<span lang="EN">Genetic Structure and Diversity of the Beet Army<span lang="EN">worm Spodoptera exigua (Hübner) <span lang="EN">(Lepidoptera, Noctuidae) in Iran

Spodoptera exigua is a significant agricultural pest in Iran. In this research, we analyzed a ۷۰۰ base pair DNA fragment of COI to assess the genetic diversity of this harmful pest. In total, ۵۴ specimens were sampled across six Iran’s geographic areas, revealing six distinct haplotypes. The overall populations exhibited low genetic diversity (h= ۰.۴۶۳± ۰.۰۶۸, π= ۰.۰۰۰۹۶±۰.۰۰۰۱۷). No distinct geographic pattern was observed in the haplotype distribution, as indicated by phylogenetic and median-joining network analyses. The median-joining network of Iranian haplotypes, combined with sequences from other global regions, demonstrated lack of geographical clustering, with Hap.۱ as the most prevalent haplotype spanning Iran, Europe, Asia, and Australia, indicative of extensive gene flow and shared evolutionary history. The Fst values for the Iranian populations ranged from -۰.۱۲۲۴۰ to ۰.۰۷۱۸۹, revealing no significant differentiation among the populations. Analysis of molecular variance showed a larger proportion of the variation within rather than between them. After ۱۰۰۰ random permutations, the level of population differentiation was found to be non-significant. The combination of an unimodal mismatch distribution and the non-significant results of Tajima's D (D= ۰.۰۲۰۱۱, P> ۰.۰۵) and Fu's Fs (Fs= ۳.۳۳۳۸۴, P> ۰.۰۵) suggested the beet armyworm may have expanded recently (~۱۰,۰۰۰–۵۰,۰۰۰ years ago) but has returned to a state resembling neutrality without significant selection pressures acting on it. Insights from this population genetic study can aid in crafting targeted approaches for managing this extensively migratory pest.

کلیدواژه ها:

agricultural pest ، COI ، Gene flow ، haplotype distribution ، population genetics