An example of how an insect growth regulator functions in an insect is by:

Insect growth regulators (IGRs) function by mimicking or interfering with the hormones that regulate development in insects. One of the key roles of these hormones is to control the molting process, which is essential for an insect to grow and develop from one stage of its life cycle to the next. By interfering with molting, IGRs can prevent insects from successfully transitioning to the next developmental stage, ultimately disrupting their life cycle and reducing their population.

Specifically, IGRs can prevent larvae from becoming pupae or adults, effectively stunting their growth and reproductive capabilities. This impact on the molting process is a strategic way to manage insect populations without relying on traditional insecticides that may harm beneficial species and the environment.

The other options, while they may represent various effects that different types of pest management strategies could have on insects, do not specifically pertain to the primary mechanism of action of insect growth regulators. Therefore, the function of interfering with molting is a hallmark characteristic of how IGRs operate.