Microplinthus khandbariensis 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 : 30

Microplinthus khandbariensis Meregalli n. sp.

http://zoobank.org/ urn:lsid:zoobank.org:act:00B86FEE-F501-49D7-A370-6818D473D9AF

Fig. 14

Material examined: Holotype ♂. “ NEPAL. Khand- / bari District // above Sheduwa [= Seduwa, 27°34’N 87°15’E] / 3000 m 31.III / 1.IV.1982 / A. & Z. Smetana // H. & A. Howden / Collection” ( CMNC).

Paratypes: same data as the holotype, 1♀ ( CMNC); “ NEPAL. Khand- / bari District // above Tashigaon [= Tashi Gaon, 27°38’N 87°12’E] / 3200 m 8.IV.1982 / A. & Z. Smetana // H. & A. Howden / Collection” 1♂ ( MER) .

Diagnostic description. Length 4.47 mm, body oval, integument reddish on rostrum and legs and dark reddish on pronotum and elytra, rather glossy. Vestiture composed of sparse short slender setae, appressed to integument, also on elytra. Rostrum stout, weakly broadened apicad, dorsal sides linearly convergent, in lateral view dorsum regularly curved, not more thickened or curved basad, junction with head very slightly concave; in dorsal view punctures small, irregularly aligned, often individually impressed and spaced, longitudinal interspaces among punctures forming narrow, moderately distinct glossy lines; apical part, from slightly beyond antennal insertion to apex, smooth. Antennal scape slender, regularly thickened apicad; funicle antennomeres 1 and 2 slender, 2 about 3 times as long as wide and slightly longer than 1; 3–7 globose, 7th larger than previous and setose; club broadly oval. Eye large, acutely pointed in its lower part, with about 45 ommatidia. Pronotum as long as wide, sides distinctly and regularly curvilinear, apical margin in lateral view almost straight; median keel sharp and distinct for almost entire dorsum, excepting near base; punctures round, dense, deeply impressed, margins of the punctures linear, uniformly raised on the entire perimeter of punctures, in dorso-lateral area interspaces in part more sharply raised on external part, with some smooth, unpunctured glossy areas. Elytra oval, odd intervals with barely distinct low humps or punctured granules, even intervals almost flat; striae with distinct round to subrectangular punctures, isolate, interspaces as long as punctures, often with a trace of small granules between the punctures. Femur slender, scarcely thickened medially, inner tooth scarcely developed; tibia slender, apex rounded, not obliquely cut along the outer margin; claws with sharp, well developed inner teeth. Ventrites 2–5 moderately and regularly restricted on sides, 1 and 2 with dense round punctures, denser on 1 and more spaced on 2; 3–4 with a single row of horizontally aligned punctures; 5 densely punctured. Penis flat in basal half, then strongly curved downwards, lateral sides in dorsal view weakly curvilinear, maximum width slightly after midlenght towards apex, linearly convergent to acute, long prominent apical lamella. Female sternum VIII short, apodeme not distinct, arms not joined basally, branches shirt, perpendicular to plate, arms separated from base, shortly curved laterally, lamina as long as wide, sclerotized part slightly convergent apicad.

Variation. The three specimens exhibit little variation. Body size varies between 4.36 and 4.68 mm.

Differential remarks. The species that live in proximity are M. arunensis , M. koshianus and M. sherpa . All these species have brownish or dark brownish integument. See description of M. arunensis for differentiation with that species; M. koshianus has pronotum prominent above head and rostrum strongly curved, thickened basad and tapered apicad. Microplinthus sherpa has penis and female sternum VIII completely different (see illustrations) and pronotum densely and irregularly sculptured, with anterior margin prominent above head. Microplinthus parbatensis and M. schawalleri have reddish integument, and differ at first sight in the highly raised elytral setae.

Origin of the name. This name derives from the district of Khandbar, in eastern Nepal.

Distribution. Eastern Nepal, found in the mountains on the west of the Arun valley, in Khandbari district ( Fig. 30 ).

Figures

FIGURE 14. Microplinthus khandbariensis, Holotype ♂, paratype ♀. Body (A, B); rostrum (F, G); antenna (C); pronotum (E); elytra (D); femur (O); apex of foretibia (K); claws (L); ventrites (N); penis (H, I, J); female sternum VIII (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.