Maxwelleus birmanus 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 : 285

Maxwelleus birmanus Meregalli sp. n.

Fig. 2 , Fig. 3 (b, d, h–j, k, m)

http://zoobank.org/ urn:lsid:zoobank.org:act:B838C32E-3331-458E-9A51-8DCC3429FF38

Type locality: Myanmar, river Nam Tamai , 27°43'N 97°52'E .

Holotype ♂. Burma, Kachin province. " Upper Burma: / R. Tam Tamai / [= River Nam Tamai , approx. 27°50’N 97°41’E] 4000 ft. / 13.ix.1937 / F. Kingdon-Ward " ( NHMUK). This specimen lacks the hind right leg and some tarsomeres.

Description.

Length of the holotype 13.8 mm.

Integument black, matt, very finely and densely microsculptured, elytra with sparse narrow transverse patches of yellow scales. Rostrum robust, dorsum of epifrons convex, with round punctures individually impressed, irregularly aligned longitudinally, with longitudinal lines as wide as punctures, median line distinct; lateral margins (upper margin of scrobes in dorsal view) weakly curvilinear from base to midlength, moderately narrowed anteriad; in lateral view rostrum regularly curved from base to apex, sides of epifrons sparsely punctured, punctures narrower than those on dorsum, leaving smooth impunctate longitudinal line; upper margin of scrobes linearly directed towards middle of eye, interrupted quite far from eye, lower margin directed towards underside of rostrum, approaching upper margin posteriad, interrupted behind midlength; sides below anterior part of scrobes with dense large punctures; rostral punctures bearing minute setae, not visible outside puncture in profile. Antennal scape straight, narrow, thickened near apex; antennomeres 1 and 2 of funicle elongate, about 2.5x as long as wide, antennomere 3 longer than wide, 4–7 moniliform, approximately as long as wide; club densely setose, oval. Vertex and forehead smooth, with few tiny shallow punctures, interspaces among punctures much wider 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 0.87, sharply narrowed towards transverse preapical groove, this deeply impressed only on sides, shallow on dorsum, apical part beyond groove not sharply separated from dorsum of pronotum; base straight, apex narrowly sinuate at middle; sculpture rather uniform in basal and apical parts, surface smooth, lacking tubercles, with minute sparse pits, interspace among pits much broader than pits; median line broad, obtuse, barely distinct from midlength to transverse groove. Elytra elongate, base straight, sides subsinuate behind humeri, weakly curvilinear, maximum width at midlength, ratio width at base / maximum width 0.80, gradually attenuate to apex; dorsum flat, intervals 3 and 5 indistinctly higher than even intervals, interval 1 and even-numbered intervals with sparse distantly spaced small weakly raised granules, narrower than intervals; odd-numbered intervals with slightly denser row of similar granules; all granules bearing minute scarcely distinct seta; striae not impressed, with minute punctures, barely visible, interspace between two punctures twice as long as punctures; vestiture composed of few narrow transverse patches of yellow scales, joining adjacent striae, quite irregularly placed, 3-4 patches on intervals 3, two in basal third, two on declivity, one composed of very few scales, 2-3 patches on other odd intervals; two smaller patches also present on interval 6. Legs slender, femora densely punctured, weakly inflated at midlength, lacking median keel, punctures round, with minute seta not longer than puncture, barely visible in profile; tibiae with oblong, deeply impressed punctures, partly merged in short rows, apex almost straight on inner part, long obliquely cut on outer part in foretibiae, distinctly sinuate in meso- and metatibiae, with dense short straight setae; tarsi slender, tarsomere 1 inflated apically, 1.5x as long as wide, 2 triangular, as long as wide, 3 1.5x longer than 1, with lobes elongate, scarcely widened laterally, slightly asymmetrical, with outer lobe smaller, onychium as long as tarsomeres 2+3 together, broadened from base to apex; claws robust, long, inner tooth strongly developed on each claw, wide, as long as 2/3 of claw length. Ventrites smooth, 1 and 2 with distantly spaced round punctures, 3 and 4 with weakly impressed minute distantly spaced punctures near apex, 5 with sparse punctures smaller than those on ventrites 1 and 2, median part near apex smooth, impunctate; punctures on ventrites 1 and 2 with a short seta. Aedeagus complex with penis convex, lamina curved, apex truncate, tegmen with parameroid lobes slender, elongate.

Derivation of the name. Named after the historical name of the country of origin, Burma, now Myanmar.

Distribution. The only known specimen was found in norther Myanmar, in the valley of the river Nam Tamai during one of the expeditions to the country by Francis Kingdon-Ward. Unfortunately, no precise information on the collecting locality is available, but the elevation indicated on the label suggests that the specimen was found in the median part of the valley.

Figures

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.

FIG. 3. Maxwelleus tibetanus, Holotype. Profemur (a); protibia (c); penis with temones and internal sac (e); penis (f) and detail of apex (g); tegmen (l). Maxwelleus birmanus, Holotype. Profemur (b); protibia (d); penis with temones and internal sac (h); penis (i) and detail of apex (j); tegmen (m); sternum VIII (k). Not to scale.