Field evaluation of the egg parasitoid, Trichogramma evanescens West. against the olive moth Prays oleae (Bern.) in Egypt

In Egypt, Trichogramma evanescens Westwood (TE) is extensively used in inundative releases against a number of lepidopterous pests of several crops. However, the wasp had not been collected from olive groves. Field trials on the use of commercially available TE against the olive moth, Prays oleae (Bern.) (OM) were carried out for three successive years (2002-2004). The objective of this study was to evaluate the efficacy of inundative releases of this wasp on damage reduction. The obtained results were encouraging since OM attacks were reduced by 42.9,71 and 69.9% and TE-treated trees yielded significantly bigger olive fruits by 10.5 and 12.5% than untreated trees in 2002 and 2004 olive seasons, respectively. However, parasitization levels indicated that the wasp is not well adapted to local environmental conditions of olive groves. The suggested measure to improve the quality of released wasps is to mass release of local wasps isolated during the present study, i.e., T. cordubensis Vargas and Cabello and T. euproctidis Girault.