The use of 2,4,5-halogenimidazoles of the formula ##SPC1## order Wherein X.sub.1, X.sub.2 and X.sub.3 each denote a halogen atom, with the proviso that at least one of the substituents X.sub.1, X.sub.2 and X.sub.3 is fluorine, bromine or iodine, for combating harmful insects and representatives of the ordr Acarina.
