Which term refers to infectious organisms that injure or kill their hosts in pest management?

The term that refers to infectious organisms which injure or kill their hosts in pest management is "pathogens." Pathogens are biological agents that can cause disease in organisms, including plants, animals, and humans. In the context of pest management, they are often used as biological control agents to reduce pest populations. This could include bacteria, viruses, fungi, and nematodes that specifically target pest insects or other organisms, disrupting their lifecycle or causing disease, leading to their decline or death.

Predators and parasites are different concepts within the realm of biological control. Predators actively hunt and consume their prey, whereas parasites live in or on a host organism, deriving nutrients at the host's expense but typically do not kill their host outright. Microbials refers to microorganisms in general, which can include pathogens but does not specifically denote those that cause disease. Thus, while other options represent aspects of pest management, they do not directly address the injury or death caused by infectious organisms as precisely as pathogens do.