Grouvellinus lubricus, Bian & Zhang, 2023

Bian, Dongju & Zhang, Yi, 2023, Descriptions of eight new species of Grouvellinus from China (Coleoptera, Elmidae), Zootaxa 5254 (2), pp. 257-277 : 262-263

Grouvellinus lubricus sp. nov.

( Figs 2C–D , 8A–C , 14D–F )

Type material examined: holotype, male ( IAECAS): “ China: Yunnan (7) / Dehong Pref. / Yingjiang County / Madao Vill. ļ 25°34′43″N 97°42′57″E / 1438 m, 2019.6.29 / Leg. Peng, Dong & Zhu” . Paratypes: 4 males ( IAECAS): “ China: Yunnan, Dehong / Yingjiang, Tongbiguan / 24°40′6″N 97°35′57″E / 922 m, 2019.6.24 / Leg. Leg. Peng, Zhu & Dong (3)” ; 1 male ( IAECAS): “ China: Yunnan / Yingjiang Pref. / Nabang Town ļ 24°37.38′N 97°37′48″E ” / 1478 m / 26. VI. 2019 / Leg. Peng et al. (6) ; 1 male ( IAECAS): “ China: Yunnan (8) / Dehong Pref. / Yingjiang County / Tongbiguan ļ 24°36′36″N 97°44′0″E / 1522 m / 2019.6.29 / Leg. Peng, Zhu & Dong” ; 1 male, 3 females ( IAECAS): “ China: Yunnan / Nujiang, Lushui / Dashanpingziļ 25°41′6″N 98°50′16″E / 1026 m / 4. VII. 2019 / Leg. Peng et al. (23)” ; 1 male ( NHMW): “ China’ : Yunnan 14.-21.6. / 100 km W Baoshan, 1993 / Gaoligongshan Nat. Res. / E. Jendek & O. Sauss leg.” .

Diagnosis. Body small in size, brown to dark brown; median carina or median sulcus is absent on pronotum, sublateral carinae on pronotum present in basal 0.35, but not developed; elytral intervals flat; prosternal process nearly inverted trapezoid, apex truncate. This species is similar to Grovellinus cruxniger Freitag et al., 2019 in habitus and body size, but it can be distinguished from the latter by its elytra without two pair of extended yellowbrown spots, by penis distinctly extends parameres, and also by parameres slimmer. This species is also similar to Grouvellinus macilentus sp. nov. in outline, but can be distinguished from the latter by pronotum with small granules in front of anterior angles at base, without a pair of impressions in front of anterior angles which present in G. macilentus , and also by aedeagus distinctly larger, distal 0.2 of penis distinctly narrowed, and apex broadly rounded.

Description. BL 1.85 mm, BW 0.9 mm. Habitus see Figs 2C–D . Body elongate, brown to dark brown. Legs, mouth part and antennae yellowish brown.

Head. Labrum smooth and shining, setiferous punctures on lateral margin denser than on disc, with a group of yellowish long setae anterior-laterally. Clypeus and frons smooth and shining, setiferous punctures moderately dense.

Pronotum ( Fig. 8A ) broadest at basal 0.4, PL 0.5 mm, PW 0.65 mm, distinctly attenuated anteriorly and posteriorly. Disc smooth and shining, short setiferous punctures densely punctate, and the area near anterior and posterior angles somewhat rugulose. Median carina absent. Sublateral carinae not developed, present in basal 0.35, bend inwards in distal 1/3, and a groove distinctly extends from the apex of carina towards the anterior angle on each side. Base with some small granules in front of anterior angles of scutellum.

EL 1.3 mm, 0.9 mm. Elytra subparallel in basal half, distinctly attenuated in distal half, strial punctures small and deep in basal half separated by 1.5 to 3.0 times of their diameters. Punctures smaller and shallower in distal half. Intervals flat, smooth and shining. A row of setiferous punctures more developed on intervals 1, 3, 5. Intervals 7, 8 carinate.

Prosternal process ( Fig. 8B ) is nearly inverted trapezoid, gradually narrowed in basal half and subparallel in distal half, lateral margin distinctly rimmed, apex truncate; surface smooth and shining in basal 0.6, coarse in distal 0.4. Metaventrite ( Fig. 8C ) broadly and distinctly impressed in posterior 0.8, surface smooth and shining, with few small setiferous punctures. A row of large punctures behind of mesocoxa and a row of small punctures in front of metacoxa on each side.

Disc of ventrites I–IV smooth and shining, fine setiferous punctures sparsely distributed, lateral area of ventrites I–IV densely pubescent and sparsely granulate. Disc of ventrite V smooth and shining in basal 0.3, the other area rugulose, densely pubescent and granulate. Ventrite I with a pair of ad-median carinae.

Aedeagus ( Figs 14D–F ) 0.6 mm long. Penis is about 2.4 times as long as phallobase. Penis broad, slightly expand at basal 0.3, then slightly narrowed to basal 0.8, distal 0.2 distinctly narrowed, apex broadly rounded. Parameres distinctly shorter than penis, distinctly narrowed from base to the apex.

Males: BL 1.8–1.9 mm, BW 0.9–1.0 mm (n=8); females: BL 1.9 mm, BW 0.9–1.0 mm (n=3).

Distribution. China: Yunnan.

Etymology. The epithet is derived from the Latin adjective “lubricous”, refers to its smooth and shining surface of pronotum and elytra.

Figures

FIGURE 2. Habitus A–B) Grouvellinus ligulaceus sp. nov. C–D) G. lubricus sp. nov. A, C) dorsal view B, D) ventral view.

FIGURE 8. Grouvellinus lubricus sp. nov. A) anterior part of body, dorsal view; B) same, ventral view; C) posterior part of body, ventral view.

FIGURE 14 Aedeagus A–C) Grouvellinus ligulaceus sp. nov. D–F) G. lubricus sp. nov. A, D) ventral view B, E) dorsal view C, F) lateral view.