Pluricosta, Caterino, Michael S. & Tishechkin, Alexey K., 2014

Caterino, Michael S. & Tishechkin, Alexey K., 2014, New genera and species of Neotropical Exosternini (Coleoptera, Histeridae), ZooKeys 381, pp. 11-78 : 23-24

Pluricosta gen. n.

Type species.

Pluricosta onthophiloides sp. n.

Description.

This genus differs from other Exosternini in the following combination of characters: body round, strongly convex, with strong elytral ridges, rufescent, glabrous; frons and epistoma depressed along midline, frontal stria present; labrum wide, shallowly emarginate apically; mandibles with weakly arcuate incisor edges lacking basal teeth; antennal scape slightly wider near base, narrowed apically, with longitudinal carina along inner anterior edge; funicle shorter than scape, weakly widening apically, antennomere 8 short, cupuliform, not disc-like; antennal club slightly elongate oval, largely tomentose, with only indistinct subapical sensory patches; pronotum rather strongly convex, with two gland openings on each side, anterior opening simple, along anterior margin behind eye, posterior opening with secondary annulus, displaced posterad to near middle of disk; prescutellar impression absent; elytra with strong longitudinal ridges, apparently corresponding to alternate interstriae; prosternal keel emarginate at base; prosternal lobe short, apically truncate; mesoventrite narrowly produced at middle; propygidium slightly shorter than pygidium along midline, with gland openings near anterolateral corners; pygidium equilaterally subtriangular, apex rounded, simple; each trochanter with single long seta; femora narrow; protibia rounded apically, lacking marginal teeth, with marginal spines inserted only along apical half of edge; protibial spurs present, reduced; meso- and metatibiae thin, simple, with single longitudinal stria along inner edge, completely lacking teeth or spines along outer margin; all tarsi slightly compressed, with slightly spatulate ventral setae; male not known; female T8 divided; S8 forming a single plate, basal baculi articulated with basolateral corners, convergent, separate at base; S9 not evident, though elongate articulating strap from median apex of S8 is present; T10 not observed; valvifers paddle-shaped, basal paddles just over one-third entire valvifer length; coxites over two-thirds valvifer length, apically tridentate, with lateral teeth rather weak; gonostyle slightly shorter than median tooth, setose; bursa copulatrix membraneous, lacking sclerites, not obviously expanded; spermatheca forming a gradually enlarged, elongate sac, an elongate, slightly kinked spermathecal gland inserted near its midpoint.

Remarks.

This genus is unmistakable in its elevated, longitudinal elytral ridges (Fig. 7). In our recent analysis of Exosternini relationships (Caterino and Tishechkin in review), it is placed as sister to a group containing Mecistostethus and Lacrimorpha , described below.

Etymology.

The name of this genus refers to the series of ridges on the elytra; feminine.