Pelthydrus longifolius, 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 : 61-62

Pelthydrus longifolius sp. nov.

( Fig. 4 )

Type material. Holotype (IAECAS) male: “ CHINA: Hunan, Yueyang City/ Pingjiang County, ca. 290 m / 20. III. 2003, leg. Schönmann/ Komarek & Wang ( CWBS 502)”. Paratypes: 9 exs. (IAECAS), the same data as holotype; 1 ex. (IAECAS), CHINA: Jiangxi, Yicun Prefecture ( CWBS 305); 1 ex. (IAECAS), CHINA: Jiangxi, Yicun Prefecture ( CWBS 306); 1 ex. (IAECAS), CHINA: Hunan, Yueyang City ( CWBS 503); 2 exs. (IAECAS), CHINA: Hunan, Liuyang City ( CWBS 519); 2 exs. (IAECAS), CHINA: Hunan, Liuyang City ( CWBS 521); 1 ex. ( NMW), CHINA: SW Hunan, SW Huitong ( CWBS 30); 14 exs. ( NMW), CHINA: SW Hunan NE Huitong ( CWBS 32); 2 ex. ( NMW), CHINA: SW Hunan, SW Huitong ( CWBS 35); 6 exs. ( NMW), CHINA: Guizhou, Leishan ( CWBS 431); 6 exs. ( NMW), CHINA: Hunan, ca. 25 km N Pingjiang City ( CWBS 498); 12 exs. ( NMW), CHINA: Hunan, NE Nanjianggiao, Mufu Shan ( CWBS 503); 6 exs. ( NMW), CHINA: Hunan, NE Nanjianggiao, Mufu Shan ( CWBS 504); 12 exs. ( NMW), CHINA: Hunan, Dawei Shan ( CWBS 518); 11 exs. ( NMW), CHINA: Hunan, Dawei Shan Nat. Park ( CWBS 519); 3 exs. ( NMW), CHINA: Jiangxi, W Jinggang Shan ( CWBS 302); 7 exs. ( NMW), CHINA: Jiangxi, Jiuling Shan ( CWBS 302); 31 exs. ( NMW), CHINA: Jiangxi, Jiuling Shan ( CWBS 303); 16 exs. ( NMW), CHINA: Jiangxi, Jiuling Shan ( CWBS 304); 8 exs. ( NMW), CHINA: Jiangxi, Jiuling Shan ( CWBS 305); 32 exs. ( NMW), CHINA: Jiangxi, Jiuling Shan ( CWBS 306); 4 exs. ( NMW), CHINA: Jiangxi ( CWBS 506); 3 exs. ( NMW), CHINA: Jiangxi ( CWBS 514); 7 exs. ( NMW), CHINA: Fujian, Chong’an ( CWBS 240); 2 exs. ( NMW), CHINA: Fujian, Chong’an ( CWBS 249); 1 ex. ( NMW), CHINA: Fujian, Chong’an ( CWBS 250); 21 exs. ( NMW), CHINA: Fujian, Chong’an ( CWBS 251); 3 exs. ( NMW), CHINA: Fujian, Yong’an ( CWBS 253); 4 ex. ( NMW), CHINA: Fujian Yong’an ( CWBS 256); 14 exs. ( NMW), CHINA: Fujian, Yong’an ( CWBS 258); 32 exs. ( NMW), CHINA: Fujian, Longyan ( CWBS 260); 23 exs. ( NMW), CHINA: Fujian, Longyan ( CWBS 262); 14 exs. ( NMW), CHINA: Fujian ( CWBS 263); 21 exs. ( NMW), CHINA: Fujian ( CWBS 263); 37 exs. ( NMW), CHINA: Fujian ( CWBS 264).

Diagnosis. This species can be easily identified from the other species in Pelthydrus jendeki group by its much longer median lobe and parameres.

Description. Body length 3.1–3.4 mm; width 2.1–2.3 mm; strongly convex, broadly oval and acute at posterior end, dark brown to black, upper surface shining, maxillary palpi, lateral margins of clypeus, pronotum and elytra as well as legs reddish brown, antennae yellowish brown.

Head trapezoidal, about 2.1 times wider than long, narrower than pronotum; medium-sized punctures sparsely distributed; along the inner sides of the eyes distinctly wrinkled, clypeal suture indistinctly impressed; anterior margin of clypeus concave, anterior corners not angulated; maxillary palpi distinctly longer than antennae.

Pronotum trapezoidal, about 2.1 times wider than long; anterior margin somewhat concave laterally; posterior corners broadly round and shining; lateral sides of pronotum narrowly ridged; punctures denser than those on head.

Elytra broadest at three-tenths from base, slightly narrowed anteriorly and distinctly acute towards the distal apex; punctures a little smaller than on pronotum; lateral sides ridged, wider than those on pronotum.

Ventral side reddish brown, covered with fine pubescence; mentum shining and somewhat rugulose; prosternum with medio-longitudinal carina; mesosternum strongly elevated, producing a triangular plate; metasternum highly raised, with a short medio-longitudinal carina anteriorly, also with a glabrous area posteriorly; hind margin of fifth ventrite round.

Aedeagus ( Fig. 4 ). 1.36 mm long, slender, outline nearly parallel-shaped; phallobase distinctly shorter than median lobe and parameres; median lobe strongly narrowed from distal third towards base, broadest at distal part, ending with a long and sharpened apex; parameres almost equal at basal two thirds, sharply narrowed at distal third and arched towards inner side.

Distribution. China (Guizhou, Hunan, Jiangxi, & Fujian Provinces).

Etymology. Named in reference to the elongated shape of aedeagus.

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.