Laccobius (Glyptolaccobius) qinlingensis, Jia, Fenglong, Gentili, Elio & Fikáček, Martin, 2013

Jia, Fenglong, Gentili, Elio & Fikáček, Martin, 2013, The genus Laccobius in China: new species and new records (Coleoptera: Hydrophilidae), Zootaxa 3635 (4), pp. 402-418 : 403-406

Laccobius (Glyptolaccobius) qinlingensis sp. nov.

( Figs. 1–7 )

Type locality. China, Shaanxi Province, Qinlingshan Mts., Fengyukou, 34°01.4ʹN 108°49.2ʹE, 580 m a.s.l. (the series including the holotype, collected by the first author, was taken simultaneously and in the same spot that was collected by Balke & Hájek, hence we provide the complete data on the type locality combining the label data of both these series).

Type material. Holotype: ♂ (SYSU): CHINA, Shaanxi, Qinling, Qinlingliang, Fengyukou, 12.v.2011, lgt. Fenglong Jia [transcribed from Chinese]. Paratypes (58): 32 spec. (SYSU): same data as the holotype; 2 spec. (MSNV): China, Shaanxi, Prov. / Huashan, rock of old road / 12.v.2011 / Fenglong Jia leg.; 9 spec. (NMPC, MSNV): CHINA: Shaanxi prov. 12.v.2011 / ca. 30 km SSW of Xian / Qinlingshan Mts., Fengyukou / (wet cliff, waterfall), 34°01.4ʹN / 108°49.2ʹE, 580 m / M. Balke & J. Hájek lgt.; 12 spec. (NMPC, MSNV): CHINA: Shaanxi Prov. 10.v.2011 / 110 km NNE Xian, Huayin vill. / Hua Shan Mt. (river valley), / ca. 530 m, 34°31.2ʹN 10°04.6ʹE / M. Balke & J. Hájek lgt.; 3 spec. (NMPC): CHINA: Shaanxi prov., 8–9.v.2011 / 110 km NEE Xian, Huyain vill. / Hua Shan Mt. (granite cliff) / 1275 m, 34°29.5ʹN 110°05.1ʹE / M. Balke & J. Hájek lgt.

Description. Total length 2.7–2.9 mm (holotype: 2.8 mm), total width 1.4–1.5 mm (holotype: 1.5 mm). Body oval, moderately convex, maximum width in anterior elytral third. Total length / total width ratio = 1.9. Dorsal surface finely pubescent.

Head. Coloration black, without pale preocular spots, surface with dense and coarse punctures, without microsculpture; ‘systematic punctures’ indistinct; periocular sulci vaguely defined, reaching anterolateral branches of frontoclypeal suture. Labrum blackish, about 2.3× as wide as long, without specula in both sexes; anterior margin very feebly emarginated medially; lateral portions sharply angulated. Anterior margin of clypeus deeply excised. Eyes oblong, oblique, closest to each other posteriorly, slightly protruding laterad, separated by distance equal to 2.35× of width of one eye in dorsal view; posterior margin of eye nearly straight in dorsal view, distinctly reniform in lateral view; postocular portion of tempora short. Mentum strongly rugose, bearing few coarse punctures, not emarginate anteriorly. Submentum not microgranulate. Gula microgranulate, gular sutures widely separated, tentorial pits moderately large, very distinct. Maxillary palpi yellowish brown, dark at apex; palpomere 1 thin and short; palpomeres 2 and 3 nearly equal in length, palpomere 3 dilated at apex; palpomere 4 elongate, nearly 1.4× as long as palpomere 3, asymmetrical, inner margin straight and outer margin convex, apex truncate. Antenna with eight antennomeres; scape (antennomere 1) longer than antennomeres 2–4 combined; pedicel (antennomere 2) cone-shaped; two intermediate antennomeres (antennomeres 3–4) very short; cupule (antennomere 5) asymmetrical, oval in ventral view, crescent-shaped and emarginate in dorsal view; antennal club loose, bearing densely arranged setae, antennomeres 6 and 8 nearly equal in length, antennomere 6 widest, antennomere 7 shortest and narrowest.

Thorax. Pronotum transverse, slightly impressed sublaterally, 0.4× as long as wide; black with yellowish lateral margins; yellow area about 0.5× as wide as posterior margin of eye along base, sometimes yellow edge vaguely defined from black disc; surface smooth as that on head, without microsculpture; punctures coarse and dense, bearing decumbent whitish setae. Prosternum black, tectiform, with longitudinal keel. Scutellar shield equilaterally triangular, black, with few punctures. Mesoventrite with longitudinal, anteriorly arrow-shaped keel. Elytra combined slightly elongate, ca. 1.2× as long as wide, blackish with yellowish lateral margins and apices; without pale yellow basal spot; 10 longitudinal rows of regularly impressed primary punctures alternating with 10 rows (interstriae) of sparser and more or less irregular secondary punctures; secondary punctures of same size as primary punctures; all punctures bearing long whitish semierect setae. Parasutural furrow reaching anterior third of elytral length, very conspicuous on posterior elytral third and elytral apex. Epipleura and pseudoepipleura oblique, nearly vertical. Metaventrite setiferous with an oval median glabrous area and a longitudinal sulcus posteromedially.

Legs. Procoxae and trochanters pubescent; profemora setiferous on basal half, smooth distally, with tibial grooves; protibiae smooth, each bearing stiff setae and two apical spurs. Mesofemora smooth, with tibial grooves; ventral side of mesotibiae with three longitudinal rows of stiff setae and sulcus between two longitudinal ridges. Metatrochanters smooth and shining, only very finely pubescent mesally; metafemora smooth, each with scarce punctures and tibial grooves; metatibiae curved, ventral side of each tibia with three longitudinal rows of stiff setae and longitudinal sulcus between two ridges. Natatory setae nearly absent on dorsal surface of tarsi. Metatarsi with second tarsomere as long as third and fourth combined; fourth metatarsomere about 0.65× as long as third tarsomere.

Abdomen. Ventrites 1–4 smooth, without microsculpture, with transverse series of setae; last two ventrites densely pubescent.

Aedeagus ( Figs. 3–5 ). Total length 0.6 mm. Parameres nearly 1.65× as long as phallobase. Median lobe almost as long as parameres, with a series of stout spines laterally, its apex rounded, subdivided medially.

Differential diagnosis. Laccobius qinlingensis sp. nov. is easily distinguished from other species of Glyptolaccobius by the combination of following characters: body large (2.7–2.9 mm long); head without preocular spots; pronotum with pale lateral margins; mesoventrite with longitudinal keel, arrow-shaped anteriorly; parasutural stria of elytra distinct, reaching anterior third of elytral length; elytra with 10 rows of distinct primary punctures and somewhat irregular secondary rows of punctures that are of the same size as primary rows; lateral margins of elytra and elytral apex pale; pale spots near scutellum absent; elytral rows of punctures not sulciform; mentum rugose. Besides the external characters, Laccobius qinlingensis sp. nov. differs from all Glyptolaccobius by the median lobe bearing lateral subapical rows of stout spines ( Fig. 3, 5 ). These spines are unique for L. quinlingensis ; no similar structure is known in any other Laccobius species except L. (Yateberosus) elevatus Fauvel, 1883 from New Caledonia, although the spines are much thinner in that species (for details, see Gentili 1988).

The key to the species of the subgenus Glyptolaccobius published by Gentili & Fikáček (2009) should be modified as follows:

4. Entire elytra shining black, without yellow lateral margins. Apex of median lobe widely expanded (Gentili & Fikáček 2009: Fig. 4 ). Body length 2.3–2.5 mm ........................................ L. moriyai Kamite, Ogata & Hikida, 2007 – At least lateral margins and apex of elytra yellowish. Apex of median lobe widened or not. Body length less than 2.3 mm or more than 2.7 mm .................................................................................... 4a 4a. Body length 2.7–2.9 mm. Posterior pronotal margin yellowish laterally, median lobe somewhat widened before apex, with a series or large spine-like projections laterally ( Figs. 3, 5 ).................................... L. qinlingensis sp. nov. – Body length smaller than 2.3 mm. Posterior pronotal margin yellowish or entirely black, median lobe without a series of spinelike projections laterally................................................................................ 5

Etymology. The species name refers to the Qinlingshan Mts. in which all known localities of this species are situated.

Biology. Part of the type series was collected on wet granite rocks at the bottom of the waterfall in Fengyukou ( Fig. 6 ) or in small hygropetric “streamlets” flowing over the granite cliffs of the Huashan Mts. near Huayin village ( Fig. 7 ) (in the latter case together with Aspidytes wrasei Balke, Ribera & Beutel, 2003 (Adephaga: Aspidytidae )). Second part of the type series (in Fengyukou and in river valley near Huayin village) was collected on wet rocks at sides of the roads (the rocks were exposed during the construction of the road).

Distribution. Only known from three localities in the granite massif of the Qinlingshan Mts.

Figures

FIGURES 1 – 7. Laccobius (Glyptolaccobius) qinlingensis sp. nov. and its localities. 1 – 2: general habitus (1: dorsal view; 2: lateral view). 3 – 5: aedeagus (3: dorsal view; 4: lateral view; 5: ventral view). 6: waterfall at Fengyukou, type locality, site where the specimens were collected is marked by an arrow. 7: M. Balke collecting L. qinlingensis and Aspidytes wrasei at a granite cliff near Huayin village. Photos 6 – 7 by J. Hájek.