7. Phelister trigonisternus Marseul, 1889 Figs 4A-D, 5E-G, 6J, K, Map 5

Phelister trigonisternus Marseul, 1889: cxxxix.

Type material.

Lectotype, of undetermined sex, hereby designated: "Amer Sahlberg" / “2772” / "Marseul 14.12.86" / " Phelister trigonisternus " / “Type” / " Phelister trigonisternum [sic] Mars Type" / "Lectotype Phelister trigonisternus Marseul, 1889, M.S.Caterino & A.K.Tishechkin des. 2010"; NHMUK.

Other material.

Brazil: Mato Grosso, Mpio. Cotriguaçu, Fazenda São Nicolau (-9.815, -58.2858), 12/15/10-12/18/10, FIT, F.Z. Vaz-de-Mello & A.F. Oliveira (CEMT, 2ex.); Mato Grosso, Mpio. Cotriguaçu, Fazenda São Nicolau, Matinha (-9.8383, -58.2508), October, 2009, FIT, F.Z. Vaz-de-Mello (CEMT, 3ex.); Pará, Altamira - Marabá: km 18 (-3.15, -52.05), May 1984, FIT (CHND, 8ex.); Pará, Barcarena (-1.5, -48.6167), 6/13/91-6/25/91, FIT (CHND, 4ex.); Pará, Barcarena (-1.5, -48.6167), 12/7/91-12/20/91, FIT, EXO-02915 (CHND, 1ex.); Pará, Belém, Utinga (IPEAN) (-1.45, -48.4333), October, 1984, FIT (CHND, 4ex.); Pará, Belém, Utinga (IPEAN) (-1.45, -48.4333), November 1984, FIT (CHND, 3ex.); Pará, Belém, Utinga (IPEAN) (-1.45, -48.4333), August 1985, FIT (CHND, 3ex.); Pará, Carajás (Serra Norte) (-6.0667, -50.2), May 1985, FIT, EXO-02913 (CHND, 1ex.); Pará, Carajás, Serra Norte (-6.0667, -50.2), 1/22/84-1/27/84, Ss. cad. de Sarigue (CHND, 2ex.); Pará, Tucuruí (-3.75, -49.667), 11/28/85-12/11/85, FIT (CHND, 4ex.); Pará, Tucuruí (-3.75, -49.667), 2/16/89-3/2/89, FIT (CHND, 5ex.); Suriname: Sipaliwini, CI-RAP Surv. Camp 3: Wehepai SE Kwamala (2.3629, -56.6977), 237 m, 9/3/10-9/7/10, FIT, Larsen & Short, EXO-02918 (SEMC, 1ex.)

Diagnostic description.

Length: 2.09-2.36 mm (avg. 2.19 mm); width: 1.81-2.01 mm (avg. 1.89 mm). Phelister trigonisternus is closely related and very similar to the two described above ( P. sparsus & P. pretiosus), differing principally in the following characters: head (frons) slightly broader, distinctly widened above antennal bases; labrum depressed on anterior surface, appearing foveate; lateral submarginal pronotal stria weak to obliterated by larger, more conspicuous lateral pronotal punctures (submarginal stria basically obsolete except for a few connected punctures in some); 5th dorsal stria present in apical 1/3, sutural stria in apical 1/2; striae of prosternal keel weakly united along basal margin; mesometaventral stria reaching basal 1/3 of mesoventrite, lateral metaventral stria nearly reaching middle of metacoxa (longer and displaced laterad from its course in P. sparsus). Male: basal piece ~ 1/3 length of tegmen; tegmen weakly widened at middle, evenly narrowed to base and apex, apex subtruncate; tegmen weakly curved in lateral view, slightly humped near base, weak medioventral process present in basal 1/3; median lobe ~ 2/3 tegmen length, basal apodemes thin.

Remarks.

The impressed labrum of this species is unique among the species in this paper. This species was described only from ‘Amer.[ica]’, so the type locality is very imprecisely known. The closest match we were able to make was with a specimen from Pará, Brazil. It matches the lectotype very well in most characters but differs slightly in that the type lacks a basal fragment of the outer subhumeral stria, has a weaker frontal stria, and has the lateral pronotal punctation slightly sparser.

Distribution.

This species is known from central to northeastern Brazil and Suriname.