Relation of fruit color, elongation, hardness, and volume to the infestation of olive cultivars by the olive fruit fly, Bactrocera oleae

The susceptibility of olive cultivars to the olive fruit fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae),has seldom been studied. This article examines factors associated with olive fruit fly infestationof 16 commonly planted Sicilian olive cultivars. Total infestation data were simultaneously correlatedwith categorical and quantitative factors using ordinal logistic regression. When all factors wereincluded in the analysis, year, sampling date, cultivar, and fruit color were highly significant, but thequantitative factors fruit volume, fruit elongation, and fruit hardness were not. When the analysiswas repeated excluding cultivar, all quantitative factors were significant, and elongation and volumewere highly significant. Spherical, large, and hard fruit seemed to be preferred by B. oleae over fruitthat are elongate, small, and soft. Therefore, fruit color, elongation, volume, and hardness provideuseful information regarding the susceptibility of cultivars. In both organic and conventional olivecultivation, information about olive cultivar susceptibility to olive fruit fly will help orchard managersto produce quality oil and table olives while reducing treatments for olive fruit fly control.