Differences in susceptibility of the cabbage seed weevil (Ceutorchynhus assimilis Payk.) (Coleoptera: Curculionidae) and the pollen beetle (Meligethes aeneus F.) (Coleoptera: Nitidulidae) to indoxacarb and deltamethrin and resistance mechanisms of the cabbage seed weevil to indoxacarb

The pollen beetle, Meligethes aeneus F. (Coleoptera: Nitidulidae) and the cabbage seed weevil, Ceutorhynchus assimilis (Payk.) (Coleoptera: Curculionidae) are two most dangerous winter rape pests in Europe, which frequently co-occur on fields. Difficulties in controlling both pest species stem not only from their resistance to various active ingredients of insecticides, but also from significant differences in their susceptibility to the same active ingredients. The aim of our research was to establish the level of susceptibility of the pests to deltamethrin, a pyrethroid, and indoxacarb, an oxadiazine, and to determine enzymatic mechanisms of resistance to indoxacarb in the cabbage seed weevil, using pesticide synergists that block particular groups of enzymes. The results have shown that the pollen beetle was highly resistant to deltamethrin and highly susceptible to indoxacarb, while the cabbage seed weevil was highly susceptible to deltamethrin and highly resistant to indoxacarb. Studies of resistance mechanisms to indoxacarb in the cabbage seed weevil have not indicated participation of oxidative enzymes blocked by piperonyl butoxide, esterases blocked by S,S,S-tributylphosphorotrithioate or glutathione transferases blocked by diethyl malonate in the metabolism of this substance. Thus, further research on mechanisms behind the resistance of the cabbage seed weevil to indoxacarb is necessary.