Résumé
Amblyseius swirskii is one of the most important Phytoseiidae mites commercialized worldwide for the control of mites and small insect pests. The study aims to (i) investigate genetic variation among seven populations collected from different locations and crops (cotton, orange) in Turkey and (ii) compare them with commercial populations, based on 12S rRNA and Cytb mitochondrial DNA sequences. The mean genetic distances among the Turkish populations were very low (0.7% for 12S rRNA and 0.9% for Cytb mtDNA), ranging from 0 to 2.8% and 0 to 1.5%, respectively. The two phylogenetic trees show two distinct groups containing the same samples for the two fragments. These clades are separated by a genetic distance of 0.9% and 1.3% for the 12S rRNA and the Cytb mtDNA fragments, respectively. The genetic differences were not explained by location or host plant. However, samples from some populations were exclusively or predominantly included in one of the two clades. When compared with DNA sequences of A. swirskii from commercialized populations, the latter were included in only one clade, as were all samples collected in orange orchards. In cotton fields, as well as on Solanum nigrum, samples from both clades coexist, but in different proportions. These results show a globally low genetic diversity within A. swirskii for the two DNA fragments. The two clades question the existence of a clade derived from commercial releases. However, this result may be related to other factors and additional morphological phenotyping are planned in future studies.