Effect of Temperature on Functional Response of Carob Moth Egg Parasitoid, Trichogramma brassicae Bezdenko. (Hym.: Trichogrammatidae), Collected from Pomegranate Orchards of Yazd



Ectomyelois ceratoniae Zeller (Lepidoptera.: Pyralidae), is the key pest of pomegranate in Iran. Trichogramma wasps could be used as effective agents of biological control that can also be used effectively in IPM programs. The effect of host density on parasitism of Trichogramma brassicae was studied by exposing densities of 4, 8, 10, 20, 40, 60, 80 and 120 eggs of factitious host (Sitotroga cerealella Olivier) (Lepidoptare.: Pyralidae), in glass shell (1×10 cm) and controlled conditions. Statistical analysis of functional response was conducted in two steps through SAS software. The experiments were carried out at 20, 25 and 30?C. The parasite showed a type II functional response at 25?C and a type III at 20 and 30?C. The searching efficiency (a) and the handling time (Th) at 25?C were 0.073± 0.011 and 0.311± 0.032, respectively. At 20 and 30?C, b was 0.002?0.0005 and 0.005?0.0007 respectively. Th at 20 and 30?C were 0.619?0.028 and 0.425 ? 0.012. To compare the functional response of wasps at 20 and 30?C, an equation with indicator variable was employed. Data analysis revealed that the parameters of functional responses are significantly different at 20 and 30?C.