What is the difference between contact and systemic insecticides?

Contact insecticides and systemic insecticides serve different purposes in pest management based on their modes of action. The correct answer highlights that contact insecticides are designed to kill pests upon direct contact. They remain on the surface of the plant or pest and do not penetrate the plant tissue. This means they are effective against pests that come into direct contact with them.

On the other hand, systemic insecticides are absorbed into the plant's tissues and can kill insects that feed on the plant, even if they do not directly contact the insecticide. This absorption provides a longer-lasting effect and can protect against pests that might not be covered by contact applications.

Understanding these differences is crucial for selecting the appropriate type of insecticide for specific pest challenges. It also aids in developing integrated pest management strategies that maximize effectiveness while minimizing potential harm to beneficial organisms and the environment.