Samane Soltantoieh - Msc. Student, Plant protection Dep., Faculty of Agriculture, University of Maragheh
Gholamhossein Gharekhani - Assistant Professor, Plant protection Dep., Faculty of Agriculture, University of Maragheh
mohammadreza Damavandian - Assistant Professor, Plant protection Dep., Faculty of Agriculture, University of Sari.

The parasitoid wasp Trichogramma brassicae is a dominant species in the North of Iran. In order to studythe behavior of this species in the Maize fields in the Dasht-e-Naz region of Sari State, it is reared on the eggsof the flour moth. Wasps were marked using fluorescent powder and released from a central point.Parasitization was studied by using trap cards including the eggs of the intermediate host at distances(including 2, 5, 9, 12, 18 and 25m) and heights (including 20, 50 and 100 Cm). Parasitized eggs werecollected after three days of release and studied after six days in the laboratory. Statistical analysis usingGLM indicated that the effects of distances and heights were significant (P< 0.001) as well as the interactionof the height and the mean daily temperature. R2 calculated equal to 79%. Mean comparison revealed that thehighest parasitization occurred in the first and third heights. In addition, parasitization rates were nonsignificantin distances 2-9 m while in other distances were significant. Hence it is necessary the distance andheight of this parasitoid to be considered with the purpose of increasing the efficiency of biological control aswell as intended and economic utilization of the biocontrol agents.