The Effects of Host Plant Architecture on Functional Response of Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae)

The structure, number, and size of plant parts may have an effect on predator’ functional response. The study focused on how two characteristics of plant architecture, the numbers of leaves and branches, will affect the functional response of Cryptolaemus montrouzieri on chili pepper plant (Capsicum annuum L., cv. ‘Jalapeno’) when provided varying densities of the citrus mealybug. Peppers differed in leaf number (5, 10 and 15) and branch number (2, 4 and 6). The plants were associated differences in leaf size and height; but all had the same total leaf surface area and stem surface area. The preys, the citrus mealybug Planococcus citri, were provided in even distribution on top surface of leaves with 5 densities (2, 4, 8, 12 and 16 per plant). Each treatment was conducted in a 24x24x36cm cage. The influents of plant architecture on predator’s functional responses were different according to the complexity of the structure. Our results suggest that both leaf number and branch number are very important factors to be considered in future use of C. montrouzieri as a world wide biological control agent.