Isolation and identifcation of entomopathogenic nematodes (Nematoda: Rhabditida) from the Eastern Black Sea region and their biocontrol potential against Melolontha melolontha (Coleoptera: Scarabaeidae) larvae

Abstract

A survey was conducted for entomopathogenic nematodes in various agricultural felds in the Eastern Black Sea region ofTurkey. A total of 77 soil samples were collected from 15 distinct geographic areas during 2010 2011. Seven entomopathogenic nematodeisolates (ZET02, ZET04, ZET09, ZET28, ZET31, ZET35, and ZET76) were detected from the soil samples (9.1% positive) using theGalleria baiting technique. Morphological and molecular characterizations of the isolates were performed for species identifcation.Five isolates were identifed as Heterorhabditis bacteriophora (ZET02, ZET04, ZET09, ZET28, and ZET35) and 2 isolates were identifedas Steinernema feltiae (ZET31 and ZET76). Te efcacy of all isolates was tested on Melolontha melolontha larvae in plastic boxes andpot experiments. Diferent concentrations of nematodes at 0, 500, 1000, or 2000 infective juveniles (IJs)/mL and 2 diferent temperatureregimes (15 and 25 °C) were used. One hundred percent mortality was obtained from the ZET09 and ZET35 isolates at a concentrationof 2000 IJs/mL at 25 °C. Te same isolates also provided 100% protection with 100 IJs/cm 2 in strawberry planted pot experiments.