How does pesticide resistance develop in pest populations?

Pesticide resistance develops primarily due to the overuse of a particular pesticide. When a specific pesticide is applied repeatedly, it exerts selection pressure on the pest population. This means that those individuals that happen to possess genetic traits allowing them to survive the pesticide exposure are more likely to reproduce. Over time, as the susceptible individuals are eliminated, the proportion of resistant individuals in the population grows. This process is driven by the survival and reproduction of these resistant individuals, which leads to a larger population of pests that can survive future applications of the same pesticide.

In contrast, natural adaptation of pests is a broader concept and does not solely account for the specific mechanisms driven by pesticide use patterns. Completely avoiding pesticide use does not contribute to resistance development; rather, it may allow pest populations to remain vulnerable in the absence of chemical pressure. Lastly, the introduction of biopesticides typically involves employing different modes of action that can mitigate the development of resistance, as they do not exert the same selective pressure as conventional pesticides.