Determining when to apply a pesticide includes consideration of:

Determining when to apply a pesticide is fundamentally linked to understanding both the life cycle of the target pest and prevailing weather conditions.

The life cycle of a pest is crucial because pesticides are often most effective when applied at specific growth stages of the pest. For example, targeting pests during their larval stage, when they are most vulnerable, tends to yield better results in controlling pest populations. By knowing the pest's life cycle, an applicator can time pesticide applications to coincide with the most susceptible stages, thereby maximizing efficacy and minimizing unnecessary applications.

Weather conditions also play a significant role in the timing of pesticide applications. Factors such as temperature, humidity, and wind can influence the behavior of both the pest and the pesticide itself. For instance, a wet environment might enhance the effectiveness of certain pesticides, while high winds might lead to drift, causing pesticide to affect non-target areas, which is undesirable.

Considering these two critical factors— the life cycle of the pest and weather conditions—ensures that pesticide applications are strategic, effective, and environmentally responsible.