What is the definition of a pest?

A pest is defined as an undesirable organism that harms humans or desirable species. This definition encompasses a wide range of organisms that can cause damage to crops, transmit diseases to humans and livestock, or outcompete beneficial species. The focus is on the negative impact these organisms can have on agriculture, human health, and ecosystems.

In agriculture, for instance, pests can include insects like aphids or beetles that directly damage plants, weeds that compete for nutrients and water, or pathogens that cause diseases in crops. By categorizing these organisms as pests, it highlights the need for effective management strategies to mitigate their detrimental effects and protect the valuable assets in agriculture and human health.

The other options refer to beneficial organisms that contribute positively to ecosystems, such as those that aid in plant growth, pest control, or soil health, which does not align with the conventional understanding of what constitutes a pest.