In flea control, IGRs primarily affect which life stage?

• A. Egg Development Stage
• B. Egg Stage
• C. Pupae
• D. Adult Fleas

Answer: (B)

IGRs work by stopping fleas from completing their development, not by killing adults. They mimic juvenile hormone in insects, so developing fleas can’t progress from immature stages to the next stage. In fleas, this means the eggs and early immature stages are where the action is most evident, preventing eggs from hatching and hindering larvae from maturing into adults. Because of this, the egg stage is the primary target of IGRs. Pupae and adults aren’t the stages that these products are designed to disrupt, which is why those options fit less well.