A phylogeographic study of Ronderosia bergi (Orthoptera: Acrididae) morphotypes

ALBERGHINIA, J.; CIGLIANO, M. M.; CASTILLO, E.; MARTI, D.A.; LANGE, C.A.; CONFALONIERI, V.A.

Antalya, Turquía

Congreso; 10th International Congress of Orthopterology; 2009

The Orthopterists´Society

Ronderosia bergi is one of the most widely distributed species of the tribe Dichroplini. It is found in Bolivia, Paraguay and Argentina, showing high variability in many phenotypic characters such as colour pattern, body size, and length of wings. The colour patterns had received different specific names (Dichroplus distinguendus, D. brasiliensis, D. bicolor). These were later considered as morphotypes of Ronderosia bergi by Cigliano (1997) because no differences in male genitalia and no morphological discontinuities were found among them to warrant separate specific status. However, the fact that viable hybrids were produced from laboratory crosses between individuals of different phenotypes and one mating type but not for the reciprocal cross raised questions about possible incipient reproductive isolation barriers. The aim of this study is to determine, through a phylogeographic study of a mitochondrial gene (cytochrome oxidase I), whether individuals of R. bergii belonging to the same morphotype are grouped within reciprocally monophyletic clades. Specimens with different morphotypes collected from several localities in Argentina, Bolivia and Paraguay were included in the analysis. Atrachelacris grammineus, Ronderosia malloii and R. forcipatus were used as outgroups. Phylogenetic analysis using Maximum Parsimony criteria  showed R. malloi as the most basal group within the genus and R. forcipatus as the sister species of the R. bergi complex. Within this latter species, individuals were not grouped either by morphology or by geographical proximity, thus indicating that morphological discontinuities do not affect the biological species status.