Inducing Resistance in Olive Seedlings against Olive Psyllid, Euphyllura straminea Using Natural Phenol Compound

Olive psyllid Euphyllura straminea Loginova was recorded as a key pest in Egypt in 1988 on olive trees in El Arish and caused considerable losses in fruit yield. This work aims at evaluating the toxic and repellent effect of a natural phenol compound (3, 4 dihydroxy phenol ethanol) to control and induce resistance to olive seedlings against this insect pest under insectary conditions. Results showed that percentages of reduction of insect population were increased as the phenol compound concentrations increased. The reduction percentage of nymphs and adults were reached 100% after 15, 18, 21 days at concentration of 1.0, 0.75 and 0.5 mM, respectively. Also this compound was more effective on nymphal stage than adults. Spraying this natural phenol compound (3, 4 dihydroxy phenol ethanol) could be used to control and induce resistance to olive seedlings against this pest infestation. Also results indicated that increasing concentration of 3,4 – DHPE found to prolong the protective period from 17, 27 and 35 days at 0.50, 0.75 and 1.00 mM concentrations, respectively. Therefore this compound could be used to induce resistance of olive trees against olive psyllid infestation.