Paederus (Gnathopaederus) furcillatus, Assing, 2017

Assing, Volker, 2017, Two new species and additional records of micropterous Paederus from China and Taiwan (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 49 (1), pp. 253-263 : 255-259

Paederus (Gnathopaederus) furcillatus nov.sp. ( Figs 1-17 )

T y p e m a t e r i a l: Holotype 3: "S China SE-Guizhou Leishan Xian: Leigong Shan, 1900- 2170 m, V-VI.2012 26°23,187 N 108°12,173 E lgt. M. Hackel & K+R. Sehnal / Holotypus 3 Paederus furcillatus sp.n. det. V. Assing 2015" (cSme). Paratypes: 233, 1♀: same data as holotype (cSme, cAss).

E t y m o l o g y: The specific epithet is an adjective derived from the Latin noun furcilla (fork) and alludes to the shape of the male mandibles.

D e s c r i p t i o n: Body length 11.0- 12.5 mm; length of forebody 5.6-5.9 mm. Coloration: head black; pronotum red to dark-red; elytra metallic-blue; scutellum darkred with the posterior portion infuscate; abdomen bicoloured with segments III-VI palereddish and segments VII-X black; legs blackish-brown with the basal third to two-fifths of the meso- and metafemora reddish; antennae dark-brown with antennomeres I-III and the apical 3-4 antennomeres yellowish-red; maxillary palpi yellowish-red.

Head ( Fig. 1 ) moderately transverse, 1.05-1.12 times as broad as long; punctation moderately sparse and moderately fine, sparse in median dorsal portion; interstices without microsculpture. Eyes approximately half as long as distance from posterior margin of eye to posterior constriction of head. Antenna 3.5-3.8 mm long. Labrum and mandibles with sexual dimorphism.

Pronotum ( Fig. 1 ) approximately 1.15 times as long as broad and 0.87-0.92 times as broad as head, strongly convex in cross-section; punctation sparse and fine, not forming dorsal series; midline broadly impunctate.

Elytra ( Fig. 1 ) 0.63-0.68 times as long as pronotum and slender, approximately as broad as pronotum; humeral angles obsolete; punctation moderately coarse, dense, and somewhat ill-defined; interstices without microsculpture. Hind wings completely reduced. Protarsomeres I-IV moderately dilated, without sexual dimorphism. Metatarsomere I approximately as long as the combined length of II and III.

Abdomen broader than elytra; punctation moderately coarse and moderately dense on tergites III-VI, finer and sparser on tergites VII and VIII; pubescence moderately long and pale; interstices with fine transverse microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII with weakly pronounced sexual dimorphism.

3: anterior margin of labrum with a short blunt tooth on either side of the narrow median notch, laterally weakly sinuate and with a weakly pronounced lateral tooth ( Fig. 9 ); both mandibles with a pronounced erect and broad-based horn ( Fig. 9 ); tergite VIII strongly convex posteriorly; aedeagus ( Figs 2-8 , 13-14 ) 2.00- 2.15 mm long (including parameres); ventral process apically convex, in the middle truncate in ventral view; dorsal plate slightly asymmetric, basally strongly excavate in the middle and with bulging lateral margins, apically extending into a spine-shaped process, apex distinctly curved dorsad in lateral view; internal sac with a long sclerotized spine apically extending nearly to apex of dorsal plate.

♀: anterior margin of labrum with a blunt tooth on either side of the rather broad median notch and with a weakly pronounced lateral tooth ( Fig. 11 ); mandibles with a bifid median molar tooth ( Fig. 11 ); tergite VIII weakly convex or truncate in the middle; posterior margin of sternite VIII with a convex median projection ( Fig. 17 ); sternite IX with weakly concave posterior margin ( Fig. 17 ); tergites IX and X as in Fig. 16.

C o m p a r a t i v e n o t e s: Based on the morphology of the male mandibles, this species belongs to the subgenus Gnathopaederus CHAPIN, 1927 , which previously included eight species, six of them micropterous, distributed in China and Thailand (PENG et al. 2015). Regarding its external and sexual characters (coloration of the legs and antennae; habitus and body proportions; shape of the labrum; general morphology of the aedeagus; shapes of the female sternites VIII and IX), the new species is most similar to P. yunnanensis WILLERS, 2001 from West Yunnan and P. xuei PENG & LI, 2015 from southeastern Yunnan. It differs from both of them as follows:

from P. yunnanensis by the shapes of the male and female labrum ( P. yunnanensis : on either side of the shallower median notch with a less pronounced tooth, laterally with an additional tooth), by the shape of the male and female mandibles ( P. yunnanensis : both male mandibles with a smaller dorsal process, left mandible with a stouter and apically blunter molar tooth; female mandibles with a more broad-based and apically more deeply bifid molar tooth), by the morphology of the aedeagus ( P. yunnanensis : dorsal plate apicad more abruptly narrowed in dorsal view and apically not distinctly curved dorsad in lateral view; parameres apically more gradually narrowed; internal spine shorter, far from reaching apex of dorsal plate), by the less strongly convex posterior margin of the female sternite VIII, and by the less concave posterior margin of the female sternite IX;

from P. xuei by the shapes of the male and female labrum ( P. xuei : laterally with an additional tooth), by the shape of the male and female mandibles ( P. xuei : both male mandibles with a smaller dorsal process, left mandible with a distinctly bifid, less stout molar tooth; female mandibles with a more broad-based and apically more deeply bifid molar tooth), by the morphology of the aedeagus ( P. xuei : dorsal plate apicad more abruptly narrowed in dorsal view; parameres with shorter apices; internal spine much shorter, far from reaching apex of dorsal plate), by the broadly convex posterior margin of the female sternite VIII ( P. xuei : obtusely pointed in the middle), and by the more broadly concave posterior margin of the female sternite IX.

For illustrations of the external and sexual characters of P. yunnanensis and P. xuei see PENG et al. (2015).

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: The type locality is situated in the Leigong Shan, southeastern Guizhou. The specimens were collected at an altitude between 1900 and 2170 m, together with P. parvidenticulatus .

Figures

Figs 1-8: Paederus furcillatus nov.sp.: (1) forebody; (2-4) aedeagus in lateral, ventral, and dorsal view (in transparent light); (5-8) aedeagus in lateral, ventral, and dorsal view (in dry preparation). Scale bars: 1.0 mm.

Figs 9-17: Paederus furcillatus nov.sp.: (9) anterior portion of male head; (10) male labrum; (11) anterior portion of female head; (12) female labrum; (13-14) median portion of aedeagus ventral and in dorsal view (in transparent light); (15) female sternite VIII; (16) female tergites IX and X; (17) female sternite IX. Scale bars: 9, 11, 15-17: 1.0 mm; 10, 12-14: 0.5 mm.