Hydrochus metallipes Knisch

Perkins, Philip D., 2019, Type designations for Neotropical water beetles in the genus Hydrochus Leach 1817 (Coleoptera: Hydrochidae), Zootaxa 4701 (2), pp. 149-167 : 156-157

Hydrochus metallipes Knisch

Figs. 6 , 13A

Hydrochous metallipes Knisch 1920: 56 .

The RBINS kindly provided eighteen syntypes of Hydrochus metallipes Knisch , which are part of the Orchymont/ Knisch types collection. The syntypes consist of both males and females. I have selected one of the males, a specimen in good condition, to serve as lectotype, have labeled it such, and have imaged the habitus, male genitalia and labels of this specimen ( Figs. 6 , 13A ). The seventeen non-lectotype syntypes have been labeled as paralectotypes. Lectotype labels ( Fig. 13A ): “Bras.Corumba [Matto Grosso] // det. Kniž metallipes m. // Coll. A.Knisch TYPUS // coll. A. d’Orchymont: Hydrochus R.M.H.N.B. 15.962 // TYPE // HABITUS/GENIT. DIGITAL IMAGES captured 2019 P.D. Perkins // [red] LECTOTYPE Hydrochus metallipes Knisch desig. P. D. Perkins // Hydrochus tarsalis Chevrolat, 1863 , det. P. D. Perkins, 2019.” The male genitalia of the lectotype of Hydrochus metallipes Knisch 1920 does not differ significantly from the male genitalia of the neotype of Hydrochus tarsalis Chevrolat 1863 . H. metallipes is therefore reduced to status of junior synonym of H. tarsalis Chevrolat.

Remarks. Oliva (1992) published a drawing of the male genitalia of, supposedly, H. metallipes . The parameres are depicted as having a more pronounced enlargement of the medial margin than is present in the lectotype, or in all specimens of H. tarsalis for which the male genitalia have been examined. Oliva (1992) did not give the locality data of the specimen that was used to make the drawing.

Figures

FIGURE 6. Hydrochus metallipes Knisch, habitus and male genitalia of lectotype.

FIGURES 13A–E. Labels of lectotypes and neotype. (A) Hydrochus metallipes Knisch; (B) Hydrochus pumilio Knisch; (C) Hydrochus purpureus Knisch; (D) Hydrochus tarsalis Chevrolat; (E) Hydrochus secretus Knisch.