“…Indeed, whereas in some cases resistance persisted in the absence of the insecticide (Croft & Meyer, 1973;Hoy, 1990;Kostiainen & Hoy, 1994;Glazer et al, 1997;Sayyed et al, 2010;Mansoor et al, 2017), in others it declined (Robertson, 1957;Meyer, 1975;Croft & Hoying, 1975;Spollen & Hoy, 1992;Zhu et al, 1996;Jalali et al, 2006b), possibly because the acquired resistance was a plastic response or due to costs of resistance in an insecticide-free environment. Indeed, whereas in some cases resistance persisted in the absence of the insecticide (Croft & Meyer, 1973;Hoy, 1990;Kostiainen & Hoy, 1994;Glazer et al, 1997;Sayyed et al, 2010;Mansoor et al, 2017), in others it declined (Robertson, 1957;Meyer, 1975;Croft & Hoying, 1975;Spollen & Hoy, 1992;Zhu et al, 1996;Jalali et al, 2006b), possibly because the acquired resistance was a plastic response or due to costs of resistance in an insecticide-free environment.…”