Hydraena umbolenta, 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 : 53

Hydraena umbolenta , new species

Figs. 108 (habitus), 111 (aedeagus), 184 (spermatheca), 202 (map)

Type Material. Holotype (male): Paraguay: Rio Tebicuarymi, shore washing, 26° 25' S, 56° 50' W, 20 i 1991, S. Endrody-Younga (PAR-248). Deposited in the TMSA. Paratypes: Same data as holotype (9 TMSA).

Differential Diagnosis. Dorsal habitus very similar to H. kellymilleri and H. loripes ( Figs. 108–110 ). In general, H. umbolenta is more coarsely punctate dorsally than the compared species, but the pronotum lacks foveae PF2, which are present in the two other species. In addition, males are differentiated by the thickened protibiae, and females by the non-serrate last tergite. The aedeagi of the three species, while having distinctively different details, also show a relationship ( Figs. 111–113).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.25/0.54; head 0.22/0.32; pronotum 0.30/0.40, PA 0.36, PB 0.39; elytra 0.77/0.54. Dorsum of head piceous; pronotum testaceous in front of and behind piceous fascia, ratios of color bands, as measured in midline, ca. 5/10/5, fascia laterally smaller and more lightly colored; elytra brown, columellae darker than interstices; legs testaceous; maxillary palpi testaceous, tip not darker.

Frons punctures ca. 1xef, not larger and denser near eyes; interstices effacedly microreticulate, weakly shining, 0.5–1xpd. Clypeus dull, microreticulate, 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 weakly arcuate laterally; anterior margin straight behind eyes, emarginate behind frons, scintilla absent; punctures on disc larger and deeper than those on frons, interstices shining, 0.5–2xpd, punctures larger and denser at anterior and posterior; PF1, PF2 and PF4 absent; PF3 deep.

Elytra weakly arcuate laterally; summit of posterior declivity at ca. midlength; lateral explanate margins narrow; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, punctures becoming slightly smaller and more widely spaced toward posterior. Intervals not raised, shining, on basal 1/3 ca. 0.5–1xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2.1/1/5/4. P1 laminate; median carina sinuate in profile. P2 l/w ca. 4/2.5, sides parallel, apex blunt, raised slightly above mesoventral intercoxal process. Plaques very narrow, subcarinate lines, straight, slightly converging toward one another anteriorly, located at sides of deep median depression. Metaventrite with very short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at straight posterior margin ca. 1.5x P2. Protibia arcuate, moderately thick. Mesotibia straight. Metatibia arcuate, slender, very slightly widened subapically. Male abdominal apex symmetrical; last tergite with apicomedian notch. Female abdominal apex: last tergite broadly rounded, without apicomedian notch, ca. 45 (n=1) hooked setae, tips sharply pointed; gonocoxite not midlongitudinally divided, apical margin sharply rounded, no transverse ridge evident at border of microreticulation. Spermatheca type C1.

Etymology. Named in reference to the many small bumps on the dorsal face of the aedeagal distal piece.

Distribution. Currently known only from the type locality ( Fig. 202).

Figures

FIGURE 108. Hydraena umbolenta, holotype, dorsal and lateral habitus, and venter.

FIGURE 109. Hydraena kellymilleri, holotype, dorsal and lateral habitus, and venter.

FIGURE 110. Hydraena loripes, holotype, dorsal and lateral habitus, and venter.