Grouvellinus ligulaceus, 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 : 260-262

Grouvellinus ligulaceus sp. nov.

( Figs 2A–B , 7A–C , 14 A–C )

Type materials examined: holotype, male ( IAECAS): “ China: Yunnan (27) / Nujiang Pref. / Lushui City / Pianma Nat. Res. ǀ 25° 59°39′ N 98°39′48″E / 2470 m / 2019.7.6 / Leg. Peng, Dong & Zhu” . Paratypes: 1 male ( IAECAS): “ China: Yunnan (10) / Tengchong City ǀ 25° 43°45′ N 98°34′20″E, 1972 m, 2019.6.30 / Leg. Peng, Dong & Zhu” ; 5 males, 10 females ( IAECAS): “ China: YunnAn / Tengchong City , / Jietou Vill. ǀ 25°31.23′ N 98°33.82′E, / 1910 m, 30.V. 2019 / Leg. Peng et al. (14).”

Diagnosis. Body elongated obovate, with metallic luster; median carina on pronotum absent, sublateral carinae present in basal 0.3, not developed; setiferous punctures on elytral intervals 1, 3, 5 more developed; prosternal process broad, slightly narrowed in basal half, subparallel in distal half, apex somewhat truncate. This species is similar to Grovellinus sinensis (Grouvelle, 1906) in habitus, but it can be distinctly recognized from the latter by its body with metallic luster, and penis ligulate, gradually narrowed in basal 0.8, then distinctly narrowed in distal 0.2, apex broadly rounded, not distinctly sharpened from base to the apex as in G. sinensis .

Description. BL 2.4 mm, BW 1.1 mm. Habitus see Figs 2A–B . Body elongated obovate. Body light brown, with metallic luster, antennae yellowish, ventral side brown to dark brown. Femora and tibiae dark and tarsi light brown.

Head. Labrum micro-reticulate without punctures and pubescence in posterior half, sparsely punctate in anterior half, with a group of long yellowish setae anterior-laterally. Clypeus and frons smooth and shining, setiferous punctures densely distributed.

Pronotum ( Fig. 7A ), PL 0.7 mm, PW 0.8 mm, broadest at basal 0.4, slightly attenuated anteriorly and posteriorly. Median carina absent, sublateral carina not developed, present in basal 0.3, an oblique shallow groove present from apex of sublateral carina to anterior angle on each side. Surface densely covered with setiferous punctures. A pair of small and deep punctures in front of anterior angles of scutellum.

EL 1.7 mm, EW 1.1 mm, subparallel in basal 2/3, then distinctly attenuated in posterior distal 1/3. Strial punctures moderately large, separated by 1–1.5 times of their diameters in basal half. Punctures becoming smaller and well separated in distal half, about 4–5 times of their diameters. Intervals smooth and shining, flat, with a row of setiferous punctures which more developed on intervals 1, 3, 5. Intervals 7, 8 carinate.

Prosternal processs ( Fig. 7B ) slightly narrowed in basal half, and parallel in distal half, lateral margin slightly rimmed; middle disc slightly elevated, smooth and shining, only with few fine punctures, apex broad, somewhat truncate. Metaventrite ( Fig. 7C ) broadly and slightly impressed in posterior 0.8, disc smooth and shining, with setiferous punctures sparsely distributed; lateral area densely pubescent. A row of middle-sized punctures along anterior and posterior margin laterally.

Disc of ventrites I–IV smooth and shining, setiferous punctures sparsely distributed, lateral area densely pubescent. Disc of ventrite V smooth and shining in basal half, only with few fine punctures, the other area of ventrite V densely granulate and pubescent ( Fig. 7C ).

Aedeagus ( Figs 14A–C ). 0.7 mm long. Penis is about 2.4 times as long as phallobase. Penis is ligulate, gradually narrowed in basal 0.8, then distinctly narrowed in distal 0.2, apex broadly rounded. Penis slightly overreaching the parameres. Parameres in ventral view are broad in basal 0.25, then distinctly narrowed to basal 0.5, almost with the same breadth from basal 0.5 to basal 0.9, slightly narrowed in distal 0.1.

Males: BL 2.3–2.4 mm, BW 1.0– 1.1 mm (n=6); females: BW 2.3–2.5 mm; 1.0– 1.15 mm (n=5).

Distribution. China: Yunnan.

Etymology. The epithet is derived from the Latin adjective “ligulaceus” and refers to the distal shape of penis.

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 7. Grouvellinus ligulaceus 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.