Determining when to apply a pesticide includes considering the:

The correct answer focuses on the importance of understanding both the life cycle of the pest and prevailing weather conditions when deciding the timing for pesticide application.

The life cycle of a pest is crucial because different stages of development may have varying vulnerabilities to pesticide treatment. For instance, applying a pesticide when pests are in their most susceptible life stage, such as their larval or nymph stages, can lead to a more successful control effort. Additionally, knowing the pest's life cycle helps in establishing the optimal timing for application to coincide with peak pest populations.

Weather conditions also play a significant role in the effectiveness of pesticide application. Certain weather factors, such as temperature, humidity, and rainfall, can affect pesticide efficacy, absorption, and potential runoff. For example, applying pesticides in windy conditions may lead to drift, while rainfall shortly after application could wash away the pesticide before it has had the chance to work effectively.

Understanding both the life cycle of the pest and weather conditions thus ensures that pesticide application is strategically timed for maximum impact, minimizing potential waste and environmental harm.