Desert farmers face a new pest threat

Nov 16, 2009

Farmers growing vegetables in Southern California and Arizona deserts had to contend with a new pest this fall. The Bagrada bug - a native of East and Southern Africa, Egypt, Zaire and Senegal - made its first appearance in the area, posing especially significant problems to organic farmers, according to an article in Capital Press.

Bagrada bugs were introduced to California last year in Los Angeles and San Diego counties. This past August, farmers began seeing the pest in broccoli, cauliflower, and other cole crops in the Imperial and Coachella valleys, and in southwestern Arizona.

“Bagrada bugs were everywhere; it’s not like we’ve had to look for them,” the story quoted John Palumbo, an extension specialist at the University of Arizona Yuma Agricultural Center.

According to UC Riverside’s Center for Invasive Species Research, adult Bagrada bugs are 5 to 7 millimeters long with black, shield-shaped bodies and distinctive white and orange markings. The adult female is larger than the male.

Bagrada bugs suck sap from young leaves causing small white patches on leaf edges. The damage can prevent the plant from producing edible vegetable heads or can cause double heads that are too small for market. Severe Bagrada feeding can kill the plant.

Capital Press reporter Cary Blake spoke to UC Cooperative Extension Imperial County farm advisor Eric Natwick about the Bagrada bug situation for California desert farmers. Natwick said he saw major Bagrada bug damage in an organically grown red cabbage field in Holtville in late October.

“I’d estimate about 30 percent of the early September-planted transplants developed single heads,” Natwick was quoted. “The other plants (about 70 percent) had no head or two smaller, unmarketable heads.”

Natwick found higher single-head numbers in mid-to-late September-planted cabbage. The field contained adults, nymphs, and eggs.


By Jeannette E. Warnert
Author - Communications Specialist

Attached Images:

Female and male Bagrada bugs. (Photo: LA Ag Commissioner's office)