Mitochondrial genetic diversity of the invasive drosophilid Zaprionus indianus (Diptera: Drosophilidae) in South America

Abstract

Zaprionus indianus was first reported in South America in 1999 and it has rapidly colonised most of the continent since. Previous studies established Brazil as the sole entry point into the continent and the source of its expansion northward, but dispersal to the southern limit of its distribution in South America has not been studied so far. In the present work we extracted DNA of 127 individuals collected in north-eastern Argentina (South America) and amplified the COII mitochondrial gene in order to describe the mitochondrial genetic diversity and estimate the number of independent introductions of this species into this area. Our results suggest there have been 2-6 independent introductions of Z. indianus in north-eastern Argentina, while the diversity estimates are consistent with a recent invasion. In addition, by comparison with available sequences from other locations we can state that the invasive haplotypes present in Argentina are shared with those found in Brazilian populations and are phylogenetically closer to haplotypes from Africa than those found in India. This places Brazil as the sole recipient of the invasion to the American continent and its subsequent dispersion southwards.