Ranomafanacrinus Gimmel, 2013

Gimmel, Matthew L., 2013, <strong> Genus-level revision of the family Phalacridae (Coleoptera: Cucujoidea) </ strong>, Zootaxa 3605 (1), pp. 1-147 : 26-27

3. Ranomafanacrinus Gimmel , gen. nov.

( Figs. 37d, e, f )

Type species: Ranomafanacrinus nigrinus Gimmel , here designated.

Type material. See account of R. nigrinus below.

Diagnosis. Easily distinguished by its 4-4-4 tarsi in which the metatarsi are similar in form to the pro- and mesotarsi, the elongate-cylindrical antennal club, the prominent prosternal process, and the mesoventrite with a large hollow cavity for its reception.

Description. Medium-sized, total length 2.4 mm. Pronotal and elytral margins not explanate. Dorsal surface completely black, appendages paler ( Figs. 37d, e, f ). Tibial spur formula apparently 0-1-1, tarsal formula 4-4- 4 in female (male unknown).

Head. Weakly constricted behind eyes. Eyes small; facets flat; not emarginate medially; without posterior emargination; periocular groove present, weak; without setose groove ventrally behind eye. Frontoclypeus not emarginate above antennal insertion; clypeal apex truncate. Antennomere I ovate; antennal club loosely 3- segmented, club weakly asymmetrical, nearly cylindrical; antennomere XI constricted on posterior face. Mandible with apex simple. Maxillary palpomere IV fusiform, stout, inner edge slighly swollen medially. Mentum with sides divergent; labial palpomere III triangular, widest at apex.

Thorax. Pronotum with scattered microsetae; with weakly developed scutellar lobe. Prosternum anteriorly with continuous row of marginal setae, setae normal; procoxal cavity with anterolateral notchlike extension; prosternal process angulate in lateral view, not setose preapically, without spinelike setae at apex. Procoxae moderately separated; protibia without ctenidium on kickface, apical spurs absent. Scutellar shield small, width at base about equivalent to length of eye. Elytron without spectral iridescence; lateral striae suggested, striae with distinct punctures; without transverse strigae; lateral margin without row of sawtooth-like setae. Mesoventral plate not extending posteriorly to metaventrite, forming procoxal rests; mesoventral disc with deep round depression medially for reception of prosternal process; mesanepisternum with transverse carina absent; mesocoxae separated by less than half width of a coxal cavity. Mesotarsomere III not bilobed. Metaventral process extending anteriorly just to halfway point of mesocoxae; metaventral postcoxal lines not separated from mesocoxal cavity margin, but continuous (connected) across base of metaventral process; discrimen short, extending less than halfway to anterior margin of metaventral process. Anterior margin of metacoxa without emargination sublaterally; metacoxal plate with transverse line; metatibial foreface with apical ctenidium straight, perpendicular overall to long axis of tibia; apical spur cylindrical, distinctly shorter than width of tibial apex; metatarsomeres compacted, nearly identical to mesotarsomeres, joint between I and II flexible. Hind wing unstudied.

Abdomen. Abdominal ventrite I without paired lines or calli; spiracles present on segment VII. Female ovipositor weakly sclerotized, palpiform. Male genitalia unknown.

Immature stages. Unknown.

Bionomics. The only known specimen was captured in a Malaise trap in a small clearing in montane rainforest.

Distribution and diversity. Only one species, known from only one specimen collected in Ranomafana National Park, Madagascar.

Included species (1):

Ranomafanacrinus nigrinus Gimmel , sp. nov. (Distribution: Madagascar)

Discussion. Because this genus is known from only one specimen I did not perform a disarticulation. Accordingly, the above description lacks a number of internal and detailed external characters, and the genus was omitted from the phylogenetic analysis.

I have placed this genus within the Phaenocephalus -group because it shares numerous characters with Phaenocephalus and Phalacrinus (compacted tarsi, shape of the antennal club, the triangular terminal labial palpomere, slight narrowing of the head behind eyes, the short metaventral process). However, a number of significant characters are unique to this genus (the form of the mesoventrite, the large prosternal process, the unbroken connection of the metaventral lines across the base of the metaventral process), and it may deserve its own higher taxonomic category. Future investigations into this issue will require fresh material for both DNA work and detailed morphological analysis involving disarticulation.

Etymology. Named after the only known locality (Ranomafana National Park) of the only known specimen, plus the ending - crinus in allusion to its similarity to Phalacrinus . The gender of the name is masculine.

Figures

FIGURE 37. Photographs. Phaenocephalus sp.: (a) dorsal; (b) ventral. Phalacrinus sp.: (c) dorsal. Ranomafanacrinus nigrinus, holotype: (d) dorsal; (e) lateral; (f) ventral. Acylomus aciculatus: (g) dorsal; (h) ventral. Acylomus bicolor: (i) dorsal.