Crenitis (Crenitis) obovata, Jia, Fenglong, Tang, Yudan & Minoshima, Yûsuke N., 2016

Jia, Fenglong, Tang, Yudan & Minoshima, Yûsuke N., 2016, Description of three new species of Crenitis Bedel from China, with additional faunistic records for the genus (Coleoptera: Hydrophilidae: Chaetarthriinae), Zootaxa 4208 (6), pp. 561-576 : 565-567

Crenitis (Crenitis) obovata sp. nov.

( Figs. 18–23 )

Type material: Holotype: CHINA : Guangxi: male ( EUMJ), Tieshan Ping / Mt.Miao’er Shan / Guangxi, China / 23-V-1996 / M.Sato leg. // Collection / of Ent. Lab. / Ehime Univ. Paratypes (30 specs., EUMJ, KMNH, NMW, SUSU): CHINA : Guangxi: 1 spec., same data as holotype; 2 males, Tieshan Ping , 2000m / Mt. Miao’er Shan / Guangxi, China / 22-27.V.1996, M.Satô // Collection / of Ent. Lab. / Ehime Univ . Guizhou: 21 specs., CHINA : Guizhou, Leishan Co. / SE Kaili, NE Leishan / Leigong Shan, E - slope / 26°23.39′N 108°13.33′E // 2.5 km E of pass / 19.6.2001, ca . 1600 m / leg. Schillhammer (14); 5 specs., CHINA: Guizhou, Leishan Co. / SE Kaili, NE Leishan / Leigong Shan, E - slope / 26°22.56′N 108°13.40′E // ca . 300 m S of pass / 14.6.2001, ca. 1700 m / leg.

Schillhammer / & Wang ( CWBS 433 ); 1 female, CHINA: Guizhou, Leishan Co. / SE Kaili, NE Leishan / Leigong Shan, E - slope / 1700-1800 m, 14.- 24.6.2001 // env. of pass between / Leishan and Fangxiang / (26°22.74′N 108°12.99′E) / leg. Schillhammer (7).

Diagnosis. Body obovate. Head and pronotum without impression and microsculpture ( Fig. 21 ). Anterior margin of labrum bearing a transverse row of setae. Pronotal punctures uneven, denser laterally than mesally. Ground punctures on elytra rather fine; ten rows of large punctures present on posterior half of elytra ( Fig. 18 ). Mesoventrite flat. Meso- and metafemora pubescent on basal four-fifths ( Fig. 19 ). Parameres with lateral incisions subbasally and subapically, widening in midlength, apex weakly projecting laterally. Apex of median lobe situated ca. apical fourth of parameres in length ( Fig. 23 ).

This species is very similar to C. aduncata and C. lianggeqiui . Ground punctures on elytra of the species are generally finer than C. lianggeqiui (those of C. aduncata are almost same as C. obovata ); reliable identification requires a careful examination of male genitalia. Genital morphology is similar to that of C. lianggeqiui : apex of median lobe is situated in apical fourth ( Fig. 23 ), whereas that of C. lianggeqiui is situated subapically ( Fig. 51 ).

Description. Length 3.6–3.9 mm, width 2.1–2.3 mm. Body obovate, attenuating posteriorly, convex ( Fig. 18 ). Color. Dorsal surface black to dark reddish brown, pronotum somewhat reddish brown, lateral margins of pronotum yellowish brown ( Fig. 18 ). Maxillary and labial palps and antennae uniformly yellowish brown, with infuscate antennal club. Ventral surface dark reddish brown ( Fig. 19 ).

Head. Labrum densely punctate, with broadly emarginate anterior margin; anterior margin of labrum bearing a row of setae densely distributed. Clypeus truncate anteriorly, with dense punctures coarser than those on labrum. Frontoclypeal suture indistinct. Punctures slightly denser on frons than on clypeus. Eyes slightly protruding. Mentum transverse, without impression, with fine punctures, shagreened, without impression; anterior margin of mentum as wide as posterior margin, truncate. Labial palpomere 3 asymmetrical, as long as palpomere 2. Maxillary palpomere 4 asymmetrical, ca. 2 × as long as palpomere 3. Antenna with nine antennomeres, club shorter than antennomeres 1 to 6 combined. Gula narrow, subparallel, gular suture slightly curved medially.

Thorax. Pronotum ( Fig. 21 ) evenly convex, without impressions and systematic punctures; ground punctures on pronotum sparser than those on frons mesally, denser and coarser laterally than mesally; intervals smooth, microsculpture absent ( Figs. 18, 21 ). Lateral and anterior margins of pronotum weakly beaded, anterior margin bisinuate, posterior margin weakly bisinuate, lateral margin evenly curved. Elytra attenuating posteriorly, systematic punctures absent. Ground punctures on elytra rather fine; ten rows of large serial punctures present on posterior half ( Fig. 18 ), lateral three rows strongly impressed, lateral two rows reaching anterior quarter ( Fig. 20 ). Sutural stria almost reaching anterior quarter, deeply impressed ( Fig. 18 ). Prosternum flat, anterior margin broadly protruding. Mesoventrite flat ( Fig. 22 ). Metaventrite covered with pubescence, bulging medially, with a small glabrous area ( Fig. 19 ). Meso- and metafemoral pubescence on basal three-fourths ( Fig. 19 ).

Abdomen. Abdominal ventrites ( Fig. 19 ) densely pubescent. First ventrite not carinate. Apical margin of fifth rounded. Aedeagus. Paramere ( Fig. 23 ) with lateral incision basally and then inflated apical to incision, and then narrowing towards apex; apex projecting laterally. Median lobe oblong arrowhead-like shape; apex of median lobe situated in ca. apical fourth of parameres; manubrium long, apex weakly rounded.

Etymology. Obovata (Latin, adjective, feminine) means obovate, referring to the body shape.

Biology. According to the label data of the paratypes, the specimens were found in aquatic habitats. Paratypes from Sichuan Province were collected in a ‘spring-fed swamp’; a series from Guizhou Province, collected in CWBS (China water beetles survey) loc. 433, were found in a ‘small steep rivulet, in very dark and narrow gorge with dense vegetation’ (after Jäch & Ji, 2003: 8).

Distribution. China (Guangxi, Guizhou).

Figures

FIGURES 18 – 23. Crenitis obovata sp. nov. 18 – 21: Habitus (18: dorsal view, 19: ventral view, 20: lateral view, 21: anterior view); 22: mesoventrite, ventral view; 23: aedeagus, dorsal view. 18 – 20, 22 – 23: Holotype.

FIGURES 50 – 55. Aedeagi, dorsal view. 50: Crenitis aduncata sp. nov.; 51: C. lianggeqiui sp. nov.; 52: Crenitis sp.; 53 – 54: C. convexa Ji et Komarek (53: from Chongqing, 54: from Ningxia); 55: C. apicalis (Reitter).