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 fã¼rsch at different egg densities (50, 100, 150, 200 and 250) of dialeurodes citri (ashmead) was studied in an open-patch experiment, in a growth chamber (25 â± 1â°c, 65 â± 5% rh and a photoperiod of 16: 8 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 0.0421 â± 0.00945 h-1 and 0.0896 â± 0.0362 h, respectively. mean times required for the female predator to settle in a patch were 121.4, 140, 116, 83 and 78 minutes at above-mentioned prey densities, respectively. it was inversely density dependent (r2 = 0.740). the proportion of female predators remaining in open patches at the end of the experiment was directly dependent on prey density (r2 = 0.9). it was concluded that the type of functional response obtained here was in agreement with studies on this predator in closed patches.