In pest management, what does the term "resistance" refer to?

In pest management, "resistance" specifically refers to the ability of a pest population to survive exposure to a pesticide that was previously effective in controlling that population. This phenomenon occurs when pests develop or acquire genetic traits that enable them to withstand the effects of the pesticide, leading to a situation where the pesticide is no longer effective. This can happen due to various factors, such as a high reproduction rate of pests, which allows resistant individuals to pass on their genes to the next generation. Over time, repeated use of the same pesticide can selectively eliminate susceptible individuals, while resistant ones survive and proliferate, diminishing the overall effectiveness of that pesticide.

The other answer choices address different concepts. While plants can exhibit resistance to pests, this does not pertain to the term as it is used in pest resistance context. The effectiveness of a pesticide over time relates more to its longevity and residual activity rather than the concept of resistance itself. Lastly, the reduction of pest populations through environmental changes describes an ecological approach rather than a direct interaction between pests and pesticides. Thus, the definition of resistance is uniquely encapsulated in the ability of pest populations to endure pesticide exposure.