Proteomic and molecular analyses of esterases associated with monocrotophos resistance in Helicoverpa armigera

► Monocrotophos resistance in MonoR was suppressed by the esterase inhibitor DEF. ► MonoR show higher in vitro esterase activities than a susceptible strain (SCD). ► Overexpression of Clade 1 esterases was associated with monocrotophos resistance. ► Two ace genes were not associated with monocrotophos resistance. ► Esterase-mediated detoxification is a major mechanism for monocrotophos resistance.