Genetic diversity of Steinernema feltiae Filipjev, 1934 (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora Poinar, 1976 (Rhabditida: Heterorhabditidae) in potato production areas of Türkiye 1

Entomopathogenic nematodes (EPNs) are one of the most important biological control agents and have proved their biocontrol success against a variety of insect pests. However, limited knowledge exists regarding the genetic structure of various species and populations of EPNs. Thus, this study was conducted to isolate and elucidate the EPN's phylogenetic diversity sourced from potato ( Solanum tuberosum L.) (Solanales: Solanaceae) crops in 2020 at Bolu Abant Izzet Baysal University. Through ribosomal DNA sequencing, we investigated genetic variability within and among isolates of Steinernema and Heterorhabditis species. Widespread sampling across Afyonkarahisar, Bolu, & Idot;zmir, Sivas, Ni & gbreve;de, Kayseri, and Konya provinces, covering a total area of 795 hectares, led to the recovery of two EPN isolates, constituting 10% of the samples. Molecular characterization involved ribosomal DNA sequencing, which, upon integration with sequences from 41 populations, confirmed the identification of Steinernema feltiae Filipjev, 1934 (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora Poinar, 1976 (Rhabditida: Heterorhabditidae) , displaying monophyly in most Steinernema and Heterorhabditis clades, respectively. This survey emphasizes the common occurrence of these EPNs in key potatogrowing areas in T & uuml;rkiye, highlighting their biocontrol potential against arthropod pests of agricultural importance.