Functional response of the lady beetle Hyperaspis campestris (Herbst 1783) to varying densities (1, 5, 10, 15, 20 and 25) of Dactylopius opuntiae (Cockerell) young females (20 days old) were determined under controlled conditions at 26±2°C, 60±10 % RH and 12:12 h L:D regime. The searching efficiency of H. campestris considerably decreased as prey density increased. The significant linear coefficient (P1) obtained by logistic regression had a negative indicating functional response type II. Attack rates (0.151, 0.101, 0.097, 0.122, 0.124 and 0.135) and handling times (3.848, 5.171, 5.417, 4.245, 4.356 and 3.940) for 1 to 25 density, respectively, were recorded using Holling‘s disc equation. Most of this handling time was spent in removing the wax covering and protecting the young females of the mealybug. H. campestris feeds on young females of D. opuntiae and could therefore be an effective predator to regulate to low-density populations of D. opuntiae.
Volume 12 | 01-Special Issue