Despite resistance to pests and diseases, several insect pests have recently been reported to damage Muscadine grapes. Among them, grapevine aphid, Aphis illinoisensis Shimer is emerging as a serious threat in the principal grape growing areas of Florida. There is a scarcity of information about the phenology and management of grapevine aphid in Muscadine grapes. In this study, we monitored the population of grapevine aphid throughout the year and evaluated the performance of three reduced-risk pesticides (cyazypyr, spinetoram, spirotetramat) along with a positive (malathion) and negative control (water) to manage its population in Florida vineyards. In a field efficacy trial, spirotetramat significantly reduced the grapevine aphid population compared with the control and the residual activity sustained for up to two weeks post-application. The effect of these pesticides was tested on two potential biological control agents, Lysiphlebus testaceipes (Cresson) and Orius insidiosus Say in a laboratory bioassay. Under the IOBC toxicity rating scale, all the tested pesticides except cyazypyr were slightly harmful to harmful in both biocontrol species across 3- and 7-day residual ages.
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