D3374: Impact of cyclaniliprole and flonicamid on green peach aphid and its natural enemies Aphidius colemani and Hippodamia convergens

The increasing use of natural enemies in modern agriculture makes it vital to study the impact of insecticides on these organisms. The objective of this study was to determine the residual effect of two active ingredients cyclaniliprole, flonicamid and the combination of both on green peach aphids Myzus persicae (Sulzer) and two of its natural enemies: the parasitoid, Aphidius colemani Viereck and the predator Hippodamia convergens Guérin-Méneville. Zinnias plants were grown in a greenhouse at 24ºC/14:10 (L:D) using standard practices. At day 0 (D0), five treatments were applied as drenches: an untreated control; cyclaniliprole at 1.30 ml/L; flonicamid at 0.34ml/L; cyclaniliprole + flonicamid at 1.07ml/L; and cyantraniliprole at 0.63ml/L. Their residual effect was evaluated in laboratory bioassays at D0, D7, D14, D21 and D28 where insect survival was observed at 24 and 72h. Residual effects were observed by all the chemicals evaluated. The main effect on survival was observed on M. persicae and was consistent up to D21 at the 72h evaluation. The chemicals cyantraniliprole, the combination of cyclaniliprole + flonicamid and flonicamid reduced survival. On H. convergens however, none of the treatments significantly reduced its survivalat any evaluation time. Meanwhile on A. colemani, the combination of cyclaniliprole + flonicamid showed residual effects until day 21 reducing its survival at the 24 h. In summary, the impact of insecticides on biological control agents varies depending on the active ingredient and the type of biological control agent used.