Diamondback moth (DBM) continues to be one of the most damaging pests affecting California brassica production, with growers facing increasing challenges from insecticide resistance and persistent pest pressure.  

To help identify effective management options, Dr. Dylan Beal of UCANR conducted a summer field trial in Salinas Valley for broccoli, evaluating a mix of commercial standards, newly registered products, and emerging insecticide technologies.  

Among the products tested, Incipio® (isocycloseram) was the only treatment that significantly reduced DBM populations compared to the untreated control. Established industry standards such as Radiant® and Proclaim® also showed strong numerical performance, while some biological and reduced-risk products may require longer evaluation periods or different application strategies to demonstrate their full potential. 

These results also highlight the ongoing importance of resistance management and the need for new management tools, research, and practices.  

Researchers are now expanding this work through additional field trials that will evaluate season-long rotational programs, tank-mix strategies, and integrated pest management (IPM) approaches such as biological control, mating disruption, and bug vacuums. Together, these efforts aim to provide growers with a broader toolbox for managing one of the most persistent pests in brassica production.  

For more details, read the full article here: https://ucanr.edu/blog/salinas-valley-agriculture/article/summer2026dbmtrial. 

To contribute to an ongoing survey of Central Coast brassica growers on DBM damage during the first half of 2026 and management tactics in 2025 vs 2026, please click here 

For further information on this trial and the planned fall trials, please reach out to Dylan J. Beal ([email protected])