Hydraena renalisa

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264: 124-125

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Hydraena renalisa

new species

Hydraena renalisa  , new species

Figs. 111 (habitus), 113 (aedeagus), 281 (map) Type Material. Holotype (male): Antsiranana, Sambava: Marojejy NP, Camp 2 long waterfall along smooth rock area (hygropetric), N:-14.43400, E:49.75633, elev. 717 m, 14° 26' S, 7 xii 2006, Isambert et al. (P57 Bi 12) ( NHRS)  . Paratypes (27): Same data as holotype (2); Antsiranana, 14.4345S 49.7606E Sava Marojejy NP Camp II, wide river forming hygropetric rocks, wide river forming hygropetric rocks and rockpools, elev. 710 m, 14° 26' S, 49° 45' E, 9 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren ( MAD14-54View Materials) (1 NHRS)GoogleMaps  ; Antsaba, Galoko Mountains , hygropetric cascade, elev. 303 m, 13° 39' S, 48° 45' E, 1 xi –29 xii 2004, M. Balke (MD 016) (2 ZSMC)GoogleMaps  ; Sava, Marojejy NP, 800m N from Camp I, Humbert waterfall; 14.4333S 49.773E, ex. bedrock pools at side of waterfall, elev. 550 m, 14° 26' S, 49° 46' E, 8 xi 2014, P. D. Perkins ( MAD14-48View Materials) (22 MCZ)GoogleMaps  .

Differential Diagnosis. The most truncate member of the species group (1.65 x 0.72 mm; l/w ca. 2.29). Habitus otherwise somewhat similar to that of H. divisa  , but markedly differing therefrom in form of the metaventral plaques. The basic form of the aedeagi show some vague resemblance but differ in many shapes and, especially, the two parameres present in H. renalisa  ( Figs. 109, 112View FIGURE 112).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.65/0.72; head width 0.40; pronotum 0.41/0.56, PA 0.44, PB 0.49; elytra 0.99/0.72.

Dorsum dark brown to piceous, head darkest; legs brown; maxillary palpi light brown, distal 0.5 of last palpomere (except tip) slightly darker.

Head with dorsal punctation very uniform, moderately coarse and dense; interstices narrow walls to ca. 0.5xpd, very weakly shining. Mentum finely sparsely punctulate, interstices strongly shining; postmentum densely, more coarsely punctate, subscabrous. Genae raised, medially smooth and shining, subscabrous laterally, without posterior ridge.

Pronotum slightly bisinuate laterally; anterior margin straight behind eyes, very slightly emarginate behind frons. Pronotal punctures larger than those of head, dense and quite uniform in size, some punctures confluent, interstices usually narrow walls, rarely ca. 0.5xpd, very weakly shining. PF1 shallow; PF2 shallow, very shallowly confluent medially; PF3 deep; PF4 moderately deep.

Elytra weakly arcuate laterally; summit of posterior declivity near midlength; lateral explanate margins moderately wide; serial punctures round, very closely spaced, separated by ca. 0.5xpd or less, slightly larger than pronotal punctures. Intervals very slightly raised, ca. 0.5xpd or less, very 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. 1/1.5/4/1.5. 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 large, oval or slightly kidney shaped, parallel, very slightly raised, located at sides of median depression. Metaventrite with very short process on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at arcuate posterior margin ca. 2x P2. Legs stout. Protibia arcuate. Mesotibia straight, widest at ca. midlength; does not possess row of prominent spines as present in Monomadraena species. Metatibia arcuate, medial margin with small brush of setae in distal 0.5. Metafemur arcuate on lateral margin and rather strongly bisinuate on medial margin. Abdominal apex with deep slightly asymmetrical notch.

Etymology. Named in reference to the kidney-shaped metaventral plaques.


Swedish Museum of Natural History, Entomology Collections


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Museum of Comparative Zoology


Academie imperial des Sciences