The size selective predation and functional response parameters of Coccinella septempunctata (L.) (Coleoptera: Coccinellidae)

Khan, M.R. . Dept. of Entomology; Khan, M.R. . Dept. of Entomology; Matin, M.A.

The size selective predation and functional response parameters of Coccinella septempunctata (L.) (Coleoptera: Coccinellidae)

2008

Khan, M.R. (Faculty of Agriculture, Rawalakot (Pakistan). Dept. of Entomology) | Khan, M.R. (Faculty of Agriculture, Rawalakot (Pakistan). Dept. of Entomology) | Matin, M.A. (Pakistan Agricultural Research Council, Islamabad (Pakistan))

The functional response components, attack rate (a') and handling time (Th) of Coccinella septempunctata (L.) were evaluated against three prey sizes (1.0 mm, 1.5mm, and 2.Omm) and seven prey densities (15, 30, 45, 60, 75, 90 and 105) of Myzus persicae. The average prey consumption per unit time against prey size 1.0 mm is 79 preys/arena/12h, which remained significantly higher at all prey densities. The changes in instantaneous attack rate (a') and prey handling time (Th, were the obvious function of prey sizes and their densities. A very high correlations (r2 = 0.96: P less than 0.05) between the prey size and prey consumption rate were found in all developmental stages of predators (1st instar larvae to adult). The 4th instar larvae were found more voracious in consuming prey. Overall, the females consumed more prey than the males and virgin females consumed significantly higher prey during 12 hours.

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