Abstract Hyalesthes obsoletus Signoret (Hemiptera: Auchenorrhyncha: Cixiidae) is a univoltine, polyphagous planthopper that completes its life cycle, including the subterranean nymph cryptic stage, on herbaceous weeds. In vineyards, it can transmit ‘ Candidatus Phytoplasma solani’, an obligate parasitic bacterium associated with bois noir (BN) disease of grapevine, from host plants to grapevine...