Which of the following is a consequence of inadequate pest control?

Inadequate pest control can lead to increased pest resistance, which is a significant consequence in pest management. When pests are not effectively controlled, they are allowed to reproduce and proliferate, leading to a larger population that may potentially develop resistance to the control methods being used. This resistance arises from the survival of individuals with traits that make them less susceptible to treatments, such as pesticides. Over time, this can result in a pest population that is harder to manage, requiring higher doses of chemicals or more rigorous strategies, ultimately making pest control more challenging and costly.

The other options illustrate outcomes that would typically not arise from inadequate pest control. Improved crop yield suggests that pests are under control and not damaging plants, while enhanced biodiversity generally results from balanced ecosystems where pest populations are kept in check. A reduced need for intervention implies that pest populations are stable and manageable, which contrasts the reality of what happens when pest control is inadequate. Thus, increased pest resistance stands out as the most plausible and relevant consequence.