MDARD Mosquito Control Practice Exam 2025 – Complete Category 7F Study Guide

The development of resistance in mosquitoes to certain insecticides primarily occurs through natural selection and the overuse of specific chemical classes. When insecticides are applied, they kill susceptible mosquitoes, while those that have a genetic mutation that gives them resistance to the insecticide survive and reproduce. This means that the resistant individuals pass on their genes to the next generation, leading to a population that is increasingly resistant over time.

Repeated use of the same chemical classes can accelerate this process, as it puts selective pressure on the mosquito population. The more frequently a specific insecticide is used, the more likely it is that resistant mosquitoes will thrive, resulting in a growing percentage of the population that can survive the chemical treatments. This cycle emphasizes the importance of employing integrated pest management strategies that rotate or mix different classes of insecticides to mitigate the development of resistance.

While other factors such as mutation, environmental pollutants, and cross-breeding can influence mosquito populations and affect their biology, the central mechanism of resistance development is tied to natural selection and the repeated application of specific insecticides.