Effect of Insecticides on Generative Potential of Entomopathogenic Nematode, Steinernema abbasi PN-1 in Spodoptera litura Fabricius

Abstract

This study aimed to evaluate the effects of different insecticides at varying concentrations on the progeny production of the entomopathogenic nematode Steinernema abbasi PN-1 in Spodoptera litura larvae, with a focus on determining the insecticides' compatibility with biological control agents. S. litura larvae were treated with a mixture of S. abbasi PN-1 and insecticides (fipronil, emamectin benzoate, cyantraniliprole, indoxacarb, and chlorantraniliprole) at three different concentrations (lower, medium, and higher). Progeny production of S. abbasi PN-1 was assessed and compared across treatments, with control groups consisting of larvae treated with S. abbasi PN-1 alone. The study found that progeny production was significantly influenced by the type and concentration of insecticides. Fipronil exhibited the least negative impact on progeny production across all concentrations, followed by emamectin benzoate, cyantraniliprole, indoxacarb, and chlorantraniliprole, with the latter showing the most significant inhibitory effects. Higher concentrations of insecticides resulted in a greater reduction in progeny production, indicating a dose-dependent relationship. The results suggest that certain insecticides, particularly at higher concentrations, can negatively affect the progeny production of S. abbasi PN-1, potentially compromising the effectiveness of EPNs in integrated pest management (IPM) programs. The study highlights the importance of selecting compatible insecticides and their appropriate concentrations to enhance the success of biological control strategies involving EPNs.