Abstract
The cabbage seed weevil, Ceutorchynhus assimilis (Paykull) (Coleoptera: Curculionidae) is a pest that more and more often causes large financial losses for rapeseed cultivators in Poland and other European countries. One of the reasons of these problems is the resistance of the pest to certain active substances of insecticides. The aim of the study was to assess the susceptibility level of the pest to chlorpyrifos, an organophosphate substance, and acetamiprid, a neonicotinoid, and to determine its enzymatic mechanisms of susceptibility to acetamiprid using synergists, i.e., blockers of particular enzyme groups. The presented research is the first to discuss the mechanisms of the resistance of the cabbage seed weevil to acetamiprid. The achieved results showed medium, high, or very high resistance of the cabbage seed weevil to acetamiprid and its lack of resistance to chlorpyrifos. The research on the mechanisms of the resistance of the pest to acetamiprid revealed the participation of hydrolytic enzymes blocked by S,S,S-tributylphosphorotrithioate and glutathione transferases blocked by diethyl malonate in the metabolism of acetamiprid. The results did not show the participation of oxidative enzymes and esterases blocked by piperonyl butoxide in the detoxification of acetamiprid.