Tracing the origin of the alien pest Cydia pomonella in Algeria through a worldwide comparison of the species’ DNA barcodes

Abstract

DNA barcodes (i.e., gene sequences used as identifiers for species identification) constitute a very useful tool in invasive pest research. Using them, we studied, for the first time, the origin and population structure of the alien Cydia pomonella in Africa, a major apple pest. We sequenced a fragment of the mitochondrial gene Cytochrome c oxidase subunit I (COI) from C. pomonella caterpillars collected in northern Algeria and compared them with DNA barcodes from the rest of the world available at public repositories. The phylogeny built upon that COI database supports the European origin of the species: haplotypes at the base of the phylogeny were registered in this continent. In Algeria, the results suggest that this pest could have been introduced from Europe, with two unique African mutations probably favoured by C. pomonella multivoltinism and large population sizes. Population genetic analyses at three Algerian localities showed neither structure nor founder effects. However, to confirm the underlying process of the observed population patterns, it is necessary to perform analyses using genes with higher mutation rates. Compared to higher resolution markers, mitochondrial DNA barcodes are still a cost‐effective tool for taxonomic determination of unknown specimens and, sometimes, may also allow a preliminary tracing of its origin. This is crucial to detect and stop the spread of invasive pests (i.e., borders). We encourage further studies including functional genes to assess whether any mutations are promoting C. pomonella adaptation to the Northern Africa environment.