What does residual pesticide mean?

Residual pesticide refers to a type of pesticide that remains active in the environment for extended periods after application. This characteristic is important because it allows for a prolonged effectiveness against targeted pests, providing ongoing control even after the initial application has been made. This residual action can lead to less frequent applications needed, which can be beneficial for both the efficacy of pest control efforts and overall management practices.

On the other hand, the other options focus on aspects that do not accurately define residual pesticides. Immediate effectiveness describes some pesticides but does not capture the long-lasting nature essential to residues; working in specific conditions pertains more to efficacy than to the concept of persistence; and requiring multiple applications applies to other types of pesticides that do not have lasting effectiveness.