Functional response of adults of Oenopia conglobata (L.) to different densities of Schizaphis graminum (Rondani)

In this research the functional response of lady beetle adults, Oenopia conglobata (L.) (Col.: Coccinellidae) to different densities of forth instar nymphs of Schizaphis graminum (10, 20, 25, 30, 40 and 50) as prey, was studied in a growth chamber (25±1˚C, 65± 5% RH and a photoperiod of 16L: 8D h) on wheat. The number of prey killed by the predator was recorded at each density after 24 hours. Type of functional response was determined by logistic regression. Moreover, the parameters of the searching efficiency (a) and handling time (Th) were calculated using Rogers’ model. A type II functional response for lady beetle adults to different densities of S. graminum was obtained. The values of searching efficiency (a) and handling time (Th) for this predator were estimated 0.070±0.012 h-1 and 0.453±0.100 h, respectively. The results of this research could be useful for employing this predator in integrated management programmes of S. graminum.