Hydraena sinuatipes, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 129

Hydraena sinuatipes , new species

Figs. 112 (habitus), 114 (aedeagus), 283 (map)

Type Material. Holotype (male): Antsiranana, Ankarana, camp, waterhole at Andrafiabe cave entrance, elev. 50 m, 12° 57' S, 49° 8' E, 1 xi–30 xii 2004, M. Balke (MD 021) ( ZSMC) . Paratypes (121): Same data as holotype (32); Antananarivo, Perinet , ex. forest litter, 18° 49' S, 48° 26' E, 12 x 1970, P. Hammond (1 BMNH) ; Antsiranana, 13.2732S 49.6215E Sava Daraina reserve 1,5km SW of camping site, Masomamangi river, Ankijabe village, dried out stream, elev. 290 m, 13° 16' S, 49° 37' E, 3 xi 2014, R. Bukontaite & J.H. Randriamihaja ( MAD14-42 ) (1 NHRS) ; Ankarana, Ampositelo (three fossa creek) en route to Grand Tsingy , elev. 140 m, 12° 57' S, 49° 8' E, 1 xi–30 xii 2004, M. Balke (MD 018) (36 ZSMC) ; Antsaba, Galoko Mountains , hygropetric cascade, elev. 303 m, 13° 39' S, 48° 45' E, 1 xi–29 xii 2004, M. Balke (MD 016) (1 ZSMC) ; 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) (1 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) (1 NMW) ; Montagne d'Ambre , Grande Cascade, elev. 740 m, 13° 34' S, 49° 10' E, 1 xi–30 xii 2004, M. Balke (MD 004) (7 ZSMC) ; Montagne des Francais , stream pool, elev. 171 m, 12° 20' S, 49° 20' E, 1 xi–30 xii 2004, M. Balke & D. Ottke (MD 001) (33 ZSMC) ; Mahajanga, Melaky: Tsingy de Bemaraha NP. S 19.14114 E 0 44.81245, elev. 45 m, 19° 8' S, 44° 49' E, 14 xii 2009, J. Bergsten, N. Jönsson, T. Ranarilalatiana, HJ. Randriamihaja ( MAD09-50 ) (2 NHRS) ; Parc National Tsingy de Bemaraha, 3.4 km 93° E Bekopaka, Tombeau Vazimba , sifted litter, tropical dry forest, elev. 50 m, 19° 8' S, 44° 49' E, 6–10 xi 2001, Fisher, Griswold et al. (BLF 4232) (6 CAS) .

Differential Diagnosis. Differentiated from other species by the combination of a pronotal fascia, very shallow PF2 and PF4 foveae, and the relatively wide pronotal base. Males are also differentiated from others in the group (those having PF2) by the sinuate inner margins of the metatibiae. The aedeagus differs markedly from others in the group.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.40/0.61; head width 0.37; pronotum 0.35/0.50, PA 0.40, PB 0.48; elytra 0.85/0.61.

Dorsum of head with frons and clypeus dark brown to piceous; pronotum with dark brown fascia, diffusely margined, borders light brown to testaceous; elytra brown; legs light brown; maxillary palpi testaceous, distal 0.5 of last palpomere slightly darker.

Head with clypeus very finely sparsely punctate, each puncture with moderately long, very fine decumbent seta. Frons punctures ca. 1–1.5xef, larger and denser near eyes than medially; interstices shining, 0.5–1xpd laterally, 3–5xpd medially. Mentum very sparsely very finely punctulate, shining. Postmentum with microreticulate median depression. Genae raised, shining, without posterior ridge.

Pronotum with lateral margins arcuate, posterior angles nearly right angles; anterior margin straight behind eyes, emarginate in middle; punctures on disc ca. same size as those of frons, interstices shining, 2–3xpd, punctures larger and denser at anterior and posterior; PF1 absent or nearly so; PF2 shallow, oval; PF3 moderately deep; PF4 absent.

Elytra weakly arcuate laterally; summit of posterior declivity at about midlength; lateral explanate margins narrow; serial punctures shallowly impressed, on disc ca. 1xpd largest pronotal punctures. Intervals not raised, shining, ca. 1–1.5xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/1/2/1.5. P1 laminate; median carina sinuate in profile. P2 l/w ca. 2/1, sides slightly converging toward blunt apex, apex raised slightly above metaventral intercoxal process. Plaques moderately wide, tapering and slightly converging anteriorly, basally separated by ca. plaque width, located at sides of shallow median depression. Metaventrite with very short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at slightly arcuate posterior margin ca. 1.5x P2. Protibia arcuate; mesotibia straight. Metatibia widened, widest slightly before midlength, medial margin sinuate and bearing brush of decumbent and recumbent setae. Abdominal apex with moderately large, slightly offcenter asymmetrical notch.

Etymology. Named in reference to the sinuate inner margins of the male metatibiae.

Figures

FIGURE 112. Hydraena sinuatipes, holotype, habitus dorsal, lateral, and ventral.