The infestation percentage of olive fruit by olive (Dacus oleae ) in North Sinai
was evaluated . A survey of the national enemies of Dacus oleae was conducted and
the percentages of parasitism was determined. In addition, the effect of different
percentages of infestation of olive fruits being, 0, 5, 10, 20 and 40% were used to
study its effect on the physical and chemical properties and organoleptic test of olive
oil of Picual and Manzanello varieties cultivated in ::I-Ariash only. The results are as a
follows: _ Infestation by olive fly D. oleae caused decrease in oil content of olive fruits. Picual and Manzanello varieties. -The acid value, peroxide value and UV absorption at 232 and 270 nm. were
increased gradually with increasing infestation percentages, while the refractive
index decreased by infestation. -Infestation at 20 and 40 % showed a highest increase in acid value, peroxide value
and U.V. absorption, with highest decrease in oil content. -There is no appreciable changes in moisture content as a result of infestation. -The results of organoleptic test indicated that, the olive oil of Picual and Manzanello varieties, could be used up to 10% infested fruits.