Hydraena fulgidicollis, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 146-147

Hydraena fulgidicollis , new species

Figs. 132 (habitus), 134 (aedeagus), 292 (map)

Type Material. Holotype (male): Antananarivo, Parc de Tsimbazaza , yellow pan trap, 18° 56' S, 47° 31' E, 21–25 x 1984, Robert W. Brooks (70) (1 SEMC) ; same locality, 18° 56' S, 47° 31' E, 1–6 xi 1984, R. W. Brooks (70) ( SEMC) . Paratypes (6): Same data as holotype (1 SEMC). Antananarivo, 18.4128S 47.9439E Analamanga Anjozorobe forest reserve Marsh next to stream, by Saha forest , 10km E of Anjozorobe, forest marsh, elev. 1320 m , 18° 24' S, 47° 56' E, 23 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren (MAD14-78) (5 NHRS).

Differential Diagnosis. Similar to H. randriamihajai in size (ca. 1.68 vs. 1.65 mm), pronotal foveae, general habitus, and male metatibiae having a small brush of setae; differing therefrom in being more finely sparsely punctate and more strongly shining dorsally, having shorter plaques, and lacking a patch of long setae on the prosternum. In both species the only pronotal fovea present is PF3. The aedeagi of the two species differ markedly ( Figs. 134, 138).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.68/0.73; head width 0.38; pronotum 0.43/0.57, PA 0.44, PB 0.54; elytra 1.04/0.73.

Dorsum brown except head piceous, pronotum disc darker than surrounding areas, and darker than elytra; legs testaceous; maxillary palpi testaceous, distal ½ of last palpomere not darker.

Head with clypeus very finely very sparsely punctulate, frons finely sparsely punctate, interstices shining. Pronotum finely sparsely punctate, especially finely and sparsely on disc; interstices ca. 5–6xpd, or greater, on disc, strongly shining. Mentum sparsely finely punctulate, weakly shining; postmentum sparsely punctate, weakly shining. Genae raised, smooth, shining, without posterior ridge.

Pronotum moderately arcuate laterally; anterior margin straight behind eyes, emarginate behind frons; PF1, PF2 and PF4 absent; PF3 large, moderately deep.

Elytra weakly arcuate laterally; summit of posterior declivity near midlength; lateral explanate margins narrow; serial punctures small, round, separated by ca. 3–6xpd, ca same size as pronotal punctures. Intervals not raised, shining, ca. 3xpd. Apices in dorsal aspect separately, weakly rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/0.75/1.2/2. P1 laminate; median carina sinuate in profile. P2 narrow, l/w ca. 2/1, sides parallel, blunt apex raised slightly above mesoventral intercoxal process. Plaques small, oval, margins indistinct, not raised, located at sides of very shallow median depression. AIS width at slightly arcuate posterior margin ca. 2x P2. Protibia and Mesotibia very slightly arcuate. Metatibia very slightly arcuate, almost straight, distal 1/3 of medial margin with small, indistinct brush of setae in unilinear row. Abdominal apex with apicomedian notch.

Etymology. Named in reference to the brightly shining pronotum.