A cladistic and biogeographic analysis of the species of Agathemera Stal, 1875 (Phasmatodea, Argathemeridae)

DOMÍNGUEZ, MARTHA CECILIA; SAN BLAS, GERMÁN; AGRAIN, FEDERICO ALEJANDRO; DEBANDI, GUILLERMO O.

Tucuman

Congreso; 27th Annual Meeting of the Willi Hennig Society y VIII Reunión Argentina de Cladística y Biogeografía; 2008

Instituto y Fundación Miguel Lillo

Agathemera Stål, 1875 is a genus of the family Agathemeridae (suborder Agathemerodea) that contains eight endemic species from Southern South America. Its species are distributed at both sides of the Andes Mountain range, approximately between parallels 23º and 50º (S). The monophyly of the genus has clearly been established (Camousseight 1995, 2005), however phylogenetic relationships among its species has never been treated in a cladistic analysis. The main objective of this study was to carry out a cladistic analysis based on adult and immature characters belonging to both sexes and a biogeographical analysis to reconstruct the history of the genus. A data matrix of 10 species and 26 morphological characters corresponding to the external morphology and genital structures of both sexes and egg morphology was analyzed. Xeropsis crassicornis and Spicnema chilensis (Phasmatodea: Pseudophasmatidae) were used as outgroups and all known species of the genusA g a th emera were included. The data matrix was analyzed with the program TNT using implicit enumeration, Jacknife and Bremmer were used as support measures. One tree of 51 steps was obtained. This tree supports the monophyly of the genus. Seven characters were found to be synapomorphies of the genus. The species A. elegans and A. mesoauriculae distributed in central Chile are in the base of the cladogram and they are the sister group to both the Argentinian (A. claraziana, A. luteola, A. maculafulgens and A. millepunctata) and the Chilean species (A. grilloideaa nd A. crassa). For the biogeographic analysis we used the program DIVA 1.1, TNT and Mesquite, replacing the name of each taxon by the Ecoregion or Ecoregions that it occupies. The Biogeographic analysis using DIVA 1.1 found 276 equally optimal reconstructions. Two vicariance events were detected: the first with a frequency of 1,870 (at node 14: the separation of Chilean Matorral from South Andean Steppe, Central Andean Steppe and Monte) and the second with a frequency of 0,130 (at node 12: the separation of the Patagonian Steppe from the Valdivian Forest and Chilean Matorral). The most frequents dispersions took place between the Chilean Matorral and the Valdivian Forest (F=1.371) and between the Valdivian Forest and the Chilean Matorral (F=1.313) in the opposite direction.