Thysanarthria saurahana, Fikáček & Liu, 2019

Fikáček, Martin & Liu, Hsing-Che, 2019, A review of Thysanarthria with description of seven new species and comments on its relationship to Chaetarthria (Hydrophilidae: Chaetarthriini), Acta Entomologica Musei Nationalis Pragae 59 (1), pp. 229-252 : 246-247

Thysanarthria saurahana sp. nov.

( Figs 9 A–E, 11 )

Type material. HOLOTYPE: ♂ ( SMNS): NEPAL: ʻNepal, Narayani, Sauraha, Rapti River bank , light trap, 180, 84.49695, 27.56667, 2000- 04-18, A. Weigel, NEPAL, Prov. Narayani / Sauraha, Rapti River / Ufer, 180mNN, 27°34´80´´N, 84°29´49´´E / LF, 18.IV.2000 / leg. Weigel // Thysanarthria / madurensis / det. F. Hebauer’.

Description. Body length 1.7 mm, maximum body width 1.0 mm. Head and labrum black; uniformly yellowish; elytra uniformly yellowish; legs yellowish. Head with strong mesh-like microsculpture on interstices; punctation sparse, each puncture bearing pointed seta. Eyes separated by 2.7× the width of one eye in dorsal view. Pronotum with sparse setiferous punctation similar to that on head; interstices with strong mesh-like microsculpture. Elytra with 10 striae sharply impressed except anteromedially (widely around scutellar shield) where neither striae nor serial punctures are visible; intervals weakly convex at midlength and near apex; interval punctation sparse, setiferous; interstices without microsculpture. Aedeagus ( Figs 9 A–E) 0.5 mm long. Phallobase slightly widened at base of parameres, c. as wide as parameres combined, slightly narrowed towards basal fifth and abruptly widened at base; arcuate in lateral view. Paramere narrowly elongate, subequal in width throughout, apex abruptly narrowing into a short mesoapical ʻtooth’. Median lobe much shorter than parameres, with strongly sclerotized shorter part arcuate apically, and membranous apical part rounded apically; gonopore large, triangular, situated subapically.

Differential diagnosis. Thysanarthria saurahana is the only species in Himalaya with strong mesh-like microsculpture on the pronotum (in contrast to pronotum without microsculpture in T. championi and T. siamensis , and with weak granulate microsculpture in T. madurensis ). It can be distinguished from all these species as well as from all other Thysanarthria by the shape of parameres and the unique morphology of the median lobe which is not similar to any other species of the genus.

Etymology. The species name refers to the village of Sauraha at the border of the Chitwan National Park in Nepal where the holotype was collected. Adjective.

Biology. Unknown.

Distribution. Only known from the type locality.

Figures

Fig. 9. Male genitalia of Thysanarthria species, holotypes. A–E – T. saurahana sp. nov. (A–C – whole aedeagus in dorsal, lateral and ventral view; D–E – detail of median lobe and parameres in dorsal and ventral view). F–J – T. siamensis Hebauer, 2001 (F–H – whole aedeagus in dorsal, lateral and ventral view; I–J – details of parameres and median lobe in dorsal and ventral view).

Fig. 11. Distribution of Thysanarthria and American Chaetarthria in Asia (A–B) and Near East (C), and examples of habitats of Thysanarthria (D–F). Localities: D – India, Madhya Pradesh, Bhadhua Chora stream ca. 10 km E of Matkuli Jhir, habitat of T. ceylonensis Hebauer, 2001; E – Republic of South Africa, Western Cape, 8 km NEE of Stanford, habitat of T. atriceps (Régimber, 1903), collecting spot marked by an arrow; F–G – Taiwan, Wufeng distr., 4.3 km SEE of Chaoyang University of Technology, habitat of T. chui sp. nov. (G – detail of sandy shore with one alive beetle). Photo D by M. Jäch, photo E by M. Fikáček, F–G by H.-C. Liu.