Megaphasma denticrus ( Stål, 1875 )

Ghirotto, Victor Morais, Crispino, Edgar Blois, Engelking, Phillip Watzke, Neves, Pedro Alvaro Barbosa Aguiar, Góis, Júlia de & Chiquetto-Machado, Pedro Ivo, 2022, Arumatia, a new genus of Diapheromerinae stick insects (Insecta, Phasmatodea) from Brazil, with the description of five new species and a reassessment of species misplaced in Australian genera, European Journal of Taxonomy 827 (827), pp. 1-85 : 78-79

Megaphasma denticrus ( Stål, 1875)

Fig. 54

Diapheromera denticrus Stål, 1875: 73 .

Diapheromera armata Piza, 1973: 183 . Syn. nov.

Diapheromera denticrus – see Brock et al. 2022 for an extensive citation list.

Megaphasma dentricus [sic] – Caudell 1903: 572 (misspelling of “ denticrus ”).

Megaphasma denticrus – Rehn 1903: 329. (see Brock et al. 2022 for an extensive citation list)

Remarks

While analysing specimens at MELQ, the authors came across the holotype of Diapheromera armata Piza, 1973 ( Fig. 54 ) which was described based on that male, purportedly collected in the municipality of Lavras, state of Minas Gerais, Brazil. Piza, following traditional taxonomic practices at his time, usually considered slight phenotypic variations as enough evidence to propose a new species (see ChamorroRengifo & Braun 2010 and Crispino et al. 2020). Piza (1973) stated that a few differences mainly in body proportions separated D. armata from Megaphasma denticrus ( Stål, 1875) . His species, however, matches the morphology of M. denticrus described in the literature and observed in photographs of type material and additional specimens ( Caudell 1903; Brock et al. 2022), so it is here synonymized under Megaphasma denticrus ( Stål, 1875) . Phasmids belonging to Megaphasma and related genera occur only in North America. Therefore, we do not consider this doubtful record of M. denticrus from Brazil to be valid nor the lineage to have representatives native or introduced to South America. This record could be equivocal and explained by a simple mislabelling or, more unlikely, be explained by an actual event of introduction which is until now unconfirmed and lacks further evidence.

At least two other exotic phasmids were described as Brazilian species by Piza (1938): Dilophocephalus paradiacanthoides Piza, 1938 and Dixippus brasiliensis Piza, 1938 , both of which were later synonymized by Bragg (2001) under other names. The holotype of at least one of these species came from the zoological collection of the Museu Paulista which preceded the creation of the MZUSP ( Grola 2014) and went through several rearrangements and loss of information ( Chamorro-Rengifo & Braun 2010). The same could be true for the holotype of D. armata , leading to a mislabelling of the specimen.

Figures

Fig. 54. Holotype of Diapheromera armata Piza, 1973 at MELQ and accompanying labels. Note that the specific epithet was written as armigera on one of the labels but later corrected by pencil to the published name. Scale bar: 10 mm.