Which of the following insecticides target insect eggs?

The correct answer is focused on the term "ovicidal," which specifically refers to insecticides designed to target eggs laid by insects. Ovicidal insecticides disrupt the early stages of an insect's life cycle by preventing the eggs from hatching or by killing the eggs directly. This mode of action is critical for effective pest management, as it helps reduce the overall population of insects before they reach more damaging life stages.

The other options, while related to pest control, have different targets. Larvicides are formulated to act on larvae, which are the immature stages of insects that have already hatched from eggs. Adulticides specifically target adult insects, often those that are actively feeding or mating. Insect Growth Regulators (IGRs) work by disrupting the developmental processes of insects at various life stages, but they do not directly kill eggs. Understanding these distinctions helps in selecting the appropriate pest control measures for effective crop protection.