Hydraena ambohitantely, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 108-109

Hydraena ambohitantely , new species

Figs. 97 (habitus), 10 (aedeagus), 274 (map)

Type Material. Holotype (male): Antananarivo, Ambohitantely Spec. Res., sifting forest litter, Winkler app. extr., elev. 1593 m, 18° 10' S, 47° 17' E, 19 iv 2011, L.S. Rahanitriniaina, P. Banar, R. Raveloson ( ABT /01/2011) ( MMBC). Paratypes: Same data as holotype (105 MMBC).

Differential Diagnosis. Very similar in size and habitus to H. marojejy ; differing therefrom in having more finely punctate elytra, longer elytra and shorter pronotum, and narrower metaventral plaques. The aedeagi of the two species are immediately differentiated ( Figs. 10, 91).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.83/0.84; head width 0.43; pronotum 0.41/0.63, PA 0.50, PB 0.52; elytra 1.22/0.84.

Dorsum reddish brown, head darker than pronotum and elytra; legs brown to reddish brown; maxillary palpi light brown, distal ½ of last palpomere not darker.

Head with clypeus finely sparsely punctate; frons more coarsely punctate laterally than medially where interstices ca. 1–2xpd. Pronotum in anterior and posterior 1/3 moderately densely punctate, interstices 1–2xpd; punctures on disc distinctly smaller, interstices ca. 2–5xpd, shining. Mentum microreticulate, dull; postmentum microreticulate medially. Genae raised, shining, with posterior ridge, interrupted in midline.

Pronotum arcuate laterally; anterior margin straight behind eyes, emarginate behind frons; PF1 shallow, margins ill-defined; PF2 absent; PF3 moderately deep; PF4 shallow.

Elytra weakly arcuate laterally; summit of posterior declivity slightly before midlength; lateral explanate margins wide; serial punctures very slightly rectangular, each with minute granule at anterior margin, separated by ca. 1–2xpd, slightly smaller than largest pronotal punctures. Intervals not raised, weakly shining, ca. 1– 2x puncture width. 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. 1/2/3/1. P1 as wide as P2; median carina weakly sinuate in profile. P2 narrow, l/w ca. 3/1, sides parallel, apex blunt and on same level as anteromedian carina of metaventrite. Plaques elongate oval, tapering anteriorly, separated by ca. greatest plaque width, very slightly raised, located at sides of median depression. Metaventrite anteromedian carina ca. as long as plaques, not quite attaining anterior level of plaques; long longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at arcuate posterior margin ca. 2x P2. Protibia medial margin straight, lateral margin very weakly arcuate. Mesotibia straight, widest near midlength, medial margin with 3 or 4 short sharp spines, spines longer and stronger from most proximal to most distal, surface of tibia notched between spines, most distal notch deepest. Metatibia very weakly arcuate. Metafemur more strongly arcuate on lateral than medial margin. Abdominal apex with narrow apicomedian notch.

Etymology. Named in reference to the geographical distribution.