Moronoserica songbae Ahrens, Lukic

Ahrens, Dirk, Liu, Wangang, Lukic, Daniel & Bai, Ming, 2023, A taxonomic review of Microserica Brenske, 1894 from continental Asia (Coleoptera: Scarabaeidae: Melolonthinae: Sericini), Zootaxa 5241 (1), pp. 1-115 : 66-67

Moronoserica songbae Ahrens, Lukic & Liu, new species

Figs. 21A–D , 31

Type material examined. Holotype: Ô “W. Thailand: 300m Thung Yai Wildlife Sanctuary, 15°28’N - 98°48’E / Tak Province Umphang District Song Bae Stream. 18-27.iv.1988 / at light / M.J.D. Brendell B.M. 1988-183. / 486 Asia Sericini spec.” ( BMNH).

Description of the holotype. Length: 6.1 mm, length of elytra: 3.8 mm, width: 3.2 mm. Body oval, brown, elytra yellow with numerous dark spots; frons, pronotum and spots on elytra with greenish shine, dorsal surface dull, partly iridescent; labroclypeus simply shiny; pronotum and elytra partly moderately densely covered with white, robust, scale-like setae.

Labroclypeus subtrapezoidal and moderately short, widest at base, lateral margins convex and strongly convergent anteriorly, anterior angles broadly rounded, lateral border and ocular canthus produced into an indistinct obtuse angle, anterior and lateral margins moderately reflexed, anterior margin weakly emarginate medially; surface weakly convex medially and shiny, finely and densely punctate, with numerous long, erect setae; frontoclypeal suture indistinctly impressed and weakly curved; smooth area in front of eye twice as wide as long; ocular canthus short and triangular, almost sparsely finely punctate, with a short single terminal seta. Frons dull, anteriorly narrowly shiny, with fine and moderately dense punctures, beside eyes and behind frontoclypeal suture with a few long erect setae. Eyes small, ratio of diameter/interocular width: 0.57. Antenna yellow, with ten antennomeres; club with four antennomeres subequal in length, club as long as remaining antennomeres combined. Mentum weakly convexly elevated anteriorly.

Pronotum wide, widest at middle, lateral margins convex and convergent anteriorly and posteriorly, anterior angles moderately produced and acute, posterior angles convex; anterior margin convexly produced medially, with a distinct and fine marginal line, basal margin without marginal line; surface with dense and fine punctures, on disc and lateral portions with adpressed white, partly scale-like setae; anterior and lateral borders sparsely setose; hypomeron weakly carinate, carina not produced ventrally. Scutellum narrow and short, with fine and dense punctures, impunctate along midline, with minute setae in punctures.

Elytra short oval, widest at middle, striae finely impressed and finely densely punctate, intervals moderately convex and finely punctate, punctures concentrated long striae, with a few long white setae on odd intervals, and on lateral intervals with sparse small, white setae; interior apical angle of elytron with a robust seta; margins, smaller spots on odd intervals, and a glabrous large spot before apex dark; epipleural edge robust but convex, ending at strongly convex external apical angle of elytra; epipleura densely setose, apical border broadly membraneous, with a rim of short microtrichomes.

Ventral surface dull, with fine and dense punctures, with dense short setae, setae adpressed; metacoxa minutely setose, laterally with robust adpressed setae; each abdominal sternite with indistinct transversal row of coarse and dense punctures, sternite bearing short strong setae between fine and dense punctation, all sternites bearing minute white setae. Mesosternum between mesocoxae almost as wide as mesofemur. Ratio of length of metepisternum/ metacoxa: 1/1.49. Pygidium weakly convex, with fine and dense punctures bearing fine white setae, on apex with numerous long, fine setae, without smooth midline.

Legs moderately slender; femora on ventral surface dull, finely and moderately densely punctate, glabrous, with two longitudinal rows of setae; anterior edge of metafemur acute, with a robust adjacent continuously serrated line, posterior margin weakly convex and glabrous, ventrally weakly widened in apical half but not serrate, posterior margin dorsally not serrate. Metatibia moderately slender and long, dorsal and ventral margin almost subparallel, ratio width/ length: 1/3.4, dorsally longitudinally convex, with two groups of spines, the basal group at one third, apical one at four fifths of metatibial length, basally with a few single spines in the punctures; lateral face longitudinally convex, with dense and moderately coarse punctures, with minute setae, before the basal group of spines without serrated line; ventral margin sharp and serrated, with four robust and long, equidistant spines; medial face impunctate and smooth, apex interiorly (near tarsal articulation) distinctly truncate. Tarsomeres dorsally glabrous and impunctate, ventrally with a very few sparse, short setae. Metatarsomeres ventrally with a single strongly serrated carina, a subventral carina lacking; first metatarsomere as long as following two tarsomeres combined and twice as long as dorsal metatibial spur. Protibia short, bidentate, protarsal claws symmetrical.

Aedeagus: Figs. 21A–C . Habitus: 21D. Female unknown.

Diagnosis. Moronoserica songbae Ahrens, Lukic & Liu, new species differs from all other species of Moronoserica by the relatively small dorsomedian emargination of phallobase which is in this species almost only half of the phallobasal length; in all other species the dorsomedian emargination is reaching almost the phallobasal apodeme (Ahrens 2006).

Etymology. The name of the new species (noun in apposition) is derived from the type locality of the species, Song Bae stream.

Figures

FIGURE 21. A–D: Moronoserica songbae Ahrens, Lukic & Liu, new species (holotype); E–I: Mor. thungyai Ahrens, Lukic & Liu, new species (holotype). A, E: Aedeagus, left side lateral view; C, G: Aedeagus, right side lateral view; B, F: Parameres, dorsal view; D, H: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 31. Distribution of the genus MoronosericaAhrens, Lukic & Liu, new genus.The unlocalized records of Moronoserica helferi (Bohacz & Ahrens, 2020) and Mor. tenasserimensis (Bohacz & Ahrens, 2020) from Myanmar are not shown here.