Madagaster bergsteni, Perkins, 2017

Perkins, Philip D., 2017, Hydraenidae of Madagascar (Insecta: Coleoptera), Zootaxa 4342 (1), pp. 1-264 : 187

Madagaster bergsteni , new species

Figs. 179 (habitus), 181 (aedeagus), 301 (map)

Type Material. Holotype (male): Antananarivo, 18.8704S 47.6708E Analamanga, Anjomara mountain next to Ambato- lampikely village, RN2, hygropetric rock, elev. 1470 m, 24 xi 2014, J. Bergsten, R. Bukontaite, J.H. Randriamihaja, T. Ranarilalatiana & S. Holmgren ( MAD 14-79) ( NHRS). Paratypes: Same data as holotype (526 NHRS); one male " MNCN IBE AN333 DNA specimen".

Differential Diagnosis. Similar in habitus to M. procarina and M. barbata ( Figs. 179, 180, 183 ). Differentiated from both species by the more transverse pronotum (W/L ca. 1.69) and, in males, by the dense and long setae on the mentum, the elevated and setose median area of the fifth abdominal ventrite, and the metatibiae, which are slightly arcuate away from the midline. The pronotal foveae are shallower than in the compared species. The very complex male genitalia of the three species share a hook-shaped process on the ventral surface of the main piece, but the parameres and processes of the distal part of the main piece differ markedly ( Figs. 181, 182, 185).

Description. Size (holotype, mm, length/width): body (length to elytral apices) 2.29/1.06, head 0.59/0.39, pronotum 0.52/0.88, elytra 1.41/1.06. Dorsum and venter black, legs dark brown, ocelli light brown to testaceous. Entire dorsum dull, with very small, closely spaced tubercles, each with a short recumbent seta. Labrum bilobed, anterior margin slightly reflexed, sparsely granulate and with sparse small setae except with longer setae along anterior margin. Labrum originating at anterior, slightly overhanging, margin of clypeus. Labroclypeal suture moderately deep. Short, deep sulcus in front of each ocellus. Frons with deep concavity between ocelli. Maxillary palpi slightly shorter than antenna. Antenna with last antennomere much shorter than penultimate.

Pronotum with two narrowly separated midlongitudinal fovea, anterior ca. twice as long as posterior; each side with two admedian and two sublateral foveae; transverse fovea along base, on each side of posterior midlongitudinal fovea; lateral margin rounded.

Elytral suture slightly raised in posterior. Each elytron with four very weakly raised unilinear rows of granules; first row (from suture) slightly curved in ca. middle ½ of length. Areas between unilinear rows of granules with four or five irregular rows of granules. Elytral apices truncate.

Mentum and postmentum (males) punctate and with dense, long pubescence; Genae micropunctulate, dull, concave behind cardo, posterior margin gradual, not carinate. Genae at posterior with transverse arcuate carinate ridge. Subocular groove for antenna moderately deep. Posterior margin of eye not carinate.

Prosternal intercoxal process with raised tip. Mesoventrite without tubercle on intercoxal process. Metaventrite with very short and very dense vestiture, including in median depression ( Fig. 179). First four abdominal ventrites and anterior 1/3 of fifth with hydrofuge pubescence; setae much sparser, non-hydrofuge, on other ventrites. Fifth ventrite of males with large tumid prominence on posterior ½ in midline, tumidity concave behind and with long golden setae in concavity.

Pro- and mesotibiae straight, stout. All tibiae apically with small cluster of moderately long shining setae. Metafemur markedly arcuate in basal 1/3. Metatibia slightly arcuate, toward midline. Mesocoxae (male) with ventral surface slightly flattened.

Abdominal ventrites five and six enlarged in both sexes, in male combined lengths of two to four equal ca. one-half combined lengths of five and six. Seventh ventrite (male) asymmetrical, with concavity on each side of raised median area.

Female smaller than male (ca. 2.00–2.24).

Etymology. Named in honor of Johannes Bergsten, in recognition of his expert leadership in the Madagascar aquatic beetle survey project.

Figures

FIGURE 183. Madagaster barbata, holotype, frontal view, habitus dorsal, lateral, and ventral.