Functional and numerical response of Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae) on Macrosiphum rosae (L.) (Hemiptera: Aphididae)

Abstract

In this study, functional and numerical response tests, which are important components in the selection of biological control agent, were carried out. In functional response trials, the amount of food consumed, attack rate (a) and handling time (Th) were calculated for each developmental period, depending on the number of preys given after 24 hours. The obtained results were evaluated with the Holling. In numerical response experiments, the development of the predator insect was examined depending on the number of preys given in certain numbers (5, 10, 20, 40 and 80) and the data were recorded. This phase of the trials continued until the individuals died. At this stage of the trials, the reproductive response of the predator on the aphid and the prey use efficiency were calculated. All of the productions and trials were carried out in climate rooms with a temperature of 27±1 °C, 65±5% RH. Experiments were carried out with 50 replications for each growth period and prey densities. According to the results obtained in the functional response trials, it was determined that the development periods with the highest productivity were the fourth larval and adult stages. When the results obtained from the numerical response experiments were evaluated, it was observed that the reproductive response increased with the increase of the prey given to H. variegata. Considering all the data obtained as a result of the study, it was concluded that H. variegata is effective on M. rosae and can be used in the control of this pest.