Functional Responses of Hippodamia variegata (Goeze) and Coccinella septempunctata (L.) (Coleoptera: Coccinellidae) on Aphis fabae Scopoli and Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae)

In this study, the functional responses of aphid predators Hippodamia variegata (Goeze) and Coccinella septempunctata L. (Coleoptera: Coccinellidae) were tested. In these experiments, the amount of prey consumed by the predator insects at different aphid densities and the effect of this on the reduction of aphid populations were examined. The larvae (L1, L2, L3, and L4) and adults of the predators were starved for 24 hours. Afterward, the second and third instar larvae of the aphid species Aphis fabae and Acythosiphon pisum were offered as prey in specific numbers (5, 10, 20, 40, 80, and 160). After providing the prey, the predators were allowed to feed for another 24-hour stage, and the amounts of prey consumed were recorded. The results showed that the attack rates (a) of the predator insects increased as their developmental stage progressed, while the handling time (Th) decreased. Based on the data, it was concluded that both predator species, especially in the later stages of their developmental stages, had high prey consumption on A. fabae and A. pisum and could be effective in the control of these pests.