What is meant by 'pesticide resistance'?

Pesticide resistance refers to the ability of a pest population to survive exposure to a pesticide that was once effective at controlling them. This phenomenon can occur when certain individuals within a pest population have genetic traits that allow them to withstand the effects of a pesticide. As these resistant individuals survive and reproduce, they can increase in number, leading to a population that is largely resistant to that pesticide. This poses significant challenges for pest management, as it reduces the options available for controlling these pests effectively and may necessitate the use of new, potentially more harmful pesticides or alternative management strategies.

In contrast, the effectiveness of pesticides over time focuses more on how well a pesticide continues to control pests as it is used, rather than the pests' ability to survive against it. The resistance of crops to pests deals with how well crops can withstand pest damage, which is a completely different concept. The frequency of pests in a given area simply refers to the number of pests present, which does not directly relate to their ability to survive pesticide treatments. Thus, the definition of pesticide resistance centers specifically on the characteristics of the pest population in relation to pesticide exposure.