Why does resistance to pesticides develop in pest species?

Resistance to pesticides in pest species is a natural process that occurs over time due to evolutionary factors. When pesticides are applied, they kill a large portion of the pest population. However, it is unlikely that any pesticide will eliminate 100% of the pests. Some individuals may possess genetic traits that provide them with a degree of resistance to the effects of the pesticide.

These surviving pests are then able to reproduce, passing their resistant traits onto their offspring. With repeated pesticide use, the proportion of resistant individuals in the population increases, leading to a situation where the pesticide becomes less effective over time. This phenomenon is a key concept in integrated pest management and highlights the importance of using a variety of pest control strategies to minimize the development of resistance.

The other choices do not accurately explain the biological basis of pesticide resistance. While cost and formulation may influence pesticide usage, resistance is fundamentally linked to the survival and reproduction of individuals within a population that possess resistance traits.