What happens to pesticides under conditions of resistance?

When pests develop resistance to pesticides, they undergo evolutionary changes that allow them to survive treatments that would typically kill them. This phenomenon means that the specific pesticides that were once effective may no longer work against these resistant populations. Over time, due to repeated exposure, a subset of the pest population survives and reproduces, leading to a greater prevalence of resistant individuals. As a result, the effectiveness of those pesticides diminishes, ultimately rendering them ineffective against certain pests. This situation highlights the importance of integrated pest management strategies, which include rotating different pest control methods to minimize the development of resistance and maintain the efficacy of available pesticides.