What is a common environmental factor that can affect pest populations?

Temperature and humidity levels are critical environmental factors that can significantly influence pest populations. These two elements directly affect the biology and behavior of pests, including their reproduction rates, life cycles, and survival. For instance, many pests thrive in warm and humid conditions, leading to increased breeding and potentially larger populations. Conversely, extreme temperatures or low humidity can stress pest populations, potentially decreasing their numbers.

The other choices do play roles in pest management and their effects; however, they do not encompass the broad environmental conditions that fundamentally influence pest survival and proliferation as temperature and humidity do. Factors such as the type of pesticide used and the time of year may affect pest control efforts or seasonal activity patterns but do not have the same direct and consistent impact on pest population dynamics as temperature and humidity. The amount of sunlight may influence certain pests, but its effect is often indirect and tied to temperature and humidity levels rather than being a primary environmental condition itself.