Maxwelleus tibetanus Meregalli, 2022

Abstract, Massimo Meregalli, 2022, Maxwelleus, a new genus of Curculionidae from the Himalayas, with two new species (Coleoptera: Curculionidae: Molytinae: Euderini), Zootaxa 5105 (2), pp. 281-288 : 283

Maxwelleus tibetanus Meregalli sp. n.

Fig. 1 , Fig. 2 (a, c, e–g, l)

http://zoobank.org/ urn:lsid:zoobank.org:act:D9C0D0D2-5C2B-47AF-92B8-CB4329410755

Type locality: Tibet, Zayul , 28°39'N 97°28'E .

Holotype ♂. China, Tibet. "S.E. Tibet / Zayul [28°39'N 97°28'E] / 7–10000 ft. / vi.1935 // R. J.H. Kaulback / B.M. 1937/547" ( NHMUK).

Description.

Length of the holotype 12.5 mm.

Integument black, matt, very finely, densely microsculptured, elytra with narrow transverse patches of yellow scales. Rostrum robust, epifrons convex, with dense round punctures individually impressed, irregularly aligned longitudinally, with narrow, vaguely delimited longitudinal lines; lateral margins (upper margin of scrobes in dorsal view) slightly broadened at base, moderately linearly narrowed anteriad; in lateral view rostrum strongly regularly curved from base to apex, sides of epifrons densely punctured, punctures similar to those on dorsum; upper margin of scrobes linearly directed towards middle of eye, almost reaching eye, lower margin parallel to upper margin, directed towards underside of eye, interrupted distant from eye; sides below antennal insertion with sparse small punctures; all rostral punctures bearing minute erect seta barely distinct in profile. Antennal scape straight, narrow, thickened near apex; antennomeres 1 and 2 of funicle elongate, about 2.5x as long as wide, antennomere 2 less broadened before apex, antennomeres 3–7 moniliform, approximately as long as wide, 7 slightly larger, more distinctly setose; club densely setose, oval. Vertex and forehead smooth, with few minute distantly spaced punctures, interspaces between two punctures distinctly broader than punctures. Pronotum slightly longer than wide, ratio length/width 1.1, sides linearly moderately broadened from base to apical quarter, ratio width at base / maximum width 0.85, sharply narrowed towards deeply impressed transverse preapical constriction, apical part beyond constriction sharply separated from dorsum, forming annular thick anterior edge; base straight, apex narrowly sinuate at middle; sculpture different in basal and apical parts, basal part with irregular obtuse convexities and narrow impressions, disc towards transverse impression with irregular obtuse tubercles, partly merged with one another, with narrow pit on top; median line broad, obtusely raised, distinct from midlength to transverse groove; apical part smooth, regularly sparsely punctured. Elytra elongate, base straight, sides almost subparallel to apical quarter, ratio width at base / maximum width 0.88, regularly rounded at apex; dorsum flat, intervals 3 and 5 barely convex, interval 1 and even-numbered intervals with small, distantly spaced granules, odd-numbered intervals with dense, closely spaced small barely raised granules, all granules with minute seta; striae not impressed, composed of small shallow punctures; vestiture composed of transverse patches of densely packed yellow oval scales distributed on odd intervals, extending between adjacent striae, two along each interval, one at 1/3 of length, one before declivity, not transversely aligned. Legs slender, femora densely punctured, moderately inflated at midlength, with barely distinct minute median keel; all punctures round, with curved, prominent seta inserted at base; tibiae with oblong, deeply impressed punctures, partly merged in short rows, with short straight setae, inner margin feebly broadened medially, all tibiae with apex distinctly sinuate, with long dense setae; tarsi slender, tarsomere 1 inflated apically, 1.5 as long as wide, 2 triangular, as long as wide, 3 1.5x as long as 2, with lobes elongate, scarcely widened laterally, symmetrical, onychium longer than tarsomeres 2+3 together, broadened from base to apex; claws robust, long, each with inner tooth strongly developed, wide, as long as 2/3 of claw length. Ventrites smooth, 1 with slightly irregular surface, particularly in basal part and near metaventral process, with poorly delimited punctures, 2 glossy, with shallow, closely spaced punctures, 3 and 4 glossy, impunctate, 5 with dense round deeply impressed punctures in line from midlength towards apex, median part near apex with distinct impunctate impression; all punctures with short seta. Aedeagus with penis flat, lamina scarcely curved, apex broadly rounded, tegmen with parameroid lobes moderately developed, thickened.

Derivation of the name. Named after the country of origin, Tibet.

Distribution. The only known specimen was found in southern Tibet, on the northern side of the watershed separating Tibet from Myanmar. The elevation indicated on the label is between 7000 and 10000 feet.

Figures

FIG. 1. Maxwelleus tibetanus, Holotype. Body, dorsum (a), profile (b); rostrum, dorsum (e), profile (h); antenna (i); pronotum (c); elytra, base (d); elytral scales, detail (f); protarsus (g); claws (l); ventrites (j); ventrite 5 (k). Bar: 10 mm. Not to scale.

FIG. 2. Maxwelleus birmanus, Holotype. Body, dorsum (a), profile (b); rostrum, dorsum (e), profile (f); antenna (i); pronotum (c); elytra, base (d); prosternum (g); protarsus (h); claws (l); ventrites (j); ventrite 5 (k). Bar: 10 mm. Not to scale.