Use of a copolymer of N-vinyllactam / vinylimidazole as dispersing agent

A use of a copolymer comprising a) N-vinyllactam, b) vinylimidazole or quaternized vinylimidazole in polymerized form as a dispersing agent in an aqueous composition containing a water-insoluble pesticide having a water solubility up to 10 g / at 20 ° C.