Variation in mitochondrial cytochrome c oxidase subunit I gene in Nezara viridula (Hemiptera: Pentatomidae) from Argentina

Here, we examine the genetic diversity in the agricultural pest Nezara viridula (Linnaeus, ) from populations of Argentina using mitochondrial cytochrome c oxidase subunit I (COI) gene sequences. The DNA sequence comparisons of 718 base pairs of the COI gene revealed seven haplotypes. The observed total haplotype diversity (Hd) value was of 0.138, and the nucleotide diversity was of 0.00039 and 0.00135 according to pi and theta(W), respectively. Eight out of the 10 populations analysed, mostly from soya bean crops, only presented the more frequent haplotype, while 2 haplotypes were found in a mixed culture and 6 haplotypes in a peanut culture. Factors such as differential insecticide applications, as well as the surrounding habitat, and the host plant preference could be related to the genetic diversity differences observed among samples of N. viridula. The analysis of genetic diversity in samples collected in crops treated and non-treated with insecticides, as well as in samples collected from different seasons, could help to clarify the role of the factors that led to the pattern of genetic diversity detected in this study. The result of a comparative analysis of COI gene sequences among populations from South America, Africa, Asia and Europe was consistent with the hypothesis of an African origin of N. viridula. On the other hand, the haplotypes of Europe were clustered with haplotypes from South America. In addition, specimens from Madeira (west of Europe) shared ancestry with South America and Europe. It has been suggested that a probable route of colonization of America could have been from Western Europe towards the eastern coasts of South America.