Hydraena breviceps, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 29-30

Hydraena breviceps , new species

Figs. 16 (habitus), 19 (aedeagus), 234 (map)

Type Material. Holotype (male): Fianarantsoa, 29 km SSW Ambositra, Ankazomivady, sifted litter (leaf mold, rotten wood), disturbed montane rainforest, elev. 1700 m, 20° 47' S, 47° 10' E, 7 i 1998, B. L. Fisher (1590) ( FMNH). Paratypes: Same data as holotype (199 FMNH).

Differential Diagnosis. Similar in habitus to H. genuvela and H. fortipes . The pronotum is slightly less transverse than in those species, and the clypeus is more distinctly emarginate along the anterior margin. The aedeagus, however, differs markedly from the compared species, being much smaller and not having an extremely elongate distal tube ( Fig. 19).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.81/0.86; head width 0.49; pronotum 0.42/0.68, PA 0.54, PB 0.58; elytra 1.14/0.86.

Dorsum dark brown, frons darkest; legs brown; maxillary palpi light brown to testaceous, distal ½ of last palpomere not darker.

Frons and pronotum densely coarsely punctate. Clypeus finely moderately sparsely punctate; concave laterally, apical margin widely moderately deeply emarginate. Punctures of pronotum slightly larger than those of head, each puncture with short recumbent seta; interstices varying from narrow ridges to ca. 1xpd, very weakly shining. Mentum sparsely finely punctulate and moderately setose, weakly shining; postmentum rugulose, dull. Genae raised, weakly rugulose, dull, with posterior ridge, interrupted in midline.

Pronotum widely arcuate laterally; anterior margin distinctly emarginate behind eyes, very weakly emarginate behind frons; PF1 and PF2 shallow; PF3 and PF4 deep, area between them tumid.

Elytra arcuate laterally; summit of posterior declivity near midlength; lateral explanate margins very wide, margin serrate, very closely so in anterior 0.5, only very slightly more deeply serrate in posterior 0.5, row of punctures at base of explanate margin very large and very deep; serial punctures round, each with minute granule at anterior margin, separated by ca. 1xpd, slightly smaller than largest pronotal punctures. Even numbered intervals 2–10 very weakly raised and granulate, interval six more distinctly raised over posterior declivity. Odd numbered intervals flat, ca. 2xpd, shining. Apices in dorsal aspect separately weakly rounded, in posterior aspect margins do not form angle with one another.

P1 and P2 narrow, subequal in width. P1 median carina sinuate in profile. P2 with sides parallel, apex pointed. Plaques very narrow, slightly wider posteriorly, located at sides of median depression. Metaventrite with very short point on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at slightly arcuate posterior margin ca. 2x P2. Legs short, stout. Male fifth abdominal ventrite very weakly transversely raised. Abdominal apex with large apicomedian notch.

Etymology. Named in reference to the blunt anterior margin of the head.

Figures

FIGURE 16. Hydraena breviceps, holotype, habitus dorsal, lateral, and ventral.

FIGURES 233 – 236. All locality sites for Hydraena, Hydraena (Micromadraena), Limnebius, and Madagaster.