What biological control method involves using predators like lady beetles?

The biological control method refers to the use of natural predators, parasites, or pathogens to manage pest populations. In this context, utilizing predators such as lady beetles exemplifies biological control because these insects feed on aphids and other pest species, effectively reducing their numbers naturally. This approach leverages the ecological relationships between organisms to keep pest populations in check, minimizing the need for synthetic pesticides.

Other methods of pest control mentioned in the options focus on different strategies. Cultural methods involve altering agricultural practices to improve plant health or reduce pest opportunities, mechanical methods include physical barriers or traps to eliminate pests, and chemical methods utilize synthetic substances to kill or deter pests. These strategies do not harness the natural predation relationships that are central to biological control.