Which type of pesticides is generally less susceptible to the development of resistance?

Insect growth regulators, often abbreviated as IGRs, are a specific category of pesticides designed to disrupt the development and growth of insects. They work by mimicking hormones or interfering with the normal development processes, such as molting. This targeted mode of action affects only certain life stages or developmental processes of the insect, rather than killing the organism outright like other pesticides.

Because IGRs act on specific growth processes, they generally exert less selective pressure on the target population. This means that the likelihood of a population developing resistance is lower compared to other types of pesticides that have broad-spectrum effects or that act on critical survival mechanisms in a fast and lethal manner. In contrast, broad-spectrum pesticides can eliminate a wide variety of pests, which may lead to a higher chance of some individuals surviving and developing resistance.

Contact pesticides are those that must come into direct contact with the pest to be effective. This can also contribute to resistance over time, as pests can develop ways to avoid exposure. Organophosphates, a group of pesticides that inhibit enzyme functions in pests, also have a higher potential for resistance development due to their widespread and often non-selective use.

In summary, the targeted and highly specific action of insect growth regulators contributes to their reduced