How can pests develop resistance to pesticides?

Pests can develop resistance to pesticides primarily through repeated exposure to those pesticides. In a population of pests, there may be some individuals that possess genetic traits making them less susceptible to the effects of a particular pesticide. When a pesticide is applied, it kills the susceptible individuals, while the resistant ones survive and reproduce. This leads to a greater proportion of resistant pests in subsequent generations. Over time, the continuous use of the same pesticide, especially if used at insufficient rates or not properly timed, can lead to an increased prevalence of those resistant traits within the pest population. As a result, the effectiveness of the pesticide diminishes, making it more challenging to control pest populations.

Other factors, like the migration of pests to new areas or changes in the environment, can play roles in pest dynamics, but they do not directly contribute to the development of resistance in the same way that selective survival and reproduction do. Consuming resistant crops would not apply since it pertains more to plant resistance than to pest resistance development.