Helophorus (Helophorus s. str.) dracomontanus, Angus, Robert B., 2017

Angus, Robert B., 2017, A remarkable new Helophorus species (Coleoptera, Helophoridae) from the Tibetan Plateau (China, Sichuan), ZooKeys 718, pp. 133-137 : 134-136

Helophorus (Helophorus s. str.) dracomontanus sp. n.

Differential diagnosis.

Placed in the subgenus Helophorus s. str. because of its scutellary striae on the elytra, and elytral flanks clearly narrower than the epipleurs opposite the metaventrite. Distinguished from all known species of Helophorus s. str. by the short metallic black maxillary palpi with their apical segments almost symmetrical. The other known species of Helophorus s. str. with dark maxillary palpi with almost symmetrical apical segments ( H. (H. s. str.) niger J. Sahlberg, 1880 and H. (H. s. str.) khnzoriani Angus, 1970) have the palpi longer and their pronota totally devoid of granules.

Description.

General appearance: Fig. 1a; Head and pronotum: Fig. 1b; Underside of lateral area of pronotum: Fig. 1c. Ventral view of elytra, metaventrite and abdomen: Fig. 1d; Basal part of elytra: Fig. 1e, f.

Length: 4.3-4.4 mm; breadth: 1.9 mm. Metallic black, elytra with dark brown undertone and legs dark brown.

Head: strongly granulate, slightly shining with dark green-bronze reflection. Stem of Y-groove narrow linear, 2 × wider than arms. Maxillary palpi metallic black with dark brown undertone, short, apical segment almost symmetrical oval. Antennae 9-segmented, brownish black, clubs darker.

Pronotum: widest about a fifth of the way from the anterior margin, abruptly narrowed anteriorly with the sides sinuate just behind anterior angles, but almost straight behind widest point, convergent to hind angles. Moderately arched, middle portion of internal intervals somewhat bulging, outer part of middle intervals and inner part of external intervals somewhat depressed. Granulation somewhat reduced on middle part of internal intervals, stronger on middle intervals and coarse on externals. Grooves shallow, mid groove over most of its length as wide as the diameter of 3 punctures, tapered to a point anteriorly, slightly constricted but parallel-sided in basal quarter. Floor of groove shining with a few small sparse punctures. Submedian grooves about half width of mid groove, angled outwards medially, reflexed a quarter of the way from each end. Floors shining, rugulose. Submarginals about as wide as mid groove, their sides irregular, floors rugose, shining. Marginal grooves narrow, effaced in anterior quarter. Narrow raised margins finely crenulate. Underside of pronotum with shining suprapleural area narrow at front, widest in anterior quarter, then evenly narrowed to hind angles.

Elytra: widest just behind middle, then tapered to rounded apex. Striae weakly impressed - strial punctures strong but not connected by grooves. Interstices flat with one or two rows of fine punctures, but interstices 1-3 rugose over basal quarter. Scutellary striae of 3-4 punctures, partly concealed by the rugosity. Surface of elytra with a V-shaped depression over basal quarter. Interstice 11 strongly keeled, flanks opposite the metaventrite about three quarters the width of the epipleurs.

Abdomen: ventrites black with erect pubescence. Apical margin of sternite 7 not denticulate.

Legs: dark brown, tarsi blackened apically. Rather short, tarsal hairs indistinct.

Holotype.

♀, CHINA, Sichuan. Kangding County. Yalashenshan 30°12'17.22"N 101°45'17.82"E. Small pools 4074 m a.s.l. (Fig. 2), R. B. Angus, F.-L. Jia & K. Chen. 27.vi.2016. In the Museum of Zoology, Sun Yat-sen University, Guangzhou, China (SYSU).

Paratype.

♀, data as holotype. In the Natural History Museum, London (BMNH).

Derivation of the name.

dracomontanus - Latin, mountain dragon. The species is named after Dr Fenglong Jia. The first part of his name, Feng - phoenix, is a Chinese homophone of Feng - mountain peak. The second part, Long, is straightforward - dragon.