Pelthydrus rosa, Bian, Dongju, Schönmann, Heinrich & Ji, Lanzhu, 2009

Bian, Dongju, Schönmann, Heinrich & Ji, Lanzhu, 2009, Five new species of Pelthydrus Orchymont, 1919 from China and adjacent countries (Coleoptera: Hydrophilidae), Zootaxa 2118, pp. 53-64 : 62-63

Pelthydrus rosa sp. nov.

( Fig. 5 )

Type material. Holotype (IAECAS) male: “ CHINA: NW-Hunan Province 1993/ Wulingyuan, N Dayong/ Suoxiyu, 31. 10., 450 m / leg. L. Ji (6)”. Paratypes: 16 exs. ( NMW), the same data as holotype.

Diagnosis. This species can be easily identified from the other species in Pelthydrus jendeki group by its robust aedeagus and truncate distal part of parameres at inner sides.

Description. Body length 3.5 mm; body width 2.1 mm. Body strongly broadly convex, oblong-oval, acute at elytral apex; complete surface shining, testaceous–brown to darkish–brown; maxillary palpi, lateral margins of head, pronotum and elytra reddish brown, antennae, labial palpi and tarsi yellowish brown.

Head trapezoidal, about 1.7 times wider than long, distinctly narrower than pronotum; gradually widened towards posterior part; sparsely covered with median–sized punctures appearing wrinkled along lateral margins and innersides of eyes; clypeal suture distinctly impressed; anterior margin of clypeus concave, anterior corners roundly angulated.

Pronotum trapezoidal, about 2.1 times wider than long; lateral margins narrowly ridged; anterior margin somewhat arched at middle; punctures sparsely distributed, larger than those on head; anterior corners angulated, posterior corners broadly rounded and transparent.

Elytra about 1.1 times longer than wide; broadest part at three tenths from base, from there distinctly narrowed posteriorly; punctuation much smaller and sparser than that on head; with ten false striae; anterior half of lateral margin broadly ridged and somewhat upturned.

Ventral side mostly yellowish brown to darkish brown, covered with fine pubescence; mentum somewhat rugulose, shining, and sparsely covered with median-sized punctures; prosternum with a medio-longitudinal carina which progressively elevated; mesosternum elevated posteriorly producing a pentagonal plate, which has a round apical part; metasternum highly raised, middle area darker than lateral part, with a “n”-shaped projection at base, an irregular shaped area glabrous; first ventrite with a medio-longitudinal carina, about one fourth of the total length; hind margin of fifth ventrite round, not emarginate.

Aedeagus ( Fig. 5 ). 1.22 mm long, robust, phallobase distinctly shorter than median lobe; median lobe gradually widened form base, constricted at middle, then almost parallel-sided ending with a sharp apex; parameres gradually narrowed from base towards apex, distal half distinctly narrowed, apices somewhat truncated at innersides.

Distribution. China: Hunan Province.

Etymology. This species is dedicated to Rosa Schönmann. We want to thank her for her hearty way of caring for CWBS guest scientists when staying in Vienna.

Figures

FIGURES 1 – 6: Aedeagus in dorsal view. 1. Pelthydrus grossus sp. nov. (holotype); 2. Pelthydrus grossus sp. nov. (paratype from Laos); 3. Pelthydrus subgrossus sp. nov.; 4. Pelthydrus longifolius sp. nov.; 5. Pelthydrus rosa sp. nov.; 6. Pelthydrus yulinensis sp. nov.