Hydrochus elineae Makhan

Perkins, Philip D., 2021, Taxonomy of Central American water beetles in the genus Hydrochus Leach, 1817 (Coleoptera: Hydrochidae), Zootaxa 4974 (3), pp. 459-503 : 475

Hydrochus elineae Makhan

Figs. 2 , 19 , 33

Hydrochus elineae Makhan 1994: 41 .

Originally described from Mexico. New locality data records from Mexico are given below.

Material examined (20): Mexico: Nayarit, 18 mi. N.W. Tepic, 27.xi.1948, leg. H. B. Leech (2 CAS) ; 21 mi. S. Acaponeta , 11.viii.1963, leg. E. L. Sleeper (12 CAS) ; 8.7 mi. E. San Blas , 1.vii.1962, leg. E. Sleeper, R. Anderson, A. Hardy, R. Somerby (1 CAS) ; Acaponeta , 15.viii.1960, leg. E. S. Ross, D. C. Rentz, P. H. Arnaud Jr. (5 CAS) .

Differential diagnosis. Among Central American species, recognized by the combination of large size, the largest species in Mexico (ca. 5.00 mm), the deep pronotal depressions, the relatively small prothorax, and the male genitalia ( Fig. 19 ; described below). The male genitalia are characterized by a big basal piece, a wide aedeagus which, in lateral view, has the dorsal surface concave just distal to the adbl.

Male genitalia ( Fig. 19 ). General characters: paramere tips slender and pointed, extending well beyond aedeagus apex, in lateral view parameres abruptly narrowing at tips, in dorsal/ventral views with medial margins at apex parallel or nearly so, then arcuate away from midline, plsa absent or nearly so; aedeagus in dorsal/ventral views wide, agw slightly distal to midlength, margins in proximal ½ slightly sinuate; dorsal margin in lateral view with deep indentation at ca. basal 1/3, otherwise aedeagus wider; lateral margins of aedeagus sclerotized; basal piece distinctly longer than parameres, widened from distal to proximal, width at widest part wider than width at paramere base.

Dorsal surface: pdmm widely separated distally, very narrowly separated at adbl; adbl moderately large; adtl at about distal 1/5.

Ventral surface: pvmm approximating lateral margin of aedeagus in distal ½, overlapping in proximal 1/2; avtl not apparent.

Remarks. I have examined the holotype, including the male genitalia, of H. elineae (ZMHB) . The specimen imaged ( Fig. 19 ) has this locality data: Nayarit, 21 mi. S. Acaponeta, 11.viii.1963, leg. E. L. Sleeper.

Figures

FIGURE 2. Dorsal habitus of Central American Hydrochus species.

FIGURES 19–20. Habitus and male genitalia of holotypes. 19. Hydrochus elineae Makhan, non-type. 20. Hydrochus bernardi Makhan, holotype.

FIGURES 31–33. Geographical distribution maps.