Hydrochus leei, Perkins, 2019

Perkins, Philip D., 2019, Taxonomy of Venezuelan water beetles in the genus Hydrochus Leach, 1817, and an analysis of male genitalia morphology (Coleoptera: Hydrochidae), Zootaxa 4708 (1), pp. 1-59 : 50-52

Hydrochus leei new species

Figs. 1 , 28

Type Material. Holotype (male): “Venezuela: Barinas State: 70° 23.867’ W, 8° 16.954’ N, 70° 23.867’ W, 149m, Ciudad Bolivia, 25.i.2012, leg. Short, Arias & Gustafson; Muddy creek ; VZ12-0125-01A” ( MIZA) . Paratypes (261): Venezuela: Anzoategui: VZ10-0204-01A (2 SEMC) . Apure: VZ09-0118- 02X (3 SEMC) ; VZ09-0118 - 03X (17 SEMC) ; VZ09-0118 - 04X (1 SEMC) . Barinas: Same data as holotype (54 SEMC) ; VZ09-0714 - 05 A (2 SEMC) ; VZ12-0125 - 02 A (8 SEMC) ; Barrancas Research Sta., Rio Yuca , 1 II 1978, 400 ft, seasonal forest, black light, J. B. Heppner (4 NMNH) ; Rio Caparo Res. Station , 32km E El Canton, b-light, 3-5 II 1978, seasonal forest, J. B. Heppner (4 NMNH) . Cojedes: VZ12-0120-03A (1 SEMC) , VZ12-0121 - 03 A (1 SEMC) . Delta Amacuro: VZ10-0203- 01A (2 SEMC) , VZ10-0203 - 02 A (8 SEMC) . Guarico: Calabozo (44 km S), Hato Masaguaral , 4 Mar 1986, PJSpangler, colln#22, large lake (73 NMNH) ; Corozo Pando , (8kmN. NMNH) , 20–21 June 1984, blacklight, F. W. Eiland & V. Linares (1 NMNH) ; Calabozo (44 km S), Hato Masaguaral , 6 Mar 1986, stock tank, PJSpangler, colln#29 (1 NMNH) ; Calabozo (44 km S), Hato Masaguaral , 6 Mar 1986, PJSpangler, colln#30 (2 NMNH) ; Calabozo (44 km S), Hato Masaguaral , 5 Mar 1986, PJSpangler, colln#24 (4 NMNH) ; Calabozo (44 km S), Hato Masaguaral , 4 Mar 1986, large lake, PJSpangler, colln#22 (9 NMNH) ; Calabozo (44 km S), Hato Masaguaral , 6 Mar 1986, gate lagoon, PJSpangler, colln#28 (4 NMNH) ; Corozo Pando , II-12-1969, P. & P. Spangler (1 NMNH) ; San Fernando , II-12- 1969, P. & P. Spangler (26 NMNH) ; Calabozo (44 km S), Hato Masaguaral , 6 Mar 1986, PJSpangler & SBeaujon, colln#31 (23 NMNH) ; 32 km SW. Calabozo II-11-1969, P. & P. Spangler (5 NMNH) . Monagas: VZ10-0719-01A (1 SEMC) . Yaracuy: La Hoya, 100m, 28-30-VI-1973, en la luz, F. Fernandez, Y. J. Salcedo, J. Clavijo (4 SEMC) . Zulia: VZ12-0127-01A (1 SEMC) .

Differential Diagnosis. Among Venezuelan species, recognized by the combination of small size (ca. 1.92–2.31 mm), the dorsum bright silver metallic, the pronotum with shallow depressions with moderately dense punctation, the pronotal shape, the small black spots on the elytra, and the male genitalia ( Fig. 28 ; described below). Differentiation from other similarly small sized species with similarly shaped pronotum will require dissection of males.

Description. Habitus as illustrated ( Fig. 28 ). Size: holotype (length/width, mm): body (length to elytral apices) 1.97/0.76; head width 0.53; pronotum l/w 0.45/0.50; PA 0.50; PB 0.42; elytra 1.18/0.76. Body size small (ca. 1.92–2.31 mm). Dorsum bright silver metallic, with slight bluish iridescence, elytra with several small black spots. Legs testaceous, with tibiofemoral joints darker. Punctation on elytra ca. 2– 3x that of pronotum. Elytra interstriae ca. 0.5– 1x strial puncture diameter. Interstria 9 th more convex than others, overhanging 10 th interstria. Usual area of callus on 5 th not raised.

Pronotum slightly wider than long (as ca. 45/50), widest at anterior margin, markedly narrowed at base, sides very slightly sinuate, smooth; anterior margin weakly bisinuate; depressions moderately shallow, with punctation denser than that of low reliefs.

Elytra with spaces between strial punctures narrow ridges to ca. 0.5x their diameter; apices rather sharply conjointly rounded in dorsal view, in lateral view outer margin with very slight angulation.

Ventral characters: Mentum moderately coarsely and moderately densely punctate, with shallow median fovea. Submentum with two small shallow foveae.

Male genitalia ( Fig. 28 ) general characters: genitalia very small; parameres extending well beyond distal end of aedeagus, tips in dorsal/ventral views wide in proximal part, narrowing apically, with medial margins parallel, in lateral view tips arcuate slightly toward ventrad, and markedly narrowing apically; basal piece long, longer than parameres, tapering from distal end to base, slightly constricted just before orifice, in lateral view slightly arcuate, orifice with rim weakly sclerotized and characteristically shaped; aedeagus narrow, narrowing slightly from base to apex.

Dorsal surface: adtl lacking; pdmm distinctively sclerotized in distal ½, sclerotized area becoming wider from apex until terminating abruptly slightly before midlength of paramere, from which point pdmm becoming narrowly separated and overlapping alm; adbl moderately long.

Ventral surface: pvmm more widely separated than pdmm, contiguous with or nearly so alm.

Etymology. This new species is named for John Leroy Hellman, known as Lee by his friends, in recognition of the hundreds upon hundreds of Hydrochus specimens he carefully mounted and labeled, and the many, many males that he skillfully dissected.

Figures

FIGURE 1. Dorsal habitus of Hydrochus species.

FIGURE 28. Hydrochus leei n. sp., habitus and male genitalia of holotype.