Hydraena upsilonica,

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264: 85-86

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Hydraena upsilonica

new species

Hydraena upsilonica  , new species

Figs. 74 (habitus), 76 (aedeagus), 226 (gonocoxite and spermatheca), 263 (map)

Type Material. Holotype (male): Toamasina, Zahamena NP, btw Camp Site 2 and Fenerive Est : "route des contrebandiers", dry stream with pools, N:-17.54167, E:48.72183, elev. 1322 m, 2 i 2007, Isambert et al. (P60BI29) ( NHRS)  . Paratypes (45): Same data as holotype (33); Antananarivo, 18.4133S 47.9443E Analamanga, 10km E of Anjozorobe, Anjozorobe forest reserve, forest stream next to Saha forest camp, elev. 1240 m, 18° 24' S, 47° 56' E, 23 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren ( MAD14-77View Materials) (4 NHRS)GoogleMaps  ; Tampoketsan Ankazobe (Antananarivo), spring stream exp. W, W from R.N.4 (km 157), elev. 1400 m, 18° 20' S, 47° 10' E, 29 xi 2001, Gerecke & Goldschmidt (MD 169) (5 NMW)GoogleMaps  ; Toamasina, Alaotra-Mangoro: Zahamena NP; stream on the way to Camp 2 (cascade), S 17.6725 E 48.80361, GB nets and sieves, drying up stream with side pools, elev. 1318 m, 17° 40' S, 48° 48' E, 19 iii 2013, J.H. Randriamihaja & T.Ranarilalatiana (ZAH13-06) (2 NHRS)GoogleMaps  .

Differential Diagnosis. Somewhat similar in dorsal habitus to H. tibiodentipes  ; differing therefrom in several characters, including smaller size (ca. 1.90 vs. 2.21 mm), longer and more coarsely punctate elytra, differently shaped plaques, different pronotal color, and markedly dissimilar aedeagi. The aedeagus clearly shows a relationship to H. compacta  , which see.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.90/0.79; head width 0.47; pronotum 0.43/0.60, PA 0.49, PB 0.50; elytra 1.14/0.79.

Dorsum general coloration reddish brown; head darker than pronotum, almost piceous; pronotum with large, darker fascia, anterior and posterior borders lighter; elytra almost as dark as pronotal fascia, except lighter humeral angles; legs light brown to brown; maxillary palpi testaceous, distal ½ of last palpomere not darker.

Head with clypeus finely moderately densely punctate; frons slightly more coarsely punctate laterally than medially where interstices ca. 1–3xpd, each puncture with short distinctive seta. Pronotum in anterior and posterior 1/3 more densely punctate than on disc, interstices narrow walls to ca. 1xpd; punctures on disc smaller, interstices ca. 0.5–1xpd, shining. Mentum finely punctate, shining; postmentum subscabrous. 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 deep; PF4 moderately deep; PF3 and PF4 shallowly confluent.

Elytra weakly arcuate laterally; summit of moderately steep posterior declivity at ca. midlength; lateral explanate margins wide; serial punctures large, round, separated by ca. 0.5xpd or less, slightly larger than largest pronotal punctures. Intervals not raised, shining, very narrow, sometimes zig-zag shape due to large punctures. 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. 1/0.5/3/1.3. P1 as wide as P2; median carina very weakly sinuate in profile. P2 l/w ca. 2/1, sides converging slightly posteriorly, apex blunt and on same level as anteromedian carina of metaventrite. Plaques carinate, converging anteriorly and joining anteromedian carina, together forming inverted Y-shape, separated basally by ca. 3x plaque width, located at sides of median depression. Metaventrite anteromedian carina ca. same length as plaques; long longitudinal and slightly arcuate ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at arcuate posterior margin ca. 1.5x P2. Protibia straight, slender. Mesotibia straight or very slightly arcuate, 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, most distal notch deepest. Metatibia very slightly arcuate, nearly straight, slender. Metafemur slender, arcuate on lateral margin, very weakly sinuate on medial margin. Abdominal apex with narrow apicomedian notch. Etymology. Named in reference to the inverted Y-shaped metaventral carinae.


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