Selasia dembickyi, Kundrata & Sormova, 2018

Kundrata, Robin & Sormova, Eliska, 2018, Selasia dembickyi sp. nov., the first member of Drilini (Coleoptera: Elateridae) from South East Asia, with the description of S. jenisi sp. nov. from Nepal, Acta Entomologica Musei Nationalis Pragae 58 (2), pp. 513-518 : 514

Selasia dembickyi sp. nov.

( Figs 1–2, 5, 7, 9–13 )

Type material. HOLOTYPE: ♂, ‘ THAILAND, Chiang Mai Prov., Pha Hom Pok Mt., 1900–2200 m, 20°02’35’’N, 99°08’45’’E, 23.–30. iv. 2009, L. Dembický leg.’ ( NHMB).

Description of holotype. Body ( Figs 1–2 ) 2.95 times as long as width at humeri; dark brown to black, scapus slightly lighter, prothorax light brown, head and mesothorax light brown to brown; body surface covered with yellowish semi-erect pubescence.

Head ( Fig. 1 ) including eyes 0.75 times as wide as pronotum, surface smooth, with shallow median depression between antennal insertions, sparsely and finely punctate, covered with sparse, long, semi-erect pubescence. Fronto- clypeal region relatively wide, flattened, almost vertically sloping to base of labrum. Eyes large, their frontal distance 1.35 times eye diameter. Labrum transverse, almost smooth, finely punctate, with anterior margin slightly emarginate. Mandibles robust, long, bidentate; base with long setae, apical part bare, shiny. Maxillary palpi slender, penultimate palpomere shortest, slightly longer than wide, apical palpomere more than twice as long as penultimate palpomere, widened medially, apically flattened, obliquely cut.Antenna ( Fig. 5 ) with 11 antennomeres, flabellate; scape robust, gradually widened apically, pedicel short, only slightly longer than wide; length ratio of antennomeres II– IV 1.00: 2.00: 1.35; antennomere III elongate, with short triangular branch, shorter than stem; antennomeres IV–X short, subequal in length, with long, flattened branches, branches about three times as long as their stems; ultimate antennomere simple, longest, slightly longer than branch of penultimate antennomere; all antennomeres covered with moderately dense pubescence.

Pronotum ( Fig. 7 ) slightly convex, widest at posterior angles, 1.90 times as wide as long. Anterior margin almost straight, slightly emarginate medially, lateral margins slightly sinuate, posterior margin simple, widely emarginate medially. Anterior angles inconspicuous; posterior angles short but prominent, apically narrowly rounded, produced postero-laterally. Lateral pronotal carina almost complete. Surface of disc smooth, rugose at posterior angles; sparsely shallowly punctate, with sparse semi-erect pubescence, longer at posterior angles. Hypomeron smooth. Prosternum transverse, medially transversely deeply grooved, with long semi-erect setae; prosternal process reduced.

Scutellar shield flat, tongue-like, slightly longer than wide, widest near base, then gradually distinctly narrowed toward apex; sparsely punctate, anterior margin gradually declivitous, posterior margin rounded. Mesoventrite widely v-shaped, with frontal margin widely concave; mesoventral cavity very shallow. Elytra ( Figs 1–2 ) subparallel-sided, both combined 2.10 times as long as wide, 0.70 times as long as body, 5.20 times as long as pronotum, slightly rugose, without distinct striae, with apices separately rounded, sparsely and finely punctate, covered with long, semi-erect pubescence.

Legs slender, slightly compressed, with sparse, long, semi-erect setae; tarsomere I slightly shorter than tarsomere II, widened apically, tarsomere II elongate, slightly longer than tarsomere III, tarsomere IV shortest, minute, lobed ventrally, apical tarsomere slender, elongate; claws simple, slender, slightly curved, each with long seta basally.

Abdomen soft, ventrites with sparse shallow punctures, covered with semi-erect pubescence, denser at margins; penultimate ventrite widely emarginate medially. Tergite IX ( Fig. 10 ) transverse, less than twice as wide as long; tergite X ( Fig. 11 ) about as long as wide, apically rounded and partly membranous, sparsely covered with short setae. Sternite IX ( Fig. 9 ) about 1.6 times as long as wide, narrowed and not emarginate basally, rounded apically, apex finely punctate and sparsely setose.

Male genitalia ( Figs 12–13 ) twice as long as maximum phallobase width; median lobe narrow, elongate, about 1.6 times as long as phallobase, distinctly longer than parameres, curved in lateral view, basally with two short struts, dorsally with short sharp subapical hook; parameres distinctly elongate, apically partly membranous, with sparse long setae; phallobase short, v-shaped, slightly wider than long.

Measurements. BL 6.60 mm, WHum 2.25 mm, EL 4.70 mm, WHe 1.30 mm, PL 0.90 mm, PW 1.70 mm, Edist 0.70 mm, Ediam 0.55 mm.

Differential diagnosis. Selasia dembickyi sp. nov. is the only Drilini species known from South East Asia. It can be recognized by the following combination of characters: head and pronotum lighter than rest of body ( Figs 1–2 ), weakly flabellate antennae ( Fig. 5 ), strongly sinuate pronotal sides with distinctly diverging posterior angles ( Fig. 7 ), and base of sternite IX not emarginate ( Fig. 9 ). This species has uniquely shaped male genitalia among Drilini ( Figs 12–13 ) with a very long and narrow median lobe, which is distinctly longer than the parameres, elongate parameres which are widest at the second third, and the phallobase which is short compared to the median lobe and parameres.

Etymology. The specific epithet is a patronym in honor of Luboš Dembický (Brno, Czech Republic), the collector of the holotype.

Collecting circumstances. Members of Selasia are usually collected at light or using Malaise traps (e.g., WITTMER 1989; KUNDRATA 2012a, 2017; TRLLOVA & KUNDRATA 2015). The exact collecting circumstances for S. dembickyi sp. nov. are not known but it was most probably collected at light or using a flight interception trap (L. Dembický, personal communication). The habitat of this species is shown in Figs 18–19 .

Distribution. Thailand: Chiang Mai Province ( Fig. 20 ).

Figures

Figs 1–17. Habitus images of Selasia species. 1 – Selasia dembickyi sp. nov., dorsal view; 2 – S. dembickyi sp. nov., lateral view. 3 – S. jenisi sp. nov., dorsal view; 4 – S. jenisi sp. nov., lateral view. 5–6 – antenna (5 – S. dembickyi sp. nov.; 6 – S. jenisi sp. nov.). 7–8 – pronotum (7 – S. dembickyi sp. nov.; 8 – S. jenisi sp. nov.). 9–13 – Selasia dembickyi sp. nov.: 9 – abdominal sternite IX; 10 – abdominal tergite IX; 11 – abdominal tergite X; 12 – aedeagus, dorsal view; 13 – aedeagus, lateral view. 14–17 – Selasia jenisi sp. nov.: 14 – abdominal sternite IX; 15 – abdominal tergites IX–X; 16 – aedeagus, dorsal view; 17 – aedeagus, lateral view. Scale bars = 2.0 mm (Figs 1–4), 0.5 mm (Figs 5–9, 14–15), 0.2 mm (Figs 10–13, 16–17).

Figs 18–19. Habitat of Selasia dembickyi sp. nov. in Pha Hom Pok Mt. in northern Thailand. Photos: L. Dembický.

Fig. 20. The distribution of Selasia species in the southern part of Asia. Selasia decipiens Guérin-Menéville, 1843 is not included in the map because its exact distribution in India is not known.