Microplinthus koshianus Meregalli, 2020

Meregalli, Massimo, 2020, Revision of the Nepalese genus Microplinthus Zherichin, 1987 (Coleoptera: Curculionidae: Molytinae), with description of 25 new species, Zootaxa 4794 (1), pp. 1-63 : 49-52

Microplinthus koshianus Meregalli n. sp.

http://zoobank.org/ urn:lsid:zoobank.org:act:83D0AD39-5490-4D36-A390-55C92C3D57FF

Fig. 26

Material examined. Holotype ♂: “ Nepal, Prov. Koshi / distr. Sakhuwasabha / Chichilla, SW, Nebelwald / 27°27.01’N 87°13.13’E / 2040 m NN, 08.XII.1998 / Gesiebe, Leg. M. Hartmann ” ( NMEG)

Diagnostic description. Length 3.92 mm. Body oval, dark ferruginous to blackish, integument glossy. Vestiture composed of relatively numerous thick, spatulate setae, almost perpendicularly inserted on rostrum, on elytral mainly present on tubercles, perpendicularly inserted, recumbent at apex. Rostrum very short, in dorsal view margins weakly broadened at base, linearly narrowed from base to apex, interantennal width 2/3 of width at base, in lateral view thick, very strongly curved basally, apical part less curved, slightly aciculate from base to apex; sculpture deep, composed of 4 longitudinal rows of dense punctures shorter than wide, separated by raised irregular longitudinal keels; apex punctured. Antennal scape sharply and almost angularly broadened at apex, with a few setae directed forwards; funicle antennomere 1 robust, conical, about twice as long as wide, 2 more slender, more than twice as long as wide, 3–5 globose, 6 slightly broader, 7 broader than previous, transverse; club oblong. Eye elliptical, rather acutely pointed in lower part, with about 30 ommatidia. Pronotum longer than wide, subtrapezoidal, sides rather linear from base to apical quarter, then strongly convergent to apex; median keel distinct only in apical half, interrupted before apex; surface with dense punctures irregularly impressed but not merged, interspaces variable, linear or slightly wider, more or less convex. Elytra convex, shortly oval, intervals very irregular, not clearly delimited, with several oval to elongate tubercles, striae 2–4 as broad as intervals, lateral striae broader than intervals, dorsum with small and spaced punctures, irregularly impressed, sides with broad punctures, also irregularly impressed. Femur thickened medially, with a small sharp inner tooth; tibia short, inner margin almost strait, outer margin with long and quite dense raised setae perpendicularly inserted, apex rounded, margin shortly obliquely cut along outer margin of tibia. Tarsomere 3 with lobes well developed, broadly divergent, claws with short and strong inner teeth. Penis moderately and evenly curved downwards, dorsal sides very weakly narrowed towards apical lamella, this short, apex rounded.

Differential remarks. This species lives in the same area as M. arunensis , M. sherpa , and M. khandbariensis . The differences are described in those species’ treatments. Microplinthus koshianus belongs to the Falsanchonus species group, as defined by the phylogenetic analysis (see Discussion and Fig. 1 ), and is morphologically similar to M. bhaktai , differing in the untoothed claws and the apex of the penis being slightly prominent.

Origin of the name. This species name derives from the type locality in the Koshi region .

Distribution. Eastern Nepal, mountains on the east side of the Arun valley, in Koshi region ( Fig. 30 ).

Figures

FIGURE 1. Bayesian Inference consensus tree. Numbers above branches indicate posterior probability. Scale bar unit: expected changes of state per character. The species previously referred to the genera Falsanchonus and Microniphades are indicated.

FIGURE 26. Microplinthus koshianus, Holotype ♂. Body (A, B); rostrum (F, G); antenna (C); pronotum (E); elytra (D); femur (O); foretibia (H); apex of foretibia (J); claws (I); ventrites (N); penis (K, L, M). Bar: 2 mm.

FIGURE 30. Distribution map of some species of Microplinthus. Map data: Google Earth, Maxar Technologies, used according to Google Earth Terms of Service.