What is an example of a biological control agent?

Ladybugs are an excellent example of a biological control agent because they are natural predators of aphids, which are common pests in many agricultural and gardening contexts. By introducing ladybugs into an environment where aphids are present, the population of aphids can be significantly reduced without the need for chemical pesticides. This method is part of integrated pest management strategies that emphasize the use of natural predators to control pest populations sustainably.

The other options listed—herbicides, fungicides, and rodenticides—are chemicals used to manage weeds, fungi, and rodents, respectively, and do not utilize living organisms to control pest populations. Herbicides target plant growth, fungicides manage fungal diseases, and rodenticides are designed to kill rodents. These substances can effectively manage pests but do not fall under the category of biological control, which relies on natural relationships in ecosystems.