Glucosinolates may act as a potent feeding deterrent for generalist insect species,as their toxicity causes developmental and fitness damage.For insects specialized in brassicaceous plants,however,they may act as oviposition and feeding stimulants,because the toxic effects are circumvented by excretion,detoxification or sequestration mechanisms.We performed a two-year field study to investigate whether the abundance of the generalist Mamestra brassicae (Lepidoptera,Noctuidae) and the specialist Pieris rapae (Lepidoptera,Pieridae),was affected by the glucosinolate patterns of six genotypes of Brassica oleracea var.acephala (kale),selected from the same cultivar for having high or low foliar content of sinigrin,glucoiberin and glucobrassicin.