Diamondback Moth on Desert Cole Crops in 2017

Abstract

This report details the impact and management of diamondback moth (DBM), Plutella xylostella, on desert Cole crops during the 2017–2018 season, following a major insecticide-resistant outbreak in 2016. Survey results from growers and pest control advisors (PCAs) across Arizona and California indicate that DBM pressure in 2017 was significantly reduced, with few reports of resistance or crop losses. Field and lab data confirmed that DBM populations in 2017 were susceptible to commonly used insecticides, including diamides. The findings support the hypothesis that 2017 infestations originated from distinct populations introduced via transplants or weather events, rather than persistent local resistance.