What environmental change can lead to an increase in mosquito populations?

Increased standing water is a significant environmental change that can lead to an increase in mosquito populations. Mosquitoes require standing water for their breeding and development. Female mosquitoes lay their eggs in stagnant water sources such as ponds, marshes, containers, and even puddles. When there is an increase in available standing water, whether due to heavy rainfall, flooding, or improper drainage, it creates more suitable habitats for mosquitoes to reproduce. As a result, more mosquitoes can emerge from these water sources, leading to a larger population.

The other options, while they may influence mosquito populations in different ways, do not directly encourage breeding as effectively as standing water does. Decreased humidity can create less favorable conditions for mosquito survival, while lower temperatures tend to slow down their metabolism and reduce their activity. Reduced sunlight may also negatively affect their growth and reproduction, but it is standing water that remains the most crucial factor for their breeding cycle.