Hydraena spatula, 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 : 59

Hydraena spatula , new species

Figs. 122 (habitus), 124 (aedeagus), 198 (map)

Type Material. Holotype (male): Venezuela : Trujillo, NW Humocaro Bajo, side pools along road, elev. 1843 m, 9° 41.99' N, 70° 1.812' W, 12 vii 2009, Garcia, Cacha (VZ09-0712-02B). Deposited in the MIZA. Paratypes (7): Same data as holotype (6 SEMC); Lara, P. N. Yacambu, 6.4 km SE Sanare, cloud forest litter, elev. 1850 m, 9° 41' N, 69° 38' W, 17 v 1998, R. Anderson (014D) (1 SEMC).

Differential Diagnosis. A moderately coarsely densely punctate species, with most punctures having a rather distinctive recumbent seta. The pronotum does not appear to have a distinct fascia (in mature specimens). The elytra have a rather wide explanate margin. Similar in habitus to H. altiphila ( Figs. 122–123 ); differentiated therefrom by the larger size (ca. 1.85 vs. 1.69 mm), the narrower form, the narrower P2 and longer plaques (plaque ratios ca. 2/1.5/9/4 vs. 2.5/1/6/4), and differences in the male legs. Males have the metafemur with a distinctive brush of setae along the medial margin, and the metatibia is very slightly arcuate, slightly widened in distal 1/4, and the entire medial margin has a narrow row of short, recumbent setae. The aedeagi of the two species differ markedly, but show a general plan similarity, and stand apart from other species by the very large distal lobe ( Figs. 124– 125).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.85/0.78; head 0.27/0.43; pronotum 0.43/0.60, PA 0.48, PB 0.53; elytra 1.15/0.78. Dorsum of head piceous; pronotum dark brown, except brown anterior angles (teneral specimens appear to have indistinct fascia); elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker.

Frons punctures ca. 1–1.5xef, larger and denser near eyes than medially; interstices shining, 0.5–1xpd laterally, 1–2xpd medially. Clypeus microreticulate laterally, very finely sparsely punctulate medially. Each puncture on frons and clypeus with distinctive recumbent seta. Mentum very sparsely very finely punctulate, shining; postmentum very finely densely micropunctulate in median concavity, anterior area smooth, shining. Genae raised, shining, with very low median tumidity, without posterior ridge.

Pronotum moderately arcuate laterally; anterior margin straight behind eyes, emarginate behind frons, scintilla absent; punctures on disc slightly larger than largest punctures on frons, interstices shining, 1–3xpd, punctures larger and denser at anterior and posterior; PF1 absent; PF2 very shallow; PF3 deep; PF4 shallow; PF3 and PF4 very shallowly confluent.

Elytra weakly arcuate laterally; summit of posterior declivity at ca. midlength; lateral explanate margins wide; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, punctures becoming finer and more widely spaced toward posterior. Intervals not raised, shining, on basal 1/3 ca. 2xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly rather sharply rounded, in posterior aspect margins forming very shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/1.5/9/4. P1 laminate; median carina sinuate in profile. P2 narrow, l/w ca. 3/1, sides slightly converging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques moderately wide, slightly arcuate, slightly converging toward one another anteriorly, weakly raised, 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. 2.5x P2. Protibia slightly arcuate, medial margin distinctly widened at ca. distal 1/4 and here bearing moderately long setae. Mesotibia slen- der, very slightly arcuate, if at all. Metafemur with distinctive brush of setae along medial margin. Metatibia very slightly arcuate, slightly widened in distal 1/4, entire medial margin with narrow row of short, recumbent setae. Male abdominal apex slightly asymmetrical; last tergite with deep apicomedian notch. Female (microslide mount, n=1): last tergite sharply rounded, without apicomedian notch, ca. 30 moderately long, hooked setae, separated by small apicomedian gap; gonocoxite not midlongitudinally divided, apical margin sharply rounded, low transverse ridge evident at border of microreticulation; spermatheca type C1, duct very long and convoluted.

Etymology. Named in reference to the spatula-shaped aedeagus.

Distribution. Currently known from two narrowly separated localities in northwestern Venezuela ( Fig. 198).

Figures

FIGURE 122. Hydraena spatula, holotype, dorsal and lateral habitus, and venter.

FIGURE 123. Hydraena altiphila, holotype, dorsal and lateral habitus, and venter.