<P> Many pest species produce large broods . This increases the probability of mutations and ensures the rapid expansion of resistant populations . </P> <P> Pest species had been exposed to natural toxins long before agriculture began . For example, many plants produce phytotoxins to protect them from herbivores . As a result, coevolution of herbivores and their host plants required development of the physiological capability to detoxify or tolerate poisons . </P> <P> Humans often rely almost exclusively on pesticides for pest control . This increases selection pressure towards resistance . Pesticides that fail to break down quickly contribute to selection for resistant strains even after they are no longer being applied . </P> <P> In response to resistance, managers may increase pesticide quantities / frequency, which exacerbates the problem . In addition, some pesticides are toxic toward species that feed on or compete with pests . This can allow the pest population to expand, requiring more pesticides . This is sometimes referred to as pesticide trap, or a pesticide treadmill, since farmers progressively pay more for less benefit . </P>

How do organisms develop resistance to antibiotics or pesticides