ABSTRACT
Field experiments were carried out in four areas of Brittany with a view to determining the movements of diamond-back moths (Plutella xylostella) to host plants. Two varieties of Brassica oleracea - var. botrytis and acephala - and Brassica napus were studied. Sexual traps were also placed on grass and barley. The catches showed that the moths shelter under old Brassica oleracea and Brassica napus during spring from where they may fly to new Brassica sowings or young plants but not to other plants. In the case of young Brassica, they are probably attracted by the volatile flavour substances such as isothiocyanate resulting from enzymatic glucosinolate degradation.
Field experiments with genetically selected cruciferous vegetables with and without glucosinolate will be considered.
