Insecticidal effect of entomopathogenic nematodes and the cell-free supernatants from their symbiotic bacteria against different larval instars of Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae)

Abstract Background Entomopathogenic nematodes (EPNs) (Steinernematidae and Heterorhabditidae) their symbiotic bacteria are pathogenic for a wide range of insect pests have been used successfully as biological control agent. Although EPNs well studied against many agricultural pests, the efficacy still remains unclear importance. In present study, virulence native EPN isolates cell-free supernatants were tested 3rd 4th larval instars Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae) under laboratory conditions (25 ± 1 °C R.H. 60%). Results The instar larvae more susceptible to infective juveniles (IJs) mortalities over (95%) achieved by all at concentration 100 IJs/cm 2 after 72 hrs exposure. effective highest recorded 42 60% in contact leaf disc bioassays, respectively. Conclusion results indicated that can be an ideal application young stages A. . However, further studies required test effectiveness both field conditions.