Which factor can lead to increased resistance in mosquito populations?

Frequent application of the same pesticide is a primary factor that can lead to increased resistance in mosquito populations. When a specific pesticide is repeatedly used within the same area, the mosquitoes that are susceptible to that pesticide are killed off. However, this leaves behind those individuals that may have a natural resistance to the chemical. Over time, as the resistant mosquitoes continue to breed, the population becomes increasingly composed of these resistant individuals. This process, known as selection pressure, diminishes the overall effectiveness of the pesticide in controlling the mosquito population, making future applications less effective.

In contrast, varied breeding locations, natural predation by other insects, and wetter seasonal conditions do not inherently contribute to resistance development in the same manner. While varied breeding locations can impact mosquito population dynamics and distribution, they do not directly influence resistance. Natural predation can help control mosquito populations but does not lead to resistance. Wetter seasonal conditions can create favorable environments for mosquito breeding but do not play a role in the development of chemical resistance. Thus, the frequent use of the same pesticide is the pivotal factor linked to increased resistance.