Predator functional response and prey preference of Oenopia sauzeti on Trialeurodes vaporariorum

Objective This study aimed to evaluate the potential of Oenopia sauzeti in controlling and preventing Trialeurodes vaporariorum， thereby providing a theoretical basis for its use in managing this pest.Method Under laboratory conditions， the 2^nd-4^th instar nymphs and female adults of Oenopia sauzeti that had been starved for 24 h were placed with the 4^th instar nymphs of Trialeurodes vaporariorum at different density gradients in a circular insect box. The predation amount of the 4^th instar nymphs of Trialeurodes vaporariorum was recorded， and the predator functional response and searching efficiency of the 2^nd-4^th instar nymphs and female adults of Oenopia sauzeti on the 4^th instar nymphs of Trialeurodes vaporariorum were determined. The predation amount of female Oenopia sauzeti adults at different densities on 4^th instar nymphs of Trialeurodes vaporariorum at the same density was recorded to clarify the self-density interference of female Oenopia sauzeti adults. The predation amount of female Oenopia sauzeti adults on the 4^th instar nymphs and adults of Trialeurodes vaporariorum of different densities was recorded to clarify the predation preference of female Oenopia sauzeti adults.Result The functional response of the 2^nd-4^th instar nymphs and female adults of Oenopia sauzeti to the 4^th instar nymph of Trialeurodes vaporariorum fit the HollingⅡdisc equation model. The instantaneous attack rates of the 2^nd-4^th instar nymphs and female adults of Oenopia sauzeti to the 4^th instar nymphs of Trialeurodes vaporariorum were 1.008， 0.996， 1.234 and 1.187， and their handling durations were 0.030， 0.012， 0.009 and 0.008 d respectively. The predation capacity of the female Oenopia sauzeti adults to the 4^th instar nymphs of Trialeurodes vaporariorum was the highest （148.363）， followed by the 4^th instar nymphs （134.109）， the 3^rd instar nymphs （81.630） and 2^nd instar nymphs （33.378）. The searching efficiency of the 2^nd-4^th instar nymphs and female adults of Oenopia sauzeti on the 4^th instar nymphs of Trialeurodes vaporariorum decreased with increasing prey density. Under the conditions of fixed density of the 4^th instar nymphs of Trialeurodes vaporariorum， the predation rate of Oenopia sauzeti decreased as its self-density increased， and the interference equation was E=1.448P^-0.116. When both the 4^th instar nymphs and the adults of Trialeurodes vaporariorum coexisted， the female Oenopia sauzeti adults showed a predation preference for the 4^th instar nymphs of Trialeurodes vaporariorum.Conclusion Oenopia sauzeti shows a predation preference and significant control potential against the 4^th instar nymphs of Trialeurodes vaporariorum.