What is the general name for chemicals used to eliminate pest species that feed on crops?

The correct answer is pesticides, which are specific chemicals designed to eliminate or control pests that can harm crops. Pesticides encompass a wide range of substances, including insecticides (which target insects), herbicides (which control weeds), and fungicides (which deal with fungi). This broad classification makes pesticides critical in agriculture, as they help protect crops from various threats, thereby increasing yields and ensuring food security.

In the context of the question, while insect repellents specifically refer to substances designed to deter insects rather than eliminate them, fertilizers are used to enhance soil fertility and promote plant growth, not to address pest issues. Herbicides are a subset of pesticides but specifically target unwanted plants, or weeds. Thus, pesticides is the most comprehensive and accurate term to describe chemicals used broadly for pest control in agriculture.