Hydraena clinodorsa, 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 : 32-33

Hydraena clinodorsa , new species

Figs. 48 (habitus), 50 (aedeagus), 197 (map)

Type Material. Holotype (male): Bolivia: Yungas Val., 12–13 vi 1937, H. E. Hinton. Deposited in the TMSA.

Differential Diagnosis. A moderately sized, quite convex species that, in lateral profile, is markedly arcuate. The pronotum is subcordiform, and has a large piceous fascia; color band ratios ca. 5/20/5. The dorsal punctation is sparse and the interstices are strongly shining. The dorsal habitus is not easily compared with that of another species ( Fig. 48 ). The male genitalia show some similarity in basic plan to that of H. cherylbarrae , but the two differ markedly in many ways ( Figs. 26, 50).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.63/0.71; head 0.30/0.40; pronotum 0.40/0.54, PA 0.43, PB 0.45; elytra 1.03/0.71. Dorsum of head piceous; pronotum light brown in front of and behind large piceous fascia, ratios of color bands, as measured in midline, ca. 5/20/5; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker.

Frons punctures ca. 0.5–1xef, larger and denser near eyes than medially; interstices laterally microreticulate, dull, ca. 0.5–1xpd, medially shining, ca. 1–5xpd. Clypeus microreticulate laterally, very finely sparsely punctulate medially. Mentum very sparsely very finely punctulate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge.

Pronotum moderately arcuate laterally, subcordiform; anterior margin straight behind eyes, very weakly emarginate behind frons extremely slightly produced at middle, scintilla absent; punctures on disc ca. 1xpd of largest punctures on frons, interstices strongly shining, ca. 2–6xpd on disc, punctures slightly denser at anterior and posterior; PF1 shallow; PF2 very shallow, obsolete; PF3 very deep; PF4 shallow; area between PF3 and PF4 convex.

Elytra strongly convex, moderately arcuate laterally; summit of posterior declivity well before midlength; lateral explanate margins moderately wide; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, punctures becoming smaller and more widely spaced toward posterior. Intervals not raised, strongly shining, on basal 1/3 ca. 1–3xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming very shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/0.5/4/5. P1 laminate; median carina sinuate in profile. P2 l/w ca. 3/1, sides slightly converging toward blunt apex. Plaques very narrow lines, straight, slightly converging toward one another anteriorly, weakly raised, located at sides of shallow median depression. Metaventrite without a ridge extended posteriorly from margin of each mesocoxal cavity. AIS width at straight posterior margin ca. 1.5x P2. Protibia gradually, moderately widened from base to ca. distal 2/3, then emarginate to apex, few moderately long setae at widest part. Meso- and metatibia slender, straight. Abdominal apex very slightly asymmetrical. Females not yet known.

Etymology. Named in reference to the markedly declivous dorsum, front and rear, in lateral aspect. Distribution. Currently known only from the type locality ( Fig. 197).

Figures

FIGURE 48. Hydraena clinodorsa, holotype, dorsal and lateral habitus, and venter.