The Arizona Vegetable Integrated Pest Management Update from the University of Arizona (UA) Cooperative Extension in Yuma, Ariz. released Aug. 21, 2013.

Bagrada bug management on desert cole crops

By John Palumbo, UA research scientist and Extension specialist

With the fall produce season quickly approaching, now is a good time to think about Bagrada bugs.

It has been four years since this invasive species first showed up in the low desert. It has clearly found a home on local cole crops. Last year, populations were higher during the fall than seen to date.

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Over this summer, there were reports of Bagrada bug adults found in alfalfa seed, sudangrass and weeds. The bug was found in the Yuma Valley as recently as this week on broccoli seedlings.

What should a pest control adviser expect for this season? I don’t know for sure, but do not become complacent just because Bagrada is not found on the first sets. Assume the bug will eventually show up in some intensity on some acreage. Prepare for them accordingly.

Monitoring for Bagrada at stand establishment should focus on fresh-feeding signs on new plant tissue, and adults later in the day when the bug is most active.

Research and anecdotal observations in fields conducted over the last two years suggests that direct-seeded and transplanted crops are most susceptible to Bagrada bug infestations during stand establishment (cotyledon to the 4-leaf stage).

Results suggest that it does not take a large number of Bagrada adults to cause significant stand losses, and-or crop injury. If fresh feeding signs and-or adults are found in young stands then control should be initiated.

This can include chemigation with pyrethroids, and using contact insecticides (pyrethroids, Lannate, and Lorsban) once stands are lined out and pipe is pulled.

After stands are established and plant size increases up to the 1-2 leaf stage, or on tagged transplants, consider alternating to dinotefuron (Venom/Scorpion) to protect plants from Bagrada feeding. This neonicotinoid will also provide knockdown of adult whiteflies and nymphs.

More information on Bagrada bug management on fall cole crops can be found in these Veg Update briefs:Bagrada Bug Management Tips for the Low Desert and Knockdown and Residual Control of Bagrada Bug with Foliar Insecticides in Broccoli: 2013 Efficacy Report.

Listen to John's Update.

“Remember, when in doubt - scout.”

Contact Palumbo: (928) 782-3836 or jpalumbo@ag.arizona.edu.