Megalocraerus madrededios, Caterino, Michael S. & Tishechkin, Alexey K., 2016

Caterino, Michael S. & Tishechkin, Alexey K., 2016, A revision of Megalocraerus Lewis, 1902 (Coleoptera, Histeridae: Exosternini), ZooKeys 557, pp. 59-78 : 71-73

Taxon classification Animalia Coleoptera Histeridae

Megalocraerus madrededios sp. n. Figs 6 E–F, 7A, 8

Type material.

Holotype male: PERU: Madre de Dios: Pantiacolla Lodge, Alto Madre de Dios R., 12°39.3'S, 71°13.9'W, 420 m, 14-19.xi.2007, FIT, D. Brzoska (SEMC0874296); Paratype female: same data as type (SEMC0872118); SEMC.

Diagnosis.

The body shape of this species is distinct, being broader and less elongate, and slightly more depressed than any of the others. Additionally the 4th stria meeting the basal sutural arch is shared only with Megalocraerus chico (above).

Description.

Size: Length 3.1-3.3 mm; width 2.3-2.4 mm; Body: broad, subparallel-sided, slightly elongate, moderately depressed; castaneous to slightly rufescent; the elytral bases, pronotum, and venter tending to be slightly lighter than the apical elytral two-thirds. Head: Frons finely and doubly punctate, with medium punctures separated by slightly more than their diameters against fine ground punctation, decreasing in size but slightly increasing in density anteromediad; frontal stria present along inner margins of eyes, bent inward above antennal insertions, broadly interrupted across epistoma; supraorbital stria absent; epistoma depressed, narrowing anterad; labrum minutely punctate; mandibles each with inner marginal tooth. Pronotum: Pronotal sides weakly rounded, slightly narrowed anterad, marginal stria complete, lateral stria absent, anterior marginal stria slightly fragmented; pronotal disk with small secondary punctures sparse basomedially, increasing in density toward front and sides, with fine ground punctation more or less uniform. Elytra: Two complete epipleural stria present; subhumeral striae absent; dorsal striae 1-4 complete, 4th meeting basal arch of sutural stria, 5th stria obsolete near base; bases of dorsal striae extending mediad along basal elytral margin, but not meeting base of next stria; elytral disks with conspicuous ground punctation throughout, and increasingly dense secondary punctation toward apices. Prosternum: Prosternal lobe evenly, broadly rounded, complete to sides, with marginal stria obsolete at sides; prosternal keel with two complete carinal striae converging anteriorly. Mesoventrite: Anterior mesoventral margin evenly emarginate, with complete, marginal stria; mesometaventral stria absent; disk with only fine ground punctation. Metaventrite: Metaventral disk impunctate at middle, with few fine punctures in front of metacoxae, lateral metaventral stria present, extending toward outer corner of metacoxa, slightly obsolete apically; postmesocoxal stria very short. Abdomen: Abdominal ventrites finely punctate at middle, slightly more coarsely at sides; propygidium strongly transverse, about four times as wide as long, coarsely punctate, with punctures separated by slightly less than their diameters, a little denser toward sides; pygidium similarly coarsely punctate at base, punctures becoming finer, but also denser toward apex. Male: 8th tergite with deep basal emargination, ventrobasal processes nearly meeting, dorsally with fine, narrow median emargination; halves of 8th sternite slightly separated along midline, apicomedial processes broadly lobate; 9th tergite with acute, slightly recurved apices, ventrally with uniquely denticulate basal apodeme; spiculum gastrale (S9) broad in basal third, abruptly narrowed, broadening gradually toward head, apex broadly emarginate; 10th tergite entire but weakly desclerotized along much of midline; aedeagus flattened throughout, sides weakly rounded, widest just apicad midpoint, apices meeting; median lobe slightly more than one-half tegmen length.

Remarks.

This species is named for the rich region of Peru in which it is found. This species was included in the phylogenetic analysis of Caterino and Tishechkin (2015) as ' Megalocraerus 1'.