Fruits get stung which causes dark purplish dots on the fruit followed by mild signs of tissue decomposition due to secondary pathogens. The fruits tend to drop. Infected fruits will develop a water soaked-like appearance.
Fruit flies are considered a serious pest of olive cultivation with worldwide reports of infestation levels reaching up to 100% in some cases.
Females lay their eggs inside fruits. Larvae feed by tunneling through the interior of fruit. Injured fruits are susceptible to fungi invasion.
Scout your field on a regular basis. Look for fruits that appear they’ve been stung. If you have monitoring traps (not the same as capturing devices) check them for a better understanding of infestation levels.
Depending upon the host, destination market, timing, and progression of season, some levels of infestation might be considered tolerable.