Investigating the cyantraniliprole dose-response of Bemisia tabaci(Hemiptera: Aleyrodidae) relative to host plant effects

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a polyphagous pest primarily controlled using intensive insecticide treatments to protect high-value vegetable crops. This whitefly is adaptable and has displayed many cases of insecticide resistance to many commonly used chemistries in multiple IRAC classes. Although various insecticide treatment regimens have been developed to mitigate the resistant response, the potential effect of the host plant is mainly overlooked. Polyphagia may benefit B. tabaci in many ways, including inducible chemical response in whitefly, which can impact insecticide response. This study aimed to characterize host crop effects on insecticide (cyantraniliprole (IRAC group 28)) dose-response. The experiment tested five whitefly host crops representing five plant families: Brassicaceae (Collards), Cucurbitaceae (Cucumber); Fabaceae (Cowpea); Malvaceae (Cotton); Solanaceae (Tomato). Host plant effects on the dose-response to the insecticide, cyantraniliprole, were evaluated for the adult life stage. Results were based on the effectiveness of the insecticide on whitefly after feeding for just 48 hours on the different crops. We observed significant shifts in susceptibility/resistance to cyantraniliprole depending on the host plant on which they fed. The underlined mechanisms, such as the interaction with host plant metabolites, still needs further evaluation. This study highlights the need to incorporate host crop effects in B. tabaci insecticide resistance management.