Farmers in the desert regions may be seeing increased bagrada bug pressures during the fall season. The pest can be particularly challenging due to the number of insects that growers can experience with an infestation. University of Arizona Extension Specialist John Palumbo said that monitoring for damage is critical for staying on top of the problem.
“That’s the key,” Palumbo noted. “Look for the fresh feeding damage because it’s highly correlated with the presence of adults in the fields. We’ve done enough research to feel confident that if you see fresh feeding damage and it exceeds about five percent of the plants it’s time to pull the trigger to prevent economic losses.”
Bagrada bug populations have been relatively manageable in Arizona and the California desert over the past few years. Palumbo explained that things could change for this year’s fall crops. Numbers began to build up fairly late and summer crops have sustained populations.
“Some of the weather events we had last spring kind of suggests that we might see some more than we have in the previous four or five [years],” said Palumbo. “Historically over the last ten years bagrada bug typically really starts to build towards the end of September when the humidity breaks and peaks early October.”
The pest is generally most active during the middle of the afternoon; however, they can still be difficult to spot. Growers and Pest Control Advisors will want to be on the lookout for fresh damage.
“It’s pretty rare to get nymphs migrating into the field. It’s generally adults that are coming out of an alfalfa field, a Sudan grass field, Bermuda grass, cotton, what have you. That’s the tough part because they can wreak a lot of havoc in just a short period of time,” Palumbo explained. “Most guys are chemigating preventatively and keeping a key eye out for fresh feeding damage.”