The Bagrada bug, Bagrada hilaris, has been major problem in desert cole crops the past two fall growing seasons. In 2010, widespread infestations were reported throughout the desert growing area in September and October where stand losses and yield/quality reductions to broccoli, cauliflower, cabbage and other Brassica crops were considered economically significant in some growing areas. In 2011, Bagrada populations did not appear until early October, but certainly caused crop losses and required control with insecticides. In an attempt to document the impact of these outbreaks on desert production, a survey of growers and PCAs from Yuma and Imperial Valley was recently conducted to estimate the severity of Bagrada bug infestations on direct-seeded and transplanted cole crops during 2010. A summary of the survey results can be found at Impact of the Bagrada Bug on Desert Cole Crops: A Survey of PCA/Growers in 2010 and 2011. In general, the results of surveys in 2010 and 2011 showed that more than 93% of direct-seed cole crop acreage (e.g., broccoli) was treated for Bagrada adult infestations with insecticides compared to transplanted cole crops (e.g., cauliflower) where about 86% of the acreage was reported to be treated. Similarly, estimates showed that direct-seeded cole crops sustained greater stand losses and plant injury from Bagrada feeding than transplanted crops. When averaged over both years, estimated stand losses and plant injury caused by Bagrada bug feeding exceeded 10 % in direct-seeded crops. PCAs also provided information on insecticides that provided effective control through both chemigations and foliar sprays. In general, they reported that products that have contact activity (i.e., Pyrethroids, OP/Carbamates) appeared to provide the most effective control against Bagrada adults on both direct-seeded and transplanted cole crops. Overall, the results of the PCA survey are consistent with results obtained in research trials conducted at the Yuma Agricultural Center last year. In addition, access to the 1080 database showed that insecticide usage on cole crops has nearly doubled since Bagrada outbreaks first occurred in the fall of 2010.

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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.