Olive fruit fly.The detection in the late 1990s of the olive fruit fly, a non-native pest insect, has presented significant challenges for the California olive industry. Found now in more than 40 counties, it is here to stay.

"The olive fruit fly is a primary pest of olives worldwide and is particularly troublesome due to its multiple, overlapping generations each year," wrote Hannah Burrack, assistant professor of entomology at North Carolina State University, and co-authors in California Agriculture. "This life history makes understanding olive fruit fly phenology and infestation patterns particularly important for effective management."

Three articles in the special issue of California Agriculture discuss strategies for controlling olive fruit fly, including global exploration to find natural parasites of the fly; extensive statewide monitoring of the pest and its reproduction cycles; and the impact of Central Valley heat on fly activity and populations.

The table olive industry has zero tolerance for fruit damaged by olive fruit fly, but the olive oil industry can accept some infestation without deleterious effects on the oil's quality or taste.

"With early harvest and rapid processing, minor olive fruit fly damage can be tolerated, which can save treatment costs and reduce environmental contamination," Vossen and Kicenek Devarenne wrote in California Agriculture.