Microserica nicobarensis ( Redtenbacher, 1868 )

Bhunia, Debika, Gupta, Devanshu, Chandra, Kailash & Ahrens, Dirk, 2021, New species and records of Sericini of India (Coleoptera: Scarabaeidae Melolonthinae) II., Zootaxa 5081 (4), pp. 594-600 : 595-596

Microserica nicobarensis ( Redtenbacher, 1868)

( Figs. 1–4 )

Serica nicobarensis Redtenbacher, 1868: 64 .

Microserica nicobarensis: Brenske 1898: 375 .

Type locality. “ Sambelong” [ India: southern group of Nicobar Islands]. In the original description no type locality was given. We adopted it from the locality label associated with the lectotype .

Type material examined. Lectotype (here designated), ♂: “ Microserica nicobarensis / Nicobarensis Sambelong Redt. / Serica nicobarensis Typ. Redtb. / nicobarensis Redt Type [handwritten Brenske]” ( NHMW).

Additional material examined. 3 ♂♂ “ India: Andaman , Great Nicobar, South Bay, 11.643300N, 92.724050E, 20.viii.1984, leg. S. S. Saha ” ( NZSI) .

Redescription. Body. Length: 7.7 mm, length of elytra: 5.4 mm, width: 6.2 mm. Body oblong-oval; dorsal face dark brown; ventral face dark reddish–brown dull; head moderately shiny, surface glabrous, except few single setae.

Head. Labroclypeus narrow and trapezoidal, widest at base; lateral margins straight and convergent anteriorly; anterior angles strongly rounded; anterior margin distinctly emarginate medially, margins moderately reflexed. Antennae with ten antennomeres; club with four straight antennomeres, almost equal with remaining antennomeres combined. Lateral margin and ocular canthus produced into a distinct angle, surface flat, finely and densely punctate. Frontoclypeal suture indistinctly incised, evenly curved. Smooth area anterior to eye weakly convex, twice as wide as long; ocular canthus short and moderately narrow (1/4 of ocular diameter), finely and densely punctate, terminal seta absent. Mentum elevated and slightly flattened anteriorly. Frons with dense but fine punctures and with a single, long seta beside eyes. Eyes small, ratio diameter/interocular width: 0.8.

Pronotum transverse, widest shortly before base; lateral margins evenly convex and strongly convergent anteriorly, slightly convexly narrowed towards base; anterior angles distinctly produced and sharp; posterior angles strongly rounded; anterior margin convex, with complete but indistinct marginal line; base without marginal line; surface densely and finely punctate, punctures less dense on midline, with minute setae in punctures; anterior and lateral margin finely setose; hypomeron carinate, not produced ventrally. Scutellum wide, triangular, with fine and dense punctures, punctures less dense on basal midline.

Elytra widest at middle; striae distinctly impressed, finely and sparsely punctate; intervals slightly convex, with fine and dense punctures, with minute setae in punctures; odd intervals with a very few short and white setae; epipleural edge robust, ending at strongly curved external apical angle of elytra; epipleura sparsely setose; apical border of elytra membranous, with a fine rim of microtrichomes.

Ventral surface dull, coarsely and densely punctate, glabrous. Metasternal disc sparsely covered with fine, short setae. Metacoxa with a few longer setae laterally. Abdominal sternites finely and densely punctate, sternites with a transverse row of punctures, punctures bearing a fine seta. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/2.1. Pygidium moderately convex and dull, coarsely and densely punctate, without impunctate midline, glabrous except a few robust setae along apical margin.

Legs moderately long and wide, shiny; femora with two longitudinal rows of setae, finely and sparsely punctate. Metafemur with anterior margin acute, without adjacent serrated line, but with few sparse setae; posterior margin smooth, weakly widened at apex, smooth at apex ventrally. Metatibia long and wide; widest at middle, sharply carinate dorsally, with two groups of spines, longer at basal group at anterior third, smaller at apical group at threequarters of metatibial length, ratio of width/length:1/2.56; lateral face longitudinally convex, shiny, impunctate and glabrous; ventral margin densely serrate, with four equidistant long and robust setae; medial face smooth and glabrous; apex finely serrate, moderately truncate interiorly near tarsal articulation. Tarsomeres dorsally impunctate, glabrous, neither laterally nor dorsally carinate, moderately setose ventrally; metatarsomeres with a strongly serrated ridge ventrally and a smooth subventral longitudinal carina; first metatarsomere as long as following two tarsomeres combined and slightly longer than dorsal tibial spur. Protibia moderately long, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus. Figs. 1–3 . Habitus. Fig. 4 . Female unknown.

Distribution ( Fig. 13 ). The species is only known from the Nicobar island.

Remark. Since no number of examined specimens was given in the original description, we designate here the examined syntype as lectotype of the species.

Figures

FIGURE 13. Map of India showing type localities of the species.

FIGURES 1–12. 1–4. Microserica nicobarensis (Redtenbacher, 1868); 5–8. Maladera reyaensis Bhunia, Gupta, Chandra & Ahrens, new species; 9–12. Nepaloserica cheemaensis Bhunia, Gupta, Chandra & Ahrens, new species. (1, 5, 9) Aedeagus in lateral view (left); (2, 6, 10) Aedeagus in dorsal view; (3, 7, 11) Aedeagus in lateral view (right); (4, 8, 12) Habitus, dorsal view. Scale 0.5 mm; habitus not to scale.