Thysanarthria madurensis Hebauer, 2001

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 : 244-246

Thysanarthria madurensis Hebauer, 2001

( Figs 8 K–O, 11 )

Thysanarthria madurensis Hebauer, 2001: 398 .

Type material examined. HOLOTYPE: ♂ ( MZLU), SRI LANKA: ʻCeylon, E. Prov. / Madura Oya / 15 mls NNW Bibile / 13.III.62 Loc. 138 // near river // Lund University / Ceylon Expedition 1962 / Brinck-Andersson- / Cederholm // MZLU / Type no. / 3121:1 // Photo 2017 / by MZLU // MZLU / 2017 / 466’.

Additional material examined. INDIA: KERALA: 1 ♂ ( NHMW): Shoranur, bank of Ponnani river, 31.i.1994, lgt. Z. Kejval. NEPAL: 1 ♂, 2 spec. ( SMNS, NMPC): Narayani, Sauraha, Rapti River bank, light trap, 18.iv.2000, lgt. A. Weigel.

Redescription. Body length 1.3 mm, maximum body width 0.9 mm. Head and labrum black; pronotum uniformly yellowish; elytra uniformly yellowish; legs yellowish. Head with weak granulate microsculpture on interstices; punctation sparse, each puncture bearing pointed seta. Eyes separated by 4.0× the width of one eye in dorsal view. Pronotum with sparse setiferous punctation similar to that on head; interstices with weak granulate microsculpture. Elytra with 10 striae sharply impressed except anteromedially (near 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 8 K–O) 0.4 mm long. Phallobase moderately wide at base of parameres, c. as wide as paramares combined, gradually narrowing towards basal fifth, base abruptly widened, arcuate in lateral view. Parameres narrow and elongate, gradually narrowing towards a pointed apex, apices slightly divergent, outer face of parameres arcuate. Median lobe narrow, not reaching apex of parameres, with a pair of pointed lobes subapically, apex cut off between these projections; gonopore transversely oval, subapical.

Differential diagnosis. In the tiny body size, dorsal surface without microsculpture and narrowly elongate pointed parameres, T. madurensis only resembles T. hongsonensis . See under the latter species for diagnostic charactares.

Biology. Unknown, the Nepalese specimens were collected at light.

Distribution. The species is known from three very distant localities ( Sri Lanka, southern India and Nepal). If the label data especially of the Nepalese specimens are correct, the species is likely widely distributed in the Indian peninsula, but overlooked.

Figures

Fig. 8. Male genitalia of Thysanarthria species, holotypes.A–E – T. chui 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. hongsonensis 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). K–O – T. madurensis Hebauer, 2001 (K–M – whole aedeagus in dorsal, lateral and ventral view; N–O – details of median lobe and parameres 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.