Functional response of the green lacewing, Chrysoperla carnea larvae on two aphid pests of the citrus: Aphis spiraecola and Aphis gossypii

The green lacewing, Chrysoperla carnea, plays an important role in biological control of various aphid species. In this study, the functional responses of the second and third instar larvae of C. carnea were studied on the citrus aphid, Aphis spiraecola and melon aphid, A. gossypii. The experiments were carried out on orange (cv. Thompson Navel) leaves in a growth chamber at 27 ± 2°C, 65 ± 5% RH and a photoperiod of 16 L: 8 D h. Different densities of the preys were offered to the predators, and the number of consumed preys was calculated after 24 h. Based on the logistic regression analysis, both second and third larval instars of the predator exhibited a Type II functional response to both aphid species. With increasing of the larval instar, the attack rate (a) of the predator on A. spiraecola was significantly increased and the handling time (Th) decreased. Attack rate of second larval instar of the predator on A. gossypii was significantly higher than that on A. spiraecola. Furthermore, the third instar larvae fed on A. gossypii showed significantly lower handling time and higher attack rate compared to A. spiraecola. The results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling A. spiraecola and A. gossypii. However, further field-based studies are needed for a comprehensive estimation of biocontrol abilities of C. carnea toward these two aphids on the citrus.