THE PREDATION EFFICIENCY AND FEEDING PREFERENCE OF COCCINELLA SEPTEMPUNCTATA L. AND COCCINELLA UNDECIMPUNCTATA L. (COLEOPTERA: COCCINELLIDAE) ON SOME PREY SPECIES

To enhance the strategy of the biological control of the sucking insect pests using the Ladybird Beetles (Coleoptera: Coccinellidae), it is important to understand predator–prey interactions. Hence, the predation efficiency and preference of both larvae and adult of seven-spot ladybird, Coccinella septempunctata Linnaeus and the eleven-spot ladybird, Coccinella undecimpunctata Linnaeus on four prey species i.e., the green peach aphid, Myzus persicae (Sulzer), the cotton aphid, Aphis gossypii Glover, the bird cherry-oat aphid, Rhopalosiphum padi (Linnaeus) and onion thrips, Thrips tabaci Lindeman were evaluated under laboratory conditions at varying prey densities using a clear glass jars.There were significant differences between the consumed numbers of the four different species by the two different lady beetle species. The most consumed prey by C. septempunctata was the A. gossypii followed by M. persicae then R. padi and finally T. tabaci and these results were repeated in case of C. undecimpunctata with less feeding voracious. As the grubs of C. septempunctata and C. undecimpunctata developed from 1st to 4th larval instars, the consumption rates from aphid species and thrips increased. The consumption rates of M. persicae, A. gossypii, R. padi and T. tabaci significantly increased with the advancement in the larval stage of the two predators. The forth larval instar of C. septempunctata and C. undecimpunctata exhibited the highest predatory potential comparing to the first, second and third larval instars. The numbers of prey eaten by adult stage or different instars of larvae of the two predators increased significantly with prey density and reaching the maximum value when 150 preys were provided compared with 50 and 100 preys.