Gyrinus (s. str.) gestroi Regimbart , 1883

Lee, Dae-Hyun & Ahn, Kee-Jeong, 2015, A taxonomic review of the Gyrinidae (Coleoptera) in Korea, ZooKeys 509, pp. 87-107 : 91

Taxon classification Animalia Coleoptera Gyrinidae

Gyrinus (s. str.) gestroi Regimbart, 1883 Figs 2, 18, 23-25, 44-46, 58

Gyrinus gestroi Régimbart, 1883: 165.

Specimens examined.

SOUTH KOREA: Jeju Prov.: 1 ♂, Bukjeju-gun, Jocheon-eub, Gyorae-ri, 10.V.1974; 1 ♂ 1 ♀, same data as former except for, 27.VII.2005, DH Lee, pond; 3 ♂♂ 3 ♀♀, same data as former except for, Seonheul-ri, 11.VI.2005 (1 ♂, on slide); 1 ♂, same data as former except for, 28.VII.2005, SH Lee, (1 ♂, on slide); 2 ♂♂ 1 ♀, same data as former except for, 22.V.2006; 2 ♂♂ 2 ♀♀, same data as former except for, 25.IX.2008; 1 ♂, same data as former except for, 15.VI.2011 (1 ♂, on slide); 2 ♂♂ 2 ♀♀, Jeju-si, Ara-dong, Gwaneum-temple, 22.VII.1990, SH Lee; 1 ♀, same data as former except for, Jeju National University, 11.VII.1985; 1 ♂, Seoguipo-si, Pyoseon-eub, 10.VII.1985; 1 ♀, Seoguipo-si, Seoho-dong, 23.VII.1990, SH Lee, pond; 1 ♂, Seoguipo-si, Seongsan-eub, Ojo-ri, 24.VII.1990, SH Lee.

Published Korean records.

Gyrinus gestroi : Kwon and Suh (1986: 98); Lee et al. (1992: 54); Kim et al. (1994: 134); Lee (1995: 13); Park et al. (2008: 247); Cho and Park (2010: 95).

Diagnosis.

Length 4.5-5.5 mm. Ventral surface mostly black; ventral part of antennomere 2, mouthparts, prosternum, legs, posterior part of sternite VII, sternite VIII yellowish brown to brown; hypomera, epipleura dark brown. Ligula with a row of sparse spines on antero-medial part. Anterior margin of mesoventrite rounded, posterior margin bifid with very deep pit (arrow in Fig. 23), large groove present on postero-medial and antero-lateral parts. Metepisternum with a deep pit (arrow in Fig. 24), oval groove present on anterior part. Sternite II with deep pit (arrow in Fig. 25), transverse groove on anterior part. Median lobe of aedeagus (Figs 44-46) nearly parallel-sided at middle to apex, slightly shorter than paramere; apical margin rounded; sperm-groove as in Fig. 45. Paramere (Figs 44, 46) broader than median lobe; apical margin broadly rounded.

Distribution.

Korea, Japan ( Mazzoldi 2003).

Habitat.

All specimens were collected in ponds with plentiful vegetation in Jeju-do Island. They are frequently found together with Dineutus orientalis or Gyrinus japonicus .