تقويم ضرر بسيلا الزيتون Euphyllura straminea Loginova (Homoptera : Aphalaridae) في سورية

This research was conducted to evaluate the damage caused by olive psylla on the olive varieties “surani”, “khalkhalie” and“khuderi” in three Syrian provinces: idleb, tartus and lattakia (jableh). the effects of olive psylla on flower set and on the average number of flowers per clusters were significant, and most damage was caused by the 4th and 5th instar nymphs. the actual loss of flower clusters was33.25% (16 olive fruits, per 100 remained clusters, when the average number of nymphs was 6.61 per cluster). this study showed obvious differences among the three olive varieties in the three locations studied, based on the correlation coefficient between the percentage loss of flower clusters and the average number of nymphs per cluster. the correlation coefficient between the number of olive fruits per 100 remained clusters and the number of nymphs per cluster was also determined.