Hydraena andranomena, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 130-132

Hydraena andranomena , new species

Figs. 116 (habitus), 118 (aedeagus), 284 (map)

Type Material. Holotype (male): Toliara, Andranomena , at black light, dry forest near open marsh, 19° 53' S, 45° 4' E, 30 iii 1990, W. E. Steiner, C. Kremen, V. Razafimahatratra ( USNM).

Differential Diagnosis. Somewhat similar in size (ca. 1.49 vs. 1.39 mm), color, and shape to H. torquata ; differing externally therefrom in having the pronotum proportionally longer, with much finer and sparser discal punctation, and shallower PF2 foveae; metaventral plaques are larger in H. torquata . The aedeagi of the two species are markedly dissimilar ( Figs. 118 , 121).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.49/0.61; head width 0.38; pronotum 0.37/0.51, PA 0.39, PB 0.45; elytra 0.90/0.61.

Head and pronotal disc dark brown, almost piceous, remainder of dorsum dark brown, except anterior margin of pronotum lighter; legs brown; maxillary palpi brown, distal 0.5 of last palpomere not darker.

Head with frons moderately densely punctate, clypeus finely punctate, microreticulate, dull. Pronotum moderately densely moderately finely punctate in anterior and posterior, disc very finely and sparsely punctate, interstices 3–6xpd, strongly shining. Mentum finely punctate; postmentum punctate. Genae roundly raised, medially smooth and shining, without posterior ridge.

Pronotum slightly sinuate laterally, very slightly emarginate between anterior angle and widest part of pronotum; anterior margin straight behind eyes, very slightly emarginate behind frons; PF1 absent; PF2 moderately deep, very shallowly, if at all, confluent medially; PF3 deep; PF4 shallow.

Elytra weakly arcuate laterally; summit of posterior declivity near midlength; lateral explanate margins narrow; serial punctures round, separated by ca. 1xpd, slightly larger than largest pronotal punctures. Intervals not raised, ca. 1–2xpd, weakly shining. 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. 1/0.5/2/1. P1 laminate; median carina sinuate in profile. P2 l/w ca. 2/1, sides parallel, apex blunt and raised slightly above metaventral intercoxal process. Plaques small, narrow and indistinct, partially obscured by pubescence, converging slightly anteriorly, not raised, located at sides of median depression. Metaventrite with very short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at arcuate posterior margin ca. 1.5x P2. Protibia very slightly arcuate, almost straight, slightly widened at ca. distal ¼. Mesotibia straight, widest at ca. midlength. Metatibia straight, slender. Metafemur slender, not markedly arcuate on lateral and medial margins. Abdominal apex with deep asymmetrical notch.

Etymology. Named in reference to the type locality.

Figures

FIGURES 117 – 118. Aedeagi of Hydraena regimbarti, non-type, and Hydraena andranomena, holotype.