What is referred to as the animal or plant on which the organism lives?

The correct answer is the term that describes the animal or plant on which an organism lives, often serving as a source of food or habitat for that organism. In the context of pesticides and pest management, a pest host is critical because it highlights the specific relationship between a pest and its preferred environment or food source. Understanding this relationship is vital for effective pest management strategies, as it allows applicators to identify, target, and manage the specific organisms that cause damage or negative effects in agriculture or horticulture.

Biological control refers to the use of natural predators or parasites to manage pest populations rather than the relationship between a pest and its host. Natural controls encompass the broader category of ecosystem dynamics that regulate pest populations without human intervention. Mechanical control involves physical methods of pest management, such as traps or barriers, rather than focusing on the host organism itself. Hence, the focus of the correct answer on the specific relationship between a pest and its host organism is what makes it the most appropriate choice in this context.