What does "residual activity" refer to when evaluating a pesticide?

Residual activity refers to the duration that a pesticide remains effective after it has been applied. This concept is crucial in pest control, as it informs pest control professionals about how long to expect the pesticide to continue working against target pests after the initial application. Pesticides with significant residual activity can provide ongoing protection and are particularly valuable in situations where pests are likely to return or where reinfestation is a concern.

Understanding residual activity helps in making informed decisions regarding the timing of reapplications and enhances the overall effectiveness of a pest management strategy. In contrast, other aspects such as the immediate effectiveness or concentration of pesticide used do not address the length of time that the pesticide can actively control pests after it has been applied.