Functional response of Serangium montazerii (Col.: Coccinellidae) to different densities of Dialeurodes citri (Hem.: Aleyrodidae): an open-patch approach

The functional response of a predator is the base of prey-predator dynamics. Functional response of Serangium montazerii Fürsch at different egg densities (۵۰, ۱۰۰, ۱۵۰, ۲۰۰ and ۲۵۰) of Dialeurodes citri (Ashmead) was studied in an open-patch experiment, in a growth chamber (۲۵ ± ۱°C, ۶۵ ± ۵% RH and a photoperiod of ۱۶: ۸ L: D h) on ‘Thompson’ navel orange (Citrus sinensis cv. Thompson) apical leaves. A type II functional response was obtained using logistic regression. The searching efficiency (a') and handling times (Th) of the female adults using nonlinear least-square regression were estimated as ۰.۰۴۲۱ ± ۰.۰۰۹۴۵ h-۱ and ۰.۰۸۹۶ ± ۰.۰۳۶۲ h, respectively. Mean times required for the female predator to settle in a patch were ۱۲۱.۴, ۱۴۰, ۱۱۶, ۸۳ and ۷۸ minutes at above-mentioned prey densities, respectively. It was inversely density dependent (R۲ = ۰.۷۴۰). The proportion of female predators remaining in open patches at the end of the experiment was directly dependent on prey density (R۲ = ۰.۹). It was concluded that the type of functional response obtained here was in agreement with studies on this predator in closed patches.

کلیدواژه ها:

Serangium montazerii ، تراکم های مختلف ، واکنش تابعی ، open patch