Which of the following is an example of biological pest control?

Biological pest control involves using living organisms to manage pest populations. Predatory insects serve as a prime example of this approach, as they naturally prey on pest species, reducing their numbers without the use of synthetic chemicals. This method leverages the natural predator-prey dynamics in ecosystems to create a more sustainable and environmentally friendly pest management strategy. For instance, ladybugs feed on aphids, and introducing them into a garden can help control an aphid infestation effectively.

In contrast, insecticides and herbicides involve the application of chemicals designed to kill pests or weeds, which do not fall under the category of biological control. Meanwhile, traps can be used to monitor or reduce pest populations but do not utilize biological agents or organisms intrinsic to the ecosystem's balance. Thus, predatory insects exemplify the principles of biological pest control by harnessing nature's own defenders against pests.