Application of inundative releases of Trichogramma evanescens to control the olive moth, Prays oleae (Bern.)
Field releases of 900000 wasps/ha/release of Trichogramma evanescens were applied against the anthophagous (March 9 th , 26 th ; April 4 th , 22 nd ) and carpophagous (May 13 th , 27 th ; June 10 th , 24 th ) generations of the olive moth Prays oleae . A comparable olive grove (0.5 ha) of the same olive varieties (Toffahi and Shamy) was chosen as control site. The flight phenology of the olive moth males was weekly monitored with sex pheromone traps. Estimation of infestation rates by target pest on olive leaves, flowers, fruits and pre-mature fallen fruits as well as parasitism by Trichogramma evanescens were weekly recorded. Olive fruit yield of treated and untreated areas was carefully gathered and weighed. Interestingly, male catches in treated sites were greatly reduced from the 3 rd release of the first flight to the last release of the 2 nd flight of the olive moth. Reduction in male catches in treated plots resulted in decreasing number of eggs of target species on olive shoots in treated sites compared to control site. The maximum percentage of parasitism in Prays eggs occurred in May 27 th . Results of the efficacy of releasing wasps on the amount of premature fall of olive fruits and fruit yield/tree (weight and number) at treated and control sites offer encouraging data concerning the protection of olive yield by inundative releases of Trichogramma wasps. Importantly, a thelytokous strain of T. cordubensis was reared for the first time in Egypt from naturally parasitized P. oleae eggs and will be tested in the near future.
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