Foraging Behaviour of Cheilomenes sexmaculata Fabricius (Coleoptera: Coccinellidae) Against the Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococcidae)
摘要
The functional response curves provide valuable insights into predator–prey interactions as they establish the link between trophic levels. The present study examines the functional response of the six spotted ladybird beetle, Cheilomenes sexmaculata (F.) (Coleoptera: Coccinellidae) against the different densities viz., 10, 20, 30, 40, 50, 60, 80, and 100 of prey, Paracoccus marginatus Williams and Granara de Willink under the laboratory conditions. The results confirmed a type-II functional response, characterized by a decelerating curve, for the fourth instar grub, adult female and male of the predator. The attack rates (a') estimated using Holling’s disc equation for the fourth instar grub, adult female, and male were 1.05 ± 0.00 h, 1.07 ± 0.00 h, and 1.04 ± 0.00 h, respectively. All three stages exhibited handling times of 0.01 ± 0.00 day. The maximum predation rate per day (Tt/Th) was consistent as 100.00/day across the fourth instar grub and both sexes. In contrast, the attack rates determined by Roger’s random attack equation were higher, with values of 3.14 ± 0.00 h for the fourth instar grub, 3.65 ± 0.00 h for the adult female, and 3.03 ± 0.26 h for the male. Handling times for these stages were also comparable i.e., 0.02 ± 0.26 day for the fourth instar grub, 0.02 ± 0.32 day for the adult female, and 0.02 ± 0.00 day for the male. The maximum predation rate per day (Tt/Th) remained uniform across all the stages at 50.00/day. These results indicate predatory efficacy for C. sexmaculata on the P. marginatus and offer reliability towards its application in the augmentative biological control of the dreaded invasive pest, P. marginatus.