In our last update we published a report that summarized the impact of bagrada bugs on desert cole crops over the past 3 years. That report included a summary of insecticides that PCAs found to be most efficacious against adults on fall crops. As mentioned in that report, the survey results were consistent with efficacy trials that have been conducted in small plot broccoli trials at the Yuma Ag Center over the past three years. These replicated, experimental trials followed a standardized protocol which involved 2-3 applications made during Sep and Oct as broadcast applications delivered at 25 gpa and 40 psi and applied at 5-7 day intervals. Numbers of live bagrada adults and fresh feeding signs on 20 plants per plot were recorded at 1, 3 and 5 days following each application. An example of one of those trials from 2012 is the attached report Evaluation Of Conventional Insecticides For Control Of Bagrada Hilaris On Broccoli, 2012. Since 2010 we have conducted a total of 17 efficacy trials using this experimental approach to evaluate conventional, experimental and organic-approved insecticides against bagrada bug. A summary table for all the products evaluated in these trials can be found in the attached Bagrada Treatment Matrix Table. This summary lists products based on chemistry, the number of trials in which the product was evaluated, the knockdown control at 1 day after application (DAA) and residual control at 5 DAA. Products were categorized as providing Excellent to good control, Fair to marginal control and Poor to no control. Knockdown and residual control was based on both adult counts on plants and fresh feeding signs on new growth following each spray. In general, much like the survey results, the pyrethroids provided the most consistent knockdown and residual control, followed by Venom/Scorpion, Lannate, Lorsban, Assail, Belay and Actara. None of the new experimental chemistry provided consistently Good control, and most of the organically-approved products only provided marginal knockdown. We plan to continue evaluations of new insecticides as they become available for testing.

Remember: “ When in Doubt…… Scout”

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To contact John Palumbo go to: jpalumbo@ag.arizona.edu

For questions or comments on any of the topics please contact Marco Pena at the Yuma Agricultural Center.
College of Agriculture, The University of Arizona, Tucson, AZ.