Diversification patterns of the grasshopper genus Zoniopoda Stål (Romaleidae, Acridoidea, Orthoptera) in open vegetation biomes of South America

POCCO, MARTINA; GUZMAN, NOELIA V.; PLISCHUK, SANTIAGO; CONFALONIERI V.A.; LANGE,CARLOS; CIGLIANO M. M.

SYSTEMATIC ENTOMOLOGY (PRINT)

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2017

0307-6970

The grasshopper genus Zoniopoda constitutes one of the most numerous genera of Romaleinae from southern South America. Currently represented by 11 valid species included in the Tarsata and Iheringi groups, this genus is widely distributed in open vegetation biomes within the Chacoan subregion, with the major species richness found in Cerrado and Chacoan provinces. In order to confirm the placement within Zoniopoda of a new species found in the south of its distributional range, in hills of central Argentina, here recognized as a highly diverse area for grasshoppers, we performed phylogenetic studies based on morphology and molecular evidence. We also analyzed the relationships of Zoniopoda to the other Romaleinae distributed in southern South America and the biogeographic patterns of diversification of the whole genus. The results of our phylogenetic analyses confirm the inclusion of the new species within Zoniopoda, which was always recovered as a monophyletic group, closely related to the sister taxa Diponthus and Chromacris. Based on the morphological and total evidence analyses, we assigned Zoniopoda crenata sp.n. to the Iheringi group. According to the dispersion-vicariance analysis the ancestor of Zoniopoda was distributed in an area corresponding to the Chacoan and Cerrado provinces. In this area, a vicariant event is suggested to have occurred splitting the ancestral distribution of Zoniopoda resulting in the independent evolution of the clade constituted by the species of the Tarsata group within the Cerrado and the clade comprising the species of the Iheringi group, in Chacoan. Assuming that the origin of the genus may have occurred during Late Pliocene (~3 Mya) based on the results of our molecular clock analysis, the mentioned vicariant event could be explained by the uplift of the Brazilian Plateau and the subsidence of the Chaco as a result of an intense phase of uplift of the Andes. The current wide distribution of the remaining species of both clades may be explained by recent dispersal events to other biogeographic areas.