Grouvellinus robustus, Bian & Jäch, 2019

Bian, Dongju & Jäch, Manfred A., 2019, Revision of the species Grouvellinus Champion, 1923 (Coleoptera: Elmidae) with long median pronotal carina, including descriptions of four new species from China, Zootaxa 4586 (1), pp. 127-140 : 136-137

Grouvellinus robustus sp. nov.

( Figures 3 A–B, 8A–C, 10D–F)

Type material: Holotype male ( IAECAS): “ CHINA: Anhui, Dabie Shan \ 40 km N Yuexi, 5.11.1997 \ env. Gui Xing Di, 800m \ leg. Schönmann ( CWBS 295 )” . Paratypes: 32 exs. ( NMW): same data as holotype; 1 female ( IAECAS): “ CHINA: Anhui, Dabie Shan \ 25km N Yuexi, 9.11.1997 \ env. Shi Guan , 1100m \ leg. M. Wang ( CWBS 301 )”; 1 ex. ( NMW): same label data, but “leg. Ji & Wang” .

Diagnosis. It can be distinguished from the other species by its broadly obovate body, male metaventrite with a pair of admedian carinae and also by the large size of the aedeagus.

Description. BL ca. 2.2–2.4 mm, BW ca. 1.25 mm. Body broadly obovate.

Head black, pronotum dark brown to black, elytra dark brown, ventral surface brown to dark brown. Antennae yellowish brown, legs reddish brown.

Head: Labrum more or smooth and shining, superficially reticulate, sparsely pubescent, with setae anterolaterally. Clypeus similar to frons, coarsely and densely granulate, sparsely pubescent.

Pronotum ( Figure 8A ): PL 0.7 mm, PW 0.9 mm, distinctly convex, broadest at basal 2/5, anteriorly not distinctly attenuate. Surface densely granulate, sparsely pubescent. Sublateral carinae present in basal 2/5, each side with an oblique impression extending from apex of carina towards anterior angles. Median carina well developed, extending from base to basal 0.8.

Elytra: EL 1.65 mm, subparallel from base to basal 2/3, then gradually narrowed to apex. Strial punctures large and rather deeply impressed on disc, separated by 0.5–1.0 times of their diameters. Punctures becoming smaller and shallower in distal half, separated by 2–4 times of their diameters. Intervals 4 and 6 sometimes briefly elevated and granulate near base, forming short carinae. Intervals 3, 5, 7, 8 distinctly carinate, granulate and slightly pubescent. Carina of interval 3 shorter than carinae on intervals 5, 7, 8. Remaining intervals slightly convex, sparsely pubescent.

Prosternal process tongue-like, distinctly rimmed laterally. Disc almost flat, densely granulate and sparsely pubescent; apex broadly rounded. Metaventrite with disc broadly impressed medially; lateral margins of impression carinate, distance between these two carinae approximately as wide as apex of prosternal process. Sublateral area densely granulate and sparsely pubescent; laterally with an oblique row of very large punctures, and with a deep transverse groove at anterior and posterior margin. All ventrites densely granulate throughout, sparsely pubescent.

Male genitalia ( Figure 10 D–F): ca. 0.80 mm long. Penis in ventral view gradually narrowed from base to apex, distinctly longer than phallobase, slightly exceeding parameres; apex broadly rounded; ventral sac weakly developed. Parameres in ventral view broad from base to basal 0.1; mesal margin emarginate from basal 0.1 to basal 0.4; width of parameres almost the same from basal 0.4 to apex, apices narrowly rounded.

Females: Metaventrite without pair of admedian carinae.

Distribution. China (Anhui).

Etymology. The epithet is derived from the Latin adjective “robustus” and refers to the comparatively stout body form.

Figures

FIGURE 3. Habitus. A–B) Grouvellinus robustus, holotype male. A) in dorsal view; B) in ventral view.

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

FIGURE 10. Aedeagus. A–C) Grouvellinus mediocarinatus. D–F) G. robustus. A, D) in ventral view; B, E) in dorsal view; C, F) in lateral view. Scale: 0.2 mm.