A new genus, a new species and taxonomic notes in Oxycoleini Martins & Galileo, 2003 (Coleoptera, Cerambycidae, Cerambycinae)

Oxylopsebus Clarke, 2008 is considered as a junior synonym of Oxycoleus Lacordaire, 1868. Equescollum is proposed as a new genus for E. birai sp. nov. from Costa Rica, which is described and illustrated. Key-Words. Costa Rica; New species; Synonymy; Taxonomy.


INTRODUCTION
The genus Oxycoleus Lacordaire, 1868 was originally described in Molorchini Gistel, 1848. Julio (1997) revised Oxycoleus and proposed a key to species of the genus. Later, Martins & Galileo (2003) proposed Oxycoleini to allocate exclusively Oxycoleus, especially due to the modified abdomen of the females. Currently, Oxycoleus is composed of 14 species distributed in the Neotropical region (Monné, 2018).
Herein, we describe and illustrate Equescollum gen. nov. proposed to allocate E. birai sp. nov. and Oxylopsebus Clarke, 2008 is considered a junior synonym of Oxycoleus.
As we can see in the Gounelle's description, the elytral shape of O. gahani does not agree with the typical elytral shape (dehiscent), and this probably led other authors to describe species with non-dehiscent elytra in Oxycoleus.
Later, Melzer (1933) described a variation of the Gounelle species, Tethlimmena Gahani var. tristis (currently O. tristis), and mentioned (translated): "I have a specimen collected by Mr. A. Maller in Mafra (Santa Catarina) which, except for coloring, agrees well with the original description of this species […] Although the difference in color is remarkable, I think nonetheless that it is only a new variety that I call: var. tristis".
Oxylopsebus was described by Clarke (2008) to allocate O. brachypterus Clarke, 2008. According to the author, Oxylopsebus differs specially by the strongly dehiscent elytra and commented: "…apart from the elytra, the differences between Oxylopsebus and Oxycoleus are less obvious…". The other characteristics mentioned are: "…scape is strongly curved (a character shared with Oxycoleus tristis); prosternal process laminiform at base, spatulate at apex and reaching well beyond coxal cavities (not flattened and acuminate, and failing to reach beyond coxal cavities); mesosternal process half as wide as coxae and excavate at apex (not almost as wide as coxae and truncate at apex); legs are very similar in both genera, longer in Oxycoleus, but in Oxylopsebus the hind legs are considerably larger than the others and all the tibiae curved, not just the metati-biae as in Oxycoleus. Finally, the elytra of the Oxycoleini not only almost cover the abdomen, but also opaque, and closely and coarsely punctured throughout (shortened, semi-translucent, and sparsely punctured in Oxylopsebus)." Probably, Clarke (2008) did not have access to other species of the genus, neither photos of the holotypes, and compared its new species only with the species deposited at MZSP (all with non-dehiscent elytra). One evidence of this is the key separating Oxycoleus from Oxylopsebus. In the former, the elytra would be parallel-sided and almost covering the abdomen, while in Oxylopsebus, the elytra would be shorter and acuminate (Clarke, 2008).
We are, therefore, considering the monotypic genus Oxylopsebus as synonymous of Oxycoleus, because the former has the typical elytral shape of Oxycoleus and the other generic characteristics do not separate them. (Clarke, 2008), comb. nov. (Fig. 9 (1885): "A single specimen of this species flew on to Mr. Champion's neck while he was travelling on horseback through the forest of Chorcha. " Neuter gender.
Metafemora and metatibiae with granulated surface, curved at base; femora pedunculate-clavate. Pro-and mesotarsomere I about as long as II+III; metatarsomere I slightly longer than II+III. Thorax. Prothorax as long as wide; sides narrowed anteriorly, with slightly raised tubercle; posterior half with elevated tubercle; posterior fifth narrowed. Pronotum with six tubercles: four elliptical, two anterolateral, deeply marked anteriorly, and two posterolateral (largest), deeply marked at inner side and posteriorly; and two median tubercles, an elongate between anterolateral tubercles, and another elliptical, between lateroposterior tubercles. Pronotal disc with blackish pubescence between tubercles, posterior fifth with whitish pubescence. Prosternum transversely elevated at anterior fifth; central area coarsely punctate, with sparse whitish pubescence on central area and on posterior half. Mesoventrite coarsely, confluently punctate, especially on mesoventral process, with short, sparse, subdecumbent whitish setae (not obscuring integument); mesoventral process width about half diameter of mesocoxal cavity, apex semicircularly notched. Mesanepisternum and mesepimeron with fine, sparse punctures, poorly marked, surface with short sparse subdecumbent whitish setae (not obscuring integument). Metaventrite with sparse punctures, poorly marked, with short moderately abundant subdecumbent whitish setae on blackish area (not obscuring integument); reddish-brown area smooth, almost glabrous with sparse subdecumbent whitish setae, especially on anterior median margin; metathoracic discrimen reaching anterior median margin; metanepisternum with short, moderately abundant, subdecumbent whitish setae interspersed with elongate yellowish setae sparsely distributed. Scutellum length half its width; with whitish pubescence not obscuring integument. Elytra: Dehiscent from posterior half; humeri rounded and slightly projected forward; elytral sides with anterior two-thirds gradually convergent, posterior third coplanar with dorsal area, parallel-sided; posterior dorsal half with well-marked carina; surface coarsely, densely punctate, with sparse whitish pubescence evenly distributed. Legs: Coxae with sparse whitish pubescence; profemora with peduncle about one third clave length, meso-and metafemora with peduncle about half clave length; surface with sparse, erect yellowish setae; apex transversely truncate; pro-and mesotibiae with short, decumbent yellowish setae on inner distal half, remaining areas with sparse, erect, elongate brownish setae; metatibiae strongly arched, coarsely granulated-punctate, with sparse, erect, elongate brownish setae.
Abdomen: With 5 ventrites. Ventrites with sparse, erect yellowish setae, denser laterally. Ventrite I length about 2.3 times largest length of ventrite II, gradually widened posteriorly. Ventrite II gradually widened posteriorly, aligned with ventrite I, posterior margin semicircular, about 0.3 length of I laterally, posterior half with transverse semicircular depression, anterior median margin with row of elongate yellowish setae posteriorly directed; sideward with row (about 1/10 the total width of the ventrite) of thicker, longer setae (about twice median setae), strongly arched toward middle; median posterior margin (2/5 the total width of the ventrite) with row of elongate yellowish conchoidal setae; internal area of depression with abundant, thickened, short yellowish conchoidal setae, evenly distributed (not obscuring integument). Ventrite III with sides gradually convergent posteriorly, forming angle at posterolateral area, about half length of II laterally, posterior margin semicircular (posteriorly divergent); large semicircular area (posteriorly divergent) less sclerotized centrally, with row of elongate brownish setae posteriorly, posteriorly directed at anterior margin of less sclerotized area. Ventrite IV trapezoidal, about 0.7 length of III laterally, slightly notched posteriorly, with elongate brownish setae laterally and on posterior margin, remaining area with sparse white pubescence. Ventrite V strongly notched, about half length of IV laterally, with elongate brownish setae laterally.