Hydraena simplicata, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 60-61

Hydraena simplicata , new species

Figs. 49 (habitus), 51 (aedeagus), 250 (map)

Type Material. Holotype (male): Antsiranana, Montagne d'Ambre, Grande Cascade , stream parallel to, elev. 800 m, 13° 34' S, 49° 10' E, 1 xi–30 xii 2004, M. Balke & D. Ottke (MD 005) ( ZSMC) . Paratypes (74): Same data as holotype (41); Antsiranana, Antsaba,Galoko Mountains, hygropetric cascade, elev. 303 m, 13° 39' S, 48° 45' E, 1 xi–29 xii 2004, M. Balke (MD 016) (8 ZSMC); Joffreville, (M.d'Ambre, Antsiranana) , Cascade sacre , spring affluent crossing road 30 m below, elev. 1043 m, 12° 31' S, 49° 10' E, 30 iii 2011, R. Gerecke (MD 192) (1 NMW); Joffreville (M.d'Ambre, Antsiranana) , first right affl. below Grande Cascade, in steep forest valley, elev. 1154 m, 12° 30' S, 49° 10' E, 26 iii 2011, R. Gerecke (MD 186) (3 NMW); Joffreville (M.d'Ambre, Antsiranana) , left affl. R. de Manques in Reserve Fontenay , riffle, elev. 600 m, 12° 32' S, 49° 10' E, 7 xi 2001, Gerecke & Goldschmidt (MD 155a) (2 NMW); Joffreville (M.d'Ambre, Antsiranana) , R.Antomboka b/n station forestiere and cascade, riffle, elev. 950 m, 12° 32' S, 49° 10' E, 19 xi 2001, Gerecke & Goldschmidt (159a) (1 NMW); Joffreville (M.d'Ambre, Antsiranana) , R.Antomboka downstr. large cascade, elev. 850 m, 12° 32' S, 49° 10' E, 12 xi 2001, Gerecke & Goldschmidt (MD 165) (3 NMW); Joffreville (M.d'Ambre, Antsiranana) , R.Antomboka downstr. large cascade, riffle, elev. 850 m, 12° 32' S, 49° 10' E, 21 xi 2011, Gerecke & Goldschmidt (MD 165a) (1 NMW); Joffreville (M.d'Ambre, Antsiranana) , riparian rheocrenes at R.Antomboka downstr. large cascade, elev. 850 m, 12° 32' S, 49° 10' E, 21 xi 2001, Gerecke & Goldschmidt (MD 167) (2 NMW); Joffreville (M.d'Ambre, Antsiranana) , riparian springs at right border of R. Antomboka downstream sacred cascade, elev. 1000 m, 12° 32' S, 49° 10' E, 19 xi 2001, Gerecke & Goldschmidt (MD 160) (2 NMW); Montagne d'Ambre, Grande Cascade, stream parallel to, elev. 800 m, 13° 34' S, 49° 10' E, 1 xi–30 xii 2004, M. Balke & D. Ottke (MD 005) (41 ZSMC) ; Fianarantsoa, Ionilahy (Fianarantsoa), small str. crossing the railroad between the village and site MD 0 27, 23° 34' S, 43° 45' E, 15 viii 2001, Gerecke & Goldschmidt (MD 28) (4 NMW) ; Toliara, Andohahela (Tulear), Fenoevo , stream at N margin of forest, elev. 330 m, 24° 36' S, 46° 42' E, 8 ix 2001, Gerecke & Goldschmidt (MD 64) (1 NMW); Andohahela (Tulear), Isaka, spring area S pass RIP 118 (km 36), spring, elev. 700 m, 24° 48' S, 46° 51' E, 10 ix 2001, Gerecke & Goldschmidt (MD 71a) (4 NMW); Tsimelahy (Tulear), small stream exp. NW, affl. of Riv. Antarantsa, elev. 360 m, 24° 56' S, 46° 38' E, 4 ix 2001, Gerecke & Goldschmidt (MD 59) (1 NMW).

Differential Diagnosis. Similar in dorsal habitus and shape of the metaventral plaques to H. mahavavona ; differing therefrom in having more convex elytra, more ovate margins of the elytra, and color. The aedeagi of the two species differ markedly ( Figs. 51, 56).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.44/0.63; head width 0.38; pronotum 0.33/0.48, PA 0.40, PB 0.41; elytra 0.84/0.63.

Dorsum reddish brown, head darker than pronotum (piceous in darkest specimens); pronotum lighter than elytra and with slightly darker, very diffusely margined macula (laterally almost testaceous in some specimens); legs light brown to testaceous; maxillary palpi testaceous, distal ½ of last palpomere not darker.

Head with clypeus finely sparsely punctate, laterally very weakly microreticulate; frons more coarsely punctate laterally than medially where interstices ca. 2–5xpd. Pronotum in anterior and posterior 1/3 more densely punctate than on disc, interstices ca. 1xpd; punctures on disc distinctly smaller, interstices ca. 3–6xpd, shining. Mentum finely microreticulate, dull; postmentum finely microreticulate medially. Genae raised, shining, with posterior ridge, interrupted in midline.

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

Elytra weakly arcuate laterally; summit of posterior declivity slightly before midlength; lateral explanate margins moderately wide; serial punctures round, separated by ca. 2–3xpd, as large as largest pronotal punctures. Intervals not raised, shining, ca. 2xpd. 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. 1/1/3/1.5. 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 elongate oval, very slightly arcuate and slightly converging anteriorly, separated basally by slightly more than plaque width, slightly raised, located at sides of median depression. Metaventrite anteromedian carina ca. as long as plaques, 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. 1.5x P2. Protibia very slightly arcuate, medial margin with spine-like seta at ca. midlength. Mesotibia straight or very slightly arcuate, widest near midlength, medial margin with 4 or 5 short sharp spines, spines longer and stronger from most proximal to most distal, surface of tibia notched between spines. Metatibia straight, slender. Metafemur slender, more strongly arcuate on lateral than medial margin. Abdominal apex with apicomedian notch.

Etymology. Named in reference to the very simple aedeagus.