Genetic and morphological features of some Turkish populations of Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae)

Amblyseius swirskii is one of the most important phytoseiid mites commercialized worldwide for controlling pest mites and small insect pests. The study aims to investigate morphological and genetic variation among seven populations collected from different locations and plant species (cotton, orange) in Türkiye. The DNA sequences (12S rRNA and Cytb mitochondrial DNA markers) were also compared with those of commercial populations. The average genetic distance among the Turkish populations was quite 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 phylogenetic trees show two distinct groups, separated by genetic distances 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, specimens from some populations were exclusively or predominantly included in one of the two clades, and commercialized specimens of A. swirskii only included in one clade, along with specimens collected in orange orchards. Specimens from cotton fields and Solanum nigrum, were found in both clades, but in different proportions. Results show a globally low genetic diversity within A. swirskii for the two DNA fragments. The existence of two clades raises questions about the presence of a clade derived from commercial releases. However, this result may be related to other factors. Morphological analyses demonstrated substantial variability among the populations, except for the population sampled from orange in Adana Kozan. Despite this, the morphological and molecular results are relatively consistent.