The result's of the trapping survey were analyzed to determine host range of olive fruit fly (Bactrocera oleae) in California. Since its first appearance in California in 1998, the olive fruit fly has spread from Los Angeles to 37 counties, including all of the state's commercial olive growing areas. Olive fruit fly was trapped from 19 tree species belonging to nine genera distributed in seven families of angiosperms. Olives (Family Oleaceae) were the preferred host of the olive fruit fly. Family Rosaceae has nine tree species followed by Rutaceae (five tree species) as host of olive fruit fly. Other host tree species were distributed in Anacardiaceae, Fabaceae, Lythraceae and Malpigiaceae. Mostly these hosts comprised of the fruit trees with the exception of Brazilian pepper tree, carob, crape myrtle and ornamental plum.

Keywords: Olive fruit fly, Bactrocera oleae, California