Pyxister labralis, 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 : 30-31

Pyxister labralis sp. n. Figs 9 B–D, Map 2

Type locality.

BRAZIL: Rio de Janeiro, Sans Souci [22.2833°S, 42.5206°W].

Type material.

Holotype female: "Brasil, Rio de Janeiro, Nova Friburgo, Sans Souci, 9-15/XI/2009, E. Grossi (leg.)" / “Interceptação de vôo (FIT)" / "Caterino/Tishechkin Exosternini Voucher EXO-00749" (UFPR).

Diagnostic description.

Length: 2.4 mm, width: 1.7 mm; as for generic description, with the following specific characters: frons strongly transversely produced along anterior margin, depressed along midline basad anterior ridge, with antennal insertions deeply incised, frontal stria present only along inner margins of eyes, frontal disk impunctate; frontoclypeal suture not evident; epistoma recessed below frontal margin; labrum very strongly swollen, produced anterad; pronotal sides straight, parallel; marginal pronotal stria interrupted behind eyes, submarginal pronotal stria absent; pronotum very weakly tuberculate at posteromedian gland openings, disk with small secondary punctures almost throughout, absent only mediobasally, separated by approximately their diameters; elytral epipleuron with single, complete epipleural stria rather distant from lateral margin, outer subhumeral stria more or less complete but interrupted near middle and slightly abbreviated at base, inner subhumeral stria absent, 1st-4th dorsal striae complete, 5th stria obsolete in basal half, sutural stria complete, sutural intervals weakly depressed; mesoventrite with marginal stria distinctly interrupted; meso- and metatibiae rather slender, no more than twice as wide apically than basally, finely spinose; propygidium and pygidium completely coarsely reticulopunctate.

Remarks.

This species is easy to distinguish from its only congener by the unique shape of the frons and especially the labrum (Fig. 9D), both being strongly produced. In addition, Pyxister labralis lacks a submarginal pronotal stria, has the 1st dorsal elytral stria entire, and has the propygidium and pygidium densely reticulopunctate (Fig. 9F).

Etymology.

This species’ name refers to its very distinctive, strongly convex labrum.