Which type of pesticide can be applied in a manner that targets specific life stages of the pest?

Growth regulators are particularly effective in targeting specific life stages of pests because they are designed to disrupt the normal development processes of insects. These include juvenile hormones that prevent larvae from maturing into adults or compounds that cause premature molting or other developmental abnormalities.

By using growth regulators, pest control professionals can effectively manage pest populations by hindering their development rather than killing them outright. This can lead to a more sustainable approach, as it reduces the likelihood of pests developing resistance, as they may not be exposed to lethal doses of traditional pesticides.

In contrast, systemic pesticides work by being absorbed into the plant and targeting pests that feed on it. While effective, they do not specifically target certain life stages. Residual pesticides remain active on surfaces for a time and can kill pests on contact, but they do not discriminate between life stages. Broad-spectrum pesticides are designed to kill a wide range of pests and do not focus on specific stages of development.

Therefore, growth regulators are the most appropriate choice when the goal is to target particular life stages in pest control strategies.