Impact of Diamondback Moth Outbreaks on Arizona Cole Crops in 2016‐17

Abstract

In the 2016–2017 growing season, Arizona cole crop growers experienced severe outbreaks of a resistant diamondback moth (DBM) (Plutella xylostella) population, leading to substantial yield losses and high insecticide use. Originating from infested greenhouse transplants, the outbreak spread to direct-seeded crops and overwhelmed standard management practices. Surveys of growers and pest control advisors (PCAs) revealed extensive insecticide applications, with limited success from commonly used products like pyrethroids and chlorantraniliprole. The study highlights the economic and agronomic impact of the outbreak and the urgent need for resistance management and improved transplant production practices.