Assessment of detoxification enzymes in pyrethroid-resistant Listronotus maculicollis Kirby suggests additional mechanisms

Insecticide resistance is a pressing issue in urban pest management. The annual bluegrass weevil (ABW), Listronotus maculicollis Kirby, is a highly destructive turfgrass pest in northeastern North America. The overuse of pyrethroids has led to resistance in some ABW populations in the northeastern United States. Understanding ABW resistance mechanisms is pivotal for sustaining turf quality and minimizing environmental impact. This study investigated the potential for enzymatic detoxification, a common resistance mechanism in insects, to be the mechanism behind ABW tolerance to pyrethroids. Different ABW populations’ resistance levels to bifenthrin were determined through dose–response Petri dish assays. Cytochrome P450 activity and protein concentrations were measured following bifenthrin exposure. Results indicated golf course-specific effects on enzyme and protein levels but found no direct correlation between these levels and bifenthrin dosage. P450 activity varied among different golf course populations, showing no dependence on bifenthrin dosage. These findings question prior studies suggesting P450 involvement in bifenthrin detoxification in populations of all resistance levels. This study establishes a foundation for comprehending ABW resistance mechanisms and devising effective management strategies. However, further research is needed to investigate additional detoxification enzymes and other resistance mechanisms.