The results of long-term studies of the ability of the inbred population of Drosophila melanogaster living in a vegetable store to adapt to the genotoxic effect of a half-lethal dose of benzotriazole are presented. A part of the imago was taken from the population, afterwards they were bred on a standard fodder used for the Drosophila laboratory lines, this was done every ten years from 1980 to 2010. Female and male imago were separately subjected to a single exposure to benzotriazole in a semi-lethal dose.