Effect of host plant on the functional response of the parasitoid Encarsia lutea (Masi) (Hymenoptera: Aphelinidae) to Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) under laboratory conditions

This study was conducted to determine the parasitism capacity and functional response of the parasitoid Encarsia lutea (Masi) (Hymenoptera: Aphelinidae) on Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) on three host plants. The experiments were performed under laboratory conditions (25±1 °C temperature and 70±5% humidity) to evaluate the functional response of En. lutea at six host densities (10, 20, 40, 60, 80 and 100) of B. tabaci on three hosts including; bean, cotton and eggplant. The results showed that En. lutea is not only parasitizes their hosts but also kills them through feeding and ovipozitor puncturing. While the number of B. tabaci nymphs parasitized by En. lutea varied according to host plants, the highest was found on the eggplant at all host densities. According to logistic regression analysis, population of En. lutea on three different host plants showed a Type II functional response. The attack rate (α) and the handling time (Th) of Type II response were calculated by fitting Holling Disc Equation to the data. These two coefficients were varied depending on the host plants. The highest α and the shortest Th values were determined as a=2.170 and Th 0.009 for eggplant and cotton, respectively.