Genetic structure and diversity of the Diachasmimorpha longicaudata species complex in Thailand: SSCP analysis of mitochondrial 16S rDNA and COI DNA sequences

Genetic variation among 20 populations of Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) in Thailand was investigated using single strand conformation polymorphism (SSCP) analysis of mitochondrial DNA sequences. From a total 641 individual parasitoids, seven distinct haplotypes containing a total of 32 polymorphic sites were observed from cytochrome oxidase subunit I (COI) sequences along with five distinct haplotypes containing a total 16 polymorphic sites from 16S rDNA sequences. Values obtained through pairwise FST comparisons and analysis of molecular variance (AMOVA) indicated significant genetic differentiation among D. longicaudata populations in Thailand. Congruent relationships showing separation of these populations into three groups were obtained from Neighbor joining and Bayesian phylogenetic tree analyses along with the use of haplotype networks. This SSCP analysis of populations of the D. longicaudata species complex is the first report using molecular population genetic methods to analyze the structure of this parasitoid species in Thailand. This may provide useful information for release of parasitoid strains to maximize their benefit in biological control programs.