Tshernyshev, Taskaeva & Kolesnikova & Nakul, 2020

Tshernyshev, S. E., 2020, Intybia (Protolaius), a new subgenus of soft winged flower beetles (Coleoptera: Malachiidae) from Indonesia, Russian Entomological Journal 29 (2), pp. 173-177 : 175

Intybia (Protolaius) Tshernyshev , subgen.n.

Type species: Laius schillhammeri Wittmer, 1996 , designated herewith.

DESCRIPTION. Moderately small-size (c. 3.5 mm) malachiid beetles with slightly elongate sub-oval body, slightly expanded posteriorly ( Figs 1–3 ). Upperside with monochromous colouration of dark-blue metallic lustre, roughly and sparsely puncturation and sparse long dark and erect pubescence of head, pronotum and elytra are typical for the subgenus. Antennae ( Fig. 4 ) filiform, not serrate, thin, almost completely reaching middle of elytra; in male 1 st and 3 rd segments enlarged, scapus clavate, sub-triangularly widened distally, the 3 rd segment oval, slightly flattened, complicatedly impressed, lacking a tuft of hairs. Palpae short, apical segment sub-oval and truncate. Head conjugate with convex anterior part of the pronotum, slightly wider than pronotum, eyes small, round, protruding, disc of the head between eyes slightly depressed. Pronotum transverse, weakly protruding and convex anteriorly, strongly depressed and sinuate to the base just behind the middle, with posterior margin elevate and swollen; sides with thin margins, anterior angle rounded, posterior distinct and almost at a complete right angle.

Elytra sub-oval and elongate ( Figs 1–3 ), slightly expanded posteriorly, coarsely punctured, with short and slightly protruding shoulders; apices evenly rounded, simple. Surface evenly covered with strong, erect sparse black hairs and sparse short light-coloured adpressed pubescence on periphery. Anterior femora in male excavate in the middle and provided with a tuft of light-coloured long straight hairs ( Figs 6–7 ), anterior tarsi simple, lacking comb ( Fig. 5 ). Metathorax slightly swollen, transverse, simple, lacking appendages or tufts of hairs. Apical tergite in male undivided, simple, transversal, narrow, apical sternite bilaciniate, narrow, transverse, aedeagus slightly curved, extremely elongate at apical third, with evenly narrowed and short lamella, two strong long horns in inner sac are noticeable at base of the aedeagus ( Figs 8–11 ).

DIAGNOSIS. Monochromous dark blue metallic coloured beetles of c. 4 mm in length, roughly punctured and densely covered with strong erect black setae. Pronotum strongly sinuate at base and narrower than elytra. Sexual dimorphism is not contrasting, noticeable in 1 st and 3 rd antennomeres and excavate femora in males. From representatives of the nominative subgenus it can be easily separated by the male characters, namely excavate femora and aedeagus with extremely elongate apical part.

ETYMOLOGY. The name of the subgenus reflects similarity with the genus Laius according to the special male character of the anterior femora that can be considered to be an ancestral character of the genus.

NOTES. Two species are included in the subgenus due to typical male femora in anterior legs, I. (P.) schillhammeri and I. (P.) lombokana (Pic, 1910) (= I. jaechi ( Wittmer, 1996)) . The decision is based on study of types of these species, kindly carried out by Isidor S. Plonski. He informed that the photos was compared with the holotype of I. schillhammeri , and are found conspecific. The only difference is in colouration, the third antennomere in holotype is brownish enlightened on the inner side. Furthermore, the excavated femorae in I. schillhammeri and I. lombokana are confirmed. Presumably, Intybia cibrosa (Pic, 1937) could also be included in this subgenus, but the male special characters should be examined first in view of the poor original description of the species.

Figures

Figs 1–11. Intybia (Protolaius) schillhammeri (Wittmer, 1996), male (1–2, 4–11) and female (3). 1, 3 — external appearance, dorsal view; 2 — external appearance, lateral view; 4 — left antenna; 5 –right anterior tarsus; 6 — femur of left anterior leg; 7 — femur of right anterior leg; 8 — apical tergite; 9 — apical sternite; 10 — aedeagus, lateral view; 11 — tegmen. Scale bars: 0.5 mm. Рис. 1–12. Intybia (Protolaius) schillhammeri (Wittmer, 1996), самец (1–2, 4–11) и самка (3). 1–2 — внеШний вид дорЗально; 2 — внеШний вид, сбоку; 4 — левый усик; 5 — праваЯ переднЯЯ лапка; 6 — бедро левой передней ноги; 7 — бедро правой передней ноги; 8 — апикальный тергит; 9 — апикальный стернит; 10 — Эдеагус, латерально; 11 — тегумен. МасШтаб: 0,5 мм.