Silencing of ATP synthase β reduces phytoplasma multiplication in a leafhopper vector

•RNAi in the phytoplasma vector Euscelidius variegatus is long-lasting.•Silencing of ATP synthase β transcript reduces expression of the cognate protein.•dsRNA injection generates siRNAs mapping only on the fragment used to design dsRNAs.•Silenced insects acquire chrysanthemum yellows and Flavescence dorée phytoplasmas.•Silencing of ATP synthase β reduces the multiplication of both phytoplasmas.