Hydraena (Hydraena) puetzi Jaech , 1994

Lee, Dae-Hyun & Ahn, Kee-Jeong, 2016, A taxonomic review of the Hydraenidae in South Korea (Coleoptera), ZooKeys 634, pp. 57-78 : 59-61

Taxon classification Animalia Coleoptera Hydraenidae

Hydraena (Hydraena) puetzi Jaech, 1994 Figs 1, 6-17, 50, 55

Hydraena (s. str.) puetzi Jäch, 1994: 43; Jäch and Skale 2015: 139.

Specimens examined.

SOUTH KOREA: Gangwon Prov.: 1♀, Goseong-gun, Ganseong-eub, Jinburyeong, N38°15'59" E128°23'04", 640m, 21.VII.2004, KM Yang, JS Park, leaf litter; 1♂ 2♀♀,Hongcheon-gun, Nae-myeon, Changchon-ri, Unduryeong-hill, 10.VIII.2012, SW Jeong, mountain stream; 1♂, Hongcheon-gun, Seo-myeon, Bangok-ri, Bangokgyo, 17.IX.2009, DH Lee, mountain stream (1♂, on slide); 1♂ 3♀♀, Pyeongchang-gun, Daegwanryeong-eub, Yucheon-ri, Haewon-temple, 15.IX.2009, YJ Park, under stone on stream margin (1♂, on slide); 1♀, Pyeongchang-gun, Jinbu-myeon, Dongsan-ri, Mt. Odaesan, Sangwon-temple, 16. VIII– 15.IX. 2001, SJ Park, CW Shin, FIT; 1♂, same data as former except for, 8.V.2004, DH Lee, stream; 1♂, same data as former except for, 8.V.2004, DH Lee, stream; 9♂♂ 11♀♀, same data as former except for, Mt. Odaesan, 22.V.2012, DH Lee, springfed pool; 1♂, Samcheok-si, Gagok-stream, 25.VI.1985. SH Lee; 3♀♀, Yeongwol-gun, Suju-myeon, Mt. Baehyang-san, 17.VII.2010, SW Jeong, mountain stream; Gyeongbuk Prov.: 1♀, Uljin-gun, Buk-myeon, Mt. Eungbongsan, 6.VI.1995, SH Lee; 1♂, Uljin-gun, Seo-myeon, Wangpi-ri, Golan-bridge, N36°54'27.1" E129°14'34.2", 385m, 26.IV.2012, DH Lee, mountain stream; Gyeonggi Prov.: 1♀, Gapyeong-gun, Buk-myeon, Jeongmok-ri, Garim-bridge, 16.IX.2010, SW Jeong, stream; 1♂, Paju-si, Jangdan-myeon, Nosang-ri, 21.IX.2012, SW Jeong, stream.

Published South Korean records.

Hydraena puetzi : Jäch and Skale (2015: 103). Hydraena riparia : Kwon and Suh (1986: 99); Kim et al. (1994: 134); Lee (1995: 13); Han et al. (2007: 271); Han et al. (2008: 263); Cho and Park (2010: 96) [misidentification].

Redescription.

Length 2.0-2.3 mm. Head black; pronotum and elytra brown to dark blue; ventral surface dark brown. Head (Fig. 6) trapezoidal, widest cross eyes, ventral side (Fig. 7) with sparse setae. Anterior margin of labrum (Fig. 6) nearly straight except antero-medial part deeply excised. Clypeus (Fig. 6) with relatively small punctures; antero-medial margin broadly rounded; antero-lateral part protruded. Frontoclypeal suture (Fig. 6) bisinuate. Mentum (Fig. 8) subquadrate, widest at posterior corner, with large punctures on anterior and lateral parts; anterior margin broadly rounded, with a row of thick setae; posterior part protruded laterally. Submentum (Fig. 7) semicircular; antero-medial margin nearly straight, dentate; antero-lateral margin protruded and acute. Antenna with nine antennomeres; 1 longest, approx. 2.5 times as long as 2; 2 approx. 6.0 times as long as 3, bulbous at basal part; 3 bulbous at apical part; 4 dish-shaped; 5-9 clubbed and with pubescence. Maxillary palpomere (Fig. 9) 1 smallest; 2 longest, approx. 3.0 times as long as 3, few setae present on ventral part, with transverse imbricate reticulation except apical part; 3 bulbous at apical part, few setae present on dorsal and ventral parts, with imbricate reticulation except anterior third; 4 approx. 2.0 times as long as 3, many setae present on dorsal and ventral parts, apical part acute, with imbricate reticulation except anterior to middle. Pronotum (Fig. 10) hexagonal, widest at middle and narrowest posterior part, medial part protruded and flattened; anterior margin sinuate; antero-median margin straight; anterior and posterior corners rectangular; lateral margin rounded and serrated. Elytra (Figs 11, 12) widest at middle; antero-lateral and postero-lateral parts serrated. Prosternum (Fig. 13) transverse, with longitudinal carina on medial part; anterior and posterior corners acute. Mesoventrite (Fig. 14) reverse pentagonal, with two vertical carina on each side of midline. Mesotibia (Fig. 15) serrate on apico-lateral part, with thick spines. Metaventrite (Fig. 16) flattened, with two glabrous parts medially. Sternite VII (Fig. 17) with many long setae on medial part in female. Male terminal sternite semicircular; postero-medial part bifid; posterior part rounded and with many setae. Median lobe of aedeagus (Fig. 50) longer than paramere, strongly curved at middle; a seta present on anterior third; apical part acute and protruded; flagellum bisinuate. Left paramere (Fig. 50) as long as right; apical part long-oval; many long setae present on apical margin. Apical part of right paramere (Fig. 50) semicircular; many long setae present on apical margin.

Distribution.

Korea, China (Liaoning, Shandong), Russia (Far East).

Biological note.

They are found under leaves or stones in margins of mountain streams. Some specimens were collected from submerged branch and leaves in seepage on small cliff.

Remarks.

Kwon and Suh (1986) first recorded this species as Hydraena riparia in Korea. After that, many entomologists [ Kim et al. (1994); Lee (1995); Han et al. (2007); Han et al. (2008); Cho and Park (2010)] reported the species, only in the local fauna without any taxonomic comments. After studying the specimen (1♂, Samcheok-si, Gagok-stream, 25.VI.1985. SH Lee) previously examined by Kwon and Suh (1986), we found that it had been incorrectly identified and actually is Hydraena puetzi . This species can be distinguished from Hydraena riparia by left paramere (Fig. 7A) parallel at middle, and apical part of right paramere (Fig. 7A) semicircular, with compact long setae on apex.