Foliar application of systemic insecticides disrupts feeding behavior of the whitefly Bemisia tabaci MEAM1 and the transmission of tomato chlorosis virus in potato plants

Abstract

The whiteflies of the Bemisia tabaci (Genn.) complex (Hemiptera: Aleyrodidae) are serious agricultural pests that cause severe losses to vegetable, ornamental and fiber crops, including potato plants, mainly as a vector of economically important viruses. Among the most important viruses affecting potato is tomato chlorosis virus (ToCV) (Closteroviridae: Crinivirus), which is semi-persistently transmitted by whiteflies of the genera Bemisia and Trialeurodes. Chemical control is the main method used to manage B. tabaci and ToCV; however, this whitefly is resistant to most commercially available insecticides, and some products may not effectively prevent the vector stylet activities associated with virus transmission. The effective management of B. tabaci is crucial to reduce the spread of vector-borne diseases, and to minimize economic losses. We evaluated the effects of the foliar spraying with the systemic insecticides acetamiprid, flupyradifurone and cyantraniliprole on the probing behavior of non-viruliferous and ToCV-viruliferous B. tabaci MEAM1 and ToCV transmission in potato plants. To evaluate ToCV transmission in greenhouse conditions, viruliferous whiteflies were released on potato plants at different time points (3, 24 and 72 h and 7 days) after insecticide spraying. The EPG assay showed that at 3 h after insecticide application, the probing behavior differed, depending mainly on the state of the insects (viruliferous or not), whereas 72 h after application, the probing behavior differed only on plants treated with acetamiprid and flupyradifurone, for both viruliferous and non-viruliferous whiteflies. ToCV transmission was reduced mainly in plants treated with flupyradifurone and acetamiprid, likely as a result of phloem activity disruption.