Hydraena reverberata, Perkins, Philip D., 2011

Perkins, Philip D., 2011, New records and description of fifty-four new species of aquatic beetles in the genus Hydraena Kugelann from South America (Coleoptera: Hydraenidae), Zootaxa 3074, pp. 1-198 : 34-35

Hydraena reverberata , new species

Figs. 52 (habitus), 54 (aedeagus), 197 (map)

Type Material. Holotype (male): Venezuela : Territorio Federal Amazonas, Puerto Ayacucho (40 km S.), at Tobogan , sandy margins, colln. #10, 23 ii 1986, P. J. Spangler. Deposited in the MIZA. Paratypes (14): Venezuela : Amazonas, just S. of Communidad Porvenir, small streamlet, elev. 87 m, 5° 20.514' N, 67° 45.315' W, 15 i 2009, Short, Miller (VZ09-0115-03B) (2 SEMC); Road between Puerto Ayacucho and Gavilan, small stream, elev. 66 m, 5° 34.408' N, 67° 30.283' W, 6 i 2006, Short (AS-06-015) (3 SEMC); Road between Puerto Ayacucho and Samariapo, small stream, gravel/rock substrate, elev. 60 m, 5° 16.639' N, 67° 48.044' W, 6 i 2006, Short (AS-06-012) (8 SEMC); Territorio Federal Amazonas, Puerto Ayacucho (40 km S.), at Tobogan , sandy margins, colln. #10, 23 ii 1986, P. J. Spangler (1 USNM).

Differential Diagnosis. A small species with a distinct pronotal macula, rather coarse dense dorsal punctation, and a distinct pronotal scintilla. Pronotal foveae PF2 are distinct, and the punctures posterior to the foveae are quite dense, often separated only by narrow walls. The elytra have many subserial or random punctures, and the interstices are small, ca. 0.5–1xpd. The mesoventral process is quite narrow, and the metaventral plaques are carinate. Similar in size and metaventral plaques, and somewhat similar in dorsal habitus to H. tobogan ( Figs. 49 , 52 ); differing therefrom by the less impressed pronotal foveae, lacking the T-shaped PF1 present in H. tobogan , and having a greater degree of randomness of the punctures on the elytra. The aedeagi of the two species differ markedly ( Figs. 51, 54).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.25/0.52; head 0.21/0.33; pronotum 0.31/0.42, PA 0.35, PB 0.37; elytra 0.73/0.52. Dorsum of head dark brown to piceous; pronotum brown around rectangular piceous macula, ratios of color bands, as measured in midline, ca. 6/10/4; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker.

Frons punctures ca. 0.5–1xef, denser near eyes than medially; interstices laterally microreticulate, dull, ca. 0.5– 1xpd, medially effacedly microreticulate, very weakly shining, ca. 1xpd. Clypeus microreticulate, dull, very finely sparsely punctulate medially. Mentum microreticulate and very sparsely very finely punctulate, dull; postmentum very finely densely micropunctulate, dull. Genae raised, shining, without posterior ridge.

Pronotum weakly arcuate laterally; anterior margin straight behind eyes, emarginate behind frons except slightly produced at distinct scintilla; punctures on disc much larger and deeper than those on frons, interstices shining, 0.5–1xpd on disc, punctures denser at anterior and posterior, many separated by narrow walls; PF1 shallow; PF2 shallow; PF3 deep; PF4 shallow; PF3 and PF4 shallowly confluent.

Elytra weakly arcuate laterally; summit of posterior declivity at about midlength; lateral explanate margins moderately wide; many punctures subserial or random, more distinctly serial near suture; on basal 1/3 punctures slightly smaller than largest pronotal punctures, punctures becoming slightly smaller and more widely spaced toward posterior. Intervals and interstices not raised, weakly shining, on basal 1/3 ca. 0.5–1xpd. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1.5/0.5/3/5. P1 laminate; median carina sinuate in profile. P2 narrow, l/w ca. 3/1, sides parallel, apex rounded, raised slightly above mesoventral intercoxal process. Plaques very narrow, carinate lines, straight, slightly converging toward one another anteriorly, located at sides of deep median depression. Metaventrite with very small point on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at straight posterior margin ca. 2x P2. Protibia very slightly arcuate, if at all. Meso- and metatibia slender, straight. Abdominal apex very slightly asymmetrical; last tergite with apicomedian notch. Female not yet known.

Etymology. Named in reference to the head/scintilla stridulatory structure, and the whip-like aedeagal flagellum.

Distribution. Currently known only from the type locality and nearby sites ( Fig. 197).

Figures

FIGURE 49. Hydraena tobogan, holotype, dorsal and lateral habitus, and venter.

FIGURE 52. Hydraena reverberata, holotype, dorsal and lateral habitus, and venter.