Effect of host plant on the functional response of Orius albidipennis females to densities of egg or adult female of Tetranychus urticae was investigated using cucumber and strawberry plants that differ in leaf morphological features. The functional response experiments of predatory bugs on egg and adult female of T. urticae were examined over 24 and 8 h periods, respectively. Logistic regression analysis revealed that O. albidipennis predation fitted reasonably well to both type II and III functional response models. Predators showed type II response to adult female of T. urticae on both host plants but they had type III response to T. urticae eggs on their host plants. Attack rates (a) of predatory bug to adult female of T. urticae on cucumber and strawberry were 0.031 and 0.047/h, respectively. Moreover, attack coefficient b, which describes the changes in attack rate with prey densities in a type III response (a=b N), of O. albidipennis to T. urticae eggs on cucumber and strawberry was 0.001 and 0.004/h, respectively. Predator handling times (Th) to adult female and T. urticae eggs on cucumber were greater than those on strawberry, with estimated values of 0.94 vs.1.54 and 0.81 vs. 0.76 h for adult female vs. T. urticae eggs on cucumber and strawberry, respectively. The implications of these results for the tritrophic interactions between plant, prey and predator, and the development of suitable biological control strategies are discussed

Keywords