Plochionocerus pronotalis Asiain, Márquez & Morrone, sp. nov.

Type material (2 specimens). Holotype, male: “ COLOMBIA, Specimen on card / Del Colombia, Cordill Medina, 2000 m, 4.igii / simplicicollis Was. det. Bernh. / Chicago NHMus M. Bernahuer Collection / Holotype Plochionocerus pronotalis Asiain, Márquez & Morrone, 2007 ” (FMNH). Paratype, female: “ Colombia, Cali, Fassl / Medina V.igii. on Colomb. 500 m. / Was. det. Bernh. / idem fourth label / Paratype Plochionocerus pronotalis Asiain, Márquez & Morrone, 2007 ” (FMNH).

Description. Total length 19.5–20.8 mm. Metallic violet-blue.

Head. Subquadrate, 1.22 times as long as wide, 1.35 times wider than pronotum; dorsally convex and ventrally flat (similar to Fig. 11); ventral surface of head with slightly dense, expanded, umbilicate punctures (10–19 in each half of head), arranged in “v” (similar to Fig. 50); first antennomere 1.57 times as long as antennomeres 2+3 combined, second antennomere 0.67 times as long as third antennomere, antennomeres 4– 10 moderately transverse and increasing in size toward antennomere 10, antennomeres 9 as long as antennomere 10, apical antennomere in males moderately longer than wide (1.38 times) and shorter than antennomeres 9+10 combined (0.88 times); mandibles with basal external channel (Fig. 63).

Thorax. Pronotum 1.62 times as long as wide; almost as long as elytra (1.05 times their length); without depressed areas; upper line of pronotal hypomeron almost completely absent. Prosternum moderately transverse (length/width: 0.84).

Aedeagus. Pear-shaped, length 4.33 mm, parameres short (0.24 times as long as median lobe), apical area of median lobe 0.26 times as long as the total length of median lobe, and internal sac moderately visible (Fig. 88).

Variation. The mandibular channel is slightly to clearly developed, but always visible; the upper line of the pronotal hypomeron is almost completely absent in the holotype and slightly visible in the paratype; and the mandibles in males are slightly shorter than in females.

Comparative notes. Easily distinguished from other species by the rectangular or almost subquadrate head, the pronotum that is almost as long as the elytra, the lack of depressed areas on the posterior third of the pronotum, and the poorly developed upper line of the pronotal hypomeron.

Geographical distribution. Colombia.

Etymology. The name refers to the pronotum, which possesses some important diagnostic features.