This study, was carried out to determine the most effective species or strains among Trichogramma evanescensWestwood (from Sakarya-Turkey), T. evanescensWestwood (from Adana-Turkey), T. evanescensWestwood (from Moldavia), T. ostriniaePang et Chen (from China), T. evanescens Westwood (from Darmstadt-Germany), T. brassicae Bezdenko (from Aydin-Turkey) and T. maidis Pintureau & Voegele (from France), which were investigated or used for biological control against O. nubilalis in different countries. A single female was offered choice between 2x40 eggs of O. nubilalis and 2x50 eggs of Sitotroga cerealella (Olivier), sticked on the corner of a white paper (2x2 cm) with one honey drop in the tubes. Observations after releasing were made to study the behavoir of parasitoids on the host eggs for every 30 minutes during 4 hours. All Trichogramma strains were accepted eggs of the O. nubilalis and S. cerealella. The ratio of the contact of T. evanescens (from Sakarya-Turkey), T. evanescens(from Adana-Turkey), T. evanescens(from Moldavia) and T. ostriniae on the O. nubilalis eggs were 62.50, 61.35, 58.83 and 56.00%, respectively. But, the average number of the parasitized eggs per female of T. ostriniae(13.80) was higher than the others. As a result, the most effective candidade for biological control of O. nubilalis was T. ostrinae and T. evanescens(from Adana-Turkey) in laboratory.

This study, was carried out to determine the most effective species or strains among Trichogramma evanescensWestwood (from Sakarya-Turkey), T. evanescensWestwood (from Adana-Turkey), T. evanescensWestwood (from Moldavia), T. ostriniaePang et Chen (from China), T. evanescens Westwood (from Darmstadt-Germany), T. brassicae Bezdenko (from Aydin-Turkey) and T. maidis Pintureau & Voegele (from France), which were investigated or used for biological control against O. nubilalis in different countries. A single female was offered choice between 2x40 eggs of O. nubilalis and 2x50 eggs of Sitotroga cerealella (Olivier), sticked on the corner of a white paper (2x2 cm) with one honey drop in the tubes. Observations after releasing were made to study the behavoir of parasitoids on the host eggs for every 30 minutes during 4 hours. All Trichogramma strains were accepted eggs of the O. nubilalis and S. cerealella. The ratio of the contact of T. evanescens (from Sakarya-Turkey), T. evanescens(from Adana-Turkey), T. evanescens(from Moldavia) and T. ostriniae on the O. nubilalis eggs were 62.50, 61.35, 58.83 and 56.00%, respectively. But, the average number of the parasitized eggs per female of T. ostriniae(13.80) was higher than the others. As a result, the most effective candidade for biological control of O. nubilalis was T. ostrinae and T. evanescens(from Adana-Turkey) in laboratory.