Helochares (Hydrobaticus) tengchongensis, Dong & Bian, 2021

Dong, Xue & Bian, Dongju, 2021, Three new species and two new records of Helochares (Hydrobaticus) MacLeay 1871 from China (Coleoptera: Hydrophilidae: Acidocerinae), Zootaxa 4950 (1), pp. 166-180 : 171-173

Helochares (Hydrobaticus) tengchongensis sp. n.

( Figs. 9–12 )

Material examined. Holotype (IAECAS): 1 male, “ CHINA: Yunnan Province, Tengchong City, / Lianghe County, Longhe Village , 1074 m, | 24°48′21.158″N, 98°17′51.522″E, / 2016.10.22, leg. Wang, Peng & Sun” . Paratypes (47): (IAECAS): 17 males, 8 females: “ CHINA: Yunnan Province, the road from / Nanleng village, Mangshi to Ruili City , | 839 m, 24°9′37.812″N, 98°6′24.198″E, / 2016.10.16, leg. Wang, Peng & Sun ” ; 6 males, 6 females: “ CHINA: Yunnan Province, the road from / Nanleng village, Mangshi to Ruili City , | 827 m, 24°13’50.83”N, 98°15’51.534”E, / 2016.10.16, leg. Wang, Peng & Sun ” ; 3 males: “ CHINA: Yunnan Province, Ruili City, / Kema Village , 839 m, | 24°3′54.540″N, 97°57′47.813″E, / 2016.10.17, leg. Wang, Peng & Sun ” ; 1 male, 3 females: “ CHINA: Yunnan Province, Mangshi, / Nongkan Village , 780 m, | 24°9′46.692″N, 98°6′5.142″E, / 2016.10.18, leg. Wang, Peng & Sun ” ; 1 female: “ CHINA: Yunnan Province, Tengchong City, / Mingguang Village bridge downstream, 1826 m, | 25°28′39.318″N, 98°31′53.016″E, / 2016.10.23, leg. Wang, Peng & Sun ” ; 1 female: “ CHINA: Yunnan Province, Baoshan City, / Mangkuan Town, Xinguang Village , 1026 m, | 98°50’53”E, 25°28’18”N, / 2018.10.23, leg. Peng, Zhu & Dong ” ; 1 male: “ CHINA: Yunnan Province, Baoshan City, / Mangkuan Town, Mangkuan Village , 847 m, | 98°51’44”E, 25°26’53”N, / 2018.10.23, leg. Peng, Zhu & Dong ” .

Diagnosis. This new species is similar to Helochares lentus in habitus, but can be distinguished by the following characteristics: (1) H. tengchongensis (3.6–4.2 mm) is usually smaller than H. lentus (4.0– 5.5 mm); (2) serial punctures on elytra are smaller, interstrial punctures are denser than in H. lentus ( Fig. 9 ); (3) aedeagus ( Fig. 11 ) broad. Apex of median lobe with a pair of cylindric protuberances. Membranous inner sac with a torch-shaped structure medially ( Fig. 11b ), and strongly sclerotized with some dentate structures ( Fig. 11c ).

Description. Habitus as in Figs. 9–10 . BL: 3.6–4.2 mm, BW: 1.8–2.2 mm. Body oval, moderately convex. Head and elytra dark brown, pronotum brown, apex of tarsal claws black, ventral side dark brown.

Head ( Fig. 9 ). Labrum black, anterior margin straight, with sparse and fine punctures. Clypeus dark brown, broad, densely punctate; anterior margin broadly emarginate; the area in front of eyes moderately expanded laterally, with sparse punctures. Eyes rounded in dorsal view, slightly bulging; somewhat prominent; several setae anteriad to eyes. Frontoclypeal suture distinct, a pair of splayed black marks on frons. Systematic punctures small and distinct. Antennae with nine antennomeres, yellowish-brown; club loosely articulated, with densely pubescences. Maxillary palpi moderately long and slender, about 1.0 times long as the width of head, yellow, second palpomere curved inwards. Mentum and submentum dark brown, with coarse punctures and wrinkles.

Thorax ( Figs. 9–10, 12 ). Maximum width of pronotum about as twice as length; punctures distinct and dense; anterior and posterior angles broadly rounded. Anterior margin slightly projected anteriad in mid-length, with a row of setae, a median black mark near anterior margin. Lateral margin slightly lighter in color. Posterior margin slightly corrugate; posterior area with a pair of small pits which overlap with black marks ( Fig. 9 ). Prosternum ( Fig. 12 ) slightly bulging at the middle, not carinate, protruding posteriorly, rugulose, with fine and dense punctures. Mesoventrite strongly convex posteromedially. Metaventrite pubescent, with fine punctures and somewhat convex at middle portion, with convex part densely pubescent ( Fig. 10 ). Elytra ( Fig. 9 ) together slightly wider than pronotum, widest at middle, then distinctly attenuate posteriorly; elytra with scutellary stria and ten impressed series of punctures, but not striate; interstrial punctures small, serial punctures slightly larger than interstrial punctures; large punctures on underside of elytra usually visible from dorsal view on distal quarter. Elytral suture distinct; scutellum shield triangular, with several fine punctures.

Legs. Femora dark brown, tibiae and tarsi brown, apex of tarsal claws black. Femora densely pubescent with apical fifth glabrous. Tarsi with dense white setae.

Abdomen. All visible ventrites with dense pubescences and fine punctures; apex of ventrite five strongly emarginate.

Aedeagus ( Fig. 11 ). Broad, 1.0 mm long. Basal piece short, about 0.2-times of aedeagus length. Parameres nearly parallel-sided on outer margins, apical third gradually narrowed and apex narrowly rounded. Median lobe longer than parameres, about 4.5 times as long as basal piece, apex with two cylindric protuberances ( Fig. 11a ); apophyses of median lobe extending beyond base of basal piece. Membranous inner sac with a torch-sharped structure medially ( Fig. 11b ), and strongly sclerotized with some dentate structures ( Fig. 11c ).

Distribution. Known only from Yunnan Province, China.

Etymology. Named after the type locality, Tengchong City, Yunnan Province, China.

Habitat ( Fig. 27 ). Slow flowing pool, with mud, deadwood and sides with mossy stones, and fireweed.

Figures

FIGURES 9–12. Helochares (Hydrobaticus) tengchongensis sp. n. 9–10. Habitus. 9. Dorsal view. 10. Ventral view. 11. Aedeagus (a. Cylindric protuberances of median lobe; b. Torch-shaped structure in membranous inner sac; c. Dentate structures). 12. Prosternum.

FIGURES 25–27. Habitat. 25. Wanquan Town, Qionghai City, Hainan Province (Helochares (Hydrobaticus) hainanensis sp. n.); 26. Wuzhifeng Town, Ganzhou City, Jiangxi Province (Helochares (Hydrobaticus) wuzhifengensis sp. n.); 27. Mangkuan Village, Baoshan City, Yunnan Province (Helochares (Hydrobaticus) tengchongensis sp. n.).