In a field setting, plant damage by the Bagrada bug likely occurs at a slower rate.

When the Bagrada bug first appeared three years ago, farmers, PCAs, Palumbo, and others tried to quickly determine which currently registered insecticides could provide the best pest control.

Palumbo has conducted numerous field and greenhouse trials to investigate the effectiveness of various insecticides on Bagrada bugs. One YAC trial last year focused on various soil-applied neonicitinoid insecticides which target the insect’s central nervous system. The ‘neonics’ were banded on the seed line rather than injected 2 inches below the soil surface.

Palumbo’s question was upon plant germination and the sprinkler incorporation of the product could Bagrada bug numbers be greatly reduced.

“This application did not effectively protect the plants from the insect,” Palumbo said. “The cotyledon failed to load up with enough insecticide so damage was still rampant.”

In other studies, Palumbo investigated conventional and alternative foliar insecticides for Bagrada bug control. Much of the research is ongoing.

In summary, Palumbo offered these Bagrada bug management tips for low desert cole crop production.

First, fields near grassy areas (including sudangrass), weedy drains, and residential and desert areas may be at a higher risk for Bagrada bug infestations.

Second, monitoring and scouting for the Bagrada bug is important. The insect spends early morning hours in the soil. Sampling after 9 a.m. is recommended. Look for damage under cotyledons and young leaves. Look for adults on the underside of cotyledons and the soil.

Third, Bagrada bug control should include chemigation at emergence in high-risk areas. While farmers already chemigate for the flea beetle and other insects, Palumbo suggests another chemigation preferably four to five days before the plants are lined out for planting.

“Once the pipe is pulled, you need to protect the plants from the Bagrada bug,” Palumbo said. “Pyrethroids provide the best activity by contact. Other effective products include Lannate and Lorsban, followed by Venom, Scorpion and Belay.”

The Bagrada bug can also damage papaya, potato, maize, sorghum, cotton, capers, and some legumes.

cblake@farmpress.com