In terms of application, what differentiates residual pesticides from others?

Residual pesticides are characterized by their ability to remain active and effective over extended periods after application. This prolonged activity is what differentiates them from non-residual pesticides, which typically act quickly but degrade or become ineffective soon after application. Because residual pesticides continue to provide protection against pests for days, weeks, or even months, they are often utilized in situations where ongoing pest management is critical.

This extended effectiveness is advantageous for both agricultural practices and pest control, as it helps reduce the frequency of applications, resulting in lower labor and operational costs in the long term. Additionally, residual pesticides can help manage pest populations over time, creating a more sustainable approach to pest management.

The other options, while they may relate to different types of pesticides, do not define the unique characteristic of residual pesticides in terms of their application and effectiveness. Immediate pest killing is more indicative of contact pesticides, safety for non-target organisms pertains to selectivity and formulation, and price can vary widely depending on the product and application context rather than being a defining trait of residual pesticides.