What is a characteristic of insect growth regulators?

Insect growth regulators (IGRs) are substances that mimic the hormones in insects, playing a crucial role in their development and growth. By imitating these hormones, IGRs can disrupt normal growth processes, preventing immature insects from developing into adults or causing adults to reproduce improperly. This action does not involve killing insects on contact, as IGRs generally do not act as direct poisons but instead interfere with the natural lifecycle of the insect by addressing hormonal balance.

This mechanism allows IGRs to effectively control insect populations over time, making them particularly useful in various pest management strategies. Rather than seeking immediate kills, their impact is often more subtle, requiring time to show results, which is why the effectiveness may not hinge on external factors like temperature or necessitate frequent applications compared to other pest control substances.