peculiarly narrow (Figs. 26–27), ratio WPTI/LPTI = 0.23.

Male genitalia: shape of both tegmen and aedeagus as figured ( Figs. 1–2 ), characterized by large, rather long and parallel-sided aedeagus, abruptly narrowed at its distal fifth, with widely spatulate and widened apex, ratio LEAE/WIAE = 2.03. Tegmen wide, widest at distal three fifths, medial distal excision moderately deep, widely pear-shaped (ratio DTIN/LETE ≈ 0.26), inner margins with marked projection; ratio LETE/WITE = 1.46. Main sclerites of internal sac (endophallus) rather long, rod-shaped in both dorsal and lateral view.

Female: Mesotibiae and metatibiae slightly modified (slightly sinuate along inner edge) even in females ( Fig. 24 ). Protarsal plates narrower in female than in male, ratio WFTA/LFTA = 0.24; protibiae slightly more slender in female than in male, ratio LETI/WITI ≈ 3.2. Metatibiae peculiarly narrow ( Fig. 24 ), ratio WPTI/LPTI = 0.21. Pygidium with apex obtusely rounded. In females, metaventrite more flattened or gently depressed behind midlength, but mediolongitudinal line distinctly impressed. Body sizes nearly similar in both sexes (length: 3.4–3.8 mm).

Female genitalia (ovipositor): combined distal apex as figured ( Fig. 21 ), scarcely pointed, distal apex of each gonocoxite transversely truncate (ratio STLE/DSIA ≈ 0.90; ratio STLE/CGOW ≈ 0.12; ratio GONL/CGOW ≈ 1.48). Basal portions of gonocoxites transverse, their laterally directed apices bluntly pointed. Ratio OVPL/GONL ≈ 2.70.

Variation: This species is scarcely variable in body size (length 3.4–3.8 mm, width 1.7–2.0) and body coloration. Ratio LPR1/LELY = 0.57–0.59; ratio WPR1/LPR1 = 1.71–1.74; ratio WPR2/LPR1 = 1.75–1.77; ratio WPR2/WPR1 = 1.01–1.02; ratio LELY/WELY = 0.94–0.98; ratio WPR1/WPRA = 1.73–1.74; ratio WPR1/WELY = 0.92–0.94; ratio WPR2/WELY = 0.94–0.95.

Ratio ANLE/HWEA = 1.06–1.10, ratio CLLE/W10J = 1.48–1.52, ratio L03J/W03J = 3.00–3.10; ratio L03J/ L02J = 1.30–1.40; ratio L03J/L04J =1.42–1.50. Ratio WFTA/LFTA = 0.34–0.36; ratio WPTI/LPTI = 0.23–0.24.

Ratio LEAE/WIAE = 2.02–2.05; ratio DTIN/LETE ≈ 0.25–0.28; ratio LETE/WITE = 1.44–1.50.

Type material. Holotype, ♂: China: Ningxia Hui Autonomous Region, Jingyuan County, Xixia Valley, ca. 1900 m a.s.l., 06.viii.2009, Gu Xin lgt. ( MHBU). Paratypes: 5 ♂, 20 ♀, same data as holotype ( MHBU, NWAFU, IZAS, CAR, NMPC); Shaanxi Province, Ningshan, Huoditang, 18.viii.1998, 1580 m a.s.l., Yuan Decheng lgt., 1 ♂ ( NWAFU); Shaanxi Province, Ningshan, Huoditang, 2200 m a.s.l., 03.viii.1979, Han Yinheng lgt., 1 ♂ ( NWAFU).

Additional studied material almost certainly referable to the same species: China: Ningxia Hui Autonomous Region, Jingyuan County, Erlong River Valley, Ling Chan, Erlonghe Forest Farm, ca. 35.23 ° N, 106.16 ° E, ca. 2200 m a.s.l., 19–20.vii.2008, Wang Xinpu, Ran Hongfan and Wu Qiqi lgt., 2 ♀ ( MHBU).

Distribution. EPA: SHX, SHA.

Meligethes macrofemoratus sp. nov. has an apparently restricted geographic range in central NW China, in middle and middle-high altitude areas at least in the central-northern Shaanxi and in the Ningxia Provinces northwards and eastwards.

Chorotype. Central-NW Chinese.

Host-plants. Unknown. Probably associated with mountain Rosaceae , perhaps Rosa or allied genera.

Habitat. Scrub, middle altitude plains, river edges; at least between 1600–2500 m.

Phenology. VII-VIII.

DNA data. Not available.

Name derivation. Name derived from the peculiarly large and characteristically developed metafemora in males, whose distal portions overtake the lateral elytral edges much more than in any other known species of the genus.

Taxonomic remarks. Meligethes macrofemoratus sp. nov. is member of a small complex of related species mainly distributed in central and southern China, which are easily distinguished by the different shape of male and female genitalia (see Diagnosis above). This species appears to be a geographical vicariant of the three closely related M. auripilis (Yunnan, Sichuan, Gansu, S Shaanxi), M. argentithorax (Qinghai, Sichuan), and M. clinei (Yunnan) , which are distributed from central-southern Shaanxi southwards and westwards.

Figures

FIGURES 1 – 8. Male genitalia of Meligethes spp. 1 – 2: M. macrofemoratus sp. nov. (male paratype from China, Ningxia Hui Autonomous Region, Xixia Valley). 3 – 4: M. clinei Audisio, Sabatelli & Jelínek, 2015 (male holotype from China, Yunnan, Yulong Mts). 5 – 6: M. yak sp. nov. (male holotype from China, Sichuan, Maerkang). 7 – 8: M. nivalis Audisio, Sabatelli & Jelínek, 2015 (male paratype from China, Tibet, Yang Jing). Scale bar = 0.2 mm (Figs. 1 – 8).

FIGURES 17 – 25. Male genitalia of Meligethes spp. 17 – 18: M. aurorugosus sp. nov. (male holotype from China, Tibet, Nyingchi). 19 – 20: M. aurantirugosus Audisio, Sabatelli & Jelínek, 2015 (male holotype from Nepal, W of Chainpur). Distal portion of the ovipositor of Meligethes spp. 21: M. macrofemoratus sp. nov. (female paratype from China, Ningxia Hui Autonomous Region, Xixia Valley). 22: M. scrobescens Chen, Lin, Huang & Yang, 2015 (female from China, Sichuan, Jiuzhaigou Valley). Outline of metatibiae of M. macrofemoratus sp. nov. (male and female paratypes from China, Ningxia Hui Autonomous Region, Xixia Valley). 23: male. 24: female. 25: Prosternal process of M. macrofemoratus sp. nov. (male paratype from China, Ningxia Hui Autonomous Region, Xixia Valley). Scale bar = 0.2 mm (Figs. 17 – 22); = 0.4 mm (Figs. 23 – 25).

FIGURES 9 – 16. Male genitalia of Meligethes spp. 9 – 10: M. aureolineatus Audisio, Sabatelli & Jelínek, 2015 (male from China, Sichuan, Jiuzhaigou Valley). 11 – 12: M. aurifer Audisio, Sabatelli & Jelínek, 2015 (male paratype from China, Shaanxi, Hua Mts). 13 – 14: M. auropilosus sp. nov. (male holotype from China, Tibet, Nyalam). 15 – 16: M. volkovichi Audisio, Sabatelli & Jelínek, 2015 (male holotype from China, Yunnan, Cang Mts). Scale bar = 0.2 mm (Figs. 9 – 16).