Effect of Leaf Surface Characteristics of Wheat Cultivars on Functional Response of Orius albidipennis (Reuter) to Barely Aphid Sipha maydis (Passerini)

The functional response is an important characteristic of predator–prey interactions that determinate which predator species or stage classes of predator is the most effective for pest control. Host plant morphological characteristics are the effective factors on predator’s functional response. The objective of this study was to determine whether differences in trichome density of wheat cultivars (Falat, Ghuds and Pishtaz) affect the functional response of Orius albidipennis to sipha maydis.Functional response of third nymphal stage and adult female of predatory bug to different densities (4, 6, 8, 12, 24 and 32) of barley aphid was evaluated under laboratory condition (24 ± 1ºC, 60 ± 10 RH and 16: 8 (L: D) photoperiod). Time of each experiment was 24 hours and all experiments were carried out in 10-14 replications. Based on logistic regression, functional response type II was determined for two life stages of predatory bug on tested wheat cultivars. Searching efficiency (a) and handling time (Th) for third nymphal stage on Falat, Pishtaz and Ghuds cultivars were estimated 0.019, 0.021, 0.036 h-1 and 1.17, 2.5, 5.09 h, respectively. In addition, searching efficiency and handling time for female adult were obtained 0.020, 0.018, 0.022 h-1 and 1.35, 1.41, 2.25 h on Falat, Pishtaz and Ghuds cultivars, respectively. Use of an equation with indicator variable revealed that there are significant differences among handling times of third nymphal stage of O. albidipennis on tested wheat cultivars.