Isolation of entomopathogenic nematodes from vicinity of Trabzon, their characterization and investigation of the activity on the melolontha melolontha

In this study, we aimed to survey entomopathogenic nematode from various agricultural regions in the province of Trabzon and its districts, seventy seven soil samples were collected from 15 distinct geographic areas. Out of 77 soil samples collected from the region, seven were positive for EPNs (9,09%). According to the morphological and morphometric studies, it was determined that all of the samples were in Steinernema and Heterorhabditis genus. Their molecular characterization was performed by sequence analysing of ITS regions in 18S-28S nuclear rDNA. The samples were identified as Hetrorhabditis bacteriophora (ZET02, ZET04, ZET09, ZET28 and ZET35) and Steinernema feltiae (ZET31 and ZET76). Among these isolates, S. feltiae and H. bacteriophora are the most frequently distributed species in the region. The mortality rate at 25 °C was greater than 15 °C at the all tests, approximately. The efficacy of all isolates was tested on Melolontha melolontha (Coleoptera: Scarabidea) larvae at different concentrations (500, 1000 and 2000 infective juveniles İJs/ml). The highest mortality rate was obtained as 100% from ZET09 and ZET35 at 25±1 °C. As a result of pot experiment, it was shown that isolates ZET09 and ZET35 have a good potential for controlling the damage of M. melolontha.