Maladera kolkataensis Bhunia, Gupta, Sarkar & Ahrens, 2023

Bhunia, Debika, Gupta, Devanshu, Sarkar, Subhankar Kumar & Ahrens, Dirk, 2023, A new species and new records of Sericini chafers from the Lower Gangetic Plains in India (Coleoptera: Scarabaeidae: Sericinae), Zootaxa 5353 (4), pp. 351-371 : 352-354

Maladera kolkataensis Bhunia, Gupta, Sarkar & Ahrens , new species

( Figs 1–4 , 98 )

Type locality. India: West Bengal, Kolkata, Behala , 22.510N, 88.30E .

Type material. Holotype, male: “ India: West Bengal, Kolkata, Behala , 22.510N, 88.30E, 07.vi.1984, leg. S. Biswas ” ( NZSI).

Description of the holotype, male. Body. Length: 9.2 mm, length of elytra: 5.8 mm, width: 5.1 mm. Body oval, dark black, dorsal surface dull and almost glabrous.

Head. Labroclypeus subtrapezoidal, distinctly wider than long, widest at base, lateral margins weakly convex, moderately convergent anteriorly, anterior angles weakly rounded, margins moderately reflexed; surface convex and less shiny, finely and moderately densely punctate, glabrous except a few single setae anteriorly; frontoclypeal suture distinctly incised, flat and weakly curved; smooth area anterior to eye small, weakly convex, approximately 1.5 times as wide as long; ocular canthus short and broad, finely sparsely punctate, without terminal seta. Frons with sparse punctures, with many long erect setae beside eyes. Eyes large, ratio diameter/interocular width: 0.82. Antenna with ten antennomeres, club with three antennomeres and straight, subequal with length of combined remaining antennomeres. Mentum elevated and slightly flattened anteriorly. Labrum moderately short, transversely rectangular, not produced medially, without median emargination, with densely setose anterior margin.

Pronotum transverse, widest at the base, lateral margins moderately evenly convex and more strongly convergent anteriorly, anterior angles distinctly produced and sharp, posterior angles blunt and weakly rounded at tip; anterior margin convexly produced medially, with a fine complete marginal line; surface moderately densely and finely punctate, glabrous; lateral and anterior border sparsely setose; hypomeron distinctly carinate basally, not produced ventrally. Scutellum broad, triangular, with fine, few punctures, glabrous.

Elytra oblong oval, widest at posterior third, striae finely impressed, finely and densely punctate; intervals nearly flat, with sparse, fine punctures mainly concentrated along striae, glabrous, with a few very long erect setae on penultimate lateral interval; epipleural edge fine, ending at widely rounded external apical angle of elytra, epipleura densely setose, apical border with a fine fringe of microtrichomes (visible at ca 100x magnification).

Ventral surface shiny, finely and sparsely punctate, metasternum glabrous; metacoxa glabrous, with a few single setae laterally; abdominal sternites finely and sparsely punctuate, with a transverse row of coarse punctures, each bearing a short robust seta. Mesosternum between mesocoxae as wide as the mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.31. Pygidium strongly convex and moderately shiny, finely and very densely punctate, without smooth midline, with a few long setae along apical margin.

Legs short; femora shiny, with two rudimentary longitudinal rows of setae, superficially and sparsely punctate, glabrous; metafemur with anterior margin acute, without serrated line adjacent to anterior edge; ventral posterior margin smooth in apical half and only weakly widened, dorsal posterior margin smooth. Metatibia wide and short, widest at apex, ratio of width/length: 1/2.7; dorsal margin sharply carinate, with two groups of spines, basal group shortly before middle, apical group at three quarters of metatibial length, basally with a few short single setae; lateral face weakly convex, finely and sparsely punctate, smooth along the middle; ventral margin finely serrated, with three robust nearly equidistant setae; medial face smooth, apex interiorly near tarsal articulation bluntly truncate. Tarsomeres ventrally with sparse, short setae, dorsal surface smooth, neither laterally nor dorsally carinate; metatarsomeres with a strongly serrated ridge ventrally, glabrous, first metatarsomere distinctly shorter than following two tarsomeres combined and slightly longer than dorsal tibial spur. Protibia moderately long, bidentate, distal tooth simply pointed at apex; anterior claws symmetrical, basal tooth of inner claw sharply truncate at apex.

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

Diagnosis. Maladera kolkataensis Bhunia, Gupta, Sarkar & Ahrens , new species differs from all other Indian Maladera species by the large and strongly bilobed parameres each being divided into a large dorsal and ventral lobe pointed at apex ( Figs. 1–3 ).

Etymology. The new species is named after its type locality Kolkata (adjective in the nominative singular).

Distribution. Only known from the type locality ( Fig. 98 ).

Figures

FIGURE 98. (A–B). A. Gangetic plains biogeographic zone of India; B. Map of Lower Gangetic plains showing sample localities of the species: Maladera kolkataensis, Gynaecoserica perdita, Maladera affinis, M. allopruinosa, M. bengalensi, M. burmeisteri burmeisteri, M. cardoni.

FIGURES 1–12. (1–4). Maladera kolkataensis Bhunia, Gupta, Sarkar &Ahrens, new species (holotype); (5–8). Gynaecoserica perdita Ahrens, 2004 (Kurseong, West Bengal); (9–12). Maladera affinis (Blanchard, 1850) (Purnea, Bihar); (1, 5, 8) 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.