Hydrochus tarsalis Chevrolat

Perkins, Philip D., 2019, Type designations for Neotropical water beetles in the genus Hydrochus Leach 1817 (Coleoptera: Hydrochidae), Zootaxa 4701 (2), pp. 149-167 : 160-161

Hydrochus tarsalis Chevrolat

Figs. 10 , 13D

Hydrochus tarsalis Chevrolat 1863: 207 .

Hydrochus metallipes Knisch 1920: 56 ; new synonymy.

Hydrochus tarsalis Chevrolat was described based on a single specimen from Cuba (“ Cuba. D. F. Poëy. Unique – collection de l’auteur”). In 2019, Antoine Mantilleri (MNHN), very kindly did a comprehensive search for the type specimen in the Chevrolat and Bedel collections, and was unable to find it. To establish taxonomic stability regarding this species, a specimen from Cuba, collected by P. J. Darlington, is selected to serve as neotype, and has been labeled such. This specimen is deposited in the MCZ collection. The habitus, male genitalia and pin labels of this specimen have been imaged ( Figs. 10 , 13D ). Neotype labels ( Fig. 13D ): “Soledad, Cuba (Cienfuegos) June 1929 Darlington // Hydrochus tarsalis Chevr. Det.J.L.Hellman // HABITUS/GENIT. DIGITAL IMAGES captured 2019 P.D. Perkins // [red] NEOTYPE Hydrochus tarsalis Chevrolat desig. P. D. Perkins. ”

Remarks. Hydrochus tarsalis is a large species. Chevrolat (1863) gives the size of the unique type as “long. 4 ½ mill., lat. 1 3/4 mill.” There is only one currently known species of Hydrochus in Cuba that is this large. The external characters, and the male genitalia, of the lectotype of H. metallipes Knisch do not differ significantly from those of the neotype of H. tarsalis . Hydrochus metallipes is therefore hereby placed as a junior synonym.

Figures

FIGURE 10. Hydrochus tarsalis Chevrolat, habitus and male genitalia of neotype.

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.