Cocconotus (Trachymetopion), Braun & Maehr, 2008

Braun, Holger & Maehr, Michael D., 2008, Nomenclatoral changes for some Pseudophyllinae (Orthoptera, Tettigoniidae), Zootaxa 1781 (1), pp. 67-68 : 67-68

Subgenus Trachymetopion nom. nov.

Trachymetopon Beier, 1960

This subgenus under Cocconotus was erected for two species from Central America. The name is preoccupied by Trachymetopon Aldinger 1951 in Hennig (N. Jahrb. f. Geol. Pal., Abh. 94, 67), described as a monotypic genus of fossil coelacanth and having a confusing nomenclatural history. Trachymetopon liassicum was originally used by Hennig in 1939 citing a manuscript by Aldinger and prior to the genus being described. Unfortunately, both Aldinger and his manuscript were lost in the war. In 1951, Hennig provided a complete description while clearly stating that the species formed the basis of a distinct genus and that both genus and species should be attributed to Aldinger. Although different authordate combinations are found in the literature, all have priority over the katydid subgenus described by Beier in 1960.

The name is formed from the Greek words for rough (trachys) and forehead (metopon) and in the katydid it is apparently referring to the diagnostic dense and coarse punctation of the frons. Since the Trachymetopon fossil is at least 1.64 m long and the katydids only 32 mm, the new name is the diminutive of the old one.

The two species originally described by Brunner von Wattenwyl (1895) are very similar. Bliastes lineatifrons is described from a subadult male, Bliastes scabrifrons from an adult male. Photographs of both holotypes are available at Orthoptera Species File Online (Eades & Otte). Beier (1960) already suspected lineatifrons to be the nymph of scabri- frons. He must have inspected both specimens which are in the Natural History Museum in Vienna, as is evident from his diagnoses which are more detailed than Brunner von Wattenwyl’s. The major and eponymous difference between the two is the dark facial pattern. The black on the frons is much broader in scabrifrons and only developed as a fairly narrow vertical line in lineatifrons . The former species also has black stripes on the genae which are lighter brown in the latter. Dark markings on the pronotum and ear region in scabrifrons are also paler or absent in lineatifrons . But coloration can change considerably at the final moult in some Pseudophyllinae (H. Braun, pers. obs.), of which Beier, apparently working exclusively with museum specimens, was probably not aware.

Thus the two specimens indeed should be condsidered adult and nymph of the same species. The terminal spine of the cerci seems to be slightly more incurved in scabrifrons compared to lineatifrons , but according to Beier’s diagnosis cerci and subgenital plate are the same. In Brunner von Wattenwyl’s original description Bliastes scabrifrons precedes Bliastes lineatifrons in the key (p. 182) as well as at the species accounts (p. 187), and the former was also designated type species of the subgenus by Beier. So the latter will become a synonym: Bliastes lineatifrons syn. nov.

Included species: Cocconotus (Trachymetopion) scabrifrons comb. nov.