What negative consequence can arise from the overuse of cover spray application?

The correct answer highlights an important issue in pest management concerning the overuse of cover spray applications. Overusing these applications can lead to the development of resistance among pest populations. This occurs when pests that survive the initial application reproduce, passing on their resistant traits to the next generation. Consequently, the effectiveness of the pesticide diminishes over time, prompting the need for higher doses or alternative chemicals to manage these pests.

While the other options suggest outcomes that may seem beneficial, they do not accurately reflect the realities of pesticide application. For instance, eliminating all pests is rarely achievable and can lead to imbalances in the ecosystem if not managed properly. The notion that cover sprays have no impact on beneficial insects is misleading, as these applications often affect non-target species, potentially harming beneficial insects that are crucial for pollination and natural pest control. Lastly, cover sprays typically do not promote biodiversity; rather, they can adversely impact the diverse range of organisms in a garden environment, leading to less overall ecosystem health.