Naturally occurring Trichogramma species in olive farms in Egypt

Abstract A survey of two-year studies (2001–2003) was carried out in two olive groves sited at two representative olive growing areas, namely Paradise Park (arid area) and Burg El-Arab farm (semi-arid area) to monitor the frequency of endemic Trichogramma species on olive moth ( Prays oleae ) and jasmine moth ( Palpita unionalis ). The suspended host bait traps were found to be a more practical and effective tool for collecting Trichogramma wasps than the attached ones. Four naturally occurring Trichogramma species were collected for the first time in Egypt from the olive groves, where releases have never been conducted. T. bourarachae was collected exclusively from Burg El-Arab farm. It seems that this wasp species adapts well to the semi-arid area. Three species, namely T. cordubensis , T. nr. pretiosum and T. cacociae were isolated from Paradise Park farm. All of these wasps were also bred from naturally parasitized host eggs during favorable and even at unfavorable temperature conditions of June-August. However, these endemic species did not occur naturally in sufficient numbers to keep the pest populations from reaching damaging levels. The excessive usage of insecticides and the oophagous predators (e.g., ants and lacewing larvae) are some factors that affect the performance of Trichogramma wasps in olive farms. The presence of warm weather wasp strains suggests the existence of well-adapted wasp species or strains which may be appropriate candidates for the control of target pests in olive groves. Additional study is required to determine the best "habitat-specific" species/strains of Trichogramma for augmentative release of naturally occurring wasps and to incorporate them into integrated pest management programs. Efforts should be made to conserve these endemic species from oophagous predators, hot weather and insecticides. The olive and jasmine moth-larvae and pupae found under tree canopies were bred and emerged parasitoids were listed.