Hydraena jubata, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 91-93

Hydraena jubata , new species

Figs. 81 (habitus), 83 (aedeagus), 266 (map)

Type Material. Holotype (male): Antsiranana, 14.4346S 49.7606E Sava Marojejy NP, forest stream above Camp II, forest stream with rocks and gravel, elev. 710 m, E, 10 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren ( MAD 14-58) ( NHRS). Paratypes: Same data as holotype (1 NHRS).

Differential Diagnosis. Similar to H. sculponea in general habitus, size, reddish brown color, and the possession of arcuate metatibiae; distinguished therefrom by the differently shaped metaventral plaques, which are carinate and more widely separated from one another in H. jubata . The aedeagi of the two species are markedly dissimilar ( Figs. 83, 84).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 2.08/0.83; head width 0.49; pronotum 0.49/0.66, PA 0.49, PB 0.52; elytra 1.33/0.83.

Dorsum general coloration reddish brown; head darker than pronotum, almost piceous; pronotum with large, darker rectangular macula, with lighter surrounding areas; elytra almost as dark as pronotal fascia, except lighter humeral angles; legs light brown to brown; maxillary palpi light brown, distal ½ of last palpomere not darker.

Head with clypeus moderately finely and moderately densely punctate; frons coarsely densely punctate, punctures separated by narrow walls laterally, medially interstices narrow walls to ca. 1xpd, each puncture with short distinctive seta. Pronotum coarsely densely punctate, interstices ca. 0.5xpd, shining. Mentum Mentum moderately coarsely, punctate, interstices dull or very weakly shining; postmentum finely densely punctate. Genae raised, rugulose, with posterior ridge, interrupted in midline.

Pronotum bisinuate laterally; anterior margin straight behind eyes, emarginate behind frons; PF1 and PF2 absent; PF3 shallow; PF4 very shallow; PF3 and PF4 shallowly confluent.

Elytra weakly arcuate laterally; summit of moderately steep posterior declivity at ca. midlength; lateral explanate margins wide, edges denticulate; serial punctures large, round, separated by ca. 0.5xpd or less, sometimes narrow walls, ca. same size as largest pronotal punctures. Intervals not raised, shining, very narrow, sometimes zig-zag shape due to large punctures. Apices in dorsal aspect rather sharply conjointly rounded, in posterior aspect margins not forming angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/0.75/3/2. P1 as wide as P2; median carina very weakly sinuate in profile. P2 l/w ca.2/1, sides parallel, apex blunt and on same level as anteromedian carina of metaventrite. Plaques roundly raised posteriorly, each narrowing and converging anteriorly, becoming carinate where joining anteromedian carina, separated basally by ca. 2x plaque width, located at sides of median depression. Metaventrite anteromedian carina shorter than plaques, length as 2 to 3, joining anterior carinae of plaques, together forming inverted Y-shape; long and strong, slightly arcuate longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at arcuate posterior margin ca. 2x P2. First abdominal ventrite deeply concave behind AIS. Legs rather long. Protibia straight, slender. Mesotibia slightly arcuate, medial margin distal 1/3 with 3 or 4 short sharp spines, surface of tibia notched between spines. Metatibia slightly arcuate, slender. Metafemur moderately slender. Abdominal apex with small apicomedian notch.

Etymology. Named in reference to the prominent crest-like row of setae on the apex of the paramere.