(Supplementary Data). Analysis of the results showed that almost all of the tested QASs exhibited good antifeedant activity toward adult granary weevils as well as khapra beetle larvae, and very good activity toward confused flour beetle larvae. A deviation from this rule was observed only in the case of 4Br, 4Asp and 4Ala containing a 2-hydroxyl substituent, for which the total deterrence coefficient T toward granary weevil showed values ranging from 81 to 99, comparable to the values achieved for the reference compounds (95). 4Asp was further characterized by significantly worse activity toward confused flour beetle larvae than the rest of the tested compounds and reference substances. Also in our previous studies, we observed that excessive hydrophilicity of the cation can negatively affect deterrent activitycholine analogs and compounds containing hydroxyl or ester groups in the cations are generally characterized by worse T values compared to QASs with cations based on synthetic surfactants with long alkyl chains .