Carlos José Einicker Lamas, Silvio Shigueo Nihei, André Mallemont Cunha, Márcia Souto Couri
Florida Entomologist 97 (3), 952-966, (1 September 2014) https://doi.org/10.1653/024.097.0353
KEYWORDS: cladistic biogeography, dispersal-vicariance analysis, DIVA, Nearctic, neotropical, systematics, biogeografía cladística, análisis de dispersion-vicarianza, Neártica, sistemática
A cladistic and biogeographic analysis is presented of Heterostylum Macquart (Diptera: Bombyliidae), a New World bee-fly genus with 14 species. A phylogenetic hypothesis was obtained based on a data matrix with 27 characters, using the cladogram analysis and search program, TNT, and the matrix editing and tree viewing program, WINCLADA. Character states were polarized by tree rooting with the following outgroup taxa: Toxophora aurea Macquart, Apiformyia australis Yeates, Triploechus novus Williston, T. bellus Philippi, and T. heteronevrus Macquart. The monophyly of Heterostylum was well supported, and after successive weighting was applied, 2 major clades were found: a Nearctic clade including H. robustum (Osten Sacken), H. helvolum Hall & Evenhuis, H. deani Painter, H. croceum Painter, and H. engelhardti Painter, and a Neotropical clade with H. haemorrhoicum (Loew), H. rufum (Olivier), H. evenhuisi Cunha & Lamas, H. maculipennis Cunha & Lamas, H. ferrugineum (Fabricius), H. hirsutum (Thunberg), and H. pallipes Bigot. For the biogeographic analysis we derived an area cladogram based on the phylogenetic hypothesis obtained to analyze the distributional pattern and spatial diversification of Heterostylum. The divergence between Nearctic and Neotropical clades is associated with a spatial disjunction along the Mexican Transition Zone, which supports evidence that an ancient Caribbean event was mainly responsible for the diversification of major lineages of Heterostylum. This biogeographic scenario, as well as alternative scenarios, was also analyzed and discussed along with the results obtained from an event-based biogeographical analysis (DIVA).