Patterns of diel activity and behavior of the Bagrada bug were investigated in a series of field and greenhouse experiments at the Yuma Ag Center. Adults of Bagrada bug were monitored by direct observation on broccoli and cauliflower plots throughout consecutive 24-h periods. Our results provide useful information for growers and PCAs that can be applied to their current management programs for Bagrada bug on desert cole crops. Presently, PCAs tend to scout fields and monitor insect pest activity, beginning at dawn. Based on the results in this study, scouting for Bagrada bug in September and October during the coolest part of the morning (0600 – 0900 hours), will likely result in inaccurate low estimates of population density.

Although an action threshold has yet to be established for Bagrada bug, preliminary research suggests that significant stand losses and plant damage can occur when populations exceed one adult per row meter on seedling cole crops. Therefore, monitoring fields and obtaining reliable estimates of Bagrada bug densities are critical for making accurate control decisions; failure to do so may result in unacceptable plant damage or improper insecticide use. Recently developed pest management guidelines for Bagrada bug have incorporated this temperature-density relationship and recommend that PCAs scout fields for Bagrada bug adults when temperatures are near or above 30°C before making management decisions. Furthermore, because growers presently rely on contact foliar insecticide applications for controlling Bagrada bug infestations, sprays applied when the insect are most active on plants during the afternoon and early evening are likely to provide more effective knockdown control than during the early morning hours.

For more information please follow the next link to see the research paper published by the Journal of Economic Entomology by Huang, Reed, Perring and Palumbo.

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To contact Ta-I go to:huang@cals.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.