Insecticide resistance and management in diamondback moth (Plutella xylostella L.): A Review

Abstract

Diamondback moth (Plutella xylostella L.) is one of the most destructive pests of cruciferous crops worldwide and has developed resistance to over 100 insecticidal compounds due to prolonged and indiscriminate use of Insecticides. This review summarizes the major resistance mechanisms in DBM (diamondback moth) broadly categorized into behavioral and physiological adaptations. Behavioral resistance includes avoidance of insecticide-treated surfaces, whereas physiological mechanisms involve reduced cuticular penetration, enhanced metabolic detoxification via cytochrome P450s, glutathione S-transferases (GSTs) and esterases and target-site insensitivity arising from mutations in acetylcholinesterase (AChE), ryanodine receptors (RyRs) and GABA receptors. This review also outlines key resistance detection methods, including toxicological bioassays for LC₅₀ estimation and biochemical assays for detoxification enzyme activity. To mitigate escalating resistance, various Insecticide Resistance Management (IRM) strategies are highlighted, such as window-rotation of insecticides with different modes of action, use of synergists like piperonyl butoxide (PBO) and botanical oils and application of insecticide mixtures for improved efficacy. Emerging molecular approaches including RNA interference (RNAi) and CRISPR/Cas9 genome editing offer promising avenues for restoring susceptibility and reducing selection pressure in field populations. Collectively, these strategies provide a sustainable and integrated framework for managing insecticide resistance in P. xylostella.