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Inferring native range and invasion scenarios with mitochondrial DNA: The case of T. solanivora successive north-south step-wise introductions across Central and South America

Abstract:

Tecia solanivora (Lepidoptera: Gelechiidae) is an invasive species that attacks the tubers of the potato Solanum tuberosum. It is considered a serious pest of potato crops and stocks in all countries where it occurs. In the present study, we sequenced 541 individuals sampled across the T. solanivora distribution range, using the mitochondrial DNA marker Cytochrome b (Cytb) to delimit the area of species origin. We also analyzed the genetic structure of T. solanivora in its putative area of origin and described differences in haplotype diversity between samples from different geographic origins affected by the invasion. We observed a gap in the level of genetic diversity between Guatemalan samples (h between 0. 77 and 0. 97) and those from Costa-Rica, Venezuela, Colombia, Ecuador and the Canary Islands (h between 0 and 0. 56). The number of haplotypes has decreased over the colonization process, ending with the observation of a single haplotype in Colombia, Ecuador and the Canary Islands. Consequently, the invasion of South American countries by T. solanivora is likely to have had a front-like step-wise progression, where the most recently invaded country becomes the source of subsequent invasion. © 2011 Springer Science+Business Media B.V.