Compared to last year, Bagrada bug adult numbers have been relatively light on early broccoli plantings, and cauliflower/cabbage transplanted fields in the Yuma and Dome Valley. Furthermore, over the course of the summer, there have been very few reports of adults found in cotton, alfalfa, sudangrass and other seasonal crops relative to last summer. Does this suggest that Bagrada numbers will continue to be light once we get into September and acreage begins to increase. It's possible, but I wouldn't bet on it just yet. Remember, it wasn't until around mid-September last year when it seemed like the clouds opened up and Bagrada bugs dropped from the sky. PCAs and growers should not become complacent just because they aren't finding any Bagrada yet. Rather, it would be wise to assume they will eventually show up in some intensity, and you should prepare for them accordingly. Preliminary research conducted over the past year suggests that direct-seeded and transplanted crops are most susceptible to Bagrada bug infestations during stand establishment. Research to date also suggests that control of heavy Bagrada infestations with insecticides is the most economically viable option to protecting stands and preventing significant yield losses. This includes chemigation with pyrethroids, and using contact insecticides (pyrethroids, Lannate, Lorsban) once plants emerge and pipe is pulled. After stands are established and plant size increases up to the 3-4 leaf stage, or on growing transplants, PCAs may consider alternating to dinotefuron (Venom/Scorpion) for protecting plants from Bagrada feeding. This neonicotinoid will also provide knockdown of adult whiteflies and nymphs. More information on Bagrada bug control can be found in these research reports conducted in a 2010 field trial and in a 2011 greenhouse trial.

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.