Hydraena goldschmidti, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 56-57

Hydraena goldschmidti , new species

Figs. 45 (habitus), 47 (aedeagus), 248 (map)

Type Material. Holotype (male): Antananarivo, Anjozorobe, Ravoandrina , Riv. Ampanakamonty near campsite, lower course forest, elev. 1280 m, 18° 13' S, 47° 31' E, 21 vii 2001, Gerecke & Goldschmidt (MD 11b) ( NMW) . Paratypes (26): Antananarivo, Anjozorobe (Antananarivo), Ravoandrina, Riv. Ampanakamonty near campsite, elev. 1280 m, 18° 13' S, 47° 31' E, 21 vii 2001, Gerecke & Goldschmidt (MD 11c) (3 NMW); Anjozorobe (Antananarivo), Ravoandrina , Ruisseau Andohana Andreba (affl. of Riv. Ampanakamonty), pool, elev. 1250 m, 18° 13' S, 47° 31' E, 25 vii 2001, Gerecke & Goldschmidt (MD 15a) (4 NMW); Anjozorobe (Antananarivo), Ravoandrina , small str. at campsite, near forest border, elev. 1280 m, 18° 13' S, 47° 31' E, 18 vii 2001, Gerecke & Goldschmidt (MD 9) (17 NMW); Anjozorobe (Antananarivo), Ravoandrina , spring stream near water capturing for the village, elev. 1350 m, 18° 13' S, 47° 31' E, 19 vii 2001, Gerecke & Goldschmidt (MD 10) (2 NMW).

Differential Diagnosis. Differentiated from other members of the group by the widely separated, narrow metaventral plaques, which are separated by about three times the width of a plaque. The aedeagus is easily distinguished from that of other members of the group.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.44/0.65; head width 0.35; pronotum 0.33/0.49, PA 0.38, PB 0.41; elytra 0.83/0.65.

Dorsum dark brown to reddish dark brown, frons darkest, pronotum with diffusely margined macula surrounded by slightly lighter color; legs brown; maxillary palpi light brown, distal ½ of last palpomere sometimes slightly darker.

Head with clypeus very finely sparsely punctate and microreticulate, dull; frons punctures much larger and denser, interstices ca. 1–2xpd, shining. Pronotum moderately finely punctate; punctures in anterior and posterior 1/ 3 larger than those of head, interstices narrow walls to 1xpd; disc punctures sparser, interstices ca. 2–3xpd, shining. Mentum very sparsely very finely punctulate, microreticulate, dull; postmentum microreticulate in shallow median depression, dull, lateral areas shining. Genae raised, shining, with well demarcated posterior ridge, interrupted in midline.

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

Elytra weakly arcuate laterally; posterior declivity steep, summit near midlength; elytra quite convex in posterior 0.5; lateral explanate margins moderately wide; serial punctures fine and sparse, round, basally about same size as pronotal punctures, becoming very fine over posterior declivity. Intervals not raised, shining, ca. 2– 3xpd. Apices in dorsal aspect conjointly rounded, in posterior aspect margins do not form angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/0.5/2/1.5. P1 as wide as P2; median carina weakly sinuate in profile. P2 l/w ca. 1.5/1, sides parallel, apex blunt and at same level as anteromedian carina of metaventrite. Plaques moderately large, elongate oval, widely separated, not parallel, more narrowly separated anteriorly than posteriorly, roundly raised, located at sides of median depression. Metaventrite anteromedian carina slightly longer than plaques, terminating between anterior extremes of plaques; long longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity to slightly past midlength of metaventrite. AIS width at slightly arcuate posterior margin ca. 1.5x P2. All tibiae straight, slender. Mesotibia medial margin slightly past midlength with 4–5 short stout spines, margin notched between spines. Metafemur lateral margin arcuate, medial margin weakly bisinuate. Abdominal apex with very small apicomedian notch.

Etymology. Named in honor of the collector, Tom Goldschmidt.