Osckayia, Pérez-Flores & Santos-Silva, 2021

Pérez-Flores, Oscar & Santos-Silva, Antonio, 2021, New genus, new species and new records in Lamiinae (Coleoptera, Cerambycidae), Zootaxa 4965 (1), pp. 181-190 : 182-183

Osckayia gen. nov.

http://zoobank.org/ urn:lsid:zoobank.org:act:F23E136B-0B97-454A-9102-0BA8AE0E4D51

Etymology. A combination of names Oscali and Iskay, plus the Latin suffix “us”. Dedicated by the first author to Otto Oscali and Ithan Iskay Pérez Valerio good children and friends, who are enthusiastic entomologists interested on the study of beetles. Masculine gender.

Type species. Osckayia oaxacae sp. nov., here designated.

Description. Male. Body stout. Head not retractile. Eyes not divided, strongly emarginate, area of connection between upper and lower eye lobes very narrow; distance between upper eye lobes greater than three times width of one upper lobe; lower eye lobes about as long as genae. Antennae longer than body; scape without apical cicatrix, not pedunculate-clavate; antennomeres slender, lacking abundant erect setae ventrally; antennomeres III and IV with similar length; antennomere III distinctly longer than scape. Prothorax transverse, with large, conical tubercle on middle of each side. Mesoventral process moderately abruptly elevated anteriorly, longitudinally tuberculate (carinashaped). Metaventrite not shortened. Mesocoxal cavities closed laterally. Elytra not carinate dorsally, granulate basally, lacking erect setae and tufts of setae; humeri rounded, unarmed; outer apex not spiniform. Mesotibiae sulcate dorsally, somewhat notched on base of sulcus.

Remarks. Thomson (1860) established the “ IVe Sous-Groupe. APOMECYNITAE”, which includes “ XVIe Division. APOMECYNITAE VERAE” and “ XVIIe Division. PTEROPLIITAE.” These “divisions” were defined as follows (translated): “APOMECYNITAE VERAE” – Body elongated. Frons short, convex.Antennae far apart, more or less elongated. Prothorax unarmed laterally. Hind legs close to each other, procoxal cavities entire, outwardly angled, tarsal claws divergent; “PTEROPLIITAE” – “Antennae far apart. Protibiae hooked at apex; procoxal cavities entire, outwardly angled.” However, these definitions do not help to separate these two groups.

However, a few years later Thomson (1864) included the type genus of Pteropliini , Pteroplius Lacordaire, 1830 , in “Desmiphoritae” (currently Desmiphorini ), as well as other genera currently allocated in Pteropliini . This classification appears to be very confused and artificial, since Pteropliini has the tarsal claws divergent, while they are divaricate in Desmiphorini . Lacordaire (1872) separated Apomecynini from Pteropliini by the shape of the mesotibiae: dorsally sulcate in the former; not dorsally sulcate in the latter. However, the information about several morphological details sensu Lacordaire is very questionable and, in some cases, entirely false, not only regarding these two tribes, but several other in Lamiinae . For example, in the same group of Pteropliini, Lacordaire (1872) included his “Ataxiides” (type species Ataxia Haldeman, 1847 ). According to Linsley & Chemsak (1985), Ataxiini has “middle tibiae with an external sinus,” which may be interpreted as a sulcus or notch, but indicating that the middle tibia is not simple. In fact, the mesotibiae are somewhat variable in Ataxia .

Breuning (1950) synonymized Niphonini Pascoe, 1864, Emphytoeciini Lacordaire, 1872, and Ataxiini Lacordaire, 1872 with Pteropliini , and defined the tribe as follows (translated): “Scape never very long and narrow. Metaventrite with normal length. Mesocoxal cavities open laterally. Mesotibiae lacking dorsal sulcus and lacking distinct middle tubercle. Tarsal claws divergent.” Linsley & Chemsak (1985) disagreed: “ Breuning (1950) placed the tribe Ataxiini in synonymy with the Pteropliini on the basis of the divergent claws, straight metepisternum, and open middle coxal cavities. The coxal cavities are, by our definition, closed in both groups but other differences between the two tribes make the proposed synonymy unacceptable. The Pteropliini may be characterized by the usually longer antennae, prominent lateral and discal calluses of the pronotum, transversely impressed prosternum, arcuate mesosternal process, anteriorly broad metepisternum, and longer, more slender legs.” Currently, Ataxiini is considered a synonym of Pteropliini (e.g. Monné 2020).

According to Breuning (1971), Apomecynini is characterized as follows (translated): “More or less elongated. Scape rarely with apical cicatrix, very long or the coxal cavities closed [mesocoxal cavities]. Metaventrite sometimes shortened. Coxal cavities open or closed [mesocoxal cavities]. Mesotibia with dorsal sulcus more or less distinct. Tarsal claws divergent. Surface often with erect setae.” Linsley & Chemsak (1985) provided a redescription of Apomecynini , but they made clear that the description was only applicable to North American fauna species: “This tribe has been variously defined. The above description applies only to the single representative occurring in our fauna.”

More recently, Souza et al. (2020) reported that Apomecynini and Pteropliini were not retrieved as monophyletic in any of their analysis. Unfortunately, the type genus of both tribes was not studied. Even so, Pteropliini was included in their “clade M” (based on two non–American genera–one of them Pterolophia Newman, 1842 , apparently, is a mess of many genera considered as subgenera), while Apomecynini (comprised by American species) was included in their “clade H.” Thus, the true morphological differences between American Apomecynini and Pteropliini remain unknown.

The general appearance of Osckayia gen. nov. is somewhat similar to that of Esthlogena Thomson, 1864 , but differs by the elytra lacking long and erect setae (present in Esthlogena ). This would suggest that Osckayia is a Pteropliini . However, Pteroplius acuminatus Audinet-Serville, 1835 , type species of the type genus of Pteropliini , and Saperda alboguttata Mergele, 1802 (= Apomecyna alboguttata ; = A. histrio histrio (Fabricius, 1793)) , type species of the type genus of Apomecynini , have similar mesocoxal cavities: imperfectly closed laterally. The same seems to be true in other American genera currently included in Pteropliini . The mesotibiae in Pteroplius acuminatus are not distinctly sulcate, as in some other genera of American Pteropliini examined by us. In Apomecyna Dejean, 1821 the mesotibiae are distinctly sulcate. However, this feature is very variable in American genera of Apomecynini . For example, they are not distinctly sulcate in Euteleuta Bates, 1885 and Ptericoptus Lacordaire, 1830 , and are distinctly sulcate in Bebelis Thomson, 1864 . Accordingly, we prefer to include it in Apomecynini ( Pteropliini was originally described as part of this tribe), while the eventual true differences between these two tribes are not known.