TRICHOGRAMMA PINTOI R؟GELE تاثير نوع ميزبان آزمايشگاهي بر واكنش تابعي زنبور پاراژيتوييد

The effect of the type of labotatory host on functional response of Trichogramma pintoi Voegele (Hym., Trichogrammatidae)

Functional response of Trichogramma pintoi that reared on Ephestia kuehniella and Sitotroga cerealella was studied to different densities of eggs of mentioned hosts. Two main parameters (searching efficiency and handling time) in two experiments were compared. The main purpose of this study was to determine the effect type of laboratory host (in size and quality) on one of the most important behavioral characteristics (functional response). The study of this behavior is an important method for assessing the efficiency of natural enemies. Parasitoid wasps were reared on two different hosts until 150ʹ generation and then were used for experiments. Different egg densities that were used in both experiments were 2, 4, 6, 8, 14, 20, 30, 40 and 50. Each of these egg densities were inserted inside the test tube and then exposed to a mated female for 24 hours. Analysis of functional response was conducted on two stages by SAS software. At the first stage, logistic regression of proportion of estimated parasitized eggs was used for determining type of functional response. At the second stage, nonlinear regression was used for estimating searching efficiency and handling time parameters. In both experiments functional response was type III and Rolling disc model was used to estimate the parameters. Searching efficiency, handling time, estimated maximum number and percent of parasitized eggs for parasitoids that reared on E. kuehniella were 0.0048, 0.965, 22.88 and 84.29, respectively and for them that reared on S. cerealella were 0.0016, 1.169, 16.92 and 44.03, respectively. The high rate of searching efficiency and low rate of handling time of parasitoids that reared on E. kuehniella indicates the high efficiency of these wasps in comparison with those reared on S. cerealella.