Oxycoleus Lacordaire, 1868

Nascimento, Francisco Eriberto De L. & Santos-Silva, Antonio, 2021, The interesting and complex tribe Oxycoleini (Coleoptera, Cerambycidae): a new genus, new species, and taxonomic notes, Zootaxa 5060 (3), pp. 353-370 : 357-359

Oxycoleus Lacordaire, 1868

Oxycoleus Lacordaire, 1868: 485 .

Remarks. According to Bates (1880) on Oxycoleus : “A curious genus of the Molorchina group, with abbreviated triangular elytra. It is allied to the European and North-American Callimoxys , and is scarcely distinguishable from Merioneda [sic] (Pascoe) of the Malay Archipelago and Malacca. Stenoptrellus (Bates) from the Amazons, published a year after Oxycoleus , is evidently congeneric.” Later, Bates (1885) synonymized Oxycoleus with Merionoeda , and reported: “The structural characters of Merionoeda and Oxycoleus in both sexes offer no essential difference: and united they form a well-marked and most interesting genus, allied to the European and North-American genus Callimus .” Chemsak & Linsley (1974), without explanation, transferred Merionoeda bicolor (Melzer, 1934) , M. culicina (Bates, 1870) , M. gratiosa Bates, 1885 , and M. clavipes ( Lacordaire, 1868) to Oxycoleus . Merionoeda brasiliensis Tippmann, 1953 , Merionoeda carinatipennis Zajciw, 1964 , and Merionoeda ruficollis Zajciw, 1964 were not mentioned. These three species were included in Oxycoleus , also without explanation, by Monné & Giesbert (1992). As the transference of the type species of Oxycoleus ( O. clavipes ) occurred in Chemsak & Linsley (1974), from Merionoeda to Oxycoleus , it must be considered that the revalidation of Oxycoleus occurred in this work.

Lacordaire (1868) separated Oxycoleus from Merionoeda in his key: “b. Antennae filiform or setaceous,” leading to Oxycoleus ; “bb. Antennae fusiform; metatibiae denticulate,” leading to Merionoeda . However, the difference in the antennal shape does not allow separating these genera, even considering only the species included by Lacordaire (1868) in Merionoeda . For example, the antennae in M. acuta Pascoe, 1866 do not differ from those in the type species of Oxycoleus . In fact, at least part of this misconception was made by Pascoe (1858), who described the antennae in Merionoeda Pascoe, 1858 as “short, claviform, the six or seven last joints dilated,” and had included M. indica (Hope, 1831) and M. nigriceps (White, 1855) in the genus; these two species have all antennomeres nearly cylindrical.

Nearly all species Merionoeda (Merionoeda) have distinct spicules on the metatibiae (according to Pascoe (1858), they are “serrated and spurred”), which are absent in the species of Oxycoleus . However, as there are species lacking the spicules on the metatibiae (e.g. M. glabra Yokoi & Niisato, 2012 ), the differentiation between Merionoeda (Merionoeda) and Oxycoleus based on this feature is problematic. The sixth ventrite (sternite VIII) in the species of Oxycoleus is distinctly exposed at the abdominal apex. However, it is also distinctly exposed at least in Merionoeda (Merionoeda) africana aethiopica Adlbauer, 1994 , the only species examined by us. Therefore, it is another feature that does not help in separating Oxycoleus from Merionoeda (Merionoeda) . For the time being, Oxycoleus is maintained as a distinct genus, until a greater number of species of Merionoeda (Merionoeda) are studied. Moreover, it seems evident to us that Merionoeda (including the three subgenera) should be excluded from Stenopterini Gistel, 1848 and included in Oxycoleini Martins & Galileo, 2003 , due to the abdominal setation on the ventrites 2 and 3 of the females.

Oxycoleus differs from Merionoeda (Macromolorchus) Pic, 1922 especially by the absence of the tuft of setae on the metatibiae (present in nearly all species of Merionoeda (Macromolorchus )), and by the absence of a dense tuft of long setae on the ventral surface of the metafemoral club (present in all species of Merionoeda (Macromolorchus) , although, sometimes, not dense). Finally, Oxycoleus differs from Merionoeda (Ocytasia) Pascoe, 1869 by the mesotarsomeres of the males without modifications (mesotarsomeres I and II distinctly projected on the outer side in Merionoeda (Ocytasia )), and meso- and metatarsi with similar appearance (strongly different in Merionoeda (Ocytasia) , in which the mesotarsi are much wider than the metatarsi).

Even with the transference of one species from Oxycoleus to Tethlimmena , and three to Wappesia gen. nov., the genus still includes two groups of species: 1. Elytra strongly narrowed toward apex, which is at least somewhat acute; 2. Elytra not strongly narrowed toward apex, which is rounded. In the group of species with rounded apex, the humeral carina may be complete, from base to apex, as in O. carinatipennis ( Zajciw, 1964) , or present only on posterior half or apically or even absent as in O. laetus Júlio, 1997 . It is possible that there are species of two genera still included in Oxycoleus : one with acute elytral apex; another with rounded elytral apex. However, the position of the humeral carina in O. flavipes ( Figs 25, 30 ), distinctly becoming dorsal after middle, suggests that these two groups of species belong to Oxycoleus .

For complete references on Oxycoleus , see Monné (2021) and Tavakilian & Chevillotte (2021).

Figures

FIGURES 25–31. Oxycoleus flavipes Martins & Galileo, 2006. 25–12) Male from Bolivia (Santa Cruz): 25) Dorsal habitus; 26) Ventral habitus; 27) Head, frontal view; 28) Abdominal apex; 29) Lateral habitus. 30–31) Female from Bolivia (Santa Cruz): 30) Dorsal habitus; 31) Ventral habitus.